基质金属蛋白酶在心肌缺血大鼠心室间质重构中的作用

目的:探讨大鼠心肌缺血后心肌间质基质金属蛋白酶(MMPs)活性变化与心室间质重构的关系。方法:用异丙肾上腺素(ISP)复制大鼠心肌缺血模型,用酶谱法测定心肌间质MMPs活性,氯胺T法测定胶原含量,免疫组化法测定I/III胶原比例,电镜观察心肌超微结构。结果:心肌缺血组(M组)MMP-2活性在1、2、4周分别是对照组(C组)的5.8倍、2.3倍(P＜0.01)和1.7倍(P＜0.05),MMP-9活性则分别是对照组的4.9倍、1.9倍(P＜0.01)和1.4倍(P＜0.05)。胶原含量、I/III胶原比例在2周、4周时均显著高于对照组。电镜见缺血组心肌细胞坏死、间质胶原大量增生、结构紊乱。结论:心肌缺血后心肌间质内MMPs活性升高,可能是心室重构的重要原因。     

大鼠急性心肌梗死心室重塑中细胞因子与胶原的变化

目的:探讨大鼠急性心肌梗死（MI）后心室重塑过程细胞因子与胶原分子的关系。 方法:制备雄性Wistar大鼠心肌梗死和假手术对照模型，于手术后3 d、1 w、4 w分别观察不同时点梗死区和非梗死区的Ⅰ、Ⅲ型胶原及炎症因子的mRNA变化。 结果:心肌梗死后第3 d胶原（Ⅰ、Ⅲ型胶原）和细胞因子（TGF-β1、TNF-α）皆上升，梗死区Ⅰ、Ⅲ型胶原在第4周仍然比非梗死区为高，TGF-β1、TNF-α在第1周达到高峰后逐渐下降但仍高于同期假手术组（P＜0.01），相关性分析提示梗死区和非梗死区TGF-β1、TNF-α均与Ⅰ、Ⅲ型胶原存在相关（P<0.01）。 结论:炎症因子参与心室重塑的病理生理过程，干预细胞因子可能作为早期防治心室重塑的手段。     

心肌细胞与胶原材料复合再造组织工程心肌移植心肌梗死大鼠的心肌电生理变化

背景：组织工程化心肌组织移植可修复大鼠心肌梗死。 目的：应用微电极阵标测技术分析心肌细胞与胶原材料复合组织工程再造心肌移植心肌梗死大鼠的心肌电生理特性。 方法：将成年SD大鼠随机分组：假手术组、模型组、移植组。后2组制作心肌梗死动物模型,假手术组仅开胸不结扎冠状动脉,移植组造模后移植心肌细胞与胶原材料复合组织。应用微电极阵标测技术记录心室肌场电位振幅,激活-恢复时间及激动传导时间。 结果与结论：①心室肌场主波振幅：与模型组相比,移植组梗死区、对立区及周围区部位增高(P < 0.05)。②激活-恢复时间：模型组与移植组梗死区与梗死周边区均明显延长,且梗死周边区小于梗死区(P < 0.05)。与模型组相比,移植组梗死区、对立区及周围区部位激活-恢复时间缩短(P < 0.05)。③心室前壁激动传导时间：移植组高于假手术组,但低于模型组(P < 0.05)。表明移植的心肌细胞/胶原复合体能改善心肌梗死大鼠心室肌收缩功能及电传导时间,部分修复心脏功能。     

洛沙坦对急性心肌梗塞后大鼠心肌间质金属蛋白酶活性的影响

目的:探讨急性心肌梗塞后,梗塞区心肌间质金属蛋白酶(MMPs)活性的动态变化及洛沙坦对其的影响。方法:结扎SD大鼠冠状动脉前降支复制急性心梗模型,随机分成对照组和用药组。采用MPA-V型多导生物信号分析系统监测血流动力学指标;采用酶谱法测定54kD间质金属蛋白酶1(MMP-1)、58kD和62kD间质金属蛋白酶2(MMP-2)的活性;采用氯氨T法测定胶原蛋白的含量。结果:梗塞区MMPs活性表现出-过性升高,第3d比假手术组高4.5倍,第7d高6.5倍达高峰,然后下降,第14d降至2倍,第42d仍高1.5倍。用药组MMP-1比同时间点对照组降低33%,MMP-2低至50%;左室重量与体重之比(LVW/BW),第14d和第42d明显低于对照组(P<0.01);梗塞区胶原密度第42d显著低于假手术组(P<0.01)。用药组心脏舒张末期压力于第3d一过性高于对照组,第7、14、42d均低于对照组。收缩压最大上升速度高于对照组(P<0.05)。结论:心肌梗塞后梗塞区MMPs被激活,加速胶原分解代谢;洛沙坦降低MMPs活性,降低胶原分解代谢,同时抑制胶原合成代谢,使心梗后期胶原含量降低,具有改善心脏功能,保护心肌的作用更多     

