ITI Members: May 2007- May 2009 Publications
Publications authored and co-authored by Stanford Institute for Immunity, Transplantation and Infection (ITI) are listed below by month.
ITI Faculty and Researchers' Publication for May 2009
MAY 2009 ITI PUBLICATIONS – 41
1) Microbiology. 2009 Apr 30. [Epub ahead of print]
Genomic DNA microarray comparison of gene expression patterns in Paracoccidioides brasiliensis mycelia and yeasts in vitro.
Monteiro JP, Clemons KV, Mirels LF, Coller JA, Wu TD, Shankar J, Lopes CR, Stevens DA. Stanford University;
Paracoccidioides brasiliensis is a thermally dimorphic fungus, which causes the most prevalent systemic mycosis in Latin America. Infection is initiated by inhalation of conidia or mycelial fragments by the host, followed by further differentiation into the yeast form. Information regarding gene expression by either form has been rarely addressed with respect to multiple time points of growth in culture. Here, we report on the construction of a genomic DNA microarray, covering approximately 25% of the organism's genome, and its utilization in identifying genes and gene expression patterns during growth in vitro. Cloned, amplified inserts from randomly sheared gDNA and known control genes were printed onto glass slides to generate a microarray of over 12,000 elements. To examine gene expression, mRNA was extracted and amplified from mycelial or yeast cultures grown in semi-defined medium for 5, 8 and 14 days. Principal components analysis and hierarchical clustering indicated that yeast gene expression profiles differed greatly from mycelia, especially at earlier time-points, and that mycelial gene expression changed less than it did on yeasts over time. Genes, upregulated in yeasts, were found to be involved in methionine/cysteine metabolism, respiratory processes, metabolic processes (sugars, amino acids, proteins and lipids), transporters (small peptides, sugar, ions and toxin), regulatory proteins and transcription factors. Mycelia genes involved in processes such as cell division, protein catabolism, nucleotide biosynthesis and toxin and sugar transporters showed differential expression. Sequenced clones were compared with Histoplasma capsulatum and Coccidioides posadasii genome sequences to assess potentially common pathways across species, such as sulfur and lipid metabolism, amino acid transporters, transcription factors and genes possibly related to virulence. We also analyzed gene expression with time in culture and found that while transposable elements and components of respiratory pathways tended to increase in expression with time, genes coding for ribosomal structural proteins and protein catabolism tended to sharply decrease in expression over time, particularly in yeast. These findings expand knowledge about the different morphologic forms of P. brasiliensis during growth in culture. PMID: 19406900 [PubMed - as supplied by publisher]
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2) Clin Immunol. 2009 Apr 27. [Epub ahead of print]
Breaking old paradigms: Th17 cells in autoimmune arthritis.
Peck A, Mellins ED.
Department of Pediatrics, Division of Immunology and Transplantation Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Aberrant helper T cell activation has been implicated in the pathogenesis of an array of autoimmune diseases. In this review, we summarize evidence that suggests the involvement of a novel T cell subset, the Th17 lineage, in rheumatoid arthritis. In particular, we focus on the role of Th17 cells in inducing and perpetuating the chronic inflammation, cartilage damage, and bone erosion that are hallmark phases of joint destruction and consider current and emerging therapies that seek to disrupt the inflammatory Th17 network and shift the immune system back towards homeostasis. PMID: 19403336 [PubMed - as supplied by publisher]
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3) Cancer Prev Res (Phila Pa). 2009 Apr 28. [Epub ahead of print]
Early Detection of Oral Neoplasia: Watching with New Eyes.
Kelloff GJ, Sigman CC, Contag CH.
Authors' Affiliations: 1National Cancer Institute, Division of Cancer Treatment and Diagnosis, Cancer Imaging Program, Rockville, Maryland; 2CCS Associates, Mountain View, California; and 3Departments of Pediatrics, Microbiology and Immunology, and Radiology and the Molecular Imaging Program at Stanford, Stanford University School of Medicine, Stanford, California.
PMID: 19401527 [PubMed - as supplied by publisher]
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4) Mult Scler. 2009 May;15(5):529-30.
Systems biology for identification of molecular networks in multiple sclerosis.
Han M, Steinman L.
Department of Neurology and Neurological Sciences, Stanford University, Stanford, California, USA mayhan@stanford.edu.
PMID: 19389747 [PubMed - in process
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5) Transfusion. 2009 Mar 31. [Epub ahead of print]
Implementation of a two-specimen requirement for verification of ABO/Rh for blood transfusion.
Goodnough LT, Viele M, Fontaine MJ, Jurado C, Stone N, Quach P, Chua L, Chin ML, Scott R, Tokareva I, Tabb K, Sharek PJ.
From the Departments of Pathology, Medicine, and Pediatrics, Stanford University School of Medicine; Stanford Hospital and Clinics; and the Department of Quality Management, Lucile Packard Children's Hospital at Stanford University, Stanford, California.
BACKGROUND: This study presents our implementation of a two-specimen requirement with no prior record of ABO/Rh to verify patients' blood type before transfusion. MATERIALS AND METHODS: Blood type verification was introduced, discussed, approved, and implemented over a 12-month period (May 2007 to May 2008). Potential barriers and impact on benchmark indicators were identified and tracked. RESULTS: Inpatient identification and/or specimen labeling for nursing and laboratory phlebotomists baseline corrected error rates were 1:467 and 1:5555, respectively. This study therefore sought and obtained approval to initiate a new policy of blood type verification before blood transfusion. Compliance in turnaround time (TAT) before and after implementation for completion of STAT type and screen/crossmatch within 60 minutes worsened marginally, from 90% to 80%. The impact on use of O-, uncrossmatched blood was found to be manageable. Seven (of 25 total) recorded electronic complaints were received after implementation. The corrected error rate for nurse phlebotomy draws after implementation was 1:630. CONCLUSION: Despite the lack of an instigating event, verification of blood type before blood transfusion was successfully implemented. An impact on resources and benchmark indicators such as TAT can be anticipated and managed. Further process improvement efforts will be needed to ensure safety (e.g., at time of blood transfusion) for patients receiving blood transfusions. ABO/Rh verification may be necessary even after future implementation of bar coding and/or RFID chips, because human errors continue to occur even with systems improvements. PMID: 19389026 [PubMed - as supplied by publisher
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6) Obstet Gynecol. 2009 May;113(5):1027-1037.
Ovarian Conservation at the Time of Hysterectomy and Long-Term Health Outcomes in the Nurses' Health Study.
Parker WH, Broder MS, Chang E, Feskanich D, Farquhar C, Liu Z, Shoupe D, Berek JS, Hankinson S, Manson JE.
From the 1John Wayne Cancer Institute at Saint John's Health Center, Santa Monica, California; 2UCLA School of Medicine, Los Angeles, California; 3Partnership for Health Analytic Research, Los Angeles, California; 4Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts; 5School of Medicine, University of Auckland, Auckland, New Zealand; 6Cerner Health Insights, Beverly Hills, California; 7Keck School of Medicine, University of Southern California, Los Angeles, California; 8Stanford University School of Medicine, Stanford, California; 9Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts; and 10Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
OBJECTIVE:: To report long-term health outcomes and mortality after oophorectomy or ovarian conservation. METHODS:: We conducted a prospective, observational study of 29,380 women participants of the Nurses' Health Study who had a hysterectomy for benign disease; 16,345 (55.6%) had hysterectomy with bilateral oophorectomy, and 13,035 (44.4%) had hysterectomy with ovarian conservation. We evaluated incident events or death due to coronary heart disease (CHD), stroke, breast cancer, ovarian cancer, lung cancer, colorectal cancer, total cancers, hip fracture, pulmonary embolus, and death from all causes. RESULTS:: Over 24 years of follow-up, for women with hysterectomy and bilateral oophorectomy compared with ovarian conservation, the multivariable hazard ratios (HRs) were 1.12 (95% confidence interval [CI] 1.03-1.21) for total mortality, 1.17 (95% CI 1.02-1.35) for fatal plus nonfatal CHD, and 1.14 (95% CI 0.98-1.33) for stroke. Although the risks of breast (HR 0.75, 95% CI 0.68-0.84), ovarian (HR 0.04, 95% CI 0.01-0.09, number needed to treat=220), and total cancers (HR 0.90, 95% CI 0.84-0.96) decreased after oophorectomy, lung cancer incidence (HR=1.26, 95% CI 1.02-1.56, number needed to harm=190), and total cancer mortality (HR=1.17, 95% CI 1.04-1.32) increased. For those never having used estrogen therapy, bilateral oophorectomy before age 50 years was associated with an increased risk of all-cause mortality, CHD, and stroke. With an approximate 35-year life span after surgery, one additional death would be expected for every nine oophorectomies performed. CONCLUSION:: Compared with ovarian conservation, bilateral oophorectomy at the time of hysterectomy for benign disease is associated with a decreased risk of breast and ovarian cancer but an increased risk of all-cause mortality, fatal and nonfatal coronary heart disease, and lung cancer. In no analysis or age group was oophorectomy associated with increased survival. LEVEL OF EVIDENCE:: II. PMID: 19384117 [PubMed - as supplied by publisher
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7) J Med Microbiol. 2009 May;58(Pt 5):671-3.
Bartholin's abscess caused by hypermucoviscous Klebsiella pneumoniae.
Pinsky BA, Baron EJ, Janda JM, Banaei N.
1Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Klebsiella pneumoniae serogroups displaying the hypermucoviscosity phenotype are associated with a distinct clinical syndrome characterized by liver abscesses, bacteraemia and metastatic lesions. We describe here what we believe to be the first reported case of hypermucoviscous K. pneumoniae causing a superficial Bartholin's abscess in the absence of systemic involvement. PMID: 19369531 [PubMed - in process]
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8) J Rheumatol. 2009 Apr 15. [Epub ahead of print]
Less Radiographic Progression with Adalimumab Plus Methotrexate Versus Methotrexate Monotherapy Across the Spectrum of Clinical Response in Early Rheumatoid Arthritis.
Emery P, Genovese MC, van Vollenhoven R, Sharp JT, Patra K, Sasso EH.
From Leeds Teaching Hospital, Rheumatology, Leeds, United Kingdom; Stanford University Medical Center, Division of Rheumatology, Palo Alto, California, USA; Karolinska University Hospital and Karolinska Institute, Rheumatology Unit, Stockholm, Sweden; University of Washington, Seattle, Washington; Abbott Laboratories, Parsippany, New Jersey; and Abbott Laboratories, Abbott Park, Illinois, USA.
OBJECTIVE: To determine the relationship between radiographic progression and clinical response for adalimumab plus methotrexate (MTX) versus either monotherapy in patients with early rheumatoid arthritis (RA) in the PREMIER study. METHODS: Patients with early RA who received adalimumab plus MTX (n = 240), adalimumab (n = 222), or MTX (n = 216) were grouped by American College of Rheumatology (ACR) response, 28-joint Disease Activity Score (DAS28), or remission-like state [tender joint count (TJC) = 0; DAS28 < 2.6; swollen joint count = 0;ACR100] at 26 and 104 weeks. Radiographic progression was assessed by cumulative probability plots, mean changes in total Sharp score (DeltaTSS), and percentages of progressors (DeltaTSS > 0.5). RESULTS: Across the spectrum of clinical outcomes, including ACR20 nonresponses and remission- like responses, therapy with adalimumab plus MTX permitted less radiographic progression at Weeks 26 and 104 than MTX monotherapy. Adalimumab monotherapy was generally intermediate. A strong, proportional relationship was observed between clinical response and radiographic efficacy only for MTX monotherapy. The monotherapies approximated the radiographic efficacy of adalimumab plus MTX only among remission-like responders, although progression was significantly greater with MTX monotherapy versus adalimumab plus MTX for patients with TJC = 0. Concurrent clinical (DAS28 < 2.6) and radiographic (DeltaTSS </= 0.5) remission was significantly more frequent at Week 104 with adalimumab plus MTX (45%) than with adalimumab (25%) or MTX (18%) monotherapy. CONCLUSION: In patients with early RA, adalimumab plus MTX resulted in less radiographic progression than MTX monotherapy across the spectrum of clinical response, including ACR20 nonresponses and remission-like responses.PMID: 19369462 [PubMed - as supplied by publisher
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9) PLoS ONE. 2009;4(4):e5206. Epub 2009 Apr 15.
A novel method for detection of phosphorylation in single cells by surface enhanced Raman scattering (SERS) using composite organic-inorganic nanoparticles (COINs).
Shachaf CM, Elchuri SV, Koh AL, Zhu J, Nguyen LN, Mitchell DJ, Zhang J, Swartz KB, Sun L, Chan S, Sinclair R, Nolan GP.
Department of Microbiology & Immunology, Stanford University, Stanford, California, United States of America.
BACKGROUND: Detection of single cell epitopes has been a mainstay of immunophenotyping for over three decades, primarily using fluorescence techniques for quantitation. Fluorescence has broad overlapping spectra, limiting multiplexing abilities. METHODOLOGY/PRINCIPAL FINDINGS: To expand upon current detection systems, we developed a novel method for multi-color immuno-detection in single cells using "Composite Organic-Inorganic Nanoparticles" (COINs) Raman nanoparticles. COINs are Surface-Enhanced Raman Scattering (SERS) nanoparticles, with unique Raman spectra. To measure Raman spectra in single cells, we constructed an automated, compact, low noise and sensitive Raman microscopy device (Integrated Raman BioAnalyzer). Using this technology, we detected proteins expressed on the surface in single cells that distinguish T-cells among human blood cells. Finally, we measured intracellular phosphorylation of Stat1 (Y701) and Stat6 (Y641), with results comparable to flow cytometry. CONCLUSIONS/SIGNIFICANCE: Thus, we have demonstrated the practicality of applying COIN nanoparticles for measuring intracellular phosphorylation, offering new possibilities to expand on the current fluorescent technology used for immunoassays in single cells.PMID: 19367337 [PubMed - in process] PMCID: PMC2666268
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10) J Cell Sci. 2009 May 1;122(Pt 9):1441-51. Epub 2009 Apr 14.
LC3-mediated fibronectin mRNA translation induces fibrosarcoma growth by increasing connective tissue growth factor.
Ying L, Lau A, Alvira CM, West R, Cann GM, Zhou B, Kinnear C, Jan E, Sarnow P, Van de Rijn M, Rabinovitch M.
Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, 94305, USA.
Previously, we related fibronectin (Fn1) mRNA translation to an interaction between an AU-rich element in the Fn1 3' UTR and light chain 3 (LC3) of microtubule-associated proteins 1A and 1B. Since human fibrosarcoma (HT1080) cells produce little fibronectin and LC3, we used these cells to investigate how LC3-mediated Fn1 mRNA translation might alter tumor growth. Transfection of HT1080 cells with LC3 enhanced fibronectin mRNA translation. Using polysome analysis and RNA-binding assays, we show that elevated levels of translation depend on an interaction between a triple arginine motif in LC3 and the AU-rich element in Fn1 mRNA. Wild-type but not mutant LC3 accelerated HT1080 cell growth in culture and when implanted in SCID mice. Comparison of WT LC3 with vector-transfected HT1080 cells revealed increased fibronectin-dependent proliferation, adhesion and invasion. Microarray analysis of genes differentially expressed in WT and vector-transfected control cells indicated enhanced expression of connective tissue growth factor (CTGF). Using siRNA, we show that enhanced expression of CTGF is fibronectin dependent and that LC3-mediated adhesion, invasion and proliferation are CTGF dependent. Expression profiling of soft tissue tumors revealed increased expression of both LC3 and CTGF in some locally invasive tumor types.PMID: 19366727 [PubMed - in process]
PMCID: PMC2672968 [Available on 2009/11/01
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11) Blood. 2009 Apr 24. [Epub ahead of print]
Lymphoid tissue specific homing of bone marrow-derived dendritic cells.
Creusot RJ, Yaghoubi SS, Chang P, Chia J, Contag CH, Gambhir SS, Fathman CG.
Department of Medicine, Division of Immunology & Rheumatology, Stanford University, Stanford, CA, United States.
Because of their potent immunoregulatory capacity, dendritic cells (DCs) have been exploited as therapeutic tools to boost immune responses against tumors or pathogens, or dampen autoimmune or allergic responses. Murine bone marrow-derived DCs (BM-DCs) are the closest known equivalent of the blood monocyte-derived DCs that have been used for human therapy. Current imaging methods have proven unable to properly address the migration of injected DCs to small and deep tissues in mice and humans. This study presents the first extensive analysis of BM-DC homing to lymph nodes (and other selected tissues) after intravenous and intraperitoneal inoculation. Following intravenous delivery, DCs accumulated in the spleen, and preferentially in the pancreatic and lung-draining lymph nodes. In contrast, DCs injected intraperitoneally were found predominantly in peritoneal lymph nodes (pancreatic in particular), and in omentum-associated lymphoid tissue. This uneven distribution of BM-DCs, independent of the mouse strain and also observed within pancreatic lymph nodes, resulted in the uneven induction of an immune response in different lymphoid tissues. These data have important implications for the design of systemic cellular therapy with DCs, and in particular underlie a previously unsuspected potential for specific treatment of diseases such as autoimmune diabetes and pancreatic cancer.PMID: 19363220 [PubMed - as supplied by publisher]
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12) J Vasc Interv Radiol. 2009 May;20(5):606-13. Epub 2009 Apr 5.
Incorporating cone-beam CT into the treatment planning for yttrium-90 radioembolization.
Louie JD, Kothary N, Kuo WT, Hwang GL, Hofmann LV, Goris ML, Iagaru AH, Sze DY.
Department of Radiology, Stanford University Medical Center, CA 94305-5642, USA. jdlouie@stanford.edu
PURPOSE: To prepare for yttrium-90 ((90)Y) microsphere radioembolization therapy, digital subtraction angiography (DSA) and technetium- 99m-labeled macroaggregated albumin ((99m)Tc MAA) scintigraphy are used for treatment planning and detection of potential nontarget embolization. The present study was performed to determine if cone-beam computed tomography (CBCT) affects treatment planning as an adjunct to these conventional imaging modalities. MATERIALS AND METHODS: From March 2007 to August 2008, 42 consecutive patients (21 men, 21 women; mean age, 59 years; range, 21-75 y) who underwent radioembolization were evaluated by CBCT in addition to DSA and (99m)Tc MAA scintigraphy during treatment planning, and their records were retrospectively reviewed. The contrast-enhanced territories shown by CBCT with selective intraarterial contrast agent administration were used to predict intrahepatic and possible extrahepatic distribution of microspheres. RESULTS: In 22 of 42 cases (52%), extrahepatic enhancement or incomplete tumor perfusion seen on CBCT affected the treatment plan. In 14 patients (33%), the findings were evident exclusively on CBCT and not detected by DSA. When comparing CBCT versus (99m)Tc MAA scintigraphy, CBCT showed eight cases of extrahepatic enhancement (19%) that were not evident on (99m)Tc MAA imaging. CBCT findings directed the additional embolization of vessels or repositioning of the catheter for better contrast agent and microsphere distribution. One case of gastric ulcer from nontarget embolization caused by reader error was observed. CONCLUSIONS: CBCT can provide additional information about tumor and tissue perfusion not currently detectable by DSA or (99m)Tc MAA imaging, which should optimize (90)Y microsphere delivery and reduce nontarget embolization.PMID: 19345589 [PubMed - in process
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13) Am J Transplant. 2009 Mar 16. [Epub ahead of print]
Transarterial Chemoinfusion for Hepatocellular Carcinoma as Downstaging Therapy and a Bridge toward Liver Transplantation.
