Strategies of hemopoietic stress adaptation within the medullary cavity

Gravimetric determination of total bone water space was used as an index of available bone marrow space in mice following various specific stressors, i.e., splenectomy, hypoxia, bone fracture, and estrone-induced osteosclerosis. Data was corrected for bone weight and was reported as specific bone marrow volume (total bone water space/mg dry bone X 100). A direct relationship was observed between specific bone marrow volume and medullary hemopoietic activity induced by stress. Absolute and/or relative marrow space increased following splenectomy, hypoxia, and fracture. Osteosclerotic animals shift most hemopoietic activity from marrow to spleen, and splenectomized osteosclerotic animals become anemic. Both intact and splenectomized hypoxic animals develop increased specific bone marrow volume and successfully compensate for hypoxia with enhanced erythropoiesis. Animals sustaining a fracture callus increase both specific bone marrow volume and hemopoietic activity at the callus without an increase in hemopoietic demand. Increased specific bone marrow volume extends the marrow bone interface, where primitive stem cells accumulate, while expanding marrow stromal space, where stem cells lodge, proliferate and differentiate. Therefore, it would appear that availability of competent marrow space may play an integral part in passively permitting hematopoiesis and in determining hemopoietic reserve capacity. Stem cell migration increases during intensified hemopoietic demand, which also may be related to available marrow space. Mice have a low medullary hemopoietic reserve capacity; subsequently, when available medullary hematopoietic stroma becomes occupied, stem cells are more likely to migrate from the marrow to extra-medullary sites where they mature before entering the circulating pool.     

Increased fluidity of Plasmodium berghei-infected mouse red blood cell membranes detected by electron spin resonance spectroscopy

The fluidity of Plasmodium berghei-infected mouse red cell membranes is increased over that of uninfected cells at both 24°C and 37°C. This was demonstrated by electron spin resonance spectroscopy using the hydrocarbon spin labels 2-dodecyl-2′,5,5′-trimethyloxazolidine-N-oxyl and 2-heptyl-2′ -hexyl-5,5′-dimethyloxazolidine-N-oxyl to label regions of the bilayer near its surface, and deeper within the hydrocarbon region, respectively. Arrhenius plots of the ‘empirical motion parameter’ (R_i) obtained from 2-heptyl-2′-hexyl-5,5′-dimethyloxazolidine-N-oxyl-labeled cells versus temperature over the range from 0 to 45°C showed an hysteretic behavior of the spin labels in the membranes of both mature and immature uninfected cells. Such hysteretic behavior was consistently lacking in membranes of infected cells. These differences in membrane fluidity and spin label behavior are interpreted to reflect biochemical modifications of the red cell membrane which occur with infection by the malarial parasite.     

A second locus (GLC3B) for primary congenital glaucoma (Buphthalmos) maps to the 1p36 region

Primary congenital glaucoma (gene symbol: GLC3) is an ocular disorder that occurs for 0.01-0.04% of blind people. In the majority of familial cases reported so far, this condition is inherited as an autosomal recessive trait. We have recently used a group of 17 GLC3 families with a minimum of two affected offspring and consanguinity in most of the parental generation and mapped the first GLC3 locus (GLC3A) to the 2p21 region. Six families did not show any linkage to the GLC3A locus and thus provided evidence for genetic heterogeneity of this disorder. A total of eight families unlinked to the 2p21 region were used to search for the chromosomal location of the second GLC3 locus. Herein, we describe mapping of a new locus (designated GLC3B) for primary congenital glaucoma to the short arm of chromosome 1 (1p36.2-36.1) that is situated centromeric to the neuroblastoma and Charcot-Marie-Tooth type 2A (CMT2A) loci. A total of 17 DNA markers were genotyped from this region of chromosome 1. Four families showed no recombination with the two markers D1S2834 and D1S402 with a maximum lod score of 4.510 and 4.157 respectively. Pairwise and multipoint linkage analysis and inspection of the haplotypes revealed that the remaining four families are not linked to this part of chromosome 1, thus providing further evidence that at least one more locus for the autosomal recessive form of GLC3 must exist in the genome. Based on the recombination events, the overall linkage map of this region is: tel-D1S1192-D1S1635-D1S1193 - (D1S1597/-D1S489/D1S228)- [GLC3B/D1S2834/D1S402] - (D1S1176/D1S507/D1S407) - D1S2728-(MFAP2/D1S170) - D1S1368 - D1S436- D1S1592-cen.      

