Retinoic acid receptor beta variant‐related colonic hypoganglionosis

Retinoic acid receptor beta (RARB) variants are heavily linked to pathologies of neural crest cell migration. The purpose of this report is to present a 23‐month‐old male with the previously described R387C RARB gain‐of‐function variant whose gastrointestinal issues and long‐term constipation lead to the discovery of colonic hypoganglionosis. This case further delineates the pattern of malformation associated with RARB variants. The findings are also consistent with the known etiology of aganglionic colon due to failed neural crest cell migration.     

川芎嗪对内毒素脂多糖诱导的体外血脑屏障模型通透性增高的保护作用及其机制

目的:探讨川芎嗪对内毒素脂多糖(LPS)诱导的体外血脑屏障模型通透性增高的保护作用及其调控机制。方法:利用脑微血管内皮细胞与星型胶质细胞共培养建立体外大鼠血脑屏障模型,随机分为正常对照组、川芎嗪对照组、LPS干预组和川芎嗪治疗组。采用γ计数仪检测~(125)I-BSA通透量观察体外血脑屏障模型通透性的改变,Western印迹法检测紧密连接蛋白(zonula occludens-1,ZO-1)表达量的变化。结果:LPS使体外血脑屏障模型对~(125)I-BSA的通透量明显增加,脑微血管内皮细胞ZO-1蛋白表达下降,川芎嗪治疗组能明显拮抗LPS的上述作用。结论:川芎嗪对LPS诱导的体外血脑屏障通透性增高具有保护作用,其机制与它能影响血脑屏障紧密连接蛋白ZO-1表达有关。     

Selenium improves cardiac function by attenuating the activation of NF-kappaB due to ischemia-reperfusion injury

Although selenium, an essential trace element and a component of glutathione peroxidase, is known to protect the heart from ischemia-reperfusion (I/R)-induced injury, the mechanisms of this protection are not fully understood. For this purpose, isolated rat hearts were subjected to 30 min of global ischemia followed by 30 min of reperfusion; sodium selenite (25-1,000 nM) was added in the perfusion medium 10 min prior to ischemia, as well as during reperfusion. Selenium caused a dose-dependent improvement in cardiac performance and attenuated the decrease in the ratio of reduced glutathione to oxidized glutathione, as well as the increased level of malondialdehyde in I/R heart. Elevated ratios of nuclear factor-kappaB (NF-kappaB) in particulate and cytosolic fraction and of phosphorylated NF-kappaB and total NF-kappaB in I/R hearts were reduced by selenium. Cardiac dysfunction in hearts perfused with xanthine plus xanthine oxidase mixture, as well as hydrogen peroxide, or subjected to Ca2+ paradox was also attenuated by selenium. These data suggest that selenium protects the heart against I/R injury due to its action on the redox state and deactivation of NF-kappaB in I/R hearts.     

蝎蜂毒肽对大鼠纤溶系统作用初探

本研究采用大鼠肢体血管灌流和整体给药两种模型，观察蝎蜂毒（ＳＢＰ）对血管理灌流液内纤溶酶原激活物（ＰＡ）活性、血浆优球蛋白纤溶性（ＥＦＡ）和纤溶酶（ＰＬ）活性的影响。结果说明，ＳＢＰ有明显激活纤溶系统作用；其机制可能涉及血管内皮细胞释放ＰＡ活性增加，进一步促使纤溶酶原活化为ＰＬ增多的途径。     

莱姆病螺旋体60kD抗原的基因克隆及表达

利用质粒ｐＡＴ１５３为载体，构建了莱姆螺旋体全细胞ＤＮＡ基因文库，用菌落原位固相酶斑法从文库中初选出一株表达６０ｋＤ抗原的克隆子，命名为ｐＬＷ２２７。经免疫印迹分析、核酸杂交、连续亚克隆分析，证明此重组菌株表达了莱姆螺旋体６０ｋＤ抗原，编码该抗原的基因表达单位为２．２ｋｂ或更小，位于莱姆螺旋体的染色体上。该抗原的表达为进一步研究莱姆病的致病机理打下了基础。     

白细胞介素—1对大鼠下丘脑室旁核Fos癌蛋白和CRF的诱导作用

将白细胞介素-1(IL)注入大鼠侧脑室,用Fos癌蛋白抗体免疫组化法检测了下丘脑室旁核的激活神经元:大量位于含促肾上腺皮质激素释放因子(CRF)相应区域的室旁核小细胞部神经元呈Fos免疫强阳性。Fos和CRF的免疫双染色显示了许多Fos免疫阳性神经元也呈CRF免疫阳性。此外,在IL-1注射动物中,CRF的免疫阳性显著加强,提示CRF合成增加。     

交链孢酚激活人胎食管上皮组织细胞癌基因的研究

本文报道食管癌高发区粮食中优势污染菌互隔交链孢霉代谢产物交链孢酚(AOH)对人胎儿食管上皮组织癌基因的激活。结果表明,体外培养的人胎儿食管上皮组织经10gg/ml AOH作用4h后,其DNA具有转化活性,可转化NIH/3T3细胞。一轮转化率为0.17Foci/μg DNA,二轮转化率为0.58Foci/μg DNA(P<0.01)。转化细胞中含有人特异性高重复序列Alu,提示转化系人DNA转染所致。Southern blot检测表明,AOH处理后的人胎儿食管上皮组织内有H-ras和myc基因的扩增,经其转染的NIH/3T3细胞中亦有H-ras基因持久而稳定的扩增。对照组胎儿食管上皮和正常NIH/3T3细胞中均未发现相应的同源序列,说明正常胎儿食管组织中的H-ras和myc基因可经AOH短期处理而激活。该结果对AOH可能系人食管癌病因之一提供了直接证据。     

休克大鼠小肠微循环灌流量和血清TNF的变化及多巴胺的作用

在39只失血性休克大鼠中，用激光多普勒微循环血流计及ELISA法测定静脉注射多巴胺前后小肠微循环增流量及血清TNF浓度的变化。结果发现随休克发展，小肠微循环血液灌流量进行性减少，TNF浓度升高。多巴胺（40μg／100gB．W．）治疗可增加小肠微循环血液油流量和降低血清TNF浓度。两者间呈显著性相关（r＝0．897，P＜0．01）。作者认为，多巴胺通过增加小肠微循环血液灌流量，改善肠壁屏障功能，减少内毒素入血，从而降低血清TNF浓度，保护了脏器功能和减轻细胞损伤。