心肌梗死大鼠心室重塑的动态观察

目的：探讨大鼠心肌梗死（MI）后细胞因子TGF—β1及心室重塑指标动态变化及其与重塑的关系。方法：结扎冠脉左前降支建立心肌梗死（MI）模型并设立假手术对照组。术后3天、1周、4周和24周检测血流动力学和组织形态学及胚胎基因（B肌球蛋白重链），Ⅰ、Ⅲ型胶原和TGF—β1的mRNA水平。结果：与假手术组相比，MI组血流动力学改变明显。心肌梗死后第3天胚胎基因β-MHC、胶原、TGF-β1都上升，一直持续到第4周。梗死区Ⅰ、Ⅲ型胶原在第4周仍然比非梗死区高，即使在第24周非梗死区的胶原水平仍然高于假手术组。TGF—β1在第1周达到高峰后逐渐下降到第24周时非梗死区与假手术组相比有统计学差异（P〈0．01），相关性分析提示梗死区TGF-β1与Ⅰ、Ⅲ型胶原、β-MHC存在相关；非梗死区TGF-β1与Ⅰ、Ⅲ型胶原存在相关。结论：TGF—β1参与心室重塑病理生理过程并且可能是心室重塑的病因之一。     

兔心肌梗死1周及2月后心室肌细胞瞬间外向钾电流的变化

目的:研究心肌梗死后心室肌细胞瞬间外向钾电流(I_to)的变化。方法:采用结扎兔冠状动脉左前降支的方法复制心肌梗死动物模型,酶解法分离单个心室肌细胞,应用膜片钳全细胞记录方法,观察心肌梗死后1周及2月心外膜梗死区及非梗死区心室肌细胞I_to的变化。结果:①非梗死区2月组心肌细胞膜电容明显大于对照组,P＜0.05。②梗死区I_to电流密度(+60mV时)的对比显示:对照组为(17.4±5.2)pA/pF(n=16),梗死区1周组为(7.5±2.4)pA/pF(n=12),明显低于对照组(P＜0.01)。梗死区2月组为(10.6±4.1)pA/pF(n=18),明显低于对照组(P＜0.01),但高于梗死区1周组(P＜0.05)。③非梗死区2月组I_to电流密度为(13.2±4.1)pA/pF(n=23),明显低于对照组(P＜0.05),但高于梗死区2月组(P＜0.05)。结论:心肌梗死可引起心室肌细胞I_to电流密度下降,而且不同区域之间(梗死区及远离梗死区)也存在电生理的异质性,可能是导致心肌梗死后出现折返性室性心律失常的原因。心肌梗死后2月梗死区I_to的下降有恢复倾向。     

激活的巨噬细胞心肌移植改善大鼠缺血再灌注引起的心肌梗死后心室重塑作用

目的观察激活的巨噬细胞(MΦ)心肌移植的旁分泌效应对心肌梗死(MI)后心肌组织修复作用,探讨MΦ心肌修复机制。方法用苯妥英钠(PHT)激活培养的Wistar大鼠腹腔MΦ后进行心肌缺血/再灌注心肌梗死模型Wistar大鼠心肌移植,分为急性心肌梗死(AMI)对照(AMI)、PHT腹腔注射、MΦ移植(MΦ)、激活的MΦ移植(MΦ-PHT)及假手术组。于移植后第7、28天检测各组模型动物心室膨展指数、纤维面积、非梗死区心肌细胞横截面积(CSA)、梗死区小动脉/毛细血管密度,用Western blot分析术后7 d天梗死区血管内皮生长因子(VEGF)、碱性成纤维细胞生长因子(bFGF)蛋白表达水平。结果与AMI组比较,PHT、MΦ、MΦ-PHT组术后28 d膨展指数、纤维面积、非梗死区CSA均显著减少(P<0.05),小动脉密度显著增加(P<0.05);与MΦ组比较,移植激活的MΦ大鼠7 d梗死区VEGF、b-FGF蛋白表达水平均显著增高(P<0.05),术后7、28 d小动脉密度/毛细血管密度增加;术后28 d心肌纤维面积显著缩小(P<0.05)。结论 MI后早期心肌移植激活的巨噬细胞可能通过旁分泌细胞因子,促进组织...     