De Luna W, Sze DY, Ahmed A, Ha BY, Ayoub W, Keeffe EB, Cooper A, Esquivel C, Nguyen MH.
Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University School of Medicine, Stanford, CA.
Favorable outcomes after liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) are well described for patients who fall within defined tumor criteria. The effectiveness of tumor therapies to maintain tumor characteristics within these criteria or to downstage more advanced tumors to fall within these criteria is not well understood. The aim of this study was to examine the response to transcatheter arterial chemoinfusion (TACI) in HCC patients awaiting LT and its efficacy for downstaging or bridging to transplantation. We performed a retrospective study of 248 consecutive TACI cases in 122 HCC patients at a single U.S. medical center. Patients were divided into two groups: those who met the Milan criteria on initial HCC diagnosis (n = 95) and those with more advanced disease (n = 27). With TACI treatment, 87% of the Milan criteria group remained within the Milan criteria and 63% of patients with more advanced disease were successfully downstaged to fall within the Milan criteria. In conclusion, TACI appears to be an effective treatment as a bridge to LT for nearly 90% patients presenting within the Milan criteria and an effective downstaging modality for over half of those whose tumor burden was initially beyond the Milan criteria. PMID: 19344435 [PubMed - as supplied by publisher
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14) AJR Am J Roentgenol. 2009 Apr;192(4):1090-6.
Percutaneous implantation of fiducial markers for imaging-guided radiation therapy.
Kothary N, Dieterich S, Louie JD, Chang DT, Hofmann LV, Sze DY.
Department of Interventional Radiology, Stanford University Medical Center, 300 Pasteur Dr., H3630, Stanford, CA 94305, USA. kothary@stanford.edu
OBJECTIVE: The use of imaging-guided radiation therapy (IGRT) to treat thoracic and abdominal tumors is increasing. In this article, we review the process of IGRT and describe techniques to implant fiducial markers in the optimal geometry. CONCLUSION: Implantation of fiducial markers can be challenging. A better understanding of the physics of IGRT can help optimize fiducial marker placement for precise tumor targeting. PMID: 19304719 [PubMed - indexed for MEDLINE
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15) Biotechniques. 2009 Jan;46(1):44-50.
Conditional protein stabilization via the small molecules Shld-1 and rapamycin increases the signal-to-noise ratio with tet-inducible gene expression.
Almogy G, Nolan GP.
The Department of Microbiology and Immunology, Stanford University School of Medicine, Palo Alto, CA 94305, USA.
Cellular mechanisms control one or more of the three basic levels of regulation (transcription, translation, and protein activity/locality), allowing for finely tuned spatial and temporal regulation of protein expression patterns. Gene regulation constructs in wide use today often employ a constitutively expressed transcription factor whose activity is determined by the presence or absence of a small molecule. A case in point is the tet transcription system, wherein transcription is regulated by doxycycline (Dox), allowing the researcher to turn protein expression on or off depending on the presence/absence of Dox. However in many applications of that system, there is basal transcription from the promoter element that is independent of Dox. Moreover, in vivo, heterogeneous distribution of Dox leads to concurrent differences in gene expression. We addressed these limitations by introducing conditional destabilizing elements to the system. First, we created a transactivator protein fusion regulated at the additional level of protein stability. This modification enabled a system that demonstrated an off state that is less sensitive to variations in Dox concentrations. We also regulated the stability of the protein expressed from the tet operator cassette, observing greatly improved signal-to-noise ratios. The results underscore how investigator-defined regulation at multiple levels of protein expression can attain afiner degree of control over the final expression of introduced genes. PMID: 19301621 [PubMed - indexed for MEDLINE
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16) Ann Intern Med. 2009 Apr 7;150(7):493-5. Epub 2009 Mar 2.
Comment in: Ann Intern Med. 2009 Apr 7;150(7):498.
Toward a 21st-century health care system: recommendations for health care reform.
Arrow K, Auerbach A, Bertko J, Brownlee S, Casalino LP, Cooper J, Crosson FJ, Enthoven A, Falcone E, Feldman RC, Fuchs VR, Garber AM, Gold MR, Goldman D, Hadfield GK, Hall MA, Horwitz RI, Hooven M, Jacobson PD, Jost TS, Kotlikoff LJ, Levin J, Levine S, Levy R, Linscott K, Luft HS, Mashal R, McFadden D, Mechanic D, Meltzer D, Newhouse JP, Noll RG, Pietzsch JB, Pizzo P, Reischauer RD, Rosenbaum S, Sage W, Schaeffer LD, Sheen E, Silber BM, Skinner J, Shortell SM, Thier SO, Tunis S, Wulsin L Jr, Yock P, Nun GB, Bryan S, Luxenburg O, van de Ven WP.
Department of Economics, Stanford University, Stanford, CA 94305-6072, USA.
The coverage, cost, and quality problems of the U.S. health care system are evident. Sustainable health care reform must go beyond financing expanded access to care to substantially changing the organization and delivery of care. The FRESH-Thinking Project (www.fresh-thinking.org) held a series of workshops during which physicians, health policy experts, health insurance executives, business leaders, hospital administrators, economists, and others who represent diverse perspectives came together. This group agreed that the following 8 recommendations are fundamental to successful reform: 1. Replace the current fee-for-service payment system with a payment system that encourages and rewards innovation in the efficient delivery of quality care. The new payment system should invest in the development of outcome measures to guide payment. 2. Establish a securely funded, independent agency to sponsor and evaluate research on the comparative effectiveness of drugs, devices, and other medical interventions. 3. Simplify and rationalize federal and state laws and regulations to facilitate organizational innovation, support care coordination, and streamline financial and administrative functions. 4. Develop a health information technology infrastructure with national standards of interoperability to promote data exchange. 5. Create a national health database with the participation of all payers, delivery systems, and others who own health care data. Agree on methods to make de-identified information from this database on clinical interventions, patient outcomes, and costs available to researchers. 6. Identify revenue sources, including a cap on the tax exclusion of employer-based health insurance, to subsidize health care coverage with the goal of insuring all Americans. 7. Create state or regional insurance exchanges to pool risk, so that Americans without access to employer-based or other group insurance could obtain a standard benefits package through these exchanges. Employers should also be allowed to participate in these exchanges for their employees' coverage. 8. Create a health coverage board with broad stakeholder representation to determine and periodically update the affordable standard benefit package available through state or regional insurance exchanges.PMID: 19258550 [PubMed - indexed for MEDLINE]
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17) Proc Natl Acad Sci U S A. 2009 Mar 17;106(11):4148-53. Epub 2009 Feb 27.
Identifying compartment-specific non-HLA targets after renal transplantation by integrating transcriptome and "antibodyome" measures.
Li L, Wadia P, Chen R, Kambham N, Naesens M, Sigdel TK, Miklos DB, Sarwal MM, Butte AJ.
Department of Pediatrics, Blood and Marrow Transplantation Division, Stanford University, 300 Pasteur Drive, Stanford, CA 94304, USA.
We have conducted an integrative genomics analysis of serological responses to non-HLA targets after renal transplantation, with the aim of identifying the tissue specificity and types of immunogenic non-HLA antigenic targets after transplantation. Posttransplant antibody responses were measured by paired comparative analysis of pretransplant and posttransplant serum samples from 18 pediatric renal transplant recipients, measured against 5,056 unique protein targets on the ProtoArray platform. The specificity of antibody responses were measured against gene expression levels specific to the kidney, and 2 other randomly selected organs (heart and pancreas), by integrated genomics, employing the mapping of transcription and ProtoArray platform measures, using AILUN. The likelihood of posttransplant non-HLA targets being recognized preferentially in any of 7 microdissected kidney compartments was also examined. In addition to HLA targets, non-HLA immune responses, including anti-MICA antibodies, were detected against kidney compartment-specific antigens, with highest posttransplant recognition for renal pelvis and cortex specific antigens. The compartment specificity of selected antibodies was confirmed by IHC. In conclusion, this study provides an immunogenic and anatomic roadmap of the most likely non-HLA antigens that can generate serological responses after renal transplantation. Correlation of the most significant non-HLA antibody responses with transplant health and dysfunction are currently underway.
PMID: 19251643 [PubMed - indexed for MEDLINE]
PMCID: PMC2657434 [Available on 2009/09/17
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18) Eur J Immunol. 2009 Mar;39(3):763-75.
Differences in Bcl-2 expression by T-cell subsets alter their balance after in vivo irradiation to favor CD4+Bcl-2hi NKT cells.
Yao Z, Liu Y, Jones J, Strober S.
Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, CA 94305-5166, USA.
Although it is well known that in vivo radiation depletes immune cells via the Bcl-2 apoptotic pathway, a more nuanced analysis of the changes in the balance of immune-cell subsets is needed to understand the impact of radiation on immune function. We show the balance of T-cell subsets changes after increasing single doses of total body irradiation (TBI) or after fractionated irradiation of the lymphoid tissues (TLI) of mice due to differences in radioresistance and Bcl-2 expression of the NKT-cell and non-NKT subsets to favor CD4(+)Bcl-2(hi) NKT cells. Reduction of the Bcl-2(lo) mature T-cell subsets was at least 100-fold greater than that of the Bcl-2(hi) subsets. CD4(+) NKT cells upregulated Bcl-2 after TBI and TLI and developed a Th2 bias after TLI, whereas non-NKT cells failed to do so. Our previous studies showed TLI protects against graft versus host disease in wild-type, but not in NKT-cell-deficient mice. The present study shows that NKT cells have a protective function even after TBI, and these cells are tenfold more abundant after an equal dose of TLI. In conclusion, differential expression of Bcl-2 contributes to the changes in T-cell subsets and immune function after irradiation.
PMID: 19197937 [PubMed - indexed for MEDLINE
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19) J Endourol. 2009 Feb;23(2):197-201.
Fibered confocal microscopy of bladder tumors: an ex vivo study.
Sonn GA, Mach KE, Jensen K, Hsiung PL, Jones SN, Contag CH, Wang TD, Liao JC.
Department of Urology, Stanford University School of Medicine, Stanford, California 94305-5118, USA.
BACKGROUND AND PURPOSE: The inadequacy of white-light cystoscopy to detect flat bladder tumors is well recognized. Great interest exists in developing other imaging technologies to augment or supplant conventional cystoscopy. Fibered confocal microscopy offers the promise of providing in vivo histopathologic information to help distinguish malignant from benign bladder lesions. We report the initial use of this technology to visualize tumors in the human bladder. MATERIALS AND METHODS: We performed ex vivo fibered confocal imaging of fresh radical cystectomy specimens using the Mauna Kea Technologies Cellvizio system. The findings were compared with results from standard histopathology. RESULTS: The bladders of four patients were imaged using the fibered confocal microscope. Normal and neoplastic urothelium manifested differences in cellular and vascular density. CONCLUSION: This study demonstrates the feasibility of using fibered confocal microscopy to detect histologic differences between normal and neoplastic urothelium, and establishes a foundation for the use of fiber-based confocal microscopy in clinical studies. PMID: 19196063 [PubMed - indexed for MEDLINE
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20) Nature. 2009 Apr 9;458(7239):780-3.
Association of reactive oxygen species levels and radioresistance in cancer stem cells
.Diehn M, Cho RW, Lobo NA, Kalisky T, Dorie MJ, Kulp AN, Qian D, Lam JS, Ailles LE, Wong M, Joshua B, Kaplan MJ, Wapnir I, Dirbas FM, Somlo G, Garberoglio C, Paz B, Shen J, Lau SK, Quake SR, Brown JM, Weissman IL, Clarke MF.
Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305, USA.
The metabolism of oxygen, although central to life, produces reactive oxygen species (ROS) that have been implicated in processes as diverse as cancer, cardiovascular disease and ageing. It has recently been shown that central nervous system stem cells and haematopoietic stem cells and early progenitors contain lower levels of ROS than their more mature progeny, and that these differences are critical for maintaining stem cell function. We proposed that epithelial tissue stem cells and their cancer stem cell (CSC) counterparts may also share this property. Here we show that normal mammary epithelial stem cells contain lower concentrations of ROS than their more mature progeny cells. Notably, subsets of CSCs in some human and murine breast tumours contain lower ROS levels than corresponding non-tumorigenic cells (NTCs). Consistent with ROS being critical mediators of ionizing-radiation-induced cell killing, CSCs in these tumours develop less DNA damage and are preferentially spared after irradiation compared to NTCs. Lower ROS levels in CSCs are associated with increased expression of free radical scavenging systems. Pharmacological depletion of ROS scavengers in CSCs markedly decreases their clonogenicity and results in radiosensitization. These results indicate that, similar to normal tissue stem cells, subsets of CSCs in some tumours contain lower ROS levels and enhanced ROS defences compared to their non-tumorigenic progeny, which may contribute to tumour radioresistance. PMID: 19194462 [PubMed - indexed for MEDLINE
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21) J Virol. 2009 Apr;83(8):3904-18. Epub 2009 Feb 4.
The replication cycle of varicella-zoster virus: analysis of the kinetics of viral protein expression, genome synthesis, and virion assembly at the single-cell level.
Reichelt M, Brady J, Arvin AM.
Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Dr., Grant Bldg., Room S356, Stanford, CA 94305, USA. reichelt@stanford.edu
Varicella-zoster virus (VZV) is a human alphaherpesvirus that is highly cell associated in cell culture. Because cell-free virus yields are too low to permit the synchronous infections needed for time-resolved analyses, information is lacking about the sequence of events during the VZV replication cycle. To address this challenge, we differentially labeled VZV-infected inoculum cells (input) and uninfected (output) cells with fluorescent cell dyes or endocytosed nanogold particles and evaluated newly infected cells by confocal immunofluorescence or electron microscopy (EM) at the single-cell level at defined intervals. We demonstrated the spatiotemporal expression of six major VZV proteins, ORF61, IE62, IE63, ORF29, ORF23, and gE, representing all putative kinetic classes, for the first time. Newly synthesized ORF61, as well as IE62, the major VZV transactivator, appeared within 1 h, and they were targeted to different subnuclear compartments. The formation of VZV DNA replication compartments started between 4 and 6 h, involved recruitment of ORF29 to putative IE62 prereplication sites, and resulted in large globular nuclear compartments where newly synthesized viral DNA accumulated. Although considered a late protein, gE accumulated in the Golgi compartment at as early as 4 h. ORF23 capsid protein was present at 9 h. The assembly of viral nucleocapsids and mature enveloped VZ virions was detected by 9 to 12 h by time-resolved EM. Although syncytium formation is a hallmark of VZV infection, infection of neighboring cells did not require cell-cell fusion; its occurrence from 9 h is likely to amplify VZV replication. Our results define the productive cycle of VZV infection in a single cell as occurring in 9 to 12 h. PMID: 19193797 [PubMed - indexed for MEDLINE]
PMCID: PMC2663235 [Available on 2009/10/01
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22) J Comput Biol. 2009 Feb;16(2):201-12.
Learning signaling network structures with sparsely distributed data.
Sachs K, Itani S, Carlisle J, Nolan GP, Pe'er D, Lauffenburger DA.
Department of Microbiology and Immunology, Baxter Laboratory in Genetic Pharmacology, Stanford University School of Medicine, Stanford, CA, USA.
Flow cytometric measurement of signaling protein abundances has proved particularly useful for elucidation of signaling pathway structure. The single cell nature of the data ensures a very large dataset size, providing a statistically robust dataset for structure learning. Moreover, the approach is easily scaled to many conditions in high throughput. However, the technology suffers from a dimensionality constraint: at the cutting edge, only about 12 protein species can be measured per cell, far from sufficient for most signaling pathways. Because the structure learning algorithm (in practice) requires that all variables be measured together simultaneously, this restricts structure learning to the number of variables that constitute the flow cytometer's upper dimensionality limit. To address this problem, we present here an algorithm that enables structure learning for sparsely distributed data, allowing structure learning beyond the measurement technology's upper dimensionality limit for simultaneously measurable variables. The algorithm assesses pairwise (or n-wise) dependencies, constructs "Markov neighborhoods" for each variable based on these dependencies, measures each variable in the context of its neighborhood, and performs structure learning using a constrained search.
PMID: 19193145 [PubMed - indexed for MEDLINE
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23) J Allergy Clin Immunol. 2009 Apr;123(4):933-9.e10. Epub 2009 Jan 18.
Selective deregulation in chemokine signaling pathways of CD4+CD25(hi)CD127(lo)/(-) regulatory T cells in human allergic asthma.
Nguyen KD, Vanichsarn C, Fohner A, Nadeau KC.
Department of Pediatrics, Stanford University, Stanford, CA 94305, USA.
BACKGROUND: CD4+CD25(hi)CD127(lo)/(-) regulatory T cells have been suggested to be critical regulators of inflammatory processes in allergic asthma. Recent studies reported a selective decrease in the frequency of regulatory T cells in the bronchoalveolar lavage fluid of allergic asthmatic (AA) subjects, prompting the possibility of defective recruitment of these cells to the airway in response to chemokines produced during asthmatic inflammation. OBJECTIVES: This study aimed to characterize the chemotactic profile of circulating regulatory T cells in AA subjects in response to chemokines abundantly produced in airway inflammation, such as CCL1, CCL17, and CCL22. METHODS: The study was performed in a cohort of 26 AA, 16 healthy control, and 16 non-AA subjects. We used chemotaxis assays to evaluate cell migration, flow cytometry to examine chemokine receptor expression, and phospho-ELISA to study consequent signaling pathways in regulatory T cells. RESULTS: Regulatory T cells, but not CD4+CD25(-)T cells, from AA subjects showed decreased chemotactic responses, specifically to CCL1, in comparison with their healthy control and non-AA counterparts. Decreased CCL1-mediated chemotaxis in AA regulatory T cells was associated with decreased phosphorylation of protein kinase B (AKT), a protein involved in chemokine intracellular signaling. Furthermore, the decreased chemotactic response to CCL1 in AA regulatory T cells significantly correlated with asthma severity and decreased pulmonary function in AA subjects. CONCLUSIONS: These results provide the first evidence of dysfunction in the chemokine signaling pathway in AA regulatory T cells. PMID: 19152963 [PubMed - indexed for MEDLINE
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24) Arch Neurol. 2009 Feb;66(2):161-5. Epub 2008 Dec 8.
Blood protein signature for the early diagnosis of Alzheimer disease.
Britschgi M, Wyss-Coray T.
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305-5235, USA.
