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91.
豚鼠胎仔肾脏巨细胞病毒感染的实验研究   总被引:3,自引:0,他引:3  
目的 探讨豚鼠胎仔肾脏巨细胞病毒感染与妊娠结局的关系。方法 随机选择孕早期豚鼠 2 0只 ,腹腔接种巨细胞病毒 ,观察其妊娠结局 ,分娩后 2 4h内处死新生豚鼠。用地高辛标记的巨细胞病毒晚期mRNA三相探针进行原位杂交 ,检测豚鼠胎仔肾脏内巨细胞病毒负荷量及分布情况。结果  2 0只母豚鼠共妊娠 6 3只胎仔 ,其中足月活产并存活到 2 4h以上的胎仔 4 2只 ,流产等异常胎仔 2 1只。原位杂交检测正常胎仔巨细胞病毒感染率 7 1% (3/ 4 2 )、平均吸光度 (A)为 0 10 5±0 0 5 2 ,异常胎仔巨细胞病毒感染率 2 8 6 % (6 / 2 1)、平均A为 0 15 8± 0 0 4 7,两者平均A比较 ,差异有显著性 (P <0 0 5 )。杂交阳性信号主要分布在肾小管和集合管上皮细胞。结论 巨细胞病毒晚期mRNA主要在肾小管和集合管上皮细胞中表达 ,其表达水平与异常妊娠结局相关。  相似文献   
92.
BACKGROUND: It has earlier been shown that increased intra-abdominal pressure (IAP) reduces renal blood circulation and urine output both clinically and experimentally. The aim of this study was to investigate the effect of endothelin-1 inhibition by the endothelin-1 receptor antagonist tezosentan on renal blood circulation and diuresis in pigs subjected to prolonged increased intra-abdominal pressure. MATERIAL AND METHODS: The IAP in domestic pigs was maintained at 30 mmHg for 3 h. One group of 10 animals was pre-treated with the endothelin-1 receptor antagonist tezosentan, and then received continuous infusion of tezosentan throughout the experiment. Another group of 10 animals served as control. We measured renal cortex blood flow, plasma renin activity, blood concentrations of endothelin-1 and aldosterone, and diuresis. RESULTS: The administration of tezosentan to pigs with an IAP of 30 mmHg was followed by reduced arterial pressure, reduced renal cortex blood flow, and reduced diuresis. The plasma renin activity increased markedly, but neither renal vascular resistance nor blood concentration of aldosterone did change significantly. CONCLUSION: Tezosentan reduced the arterial blood pressure, which resulted in decreased renal cortex blood flow, and aggravation of the oliguria usually observed under increased IAP. The plasma renin activity increased, but this was not followed by changes in renal vascular resistance, or blood concentration of aldosterone. The results indicate that drugs, which reduce the arterial pressure, may be harmful to the kidneys under increased IAP.  相似文献   
93.
不饱和脂肪酸对豚鼠胃窦环行肌细胞毒蕈碱电流的影响   总被引:2,自引:0,他引:2  
目的:研究外源性不饱和脂肪酸对豚鼠胃窦平滑肌细胞素毒蕈碱电流的影响及其作用机制。方法:利用膜片箝技术的全细胞记录法在急性分离的胃窦环行肌细胞上记录毒蕈碱电流。结果:在细胞外灌流液中给予花生四烯酸(arachidonic acid,AA)明显抑制I_cch,并具有量效关系:当AA的浓度在1。3和μmo1/L时,分别抑制I_cch至46%±8%,23%±5%和3.8%±0.9%;另一种不饱和脂肪酸,亚麻酸(linoleic acid,LA)也抑制I_cch,在1,5和10μmo1/L浓度分别抑制I_cch至3.8%±0.9%,35%±5%和67%±9%;用H-7(蛋白激酶C抑制剂)100μmo1/L预处理10-15分钟以后,AA分别抑制I_cch至5.5%±0.7%和3.0%±1.0%。结论:不饱和脂肪酸直抑制毒蕈碱电流,且抑制程度与不饱和脂肪酸链中的双键数目有关。  相似文献   
94.
