Contact sensitivity to acrylate compounds in guinea pigs

As reports of contact dermatitis in humans due to acrylate compounds have increased considerably in recent years, it was decided to investigate the ability of these chemicals to evoke contact sensitivity skin reactions in guinea pigs. 21 different acrylate and methacrylate compounds were scanned for their ability to induce contact sensitivity, using 5 different sensitization protocols. Contact reactions of varying intensities were produced to all the mono-, di- and triacrylates tested. However, it was not possible to sensitize guinea pigs to any methacrylates. It would appear that guinea pigs cannot be contact sensitized to acrylate chemicals that are substituted on carbon 2.     

豚鼠胎仔肾脏巨细胞病毒感染的实验研究

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。     

Effects of the endothelin-1 receptor antagonist tezosentan on renal blood flow and diuresis during prolonged increased intra-abdominal pressure

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.     

不饱和脂肪酸对豚鼠胃窦环行肌细胞毒蕈碱电流的影响

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。     

Plasma cytokines do not reflect expression of pro- and anti-inflammatory cytokine mRNA at organ level after cardiopulmonary bypass in neonatal pigs

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.     

Hypoglycaemic effect of Opuntia lindheimeri Englem in a diabetic pig model

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.     

Long-term,low-level exposure of guinea pigs and marmosets to sarin vapor in air: lowest observable effect level

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.     

我国实验用豚鼠面神经核的立体定位坐标值

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．     

乳猪小肽螯合铁的补铁效果

采用小肽螯合铁作为补铁剂,妊娠和泌乳母猪以及乳猪为研究对象,测定母猪初乳铁的含量,乳猪5、10、14和21日龄的血红蛋白（Hb）以及乳猪14和21日龄的血清铁蛋白（SF）浓度.结果表明,小肽螯合铁比硫酸亚铁能够更有效地进入母乳,母猪补小肽铁可增加乳猪铁的获得,但不能解决乳猪的缺铁问题;乳猪补小肽螯合铁不但有较高的Hb水平,而且体内铁储备量高于补右旋糖苷铁,可满足乳猪铁的需要.     

针刺对形觉剥夺性近视豚鼠巩膜形态及组织中HIF-1α、SOD、MDA水平的影响

目的 探究针刺对形觉剥夺性近视(FDM)豚鼠巩膜组织形态特点及巩膜组织中缺氧诱导因子1α(HIF-1α)、超氧化物歧化酶(SOD)、丙二醛(MDA)水平的影响。方法 选取普通级3周龄健康三色豚鼠72只,随机分为空白组、模型组和针刺组(各24只)。用半透明气球作为眼罩分别固定于模型组和针刺组豚鼠右眼及头面部建立FDM模型,左眼充分暴露作自身对照;针刺组在豚鼠模型建立当天起,于每日相同时间对豚鼠进行针刺和电针干预治疗,空白组豚鼠不做任何干预。记录每组豚鼠造模前、造模后2周及4周的眼轴长度和屈光度。造模后4周处死豚鼠,光学显微镜下观察巩膜形态变化,Western blot检测各组豚鼠巩膜中HIF-1α蛋白表达,比色法测定各组豚鼠巩膜中SOD活力和MDA含量。结果 造模后2周和4周,与空白组比较,模型组及针刺组豚鼠遮盖眼近视屈光度及眼轴长度均明显增加(均为P<0.05);与模型组比较,针刺组豚鼠遮盖眼近视屈光度减小,眼轴增长明显减缓(均为P<0.05)。造模后4周,与空白组比较,模型组豚鼠巩膜厚度明显变薄,胶原纤维分布稀疏,有明显纤维空隙且排列不规则;与模型组相比,针刺组豚鼠巩膜层...