饥饿大鼠胰岛胰高血糖素和嗜铬颗粒素A变化的定量免疫组织化学研究

用免疫组织化学ＡＢＣ法结合图像分析技术，研究饥饿状态下大鼠胰岛胰高血糖素（ｇｌｕｃａｇｏｎ，Ｇｌｕ）和嗜铬颗粒素Ａ（ｃｈｒｏｍｏｇｒａｎｉｎＡ，ＣｇＡ）的含量变化。结果表明，与正常对照组相比，饥饿大鼠胰岛Ａ细胞中Ｇｌｕ含量明显下降，ＣｇＡ含量仅在饥饿５ｄ后显著下降。这提示饥饿可导致Ｇｌｕ释放快速增加，而ＣｇＡ释放增加却较为缓慢。与饥饿５ｄ大鼠组相比较，饥饿５ｄ后静脉注射葡萄糖（１ｇ／ｋｇ体重）９０ｍｉｎ后胰岛Ａ细胞内Ｇｌｕ含量明显升高，ＣｇＡ含量无显著变化。提示静脉注射葡萄糖可作用于胰岛Ａ细胞，使Ｇｌｕ释放快速减少，但对ＣｇＡ的释放无影响。以上结果表明，外源性葡萄糖对胰岛Ａ细胞中Ｇｌｕ和ＣｇＡ两种物质的作用机制不同，为进一步阐明胰岛内Ｇｌｕ和ＣｇＡ的不同生理作用提供了形态学依据。     

马桑内酯致痫大鼠海马内c－fos原癌基因表达及谷氨酸免疫反应的变化

用免疫细胞化学双重染色法对马桑内酯致痫大鼠齿状回及海马回ＣＡ３区内原癌基因表达、谷氨酸免疫反应的变化及其相互关系进行了研究。一侧侧脑室内注射马桑内酯诱发癫痫后，在双重免疫细胞化学染色的切片上，齿状回及海马回ＣＡ３区内均有３种不同类型的细胞：谷氨酸（Ｇｌｕ）单标细胞、Ｆｏｓ单标细胞和Ｆｏｓ／Ｇｌｕ双标细胞。癫痫发作后１ｈ，注射侧齿状回有大量Ｆｏｓ／Ｇｌｕ双标细胞，而海马回ＣＡ３区仅有散在的双标细胞；癫痫发作后１．５ｈ，海马回ＣＡ３区双标细胞数明显增多。Ｆｏｓ单标细胞数及谷氨酸免疫反应性与双标细胞数是平行的。根据以上结果，本文对马桑内酯致痫的机制进行了讨论。     

"缺血"对大鼠大脑皮层神经元NMDA受体通道的影响

目的：研究“缺血”大鼠大脑大皮层神经元Ｎ－甲基－Ｄ－天冬氨酸（ＮＭＤＡ）受体通道的单通道变化特征。方法：细胞贴附式膜片钳技术。结果：在“缺血”状态下，ＮＭＤＡ受体通道３５ｐＳ和１００ｐＳ电导水平的开放概率分别由对照组的０．０７９±０．００６和０．０６７±０．００４增加到０．３０８±０．１５５和０．４８８±０．１２６（Ｐ＜０．０１），３５ｐＳ通道开放时间常数τ２由对照值（４．１７±０．３８）ｍｓ增加到（８．５４±２．０５）ｍｓ（Ｐ＜０．０１），关闭时间由（７５．５０±１４．１０）ｍｓ缩短到（１１．８０±４．３０）ｍｓ（Ｐ＜０．０１）。结论：“缺血”可显著开放大鼠大脑皮层神经元ＮＭＤＡ受体通道，使钙内流增加，对胞内钙超载起重要作用，此可能是脑缺血细胞损伤的机制之一。     

