188 research outputs found

    The Nuclearization of Biology Is a Threat to Health and Security

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78142/1/bsp.2009.0047.pd

    Biodefense Research: A Win-Win Challenge

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63273/1/bsp.2008.1114.pd

    Resilience Assessment : International Best Practice Principles

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    PURPOSE This document sets out international best-practice principles for resilience assessment being undertaken within an impact assessment (IA) of some project, plan, programme, or policy (in this context, its function may be different to that of a self-standing resilience assessment). Resilience assessment can contribute to impact assessment by defining specific disturbances that can lead to failure of natural, social, and engineered systems. The disturbance can be caused either by the proposed action, factors beyond the influence of proposed action, or combination of both. The impact assessment can consider all these factors within one coherent framework. It can identify synergies and knock-on effects that can cause potential system failures, and advise on interventions that avoid failures in the critical functions of the system BACKGROUND Resilience assessment evaluates the structure and function of a system of focus (hereafter ‘focal system’) and, in the context of an impact assessment, focuses on the effects of the proposed action on the resilience of that focal system. The focal system can include: socio-ecological, biophysical, engineering, technological, or other components. Resilience assessment should ideally examine the consequences of the proposed action in combination with internal or external factors that may collectively influence the resilience of the focal system (e.g., biophysical system change caused by global warming on engineered structures)

    Kaposi’s Sarcoma-Associated Herpesvirus Increases PD-L1 and Proinflammatory Cytokine Expression in Human Monocytes

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    ABSTRACT Kaposi’s sarcoma-associated herpesvirus (KSHV) is associated with the human malignancy Kaposi’s sarcoma and the lymphoproliferative disorders primary effusion lymphoma and multicentric Castleman’s disease. KSHV establishes lytic infection of monocytes in vivo , which may represent an important cellular reservoir during KS disease progression. KS tumors consist of latently infected endothelial cells; however, lytic phase gene products are important for KS onset. Early KS lesion progression is driven by proinflammatory cytokines supplied by immune cell infiltrates including T cells and monocytes. KSHV-infected monocytes may supply the lytic viral products and the inflammatory milieu conducive to KS tumor progression. To establish successful infection, KSHV extensively modulates the host immune system. KSHV antigens activate both innate and adaptive immune responses including KSHV-specific T cells, but lifelong infection is still established. Programmed death ligand 1 (PD-L1) is a prosurvival cell surface protein that suppresses T-cell-mediated killing. PD-L1 is variably present on various tumor cells and is a targetable marker for cancer treatment. We show that KSHV infection of human monocytes increases PD-L1 expression and transcription in a dose-dependent manner. We also saw evidence of lytic gene expression in the KSHV-infected monocytes. Intact KSHV is needed for full PD-L1 response in human monocytes. KSHV induces a general proinflammatory cytokine milieu including interleukins 1α, 1β, and 6, which have been implicated in early KS lesion progression. KSHV-mediated PD-L1 increase may represent a novel mechanism of KSHV-mediated immune modulation to allow for virus survival and eventually malignant progression. IMPORTANCE KSHV is the etiologic agent of Kaposi’s sarcoma and the lymphoproliferative disorders primary effusion lymphoma and multicentric Castleman’s disease. Programmed death ligand 1 (PD-L1) is an immunosuppressive cell surface marker that inhibits T cell activation. We report that KSHV infection of primary human monocytes upregulates PD-L1 transcription and protein expression. Analysis of the cytokine and chemokine milieu following KSHV infection of monocytes revealed that KSHV induces interleukins 1α, 1β, and 6, all of which have been implicated in KS development. Our work has identified another potential immune evasion strategy for KSHV and a potential target for immunotherapy of KSHV-derived disease

    Fate and expression of simian virus 40 DNA after introduction into murine cells under nonselective conditions

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    When SV40 infects mouse cells, it does not replicate but instead causes neoplastic transformation of a small percentage of the cells. It is unknown, however, what happens to the virus in those cells that do not become transformed. We introduced SV40 into mouse cells by nonselective means, either by cotransfection of SV40 DNA with a selectable marker or by random cloning of SV40-infected cells. We analyzed the fate of viral DNA sequences, expression of T antigens, and transformation properties of these cells. We found that, upon infection, viral DNA integration occurs at a frequency that is at least 10-fold higher than the frequency of transformation. The majority of these cells are not transformed due to lack of expression of T antigen. One cell line which expresses a truncated T antigen is not transformed. We have mapped the viral sequences in the genome of these cells and find that integration in the large T intron is probably responsible for the defect. Lack of transformation can therefore be attributed to both cellular and viral factors, namely, introduction of viral DNA into cells that are resistant to transformation or integration of viral DNA in such a way that T antigen expression is prohibited.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26708/1/0000258.pd

