GPR34-mediated sensing of lysophosphatidylserine released by apoptotic neutrophils activates type 3 innate lymphoid cells to mediate tissue repair

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Computed tomography simulation with superquadrics

Accurate and efficient simulation of an x-ray transform for representative structures plays an important role in research and development of x-ray CT, for the evaluation and improvement of CT image reconstruction algorithms, in particular. Superquadrics are a family of three-dimensional objects, which can be used to model a variety of anatomical structures. In this paper, we propose an algorithm for the computation of x-ray transforms for superellipsoids and tori with a monochromatic x-ray. Their usefulness is demonstrated by projection and reconstruction of a superquadric-based thorax phantom. Our work indicates that superquadric modeling provides a more realistic visualization than quadratic modeling, and a faster computation than spline methods.     

Attenuation of intracavitary applicators in 192Ir-HDR brachytherapy

Unlike the penetrating monoenergetic 662 keV gamma rays emitted by 137Cs LDR sources, the spectrum of 192Ir used in HDR brachytherapy contains low-energy components. Since these are selectively absorbed by the high-atomic number materials of which intracavitary applicators are made, the traditional neglect of applicator attenuation can lead to appreciable dose errors. We investigated the attenuation effects of a uterine applicator, and of a set of commonly used vaginal cylinders. The uterine applicator consists of a stainless steel source guide tube with a wall thickness of 0.5 mm and a density of 8.02 g/cm3, whereas the vaginal cylinders consist of the same stainless steel tube plus concentric polysulfone cylinders with a radius of 1 or 2 cm and a density of 1.40 g/cm3. Monte Carlo simulations were performed to compute dose distributions for a bare 192Ir-HDR source, and for the same source located within the applicators. Relative measurements of applicator attenuation using ion-chambers (0.125 cm3) confirmed the Monte Carlo results within 0.5%. We found that the neglect of the applicator attenuation overestimates the dose along the transverse plane by up to 3.5%. At oblique angles, the longer photon path within applicators worsens the error. We defined attenuation-corrected radial dose and anisotropy functions, and applied them to a treatment having multiple dwell positions inside a vaginal cylinder.     

化合物构效关系的模糊极小极大神经网络识别研究

应用模糊极小极大神经网络研究了化合物复杂结构和性能（QSAR）之间的关系，用该法进行几组化合物致癌的识别，结果优于线性回归的方法，对此作出一些分析。     

血管内皮损伤标志物在2型糖尿病患者中的变化

目的:探讨2型糖尿病(DM)患者血管内皮损伤标志物的变化。方法:分别测定89例2型DM患者和76例正常对照者血浆可溶性血管内皮细胞蛋白C受体(sEPCR),血管性血友病因子(v WF)和可溶性血栓调节蛋白(sTM),并测定DM患者24h尿白蛋白排泄(UAE),根据尿UAE水平和病程分组进行比较分析。结果:2型DM患者血浆sEPCR、v WF及sTM水平高于正常对照组(P<0.05),并且与其尿UAE水平和病程呈显著正相关。结论:血浆sEPCR、v WF及sTM水平可作为观察2型DM并发血管病变以及严重程度的指标。     

Early-life epileptiform discharges exert both rapid and long-lasting effects on AMPAR subunit composition and distribution in developing neurons

The perinatal period of brain is characterized by dynamic changes in structure and high propensity for epilepsy. Animal models have shown that alterations of AMPA receptor (AMPAR) assembly or function may be related to seizure-induced cell damage, long-lasting impairments in brain development and seizure threshold. However, effects of earlier epileptiform discharges on AMPAR composition and sub-cellular distribution remain understudied. In this study, we analyzed age-dependent variation of relative GluR1 and GluR2 protein levels in primary cultured rat cortical neurons at 7 DIV, 12 DIV, 17 DIV and 21 DIV. By inducing a single event of epileptiform activity at 6 DIV, we tested the effects of early-life seizure-like insults on AMPAR subunit distribution. We found a significant increase in synaptosomal membrane GluR1 expression in magnesium-free (MGF) medium-treated neurons at each time point detected (p < 0.05), while GluR2 expression increased at 7 DIV, and declined at 17 DIV and 21 DIV respectively (p < 0.05). That is, a trend of high GluR1 with much lower GluR2 expression on the surface membrane of epileptiform discharges experienced neurons over time in culture was presented. These findings in an in vitro model of early-life seizure may inform rodent models of epilepsy, as well as the cellular mechanism involved in epilepsy-associated brain dysfunction.     

