前房注射卡波姆建立大鼠高眼压模型的观察

目的　前房注射卡波姆建立大鼠高眼压模型，观察卡波姆升眼压效果及对大鼠眼前节和视网膜的影响。方法　随机选取30只SD大鼠，注射前3 d早晚测量基线眼压。右眼定为实验眼，左眼定为对照眼，右眼放出房水后将30 μL的5 g·L^-1卡波姆混悬液注入前房，每日早10时、晚22时在大鼠清醒状态下测量眼压。每周进行双眼眼前节照相并对比。4周末处死26只大鼠（另4只持续观察眼压变化至注射后9周）并取双眼眼球行HE染色，观察实验眼与对照眼视网膜形态，对比视网膜厚度及房角形态。结果　注射前，实验眼白天和夜间眼压分别为（11.10±0.90）mmHg（1 kPa=7.5 mmHg）和（11.92±1.07）mmHg，对照眼分别为（11.22±1.07）mmHg和（11.76±1.08）mmHg；实验眼与对照眼相比，白天、夜间眼压差异均无统计学意义（均为 P＞0.05）；白天与夜间眼压相比，实验眼、对照眼差异均有统计学意义（均为P<0.05）。卡波姆在前房中呈现出弥散型和沉积型两种存在方式，弥散型和沉积型大鼠1周内眼压分别为（17.83±3.54）mmHg和（13.00±1.55）mmHg，两者相比差异具有统计学意义（P＜0.05）。注射后第1天至第19天，实验眼与对照眼白天眼压相比差异均具有统计学意义（均为P＜0.05）；注射后第1天至第27天，实验眼与对照眼夜间眼压相比差异均具有统计学意义（均为P＜0.05）。实验眼视网膜形态发生改变，注射后4周视网膜厚度为（254.70±21.80）μm，与对照眼的（346.73±24.63）μm相比，差异有统计学意义（P=0.00）。实验眼前房充满卡波姆及虹膜的混合成分，紧贴角膜内皮并延伸至房角，堵塞小梁网结构，正常虹膜形态消失；对照眼房角形态正常。结论　前房注射卡波姆建立大鼠高眼压模型，可维持高眼压4周以上，昼夜眼压差异较为明显，夜间眼压较白天更高，4周后视网膜出现高眼压损伤后的表现。     

Toxicological evaluation of Yulangsan polysaccharide in Wistar rats: A 26-week oral gavage study

Although numerous studies have proven the medicinal values of Yulangsan polysaccharide (YLSP), the toxicity of this active ingredient is unknown. In the acute toxicity study, a single oral administration of 24 g/kg YLSP caused neither toxicological symptoms nor mortality, and the LD₅₀ was estimated >24 g/kg. In the chronic toxicity study, we administered doses of 0, 0.6, 1.2 and 2.4 g/kg YLSP in rats by oral gavage for 26 weeks followed by a 3-week recovery period. There was no mortality or remarkable clinical signs observed during this 26-week study. Additionally, there were no toxic differences in the following parameters: body weight, food consumption, hematology, clinical biochemistry, organ weight, and macroscopic findings. There were no adverse effects on histopathology observed in males or female rats treated with YLSP. Based on the results, the no-observed-adverse-effect-level of YLSP in rats is greater than 2.4 g/kg when administered orally for 26 consecutive weeks.     

丹参对持续癫痫幼鼠脑损伤保护作用的实验研究

目的 探讨丹参对持续癫痫发作诱发幼鼠脑神经元损伤是否具有保护作用。方法 皮下及腹腔注射贝美格针诱发健康幼龄鼠癫痫持续状态发作。光镜下观察神经元病变情况；电镜观察海马神经元超微结构的改变。结果 持续癫痴组幼鼠脑组织光镜下可见明显的神经元病变。电镜下可见海马区神经元的超微结构病变。丹参治疗组神经元病变均轻于持续癫痴组；而正常对照组未见类似病变。结论 丹参在组织、细胞和亚细胞水平对持续癫病幼鼠脑神经元损伤具有一定的保护作用，为临床有效防治小儿惊厥性脑损伤提供了可靠的实验依据。     

