887 research outputs found

    Multiple Haemangiomas, Diaphragmatic Eventration and Beckwith-Wiedemann Syndrome: An Unusual Association

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    A 6-month-old girl with Beckwith-Wiedemann syndrome, multiple haemangiomas (axillary, laryngeal, pulmonary and hepatic) and diaphragmatic eventration was reported. All tumours responded to treatment with propranolol. The surgical correction of diaphragmatic eventration was crucial to a better outcome

    Comparison of cytosolic Ca 2+ and exocytosis responses from single rat and bovine chromaffin cells

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    The relationship between cytosolic Ca2+ and catecholamine secretion during stimulus-secretion coupling has been examined at individual chromaffin cells isolated from the cow and rat. Vesicular catecholamine exocytosis was determined via amperometric measurements with carbon fiber microelectrodes and fura-2 was used for simultaneous fluorescent monitoring of cytosolic Ca2+ at the same cell.12 Individual secretory vesicles in cells from the two species were found to release similar amounts of catecholamine. In addition, the time courses for secretion from individual vesicles was similar with rat and bovine chromaffin cells. The total quantity of catecholamine released and the change in cytosolic Ca2+ were also similar in response to exposure to K+ (60 mM), DMPP (50 uM), and histamine (50 uM), although both responses were more prolonged following DMPP and histamine at bovine cells. Agents that mobilize intracellular Ca2+-stores such as methacholine, caffeine and bradykinin resulted in different cytosolic Ca2+ and exocytosis responses at the rat and bovine chromaffin cells. Results indicates a heightened Ca2+ store activity or a more filled state in chromaffin cells from the rat. The results of this study clearly show that single cell techniques can be used to characterize stimulus-secretion coupling. The requirement for lower numbers of cells with these techniques means that chromaffin cells from rodents can be routinely employed. This can be advantageous to minimize biological variability21 which occurs with organs obtained from slaughter houses and enables the investigation of genetically-altered animals

    Analytical and numerical analyses of the micromechanics of soft fibrous connective tissues

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    State of the art research and treatment of biological tissues require accurate and efficient methods for describing their mechanical properties. Indeed, micromechanics motivated approaches provide a systematic method for elevating relevant data from the microscopic level to the macroscopic one. In this work the mechanical responses of hyperelastic tissues with one and two families of collagen fibers are analyzed by application of a new variational estimate accounting for their histology and the behaviors of their constituents. The resulting, close form expressions, are used to determine the overall response of the wall of a healthy human coronary artery. To demonstrate the accuracy of the proposed method these predictions are compared with corresponding 3-D finite element simulations of a periodic unit cell of the tissue with two families of fibers. Throughout, the analytical predictions for the highly nonlinear and anisotropic tissue are in agreement with the numerical simulations

    Closely related Lak megaphages replicate in the microbiomes of diverse animals

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    Lak phages with alternatively coded ∼540 kbp genomes were recently reported to replicate in Prevotella in microbiomes of humans that consume a non-western diet, baboons and pigs. Here, we explore Lak phage diversity and broader distribution using diagnostic PCR and genome-resolved metagenomics. Lak phages were detected in 13 animal types, including reptiles, and are particularly prevalent in pigs. Tracking Lak through the pig gastrointestinal tract revealed significant enrichment in the hindgut compared to the foregut. We reconstructed 34 new Lak genomes, including six curated complete genomes, all of which are alternatively coded. An anomalously large (∼660 kbp) complete genome reconstructed for the most deeply branched Lak from a horse microbiome is also alternatively coded. From the Lak genomes, we identified proteins associated with specific animal species; notably, most have no functional predictions. The presence of closely related Lak phages in diverse animals indicates facile distribution coupled to host-specific adaptation

    The Threshold Bias Model: A Mathematical Model for the Nomothetic Approach of Suicide

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    Comparative and predictive analyses of suicide data from different countries are difficult to perform due to varying approaches and the lack of comparative parameters.A simple model (the Threshold Bias Model) was tested for comparative and predictive analyses of suicide rates by age. The model comprises of a six parameter distribution that was applied to the USA suicide rates by age for the years 2001 and 2002. Posteriorly, linear extrapolations are performed of the parameter values previously obtained for these years in order to estimate the values corresponding to the year 2003. The calculated distributions agreed reasonably well with the aggregate data. The model was also used to determine the age above which suicide rates become statistically observable in USA, Brazil and Sri Lanka.The Threshold Bias Model has considerable potential applications in demographic studies of suicide. Moreover, since the model can be used to predict the evolution of suicide rates based on information extracted from past data, it will be of great interest to suicidologists and other researchers in the field of mental health
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