2,508 research outputs found

    ULTRASTRUCTURAL CHANGES IN THE MITOCHONDRIA OF CEREBELLAR PURKINJE CELLS OF NERVOUS MUTANT MICE

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    The maturation of cerebellar Purkinje cells of normal and nervous (nr/nr) mutant mice has been studied by light and electron microscopy. In the mutant, 90% of Purkinje cells selectively degenerate between postnatal days 23 and 50. Losses are greater in lateral than medial regions. Other cerebellar neurons appear normal. The first morphological abnormality recognized is the presence of rounded mitochondria in perikarya of some Purkinje cells of the mutant at 9 days after birth. By 15 days, all nr/nr Purkinje cells contain spherical mitochondria and begin to deviate from the normal maturational sequence. Elaboration of the extensive dendritic tree halts midway and newly formed axon collateral fibers degenerate. In the perikaryon, the basal polysomal accumulation and climbing fiber-somatic spine synapses are sometimes abnormally retained. Cisternae of the Golgi apparatus and rough endoplasmic reticulum cease to form aligned stacks, and decrease in number, while polysomes dissociate into free ribosomes. These changes are progressive, culminating in cell death. Although every nr/nr Purkinje cell demonstrates spherical mitochondria, some cells survive the critical period, retain a near-normal complement of organelles, and reacquire normal-appearing mitochondria. The disorder appears intrinsic to Purkinje cells since all major classes of synapses were identified before cell death

    A call for transparent reporting to optimize the predictive value of preclinical research

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    The US National Institute of Neurological Disorders and Stroke convened major stakeholders in June 2012 to discuss how to improve the methodological reporting of animal studies in grant applications and publications. The main workshop recommendation is that at a minimum studies should report on sample-size estimation, whether and how animals were randomized, whether investigators were blind to the treatment, and the handling of data. We recognize that achieving a meaningful improvement in the quality of reporting will require a concerted effort by investigators, reviewers, funding agencies and journal editors. Requiring better reporting of animal studies will raise awareness of the importance of rigorous study design to accelerate scientific progress

    Suppression of carrier induced ferromagnetism by composition and spin fluctuations in diluted magnetic semiconductors

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    We suggest an approach to account for spatial (composition) and thermal fluctuations in "disordered" magnetic models (e.g. Heisenberg, Ising) with given spatial dependence of magnetic spin-spin interaction. Our approach is based on introduction of fluctuating molecular field (rather than mean field) acting between the spins. The distribution function of the above field is derived self-consistently. In general case this function is not Gaussian, latter asymptotics occurs only at sufficiently large spins (magnetic ions) concentrations nin_i. Our approach permits to derive the equation for a critical temperature TcT_c of ferromagnetic phase transition with respect to the above fluctuations. We apply our theory to the analysis of influence of composition fluctuations on TcT_c in diluted magnetic semiconductors (DMS) with RKKY indirect spin-spin interaction.Comment: 6 pages, 2 figure

    As-built design specification for P1A software system modified display subsystem

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    This document contains the design of the proportional estimate processor which was written to satisfy the software requirement of Part A of the P1A experiment. The purposes of the project are: (1) to select the dots to be labelled; (2) to create tables of green numbers and brightness values for all selected dots per acquisition; (3) to create scatter plots of green numbers vs brightness for each acquisition for all selected dots. If labels have been provided then scatter plots of only categories of interest can be optionally produced; and (4) to produce trajectory plots of green number vs brightness at differing acquisition times for each dot. These plots need to be in the same order as the list of selected dots. When labels are provided only plots of dots of categories of interest are to be produced

    Inhibition of release of vasoactive and inflammatory mediators in airway and vascular tissues and macrophages by a Chinese herbal medicine formula for allergic rhinitis

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    Herbal therapies are being used increasingly for the treatment of allergic rhinitis. The aim of this study was to investigate the possible pharmacological actions and cellular targets of a Chinese herbal formula (RCM-101), which was previously shown to be effective in reducing seasonal allergic rhinitis symptoms in a randomized, placebo-controlled clinical trial. Rat and guinea pig isolated tissues (trachea and aorta) were used to study the effects of RCM-101 on responses to various mediators. Production of leukotriene 134 in porcine neutrophils and of prostaglandin E-2 and nitric oxide (NO) in Raw 264.7 cells were also measured. In rat and guinea pig tracheal preparations, RCM-101 inhibited contractile responses to compound 48/80 but not those to histamine (guinea pig preparations) or serotonin (rat preparations). Contractile responses of guinea pig tracheal preparations to carbachol and leukotriene C-4. and relaxant responses to substance P and prostaglandin E2 were not affected by RCM-101. In rat aortic preparations, precontracted with phenylephrine, endothelium-dependent relaxant responses to acetylcholine and endothelium-independent relaxant responses to sodium nitroprusside were not affected by RCM-101. However, RCM-101 inhibited relaxations to L-arginine in endothelium-denuded rat aortic preparations, which had been pre-incubated with lipopolysaccharide. RCM-101 did not affect leukotriene 134 formation in isolated porcine neutrophils, induced by the calcium ionophore A23187; however, it inhibited prostaglandin E-2 and NO production in lipopolysaccharide-stimulated murine macrophages (Raw 264.7 cells). The findings indicate that RCM-101 may have multiple inhibitory actions on the release and/or synthesis of inflammatory mediators involved in allergic rhinitis

    Assessing the Continuum of Care Pathway for Maternal Health in South Asia and Sub-Saharan Africa

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    We assess how countries in regions of the world where maternal mortality is highest - South Asia and Sub-Saharan Africa - are performing with regards to providing women with vital elements of the continuum of care
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