Specific immunoglobulin g antibody detected in umbilical blood and amniotic fluid from a pregnant woman infected by the coronavirus associated with severe acute respiratory syndrome

Specific immunoglobulin G antibody for severe acute respiratory syndrome (SARS) coronavirus was detected in maternal blood, umbilical blood, and amniotic fluid from a pregnant SARS patient. Potential protection of fetus from infection was suggested.     

Calcium homeostasis and glucose uptake of murine myotubes exposed to insulin,caffeine and 4‐chloro‐m‐cresol

The modulation of glucose uptake by cytosolic calcium and the role of insulin on calcium homeostasis in insulin‐target cells are incompletely understood and results are contradictory. To address this issue, we used the C2C12 murine skeletal muscle cell line model and examined the influence of caffeine and 4‐chloro‐m‐cresol, two ryanodine receptor agonists known to mobilize intracellular calcium stores and increase cytosolic free calcium concentration. We followed ⁴⁵calcium efflux, a validated indicator of cytosolic calcium concentration, and 3‐O‐methyl‐[1–³H]‐d ‐glucose uptake in parallel. We also determined if insulin incubation affected ⁴⁵calcium influx rate. A 30‐min treatment by 1 μm insulin highly significantly increased ⁴⁵calcium efflux by 8.5% (P = 0.0014), despite a significant reduction of ⁴⁵Ca²⁺ influx already measurable after 20 and 30 min of insulin stimulation (?16.6%, P = 0.0119 and ?21.3%, P = 0.0047, respectively). Caffeine (1–20 mm ) and 4‐chloro‐m‐cresol (0.05–10 mm ) concentration‐dependently increased ⁴⁵calcium efflux, the latter being more potent and efficacious. These agents, in a concentration‐dependent manner, inhibited both basal and, more potently, insulin‐stimulated glucose uptake. This resulted in a negative correlation of glucose uptake and ⁴⁵calcium efflux (r > 0.95, P < 0.001). This effect was ～5 times greater for caffeine than for 4‐chloro‐m‐cresol, suggesting a calcium‐independent part of the glucose uptake inhibition by caffeine. In our in vitro model of cultured muscle cells, insulin appears to prevent calcium overload by both stimulating efflux and inhibiting cell storage. This effect, taken together with the observed inhibitory, inverse relationship between ⁴⁵calcium efflux and glucose uptake, contributes to describing the complex insulin–calcium interplay involved in target cells.     

Effect of Carbohydrate Source on Kanagawa-Type Hemolysis of Vibrio parahaemolyticus

Almost all strains of Vibrio parahaemolyticus produced Kanagawa-type hemolysis on media of high salt content in the presence of fermentable carbohydrates.     

A polymorphic major histocompatibility complex class II‐like locus maps outside of both the chicken B‐system and Rfp‐Y‐system

Chickens have two major regions encoding major histocompatibility complex (MHC) class Iα genes and MHC class IIß genes, the serological and functional B‐system and the Rfp‐Y‐system. Recently, they have been shown to assort in a genetically independent way although still located on the same microchromosome. Moreover, the monomorphic MHC class IIα gene maps at a third locus located 5 c m from the nearest class IIß genes, located in the B‐system ( Kaufman et al., 1995 ). A pedigree family was studied in three generations in order to assign MHC class IIß restriction fragments observed in Southern blot analyses to either the B‐system, the Rfp‐Y‐system or the B‐Lα locus. In this study, we demonstrate by classical genetic testing of chickens within this fully pedigreed family the existence of an MHC class II‐like polymorphic restriction fragment that segregates independently of the B‐system, the Rfp‐Y‐system and of the B‐Lα locus.     

小檗胺诱导K562细胞凋亡及其与bcr/ablgene及P210表达的关系

目的:探讨小檗胺(BER)诱导K562细胞凋亡及其可能的机制。方法:以流式细胞仪(FCM)分析、电镜观察细胞微结构变化及基因组DNA电泳等方法检测细胞凋亡。以RT-PCR及Westernblot方法检测K562细胞BCR/ABLmRNA和蛋白质水平表达。结果:FCM检测见到典型的凋亡峰,8.0mg/LBER作用24-72h,随药物作用时间延长,细胞凋亡率由(29.20±3.82)%上升至(61.77±4.35)%(P＜0.01);以2.0-8.0mg/LBER作用24h,随药物浓度增加,K562细胞的凋亡率也增加。电镜下可见明确的细胞凋亡的形态学改变。DNA电泳呈现典型的梯形条带。16.0mg/LBER处理24h,K562细胞bcr/ablmRNA相对表达量及BCR/ABL融合蛋白质P210水平均明显低于对照组,分别为0.73±0.02vs1.19±0.02(P＜0.01)和0.63±0.01vs1.04±0.02(P＜0.01),呈时间-浓度依赖效应。经BER作用后,K562细胞bcr/ablmRNA表达强度与P210水平呈正相关(r=0.928,P＜0.05),且细胞凋亡率与bcr/ablmRNA表达呈负相关(r=-0.997,P＜0.01)。结论:在体外BER对K562细胞有明显的促凋亡作用,抑制bcr/ablmRNA表达及其蛋白质水平可能是其作用的重要机制之一。     