大鼠海马内谷氨酸神经元与GABA神经元之间突触联系的免疫电镜双标研究

为了探讨神经递质在癫痫发病机理中的作用，用包埋前免疫电镜双标法研究了正常太鼠海马ＣＡ１区谷氨酸（Ｇｌｕ）神经元与ＧＡＢＡ神经元之间的突触联系，先用ＤＡＢ为呈色剂显示ＧＡ－ＢＡ免疫反应，然后以钼酸铵－ＴＭＢ法显示Ｇｌｕ免疫反应，再进行免疫电镜包埋。观察发现，在海马ＣＡ１区锥体细胞层有许多Ｇｌｕ免疫反应性神经元；在锥体细胞层，多形层和辐状层可见一些ＧＡＢＡ免疫反应性神经元，胞体为锥体或多角形。在多形层     

大鼠第三脑室室管膜内谷氨酸免疫阳性结构的研究

为探讨一般室管膜在脑－脑脊液之间信息传递的作用，用ＰＡＰ免疫组织化学方法观察了成年大鼠下丘脑第三脑室室管膜内谷氨酸（Ｇｌｕ）免疫反应结构。首次在大鼠下丘脑第三脑室室管膜内观察到两种不同类型的Ｇｌｕ免疫反应结构：（１）Ｇｌｕ免疫反应性室管膜细胞，胞体呈椭圆形，常聚集成群；（２）Ｇｌｕ免疫反应神经细胞，胞体呈圆形或椭圆形，散在分布于室管膜细胞间，突起明显可见，多平行于室管膜表面行走。此外，在室管膜细胞间尚可见到Ｇｌｕ免疫反应神经纤维及膨体。其中部分纤维伸向室管膜表面。以上结果表明，部分室管膜细胞具有合成或摄取Ｇｌｕ的能力，而室管膜内的Ｇｌｕ能神经元可能是位于室管膜内的触液神经元。推测这些室管膜内的Ｇｌｕ免疫反应结构与脑－脑脊液之间的信息传递有关。     

脑缺血海马CA1区5-HT变化的免疫组织化学研究

目的：观察脑缺血及缺血再灌流海马ＣＡ１区５－ＨＴ的变化，探讨脑缺血海马ＣＡ１区神经元损伤与５－ＨＴ变化的关系。方法：用免疫组织化学ＡＢＣ法及图像分析技术对沙土鼠脑缺血海马ＣＡ１区５－ＨＴ含量变化进行研究。结果：（１）脑缺血１０ｍｉｎ时，沙土鼠海马ＣＡ１区５－ＨＴ免疫反应阳必纤维的平均光密度值（ＯＤ）与对照组比较无显著性差异。而缺血３０ｍｉｎ时，ＯＤ值则下降，４ｈ时下降得更多，Ｐ〈０．０５。（２）脑     

缺血性脑损伤海马神经元磷酸肌醇系统的变化及其机制的探讨

采用四动脉闭塞全脑缺血模型，观察大鼠缺血３０ｍｉｎ再灌注２１ｄ不同时间中，外源性谷氨酸对海马脑片磷脂酰肌醇代谢的影响和偶联该系统的Ｇ蛋白功能变化。。结果显示，Ｇｌｕ对正常和缺血再灌注海马脑片肌醇磷酸生成均具有明显的促进作用，其中以缺血再灌注后ＩＰ的升高为显著。     

饥饿大鼠胰岛胰高血糖素和嗜铬颗粒素A变化的定量免疫组织…

用免疫组织化学ＡＢＣ法结合图像分析技术，研究饥饿状态下大鼠胰岛血糖素和嗜铬颗粒素Ａ的含量变化。结果表明，与正常对照组相比，饥饿大鼠胰岛Ａ细胞中Ｇｌｕ含量明显下降，ＣｇＡ含量仅在饥饿５ｄ后显著下降。这提示饥饿可导致Ｇｌｕ释放快速增加，而ＣｇＡ释放增加却较为缓慢，与饥饿５ｄ大鼠组相比较，饥饿５ｄ后静脉注射葡萄糖９０ｍｉｎ后胰岛Ａ细胞，使Ｇｌｕ释放快速减少，但对ＣｇＡ的释放无影响。以上结果表明，我源性葡     

