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Found 37684 matches. Displaying 6141-6150
Deutsch-Feldman M, Picetti R, Seip-Cammack K, Zhou Y, Kreek MJ
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Effects of Handling and Vehicle Injections on Adrenocorticotropic and Corticosterone Concentrations in Sprague-Dawley Compared with Lewis Rats

JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE 2015 JAN; 54(1):35-39
The hypothalamic pituitary adrenal (HPA) axis is a key factor in the trajectory of the addiction-like cycle (a pattern of behavior characterized by escalating drug use, withdrawal, and relapse) in preclinical and clinical studies. Concentrations of HPA hormones change in laboratory animals in response to standard experimental procedures, including handling and vehicle injections. We compared HPA activity in adult male Lewis (inbred) and Sprague Dawley (outbred) rats, 2 common strains in rodent models of addiction, after different schedules of handling and saline injections, to explore the extent to which HPA responses differ by strain and whether interindividual differences underlie addiction vulnerability. The 4 treatment conditions were no, short, or long handling and saline injections. In handled groups, rats were handled for 1 to 2 min for 3 times daily and were euthanized after 7 d (short handling) or 14 d (long handling). The injection schedule in the saline injection group mimicked that in a model of binge-like cocaine exposure. Across all treatment groups, concentrations of adrenocorticotropic hormone were higher in Sprague Dawley than in Lewis rats. In Sprague Dawley rats, corticosterone concentrations decreased after continued handling but remained constant in Lewis rats. Interindividual variability in hormone levels was greater in Sprague Dawley than Lewis rats, although corticosterone variability decreased after continued handling. Prolactin did not differ between groups of either Sprague Dawley and Lewis rats before or after handling. This study underscores the importance of prolonged handling before experimenter-provided drug-administration paradigms and of strain-associated differences that may affect study outcomes.
Goulianos K
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RENORM Predictions of Diffraction at LHC Confirmed

DIFFRACTION 2014: INTERNATIONAL WORKSHOP ON DIFFRACTION IN HIGH-ENERGY PHYSICS 2015; 1654(?):?
The RENORM model predictions of diffractive, total, and total-inelastic cross sections at the LHC are confirmed by recent measurements. The predictions of several other available models are discussed, highlighting their differences from RENORM, mainly arising from the way rapidity gap formation, low- and high-mass diffraction, unitarization, and hadronization are implemented.
Li XC, Roberti R, Blobel G
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Structure of an integral membrane sterol reductase from Methylomicrobium alcaliphilum

NATURE 2015 JAN 1; 517(7532):104-U280
Sterols are essential biological molecules in the majority of life forms. Sterol reductases(1) including Delta(14)-sterol reductase (C14SR, also known as TM7SF2), 7-dehydrocholesterol reductase (DHCR7) and 24-dehydrocholesterol reductase (DHCR24) reduce specific carbon-carbon double bonds of the sterol moiety using a reducing cofactor during sterol biosynthesis. Lamin B receptor(2) (LBR), an integral inner nuclear membrane protein, also contains a functional C14SR domain. Here we report the crystal structure of a Delta(14)-sterol reductase (MaSR1) from the methanotrophic bacterium Methylomicro-bium alcaliphilum 20Z (a homologue of human C14SR, LBR and DHCR7) with the cofactor NADPH. The enzyme contains ten transmembrane segments (TM1-10). Its catalytic domain comprises the carboxy-terminal half (containing TM6-10) and envelops two interconnected pockets, one of which faces the cytoplasm and houses NADPH, while the other one is accessible from the lipid bilayer. Comparison with a soluble steroid 5 beta-reductase structure(3) suggests that the reducing end of NADPH meets the sterol substrate at the juncture of the two pockets. A sterol reductase activity assay proves that MaSR1 can reduce the double bond of a cholesterol biosynthetic intermediate, demonstrating functional conservation to human C14SR. Therefore, our structure as a prototype of integral membrane sterol reductases provides molecular insight into mutations in DHCR7 and LBR for inborn human diseases.
Andrews CD, Yueh YL, Spreen WR, St Bernard L, Boente-Carrera M, Rodriguez K, Gettie A, Russell-Lodrigue K, Blanchard J, Ford S, Mohri H, Cheng-Mayer C, Hong Z, Ho DD, Markowitz M
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A long-acting integrase inhibitor protects female macaques from repeated high-dose intravaginal SHIV challenge

SCIENCE TRANSLATIONAL MEDICINE 2015 JAN 14; 7(270):? Article 270ra4
Long-acting GSK1265744 (GSK744 LA) is a strand transfer inhibitor of the HIV/SIV (simian immunodeficiency virus) integrase and was shown to be an effective preexposure prophylaxis (PrEP) agent in a low-dose intrarectal SHIV (simian-human immunodeficiency virus) rhesus macaque challenge model. We examined the pharmacokinetics and efficacy of GSK744 LA as PrEP against repeat high-dose intravaginal SHIV challenge in female rhesus macaques treated with Depo-Provera (depot medroxyprogesterone acetate), which promotes viral transmission vaginally. When Depo-Provera-treated female rhesus macaques were dosed with GSK744 LA (50 mg/kg) monthly, systemic and tissue drug concentrations were lower than previously observed in male rhesus macaques. GSK744 concentrations were fivefold lower on average in cervical tissues than in rectal tissues. Eight female rhesus macaques were treated with GSK744 LA at week 0, and four female rhesus macaques served as controls. All animals received a high-dose challenge of SHIV162P3 at week 1. No infection was detected in GSK744 LA-treated rhesus macaques, whereas viremia was detected 1 to 2 weeks after SHIV challenge in all control animals. The GSK744 LA-treated rhesus macaques were given a second administration of drug at week 4 and further challenged at weeks 5 and 7. GSK744 LA treatment protected six of eight female rhesus macaques against three high-dose SHIV challenges, whereas all control animals became infected after the first challenge (P = 0.0003, log-rank test). These results support further clinical development of GSK744 LA for PrEP.
Galimidi RP, Klein JS, Politzer MS, Bai SY, Seaman MS, Nussenzweig MC, West AP, Bjorkman PJ
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Intra-Spike Crosslinking Overcomes Antibody Evasion by HIV-1

