腹部开放伤合并人工海水浸泡大鼠肠道免疫屏障功能的变化

目的 探讨腹部开放伤合并人工海水浸泡大鼠肠道免疫屏障功能的变化及意义.方法 建立腹部开放伤合并人工海水浸泡大鼠致伤模型.50只Wistar大鼠随机分为5组,每组10只.A组:腹部开放伤合并海水浸泡组;B组:单纯腹部开放伤组;C组:单纯海水浸泡组;D组:腹部开放伤合并生理盐水浸泡组;E组:正常对照组.观察腹腔海水浸泡后肠内容物sIsA及血浆IgA、内毒素(LPS)、肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)含量变化及血、肝脏、肠系膜淋巴结细菌定量培养情况;观察HE染色小肠组织病理损伤评分.结果 与E组比较,A组肠内容物SIgA、血浆IgA含量显著下降;血浆LPS、TNF-α、IL-6含量显著升高;发生肠道细菌易位(P＜0.05或P＜0.01);HE染色显示小肠黏膜组织出现不同程度的损伤(P＜0.05或P＜0.01).结论 腹部开放伤合并海水浸泡后肠道免疫屏障功能显著下降,与内毒素血症和肠道细菌易位的发生密切相关,炎症因子释放及肠黏膜屏障功能损伤是肠道免疫屏障功能受损的重要机制之一.     

The complexity of neurobiological processes in acute ischemic stroke

There is an urgent need for improved diagnostics and therapeutics for acute ischemic stroke. This is the focus of numerous research projects involving in vitro studies, animal models and clinical trials, all of which are based on current knowledge of disease mechanisms underlying acute focal cerebral ischemia. Insight in the chain of events occurring during acute ischemic injury is essential for understanding current and future diagnostic and therapeutic approaches.     

Estrogen–BDNF interactions: Implications for neurodegenerative diseases

Since its’ discovery over 20 years ago, BDNF has been shown to play a key role in neuronal survival, in promoting neuronal regeneration following injury, regulating transmitter systems and attenuating neural-immune responses. Estrogen’s actions in the young and mature brain, and its role in neurodegenerative diseases in many cases overlaps with those observed for BDNF. Reduced estrogen and BDNF are observed in patients with Parkinson’s disease and Alzheimer’s disease, while high estrogen levels are a risk factor for development of multiple sclerosis. Estrogen receptors, which transduce the actions of estrogen, colocalize to cells that express BDNF and its receptor trkB, and estrogen further regulates the expression of this neurotrophin system. This review describes the distribution of BDNF and trkB expressing cells in the forebrain, and the roles of estrogen and the BDNF–trkB neurotrophin system in Parkinson’s disease, Alzheimer’s disease and multiple sclerosis.     

十二指肠大乳头的扫描电镜形态特征

对3例成人十二肠大乳头进行扫描电镜观察，结果为大乳头口附近的粘膜皱襞呈纵横交错，并围成大小不等的窦腔，本从胚胎发生及临床应用进行了讨论。     

Increased collagen content of cerebral microvessels in Alzheimer's disease

Based on previous evidence suggesting abnormalities in the brain microvasculature, we examined basement membrane collagen in isolated cerebral microvessels (CMV) from subjects with Alzheimer's disease (AD) and age-matched controls. Concentrations of hydroxyproline, the principal constituent of collagen IV, were significantly increased by 55% in CMV from AD subjects compared to controls. This result was corroborated by the finding of 60% increased total collagen content in CMV as evident by the selective binding of Sirius red dye. Hydroxyproline and collagen concentrations in samples of cerebral cortex assayed in parallel were 6–20 times smaller than in CMV and were not changed between controls and AD subjects. To further differentiate AD and control samples, fractions of CMV were solubilized and the pepsin digested collagen proteins resolved by SDS-PAGE. Upon immunoblotting, AD samples with increased collagen revealed proportionally greater specific immunoreactivities detected by antibodies to collagen IV. Our observations suggest altered collagen IV content of cerebral vessels in subjects with AD that may affect brain microvascular functions.     

Growth factors in the aqueous humor and their therapeutic implications in glaucoma and anterior segment disorders of the human eye

The presence of growth-promoting substances in the aqueous humor has been suspected for the past decade, but it has been only during the last 2 years that the existence of growth factors such as basic fibroblast growth factor, epidermal growth factor, transforming growth factorp, transferrin, and insulin-like growth factors in the aqueous humor has been demonstrated. The structures that border the anterior and posterior chambers of the eye syn- thesize some of these growth factors and release them into the aqueous humor. A breakdown of the blood-aqueous-barrier increases the amounts of growth factors and may also bring platelet-derived growth factor, nerve growth factor, and interleukin-6 into the aqueous humor. Growth factors maintain the normal function of ocular tissues in health and have a significant role in the pathogenesis and possible management of several disorders of the eye. The outcome of the pathogenetic process and its modulation are determined by a complex coordination and interactions of the growth factors in the aqueous humor and their eventual effect on the target tissues. We discuss the therapeutic implications of growth factors and their antagonists in the treatment of certain disorders of the anterior segment of the eye, including rubeosis iridis, neovascular glaucoma, primary open-angle glaucoma, sand wound after filtration Surgery.     

