一氧化氮合酶抑制剂对大鼠结肠炎损伤的影响

目的：了解一氧化氮合酶抑制剂L－精氨酸甲酯（L-NAME）对大鼠结肠炎损伤的影响。方法：将实验大鼠随机分为对照组、损伤组、NAME1、NAME2、NAME3（即N1、N2、N3）干预组。采用三硝基苯磺酸（TNB）30 mg+50%乙醇0.25 mL给大鼠灌肠复制结肠炎模型，并检测各组的溃疡指数（UI）、一氧化氮（NO）、MDA含量及GSH活性。结果：N1、N2、N3组的NO、UI、MDA值低于损伤组，GHS值高于损伤组，对照组的损伤不明显。相关分析表明，NO含量与MDA含量呈正相关，与GSH活性呈负相关。结论：在结肠炎症反应中，NO过量生成具有损伤作用，L－NAME通过抑制NOS活性，减少NO及自由基的生成，具一定的抗损伤作用。     

硝普钠对大鼠应激性胃粘膜损伤的保护作用

采用浸水束缚应激法建立大鼠应激性胃溃疡模型，观察一氧化氮供体硝普钠对大鼠胃粘膜损伤的保护作用。结果表明，硝普钠可以明显减轻浸水应激引起的胃粘膜损伤，抑制胃运动亢进，同时增加胃粘膜血流量以及血浆和胃粘膜中NO和SOD含量，降低MDA和ET含量。提示硝普钠对浸水应激性胃粘膜损伤的保护作用可能是通过增加胃粘膜血流量和抑制胃运动亢进共同实现的。     

硝普钠对大鼠应激性胃粘膜损伤的保护作用

采用浸水束缚应激法建立大鼠应激性胃溃疡模型，观察一氧化氮供体硝普钠对大鼠胃粘膜损伤的保护作用。结果表明，硝普钠可以明显减轻浸水应激引起的胃粘膜损伤，抑制胃运动亢进，同时增加胃粘膜血流量以及血浆和胃粘膜中NO和SOD含量，降低MDA和ET含量。提示硝普钠对浸水应激性胃粘膜损伤的保护作用可能是通过增加胃粘膜血流量和抑制胃运动亢进共同实现的。     

血必净注射液对急性梗阻性黄疸大鼠心肌损伤的保护作用

目的：观察血必净注射液对急性梗阻性黄疸大鼠心肌损伤的保护作用。方法：采用结扎SD大鼠胆总管的方法制作急性梗阻性黄疽动物模型。将54只SD大鼠随机均分为胆总管结扎（BDL）组、胆总管结扎血必净治疗组（XBJ）、假手术组（SO）3组。XBJ组在胆总管结扎后48h开始尾静脉注射血必净注射液,BDL组和SO组同样方法注射等量生理盐水。分别于给药后第3、7、14天各取6只大鼠采样,观察血清胆红素（TBIL）、肌酸激酶同工酶（CK—MB）、内毒素（ET）含量,心肌组织丙二醛（MDA）和超氧化物歧化酶（SOD）含量,以及光镜下观察心肌病理变化。结果：急性胆道梗阻后,血清TBIL、CK—MB、ET水平及心肌组织MDA含量随梗阻时间延长逐渐增高,心肌组织SOD含量减少。XBJ组与同时相BDL组比较,血清TBIL、CK—MB、ET水平及心肌组织MDA含量减少,心肌组织SOD含量增高。光镜下可见随胆道梗阻时间延长,心肌损伤加重,XBJ组与同时相BDL组比较,心肌损伤减轻。结论：血必净注射液对急性胆道梗阻所致心肌损伤有保护作用,作用机制可能与其抗内毒素血症、TNF—α作用及对抗氧自由基有关。     