同种异体脂肪组织源性间质干细胞移植治疗大鼠急性心肌梗死

目的：建立体外分离扩增脂肪组织源性间质干细胞方法，并探讨同种异体脂肪干细胞移植治疗大鼠心肌梗死的效果及可行性。方法: 18只雄性SD大鼠随机分为假手术组、急性心肌梗死对照组（AMI组）及AMI+细胞移植组。分离大鼠腹部脂肪组织干细胞，体外扩增，BrdU标记后于结扎左冠状动脉前降支后1h移植入梗死心肌，移植后4周进行血流动力学检测心功能并取出心脏进行病理切片观察和免疫组织化学染色检测移植细胞在梗死心脏中的定居、存活情况。结果: 大鼠腹部脂肪组织可分离培养出大量间质干细胞。细胞移植治疗组左心室收缩压高于AMI对照组（P＜0.01），舒张末压显著降低（P＜0.01），左心室内压最大上升、下降速率明显加快（P＜0.05）；病理组织切片显示梗死边缘区心肌面毛细血管计数明显增加，梗死区心肌组织内及毛细血管壁中均可见移植标记细胞。结论: 脂肪组织可作为干细胞又一新的来源，同种异体脂肪干细胞移植治疗AMI有效、可行。     

激活PPARδ对梗死心肌MMP-9及纤连蛋白表达的影响

目的: 研究过氧化物酶体增殖物激活受体δ(PPARδ)激动剂GW610742X对梗死心肌重塑过程中基质金属蛋白酶9(MMP-9)及细胞间基质纤连蛋白(FN)表达的影响。方法: 雄性Wistar大鼠,分为对照组、假手术组、心肌梗死(MI)组和MI+GW610742X(GW)组。结扎大鼠左冠状动脉建立MI模型,GW组予以GW610742X(100 mg·kg^-1·d^-1)喂养。术后3个月检测各组大鼠左心室游离壁(LVFW)中PPARδ、MMP-9及FN的mRNA及蛋白表达;免疫荧光法检测LVFW中FN的分布。结果: MI组术后3个月LVFW心肌有不同程度的坏死及纤维化。MI组PPARδ表达高于对照组、假手术组及GW组(P＜0.01),GW组PPARδ表达低于对照组及假手术组(P＜0.05);MI组及GW组MMP-9表达高于对照组及假手术组,FN表达低于对照组及假手术组(P＜0.01或P＜0.05)。GW组MMP-9表达低于MI组(P＜0.05),FN表达高于MI组(P＜0.01)。假手术组与对照组MMP-9及FN的表达无显著差异(P＞0.05)。结论: 梗死心肌重构过程中,MMP-9表达上调,FN被降解;激活PPARδ 可能通过抑制MMP-9的表达,减轻FN的降解,从而改善心肌重塑。     

阿托伐他汀对糖尿病大鼠急性心肌梗死后心功能及HGF/c-Met信号通路的影响*

 目的： 糖尿病患者急性心肌梗死（AMI）后的心室重构及心功能恶化较非糖尿病者更为明显。本研究旨在观察阿托伐他汀对糖尿病大鼠AMI后心肌细胞凋亡、心室重构及心功能的影响,并探讨其作用是否与肝细胞生长因子及其受体 (HGF/c-Met)信号通路有关。方法: 70只雄性SD大鼠经链脲霉素 (STZ, 65 mg/kg)腹腔注射,诱导糖尿病大鼠模型。8周后对糖尿病大鼠结扎左冠状动脉前降支构建AMI大鼠模型,术后存活32只大鼠随机分为2组：AMI对照组(n=16)和阿托伐他汀干预组(n=16, 阿托伐他汀20 mg·kg-1·d-1),并在糖尿病大鼠中设假手术组(n=11),术后24 h予以灌胃给药。2周后比较各组大鼠心功能、心肌组织病理改变、心肌细胞凋亡、HGF和c-Met mRNA及蛋白表达差异。结果: (1) AMI对照组心功能显著低于假手术组（P<0.05）,胶原容积分数、心肌细胞凋亡指数、HGF及c-Met mRNA及蛋白表达均显著高于假手术组（P<0.05）;(2) 阿托伐他汀干预组的胶原容积分数和心肌细胞凋亡指数显著低于AMI对照组（P<0.05）,心功能、HGF及c-Met mRNA及蛋白表达均显著高于AMI对照组（P<0.05）。结论: 阿托伐他汀对糖尿病大鼠AMI后心肌细胞凋亡、心室重构及心功能具有显著改善作用;HGF/c-Met信号通路在AMI后会激活,阿托伐他汀的上述作用机制可能与其进一步增强HGF/c-Met信号通路有关。     

