Ontogeny of J chain expression in pig lymphocytes

The ontogeny of lymphocytes expressing J chain in the cytoplasm (J+) was studied in pig foetuses by the immunofluorescent technique. Peripheral blood lymphocytes were the first J+ cells in prenatal life. The spleen and lymph nodes contained J+ cells in the last days of gestation. J+ cells were found in the lamina propria of the gut and some glands of conventional but not of germ-free piglets. J chain was not detected on or in cell membranes at any developmental stage.     

Prediction of hepatic graft viability before reperfusion: an analysis of effluent from porcine allografts

Rapid and reliable assessment of hepatic graft viability is important for successful orthotopic liver transplantation (OLTx). OLTx was performed in 11 pairs of pigs via a venovenous bypass. Six of these grafts were transplanted immediately (group A), while the other five were preserved in University of Wisconsin (UW) solution for 24 h and then transplanted (group B). All grafts were flushed with 300 ml of chilled (4°C) Ringer's lactate solution before reperfusion of the graft, when 20 ml of effluent from the graft was collected and the concentrations of ammonia, lactic acid, GOT, and LDH were measured. Four of the six pigs in group A survived longer than 3 days, while the other two pigs died of causes other than graft dysfunction. All five pigs in group B died either of hemoperitoneum or hemodynamic instability due to liver failure. The histology of postperfusion biopsies in group A showed minimal pathological changes, while the grafts in group B revealed moderate to severe ischemic injuries. Ammonia and lactic acid in the effluent of group B were significantly higher than those of group A (1511±216 vs 417±333 g/dl and 114.1±12.2 vs 91.4±12.2 mg/dl, respectively; P<0.05 in both cases). Before reperfusion, the rate of total adenine nucleotides in all of the substances in the graft, which were measured using high performance liquid chromatography (HPLC), inversely correlated with the ammonia levels in the effluent. We conclude that an analysis of the effluent, (i.e. the levels of ammonia and lactic acid), flushed from a hepatic graft before reperfusion could serve as a predictor of hepatic graft viability.     

Binding and specificity of major immunoglobulin classes of preformed human anti-pig heart antibodies

Preformed human anti-pig antibodies isolated from perfused pig hearts were used to analyze the binding of various immunoglobulin classes to cultured pig kidney cells. All anti-pig immunoglobulins (i.e., IgG, IgA, and IgM) were localized on the cell surface by the use of an indirect immunofluorescence technique. Anti-pig immunoglobulins also competed for the pig cell surface epitopes with Griffonia simplicifolia lectin (GS-I-B₄), which is specific for -galactosyl residues. This study provides further evidence that preformed human antibodies recognizing -glactosyl-containing epitopes (anti-gal antibodies) could be an important factor in hyperacute rejection of pig organs.     

Reflex peristalsis in the guinea pig isolated ileum is endogenously controlled by kappa opioid receptors

Summary (1) Reflex peristalsis in the circular muscle of the guinea pig ileum was elicited in vitro by sustained luminal distension of the intestinal wall according to 2 cm H₂O and evaluated in terms of the number of peristaltic waves within 15 min intervals. (2) The poorly -selective opioid antagonist naloxone at concentrations of 10^–7 and 10^–6 mol/l increased the frequency of peristaltic contractions within the first 15 min interval, and thereafter in a declining fashion, by 68 and 88%, respectively. The highly -selective opioid antagonist nor-binaltorphimine behaved similarly. It was, by one order of magnitude, more potent but a little less effective than naloxone, i.e., the maximum effect was 57% increase in peristaltic frequency at 10^–8 mol/l. Concentrations of 10^–7 and 10^–6 mol/l had the same effect as 10^–8 mol/l, and 10^–9 mol/l were ineffective. The highly -selective antagonist CTOP-NH₂ and the highly -selective antagonist ICI 174,864 were ineffective up to 10^–6 mol/l. (3) It is concluded that predominantly opioid receptors are used by endogenous opioids under the present conditions to inhibit reflex peristalsis.     

豚鼠螺旋蜗轴动脉SP能神经的结构

目的 观察豚鼠螺旋蜗轴动脉（ＳＭＡ）ＳＰ能神经支配的特点。方法 采用免疫组织化学ＡＢＣ法结合葡萄糖氧化酶－ＤＡＢ－镍染色技术及免疫透射电镜,探讨Ｐ物质（ＳＰ）在ＳＭＡ上的分布特点。结果 ＳＭＡ近端外膜上存在着大量ＳＰ－ＩＲ阳性神经元,在ＳＭＡ远端外膜上可见大量的ＳＰ－ＩＲ阳性神经纤维,相互交错,呈网状结构。结论 ＳＰ的耳蜗血管的调节过程中可能起着重要作用。     