NG-硝基-L-精氨酸对大鼠内毒素性肺线粒体损伤的影响

目的： 观察非选择性一氧化氮合酶(NOS)抑制剂NG-硝基-L-精氨酸(L-NA)对急性肺损伤大鼠肺线粒体功能的影响，并探讨其改善急性肺损伤的作用机制。方法: 将SD大鼠随机分为空白对照组、急性肺损伤组、L-NA治疗组，采用舌静脉注射脂多糖(LPS)复制大鼠急性肺损伤模型，于大鼠急性肺损伤3h后给L-NA治疗3h，断头放血处死大鼠，迅速取出肺脏，匀浆器混匀后，低温差速离心法提取肺线粒体，测定线粒体总ATP酶、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）、总一氧化氮合酶（T-NOS）、诱生型一氧化氮合酶（iNOS）、结构型一氧化氮合酶（cNOS）的活性，以及线粒体肿胀度、膜流动性和线粒体一氧化氮（NO）、丙二醛（MDA）含量；电镜观察大鼠肺线粒体超微结构的改变及治疗药对此改变的影响。结果: 在大鼠内毒素性急性肺损伤后，肺脏组织中线粒体表现为肿胀、膜流动性降低，线粒体中的T-NOS和iNOS活性显著升高，线粒体NO生成明显增加，而cNOS活性无明显变化；线粒体总ATP酶、SOD、GSH-Px活性均明显下降，线粒体MDA含量明显升高。急性肺损伤3h给予L-NA治疗3h,与急性肺损伤组相比，一氧化氮合酶活性有所改变，NO生成显著下降，总ATP酶、SOD、GSH-Px活性均显著升高，MDA含量下降。电镜结果显示内毒素性急性肺损伤后肺脏组织细胞水肿，线粒体肿胀、嵴断裂、溶解、消失；L-NA能改善内毒素性急性肺损伤引起的细胞水肿、线粒体肿胀和空泡化。结论: L-NA能明显抑制急性肺损伤后线粒体一氧化氮合酶活性，减少NO生成，改善线粒体能量供应，增加线粒体抗氧化作用，从而减轻急性肺损伤。     

丹参提取物F对大鼠乙醇性胃粘膜损伤的影响及其机制的研究

在大鼠乙醇性胃粘膜损伤模型上，丹参提取物Ｆ ０．１ｍｌ／２００ｇ／ｍｉｎ ｉｖ５分钟可明显降低胃粘膜伊文斯兰含量（Ｐ＜０．０１）和被单星蓝染色的面积（Ｐ＜０．０１）及胃粘膜损伤程度（Ｐ＜０．０１）。用ＴＳ－２００组织光谱分析仪测定大鼠胃粘膜表层血液量和Ｈｂ氧饱和度，表明丹参提取物Ｆ可维持大鼠胃粘膜在６０％乙醇（容积比）后血液量和Ｈｂ氧饱和度基本不变。结果提示：丹参提取物Ｆ有抗大鼠乙醇性胃粘膜损伤作     

门脉高压时胃粘膜病变发生机制的实验研究

为探讨门脉高压时胃粘膜病变的发生机制，本文对四氯化碳所致的肝硬变伴门脉高压大鼠的胃粘膜主要防御和损伤因子进行了测定，并观察了胃粘膜超微结构。结果表明，门脉高压大鼠的胃粘膜前列腺素Ｆ２含量、胃粘膜血流量和胃壁结合粘膜量明显低于正常大鼠（均为Ｐ＜０．００１），而胃液ｐＨ值，胃酸浓度、胃酸分泌量和胃蛋白酶活性与正常比较无明显差异（均为Ｐ＞０．０５）。门脉高压大鼠的胃粘膜毛细血管组织结构的完整性破坏，毛细     

长时间应用L-精氨酸增强大鼠学习记忆功能和大脑皮质、海马nNOS或c-fos的表达及神经元数目的增加(英文)