BACKGROUND: Plasma concentrations of inflammatory markers are increased in response to the trauma of cardiac surgery and cardiopulmonary bypass (CPB). It is, however, unknown whether the plasma cytokine levels and cytokine mRNA expression at organ level reflect each other. METHODS: Twenty-six piglets (17-19 days) were allocated to the sham-group (sternotomy only, n = 13) or to the CPB-group (sternotomy, 120 min CPB procedure with 60-min aortic cross-clamp, n = 13). The pigs were observed for 0.5 h or 4 h post-CPB. Plasma levels of IL-1beta, IL-6, IL-8 and IL-10 and mRNA expression of TNF-alpha, IL-1beta, IL-6, IL-8, IL-10 and iNOS in organs were registered with concomitant changes in oxygenation index (OI) and expiratory nitric oxide (NO). RESULTS: In pigs killed 0.5 h post-CPB there was a significant increase in IL-10 mRNA in the lungs and kidneys compared with the sham-group. IL-1beta mRNA was detectable in the kidneys and lungs of the CPB-pigs, while IL-6 mRNA was up regulated only in lungs. In pigs killed 4 h post-CPB a significantly higher IL-6 mRNA was found in heart tissue and a lower IL-10 mRNA was found in lungs of CPB pigs compared with the sham-group. There was a concomitant significant increase in OI and increased plasma IL-8 and IL-10 concentrations in the CPB-pigs compared with the sham-pigs. CONCLUSION: The cytokine mRNA expression pattern was very different for the pigs killed already 0.5 h after the CPB procedure compared with the pigs killed 4 h post-CPB. The plasma cytokine levels poorly reflected mRNA expression of the pro- and anti-inflammatory cytokines.  相似文献   
95.
Hypoglycaemic effect of Opuntia lindheimeri Englem in a diabetic pig model   总被引:2,自引:0,他引:2  
The hypoglycaemic activity of Opuntia lindheimeri Englem. was investigated in non-diabetic (control pigs) and streptozotocin-induced diabetic pigs using an enteral (oral) route of administration. Following the administration of O. lindheimeri extract (0, 250 or 500 mg/kg body weight), blood glucose concentrations in control pigs fluctuated around initial baseline concentrations, but were not consistently affected by either the dose of O. lindheimeri or by the time following administration. In contrast, administration of O. lindheimeri extract to STZ-treated pigs resulted in both a dose- (p < 0.001) and time-dependent (p < 0.001) decrease in blood glucose concentrations. The hypoglycaemic effect of the extract was apparent within 1 h of administration, with maximal effects occurring at 4 h after administration. These results confirm the hypoglycaemic effect of O. lindheimeri extract in a diabetic pig model. In addition, given the physiological similarities of the pig to humans, this model will be of tremendous use in assessing the long-term effects of Opuntia administration on the secondary problems associated with diabetes.  相似文献   
96.
The effect of temperature on the development of sulphur mustard (HD)-induced toxicity was investigated in first passage cultures of human skin keratinocytes and on hairless guinea pig skin. When cells exposed to HD were incubated at 37 degrees C, a concentration-dependent decline in viability was observed that was maximal by 2 days. In contrast, no significant HD-induced toxicity was evident up to 4 days posttreatment when the cells were incubated at 25 degrees C. However, these protective effects were lost by 24 h when the cells were switched back to 37 degrees C. The protective effects of hypothermia were also demonstrated when apoptotic endpoints were examined. The HD concentration-dependent induction of fragmented DNA (as quantitated using soluble DNA and the TUNEL reaction), morphology, and p53 expression were all significantly depressed when cell cultures were incubated at 25 degrees C compared to 37 degrees C. When animals were exposed to HD vapour for 2, 4, and 6 min and left at room temperature, lesions were produced whose severity was dependent on exposure time and that were maximal by 72 h posttreatment. Moderate cooling (5-10 degrees C) of HD exposure sites posttreatment (4-6 h) significantly reduced the severity of the resultant lesions. However, in contrast to the in vitro results, these effects were permanent. It appears that the early and noninvasive act of cooling HD-exposed skin may provide a facile means of reducing the severity of HD-induced cutaneous lesions.  相似文献   
97.