    Fecal DNA versus Fecal Occult Blood for Colorectal-Cancer Screening in an Average-Risk Population

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    BACKGROUND Although fecal occult-blood testing is the only available noninvasive screening method that reduces the risk of death from colorectal cancer, it has limited sensitivity. We compared an approach that identifies abnormal DNA in stool samples with the Hemoccult II fecal occult-blood test in average-risk, asymptomatic persons 50 years of age or older. METHODS Eligible subjects submitted one stool specimen for DNA analysis, underwent standard Hemoccult II testing, and then underwent colonoscopy. Of 5486 subjects enrolled, 4404 completed all aspects ofthe study. A subgroup of 2507 subjects was analyzed, including all those with a diagnosis of invasive adenocarcinoma or advanced adenoma plus randomly chosen subjects with no polyps or minor polyps. The fecal DNA panel consisted of 21 mutations. RESULTS The fecal DNA panel detected 16 of 31 invasive cancers, whereas Hemoccult II identified 4 of 31 (51.6 percent vs. 12.9 percent, P=0.003). The DNA panel detected 29 of 71 invasive cancers plus adenomas with high-grade dysplasia, whereas Hemoccult II identified 10 of 71 (40.8 percent vs. 14.1 percent, P<0.001). Among 418 subjects with advanced neoplasia (defined as a tubular adenoma at least 1 cm in diameter, a polyp with a villous histologic appearance, a polyp with high-grade dysplasia, or cancer), the DNA panel was positive in 76 (18.2 percent), whereas Hemoccult II was positive in 45 (10.8 percent). Specificity in subjects with negative findings on colonoscopy was 94.4 percent for the fecal DNA panel and 95.2 percent for Hemoccult II. CONCLUSIONS Although the majority of neoplastic lesions identified by colonoscopy were not detected by either noninvasive test, the multitarget analysis of fecal DNA detected a greater proportion of important colorectal neoplasia than did Hemoccult II without compromising specificity

    An SV40 transformation revertant due to a host mutation: Isolation and complementation analysis

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    We have isolated an SV40 transformation revertant cell line, CLi L, by selection for normal cells whose growth is inhibited under low serum conditions. This line expresses a single, wild-type copy of large T antigen, yet is not transformed. It is not retransformable by transfection of SV40 DNA or infection with a recombinant retrovirus encoding large T antigen. Resistance to transformation therefore appears to be due to a cellular mutation. Fusion of CL1 L cells to normal 3T3 cells or SV40-transformed cells results in somatic cell hybrids that are transformed, indicating that resistance is recessive. In addition, fusion of CL1L cells to another SV40 transformation-resistant line, A27, results in transformed hybrids, indicating the existence of discrete complementation groups with respect to SV40 transformation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30140/1/0000517.pd

    Effectiveness and safety of serial endoscopic ultrasound–guided celiac plexus block for chronic pancreatitis

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    Background and study aims: Endoscopic ultrasound – guided celiac plexus block (EUS-CPB) is an established treatment for pain in patients with chronic pancreatitis (CP), but the effectiveness and safety of repeated procedures are unknown. Our objective is to report our experience of repeated EUS-CPB procedures within a single patient. , Patients and methods: A prospectively maintained EUS database was retrospectively analyzed to identify patients who had undergone more than one EUS-CPB procedure over a 17-year period. The main outcome measures included number of EUS-CPB procedures for each patient, self-reported pain relief, duration of pain relief, and procedure-related adverse events. , Results: A total of 248 patients underwent more than one EUS-CPB procedure and were included in our study. Patients with known or suspected CP (N = 248) underwent a mean (SD) of 3.1 (1.6) EUS-CPB procedures. In 76 % of the patients with CP, the median (range) duration of the response to the first EUS-CPB procedure was 10 (1 – 54) weeks. Lack of pain relief after the initial EUS-CPB was associated with failure of the next EUS-CPB (OR 0.17, 95 %CI 0.06 – 0.54). Older age at first EUS-CPB and pain relief after the first EUS-CPB were significantly associated with pain relief after subsequent blocks (P = 0.026 and P = 0.002, respectively). Adverse events included peri-procedural hypoxia (n = 2) and hypotension (n = 1) and post-procedural orthostasis (n = 2) and diarrhea (n = 4). No major adverse events occurred., Conclusions: Repeated EUS-CPB procedures in a single patient appear to be safe. Response to the first EUS-CPB is associated with response to subsequent blocks
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