为探讨长时间应用一氧化氮(NO)对学习记忆功能和神经系统可塑性的影响,以及NO与c-fos基因表达的关系,分别给初断乳的大鼠灌胃NO前体左旋-精氨酸(L-Arg)或一氧化氮合酶抑制剂L-NAME,用Morris水迷宫检测大鼠的学习记忆功能,用免疫组化技术和HE染色检测大脑皮质和海马CA1、CA3、DG区的神经元型一氧化氮合酶(nNOS)和c-fos基因的表达以及神经细胞数目的变化。将大鼠随机分成L-Arg组、L-NAME组和对照组。大鼠断乳后分别每天用L-Arg[200mg/(kg.d)]、L-NAME[50mg/(kg.d)]和等剂量的蒸馏水灌胃,持续3个月。结果显示:长期应用NO前体L-Arg可明显缩短大鼠的寻台潜伏期,促进nNOS和c-fos基因的表达,同时大脑皮质和海马CA1、CA3、DG区的神经元数目增加;而长期应用一氧化氮合酶抑制剂L-NAME可抑制大鼠寻台潜伏期的缩短和nNOS、c-fos基因的表达,同时大脑皮质和海马CA1、CA3、DG区的神经元数目减少。因此我们认为长时间应用NO可促进神经系统c-fos基因的表达和幼鼠神经系统的发育,即可塑性的变化,继而影响大鼠的学习记忆功能。     

L-精氨酸和一氧化氮抑制剂对大鼠血管钙化的影响

观察给予一氧化氮合酶(NOS)的抑制剂左旋硝基精氨酸(L-NNA)或底物L-精氨酸(L-Arg)对血管钙化的影响。利用维生素D3和尼古丁制备大鼠血管钙化模型，测定大鼠尾动脉压，血管钙含量、碱性磷酸酶活性及^45Ca沉积；并检测血管组织的L-Arg转运，NOS活性及NO2^-和cGMP含量。发现钙化大鼠血压略升高；动脉钙含量、ALP活性及^45Ca沉积明显增加，von Kossa染色可以看到明显的钙化颗粒；钙化血管组织NOS活性升高；NO和cGMP含量均减少。给予L-NNA或L-Arg后，与单纯钙化组相比，L-NNA干预组的L-Arg转运、NOS活性及NO和cGMP的含量均降低；而L-Arg干预组上述指标的变化正相反。同时，L-NNA干预组的钙化程度比钙化组加重，而L-Arg干预组的钙化程度比钙化组减轻；提示血管钙化时NO—NOS—cGMP途径发生紊乱，干预NO—NOS—cGMP途径可以影响钙化的进程。     

DADLE对大鼠急性全脑缺血再灌注继发肺损伤的作用

 目的：通过建立大鼠急性全脑缺血再灌注模型,观察肺组织超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量及肺组织光镜、电镜病理变化,探讨δ阿片受体激动剂DADLE对急性肺损伤的保护作用。方法：SD大鼠30只随机分为假手术（sham）组、模型（I/R）组和DADLE处理组。采用改良的二血管阻断加低血压法建立全脑缺血再灌注模型。DADLE处理组（n=10）于再灌注前经左侧颈静脉注射DADLE 5 mg/kg,再灌注120 min后,取肺组织,光镜、电镜观察其病理学改变及检测肺组织SOD活性、MDA含量。右侧股动脉取血测定氧分压,计算氧合指数。结果：I/R组与 sham组比较,肺脏表现为肺泡间隔增宽,毛细血管扩张充血,肺胞腔内及血管周围中性粒细胞浸润,Ⅱ型上皮细胞表面微绒毛明显减少,肺胞腔及气管腔均有浆液渗出,大鼠肺组织SOD活性降低和MDA含量升高。DADLE处理组与I/R组比较肺脏充血减轻,肺组织损伤程度明显减轻,中性粒细胞浸润有所减少,SOD活性升高和MDA含量降低。DADLE处理组动脉血氧分压和氧合指数有升高趋势,与I/R组比较差异有统计学意义。结论：大鼠急性全脑缺血再灌注模型对肺有不同程度的损伤,DADLE可减轻急性肺损伤,对肺组织提供一定的保护作用。     

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.