Alzheimer disease (AD) has become one of the main health concerns for the elderly population in the United States. Current treatments target symptoms only, but several advanced clinical trials are testing new drugs that are potentially disease modifying. Because AD is still difficult to diagnose in its earliest stages and the disease process is estimated to start many years before current clinical diagnosis is made, accurate and simple diagnostic tools are urgently needed. We recently described a blood-based panel of secreted signaling proteins that distinguishes between blinded samples from patients with AD and control subjects with high accuracy. The same proteins also predicted progression to AD in preclinical patients with mild cognitive impairment several years before clinical diagnosis for AD was made. Herein, we describe these findings and discuss the potential for a more general application of our proteomic approach in understanding and diagnosing disease. PMID: 19064741 [PubMed - indexed for MEDLINE
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25) Semin Immunol. 2008 Dec;20(6):311-6.
The genetic and evolutionary balances in human NK cell receptor diversity.
Parham P.
Department of Structural Biology, Stanford University School of Medicine, 299 Campus Drive West, Stanford, CA 94305, USA. peropa@stanford.edu
In primates and cattle two ancient killer-cell immunoglobulin-like receptor (KIR) lineages independently evolved to become diverse NK cell receptors. In mice, KIR genes were sidelined to the X chromosome, a possible consequence of pathogen-mediated selection on the receptor for IgA-Fc. In humans, KIR uniquely form two omnipresent haplotype groups (A and B), postulated here to play complementary and necessary roles in immune defense and reproduction. The basis of KIR3DL1/S1 polymorphism is three ancient lineages maintained by long-term balancing selection and present in all human populations. Conserved and variable NK cell receptors produce structurally diverse NK cell receptor repertoires within a defined range of missing-self-response. PMID: 19036608 [PubMed - indexed for MEDLINE]
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26) J Vasc Interv Radiol. 2009 Feb;20(2):235-9. Epub 2008 Nov 18.
Safety and efficacy of percutaneous fiducial marker implantation for image-guided radiation therapy.
Kothary N, Heit JJ, Louie JD, Kuo WT, Loo BW Jr, Koong A, Chang DT, Hovsepian D, Sze DY, Hofmann LV.
Division of Interventional Radiology, Stanford University Medical Center, 300 Pasteur Dr, H3652, Stanford, CA 94305-5642, USA. kothary@stanford.edu
PURPOSE: To evaluate the safety and technical success rate of percutaneous fiducial marker implantation in preparation for image-guided radiation therapy. MATERIALS AND METHODS: From January 2003 to January 2008, we retrospectively reviewed 139 percutaneous fiducial marker implantations in 132 patients. Of the 139 implantations, 44 were in the lung, 61 were in the pancreas, and 34 were in the liver. Procedure-related major and minor complications were documented. Technical success was defined as implantation enabling adequate treatment planning and computed tomographic simulation. RESULTS: The major and minor complication rates were 5% and 17.3%, respectively. Pneumothorax after lung implantation was the most common complication. Pneumothoraces were seen in 20 of the 44 lung implantations (45%); a chest tube was required in only seven of the 44 lung transplantations (16%). Of the 139 implantations, 133 were successful; in six implantations (4.3%) the fiducial markers migrated and required additional procedures or alternate methods of implantation. CONCLUSIONS: Percutaneous implantation of fiducial marker is a safe and effective procedure with risks that are similar to those of conventional percutaneous organ biopsy.
PMID: 19019700 [PubMed - indexed for MEDLINE
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27) Pediatr Transplant. 2008 Dec;12(8):835-46.
Combined liver-kidney transplantation in children: indications and outcome.
Sutherland SM, Alexander SR, Sarwal MM, Berquist WE, Concepcion W.
Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA. suthersm@stanford.edu
Although it remains a relatively infrequent procedure in children, CLKT has become a viable option for a select group of pediatric patients with severe liver and kidney disease. Most are performed for rare primary diseases such as PH1, but a selected few are performed in the setting of concomitant hepatic and renal failure of uncertain etiology and prognosis. This article reviews the indications for and outcomes following CLKT in children. While it focuses on the specific primary diseases which impact liver and kidney function simultaneously, it addresses the indications based on concomitant hepatic and renal failure, such as seen in the hepatorenal syndrome, as well. PMID: 19000066 [PubMed - indexed for MEDLINE]
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28) Biomed Mater. 2009 Feb;4(1):11001. Epub 2008 Nov 4.
Viral infection of human progenitor and liver-derived cells encapsulated in three-dimensional PEG-based hydrogel.
Cho NJ, Elazar M, Xiong A, Lee W, Chiao E, Baker J, Frank CW, Glenn JS.
Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, CCSR Building Room 3115A, 269 Campus Drive, Stanford, CA 94305, USA.
We have studied the encapsulation of human progenitor cells into 3D PEG hydrogels. Replication-incompetent lentivirus promoter reporter vectors were found to efficiently detect the in vivo expression of human hepatic genes in hydrogel-encapsulated liver progenitor cells. Similarly, hydrogel-encapsulated cells could be efficiently infected with hepatitis C virus, and progeny infectious virus could be recovered from the media supernatants of the hydrogels. Provocatively, the diameters of these virus particles range from approximately 50 to 100 nm, while the calculated mesh size of the 8 k hydrogel is 44.6 +/- 1.7 A. To reconcile how viral particles can penetrate the hydrogels to infect the encapsulated cells, we propose that microfractures/defects of the hydrogel result in a functional pore size of up to 20 fold greater than predicted by theoretical mesh calculations. These results suggest a new model of hydrogel structure, and have exciting implications for tissue engineering and hepatitis virus studies.
PMID: 18981544 [PubMed - indexed for MEDLINE
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29) J Neurol Sci. 2008 Nov 15;274(1-2):1-4. Epub 2008 Sep 3.
New targets for treatment of multiple sclerosis.
Steinman L.
Department of Neurology and Neurological Sciences, Interdepartmental Program in Immunology, Stanford University, Stanford CA 94305, United States. Steinman@stanford.edu
By studying gene transcripts in active lesions of multiple sclerosis via robotic sequencing and gene chips, as well as studying the very same tissue via proteomics, we have discovered several targets at the tipping points in pathophysiologic pathways controlling relapse and remission in multiple sclerosis. In this Charcot Lecture, I shall focus on osteopontin-the binding partner for alpha4 beta 1 integrin, on alpha B crystallin and on two members of the coagulation cascade tissue factor and the inhibitor of protein C. These four proteins are critical in controlling relapse and remission in MS. PMID: 18768188 [PubMed - indexed for MEDLINE]
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30) Bioorg Med Chem. 2009 Feb 1;17(3):1071-8. Epub 2008 Mar 2.
Evaluation of alpha,beta-unsaturated ketone-based probes for papain-family cysteine proteases.
Yang Z, Fonovic M, Verhelst SH, Blum G, Bogyo M.
Department of Pathology, Stanford School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.
The field of activity-based proteomics makes use of small molecule active site probes to monitor distinct subsets of enzymatic proteins. While a number of reactive functional groups have been applied to activity-based probes (ABPs) that target diverse families of proteases, there remains a continual need for further evaluation of new probe scaffolds and reactive functional groups for use in ABPs. In this study we evaluate the utility of the, alpha,beta-unsaturated ketone reactive group for use in ABPs targeting the papain-family of cysteine proteases. We find that this reactive group shows highly selective labeling of cysteine cathepsins in both intact cells and total cell extracts. We observed a variable degree of background labeling that depended on the type of tag and linker used in the probe synthesis. The relative ease of synthesis of this class of compounds provides the potential for further derivatization to generate new families of cysteine protease ABPs with unique specificity and labeling properties.
PMID: 18343672 [PubMed - indexed for MEDLINE]
PMCID: PMC2659416 [Available on 2010/02/01]
31) Clin J Am Soc Nephrol. 2009 Apr 30. [Epub ahead of print]
Nonrecovery of Kidney Function and Death after Acute on Chronic Renal Failure.
Hsu CY, Chertow GM, McCulloch CE, Fan D, Ordoñez JD, Go AS.
Departments of Medicine and Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, Department of Medicine, Stanford University, Stanford, and Divisions of Research and ||Nephrology, Kaiser Permanente of Northern California Oakland Medical Center, Oakland, California.
BACKGROUND AND OBJECTIVES: Relatively little is known about clinical outcomes, especially long-term outcomes, among patients who have chronic kidney disease (CKD) and experience superimposed acute renal failure (ARF; acute on chronic renal failure). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We tracked 39,805 members of an integrated health care delivery system in northern California who were hospitalized during 1996 through 2003 and had prehospitalization estimated GFR (eGFR) <45 ml/min per 1.73 m(2). Superimposed ARF was defined as having both a peak inpatient serum creatinine greater than the last outpatient serum creatinine by >/=50% and receipt of acute dialysis. RESULTS: Overall, 26% of CKD patients who suffered superimposed ARF died during the index hospitalization. There was a high risk for developing ESRD within 30 d of hospital discharge that varied with preadmission renal function, being 42% among hospital survivors with baseline eGFR 30-44 ml/min per 1.73 m(2) and 63% among hospital survivors with baseline eGFR 15-29 ml/min per 1.73 m(2). Compared with patients who had CKD and did not experience superimposed ARF, those who did had a 30% higher long-term risk for death or ESRD. CONCLUSIONS: In a large, community-based cohort of patients with CKD, an episode of superimposed dialysis-requiring ARF was associated with very high risk for nonrecovery of renal function. Dialysis-requiring ARF also seemed to be an independent risk factor for long-term risk for death or ESRD.
PMID: 19406959 [PubMed - as supplied by publisher
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32) J Vis Exp. 2009 Jan 14;(23). pii: 1092. doi: 10.3791/1092.
Determining heat and mechanical pain threshold in inflamed skin of human subjects.
Angst MS, Tingle M, Phillips NG, Carvalho B.
Department of Anesthesia, Stanford University School of Medicine, USA.
In a previous article in the Journal of Visualized Experiments we have demonstrated skin microdialysis techniques for the collection of tissue-specific nociceptive and inflammatory biochemicals in humans. In this article we will show pain-testing paradigms that are often used in tandem with microdialysis procedures. Combining pain tests with microdialysis provides the critical link between behavioral and biochemical data that allows identifying key biochemicals responsible for generating and propagating pain. Two models of evoking pain in inflamed skin of human study participants are shown. The first model evokes pain with aid of heat stimuli. Heat evoked pain as described here is predominantly mediated by small, non-myelinated peripheral nociceptive nerve fibers (C-fibers). The second model evokes pain via punctuated pressure stimuli. Punctuated pressure evoked pain is predominantly mediated by small, myelinated peripheral nociceptive nerve fibers (A-delta fibers). The two models are mechanistically distinct and independently examine nociceptive processing by the two major peripheral nerve fiber populations involved in pain signaling. Heat pain is evoked with aid of the TSA II, a commercially available thermo-sensory analyzer (Medoc Advanced Medical Systems, Durham, NC). Stimulus configuration and delivery is handled with aid of specific software. Thermodes vary in size and shape but in principle consist of a metal plate that can be heated or cooled at various rates and for different periods of time. Algorithms assessing heat-evoked pain are manifold. In the experiments shown here, study participants are asked to indicate at what point they start experiencing pain while the thermode in contact with skin is heated at a predetermined rate starting at a temperature that does not evoke pain. The thermode temperature at which a subject starts experiencing pain constitutes the heat pain threshold. Mechanical pain is evoked with punctuated probes. Such probes are commercially available from several manufacturers (von Frey hairs). However, the accuracy of von Frey hairs has been criticized and many investigators use custom made punctuated pressure probes. In the experiments shown here eight custom-made punctuated probes of different weights are applied in consecutive order, a procedure called up-down algorithm, to identify perceptional deflection points, i.e., a change from feeling no pain to feeling pain or vice versa. The average weight causing a perceptional deflection constitutes the mechanical pain threshold. PMID: 19229176 [PubMed - indexed for MEDLINE]
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33) Pain. 2008 Sep 30;139(1):15-27. Epub 2008 Apr 8.
Cytokine profile in human skin in response to experimental inflammation, noxious stimulation, and administration of a COX-inhibitor: a microdialysis study.
Angst MS, Clark JD, Carvalho B, Tingle M, Schmelz M, Yeomans DC.
Department of Anesthesia, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305-5117, USA. ang@stanford.edu
Animal studies have documented a critical role for cytokines in cell signaling events underlying inflammation and pain associated with tissue injury. While clinical reports indicate an important role of cytokines in inflammatory pain, methodological limitations have made systematic human studies difficult. This study examined the utility of a human in vivo bioassay combining microdialysis with multiplex immunoassay techniques for measuring cytokine arrays in tissue. The first experiment measured cytokines in interstitial fluid collected from non-inflamed and experimentally inflamed skin (UVB). The effects of noxious heat on cytokine release were also assessed. The second experiment examined whether anti-hyperalgesic effects of the COX-inhibitor ibuprofen were associated with decreased tissue levels of the pro-inflammatory cytokines IL-1 beta and IL-6. In the first experiment, inflammation significantly increased IL-1 beta, IL-6, IL-8, IL-10, G-CSF, and MIP-1 beta. Noxious heat but not experimental inflammation significantly increased IL-7 and IL-13. In the second experiment, an oral dose of 400 and 800 mg ibuprofen produced similar anti-hyperalgesic effects suggesting a ceiling effect. Tissue levels of IL-1 beta and IL-6 were not affected after the 400mg dose but decreased significantly (44+/-32% and 38+/-13%) after the 800 mg dose. These results support the utility of explored method for tracking cytokines in human tissue and suggest that anti-hyperalgesic and anti-inflammatory effects of ibuprofen are at least partially dissociated. The data further suggest that high clinical doses of ibuprofen exert anti-inflammatory effects by down-regulating tissue cytokine levels. Explored human bioassay is a promising tool for studying the pathology and pharmacology of inflammatory and chronic pain conditions. PMID: 18396374 [PubMed - indexed for MEDLINE
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34) Can J Anaesth. 2009 Apr 25. [Epub ahead of print]
Obstetric hemorrhage during an exit procedure for severe fetal airway obstruction.
Butwick A, Aleshi P, Yamout I.
Department of Anesthesia (MC:5640), Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA, 94305, USA, ajbut@stanford.edu.
PURPOSE: To report a case of massive obstetric hemorrhage occurring during Cesarean delivery for an ex utero intrapartum treatment (EXIT) procedure. Methods to optimize the anesthetic, obstetric, and perinatal management are discussed. CLINICAL FEATURES: A healthy parturient underwent an urgent EXIT procedure at 32 weeks gestation for a giant fetal neck mass. During the intraoperative period, severe intraoperative hemorrhage occurred from the site of the uterine incision. No evidence of placental bleeding, premature placental separation, or inadequate uterine relaxation was observed during the perioperative period. Placement of a uterine stapling device was unsuccessful in achieving adequate surgical hemostasis. Initial attempts with laryngoscopy and rigid bronchoscopy to secure the fetal airway on placental support were unsuccessful, and early termination of placental support was deemed necessary due to the severity of maternal blood loss. After full delivery of the neonate and termination of placental support, neonatal ventilation with bag-mask ventilation was achieved and successful endotracheal intubation occurred during repeat bronchoscopy. CONCLUSIONS: The risk of obstetric hemorrhage due to uterine relaxation and inadequate surgical hemostasis in patients undergoing EXIT procedures is poorly reported. To reduce adverse maternal and neonatal outcomes, the premature termination of placental support during EXIT procedures may be required in the setting of severe obstetric hemorrhage. PMID: 19396506 [PubMed - as supplied by publisher]
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35) Bone. 2009 Apr 18. [Epub ahead of print]
Substance P stimulates bone marrow stromal cell osteogenic activity, osteoclast differentiation, and resorption activity in vitro.
Wang L, Zhao R, Shi X, Wei T, Halloran BP, Clark DJ, Jacobs CR, Kingery WS.
Physical Medicine and Rehabilitation Service (117), Veterans Affairs Palo Alto Health Care System, 3801 Miranda Ave., Palo Alto, CA 94304, California, USA; Department of Orthopedic Surgery, Stanford University School of Medicine, Stanford, California, USA.
INTRODUCTION: SP is a neuropeptide distributed in the sensory nerve fibers that innervate the medullar tissues of bone, as well as the periosteum. Previously we demonstrated that inhibition of neuropeptide signaling after capsaicin treatment resulted in a loss of bone mass and we hypothesized that SP contributes to bone integrity by stimulating osteogenesis. MATERIALS AND METHODS: Osteoblast precursors (bone marrow stromal cells, BMSCs) and osteoclast precursors (bone marrow macrophages, BMMs) derived from C57BL/6 mice were cultured. Expression of the SP receptor (NK1) was detected by using immunocytochemical staining and PCR. Effects of SP on proliferation and differentiation of BMSCs were studied by measuring BrdU incorporation, gene expression, alkaline phosphatase activity, and osteocalcin and Runx2 protein levels with EIA and western blot assays, respectively. Effects of SP on BMMs were determined using a BrdU assay, counting multinucleated cells staining positive for tartrate-resistant acid phosphatase (TRAP(+)), measuring pit erosion area, and evaluating RANKL protein production and NF-kappaB activity with ELISA and western blot. RESULTS: The NK1 receptor was expressed in both BMSCs and BMMs. SP stimulated the proliferation of BMSCs in a concentration-dependent manner. Low concentrations (10(-12) M) of SP stimulated alkaline phosphatase and osteocalcin expression, increased alkaline phosphatase activity, and up-regulated Runx2 protein levels, and higher concentrations of SP (10(-8) M) enhanced mineralization in differentiated BMSCs. SP also stimulated BMSCs to produce RANKL, but at concentrations too low to evoke osteoclastogenesis in co-culture with macrophages in the presence of SP. SP also activated NF-kappaB in BMMs and directly facilitate RANKL-induced macrophage osteoclastogenesis and bone resorption activity. CONCLUSIONS: NK1 receptors are expressed by osteoblast and osteoclast precursors and SP stimulates osteoblast and osteoclast differentiation and function in vitro. SP neurotransmitter release from sensory neurons could potentially regulate local bone turnover in vivo. PMID: 19379851 [PubMed - as supplied by publisher]
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36) J Virol. 2009 Apr 15. [Epub ahead of print]
Role of microtubules in extracellular release of poliovirus.
Taylor MP, Burgon TB, Kirkegaard K, Jackson WT.
Departments of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA; and Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI.
Cellular autophagy, a process that directs cytosolic contents to the endosomal and lysosomal pathways via the formation of double-membraned vesicles, is a crucial aspect of innate immunity to many intracellular pathogens. However, evidence is accumulating that certain RNA viruses, such as poliovirus, subvert this pathway to facilitate viral growth. The autophagosome-like membranes induced during infection with wild-type poliovirus were found to be, unlike cellular autophagosomes, relatively immobile. Their mobility increased, however, upon nocodazole treatment, arguing that vesicular "tethering" is microtubule-dependent. In cells infected with a mutant virus that is defective in its interaction with the host cytoskeleton and secretory pathway, vesicle movement increased, indicating reduced tethering. In all cases, release of tethering correlated with increased amounts of extracellular virus, consistent with the hypothesis that small amounts of cytosol and virus entrapped by double-membraned structures could be released via fusion with the plasma membrane. We propose that this extracellular delivery of cytoplasmic contents be termed Autophagosome-mediated exit WithOut Lysis (AWOL). This pathway could explain the observed exit, in the apparent absence of cellular lysis, of other cytoplasmic macromolecular complexes, including infectious agents and complexes of aggregated proteins. PMID: 19369338 [PubMed - as supplied by publisher
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37) J Rheumatol. 2009 Apr 15. [Epub ahead of print]
Frequency, Risk, and Cost of Gout-related Episodes Among the Elderly: Does Serum Uric Acid Level Matter?
