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Found 37684 matches. Displaying 5831-5840
Sharma VK, Pai G, Deswarte C, Lodha R, Singh S, Kang LW, Yin CC, Casanova JL, Bustamante J, Kabra SK
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Disseminated Mycobacterium avium Complex Infection in a Child with Partial Dominant Interferon Gamma Receptor 1 Deficiency in India

JOURNAL OF CLINICAL IMMUNOLOGY 2015 JUL; 35(5):459-462
Mendelian susceptibility to mycobacterial disease (MSMD) is a rare condition characterized by clinical disease caused by weakly virulent mycobacteria. All genes mutated in MSMD patients are involved in IFN-gamma immunity. Autosomal partial dominant (PD) interferon-gamma receptor 1 (IFN-gamma R1) deficiency is the most frequent abnormality affecting the group of MSMD patients leading to impaired response of IFN-gamma. We describe here a patient from India with disseminated infection due to Mycobacterium avium intracellulare (MAC) including multifocal osteomyelitis and BCG disease. A heterozygous mutation in exon 6 of IFNGR1 gene was identified, conferring an autosomal PD IFN-gamma R1 deficiency. Patient had recurrence of mycobacterial disease during antibiotic therapy for which subcutaneous IFN-gamma was added as a modality of treatment for resistant MAC infection.
Gadelha C, Zhang WZ, Chamberlain JW, Chait BT, Wickstead B, Field MC
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Architecture of a Host-Parasite Interface: Complex Targeting Mechanisms Revealed Through Proteomics

MOLECULAR & CELLULAR PROTEOMICS 2015 JUL; 14(7):1911-1926
Surface membrane organization and composition is key to cellular function, and membrane proteins serve many essential roles in endocytosis, secretion, and cell recognition. The surface of parasitic organisms, however, is a double-edged sword; this is the primary interface between parasites and their hosts, and those crucial cellular processes must be carried out while avoiding elimination by the host immune defenses. For extracellular African trypanosomes, the surface is partitioned such that all endo-and exocytosis is directed through a specific membrane region, the flagellar pocket, in which it is thought the majority of invariant surface proteins reside. However, very few of these proteins have been identified, severely limiting functional studies, and hampering the development of potential treatments. Here we used an integrated biochemical, proteomic and bioinformatic strategy to identify surface components of the human parasite Trypanosoma brucei. This surface proteome contains previously known flagellar pocket proteins as well as multiple novel components, and is significantly enriched in proteins that are essential for parasite survival. Molecules with receptor-like properties are almost exclusively parasite-specific, whereas transporter-like proteins are conserved in model organisms. Validation shows that the majority of surface proteome constituents are bona fide surface-associated proteins and, as expected, most present at the flagellar pocket. Moreover, the largest systematic analysis of trypanosome surface molecules to date provides evidence that the cell surface is compartmentalized into three distinct domains with free diffusion of molecules in each, but selective, asymmetric traffic between. This work provides a paradigm for the compartmentalization of a cell surface and a resource for its analysis.
Markowitz M, Meyers K
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Extending access with long-acting antiretroviral therapy: the next advance in HIV-1 therapeutics and prevention

CURRENT OPINION IN HIV AND AIDS 2015 JUL; 10(4):216-218
Zeng WW, Lu YH, Lee J, Friedman JM
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Reanalysis of parabiosis of obesity mutants in the age of leptin

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2015 JUL 21; 112(29):E3874-E3882
In this study we set out to explain the differing effects of parabiosis with genetically diabetic (db) mice versus administration of recombinant leptin. Parabiosis of db mutant, which overexpress leptin, to wildtype (WT) or genetically obese (ob) mice has been reported to cause death by starvation, whereas leptin infusions do not produce lethality at any dose or mode of delivery tested. Leptin is not post-translationally modified other than a single disulphide bond, raising the possibility that it might require additional factor(s) to exert the maximal appetite-suppressing effect. We reconfirmed the lethal effect of parabiosis of db mutant on WT mice and further showed that this lethality could not be rescued by administration of ghrelin or growth hormone. We then initiated a biochemical fractionation of a high-molecular-weight leptin complex from human plasma and identified clusterin as a major component of this leptin-containing complex. However, in contrast to previous reports, we failed to observe a leptin-potentiating effect of either exogenous or endogenous clusterin, and parabiosis of db clusterin(-/-) double-mutant to WT mice still caused lethality. Intriguingly, in parabiotic pairs of two WT mice, leptin infusion into one of the mice led to an enhanced starvation response during calorie restriction as evidenced by increased plasma ghrelin and growth-hormone levels. Moreover, leptin treatment resulted in death of the parabiotic pairs. These data suggest that the appetite suppression in WT mice after parabiosis to db mutants is the result of induced hyperleptinemia combined with the stress or other aspect(s) of the parabiosis procedure.
Srimathveeravalli G, Silk M, Wimmer T, Monette S, Kimm S, Maybody M, Solomon SB, Coleman J, Durack JC
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Feasibility of Catheter-Directed Intraluminal Irreversible Electroporation of Porcine Ureter and Acute Outcomes in Response to Increasing Energy Delivery

JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY 2015 JUL; 26(7):1059-1066
Purpose: To evaluate the feasibility of focal intraluminal irreversible electroporation (IRE) in the ureter with a novel electrode catheter and to study the treatment effects in response to increasing pulse strength. Materials and Methods: Five IRE treatment settings were each evaluated twice for the ablation of normal ureter in 5 Yorkshire pigs (n = 1-4 ablations per animal; total of 10 ablations) with the use of a prototype device under ultrasound and fluoroscopic guidance. Animals received unilateral or bilateral treatment, limited to a maximum of 2 ablations in any 1 ureter. Treatment was delivered with increasing pulse strength (from 1,000 V to 3,000 V in increments of 500 V) while keeping the pulse duration (100 mu s) and number of pulses (n = 90) constant. Ureter patency was assessed with antegrade ureteropyelography immediately following treatment. Animals were euthanized within 4 hours after treatment, and treated urinary tract was harvested for histopathologic analysis with hematoxylin and eosin and Masson trichrome stains. Results: IRE was successfully performed in all animals, without evidence of ureteral perforation. Hematoxylin and eosin analysis of IRE treatments demonstrated full-thickness ablation at higher field strengths (mucosa to the adventitia). Masson trichrome stains showed preservation of connective tissue at all field strengths. Conclusions: Intraluminal catheter-directed IRE ablation is feasible and produces full-thickness ablation of normal ureters. There was no evidence of lumen perforation even at the maximum voltages evaluated.
Sultanik P, Mallet V, Lagaye S, Casrouge A, Dorival C, Barthe Y, Fontaine H, Hezode C, Mottez E, Bronowicki JP, Carrat F, Theodorou I, Abel L, Gayat E, Fontanet A, Pol S, Albert ML
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Plasma apolipoprotein H limits HCV replication and associates with response to NS3 protease inhibitors-based therapy

LIVER INTERNATIONAL 2015 JUL; 35(7):1833-1844
Background & AimsChronic infection with HCV remains a public health problem with approximately 150 million people infected worldwide. HCV intersects with lipid metabolism for replication and entry; and plasma concentrations of apolipoproteins have been identified as predictors for response to therapy. Herein, we conducted a screen of plasma proteins, including all apolipoproteins, to identify correlates of response to pegylated-interferon/ribavirin (PR) and HCV non-structural protein 3 (NS3) inhibitors (i.e., telaprevir/boceprevir) therapy in treatment-experienced cirrhotic patients from the ANRS CUPIC cohort. MethodsWe analysed 220 baseline plasma protein concentrations in 189 patients using Luminex technology and analyzed results. ResultsWe identified baseline levels of apolipoprotein H (apoH) as a surrogate marker for sustained virological response (SVR). Notably, increased plasma concentration of apoH, used in combination with known clinical parameters, established a robust model with improved classification of patients as likely to achieve SVR (AUC=0.77, Se=66%, Sp=72%, NRI=39%). Moreover, we provide mechanistic information that indicates a previously unidentified role for apoH during viral entry. Using a human liver slices HCV infection model, we demonstrate that apoH limits replication. ConclusionThese data support testing of new biomarker strategies for the management of cirrhotic HCV patients and expand our understanding of how apoH may intersect with HCV infection.
Solovey G, Alonso LM, Yanagawa T, Fujii N, Magnasco MO, Cecchi GA, Proekt A
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Loss of Consciousness Is Associated with Stabilization of Cortical Activity