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.     

Intestinal helminthiasis in school children in Haiti in 2002

A survey on intestinal helminths in school children was conducted in Haiti in 2002. This first nationwide study involving the entire country was stratified by department according to urban and rural zones using the cluster method. Focusing on elementary school children (n=5792; age range 3 to 20 years), it involved 26 urban and 49 rural schools randomly selected. Stools were preserved in formalin and examined by the Ritchie technique. Thirty-four per cent of stools (1981/5792) tested positive for intestinal helminths with the following parasites identified: Ascaris lumbricoides (27.3%), Trichuris trichiura (7.3%), Necator americanus (3.8%), Hymenolepsis nana (2%), Taenia sp. (0.3%) and Strongyloides stercoralis (0.2%). The helminth prevalence was higher in rural (38.4%) compared to urban areas (30%). There was no significant difference in prevalence by sex and age. The importance of geohelminths changed from one department to another with the highest prevalence found in the Southern department of Grande Anse (73.7%) and the lowest prevalence in the Center department (20.6%). Five out of the country's nine departments had a similar prevalence varying from 25.5% to 28.2%. Intestinal helminthic polyparasitism was observed in a percentage of infested school children comprise between 3.4% and 28.6% according in relation to the geographical area. A program to fight against geohelminths in school children should be initiated as a public health priority. Albendazole is the drug of choice. Frequency of drug distribution should be based on the prevalence of geohelminths in each department.     

Experience in adult population in dengue outbreak in Delhi

A dengue outbreak has recently hit the Indian capital. We studied the clinical profile of adult patients. Five hundred and sixty patients of dengue infection were admitted in a specially created ward according to the criteria laid down by WHO. Haematemesis (28.28%), epistaxis (26.78%) and malena (14.28%) were some of the common presentations. Similarly lymphadenopathy, especially cervical (30.89%), palatal rashes (26.96%) and hepatomegaly (23.75%) were the most commonly encountered findings on physical examination. Most of the cases were of dengue fever with haemorrhage and only 2.5% cases were classified under dengue haemorrhagic fever or dengue shock syndrome. The average hospital stay was 3.4 days but only 9.8 hours in the eleven patients who died, suggesting their late arrival in preterminal situation giving little time for resuscitation. Thrombocytopenia was not a feature and only 12.85% patients had platelet count less than 70,000/cmm. Most of the patients who were admitted with thrombocytopenia, showed normalization in their platelet counts in next few days. Serological examination demonstrated evidence of recent dengue infection in 41.17% patients. Few patients required blood or platelet concentrate transfusion. Eleven patients died, three due to DIC, one of intracranial haemorrhage and seven due to massive gastric haemorrhage. Rest of the patients recovered completely. Thus we can conclude that recent outbreak in Delhi was of dengue fever with haemorrhage and mortality was very low in patients who came early to the hospital.     

Changes in the hypothalamic nuclei in in experimental allergy

Summary In rabbits subjected to prolonged sensitization and in which the Arthus phenomenon was induced there was a marked reaction of the hypothalamic nuclei. Staining by Gomori's method indicated a cellular swelling, loss of granules, and protoplasmic vacuolization in the supraoptic nucleus. There was a considerable increase in the size of the cross-sectional area of the cells. The same effects were much less well shown in the paraventricular nucleus. These results show that marked signs of increased neurosecretion developed in the animals at the height of the Arthus phenomenon.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten Éksperimental'noi biologii i Meditsiny, Vol. 55, No. 4, pp. 110–113, April, 1963.     

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.