Wu EQ, Patel PA, Mody RR, Yu AP, Cahill KE, Tang J, Krishnan E.
From the Analysis Group, Inc., Boston, Massachusetts; Takeda Pharmaceuticals North America, Inc., Deerfield, Illinois; and Immunology and Rheumatology, Department of Medicine, Stanford School of Medicine, Stanford, California, USA.
OBJECTIVE: We examined the association between serum uric acid (SUA) level and the frequency, risk, and cost of gout flares among the elderly. METHODS: Data were extracted from the Integrated Healthcare Information Services claims database (1999-2005). Patients were included if they had gout, were aged 65 years and older and had both medical and pharmacy benefits, and electronic laboratory data. Patients with gout and gouty episodes were identified using algorithms based on ICD-9-CM codes and medications. Logistic regression and negative binomial regressions were used to study the relationship between SUA concentration and the annual frequency and one-year risk of gout episodes. Generalized linear models were used to examine the direct healthcare costs associated with gout episodes in the 30 days following each episode. RESULTS: Elderly patients with gout (n = 2237) with high (6-8.99 mg/dl) and very high (> 9 mg/dl) SUA concentrations were more likely to develop a flare within 12 months compared to patients with normal (< 6 mg/dl) SUA levels (OR 2.1, 95% CI 1.7-2.6; OR 3.4, 95% CI 2.6-4.4, respectively). In multivariate regressions, the average annual number of flares increased by 11.9% (p < 0.001) with each unit-increase in SUA level above 6 mg/dl (p < 0.001). Among patients with very high SUA levels, average adjusted total healthcare and gout-related costs per episode were $2,555 and $356 higher, respectively, than those of patients with normal SUA levels (both p < 0.001). CONCLUSION: Higher SUA levels are associated with increased frequency and risk of gout episode, and with higher total and gout-related direct healthcare costs per episode.
PMID: 19369467 [PubMed - as supplied by publisher
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38) Am J Obstet Gynecol. 2009 May;200(5):543.e1-7.
Microfluidic digital PCR enables rapid prenatal diagnosis of fetal aneuploidy.
Fan HC, Blumenfeld YJ, El-Sayed YY, Chueh J, Quake SR.
Department of Bioengineering, Stanford University and Howard Hughes Medical Institute, Stanford, CA, USA.
OBJECTIVE: The purpose of this study was to demonstrate that digital polymerase chain reaction (PCR) enables rapid, allele independent molecular detection of fetal aneuploidy. STUDY DESIGN: Twenty-four amniocentesis and 16 chorionic villus samples were used for microfluidic digital PCR analysis. Three thousand and sixty PCR reactions were performed for each of the target chromosomes (X, Y, 13, 18, and 21), and the number of single molecule amplifications was compared to a reference. The difference between target and reference chromosome counts was used to determine the ploidy of each of the target chromosomes. RESULTS: Digital PCR accurately identified all cases of fetal trisomy (3 cases of trisomy 21, 3 cases of trisomy 18, and 2 cases of triosmy 13) in the 40 specimens analyzed. The remaining specimens were determined to have normal ploidy for the chromosomes tested. CONCLUSION: Microfluidic digital PCR allows detection of fetal chromosomal aneuploidy utilizing uncultured amniocytes and chorionic villus tissue in less than 6 hours. PMID: 19375573 [PubMed - in process
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39) BMC Genomics. 2009 Mar 19;10:116.
Digital PCR provides sensitive and absolute calibration for high throughput sequencing.
White RA 3rd, Blainey PC, Fan HC, Quake SR.
Department of Bioengineering at Stanford University and Howard Hughes Medical Institute, Stanford, CA 94305, USA. raw937@sbcglobal.net
BACKGROUND: Next-generation DNA sequencing on the 454, Solexa, and SOLiD platforms requires absolute calibration of the number of molecules to be sequenced. This requirement has two unfavorable consequences. First, large amounts of sample-typically micrograms-are needed for library preparation, thereby limiting the scope of samples which can be sequenced. For many applications, including metagenomics and the sequencing of ancient, forensic, and clinical samples, the quantity of input DNA can be critically limiting. Second, each library requires a titration sequencing run, thereby increasing the cost and lowering the throughput of sequencing. RESULTS: We demonstrate the use of digital PCR to accurately quantify 454 and Solexa sequencing libraries, enabling the preparation of sequencing libraries from nanogram quantities of input material while eliminating costly and time-consuming titration runs of the sequencer. We successfully sequenced low-nanogram scale bacterial and mammalian DNA samples on the 454 FLX and Solexa DNA sequencing platforms. This study is the first to definitively demonstrate the successful sequencing of picogram quantities of input DNA on the 454 platform, reducing the sample requirement more than 1000-fold without pre-amplification and the associated bias and reduction in library depth. CONCLUSION: The digital PCR assay allows absolute quantification of sequencing libraries, eliminates uncertainties associated with the construction and application of standard curves to PCR-based quantification, and with a coefficient of variation close to 10%, is sufficiently precise to enable direct sequencing without titration runs.
PMID: 19298667 [PubMed - indexed for MEDLINE] PMCID: PMC2667538
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40) Radiology. 2009 Apr 14. [Epub ahead of print]
Imaging Gene Expression in Human Mesenchymal Stem Cells: From Small to Large Animals.
Willmann JK, Paulmurugan R, Rodriguez-Porcel M, Stein W, Brinton TJ, Connolly AJ, Nielsen CH, Lutz AM, Lyons J, Ikeno F, Suzuki Y, Rosenberg J, Chen IY, Wu JC, Yeung AC, Yock P, Robbins RC, Gambhir SS.
Molecular Imaging Program at Stanford, Department of Radiology and Bio-X Program, and Department of Bioengineering, Stanford University School of Medicine, James H. Clark Center, 318 Campus Dr, East Wing, 1st Floor, Stanford, CA 94305-5427.
Purpose: To evaluate the feasibility of reporter gene imaging in implanted human mesenchymal stem cells (MSCs) in porcine myocardium by using clinical positron emission tomography (PET)-computed tomography (CT) scanning. Materials and Methods: Animal protocols were approved by the Institutional Administrative Panel on Laboratory Animal Care. Transduction of human MSCs by using different doses of adenovirus that contained a cytomegalovirus (CMV) promoter driving the mutant herpes simplex virus type 1 thymidine kinase reporter gene (Ad-CMV-HSV1-sr39tk) was characterized in a cell culture. A total of 2.25 x 10(6) transduced (n = 5) and control nontransduced (n = 5) human MSCs were injected into the myocardium of 10 rats, and reporter gene expression in human MSCs was visualized with micro-PET by using the radiotracer 9-(4-[fluorine 18]-fluoro-3-hydroxymethylbutyl)-guanine (FHBG). Different numbers of transduced human MSCs suspended in either phosphate-buffered saline (PBS) (n = 4) or matrigel (n = 5) were injected into the myocardium of nine swine, and gene expression was visualized with a clinical PET-CT. For analysis of cell culture experiments, linear regression analyses combined with a t test were performed. To test differences in radiotracer uptake between injected and remote myocardium in both rats and swine, one-sided paired Wilcoxon tests were performed. In swine experiments, a linear regression of radiotracer uptake ratio on the number of injected transduced human MSCs was performed. Results: In cell culture, there was a viral dose-dependent increase of gene expression and FHBG accumulation in human MSCs. Human MSC viability was 96.7% (multiplicity of infection, 250). Cardiac FHBG uptake in rats was significantly elevated (P < .0001) after human MSC injection (0.0054% injected dose [ID]/g +/- 0.0007 [standard deviation]) compared with that in the remote myocardium (0.0003% ID/g +/- 0.0001). In swine, myocardial radiotracer uptake was not elevated after injection of up to 100 x 10(6) human MSCs (PBS group). In the matrigel group, signal-to-background ratio increased to 1.87 after injection of 100 x 10(6) human MSCs and positively correlated (R(2) = 0.97, P < .001) with the number of administered human MSCs. Conclusion: Reporter gene imaging in human MSCs can be translated to large animals. The study highlights the importance of co-administering a "scaffold" for increasing intramyocardial retention of human MSCs. (c) RSNA, 2009.
PMID: 19366903 [PubMed - as supplied by publisher
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41) Stem Cells Dev. 2009 Mar;18(2):205-14.
Imaging of STAT3 signaling pathway during mouse embryonic stem cell differentiation.
Xie X, Chan KS, Cao F, Huang M, Li Z, Lee A, Weissman IL, Wu JC.
Department of Radiology and Molecular Imaging Program, Division of Cardiology, Stanford University, Stanford, California 94305-5344, USA.
Signal transducers and activators of transcription 3 (STAT3) is a pleiotropic transcription factor involved in a variety of physiological processes. STAT3 acts as a key transcriptional determinant of mouse embryonic stem (ES) cell self-renewal and plays a pivotal function in early mammalian embryogenesis because the development of many organs requires STAT3 activation. However, little is known about the role of STAT3 function during ES cell differentiation. To answer this question, we built a lentiviral construct with 7-repeat STAT3-binding sequence (enhancer) and minimal TA (promoter) driving renilla luciferase and monomeric red fluorescence protein (Rluc-mRFP), followed by a constitutive cytomegalovirus promoter driving green fluorescent protein as a selection marker. The specificity of our custom-designed 7-repeat STAT3 reporter construct was first confirmed by cotransfection with constitutively active version of STAT3 (STAT3C) into human embryonic kidney 293T cells. Next, a mouse ES cell line stably transduced with STAT3 reporter construct was isolated. This ES cell line showed a tight response in reporter gene expression with leukemia inhibitory factor (LIF) induction and was chosen as a developmental model for the STAT3 functional study. Using serial noninvasive bioluminescence imaging, we showed that the onset of embryoid body (EB) formation involved inhibition of STAT3 activity. However, during differentiation, STAT3 activity steadily increased from day 5 to 14 and was reduced by day 21. STAT3 activity was also confirmed separately by Western blots. Finally, phosphorylation of STAT3 was also found to correspond with cardiomyocyte differentiation. In summary, this is the first study to monitor real-time STAT3 activity during ES cell differentiation. This genetically modified line can be used to study the biological role of STAT3 during ES cell differentiation into different derivatives. PMID: 18576943 [PubMed - indexed for MEDLINE
ITI Faculty and Researchers’ Publications for May 2008
Autophagy.2008 May-Jun;4(3):286-9. Epub 2007 Dec 5
Potential subversion of autophagosomal pathway by picornaviruses
Taylor MP, Kirkegaard K.
Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94301, USA.
The RNA replication complexes of small positive-strand RNA viruses such as poliovirus are known to form on the surfaces of membranous vesicles in the cytoplasm of infected mammalian cells. These membranes resemble cellular autophagosomes in their double-membraned morphology, cytoplasmic lumen, lipid-rich composition and the presence of cellular proteins LAMP 1 and LC3. Furthermore, LC3 protein is covalently modified during poliovirus infection in a manner indistinguishable from that observed during bona fide autophagy. This covalent modification can also be induced by the expression of viral protein 2BC in isolation. However, differences between poliovirus-induced vesicles and autophagosomes also exist: the viral-induced membranes are smaller, at 200-400 nm in diameter, and can be induced by the combination of two viral proteins, termed 2BC and 3A. Experimental suppression of expression of proteins in the autophagy pathway was found to reduce viral yield, arguing that this pathway facilitates viral infection, rather than clearing it. We have hypothesized that, in addition to providing membranous surfaces for assembly of viral RNA replication complexes, double-membraned vesicles provide a topological mechanism to deliver cytoplasmic contents, including mature virus, to the extracellular milieu without lysing the cell. PMID: 18094610 [PubMed - in process]
Stem Cells. 2008 Jun 5. [Epub ahead of print]
Isolation and Transcriptional Profiling of Purified Hepatic Cells Derived from Human Embryonic Stem Cells.
Chiao E, Elazar M, Xing Y, Xiong A, Kmet M, Millan MT, Glenn JS, Wong WH, Baker J.
Institute of Stem Cell Biology and Regenerative Medicine, Stanford University, Palo Alto, CA, USA; Department of Genetics, Stanford University School of Medicine, Palo Alto, CA, USA.
The differentiation of human embryonic stem cells (hESCs) into functional hepatocytes provides a powerful in vitro model system for studying the molecular mechanisms governing liver development. Furthermore, a well characterized renewable supply of hepatocytes differentiated from hESCs could be used for in vitro assays of drug metabolism and toxicology, screening of potential antiviral agents, and cell-based therapies to treat liver disease. In this study, we describe a protocol for the differentiation of hESCs toward hepatic cells with complex cellular morphologies. Putative hepatic cells were identified and isolated using a lentiviral vector, containing the alpha-fetoprotein promoter driving eGFP expression (AFP:eGFP). Whole-genome transcriptional profiling was performed on triplicate samples of AFP:eGFP+ and AFP:eGFP- cell populations using the recently released Affymetrix Exon Array ST 1.0. Statistical analysis of the transcriptional profiles demonstrated that the AFP:eGFP+ population is highly enriched for genes characteristic of hepatic cells. These data provide a unique insight into the complex process of hepatocyte differentiation, point to signaling pathways that may be manipulated to more efficiently direct the differentiation of hESCs towards mature hepatocytes and identify molecular markers that may be used for further dissection of hepatic cell differentiation from hESCs.
PMID: 18535157 [PubMed - as supplied by publisher]
Trans Am Clin Climatol Assoc. 2006;117:227-38.
Hepatitis a and B superimposed on chronic liver disease: vaccine-preventable diseases.
Keeffe EB.
Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University School of Medicine, Stanford, California.
A number of studies have demonstrated that the acquisition of hepatitis A or hepatitis B in patients with chronic liver disease is associated with high rates of morbidity and mortality. Superimposition of acute hepatitis A in patients with chronic hepatitis C has been associated with a particularly high mortality rate, and chronic hepatitis B virus coinfection with hepatitis C virus is associated with an accelerated progression of chronic liver disease to cirrhosis, decompensated liver disease and hepatocellular carcinoma. With the availability of vaccines against hepatitis B and hepatitis A since 1981 and 1995, respectively, these are vaccine-preventable diseases. Studies have confirmed that hepatitis A and hepatitis B vaccines are safe and immunogenic in patients with mild to moderate chronic liver disease. However, hepatitis A and B vaccination is less effective in patients with advanced liver disease and after liver transplantation. These observations have led to the recommendation that patients undergo hepatitis A and B vaccination early in the natural history of their chronic liver disease. Vaccination rates are low in clinical practice, and public health and educational programs are needed to overcome barriers to facilitate timely implementation of these recommendations.
PMID: 18528476 [PubMed in process]
Ann N Y Acad Sci. 2008 May;1131:203-5.
Gorham's Disease: An Osseous Disease of Lymphangiogenesis?
Radhakrishnan K, Rockson SG.
Stanford Center for Lymphatic and Venous Disorders, Division of Cardiovascular Medicine, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305.
Gorham's disease, also known as massive osteolysis, Gorham-Stout disease, vanishing bone disease, or, phantom bone disease is a rare disorder of the musculoskeletal system. The disease is characterized by osteolysis in bony segments, with localized proliferation of lymphatic channels. The presence of abundant, leaky systemic lymphatic vessels is often accompanied by chylous ascites. There is no standardized treatment available for Gorham's disease, and its molecular mechanisms remain unclear. Future strategies for understanding Gorham's disease should emphasize its apparent identity as a disease of disordered lymphangiogenesis. Breakthroughs in lymphatic research have identified several lymphangiogenic pathways that may play a relevant role in Gorham's disease.
PMID: 18519972 [PubMed - in process]
Ann N Y Acad Sci. 2008 May;1131:155-84.
The clinical spectrum of lymphatic disease.
Radhakrishnan K, Rockson SG.
Division of Cardiovascular Medicine, Falk Cardiovascular Research Center, Stanford University School of Medicine, Stanford, CA 94306. srockson@cvmed.stanford.edu.
Lymphatic disease is quite prevalent, and often not well clinically characterized. Beyond lymphedema, there is a broad array of human disease that directly or indirectly alters lymphatic structure and function. The symptomatic and objective presentation of these patients can be quite diverse. In this review, we have attempted to provide a systematic overview of the subjective and objective spectrum of lymphatic disease, with consideration of all of the categories of disease that primarily or secondarily impair the functional integrity of the lymphatic system. Lymphedema is discussed, along with chromosomal disorders, lymphangioma, infectious diseases, lymphangioleiomyomatosis, lipedema, heritable genetic disorders, complex vascular malformations, protein-losing enteropathy, and intestinal lymphangiectasia.
PMID: 18519969 [PubMed - in process]
Ann N Y Acad Sci. 2008 May;1131:147-54.
Estimating the population burden of lymphedema.
Rockson SG, Rivera KK.
Stanford Center for Lymphatic and Venous Disorders, Division of Cardiovascular Medicine, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305. srockson@cvmed.stanford.edu.
Lymphedema is a complex, regional edematous state that ensues when lymph transport is insufficient to maintain tissue homeostasis. The disorder is remarkably prevalent, but the population implications of lymphatic dysfunction are not well-studied. Prevalence estimates for lymphedema are relatively high, yet its prevalence is likely underestimated. The ability to estimate the burden of disease poses profound implications for current and future lymphedema patients, but the challenge to correctly surmise the incidence and prevalence of lymphedema is complex and the relevant medical literature is scanty. In the absence of the highly desired, prospectively designed and rigorously performed relevant epidemiologic studies, it is instructive to look at the existing studies of lymphedema disease burden. In the current review, the extant literature is examined in the context of the disease setting in which tissue edema is encountered. Incidence or prevalence estimates are provided or inferred, and, where feasible, the size of the subject population is also identified. It is extremely attractive to contemplate that future approaches will entail formal, prospectively designed studies to objectively quantitate incidence and prevalence statistics for individual categories, as well as for the global lymphedema population.
PMID: 18519968 [PubMed - in process
Ann N Y Acad Sci. 2008 May;1131:50-74.
Animal models for the molecular and mechanistic study of lymphatic biology and disease.
Shin WS, Rockson SG.
Stanford Center for Lymphatic and Venous Disorders, Division of Cardiovascular Medicine, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305. srockson@cvmed.stanford.edu.
The development of animal model systems for the study of the lymphatic system has resulted in an explosion of information regarding the mechanisms governing lymphatic development and the diseases associated with lymphatic dysfunction. Animal studies have led to a new molecular model of embryonic lymphatic vascular development, and have provided insight into the pathophysiology of both inherited and acquired lymphatic insufficiency. It has become apparent, however, that the importance of the lymphatic system to human disease extends, beyond its role in lymphedema, to many other diverse pathologic processes, including, very notably, inflammation and tumor lymphangiogenesis. Here, we have undertaken a systematic review of the models as they relate to molecular and functional characterization of the development, maturation, genetics, heritable and acquired diseases, and neoplastic implications of the lymphatic system. The translation of these advances into therapies for human diseases associated with lymphatic dysfunction will require the continued study of the lymphatic system through robust animal disease models that simulate their human counterparts.