猪单纯门静脉血流阻断安全时限的研究猪单纯门静脉血流阻断安全时限的研究

目的 通过对猪单纯门静脉血流阻断,全面评估猪耐受门静脉血流阻断的安全时限。方法 将18只健康荣昌种猪随机分为假手术组（SO）、单纯门静脉阻断45min（PVC－45′）、60min（PVC－60′）组,通过对门静脉血流阻断,了解其存活情况、血流动力学改变、肝脏及肠道病理改变等。结果 ①SO、PVC－45′、PVC－60′组长期存活率分别为100％、100％、66．7％;②PVC组阻断前后血流动力学参数波动较大;③PVC－45′、60′组均有肝脏缺血灌注损伤,但PVC－60′组病理损害比45′组重;④PVC组肠粘膜的病理损伤是随门静脉阻断时间延长而加重;⑤PVC组肠粘膜通透性明显升高,肠系膜淋巴结肠道菌属培养阳性率及门静脉血内毒素随阻断时间延长而上升。结论 在本实验条件下正常猪耐受单纯门静脉阻断的安全时限为45min。     

小儿喘咳液对哮喘豚鼠肺超微结构变化的电镜观察

利用透射式电子显微镜观察小儿喘咳液对过敏性哮喘豚鼠肺超微结构变化情况。结果显示:连续雾化吸入卵清蛋白后第1d肺毛细血管壁充血并挤压毛细血管壁,第8d肺毛细血管壁增厚,胶原纤维增生。而用小儿喘咳液连续治疗7d后肺毛细血管壁增厚程度减轻,无胶原纤维增生。证明小儿喘咳液对哮喘有良好的治疗效果。     

Preventive effect of magnesium supplement on noise-induced hearing loss in the guinea pig

The effect of magnesium (Mg) on noise-induced hearing loss was investigated in two groups of adult pigmented guinea pigs maintained either on optimal or suboptimal (physiologically high or low) Mg produced by different diets. The total Mg concentrations of the perilymph (PL), cerebrospinal fluid, blood plasma and red blood cells were measured by atomic absorption spectrometry and were found to differ significantly between the two groups (P < 0.01). One ear of each animal was exposed to either a single shooting impulse at a peak pressure level of 187 dB or two impulse noise series at a rate of 1/s and peak pressure levels of 150 dB (1,000 impulses) and 167 dB (2,280 impulses), respectively. Temporary (TTS) and permanent (PTS) hearing threshold shifts in anesthetized animals were measured 2 h and 1 week after the noise exposure, using auditory brain stem response (ABR) audiometry at a frequency range from 3.75 to 30 kHz. Exposure to the single noise impulse resulted in a mean TTS that was significantly lower in the high Mg group than that in the low Mg group (P < 0.05), although no substantial PTS was observed in either group. In the animals exposed to 150 dB noise, the TTS showed a tendency towards an Mg-related reduction at the higher frequencies. A small difference in PTS was found between the low Mg and high Mg groups, but was not significant. Exposure to the 167-dB noise series caused a considerable TTS, which was significantly lower in the high Mg group at 7.5 and 15 kHz than in the low Mg group (P < 0.05). The mean PTS showed a significant difference between the two Mg groups over the whole frequency range (P < 0.05) and was found to correlate negatively with the total Mg concentrations of both PL and plasma (P < 0.05). Moreover, the high Mg group showed a faster recovery from the hearing threshold shift than the low Mg group. The present findings show that preventive oral Mg supplements can significantly reduce the rate of acoustic trauma caused by high-level impulse noise exposure in the guinea pig. Received: 23 March 1999 / Accepted: 15 April 1999     

后半规管阻塞前后豚鼠前庭及耳蜗功能的动态变化

目的 探讨机械性后半规管阻塞前后豚鼠前庭和耳蜗功能的动态变化。方法 采用２０只豚鼠建立单侧后半规管阻塞的动物模型,观察手术前后眼震电图,听性脑干反应,耳声发射等变化。结果 术后第１天,第３天豚鼠正弦摆动刺激术侧眼震反应,明显减术,术后第５天起双侧眼震恢复正常。术后早期ＡＢＲ阈值一度升高,第５天达高峰,ＡＢＲ阈值平均升高４．５ｄＢ。ＤＰＯＡＥ反应幅度无明显改变。结论 后半规管阻塞能选择性地消除后半规     

氨茶碱雾化吸入对正常及哮喘豚鼠气道粘膜的影响

目的 观察吸入氨茶碱对正常豚鼠气道粘膜的影响及对豚鼠哮喘的预防作用。方法 ３４只豚鼠随机分为６组：对照组、正常动物氨茶碱吸入组、哮喘组、哮喘豚鼠０．５％氨茶碱吸入组、哮喘豚鼠地塞米松吸入组、哮豚鼠０．５％氨茶碱＋地塞米松吸入组,分别行肺泡灌洗液（ＢＡＬＦ）、血清茶碱浓度及病理学检验。结果 正常动物吸入氨茶碱后气道粘膜上皮纤毛不完整,上皮细胞脱落,表面有炎性渗出,粘膜及粘膜下层炎性细胞浸润明显,肺泡