大鼠腘窝淋巴结内淋巴滤泡的生后发育

目的:研究大鼠淋巴结淋巴滤泡的生后发育.方法:采用常规组织学、免疫细胞化学及三维重建技术研究了大鼠腘窝淋巴结内淋巴滤泡的发生.结果:生后18天始,淋巴结浅层皮质内sIgM阳性B淋巴细胞聚集形成初级淋巴滤泡.生后3周ED-5阳性滤泡树突状细胞出现.随着鼠龄及体重的增长,初级淋巴滤泡不断扩大,每个淋巴结内淋巴滤泡数亦增多.生后13周滤泡数达高峰,平均每个淋巴结86个,13周以后体重缓慢增长,淋巴滤泡数逐渐下降.生后8周时,次级淋巴滤泡出现,ED-5阳性滤泡树突状细胞主要分布于亮区.结论:初级淋巴滤泡形成过程中B淋巴细胞聚集可能诱导局部网状细胞分化成滤泡树突状细胞;发育期间淋巴滤泡数随体重增长而增加可能与某些决定机体生长的因素作用有关.     

大鼠脊髓缺血再灌注损伤后caspase-12表达与细胞凋亡

目的:观察大鼠脊髓缺血再灌注损伤过程中细胞凋亡、caspase-12的表达变化规律,以探讨其分子机制。方法:采用自制压迫装置制备脊髓压迫缺血再灌注模型。运用形态学、分子生物学等方法,分别于缺血再灌注后3、7、11、23和47h,观察脊髓缺血再灌注损伤后,脊髓的病理变化和内质网的形态学改变、细胞凋亡及caspase-12的表达变化的规律。结果:脊髓缺血再灌注3h后,出现不同程度的细胞肿胀,神经元退行性变及内质网结构变化;随着再灌注时间的延长,神经元和神经胶质细胞凋亡数明显增加,并伴有caspase-12的表达增强;capspase-12表达与细胞凋亡的时空变化规律相一致。结论:在脊髓缺血再灌注过程中神经细胞凋亡是引起脊髓继发性损伤的主要病理因素,caspase-12可能参与了脊髓缺血再灌注损伤所导致的细胞凋亡。     

大鼠隔－斜带复合体中含小白蛋白蛋白和含胆碱乙酰化酶的神经元

用免疫细胞化学ＰＡＰ法，对成年大白鼠隔－斜带（Ｓ－ＤＢ）复合体中，含小白蛋白（ＰＶ）神经元的分布和形态学进行了研究，并与含胆碱乙酚化酶（ＣｈＡＴ）神经元的观察进行了比较。含ＰＶ神经元主要位于内侧隔核（ＭＳ）、斜带垂直支（ｖＤＢ）和斜带水平支（ｈＤＢ）。ＰＶ免疫反应神经元的形状和大小在Ｓ－ＤＢ复合体的各个核区或同一核区都不相同，表明这些神经元具有多样的形态学特征。在整个Ｓ－ＤＢ复合体中，含ＰＶ和含ＣｈＡＴ神经元的比例，各占ＰＶ和ＣｈＡＴ阳性反应细胞总数的４７／和５３／，在ＭＳ、ｖＤＢ和ｈＤＢ中，ＰＶ免疫反应神经元的比例分别为３８％、５４％和５９．５％，其余为含ＣｈＡＴ的胆碱能神经元。     

不同分子量尿毒血清组分对人肾小管上皮细胞CTGF基因和蛋白表达的影响

目的：探讨不同分子量尿毒血清组分对人肾小管上皮细胞结缔组织生长因子（CTGF）基因和蛋白表达的影响。方法:无菌条件下收集40份尿毒症病人血清和20例正常人血清，应用Centricon Plus 20 Centrifugal Filter Devices将尿毒血清分离成分子量 >10 000 D，5 000-10 000 D，<5 000 D 3个组分。应用Western blotting方法检测CTGF的蛋白表达，RT-PCR方法检测CTGF mRNA表达。结果:2.5%-20%浓度尿毒血清组CTGF基因表达均明显高于正常对照组，以10%尿毒血清组最高；分子量 <5 000 D尿毒血清组CTGF基因表达与正常对照组差异无显著，而分子量 5 000-10 000 D和 >10 000 D尿毒血清组CTGF基因表达均高于正常对照组，以分子量 >10 000 D尿毒血清组最高。不同浓度尿毒血清组CTGF蛋白表达均高于正常对照组，且有随着尿毒血清浓度的升高而增高，在不同分子量尿毒血清组中，以分子量 >10 000 D组增高最为显著。结论：尿毒症毒素通过影响人肾小管上皮细胞致纤维化细胞因子CTGF基因和蛋白表达从而在人肾小管-间质纤维化中起重要作用，而以分子量大于 10 000 D的尿毒症毒素在其中起主要作用。