评“McCall观察方法”——对一种色谱系统分配效果观察方法的商榷

本文通过理论分析和文献数据的分析,对McCall提出的色谱系统分配效果的观察方法提出了不同的看法,认为McCall方法中的所谓logK并不是常数。McCall的方法无论在理论上和实践上都是不妥的。     

美国医保支付制度改革对我国康复护理服务的启示

梳理了美国医保支付制度改革进程,总结了捆绑支付模式内涵及其对康复护理服务的影响。结合我国国情,借鉴美国医保支付制度改革经验,认为我国应建立基于价值评价的康复护理服务医保支付制度,充分发挥医保基金的引导和保障作用,健全多元化的复合型医保支付体系,创建“以人民的健康为中心”的连续型医疗服务保障体系。     

2015—2020年南通市中小学生食源性疾病特征分析

目的 分析南通市中小学生食源性疾病流行病学特征,为有效防控中小学生食源性疾病提供科学依据。方法 收集2015—2020年南通市哨点医院就诊的中小学生食源性疾病病例信息,并采集病例粪便标本进行病原体检测,运用χ²检验比较不同学段中小学生食源性疾病病例的分布。结果 共监测中小学生食源性疾病病例1 432例。不同可疑暴露食品的分类和进食场所的病例数有统计学差异（χ²= 73.421;χ² = 66.857,P均＜0.001）,可疑暴露食品主要为肉与肉制品（28.21%）和水产动物及其制品（17.86%）,可疑进食场所主要为家庭（57.60%）和学校食堂（12.69%）。疑似食源性疾病暴发事件主要发生在学校食堂。共采集标本214份,检出病原体22份,总体检出率为10.28%,阳性病原体以诺如病毒（3.74%）和副溶血性弧菌（3.27%）为主。结论 需面向家庭、学校和学生开展有针对性的食品安全知识宣传,加强中小学生食源性疾病的重点食品和场所的食品安全监测和监管,最大限度地减少中小学生食源性疾病的发生。     

益糖康通过抑制AGE/RAGE信号通路改善骨骼肌细胞凋亡的机制

目的：研究益糖康通过抑制糖基化终末产物(AGE)/糖基化终末产物受体(RAGE)信号通路纠正骨骼肌细胞过度凋亡进而改善胰岛素抵抗(IR)的作用机制。方法：(1)体外实验,制备益糖康含药血清,将C2C12细胞设置空白组、模型组、益糖康含药血清高、中、低剂量(40、20、10 g·kg^-1)组、RAGE抑制剂组,除空白组外,用棕榈酸诱导C2C12 IR模型细胞,然后分别采取相应的干预方式后检测各组细胞的活性及葡萄糖消耗量水平,用流式细胞术检测各组细胞凋亡率,实时荧光定量聚合酶链式反应(Real-time PCR)及蛋白免疫印迹法(Western blot)检测重要凋亡蛋白[B细胞淋巴瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、p53、胱天蛋白酶(Caspase)-3、Caspase-9]的mRNA及蛋白表达水平。(2)体内实验,将96只符合研究标准的Wistar大鼠设置空白组、对照组、益糖康高、中、低剂量组(40、20、10 g·kg^-1)、吡格列酮(1.35 mg·kg^-1)组,运用高糖高脂糖尿病模型诱导饲料联合...     