PMID: 18519959 [PubMed - in process]
Ann N Y Acad Sci. 2008 May;1131:ix-x.
Preface the lymphatic continuum revisited.
Rockson SG.
Division of Cardiovascular Medicine, Falk Cardiovascular Research Center, Stanford University School of Medicine, Stanford, CA 94306. srockson@cvmed.stanford.edu.
PMID: 18519954 [PubMed - in process]
Annu Rev Biochem. 2008 Jul 7;77:177-203.
Translation at the Single-Molecule Level.
Marshall RA, Aitken CE, Dorywalska M, Puglisi JD.
Department of Chemistry, Stanford University, Stanford, California 94305; andrew.marshall@stanford.edu , 2Biophysics Program, Stanford University, Stanford, California 94305; caitken@stanford.edu , 3Department of Structural Biology, Stanford University, Stanford, California 94305; magg@stanford.edu , 4Stanford Magnetic Resonance Laboratory, School of Medicine, Stanford University, Stanford, California 94305; email: puglisi@stanford.edu.
Decades of studies have established translation as a multistep, multicomponent process that requires intricate communication to achieve high levels of speed, accuracy, and regulation. A crucial next step in understanding translation is to reveal the functional significance of the large-scale motions implied by static ribosome structures. This requires determining the trajectories, timescales, forces, and biochemical signals that underlie these dynamic conformational changes. Single-molecule methods have emerged as important tools for the characterization of motion in complex systems, including translation. In this review, we chronicle the key discoveries in this nascent field, which have demonstrated the power and promise of single-molecule techniques in the study of translation. PMID: 18518820 [PubMed - as supplied by publisher]
J Neurosurg. 2008 Jun;108(6):1152-61.
Multimodality treatment of posterior fossa arteriovenous malformations.
Kelly ME, Guzman R, Sinclair J, Bell-Stephens TE, Bower R, Hamilton S, Marks MP, Do HM, Chang SD, Adler JR, Levy RP, Steinberg GK.
Departments of Neurosurgery,, 3 Radiology,, 2 Neurology and Neurological Sciences, and Stanford Stroke Center, Stanford University School of Medicine, Stanford; and, 4 Department of Radiation Oncology, Loma Linda University, Loma Linda, California.
Object Posterior fossa arteriovenous malformations (AVMs) are relatively uncommon and often difficult to treat. The authors present their experience with multimodality treatment of 76 posterior fossa AVMs, with an emphasis on Spetzler-Martin Grades III-V AVMs. Methods Seventy-six patients with posterior fossa AVMs treated with radiosurgery, surgery, and endovascular techniques were analyzed. Results Between 1982 and 2006, 36 patients with cerebellar AVMs, 33 with brainstem AVMs, and 7 with combined cerebellar-brainstem AVMs were treated. Natural history data were calculated for all 76 patients. The risk of hemorrhage from presentation until initial treatment was 8.4% per year, and it was 9.6% per year after treatment and before obliteration. Forty-eight patients had Grades III-V AVMs with a mean follow-up of 4.8 years (range 0.1-18.4 years, median 3.1 years). Fifty-two percent of patients with Grades III-V AVMs had complete obliteration at the last follow-up visit. Three (21.4%) of 14 patients were cured with a single radiosurgery treatment, and 4 (28.6%) of 14 with 1 or 2 radiosurgery treatments. Twenty-one (61.8%) of 34 patients were cured with multimodality treatment. The mean Glasgow Outcome Scale (GOS) score after treatment was 3.8. Multivariate analysis performed in the 48 patients with Grades III-V AVMs showed radiosurgery alone to be a negative predictor of cure (p = 0.0047). Radiosurgery treatment alone was not a positive predictor of excellent clinical outcome (GOS Score 5; p > 0.05). Nine (18.8%) of 48 patients had major neurological complications related to treatment. Conclusions Single-treatment radiosurgery has a low cure rate for posterior fossa Spetzler-Martin Grades III-V AVMs. Multimodality therapy nearly tripled this cure rate, with an acceptable risk of complications and excellent or good clinical outcomes in 81% of patients. Radiosurgery alone should be used for intrinsic brainstem AVMs, and multimodality treatment should be considered for all other posterior fossa AVMs.
PMID: 18518720 [PubMed - in process]
Cell Res. 2008 Jun;18(6):605-8.
The aryl hydrocarbon receptor: a regulator of Th17 and Treg cell development in disease.
Ho PP, Steinman L.
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.
PMID: 18516065 [PubMed - in process]
Arthritis Rheum. 2008 May 31;58(6):1619-1629. [Epub ahead of print]
Cytokines secreted in response to Toll-like receptor ligand stimulation modulate differentiation of human Th17 cells.
Kattah MG, Wong MT, Yocum MD, Utz PJ.
Stanford University School of Medicine, Stanford, California.
OBJECTIVE: Th17 cells (interleukin-17 [IL-17]-secreting T helper cells) have been implicated in the pathogenesis of rheumatoid arthritis and other autoimmune diseases, but the soluble factors that influence human Th17 differentiation have yet to be fully elucidated. This study was undertaken to investigate the hypothesis that the cytokines secreted by human peripheral blood mononuclear cells (PBMCs) in response to a subset of Toll-like receptor (TLR) ligands would influence Th17 polarization. METHODS: Supernatants from human PBMCs treated with a panel of TLR agonists were tested for their ability to induce de novo IL-17 production in naive T helper cells. Multiplex cytokine analysis was used to identify candidate cytokines for subsequent blocking and sufficiency experiments. RESULTS: Conditioned media from PBMCs stimulated with TLR-4 or TLR-8/7 agonists, but not from those stimulated with TLR-2/1, -3, or -9 agonists, evoked robust secretion of IL-17 by T helper cells, independent of coculture with antigen-presenting cells. Multiplex analysis of 22 cytokines and chemokines identified a 6-factor cytokine signature that significantly correlated with IL-17-inducing activity. T cell activation in the presence of recombinant IL-1beta, IL-6, and IL-23 reconstituted robust IL-17 production, and this was enhanced by transforming growth factor beta (TGFbeta). IL-6 suppressed the expression of forkhead box P3 and reversed TGFbeta-mediated inhibition of T cell proliferation, but did not trigger IL-17 secretion. IL-17 production was completely abrogated by anti-IL-1 or IL-1 receptor antagonist and partially inhibited by anti-IL-6, anti-IL-2, or exogenous retinoic acid, but not by anti-tumor necrosis factor alpha. IL-1beta and IL-6 independently induced IL-21 secretion, but the presence of IL-21 alone was not sufficient for IL-17 production. CONCLUSION: These results indicate that ligation of a subset of TLRs generates proinflammatory cytokines that combine to potentiate human Th17 differentiation. PMID: 18512782 [PubMed - as supplied by publisher]
Arthritis Rheum. 2008 May 30;59(6):760-761. [Epub ahead of print]
What we talk about when we talk about contraception.
Chakravarty EF.
Stanford University School of Medicine, Palo Alto, California.
PMID: 18512709 [PubMed - as supplied by publisher]
Nucleic Acids Res. 2008 May 29. [Epub ahead of print]
Single-molecule imaging of full protein synthesis by immobilized ribosomes.
Uemura S, Iizuka R, Ueno T, Shimizu Y, Taguchi H, Ueda T, Puglisi JD, Funatsu T.
Laboratory of Bio-Analytical Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, 4-1-8, Honcho, Kawaguchi, Saitama 332-0012, Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa-shi, Chiba, 277-8562, Japan, Department of Structural Biology, Stanford University School of Medicine, USA 299 Campus Drive West, Stanford, CA 94305-5126, USA and Center for NanoBio Integration, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
How folding of proteins is coupled to their synthesis remains poorly understood. Here, we apply single-molecule fluorescence imaging to full protein synthesis in vitro. Ribosomes were specifically immobilized onto glass surfaces and synthesis of green fluorescent protein (GFP) was achieved using modified commercial Protein Synthesis using Recombinant Elements that lacked ribosomes but contained purified factors and enzyme that are required for translation in Escherichia coli. Translation was monitored using a GFP mutant (F64L/S65T/F99S/M153T/V163A) that has a high fluorophore maturation rate and that contained the Secretion Monitor arrest sequence to prevent dissociation from the ribosome. Immobilized ribosomal subunits were labeled with Cy3 and GFP synthesis was measured by colocalization of GFP fluorescence with the ribosome position. The rate of appearance of colocalized ribosome GFP was equivalent to the rates of fluorescence appearance coupled with translation measured in bulk, and the ribosome-polypeptide complexes were stable for hours. The methods presented here are applicable to single-molecule investigation of translational initiation, elongation and cotranslational folding. PMID: 18511463 [PubMed - as supplied by publisher]
Blood. 2008 May 28. [Epub ahead of print]
Heme oxygenase-1 deficiency leads to disrupted response to acute stress in stem cells and progenitors.
Cao YA, Wagers AJ, Karsunky H, Zhao H, Reeves R, Wong RJ, Stevenson DK, Weissman IL, Contag CH.
Pediatrics, Stanford University, Palo Alto, CA, United States.
An effective response to extreme hematopoietic stress requires an extreme elevation in hematopoiesis and preservation of hematopoietic stem cells (HSCs). These diametrically opposed processes are likely regulated by genes that mediate cellular adaptation to physiologic stress. Here we show heme oxygenase-1 (HO-1), the inducible isozyme of heme degradation, is a key regulator of these processes. Mice lacking one allele of HO-1 (HO-1(+/-)) showed accelerated hematopoietic recovery from myelotoxic injury, and HO-1(+/-) HSCs repopulated lethally-irradiated recipients with more rapid kinetics. However, HO-1(+/-) HSCs were ineffective in radioprotection and serial repopulation of myeloablated recipients. Perturbations in key stem cell regulators were observed in HO-1(+/-) HSCs and hematopoietic progenitors (HPCs), which may explain the disrupted response of HO-1(+/-) HPCs and HPCs to acute stress. Control of stem cell stress response by HO-1 presents opportunities for metabolic manipulation of stem cell-based therapies. PMID: 18509090 [PubMed - as supplied by publisher]
Clin Chem. 2008 Jun;54(6):937-9.
Protein microarrays address the elephant in the room.
Kattah MG, Utz PJ, Balboni I.
Department of Medicine, Division of Immunology and Rheumatology, Stanford University, Stanford, CA.
PMID: 18509011 [PubMed - in process]
J Infect Dis. 2008 May 23. [Epub ahead of print]
A Possible Mechanism for Synergy between Antifungal Therapy and Immune Defenses.
Stevens DA.
Division of Infectious Diseases, Department of Medicine, Santa Clara Valley Medical Center, and California Institute for Medical Research, San Jose, and Department of Medicine, Stanford University School of Medicine, Stanford, California.
PMID: 18500932 [PubMed - as supplied by publisher]
J Clin Invest. 2008 Jun 2;118(6):2190-2199.
The autophagy-related protein beclin 1 shows reduced expression in early Alzheimer disease and regulates amyloid beta accumulation in mice.
Pickford F, Masliah E, Britschgi M, Lucin K, Narasimhan R, Jaeger PA, Small S, Spencer B, Rockenstein E, Levine B, Wyss-Coray T.
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California, USA. Department of Neurosciences and Pathology, UCSD, La Jolla, California, USA. Institut fuer Chemie und Biochemie, Freie Universitaet Berlin, Berlin, Germany. Columbia University College of Physicians and Surgeons, New York, New York, USA. Division of Infectious Diseases, University of Texas Southwestern Medical Center, Dallas, Texas, USA. Geriatric Research Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California, USA.
Autophagy is the principal cellular pathway for degradation of long-lived proteins and organelles and regulates cell fate in response to stress. Recently, autophagy has been implicated in neurodegeneration, but whether it is detrimental or protective remains unclear. Here we report that beclin 1, a protein with a key role in autophagy, was decreased in affected brain regions of patients with Alzheimer disease (AD) early in the disease process. Heterozygous deletion of beclin 1 (Becn1) in mice decreased neuronal autophagy and resulted in neurodegeneration and disruption of lysosomes. In transgenic mice that express human amyloid precursor protein (APP), a model for AD, genetic reduction of Becn1 expression increased intraneuronal amyloid beta (Abeta) accumulation, extracellular Abeta deposition, and neurodegeneration and caused microglial changes and profound neuronal ultrastructural abnormalities. Administration of a lentiviral vector expressing beclin 1 reduced both intracellular and extracellular amyloid pathology in APP transgenic mice. We conclude that beclin 1 deficiency disrupts neuronal autophagy, modulates APP metabolism, and promotes neurodegeneration in mice and that increasing beclin 1 levels may have therapeutic potential in AD.
PMID: 18497889 [PubMed - as supplied by publisher]
J Virol. 2008 May 21. [Epub ahead of print]
The role of interferon in homologous and heterologous rotavirus infection in the intestines and extra-intestinal organs of suckling mice.
Feng N, Kim B, Fenaux M, Nguyen H, Vo P, Omary B, Greenberg HB.
Stanford University, Stanford, CA; Palo Alto VA Health Care System. Palo Alto, CA; College of Veterinary Medicine, Chonbuk National University, Chonju 561-756, Korea.
Recent studies demonstrated that viremia and extra-intestinal rotavirus infection are common in acutely infected humans and animals while systemic diseases appear to be rare. IP infection of newborn mice with a simian rotavirus (RRV) results in biliary atresia (BA) and this condition is influenced by the host interferon response. We studied orally inoculated 5 days old suckling mice that were deficient in interferon signaling to evaluate the role of interferon on the outcome of local and systemic infection after enteric inoculation. We found that systemic replication of RRV, but not murine rotavirus strain EC, was greatly enhanced in IFNalpha/beta and gamma receptor double KO or STAT1 KO mice but not in mice deficient in B or T cell immunity. The enhanced replication of RRV was associated with a lethal hepatitis, pancreatitis, and BA while no systemic disease was observed in EC infected interferon deficient mice. In IFNalpha/beta receptor KO mice the extra-intestinal infection and systemic disease was only moderately increased while RRV infection was not augmented and systemic disease was not present in IFNgamma receptor KO mice. The increase of systemic infection in IFN deficient mice was also observed during simian SA11 infection but not following bovine NCDV, porcine OSU or murine strain EW infection. Our data indicate that the requirement for the interferon system to inhibit intestinal and extra-intestinal viral replication in suckling mice varies among different heterologous and homologous rotavirus strains and this variation is associated with lethal systemic disease.
PMID: 18495762 [PubMed - as supplied by publisher]
ppl Environ Microbiol. 2008 May 16. [Epub ahead of print]
Leucobacter chromiireducens subsp. solipictus Exerts Virulence on Caenorhabditis elegans, Characterization of a Novel Host-Pathogen Interaction.
Muir RE, Tan MW.
Department of Genetics, Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA.
We describe the pathogenic interaction between a newly described Gram-positive bacterium Leucobacter chromiireducens subsp. solipictus strain TAN 31504 and the nematode Caenorhabditis elegans. TAN 31504 pathogenesis on C. elegans is exerted primarily through infection of the adult nematode uterus. TAN 31504 enters the uterus through the external vulval opening and the ensuing uterine infection is strongly correlated with a significant reduction in host life span. Young worms can fed and develop on TAN 31504, but not preferably over the standard food source. C. elegans reared on TAN 31504 as the sole food source develop into thin adults with little intestinal fat stores, produce few progeny, and subsequently can not persist on the pathogenic food source. Within 12 h of exposure, adult worms challenged with TAN 31504 alter the expression of a number of C. elegans innate immunity-related genes, including nlp-29, which encodes a neuropeptide-like protein. C. elegans exposed briefly to TAN 31504 develop lethal uterine infections analogous to worms exposed continuously to pathogen, suggesting that mere contact with the pathogen is sufficient for the host to become infected. TAN 31504 produces a robust biofilm and this behavior is speculated to play a role in the virulence exerted on the nematode host. The interaction between TAN 31504 and C. elegans provides a convenient opportunity to study bacterial virulence on nematode tissues other than the intestine and may allow for the discovery of host innate immunity elicited specifically in response to vulval-uterine infection. PMID: 18487405 [PubMed - as supplied by publisher]
Nat Rev Immunol. 2008 Jun;8(6):478-86.
Immunomodulatory mast cells: negative, as well as positive, regulators of immunity.
Galli SJ, Grimbaldeston M, Tsai M.
Department of Pathology, Stanford University School of Medicine, Stanford, California 94305-5324, USA. sgalli@stanford.edu
Mast cells can promote inflammation and other tissue changes in IgE-associated allergic disorders, as well as in certain innate and adaptive immune responses that are thought to be independent of IgE. However, mast cells can also have anti-inflammatory and immunosuppressive functions. Here, we review the evidence that mast cells can have negative, as well as positive, immunomodulatory roles in vivo, and we propose that mast cells can both enhance and later suppress certain features of an immune response.
PMID: 18483499 [PubMed - in process]
Cancer Epidemiol Biomarkers Prev. 2008 May;17(5):1188-94.
Helicobacter pylori Infection and Development of Pancreatic Cancer.
de Martel C, Llosa AE, Friedmana GD, Vogelman JH, Orentreich N, Stolzenberg-Solomon RZ, Parsonnet J.
Stanford University School of Medicine, 300 Pasteur Road, Stanford, CA 94305. prosper@stanford.edu.
BACKGROUND: Infection with Helicobacter pylori is an established risk factor for gastric cancer. Results from two studies suggest that it may also be a risk factor for pancreatic cancer. METHODS: We conducted a nested case control study among 128,992 adult subscribers to the Kaiser Permanente Medical Care Program who had been enrolled in a multiphasic health checkup from 1964 to 1969. Serum collected during the checkup was maintained frozen, and subjects were followed for cancer. Cases consisted of 104 randomly selected subjects among 507 who developed pancreatic cancer in the cohort. Controls consisted of 262 pancreatic cancer-free subjects from a pool of 730 controls previously tested for studies conducted on this cohort. Controls were individually matched to cases on age, gender, race, site, and date of multiphasic health checkup. Control sera were compared with cases for antibodies to H. pylori and the CagA protein. The effects of smoking, alcohol consumption, obesity, and years of education were also investigated. RESULTS: Neither H. pylori [odds ratio (OR), 0.85; 95% confidence interval (95% CI), 0.49-1.48] nor its CagA protein (OR, 0.96; 95% CI, 0.48-1.92) was associated with subsequent development of pancreatic cancer. Smoking (OR, 2.09; 95% CI, 1.17-3.74) and greater number of years of education (OR, 2.13; 95% CI, 1.23-3.69) were risk factors for pancreatic cancer, whereas alcohol consumption and obesity were not. CONCLUSION: Our results suggest that H. pylori infection is not associated with development of pancreatic cancer. (Cancer Epidemiol Biomarkers Prev 2008;17(5):1188-94).