Realistic scenarios for low-level exposure to nerve agents will often involve exposures over several hours to extremely low doses of agent. In order to expose animals to the lowest controllable concentrations of agent and to increase exposure times until a lowest observable effect level (LOEL) becomes measurable, a validated system was developed for exposing conscious animals to 0.05-1.0 microg/m(3) (8-160 ppt) of sarin and other nerve agents. Based on cold trapping of sarin from the exposure air, the concentration could be measured semicontinuously, at 4-min time intervals by means of gas chromatography. We found that the LOEL upon a 5-h whole body exposure of guinea pigs and marmosets to sarin vapor corresponds with the measurement of an internal dose by means of fluoride-induced regeneration of sarin from phosphylated binding sites in plasma, mostly BuChE. For guinea pigs the LOEL was observed at Ct = 0.010 +/- 0.002 mg/min/m(3), whereas a Ct of 0.04 +/- 0.01 mg/min/m(3) was established for the LOEL in marmosets. These levels are several orders of magnitude lower than those based on classical measurement of depressed cholinesterase activities. At low exposure levels of guinea pigs and marmosets (< or =1 microg/m(3)), a reasonable linearity was observed between exposure dose and internal dose. The data were addressed in the light of the recently recommended occupational exposure limits to sarin for workers without respiratory protection, which suggests that the exposure limits should be reconsidered if the slightest inhibition of cholinesterases should be prevented.  相似文献   
98.
Purpose. To determine whether a new formulated albuterol aerosol could sustain inhibition to bronchoconstriction for approximately one day in guinea pigs challenged with carbachol. Methods. Large and porous particles, comprising a combination of endogenous or PDA-approved excipients and albuterol sulfate, were prepared by spray drying using a NIRO portable spray drier. The anesthetized animals inhaled 5 mg of large porous or small nonporous particles by forced ventilation via cannulae inserted in the lumen of their exposed tracheae. At regular intervals over a period of 36 hours after drug delivery, airway resistance was determined in response to carbachol challenge dose. Results. Whereas inhalation of small nonporous albuterol particles protected from the carbachol-induced bronchoconstriction for up to 5 hours, inhalation of large porous albuterol particles produced a significant inhibition of carbachol-induced bronchoconstriction for at least 16 hours. Conclusions. The absence of substantial side effects, verified over a period of 24 hours by evaluating cardio-respiratory parameters as well as pulmonary inflammation, supports the utility of large porous albuterol particles for sustained therapies in asthma and other types of lung disease.Dr. Ben-Jebria is also affiliated with  相似文献   
99.
我国实验用豚鼠面神经核的立体定位坐标值   总被引:2,自引:0,他引:2  
目的:确定我国实验用豚鼠面神经核(FN)中心的立体定位坐标值.方法:Nissl染色、HRP逆行追踪方法及立体定位仪确定FN立体定位坐标值;利用Nissl染色在连续切片上确定豚鼠面神经核的外径.结果:体重300g~650g豚鼠的FN中心坐标值为P:(2.4±0.1)mm,LL/RL:(2.0±0.07)mm,H:(-1.9±0.08)mm;FN的前后径:(1.5±0.09)mm,左右径:(1.3±0.07)mm,上下径:(1.4±0.06)mm结论:确定了我国实验用豚鼠FN的立体定位坐标值,为面神经的研究提供了便利条件.  相似文献   
100.
Dosage regimen adjustments because of poor renal function are often assumed to be unnecessary for extensively metabolized antidepressants. This assumption is being increasingly questioned in recognition of the role of active drug metabolites. The purpose of this study was to assess the steady-state accumulation of the new antidepressant bupropion and its three major basic metabolites in guinea pigs, with and without experimentally-induced renal guinea pigs, with and without experimentally-induced renal failure. Two groups of guinea pigs were treated by intraperitoneal (IP) implantation of mini-osmotic pumps containing bupropion hydrochloride. Immediately after surgery, one group of animals received an injection of uranyl nitrate. After 4 days, all animals were sacrificed by decapitation following blood removal by cardiac puncture. Analysis of plasma and brain samples by high performance liquid chromatography (HPLC) for concentrations of bupropion (BUP) and its major basic metabolites, the erythro-amino alcohol (EB), the threo-amino alocohol (TB) and the hydroxy metabolite (HB) revealed greater accumulation of BUP, TB, and HB in plasma and brain of the animals with renal failure compared to controls. No difference was found between groups in the concentrations of the EB metabolite. As the guinea pig shows a BUP and metabolite plasma concentration profile similar to that seen in human studies, these results suggest that further studies of bupropion and its major metabolites are warranted in patients with impaired renal function to assess possible excessive drug and metabolite accumulation.  相似文献   
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