基于GSK-3β/CREB信号通路探讨加味肾气丸减轻糖尿病小鼠肾间质纤维化的作用机制

目的 观察加味肾气丸对糖尿病肾病小鼠肾功能及纤维化的影响,并基于糖原合成酶激酶-3β（GSK-3β）/环磷腺苷效应原件（CREB）信号通路探讨其可能的作用机制。方法 雄性db/db小鼠50只,db/m小鼠10只。50只db/db小鼠按体质量随机分为模型组、厄贝沙坦组、加味肾气丸低、中、高剂量组。db/m小鼠10只为正常组。加味肾气丸低、中、高剂量组中药颗粒剂混悬液灌胃,厄贝沙坦组给予厄贝沙坦混悬液灌胃,正常组及模型组予等体积蒸馏水灌胃,连续干预12周。分别记录治疗前后小鼠的血糖和尿白蛋白肌酐比（UACR）及小鼠肾脏中GSK-3β、CREB、转化生长因子-β₁（TGF-β₁）、钙黏蛋白E（E-cadherin）、波形蛋白（Vimentin）、纤维粘连蛋白（FN）、纤溶酶原激活物抑制剂-1（PAI-1）、Ⅳ型胶原蛋白（Col Ⅳ）蛋白的表达水平,并观测小鼠肾脏的病理损伤程度。结果 与正常组比较,模型组小鼠血糖、UACR水平及肾脏中GSK-3β、TGF-β₁、E-cadherin、Vimentin、FN、PAI-1、Col Ⅳ蛋白的表达水平明显升高（P<0.05）,CREB蛋白表达水平明显下降（P<0.05）,小鼠肾脏病理损伤严重;与模型组比较,肾气丸低、中、高剂量组和厄贝沙坦组小鼠血糖、UACR水平及肾脏中GSK-3β、TGF-β₁、E-cadherin、Vimentin、FN、PAI-1、Col Ⅳ蛋白的表达水平均有不同程度下降（P<0.05）,CREB蛋白表达水平升高（P<0.05）,小鼠肾脏病理损伤有不同程度的减轻。结论 肾气丸可有效降低血糖、改善肾功能和纤维化,其作用机制与其抑制GSK-3β/CREB信号通路有关。     

磁共振成像对前置胎盘的临床诊断价值

目的：探究磁共振成像（MRI）对前置胎盘的诊断价值。方法：选取2018年1月至2021年6月新疆生产建设兵团医院接诊的基于临床症状诊断为前置胎盘孕妇79例,所有孕妇均在手术前行盆腔MRI扫描,观察胎盘厚度、宫颈长度、胎盘T2低信号带、宫颈边缘窦、膀胱隆起、子宫肌层变薄信号,分析上述MRI征象、指标对前置胎盘的诊断价值。结果：79例孕妇中,最终经手术病理证实为前置胎盘的患者52例。MRI征象中的胎盘T2低信号带、宫颈边缘窦、膀胱隆起、子宫肌层变薄均可有效诊断前置胎盘（P <0.05）;检出率由高到低依次为：胎盘T2低信号带>宫颈边缘窦>子宫肌层变薄>膀胱隆起;胎盘厚度≥10 mm时,胎盘厚度与前置胎盘呈正相关（r=0.852,P=0.016）;胎盘厚度<10 mm时,胎盘厚度与前置胎盘无相关性（r=0.201,P=0.052）。宫颈长度≥30 mm时,宫颈长度与前置胎盘无相关性（r=0.376,P=0.071）;宫颈长度<30 mm时,宫颈长度与前置胎盘呈负相关（r=–0.721,P=0.036）。结论：MRI征象（胎盘T2低信号带、宫颈边缘窦、膀胱隆...     

COVID-19对学术交流的影响及学术出版机构的应对举措

【目的】 研究COVID-19疫情暴发给学术交流及学术出版带来的深远影响。【方法】 利用文献调研法和案例分析法挖掘COVID-19疫情带来的学术环境变化,并探讨学术出版的整体变化趋势和国内外出版机构的应对方式。【结果】 COVID-19疫情改变了当前的学术交流环境:加速推进开放科学进程,快速传播的预出版模式受到青睐,开放评审促进快速学术交流,多项基金项目助力COVID-19科学研究,中国科研人员应对COVID-19反应积极而迅速。出版机构顺应学术出版的整体趋势,为科学共同体提供大量免费服务,扩大知识服务的目标群体,提供海量知识及COVID-19快速发表通道,我国出版机构应对COVID-19也采取了大量积极举措。【结论】 国内外出版机构应对突发事件时应建立学术出版应急机制,增强知识服务能力,促进知识创新及传播,以适应一个全新的快速发展的学术环境。