PMID: 18483341 [PubMed - in process]
Immunity. 2008 May;28(5):600-2.
Type 1 interferons cool the inflamed brain.
Axtell RC, Steinman L.
Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA.
Although interferon-beta is the most popular treatment for multiple sclerosis, its mechanism of action remains enigmatic. In this issue of Immunity, Prinz et al. (2008) elucidate an intriguing portrait of the pleiotropic effects of type 1 interferons in taming brain inflammation.
PMID: 18482563 [PubMed - in process]
Immunother. 2008 Feb-Mar;31(2):207-14.
CA125 velocity at relapse is a highly significant predictor of survival post relapse: results of a 5-year follow-up survey to a randomized placebo-controlled study of maintenance oregovomab immunotherapy in advanced ovarian cancer.
Berek JS, Taylor PT, Nicodemus CF.
Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, Stanford University School of Medicine, Stanford Cancer Center, Stanford, CA, USA. jberek@stanford.edu
This report presents final survival survey results from a previously reported study using oregovomab immunotherapy in patients with advanced ovarian epithelial cancer. Follow-up surveys to 5 years from randomization were collected for the cohort of stage III/IV ovarian cancer patients achieving initial remission who received subsequent maintenance immunotherapy with oregovomab or placebo. The relationship of time-to-relapse, survival postrelapse, and overall survival was analyzed. One hundred forty-five patients in the intent-to-treat population and the hypothesis generating subset of 67 patients (debulked to < or =2 cm, CA125 < or =65 U/mL before cycle 3, normal CA125 and no evidence of disease postchemotherapy) previously reported were evaluated for long-term outcomes. Patterns of relapse and survival were consistent in both groups for the intent-to-treat population. Median survival time was 57.5 months for oregovomab and 48.6 months for placebo with an adjusted hazard ratio of 0.72 (95% confidence interval, 0.41-1.25). Median survival has not been reached in the hypothesis generating subset of patients receiving oregovomab. Cox multivariate regression analysis identified velocity of CA125 rise at relapse to be a highly statistically significant predictor of postrelapse outcome (P = 0.006). Although time-to-relapse may be a useful surrogate of survival in ovarian cancer immunotherapy studies, 5 years of follow-up has proved insufficient to permit a definitive survival analysis and it has been extended in ongoing phase III studies of oregovomab. Velocity of CA125 rise at relapse is a highly significant predictor of survival after relapse.
PMID: 18481390 [PubMed - in process]
J Virol. 2008 May 14. [Epub ahead of print]
Qualitative and quantitative characteristics of rotavirus-specific CD8 T cells vary depending on the route of infection.
Jiang JQ, He XS, Feng N, Greenberg HB.
Departments of Medicine and Microbiology, and Immunology, Stanford University School of Medicine, Stanford, CA 94305; and the Veterans Affairs Palo Alto Health Care System, Palo Alto, CA.
CD8 T cell response provides an important defense against rotavirus, which infects a variety of systemic locations in addition to the gut. Here we investigated the distribution, phenotype and function of rotavirus-specific CD8 T cells in multiple organs after rotavirus infection initiated via intranasal, oral or intramuscular routes. The highest level of virus-specific CD8 T cells was observed in the Peyer's patches of orally infected mice and in the lungs of intranasally infected animals. Very low levels of virus-specific CD8 T cells were detected in peripheral blood or spleen following any route of infection. Rotavirus-specific CD8 T cells from Peyer's patch of orally infected mice expressed high levels of CCR9 while CXCR6 and LFA-1 expression was associated with virus-specific CD8 T cells in lung of intranasally infected mice. Oral infection induced the highest proportion of IFN-gamma(-) CD107a/b(+) CD8 T cells in Peyer's patch. When equal numbers of rotavirus-specific CD8 T cells were transferred into Rag-1 knock out mice chronically infected with rotavirus, the donor cells derived from Peyer's patch of orally infected mice were more efficient than those derived from lung of intranasally infected animals in clearing intestinal infection. These results suggest that different routes of infection induce virus-specific CD8 T cells with distinct homing phenotypes and effector functions as well as variable abilities to clear infection. PMID: 18480435 [PubMed - as supplied by publisher]
Advances in Liver Disease: Highlights From the 58th Annual Meeting of the American Association for the Study of Liver Diseases, November 2-6, 2007, Boston, MA.
Keeffe EB, Duddempudi AT, Jacobson IM.
Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA. PMID: 18477970 [PubMed - in process]
Am J Gastroenterol. 2008 May;103(5):1131-5.
Higher rate of sustained virologic response in chronic hepatitis C genotype 6 treated with 48 weeks versus 24 weeks of peginterferon plus ribavirin.
Nguyen MH, Trinh HN, Garcia R, Nguyen G, Lam KD, Keeffe EB.
Division of Gastroenterology and Hepatology, Stanford University Medical Center, Palo Alto, California, USA.
OBJECTIVES: Infection with hepatitis C virus (HCV) genotype 6 is common in patients from parts of China and Southeast Asia. No study to date has examined the treatment response to peginterferon and ribavirin (PEG IFN + RBV) in these patients, or the effects of treatment duration on sustained virologic response (SVR) rates. METHODS: We performed a retrospective study of 190 consecutive Asian-American patients who were diagnosed with HCV genotype 6 at a gastroenterology clinic in northern California between 2001 and 2004, 66 of whom were treatment-naïve and subsequently completed 24 wk of IFN + RBV or PEG IFN + RBV or 48 wk of PEG IFN + RBV therapy. The primary outcome was SVR. RESULTS: There was no statistical difference in SVR of 31 patients treated with 24 wk of IFN + RBV and in 23 patients treated with 24 wk of PEG IFN + RBV (51.6%vs 39%, P= 0.363). The SVR in 12 patients treated with 48 wk of PEG IFN + RBV was significantly higher than that in those treated for only 24 wk (75%vs 39%, P= 0.044). CONCLUSIONS: Treatment-eligible patients with HCV genotype 6 should be treated with a full course of 48 wk as tolerated. Larger prospective studies of patients with HCV genotype 6 are needed to confirm the optimal treatment duration with PEG IFN + RBV.
PMID: 18477343 [PubMed - indexed for MEDLINE]
Transplantation. 2008 May 15;85(9):1287-9.
Factors affecting survival to intestinal transplantation in the very young pediatric patient.
Mian SI, Dutta S, Le B, Esquivel CO, Davis K, Castillo RO.
Department of Pediatric Gastroenterology, Stanford University School of Medicine, Palo Alto, CA, USA.
BACKGROUND: Very young pediatric patients awaiting intestinal transplantation have a high mortality rate due to long waiting times, scarcity of appropriate size donor organs, and mortality due to sepsis and liver failure. To investigate specific risk factors impacting survival to intestinal transplantation, we performed a 4-year institutional retrospective study comparing children who received grafts by age 18 months with children 18 months or younger who died while on the waiting list. PATIENTS AND METHODS: Twelve children comprised the transplanted group and had the underlying diagnoses: necrotizing enterocolitis, gastroschisis, Hirschsprung's disease, and omphalocele. Ten children comprised the deceased group and had the underlying diagnoses: intestinal atresia, necrotizing enterocolitis, gastroschisis, and midgut volvulus. Multiple risk factors were assessed in these groups. RESULTS: No differences in residual small bowel length, presence of the colon, number of line infections, or number of central lines were found. The average body weight of the transplanted group trended higher, whereas the deceased group had more impairment of hepatic function. Intestinal atresia was the most common diagnosis in the deceased group while none of the transplanted group carried this diagnosis. Ileocecal valve was retained in 80% of the deceased group and in none of the transplanted group. CONCLUSIONS: In children younger than 18 months, risk factors affecting survival to intestinal transplantation include small body size and advanced liver disease. A primary diagnosis of intestinal atresia and the presence of the ileocecal valve may confer additional risk to these very young children. PMID: 18475185 [PubMed - in process]
Pediatr Transplant. 2008 Jun;12(4):442-6.
Prevention of pediatric graft coronary artery disease: atorvastatin.
Chin C, Lukito SS, Shek J, Bernstein D, Perry SB.
Department of Pediatrics, Division of Pediatric Cardiology, Stanford University, Palo Alto, CA, USA. clifford@stanford.edu
Graft coronary artery disease is a significant cause of late graft failure and death after cardiac transplantation. HMG-coenzyme A reductase inhibitors have been used safely in children but their preventative effects against GCAD are not well known. We investigated whether atorvastatin when initiated early could prevent against the development of pediatric GCAD. Pediatric patients (transplanted between October 28, 1992 and July 9, 2004) were stratified into two groups based on whether or not they received atorvastatin early after transplant. Angiograms were reviewed by a single observer blinded to the treatment strategies and clinical outcomes. Actuarial survival method and the Mantel-Cox test were used to assess statistical significance. Freedom from GCAD was higher among those treated with atorvastatin early in the post-transplant course. One, three, and five-yr freedom from GCAD was significantly greater in the early treatment group (97%, 93%, and 93% respectively) compared with the control group (72%, 65%, and 60% respectively, p < 0.005). The early treatment group was also noted for fewer rejection episodes in the first post-transplant year. The use of atorvastatin when initiated early in the post-transplant course appears protective against graft coronary artery disease. PMID: 18466431 [PubMed – in process]
Aliment Pharmacol Ther. 2008 May 9. [Epub ahead of print]
Review article: current antiviral therapy of chronic hepatitis B.
Ayoub WS, Keeffe EB.
Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University Medical Center, Stanford, California, USA.
Background The long-term goals of therapy for chronic hepatitis B are to reduce serum HBV DNA to low or undetectable levels and ultimately reduce or prevent the development of cirrhosis and hepatocellular carcinoma. Aim To review the current treatment of chronic hepatitis B, with a focus on diagnosis and management of resistance and active management of suboptimal responses. Methods A systematic review of the literature, with a focus on recent guidelines, was undertaken Results Among the six drugs licensed for the treatment of chronic hepatitis B in the United States, the preferred agents in 2008 will include entecavir, peginterferon alfa-2a, possibly telbivudine, and tenofovir following licensure. When using an oral agent, a major focus of management is the selection of a drug with high potency and low rate of resistance, and active on-treatment management to optimize therapy. Preventing the sequelae of antiviral drug resistance and appropriate management when resistance is initially detected is also a major focus of current management. The addition of an antiviral agent that is not cross-resistant is critical to restore suppression of viral replication. Conclusions Newer agents and modified treatment strategies, especially using combination therapy, holds promise to optimize the management of patient with chronic hepatitis B by achieving the high potency and the lowest rate of resistance.PMID:18466358 [PubMed – as supplied by publisher]
J Pediatr Hematol Oncol. 2008 May;30(5):396-400.
Maternal T-cell engraftment associated with severe hemophagocytosis of the bone marrow in untreated X-linked severe combined immunodeficiency.
Dvorak CC, Sandford A, Fong A, Cowan MJ, George TI, Lewis DB.
Division of Pediatric Stem Cell Transplantation, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA. dvorakc@peds.ucsf.edu
Maternal engraftment of T cells in severe combined immunodeficiency can lead to graft-versus-host disease of the skin and liver. We report the case of an infant with X-linked severe combined immunodeficiency, confirmed by DNA sequencing of the common gamma chain gene locus, in which this disorder's characteristic peripheral lymphocyte phenotype [T(-)B(+)NK(-)] was obscured by the postnatal onset of hemophagocytic syndrome that included severe B-cell lymphopenia, neutropenia, and anemia. Hemophagocytosis was most likely owing to maternal graft-versus-host disease, as perforin-expressing CD8 T cells, presumably of maternal origin, were prominent in the bone marrow and there was no concurrent severe infection.
PMID: 18458578 [PubMed - in process]
J Infect Dis. 2008 May 2. [Epub ahead of print]
Learning to Appreciate Our Differences.
Relman DA.
Department of Medicine and Department of Microbiology and Immunology, Stanford University, Stanford, and Veterans Affairs Health Care System, Palo Alto, California.
PMID: 18454681 [PubMed - as supplied by publisher]
J Infect Dis. 2008 Mar 1;197 Suppl 2:S58-60.
Humoral and cellular immunity to varicella-zoster virus: an overview.
Arvin AM.
Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305, USA. aarvin@stanford.edu
PMID: 18419410 [PubMed - indexed for MEDLINE]
Transplantation. 2008 Apr 27;85(8):1139-45.
Maturation of dose-corrected tacrolimus predose trough levels in pediatric kidney allograft recipients.
Naesens M, Salvatierra O, Li L, Kambham N, Concepcion W, Sarwal M.
Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA. maarten.naesens@uz.kuleuven.be
BACKGROUND: In contrast to adult kidney recipients, in whom the long-term evolution and clinical determinants of tacrolimus pharmacokinetics are well studied, less is known about the long-term evolution of tacrolimus pharmacokinetics in pediatric kidney transplant recipients. METHODS: One-hundred and five pediatric recipients of a kidney allograft, all treated with a corticosteroid-free immunosuppressive protocol, were included. The evolution of tacrolimus doses and predose trough (C0) levels was recorded at 3, 6, 9, 12, 18, and 24 months after transplantation, as well as all C0 levels obtained in the first 2 years after transplantation. The evolution and clinical determinants of tacrolimus exposure parameters were analyzed. RESULTS: Dose-corrected tacrolimus C0 levels (C0/dose/kg) increased in the first 2 years after kidney transplantation in pediatric recipients (P=0.001). This decrease in dose requirement by time was only significant in children older than 5 years at the time of transplantation (P=0.38, 0.03, and 0.001 for age groups <5, 5-12, and >12 years, respectively). In addition, the younger patients had significantly higher dose requirements (dose/kg) compared with older recipients (P=0.0002). CONCLUSION: Pediatric kidney transplant recipients exhibit maturation of dose-corrected tacrolimus predose trough levels with time after transplantation. This cannot be explained by differences in corticosteroid use, because all patients were treated with a corticosteroid-free protocol. The higher dose requirements for younger recipients and the absence of tacrolimus maturation in the youngest recipients suggest that age-dependent changes in tacrolimus intestinal first-pass effect, metabolism, or distribution play a role. Whether age-specific tacrolimus dosing algorithms will improve outcome needs further study.PMID: 18431234 [PubMed - indexed for MEDLINE]
Obstet Gynecol. 2008 Apr;111(4):927-34.
Pregnancy outcomes in systemic sclerosis, primary pulmonary hypertension, and sickle cell disease.
Chakravarty EF, Khanna D, Chung L.
Division of Immunology and Rheumatology, Department of Medicine, Stanford University School of Medicine, Palo Alto, California, USA. echakravarty@stanford.edu
OBJECTIVE: Systemic sclerosis, primary pulmonary hypertension, and sickle cell disease are uncommon vasculopathic diseases affecting women. We estimated the nationwide occurrence of pregnancies in women with these conditions and compared pregnancy outcomes to the general obstetric population. METHODS: We studied the 2002-2004 Nationwide Inpatient Sample, of the Healthcare Cost and Utilization Project to estimate the number of obstetric hospitalizations and deliveries among women with systemic sclerosis, primary pulmonary hypertension, sickle cell disease, and women in the general population. Pregnancy outcomes included length of hospital stay, hypertensive disorders including preeclampsia, intrauterine growth restriction (IUGR), and cesarean delivery. Multivariable regression analyses were performed using maternal age, race or ethnicity, antiphospholipid antibody syndrome, diabetes mellitus, and renal failure as covariates. RESULTS: Of an estimated 11.2 million deliveries, 504 occurred in women with systemic sclerosis, 182 with primary pulmonary hypertension, and 4,352 with sickle cell disease. Systemic sclerosis, was associated with an increased risk of hypertensive disorders including preeclampsia (odds ratio [OR] 3.71, 95% confidence interval [CI] 2.25-6.15), IUGR (OR 3.74, 95% CI 1.51-9.28), and increased length of hospital stay. Primary pulmonary hypertension was associated with an increase in the odds of antenatal hospitalization (OR 4.67, 95% CI 2.88-7.57), hypertensive disorders including preeclampsia (OR 5.62, 95% CI 2.60-12.15) and a substantial increase in length of hospital stay. Sickle cell disease was associated with an increased odds of antenatal hospitalization (OR 5.56 95% CI 5.08-6.09), hypertensive disorders including preeclampsia (OR 1.78, 95% CI 1.48-2.14), and IUGR (OR 2.91, 95% CI 2.16-3.93), with a modest increase in length of hospital stay. CONCLUSION: Women with systemic sclerosis, primary pulmonary hypertension, and sickle cell disease have significantly increased rates of adverse pregnancy outcomes, requiring extensive preconceptional counseling about the risks of pregnancy. PMID: 18378753 [PubMed - indexed for MEDLINE]
Transplantation. 2008 Mar 27;85(6):827-33.
Asymmetric dimethylarginine and cardiac allograft vasculopathy progression: modulation by sirolimus.
Potena L, Fearon WF, Sydow K, Holweg C, Luikart H, Chin C, Weisshaar D, Mocarski ES, Lewis DB, Valantine HA, Cooke JP.
Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
BACKGROUND: Cardiac allograft vasculopathy (CAV) is a major cause of death after heart transplantation (HT). The reduced bioavailability of endothelium-derived nitric oxide may play a role in endothelial vasodilator dysfunction and thus in the structural changes characterizing CAV. A potential contributor to endothelial pathobiology is asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor. It was hypothesized that ADMA concentrations may influence CAV progression during the first postoperative year. METHODS: Thirty-two consecutive HT recipients underwent intravascular ultrasound evaluation at month 1 and year 1 after HT. Immunosuppression included mycophenolate mofetil (MMF, n=16) and sirolimus (n=16). Change in intimal volume greater than the median and vascular remodeling were major outcome measures. RESULTS: Plasma ADMA levels were associated with subsequent development of intimal hyperplasia (risk ratio [95% confidence interval] =2.72 [1.06-6.94]; P=0.038), and plasma ADMA levels greater than 0.70 micromol/L most accurately identified patients who would have developed intimal hyperplasia. However, ADMA levels did not correlate with negative coronary remodeling. Treatment with sirolimus, as compared with MMF, was associated with significantly lower ADMA levels (0.65+/-0.12 vs. 0.77+/-0.10 micromol/L; P<0.01) and less intimal hyperplasia (risk ratio [95% confidence interval] = 0.08 [0.01-0.56]; P=0.01). CONCLUSIONS: Elevated plasma ADMA is associated with coronary intimal hyperplasia, supporting the importance of nitric oxide synthase inhibition in CAV pathogenesis. Treatment with sirolimus (rather than MMF) is associated with lower ADMA levels and reduced risk of accelerated CAV. PMID: 18360263 [PubMed - indexed for MEDLINE]
Appl Environ Microbiol. 2008 May;74(10):3143-50. Epub 2008 Mar 21.
Linking microbial phylogeny to metabolic activity at the single-cell level by using enhanced element labeling-catalyzed reporter deposition fluorescence in situ hybridization (EL-FISH) and NanoSIMS.