灯盏细辛对脑缺血再灌注后血脑屏障通透性及脑代谢物质的影响

目的:探讨灯盏细辛治疗脑缺血损伤的作用机制.方法:大鼠100只.制作改良的脑缺血/再灌注模型.其中65只随机分为假手术组、模型组、灯盏细辛治疗组(10%灯盏细辛注射液22.5mg·kg~(-1)).假手术组(n=5)术后1 d处死取材,测定脑含水量、BBB通透性;治疗组和模型组在缺血1.5 h再灌后6,12 h,1,2,4,7 d处死取材,两组每时间点各取5只测定脑含水量、BBB通透性.另外35只大鼠随机分为假手术组、模型组和治疗组.假手术组造模后立即进行T_2加权像(T_2-weighted imaging,T_2WI)、脑代谢物质的检测,1 d时处死取材测定脑梗死比:治疗组和模型组在缺血1.5 h再灌后1,2,4 d进行T_2WI、脑代谢物质检测后处死取材,测定脑梗死比.结果:模型组再灌后6 h脑含水量(77.93±0.68)%增加,4 d脑含水量(83.82±0.49)%达到高峰;BBB通透性在2 d(5.51±0.24)mg·kg~(-1)达到高峰.治疗组4 d脑含水量(82.84±0.65)%比模型组同时间点下降:治疗组2 d BBB通透性(4.62±0.26)mg·kg~(-1)比模型组同时间点下降.活体检测模型组鼠脑T_2WI,再灌1 d后损伤区出现高信号强度区.脑代谢物质检测显示,治疗组比模型组同时间点N-乙酰天门冬氨酸(N-acetyl aspartate,NAA)与肌酐(Cr)比值减低,胆碱((;ho)与肌酐比值增大.2,3,5-三苯基氯化四氮唑(TTC)染色,治疗组比模型组同时间点梗死面积比小,2 d时治疗组脑梗死比为(16.78±1.45)%,而模型组为(21.27±1.73)%.结论:灯盏细辛能够减轻大鼠脑缺血再灌注损伤,其机制可能是通过调节脑缺血再灌注后的物质代谢,稳定BBB,减轻脑水肿.     

Quantitation and localization of blood-to-brain influx by magnetic resonance imaging and quantitative autoradiography in a model of transient focal ischemia.

The ability of gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) enhanced MRI to localize and quantitate blood-brain barrier (BBB) opening was evaluated against quantitative autoradiographic (QAR) imaging of (14)C-alpha-aminoisobutyric acid (AIB) distribution. The blood-to-brain transfer constant (K(i)) for Gd-DTPA was determined by MRI in rats after 3 h of focal cerebral ischemia plus 2.5 h of reperfusion (n = 9), and that of AIB was determined by QAR shortly thereafter. Tissue regions of interest (ROIs) for Gd-DTPA leakage were identified by ISODATA segmentation of pre- and post-Gd-DTPA Look-Locker (L-L) T(1) maps. Patlak plots were constructed using time course of blood and tissue T(1) changes induced by Gd for estimating K(i). Among the nine rats, 14 sizable regions of AIB uptake were found; 13 were also identified by ISODATA segmentation. Although the 13 MRI-ROIs spatially approximated those of AIB uptake, the segmentation sometimes missed small areas of lesser AIB uptake that did not extend through more than 60% of the 2.0-mm-thick slice. Mean K(i)'s of AIB were highly correlated with those of Gd-DTPA across the 13 regions; the group means (+/-SD) were similar for the two tracers (7.1 +/- 3.3 x 10(-3) and 6.8 +/- 3.5 x 10(-3) ml.g(-1) . min(-1), respectively). In most instances, Gd-DTPA MRI accurately localized areas of BBB opening.     

老龄大鼠脑缺血再灌注血脑屏障损伤的变化及意义

目的研究老龄大鼠脑缺血再灌注（I／R）血脑屏障（BBB）损伤特点。方法采用大脑中动脉栓塞法复制局灶性脑缺血模型，随机分组，观察脑组织含水量、病理变化、免疫球蛋白（IgG）。结果随着再灌注时间的延长，BBB损伤逐渐加重，含水量增加和IgG漏出以I／R24h、3d显著；模型组含水量（I／R 12h～6d）较假手术组升高；青年模型（I／R12h～6d）和老龄模型（I／R 6h～6d）IgG漏出分别较青年和老龄脑缺血3h组增加；老龄模型组（I／R 12h～I／R6d）IgG的漏出高于同时间青年模型组。结论脑水肿和BBB损伤随着再灌注时间的延长而加重，IgG漏出老年较青年明显，血脑屏障的增龄变化可能是其机制之一。