Immunofluorescent evidence for exocytosis and internalization of secretory granule membrane in isolated chromaffin cells

Cultured bovine adrenal medullary chromaffin cells were stimulated with the secretogogues Ba2+ or carbamyl choline plus Ca2+ in the presence of a monospecific rabbit IgG fraction directed against bovine dopamine beta-hydroxylase. The anti-dopamine beta-hydroxylase was labeled either with fluorescent protein A or with a fluorescent second antibody to rabbit IgG. Stimulation produced a patchy cell surface distribution of fluorescence. There was no noticeable internalization of the fluorescence for up to 2 h. In similar experiments using fluorescent monovalent fragments (Fab) of the same monospecificidopamine-beta-hydroxylase IgG, a more uniform distribution of the fluorescence was observed. A few min after a 5 min period of stimulation with Ba2+, the fluorescence appeared to be on or near the cell surface; however, after 20 min or more it was distributed throughout the cytoplasm except that the cell nuclei were not labeled. Thus, dopamine beta-hydroxylase which appeared on the cell surface as a consequence of exocytosis was internalized in the presence of monovalent antibody fragments, but not in the presence of the divalent (polyclonal) antibody, presumably because endocytosis of dopamine beta-hydroxylase was inhibited by crosslinking of the dopamine beta-hydroxylase molecules. The internalized anti-dopamine beta-hydroxylase Fab fragments were found to reappear on the cell surface during a second secretory response. It is concluded that the interior of the chromaffin granule membrane, for which dopamine beta-hydroxylase is a marker, becomes exposed on the surface of the cell during secretion and that the membrane is then retrieved back into the cell where it can be re-used in a further secretory cycle.     

阿尔茨海默病、阿尔茨海默病混合型及血管性痴呆患者心理及行为症状的比较

目的 比较阿尔茨海默病(Alzheimer Disease，AD)、AD混合型痴呆(Mixed dementia，MD)、血管性痴呆(Vascular dementia，VD)心理和行为症状(Psychological and behavioral symptoms of dementia，PBSD)的特征。方法 AD、MD及VD患者各30名参加本研究。采用Alzheimer病行为症状评定量表(The Begavioral Pathlolgy in Alzheiner Disease Rating Scale，BEHAVE—AD)、Cohen—Masfield激惹性问卷(The Cohen Mansfield Agitation Inventory，CMAI)评定痴呆患者BPSD。结果 AD患者激惹、焦虑与恐惧发生率较高，VD患者无目的游荡发生率、严重程度较低，MD患者BPSD症状无特异性。结论 AD、VD患者BPSD症状有特异性，MD患者BPSD表现无特异性。     

抗蜱免疫研究Ⅱ.宿主被中华硬蜱叮咬后其血液和局部组织中组胺含量的动态分析

本文选用微量组胺测定技术，对中华硬蜱（Ｉｘｏｄｅｓｓｉｎｅｎｓｉｓ）雌性成虫叮咬初次和再次感染宿主（家兔）血液和局部皮肤组织中组胺含量进行测定。研究结果表明：中华硬蜱初次叮咬家兔后吸血量２３３．７８±４０．５３ｍｇ，宿主血液和局部组织中组胺含量第５天达高峰，分别为４０５．４４±１２０．２９ｎｇ／ｍｌ和３６２．３４±８４．７２ｎｇ／ｇ，而中华硬蜱再次叮咬感染组家兔吸血量为９６．４２±３６．２８ｍｇ，宿主血液和局部组织中组胺迅速升高，２４小时达高峰，分别为６４２．４３±１４６．４７ｎｇ／ｍｌ和１１５２．５３±２０３．９６ｎｇ／ｇ，与初次叮咬组胺含量相比有显著性差异（Ｐ＜０．０１）。提示组胺与宿主产生对蜱感染的获得性抵抗力有关。