Behrens S, Lösekann T, Pett-Ridge J, Weber PK, Ng WO, Stevenson BS, Hutcheon ID, Relman DA, Spormann AM.
Department of Chemical Engineering and of Civil, Stanford University, Stanford, California 94305-5429, USA.
To examine phylogenetic identity and metabolic activity of individual cells in complex microbial communities, we developed a method which combines rRNA-based in situ hybridization with stable isotope imaging based on nanometer-scale secondary-ion mass spectrometry (NanoSIMS). Fluorine or bromine atoms were introduced into cells via 16S rRNA-targeted probes, which enabled phylogenetic identification of individual cells by NanoSIMS imaging. To overcome the natural fluorine and bromine backgrounds, we modified the current catalyzed reporter deposition fluorescence in situ hybridization (FISH) technique by using halogen-containing fluorescently labeled tyramides as substrates for the enzymatic tyramide deposition. Thereby, we obtained an enhanced element labeling of microbial cells by FISH (EL-FISH). The relative cellular abundance of fluorine or bromine after EL-FISH exceeded natural background concentrations by up to 180-fold and allowed us to distinguish target from non-target cells in NanoSIMS fluorine or bromine images. The method was optimized on single cells of axenic Escherichia coli and Vibrio cholerae cultures. EL-FISH/NanoSIMS was then applied to study interrelationships in a dual-species consortium consisting of a filamentous cyanobacterium and a heterotrophic alphaproteobacterium. We also evaluated the method on complex microbial aggregates obtained from human oral biofilms. In both samples, we found evidence for metabolic interactions by visualizing the fate of substrates labeled with (13)C-carbon and (15)N-nitrogen, while individual cells were identified simultaneously by halogen labeling via EL-FISH. Our novel approach will facilitate further studies of the ecophysiology of known and uncultured microorganisms in complex environments and communities. PMID: 18359832 [PubMed - indexed for MEDLINE] PMCID: PMC2394947 [Available on 09/01/08]
J Pediatr Surg. 2008 Mar;43(3):451-60.
Doxycycline sclerotherapy as primary treatment of head and neck lymphatic malformations in children.
Nehra D, Jacobson L, Barnes P, Mallory B, Albanese CT, Sylvester KG.
Division of Pediatric Surgery, Department of Surgery, Lucile Packard Children's Hospital, Stanford University School of Medicine, Stanford, CA 94305, USA.
PURPOSE: The authors report their experience with doxycycline sclerotherapy as primary treatment of head and neck lymphatic malformations (LMs) in children. METHODS: A retrospective chart review was used to collect data on 11 patients treated with doxycycline sclerotherapy for LMs of the head and neck at our institution since 2003. Radiographic imaging allowed classification of patient LM as macrocystic, microcystic, or mixed according to previously published guidelines. Only patients with macrocystic or mixed lesions were offered doxycycline sclerotherapy. Radiographic imaging and physical examination were used to determine efficacy of treatment. After each treatment, the clinical and radiographic response was characterized as excellent (> or = 95% decrease in lesion size), satisfactory (> or = 50% decrease in volume and asymptomatic), or poor (< 50% decrease in volume or symptomatic). RESULTS: Eleven patients underwent a total of 23 sclerotherapies with an average of 2 treatments per patient (range, 1-4). All 7 patients with macrocystic lesions achieved complete clinical resolution with an average radiographic resolution of 93%. The 4 patients with mixed lesions achieved only partial clinical resolution and an average of 73% radiographic resolution. No patient experienced any adverse effects related to the treatment. At a median follow-up of 8 months, 2 patients (18%) experienced lesion recurrence in the setting of concomitant infection. CONCLUSION: Doxycycline sclerotherapy is safe and effective as a primary treatment modality for macrocystic and mixed LMs of the head and neck in the pediatric population.
PMID: 18358281 [PubMed - indexed for MEDLINE]
Transplantation. 2008 Feb 27;85(4):607-14.
Simultaneous protection against allograft rejection and graft-versus-host disease after total lymphoid irradiation: role of natural killer T cells.
Liu YP, Li Z, Nador RG, Strober S.
Division of Immunology & Rheumatology, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305-5166, USA.
BACKGROUND: The use of combined organ and bone marrow transplantation has been studied extensively in rodent models to induce immune tolerance to organ grafts. However, bone marrow transplants with mature donor T cells can induce graft-versus-host disease even in human leukocyte antigen-matched humans. We determined whether total lymphoid irradiation can simultaneously protect against graft-versus-host disease while facilitating tolerance. METHODS: To more closely model clinical studies, we added mature donor T cells to bone marrow grafts combined with heart grafts, and compared murine graft and host survival after conditioning with nonmyeloablative total body or total lymphoid irradiation and depletive anti-T-cell antibodies. RESULTS: Conditioning with total lymphoid irradiation protected hosts against both graft-versus-host disease and organ graft rejection. Although nonmyeloblative total body irradiation prevented organ graft rejection, all hosts succumbed to lethal graft-versus host disease. Induction of tolerance with total lymphoid irradiation and anti-T-cell antibodies was dependent on the presence of regulatory host natural killer T cells, and expression of CD1d on donor marrow but not heart graft cells. CONCLUSION: Conditioning with total lymphoid irradiation and anti-T-cell antibodies prevented host-versus-donor and donor-versus-host alloimmune responses. Tolerance required host natural killer T-cell recognition of CD1d on donor marrow cells.
PMID: 18347541 [PubMed - indexed for MEDLINE]
J Clin Invest. 2008 Apr;118(4):1417-26.
IRF9 and STAT1 are required for IgG autoantibody production and B cell expression of TLR7 in mice.
Thibault DL, Chu AD, Graham KL, Balboni I, Lee LY, Kohlmoos C, Landrigan A, Higgins JP, Tibshirani R, Utz PJ.
Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, California 94305, USA.
A hallmark of SLE is the production of high-titer, high-affinity, isotype-switched IgG autoantibodies directed against nucleic acid-associated antigens. Several studies have established a role for both type I IFN (IFN-I) and the activation of TLRs by nucleic acid-associated autoantigens in the pathogenesis of this disease. Here, we demonstrate that 2 IFN-I signaling molecules, IFN regulatory factor 9 (IRF9) and STAT1, were required for the production of IgG autoantibodies in the pristane-induced mouse model of SLE. In addition, levels of IgM autoantibodies were increased in pristane-treated Irf9 -/- mice, suggesting that IRF9 plays a role in isotype switching in response to self antigens. Upregulation of TLR7 by IFN-alpha was greatly reduced in Irf9 -/- and Stat1 -/- B cells. Irf9 -/- B cells were incapable of being activated through TLR7, and Stat1 -/- B cells were impaired in activation through both TLR7 and TLR9. These data may reveal a novel role for IFN-I signaling molecules in both TLR-specific B cell responses and production of IgG autoantibodies directed against nucleic acid-associated autoantigens. Our results suggest that IFN-I is upstream of TLR signaling in the activation of autoreactive B cells in SLE.
PMID: 18340381 [PubMed - indexed for MEDLINE] PMCID: PMC2267033
J Infect Dis. 2008 Mar 15;197(6):803-11.
Phenotypic changes in influenza-specific CD8+ T cells after immunization of children and adults with influenza vaccines.
He XS, Holmes TH, Mahmood K, Kemble GW, Dekker CL, Arvin AM, Greenberg HB.
Departments of Medicine, Stanford University School of Medicine, Stanford. xiaosong@stanford.edu
The effect of trivalent inactivated influenza vaccine (TIV) or live attenuated influenza vaccine (LAIV) on the phenotypes of circulating influenza-specific CD8+ T cells was analyzed by interferon (IFN)-gamma flow cytometry and tetramer staining. In adults, the expression of the T cell differentiation marker CD27 on virus-specific CD8+ T cells decreased after LAIV but increased after TIV. In children, expression of the cytotoxicity molecule perforin in influenza-specific CD8+ T cells increased after TIV but not after LAIV. Among children aged 6 months to 4 years who had not been vaccinated previously and who received 2 doses of TIV, CD27 expression decreased after each dose, whereas perforin expression increased after the second dose. These findings indicate that the phenotypic changes of influenza-specific CD8+ T cells differ depending on the type of vaccine and the age of the vaccinee. These differences are potentially affected by the different routes of vaccination and pathways of antigen presentation for TIV and LAIV.PMID: 18279048 [PubMed – indexed for MEDLINE]
Biol Reprod. 2008 Apr;78(4):744-51. Epub 2007 Dec 19.
Regulation of maternal and fetal hemodynamics by heme oxygenase in mice.
Zhao H, Wong RJ, Doyle TC, Nayak N, Vreman HJ, Contag CH, Stevenson DK.
Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305-5208, USA. huizhao2@stanford.edu
Heme oxygenase (HMOX) regulates vascular tone and blood pressure through the production of carbon monoxide (CO), a vasodilator derived from the heme degradation pathway. During pregnancy, the maternal circulation undergoes significant adaptations to accommodate the hemodynamic demands of the developing fetus. Our objective was to investigate the role of HMOX on maternal and fetal hemodynamics during pregnancy in a mouse model. We measured and compared maternal tissue and placental HMOX activity and endogenous CO production, represented by excreted CO and carboxyhemoglobin levels, during pregnancy (Embryonic Days 12.5-15.5) to nonpregnant controls. Micro-ultrasound was used to monitor maternal abdominal aorta diameters as well as blood flow velocities and diameters of fetal umbilical arteries. Tin mesoporphyrin, a potent HMOX inhibitor, was used to inhibit HMOX activity. Changes in maternal vascular tone were monitored by tail cuff blood pressure measurements. Effects of HMOX inhibition on placental structures were assessed by histology. We showed that maternal tissue and placental HMOX activity and CO production were significantly elevated during pregnancy. When HMOX in the placenta was inhibited, maternal and fetal hemodynamics underwent significant changes, with maternal blood pressures increasing. We concluded that increases in maternal tissue and placental HMOX activity contribute to the regulation of peripheral vascular resistance and therefore are important for the maintenance of normal maternal vascular tone and fetal hemodynamic functions during pregnancy. PMID: 18094356 [PubMed - indexed for MEDLINE]
Rev Gastroenterol Disord. 2005;5 Suppl 3:26-35.
Antibiotics in the management of hepatic encephalopathy: an evidence-based review.
Rothenberg ME, Keeffe EB.
Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA.
Hepatic encephalopathy (HE) is an increasingly prevalent and debilitating condition that occurs in functional hepatic insufficiency. It is marked by fluctuating neuropsychiatric and cognitive impairment, which can be severe and life threatening. Hepatic encephalopathy is a diagnosis of exclusion; thus, it is challenging to diagnose definitively and to investigate in clinical trials. High response rates in the placebo arms of well-conducted studies demonstrate that the most effective treatment for HE is the correction of known precipitating triggers. However, pharmacological therapies may also be helpful. Although the precise pathogenesis remains unknown, bacterially derived neurotoxins from enteric flora likely play an important role. Based on this hypothesis and on accumulating clinical experience documented in randomized trials, oral antibiotics have emerged as an important treatment adjunct. This article addresses the qualities of an ideal antibiotic and reviews the literature on 4 antibiotics used to treat HE: neomycin, metronidazole, vancomycin, and rifaximin, with the most promising of these drugs appearing to be rifaximin. Unfortunately, most studies of the treatment of HE are difficult to interpret due to small sample sizes, methodological flaws, vulnerability to bias, and the intrinsic challenges of studying HE. Many studies have erroneously concluded that treatments are equivalent simply because no significant difference between treatment arms was detected. Consequently, the literature generally lacks definitive data from large, randomized, placebo-controlled trials. Nevertheless, the data suggest that minimally absorbed antibiotics are emerging as a safe and effective approach for the treatment of HE. PMID: 17713457 [PubMed – indexed for MEDLINE]
ITI Faculty and Researchers’ Publications for May 2007
1: Immunogenetics. 2007 Jun;59(6):517-22. Epub 2007 Apr 21.
The expanded cattle KIR genes are orthologous to the conserved single-copy KIR3DX1 gene of primates.
Guethlein LA, Abi-Rached L, Hammond JA, Parham P. Department of Structural Biology, Fairchild D-159, 299 Campus Drive West,Stanford, CA, 94305, USA, libby.guethlein@stanford.edu.
Cattle are the only non-primate species for which expansion of the killer cell immunoglobulin-like receptor (KIR) genes has been reported. We analyzed cattle KIR sequences to determine their relationship to the two divergent lineages of primate KIR: one comprising the KIR3DX1 gene of unknown function, the second comprising all other primate KIR genes, which encode variable major histocompatibility complex class I receptors. Phylogenetics and analysis of repetitive elements shows that cattle KIR subdivide into the same two lineages as primate KIR. Unlike the primates, the lineage of variable and likely functional cattle KIR corresponds to the KIR3DX1 lineage of primate KIR, whereas the variable lineage of primate KIR is represented in cattle by one KIR gene anda related gene fragment. PMID: 17450355 [PubMed - in process]
2: J Allergy Clin Immunol. 2007 May 4; [Epub ahead of print]
Mast cell-derived TNF contributes to airway hyperreactivity, inflammation, and T(H)2 cytokine production in an asthma model in mice.
Nakae S, Ho LH, Yu M, Monteforte R, Iikura M, Suto H, Galli SJ. From the Department of Pathology, Stanford University School of Medicine.
BACKGROUND: Mast cells, IgE, and TNF, which have been implicated in human atopic asthma, contribute significantly to the allergic airway inflammation induced by ovalbumin (OVA) challenge in mice sensitized with OVA without alum. However, it is not clear to what extent mast cells represent a significant source of TNF in this mouse model. OBJECTIVE: We investigated the importance of mast cell-derived TNF in a mast cell-dependent model of OVA-induced airway hyperreactivity (AHR)and allergic airway inflammation. METHODS: Features of this model of airway inflammation were analyzed in C57BL/6J-wild-type mice, mast cell-deficient C57BL/6J-Kit(W-sh)(/W-sh) mice, and C57BL/6J Kit(W-sh/W-sh) mice that had been systemically engrafted with bone marrow-derived cultured mast cells from C57BL/6J-wild-type or C57BL/6J-TNF(-/-) mice. RESULTS: Ovalbumin-induced AHR and airway inflammation were significantly reduced in mast cell-deficient Kit(W-sh/W-sh) mice versus wild-type mice. By contrast, Kit(W-sh/W-sh) mice that had been engrafted with wild-type but not with TNF(-/-) bone marrow-derivedcultured mast cells exhibited responses very similar to those observed in wild-type mice. Mast cells and mast cell-derived TNF were not required forinduction of OVA-specific memory T cells in the sensitization phase, butsignificantly enhanced lymphocyte recruitment and T(H)2 cytokine production inthe challenge phase. CONCLUSION: Mast cell-derived TNF contributes significantlyto the pathogenesis of mast cell-dependent and IgE-dependent, OVA-induced allergic inflammation and AHR in mice, perhaps in part by enhancing lymphocyte recruitment and T(H)2 cytokine production. CLINICAL IMPLICATIONS: Our findings in mice support the hypothesis that mast cell-derived TNF can promote allergicinflammation and AHR in asthma. PMID: 17482668 [PubMed - as supplied by publisher]
3: Genes Dev. 2007 May 1;21(9):1086-97.
Inhibition of U snRNP assembly by a virus-encoded proteinase.
Almstead LL, Sarnow P. Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305, USA.
It has been proposed that defects in the assembly of spliceosomal uridine-rich small nuclear ribonucleoprotein (U snRNP) complexes could account for the death of motor neurons in spinal muscular atrophy (SMA). We discovered that infection of cultured cells with poliovirus results in the specific cleavage of the host factor Gemin3 by a virus-encoded proteinase, 2A(pro). Gemin3 is a component of the macromolecular SMN complex that mediates assembly of U snRNP complexes by aiding the heptameric oligomerization of Sm proteins onto U snRNAs. Using in vitro Sm core assembly assays, we found that lowering the intracellular amounts of Gemin3 by either poliovirus infection or small interfering RNA (siRNA)-mediated knockdown of Gemin3 resulted in reduced assembly of U snRNPs. Immunofluorescence analyses revealed a specific redistribution of Sm proteins from the nucleoplasm to the cytoplasmic periphery of the nucleus in poliovirus-infected cells. We propose that defects in U snRNP assembly may be shared features of SMA and poliomyelitis. PMID: 17473171 [PubMed - in process]
4: Hum Immunol. 2007 May;68(5):309-23. Epub 2007 Mar 12.
Donor-Recipient Combinations of Group A and B KIR Haplotypes and HLA class I Ligand Affect the Outcome of HLA-Matched, Sibling Donor Hematopoietic Cell Transplantation.
McQueen KL, Dorighi KM, Guethlein LA, Wong R, Sanjanwala B, Parham P. Departments of Structural Biology, and Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA.
The influence of donor and recipient killer immunoglobulin-like receptor (KIR)genotype on the outcome of hematopoietic cell transplantation between human leukocyte antigen (HLA)-matched siblings was investigated. Transplants were divided into four groups according to the combination of group A and B KIR haplotypes in the transplant donor and recipient. Overall survival of myeloid patients varied with KIR genotype combination. Best survival was associated with the donor lacking and the recipient having group B KIR haplotypes; poorest survival was associated with the donor having and the recipient lacking group B KIR haplotypes. The latter combination was also associated with increased relapse and acute graft-versus-host disease (GVHD). However, its detrimental effects were seen only for transplants where the recipient and donor were homozygous for the C1 KIR ligand and therefore lacked the C2 ligand. Presence of the Bw4 ligand was also associated with increased acute GVHD. In contrast presence of both KIR3DL1 and its cognate Bw4 ligand was associated with decreased nonrelapse mortality. Analysis of the KIR genes individually revealed KIR2DS3 as a protective factor for chronic GVHD. The results suggest how simple assessments of KIR genotype might inform the selection of donors for hematopoietic cell transplantation. PMID: 17462498 [PubMed - in process]
5: Int Immunol. 2007 May;19(5):645-55. Epub 2007 Apr 19.
Influenza A virus elevates active cathepsin B in primary murine DC.
Burster T, Giffon T, Dahl ME, Bjorck P, Bogyo M, Weber E, Mahmood K, Lewis DB, Mellins ED. Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA.
Dendritic cells (DCs) act as a first-line recognition system for invading pathogens, such as influenza A. The interaction of DC with influenza A virus results in DC activation via endosomal Toll-like receptors and also leads to presentation of viral peptides on MHC class II molecules. Prior work demonstrated that influenza A virus (A/HKx31; H3N2) infection of BALB/c mice activates lung DCs for antigen presentation, and that the enhanced function of these cells persists long after viral clearance and resolution of the virus-induced inflammatory response. Whether influenza A virus has acute orlonger-lasting effects on the endo/lysosomal antigen-processing machinery of DCs has not been studied. Here, we show that antigen presentation from intact protein antigen, but not peptide presentation, results in increased T cell stimulation by influenza-exposed lung DCs, suggesting increased antigen processing/loading in these DCs. We find that cathepsin (Cat) B levels and activity are substantially up-regulated in murine lung DCs, harvested 30 days after A/HKx31 infection. CatB levels and activity are also increased in murinesplenic and bone marrow-derived DCs, following short-term in vitro exposure to UV-inactivated influenza A virus. Modest effects on CatX are also seen during in vivo and in vitro exposure to influenza A virus. Using a cell permeable Cat inhibitor, we show Cats in influenza-exposed DCs to be functional and required for generation of a T cell epitope from intact ovalbumin. Our findings indicate that influenza A virus affects the MHC class II antigen-processing pathway, anessential pathway for CD4(+) T cell activation. PMID: 17446210 [PubMed - in process]
6: J Immunol. 2007 May 1;178(9):5496-504.