小檗碱对大鼠全脑缺血后海马的保护作用

本研究室以往曾发现小檗碱具有预防脑缺血短期（７ｄ）再灌流海马ＣＡ１迟发性神经元坏死（ＤＮＤ）的作用。本研究采用Ｐｕｌｓｉｎｅｌｌｉ－Ｂｒｉｅｒｌｅｙ四血管阻塞（４ＶＯ）致大鼠全脑缺血模型，观察了小檗碱对脑缺血（２ｍｉｎ）长期再灌流后海马的影响，并对脑缺血经短、长期再灌流对照及用药组大鼠进行了Ｍｏｒｒｉｓ水迷宫学习记忆能力检测。结果显示，小檗碱能有效的保护海马ＣＡ１区锥体细胞免于脑缺血后ＤＮＤ，经长期（３个月）再灌流后这种保护作用依然存在，细胞密度为１６８个／ｍｍ，占正常８０．５％；对脑缺血经长期再灌流引起的海马ＣＡ２、ＣＡ３、ＣＡ４继发性神经无死亡也有明显的对抗作用。脑缺血短期（１０ｄ）再灌流后，大鼠表现为明显的学习障碍，潜伏期延长，但经多次训练后，大鼠在原平台象限泳距比其它非平台象限都显著长，表明尚有良好的空间记忆能力；脑缺血经长期再灌流后，其空间学习障碍加重、记忆能力也受到严重影响。而用药组缺血大鼠无论短期或长期再灌流后，均保存了良好的空间学习、记忆能力。表明脑缺血经长期再灌流后，海马的形态和学习、记忆能力比短期再灌时将进一步受损害，而小檗碱不但对短期再灌流有保护作用，对长期再灌流的进一步损害也有明显的?     

脑缺血／再灌注后大鼠海马GABA、AchE水平和迟发性神经元损害关系的研究

为探讨海马ＧＡＢＡ、ＡｃｈＥ和迟发性神经元损害（ｄｅｌａｙｅｄｎｅｕｒｏｎａｌｄａｍａｇｅ，ＤＮＤ）的关系，观察了脑缺血／再灌注后大鼠海马亚区ＧＡＢＡ含量、ＡｃｈＥ活性和海马组织病理改变。发现再灌注５ｍｉｎ，海马亚区ＧＡＢＡ含量显著升高，再灌注１ｈ和６～１２ｈ，ＧＡＢＡ含量明显降低，ＣＡ＿１区更明显。再灌注５ｍｉｎ至１ｈ，海马亚区ＡｃｈＥ活性明显升高。再灌注４８ｈ后，光镜下见海马ＣＡ＿１区神经元出现缺血性改变，提示：（１）再灌注后，ＧＡＢＡ含量减少、海马内源性抑制降低可能是ＣＡ＿１区ＤＮＤ的因素之一。（２）再灌注早期ＡｃｈＥ活性升高，提示Ａｃｈ代谢变化可能和ＤＮＤ有关。（３）再灌注后ＧＡＢＡ和ＡｃｈＥ在海马各亚区的明显改变，提示ＣＡ＿１区选择性易损和递质代谢变化密切相关，而ＣＡ＿１区神经元本身的生理生化特性也起着重要的作用。     

Development in in vitro toxicology

There are three principal pressures driving the development of in vitro toxicology: (1) the need for more efficient testing systems to cope with the large number of xenobiotics currently being developed; (2) public pressure to reduce animal experimentation; and (3) a need for a better understanding of the mechanisms of toxicity. Within this, in vitro toxicology is focused on local, systemic, and target-organ toxicity. It is becoming increasingly apparent that a step or decision-tree approach using input of a variety of experimental data (physicochemical properties, biokinetics, cytotoxicity) provides the most efficient system for predicting toxicity. Examples of the use of in vitro toxicity systems for prediction of systemic toxicity and target-organ (liver) toxicity are presented.Originally presented at ECCP 93.     