Prevention of Descending Pneumonia in Rats with Perflubron-delivered Tobramycin

OBJECTIVES: Patients undergoing emergent endotracheal intubation are at increased risk for developing pneumonia. Although numerous strategies have been investigated to reduce ventilator-associated pneumonia (VAP), the incidence of VAP and its associated mortality remains high. This investigation tested the hypothesis that LiquiVent (Alliance Pharmaceutical, San Diego, CA-LV) delivered antibiotics (via spray-dried microspheres-SDM) would improve survival in a rat model of descending gram-negative pneumonia. METHODS: Wistar rats (n = 49) were randomized to receive prophylaxis with 1). nothing (controls); 2). intramuscular (IM) tobramycin, 3). intratracheal LV plus SDM shells (vehicle), 4). intratracheal LV plus SDM shells plus IM tobramycin, or 5). intratracheal LV plus SDM containing 1 mg/kg of tobramycin. All interventions were given 24 hours before a bacterial challenge with 10(8) colony-forming units of intratracheal Klebsiella pneumoniae. Mortality at ten days was the sole outcome measure. Survival in individual groups was compared with controls by Fisher's exact test with Bonferroni correction for multiple comparisons. RESULTS: All animals in the control group died of pneumonia within ten days of bacterial inoculation (0% survival). Prophylaxis with either IM tobramycin or SDM vehicle plus IM tobramycin provided no protection (0% survival). This is in sharp contrast to the cohort receiving pretreatment with tobramycin-containing SDM delivered via LV, in which 60% of the animals survived to study completion (p < 0.05). CONCLUSIONS: Prophylaxis with SDM containing antibiotics delivered in low-dose LV provided significant protection in a rat model of descending gram-negative pneumonia. These data support the hypothesis that perfluorocarbon-delivered intratracheal antimicrobials may be useful in the prevention of VAP.     

卡托普利对自发性高血压大鼠血管平滑肌细胞增殖及癌基因和抑癌基因的影响

目的：观察卡托普利（CaP）对自发性高血压大鼠（SHR）血管平滑肌细胞（VSMC）增殖的作用及对原癌基因及抑癌基因的影响。方法：氚-胸腺嘧啶核苷（3H－TdR）参入，电镜，原位来交及Northernblot杂交。结果：CaP在降低SHR血压同时，能减少VSMC的线粒体，粗面内质网及3H－TdR参入量（P<0.01），并能逆转c－fos，c－myc，c－sis原癌基因mRNA表达增强（P<0.05或0.01），p53抑癌基因mRNA表达减弱（P＜0．01）。结论：Cap能抑制SHR的VSMC增殖，与癌基因调控的分子生物学机制有关。     

Dorsal and ventral dopaminergic innervation of the spinal cord: Functional implications

Several studies have demonstrated that a descending dopaminergic pathway innervates the dorsal and the intermediate gray matter of the spinal cord and have suggested that this pathway is involved in pain modulation and in the control of autonomie functions. Other studies have also demonstrated the presence of dopamine (DA) and DA metabolites as well as of DA receptors in the ventral cord. There is also evidence for the implication of DA in the control of motor functions at the spinal level. The occurrence of a dopaminergic innervation in the ventral horn has been, however, disputed until recently. But recent work has demonstrated that the motoneural cell groups in the ventral horn (lamina IX) are a target for descending dopaminergic fibers. In addition, the possibility that DA is a mediator of primary afferent fibers has also been postulated. Finally, the occurrence of dopaminergic cell bodies has been suggested in the spinal cord. This indicates that DA is probably implicated in a complex manner in spinal functions. In the present paper the possible involvement of DA in sensory and in motor functions at spinal level will be discussed in view of neurochemical observations made in polyarthritic rats, in which pain-related behavior and reduction of locomotor activity associated with a marked decrease in mobility, are observed.     

大白鼠尾动脉吻合实验的方法与体会

报告了960次大白鼠尾动脉吻合实验,采用端端吻合法800次,即刻通畅率96.5％,套叠吻合法160次,即刻通畅率100％。作者认为利用大白鼠尾动脉作吻合训练,具有节省动物、可多次操作、无需无菌条件、操作简单易行等优点,并介绍了操作方法和注意点。     

Natural killer cell activity and autologous mixed lymphocyte response of splenic,mesenteric lymph node,and colonic lymphocytes during DMH-induced colon carcinogenesis in the rat

Twoin vitro models of immune surveillance were used to examine the immune status of the gut-associated lymphoid tissue, mesenteric lymph nodes, and spleen during the early stages of 1,2-dimethylhydrazine (DMN)-induced colon tumorigenesis. DMH-and vehicletreated Fischer rats were sacrificed at one of three time points; one week, two months, or five months after cessation of treatment. Colonic, lymph node, and splenic natural killer cell cytolytic activity toward YAC-1 tumor targets and T-cell response to autologous la-induced balstogenesis were measured at each time point. We found little change in natural killer cell activity or T-cell proliferation induced by autologous Ia gene products at these time periods.This investigation was supported in part by grant CA26917 from the National Cancer Institute, Department of Health and Human Services.