Kruppel-like transcription factor 13 regulates T lymphocyte survival in vivo.
Zhou M, McPherson L, Feng D, Song A, Dong C, Lyu SC, Zhou L, Shi X, Ahn YT, Wang D, Clayberger C, Krensky AM. Department of Pediatrics, Stanford University, Palo Alto, CA 94305.
Kruppel-like transcription factor (KLF)13, previously shown to regulate RANTES expression in vitro, is a member of the Kruppel- like family of transcription factors that controls many growth and developmental processes. To ascertain the function of KLF13 in vivo, Klf13-deficient mice were generated by gene targeting. As expected, activated T lymphocytes from Klf13(-/-) mice show decreased RANTES expression. However, these mice also exhibit enlarged thymi and spleens. TUNEL, as well as spontaneous and activation-induced death assays,demonstrated that prolonged survival of Klf13(-/-) thymocytes was due to decreased apoptosis. Microarray analysis suggests that protection from apoptosis-inducing stimuli in Klf13(-/-) thymocytes is due in part to increasedexpression of BCL-X(L), a potent antiapoptotic factor. This finding wasconfirmed in splenocytes and total thymocytes by real-time quantitative PCR and Western blot as well as in CD4(+)CD8(-) single-positive thymocytes by real-time quantitative PCR. Furthermore, EMSA and luciferase reporter assays demonstrated that KLF13 binds to multiple sites within the Bcl-X(L) promoter and results in decreased Bcl-X(L) promoter activity, making KLF13 a negative regulator of BCL-X(L). PMID: 17442931 [PubMed - in process]
7: J Rheumatol. 2007 May;34(5):1040-1050. Epub 2007 Apr 15.
Safety and Efficacy of Adalimumab in Treatment of Patients with Psoriatic Arthritis Who Had Failed Disease Modifying Antirheumatic Drug Therapy.
Genovese MC, Mease PJ, Thomson GT, Kivitz AJ, Perdok RJ, Weinberg MA, Medich J, Sasso EH. From the Division of Immunology and Rheumatology, Stanford University Medical Center, Palo Alto, California; Swedish Medical Center, Seattle, Washington; CIADS Research, University of Manitoba, Winnipeg, Manitoba, Canada; Altoona Center for Clinical Research, Duncansville, Pennsylvania; and Abbott Laboratories, Abbott Park, Illinois, USA.
OBJECTIVE: To demonstrate the safety and efficacy of adalimumab for thetreatment of active psoriatic arthritis (PsA) in patients with an inadequate response to disease modifying antirheumatic drugs (DMARD). METHODS: In a placebo controlled, double-blind, randomized, multicenter study, patients were treated for 12 weeks with subcutaneous injections of adalimumab 40 mg every other week (eow) or placebo, followed by a period of open-label treatment with adalimumab 40 mg eow. The primary efficacy endpoint was the percentage of patients who met the American College of Rheumatology (ACR20) core criteria at Week 12. Secondaryefficacy measures included the modified Psoriatic Arthritis Response Criteria (PsARC) and assessments of disability, psoriatic lesions, and quality of life. For missing data, nonresponder imputation was used for ACR and PsARC scores and last observation carried forward for other measures. RESULTS: A total of 100 patients received study drug (51 adalimumab, 49 placebo). At Week 12, an ACR20 response was achieved by 39% of adalimumab patients versus 16% of placebo patients (p = 0.012), and a PsARC response was achieved by 51% with adalimumabversus 24% with placebo (p = 0.007). At Week 12, measures of skin lesions and disability were statistically significantly improved with adalimumab. After Week 12, open-label adalimumab provided continued improvement for adalimumab patients and initiated rapid improvement for placebo patients, with ACR20 response rates of 65% and 57%, respectively, observed at Week 24. Serious adverse events hadsimilar frequencies during therapy with placebo (4.1%), blinded adalimumab (2.0%), and open-label adalimumab (3.1%). No serious infections occurred during adalimumab therapy. CONCLUSION: In this study of patients who had active PsA and a previous, inadequate response to DMARD therapy, adalimumab was well toleratedand significantly reduced the signs, symptoms, and disability of PsA during 12 weeks of blinded and 12 weeks of open-label therapy. Adalimumab also improved psoriasis in these patients. PMID: 17444593 [PubMed - as supplied by publisher]
8: Menopause. 2007 May/June;14(7 Suppl. 1):580-585.
Elective oophorectomy for benign gynecological disorders.
Shoupe D, Parker WH, Broder MS, Liu Z, Farquhar C, Berek JS. From the 1Keck School of Medicine of the University of Southern California, Los Angeles, CA; 2UCLA School of Medicine, Los Angeles, CA; 3Cerner Health Insights, Los Angeles, CA; 4University of Auckland School of Medicine, Auckland, New Zealand; and 5Stanford School of Medicine, Stanford, CA.
OBJECTIVE:: To review the risks and benefits of elective oophorectomy and to make a clinical recommendation for an appropriate age when benefits of this procedure outweigh the risks. DESIGN:: The risks and benefits of oophorectomy as detailed in published articles are reviewed with regard to quality-of-life issues and mortality outcomes in oophorectomized versus nonoophorectomized women from five diseases linked to ovarian hormones (coronary heart disease, ovarian cancer, breast cancer, stroke, and hip fracture). RESULTS:: Numerous reportslink oophorectomy to higher rates of cardiovascular disease, steoporosis, hip fractures, dementia, short-term memory impairment, decline in sexual function, decreased positive psychological well-being, adverse skin and body composition changes, and adverse ocular changes, as well as more severe hot flushes and urogenital atrophy. The potential benefits associated with oophorectomy include prevention of ovarian cancer, a decline in breast cancer risk, and a reducedrisk of pelvic pain and subsequent ovarian surgery. In our study of long-term mortality after oophorectomy using Markov modeling, preservation of ovaries until women are at least aged 65 years was associated with higher survival rates. For women between ages 50 and 54 with hysterectomy and ovarian preservation, the probability of surviving to age 80 was 62% versus 54% if oophorectomy was performed. This 8% difference in survival is primarily due to fewer women dying from cardiovascular heart disease and/or hip fracture. Thissurvival advantage far outweighs the 0.47% increased mortality rate from ovarian cancer prevented by oophorectomy. If surgery occurred between ages 55 and 59,the survival advantage was 4%. After age 64 there were no significant differences in survival rates. Prior literature supports our conclusion of a benefit over risk for ovarian conservation. CONCLUSIONS:: Elective oophorectomy is associated with short-and long-term health consequences that merit seriousconsideration. For women with an average risk of ovarian cancer, ovarian conservation until at least age 65 seems to benefit long-term survival. PMID: 17476148 [PubMed - as supplied by publisher]
9: Mycoses. 2007 May;50(3):227-31.
Treating disseminated fusariosis: amphotericin B, voriconazole or both?
Ho DY, Lee JD, Rosso F, Montoya JG. Department of Medicine, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, USA.
Disseminated Fusarium infection can cause significant morbidity and mortality in immunocompromised patients. We present a case of disseminated fusariosis in a patient with neutropenic fever successfully treated using both liposomal amphotericin B and voriconazole. Combination anti-fungal therapy may be considered for such patients, particularly for those failing single-drug therapy. PMID: 17472622 [PubMed - in process] 10: Pediatr Transplant. 2007 May;11(3):267-71. Optimizing outcomes for neonatal ARPKD. Beaunoyer M, Snehal M, Li L, Concepcion W, Salvatierra O Jr, Sarwal M. Department of Transplant Surgery, Stanford University, Stanford, CA 94304, USA. A retrospective analysis was conducted on 10 consecutive cases of neonatal ARPKD, 9 of whom received kidney transplants (KT). All were diagnosed antenatally (n = 6) or at birth. In the first month of life 70% required ventilatory support. Pre-emptive bilateral nephrectomy and peritoneal dialysis (PD) catheter placement were performed in 9 at a mean age of 7.8 +/- 11.9 months. The indications for nephrectomy were massive kidneys, resulting in suboptimal nutrition and respiratory compromise. All patients received assisted enteral nutrition, with significant increase in mean tolerated feeds following nephrectomy (p < 0.05), with increase in mean normalized weight and height (0.92and 1.2 delta SDS respectively), by one year post-transplantation. KT was performed at a mean age and weight of 2.5 +/- 1.4 years and 13.3 +/- 6.1 kg. The mean creatinine clearance at one year post-KT was 91.3 +/- 38.1 mls/min/1.73 m(2), with a projected graft life expectancy of 18.4 years. Patient survival was 89% and death censored graft survival was 100%, at a mean follow-up of 6.1 +/- 4.5 years post-transplant. Six patients demonstrated evidence of hepatic fibrosis, one of which required liver transplantation. In patients with massive kidneys from ARPKD, pre-emptive bilateral nephrectomy, supportive PD and earlyaggressive nutrition, can minimize early infant mortality, so that subsequent KT can be performed with excellent patient and graft survival. PMID: 17430481 [PubMed - in process]
11: Transplantation. 2007 Apr 27;83(8):1114-21.
Rapamycin Inhibits Proliferation of Epstein-Barr Virus-Positive B-cell Lymphomas Through Modulation of Cell-Cycle Protein Expression.
Vaysberg M, Balatoni CE, Nepomuceno RR, Krams SM, Martinez OM. 1 Program in Immunology, Division of Transplantation, Stanford University School of Medicine, Stanford, CA. 2 Department of Surgery, Division of Transplantation, Stanford University School of Medicine, Stanford, CA.
BACKGROUND.: Posttransplant lymphoproliferative disease (PTLD) is a serious complication of solid organ and bone marrow transplantation and is closely associated with Epstein-Barr virus (EBV) infection. We have previously shown that rapamycin (RAPA) directly inhibits the in vitro and in vivo proliferation of EBV-infected B lymphoblastoid cell lines (SLCL), derived from patients with PTLD, by arresting cells in the G1 phase of the cell cycle. The aim of this study is to elucidate the mechanism by which RAPA causes cell cycle arrest in EBV B cells. METHODS.: SLCL were cultured without or with RAPA (10 ng/ml) andG1-associated cell cycle proteins were analyzed by immunoblot and densitometric analysis. CDK complexes were immunoprecipitated and incubated with retinoblastoma protein (Rb) substrate. Kinase activity of the complex was determined by Western blot with anti-phospho-Rb antibodies. RESULTS.: We show that RAPA decreased both Cyclin D2 and Cyclin D3 protein levels. Furthermore, RAPA decreased the protein levels of cyclin dependent kinase 4 (CDK4) and increased the expression of the CDK inhibitor p27. In contrast, expression of the CDK inhibitor p21 was markedly inhibited by RAPA in the SLCL. Finally, in vitro kinase assays revealed that downstream hyperphosphorylation of Rb by CDK complexes was also decreased by RAPA. CONCLUSION.: The results presented here elucidate key targets of RAPA-induced cell cycle arrest, provide insight into the growth pathways of EBV B-cell lymphomas, and demonstrate the potential for RAPA as a therapeutic option in the treatment of PTLD and other EBV lymphomas. PMID: 17452903 [PubMed - in process]
12: Mol Ther. 2007 Apr 24; [Epub ahead of print]
Histone Modifications are Associated with the Persistence or Silencing of Vector-mediated Transgene Expression in vivo.
Riu E, Chen ZY, Xu H, He CY, Kay MA. [1] 1Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA [2] 2Department of Genetics, Stanford University School of Medicine, Stanford, California, USA.
One of the major obstacles to success in non-viral gene therapy is transcriptional silencing of the DNA vector. The mechanisms underlying gene silencing/repression in mammalian cells are complex and remain unclear. Because changes in chromatin structure and, in particular, histone modifications are involved in transcriptional regulation of endogenous genes, we hypothesized that changes in the pattern of histone modifications were related to the observed transcriptional silencing of exogenous DNA vectors. We used antibodies againstspecific modified histones to perform chromatin immunoprecipitation (ChIP) analyses on liver lysates from mice transfected with two types of plasmids: (i) DNA minicircles (MCs) devoid of bacterial plasmid backbone DNA, which showed marked persistence of transgene expression, and (ii) their parental plasmids, which were silenced over time. Silencing of the transgene from the parental vectors was accompanied by an increase in heterochromatin-associated histone modifications and a decrease in modifications typically associated with euchromatin. Conversely, the pattern of histone modifications on the MC DNA wasconsistent with euchromatin. Our data indicates that (i) episomal vectors undergo chromatinization in vivo, and (ii) both persistence and silencing of transgene expression are associated with specific histonemodifications.Molecular Therapy (2007) doi:10.1038/mt.sj.6300177. PMID: 17457320 [PubMed - as supplied by publisher]
13: J Exp Med. 2007 Apr 23; [Epub ahead of print]
Type I interferon signaling is required for activation of the inflammasome during Francisella infection.
Henry T, Brotcke A, Weiss DS, Thompson LJ, Monack DM. Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305.
Francisella tularensis is a pathogenic bacterium whose virulence is linked to its ability to replicate within the host cell cytosol. Entry into the macrophage cytosol activates a host-protective multimolecular complex called the inflammasome to release the proinflammatory cytokines interleukin (IL)-1beta and -18 and trigger caspase-1-dependent cell death. In this study, we show that cytosolic F. tularensis subspecies novicida (F. novicida) induces a type Iinterferon (IFN) response that is essential for caspase-1 activation,inflammasome-mediated cell death, and release of IL-1beta and -18. Extensive type I IFN-dependent cell death resulting in macrophage depletion occurs in vivo during F. novicida infection. Type I IFN is also necessary for inflammasome activation in response to cytosolic Listeria monocytogenes but not vacuole-localized Salmonella enterica serovar Typhimurium or extracellular adenosine triphosphate. These results show the specific connection between type I IFN signaling and inflammasome activation, which are two sequential events triggered by the recognition of cytosolic bacteria. To our knowledge, this isthe first example of the positive regulation of inflammasome activation. This connection underscores the importance of the cytosolic recognition of pathogens and highlights how multiple innate immunity pathways interact before commitment to critical host responses. PMID: 17452523 [PubMed - as supplied by publisher]
14: J Perinatol. 2007 Apr 19; [Epub ahead of print]
Inhaled nitric oxide in infants >1500 g and <34 weeks gestation with severe respiratory failure.
Meurs KP, Hintz SR, Ehrenkranz RA, Lemons JA, Ball MB, Poole WK, Perritt R, Das A, Higgins RD, Stevenson DK. 1Division of Neonatal and Developmental Medicine, School of Medicine and Lucile Packard Children's Hospital, Stanford University, Palo Alto, CA, USA.
Objective:Inhaled nitric oxide (iNO) use in infants >1500 g, but <34 weeks gestation with severe respiratory failure will reduce the incidence of death and/or bronchopulmonary dysplasia (BPD).Study Design:Infants born at <34 weeks gestation with a birth weight >1500 g with respiratory failure were randomly assigned to receive placebo or iNO.Results:Twenty-nine infants were randomized. There were no differences in baseline characteristics, but the status atrandomization showed a statistically significant difference in the use of high-frequency ventilation (P=0.03). After adjustment for oxygenation index entry strata, there was no difference in death and/or BPD (adjusted relative risk (RR) 0.80, 95% confidence interval (CI) 0.43 to 1.48; P=0.50), death (adjusted RR 1.26, 95% CI 0.47 to 3.41; P=0.65) or BPD (adjusted RR 0.40, 95% CI 0.47 to 3.41; P=0.21).Conclusions:Although sample size limits our ability tomake definitive conclusions, this small pilot trial of iNO use in premature infants >1500 g and <34 weeks with severe respiratory failure suggests that iNO does not affect the rate of BPD and/or death.Journal of Perinatology advance online publication, 19 April 2007; doi:10.1038/sj.jp.7211690. PMID: 17443204 [PubMed - as supplied by publisher]
15: Science. 2007 Apr 13;316(5822):291-4.
Structural insight into pre-B cell receptor function.
Bankovich AJ, Raunser S, Juo ZS, Walz T, Davis MM, Garcia KC. Program in Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
The pre-B cell receptor (pre-BCR) serves as a checkpoint in B cell development. In the 2.7 angstrom structure of a human pre-BCR Fab-like fragment, consisting of an antibody heavy chain (HC) paired with the surrogate light chain, the "unique regions" of VpreB and lambda5 replace the complementarity-determining region 3 (CDR3) loop of an antibody light chain and appear to "probe" the HC CDR3, potentially influencing the selection of the antibody repertoire. Biochemical analysis indicates that the pre-BCR is impaired in its ability torecognize antigen, which, together with electron microscopic visualization of a pre-BCR dimer, suggests ligand-independent oligomerization as the likely signaling mechanism. Publication Types: Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't PMID: 17431183 [PubMed - indexed for MEDLINE]
16: J Virol. 2007 Apr 11; [Epub ahead of print]
Binding dynamics of hepatitis C virus' NS5A amphipathic peptide to cell and model membranes.
Cho NJ, Cheong KH, Lee CH, Frank CW, Glenn JS. Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305; Department of Chemical Engineering, Stanford University, Stanford, CA 94305; Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford University, Stanford, CA, 94305.
Membrane association of the hepatitis C virus (HCV) NS5A protein is required for viral replication. This association is dependent on an N-terminal amphipathic helix (AH) within NS5A and is restricted to a subset of host cell intracellular membranes. The mechanism underlying this specificity is not known, but it may suggest a novel strategy for developing specific antiviral therapy. Here we have probed the mechanistic details of NS5A amphipathic helix-mediated binding toboth cellular-derived and model membranes using biochemical membrane flotation and quartz crystal microbalance with dissipation (QCM-D). In both assays, we observed AH-mediated binding to model lipid bilayers. When cellular-derived membranes were coated on the quartz nano-sensor, however, significantly more binding was detected and the QCM-derived kinetic measurements suggested the existence of an interacting receptor in the target membranes. Biochemical flotation assays performed with trypsin-treated cellular-derived membranes exhibited reduced amphipathic helix-mediated membrane binding, while membranebinding of control cytochrome b5 remained unaffected. Similarly, trypsin treatment of the nano-sensor coated with cellular membranes abolished amphipathic helix peptide binding to the cellular membranes but did not affect the binding of a control lipid-binding peptide. These results, therefore, suggest that a protein plays a critical role in mediating and stabilizing the binding of NS5A's amphipathic helix to its target membrane. These results also demonstrate the successful development of a new nano-sensor technology ideal both for studying the interaction between a protein and its target membrane, and for developing inhibitors of that interaction. PMID: 17428867 [PubMed - as supplied by publisher]
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