CELL 2015 JAN 29; 160(3):433-446
Antibodies developed during HIV-1 infection lose efficacy as the viral spike mutates. We postulated that anti-HIV-1 antibodies primarily bind monovalently because HIV's low spike density impedes bivalent binding through inter-spike crosslinking, and the spike structure prohibits bivalent binding through intra-spike crosslinking. Monovalent binding reduces avidity and potency, thus expanding the range of mutations permitting antibody evasion. To test this idea, we engineered antibody-based molecules capable of bivalent binding through intra-spike crosslinking. We used DNA as a "molecular ruler'' to measure intra-epitope distances on virion-bound spikes and construct intra-spike crosslinking molecules. Optimal bivalent reagents exhibited up to 2.5 orders of magnitude increased potency (>100-fold average increases across virus panels) and identified conformational states of virion-bound spikes. The demonstration that intra-spike crosslinking lowers the concentration of antibodies required for neutralization supports the hypothesis that low spike densities facilitate antibody evasion and the use of molecules capable of intra-spike crosslinking for therapy or passive protection.
Gitlin AD, Nussenzweig MC
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Fifty years of B lymphocytes

NATURE 2015 JAN 8; 517(7533):139-141
McEwen BS, Gray JD, Nasca C
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Recognizing resilience: Learning from the effects of stress on the brain.

Neurobiology of Stress 2015 JAN; 1(1):1-11
As the central organ of stress and adaptation to stressors, the brain plays a pivotal role in behavioral and physiological responses that may lead to successful adaptation or to pathophysiology and mental and physical disease. In this context, resilience can be defined as "achieving a positive outcome in the face of adversity". Underlying this deceptively simple statement are several questions; first, to what extent is this ability limited to those environments that have shaped the individual or can it be more flexible; second, when in the life course does the brain develop capacity for flexibility for adapting positively to new challenges; and third, can such flexibility be instated in individuals where early life experiences have limited that capacity? Brain architecture continues to show plasticity throughout adult life and studies of gene expression and epigenetic regulation reveal a dynamic and ever-changing brain. The goal is to recognize those biological changes that underlie flexible adaptability, and to recognize gene pathways, epigenetic factors and structural changes that indicate lack of resilience leading to negative outcomes, particularly when the individual is challenged by new circumstances. Early life experiences determine individual differences in such capabilities via epigenetic pathways and laying down of brain architecture that determine the later capacity for flexible adaptation or the lack thereof. Reactivation of such plasticity in individuals lacking such resilience is a new challenge for research and practical application. Finally, sex differences in the plasticity of the brain are often overlooked and must be more fully investigated.
Ott J
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Polygenic Models for Risk Prediction in Human Genetics

HUMAN HEREDITY 2015; 80(4):162-164
After a brief discussion and evaluation of Fisher's additive polygenic inheritance model, a few other approaches to polygenic inheritance are discussed, notably the polygenic threshold model. A literature review of applications of such models in human genetics is presented, and a simple approach, based on a finite polygenic model, is developed in detail. The fit of the model to recurrence risks in schizophrenia is discussed. (C) 2016 S. Karger AG, Basel
Juster RP, McEwen BS
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Sleep and chronic stress: new directions for allostatic load research

SLEEP MEDICINE 2015 JAN; 16(1):7-8
MacDuff DA, Reese TA, Kimmey JM, Weiss LA, Song C, Zhang X, Kambal A, Duan EN, Carrero JA, Boisson B, Laplantine E, Israel A, Picard C, Colonna M, Edelson BT, Sibley LD, Stallings CL, Casanova JL, Iwai K, Virgin HW
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Phenotypic complementation of genetic immunodeficiency by chronic herpesvirus infection

ELIFE 2015 JAN 22; 4(?):?
Variation in the presentation of hereditary immunodeficiencies may be explained by genetic or environmental factors. Patients with mutations in HOIL1 (RBCK1) present with amylopectinosis-associated myopathy with or without hyper-inflammation and immunodeficiency. We report that barrier-raised HOIL-1-deficient mice exhibit amylopectin-like deposits in the myocardium but show minimal signs of hyper-inflammation. However, they show immunodeficiency upon acute infection with Listeria monocytogenes, Toxoplasma gondii or Citrobacter rodentium. Increased susceptibility to Listeria was due to HOIL-1 function in hematopoietic cells and macrophages in production of protective cytokines. In contrast, HOIL-1-deficient mice showed enhanced control of chronic Mycobacterium tuberculosis or murine.-herpesvirus 68 (MHV68), and these infections conferred a hyper-inflammatory phenotype. Surprisingly, chronic infection with MHV68 complemented the immunodeficiency of HOIL-1, IL-6, Caspase-1 and Caspase-1; Caspase-11-deficient mice following Listeria infection. Thus chronic herpesvirus infection generates signs of auto-inflammation and complements genetic immunodeficiency in mutant mice, highlighting the importance of accounting for the virome in genotype-phenotype studies.