1,562 research outputs found

    In immune defense: redefining the role of the immune system in chronic disease

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    The recognition of altered immune system function in many chronic disease states has proven to be a pivotal advance in biomedical research over the past decade. For many metabolic and mood disorders, this altered immune activity has been characterized as inflammation, with the attendant assumption that the immune response is aberrant. However, accumulating evidence challenges this assumption and suggests that the immune system may be mounting adaptive responses to chronic stressors. Further, the inordinate complexity of immune function renders a simplistic, binary model incapable of capturing critical mechanistic insights. In this perspective article, we propose alternative paradigms for understanding the role of the immune system in chronic disease. By invoking allostasis or systems biology rather than inflammation, we can ascribe greater functional significance to immune mediators, gain newfound appreciation of the adaptive facets of altered immune activity, and better avoid the potentially disastrous effects of translating erroneous assumptions into novel therapeutic strategies

    Differential Endogenous Estrogen Exposure Influences Prefrontal Cortex Response to Acute Stress

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    The present study was conducted to determine the effect of differential endogenous estrogen exposure in rats on stress-induced changes in spatial working memory. Subjects comprised male (n=8) and female (n=10) Sprague-Dawley rats, which were trained to complete a T maze, delayed alternation task. Performance was scored as a percentage of trials during which the correct maze arm was selected. Subjects scores were recorded after 1 and 2 hours of restraint stress, as well as after 1 hour of unimpeded movement in a cage placed in the testing room. Restraint stress was effected through physical confinement within plastic, cylindrical tubing. Female subjects underwent each of the testing conditions twice, during periods of high and low endogenous estrogen exposure, as ascertained by microscopic examination of vaginal epithelial cells for estrous cycle stage determination. Females in proestrus (elevated endogenous estrogen exposure) subjected to 1 hour of restraint performed significantly worse than their baseline scores (p=0.0017) or females in estrus (low endogenous estrogen exposure) after 1 hour of restraint (p=0.00014). After 1 hour of restraint, females in proestrus also committed an increased rate of perseverative errors compared to females in estrus, although this increase did not achieve statistical significance (p=0.06). No appreciable differences existed among subject groups in baseline performance or subsequent to 2 hours of restraint stress. Resultant data indicate impaired working memory among female rats under conditions of stress in the context of elevated endogenous estrogen exposure. This study, then, suggests a potential synergistic effect of stress and estrogen in compromising prefrontal cortex function and, therefore, may lend insight into the observed sex-related disparity in the incidence of major depressive disorder and other anxiety-related mood disorders

    Sounds in the neighborhood : a curriculum for six and seven year olds

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    This study of the sounds in the neighborhood comes from a larger neighborhood study within the first grade class. Students will have the opportunity to gain more information about the neighborhood by solely listening to the sounds and making sense of these sounds

    The facilitated diffusion of oxygen by hemoglobin and myoglobin

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    We have clarified the use of Wyman's differential equation for the facilitated oxygen flux through a slab of solution of myoglobin or hemoglobin by showing that there is a unique choice of boundary condition on the carrier concentration to be employed in conjunction with it. The singular perturbation solution of Wyman's equation, due to Murrayand Mitchell and Murray, has been extended. By means of it, the paradox of Wittenberg, that the facilitated oxygen flux per mole of heme is apparently independent of the protein carrier, has been resolved

    Compulsory State Insurance of Workingmen

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    Predictors of premenstrual impairment among women undergoing prospective assessment for premenstrual dysphoric disorder: a cycle-level analysis

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    Background Women who experience significant premenstrual symptoms differ in the extent to which these symptoms cause cyclical impairment. This study clarifies the type and number of symptoms that best predict premenstrual impairment in a sample of women undergoing prospective assessment for premenstrual dysphoric disorder (PMDD) in a research setting. Central research goals were to determine (1) which emotional, psychological, and physical symptoms of PMDD are uniquely associated with premenstrual impairment, and (2) how many cyclical symptoms optimally predict the presence of a clinically significant premenstrual elevation of impairment. Method A total of 267 naturally cycling women recruited for retrospective report of premenstrual emotional symptoms completed daily symptom reports using the Daily Record of Severity of Problems (DRSP) and occupational, recreational, and relational impairment for 1–4 menstrual cycles ( N = 563 cycles). Results Multilevel regression revealed that emotional, psychological, and physical symptoms differ in their associations with impairment. The core emotional symptoms of PMDD were predictors of impairment, but not after accounting for secondary psychological symptoms, which were the most robust predictors. The optimal number of premenstrual symptoms for predicting clinically significant premenstrual impairment was four. Conclusion Results enhance our understanding of the type and number of premenstrual symptoms associated with premenstrual impairment among women being evaluated for PMDD in research contexts. Additional work is needed to determine whether cognitive symptoms should receive greater attention in the study of PMDD, and to revisit the usefulness of the five-symptom diagnostic threshold

    Semi-classical Green kernel asymptotics for the Dirac operator

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    We consider a semi-classical Dirac operator in arbitrary spatial dimensions with a smooth potential whose partial derivatives of any order are bounded by suitable constants. We prove that the distribution kernel of the inverse operator evaluated at two distinct points fulfilling a certain hypothesis can be represented as the product of an exponentially decaying factor involving an associated Agmon distance and some amplitude admitting a complete asymptotic expansion in powers of the semi-classical parameter. Moreover, we find an explicit formula for the leading term in that expansion.Comment: 46 page
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