Seasonal variations in acute toxoplasmosis in pregnant women in Slovenia

Between December 1999 and December 2004, 40 081 pregnant women were examined for toxoplasmosis with Toxo-IgG, Toxo-IgM enzyme immunoassay. Women with positive results were then retested with the Toxo-IgG avidity assay for recent toxoplasmosis. Recent acute toxoplasmosis in pregnant women was found to be significantly more frequent (p < 0.01) during winter than summer. The incidence of acute toxoplasmosis during winter-spring was also significantly more frequent (p < 0.025) than summer-autumn. This phenomenon should be taken into account when formulating preventive measures for toxoplasmosis, especially for pregnant women.     

Age-related changes in polyamines in memory-associated brain structures in rats

Polyamines putrescine, spermidine and spermine are positively charged aliphatic amines and have important roles in maintaining normal cellular function, regulating neurotransmitter receptors and modulating learning and memory. Recent evidence suggests a role of putrescine in hippocampal neurogenesis, that is significantly impaired during aging. The present study measured the polyamine levels in memory-related brain structures in 24- (aged), 12- (middle-aged) and 4- (young) month-old rats using liquid chromatography/mass spectrometry and high performance liquid chromatography. In the hippocampus, the putrescine levels were significantly decreased in the CA1 and dentate gyrus, and increased in the CA2/3 with age. Significant age-related increases in the spermidine levels were found in the CA1 and CA2/3. There was no difference between groups in spermine in any sub-regions examined. In the parahippocampal region, increased putrescine level with age was observed in the entorhinal cortex, and age did not alter the spermidine levels. The spermine level was significantly decreased in the perirhinal cortex and increased in the postrhinal cortex with age. In the prefrontal cortex, there was age-related decrease in putrescine, and the spermidine and spermine levels were significantly increased with age. This study, for the first time, demonstrates age-related region-specific changes in polyamines in memory-associated structures, suggesting that polyamine system dysfunction may potentially contribute to aged-related impairments in hippocampal neurogenesis and learning and memory.     

休克过程中肾上腺髓质素变化的研究进展

Adrenomedullin (AM) is a new peptidergic regulator of vascular function. AM serves as a hormone, which has many biological properties, plays an important role in the many pathophysiological processes, especially shock. This review will highlight the structure, biological properties of AM and the relationship between AM and shock.     

Secular change in menarche in women in Madrid

The age at menarche was estimated by recollection in 1617 women between the ages of 18 and 60 in Madrid and a nearby suburb, Pinto. The population of Pinto is working-class and the Madrid group, taken from residential neighbourhoods , belongs to the upper middle class. In both groups we found a diminution in average age at menarche, from 14.04 to 13.02 years in Madrid and from 14.55 to 13.16 years from about 1935 to about 1965 in Pinto. These changes have been more intense in the group which is less well-off economically, where living conditions have varied much more drastically.     

Pitfalls in TRAP assay in routine detection of malignancy in effusions

Telomerase has been found to be reactivated in a majority of cancers but is inactive in most somatic cells. Our principal goal was to determine the potential use of the telomeric repeat amplification protocol (TRAP) assay as marker for malignancy in cytological effusions. The simple selection criterion was the cytological diagnosis, and routine samples were classified into malignant (58 samples) and nonmalignant (233 samples). Of the malignant samples, 44/58 (76%) were positive by TRAP assay. Of the 14 telomerase-negative cytology-positive samples, RNA integrity was poor in 9, indicating suboptimal sample conservation for molecular analysis. In 3 of the remaining 5 samples with a negative TRAP assay, a high number of malignant cells was observed, and these cells might have been telomerase-negative. Thus, the sensitivity of TRAP assay for the presence of malignant cells was about 76%. In the cytologically nonmalignant effusions, the presence of telomerase activity was observed in 24% (55/233). Of these, 6% were highly suspicious for malignancy, 9% were doubtful, and 9% were cytologically nonmalignant effusions confirmed by a follow-up of 12 mo or more. According to these data, the specificity of the TRAP assay to detect tumor cells in effusions ranged only between 82-91%. Our results indicate that, although the TRAP assay is positive in 6-15% of putative malignant effusions, the relatively high number of TRAP false-negative and false-positive cases renders this test unsuitable for routine diagnostic purposes.