JOURNAL OF NEUROSCIENCE 2015 JUL 29; 35(30):10866-10877
What aspects of neuronal activity distinguish the conscious from the unconscious brain? This has been a subject of intense interest and debate since the early days of neurophysiology. However, as any practicing anesthesiologist can attest, it is currently not possible to reliably distinguish a conscious state from an unconscious one on the basis of brain activity. Here we approach this problem from the perspective of dynamical systems theory. We argue that the brain, as a dynamical system, is self-regulated at the boundary between stable and unstable regimes, allowing it in particular to maintain high susceptibility to stimuli. To test this hypothesis, we performed stability analysis of high-density electrocorticography recordings covering an entire cerebral hemisphere in monkeys during reversible loss of consciousness. We show that, during loss of consciousness, the number of eigenmodes at the edge of instability decreases smoothly, independently of the type of anesthetic and specific features of brain activity. The eigenmodes drift back toward the unstable line during recovery of consciousness. Furthermore, we show that stability is an emergent phenomenon dependent on the correlations among activity in different cortical regions rather than signals taken in isolation. These findings support the conclusion that dynamics at the edge of instability are essential for maintaining consciousness and provide a novel and principled measure that distinguishes between the conscious and the unconscious brain.
Flores-Montoya MG, Alvarez JM, Sobin C
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Olfactory recognition memory is disrupted in young mice with chronic low-level lead exposure

TOXICOLOGY LETTERS 2015 JUL 2; 236(1):69-74
Chronic developmental lead exposure yielding very low blood lead burden is an unresolved child public health problem. Few studies have attempted to model neurobehavioral changes in young animals following very low level exposure, and studies are needed to identify tests that are sensitive to the neurobehavioral changes that may occur. Mechanisms of action are not yet known however results have suggested that hippocampus/dentate gyrus may be uniquely vulnerable to early chronic low-level lead exposure. This study examined the sensitivity of a novel odor recognition task to differences in preadolescent C57BL/6J mice chronically exposed from birth to PND 28, to 0 ppm (control), 30 ppm (lowdose), or 330 ppm (higher-dose) lead acetate (N = 33). Blood lead levels (BLLs) determined by ICP-MS ranged from 0.02 to 20.31 mu g/dL. Generalized linear mixed model analyses with litter as a random effect showed a significant interaction of BLL x sex. As BLLs increased olfactory recognition memory decreased in males. Among females, non-linear effects were observed at lower but not higher levels of lead exposure. The novel odor detection task is sensitive to effects associated with early chronic low-level lead exposure in young C57BL/6J mice. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
Novick DM, Salsitz EA, Joseph H, Kreek MJ
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Methadone Medical Maintenance: An Early 21st-Century Perspective

JOURNAL OF ADDICTIVE DISEASES 2015 JUL 3; 34(2-3):226-237
Methadone medical maintenance is the treatment of stable methadone-maintained patients in primary care physicians' offices under an exemption from federal methadone regulations. Reports from seven such programs in six states show high retention and low frequencies of illicit drug use. Patients and physicians indicate high levels of satisfaction. Although methadone maintenance has a long history of safety and efficacy, most methadone medical maintenance programs are no longer operating or accepting new patients. Federal regulations for standard methadone clinics allow some features of methadone medical maintenance, and advocacy for state approval of these changes is strongly recommended.
Rickman KA, Lach FP, Abhyankar A, Donovan FX, Sanborn EM, Kennedy JA, Sougnez C, Gabriel SB, Elemento O, Chandrasekharappa SC, Schindler D, Auerbach AD, Smogorzewska A
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Deficiency of UBE2T, the E2 Ubiquitin Ligase Necessary for FANCD2 and FANCI Ubiquitination, Causes FA-T Subtype of Fanconi Anemia

CELL REPORTS 2015 JUL 7; 12(1):35-41
Fanconi anemia (FA) is a rare bone marrow failure and cancer predisposition syndrome resulting from pathogenic mutations in genes encoding proteins participating in the repair of DNA interstrand crosslinks (ICLs). Mutations in 17 genes (FANCA-FANCS) have been identified in FA patients, defining 17 complementation groups. Here, we describe an individual presenting with typical FA features who is deficient for the ubiquitin-conjugating enzyme (E2), UBE2T. UBE2T is known to interact with FANCL, the E3 ubiquitin-ligase component of the multiprotein FA core complex, and is necessary for the monoubiquitination of FANCD2 and FANCI. Proband fibroblasts do not display FANCD2 and FANCI monoubiquitination, do not form FANCD2 foci following treatment with mitomycin C, and are hypersensitive to crosslinking agents. These cellular defects are complemented by expression of wild-type UBE2T, demonstrating that deficiency of the protein UBE2T can lead to Fanconi anemia. UBE2T gene gains an alias of FANCT.