REPERFUSION FOLLOWING MYOCARDIAL ISCHAEMIA ENHANCES INOSITOL PHOSPHATE RELEASE IN THE ISOLATED PERFUSED RAT HEART

1. Global myocariial ischaemia (MI) for periods greater tan 5 min caused an inhibition of phosphatidylinositol specific phospholipase C (PtdIns-PLC) activity. 2. Two min reperfusion following a 20 min MI period, a time point associated with reperfusion-induced arrhythmias, resulted in an activation of PtdIns-PLC activity, dependent on endogenous noradrenaline and mediated via al-adrenoceptors. 3. This 2 min reperfusion response, in contrast to healthy myocardium, resulted in: (i) enhanced PtdIns-PLC activity; (ii) increased sensitivity to endogenous noradrenaline; (iii) rapid increases in inositol(1,4,5)trisphosphate (Ins(1,4,5)P3); and (iv) PLC hydrolysis primarily of PtdIns(4,5)P₂, such that the majority of InsP isomers derive from Ins(1,4,5)P₃. 4. Together, these data suggest a functional role for Ins(1,4,5)P3 under postischaemic reperfusion conditions, and provide a possible link between al-adrenoceptor stimulation of the PtdIns turnover pathway and reperfusion injury.     

THE INTERACTION BETWEEN ENALAPRILAT AND SELECTED α-ADRENOCEPTOR ANTAGONISTS IN ISOLATED RAT TAIL ARTERIES

1. Isolated perfused rat tail artery preparations were used to investigate the effects of the angiotensin converting enzyme inhibitor enalaprilat on the actions of a series of α-adrenoceptor antagonists. The agonist used was phenylephrine. 2. Enalaprilat (1 μmol/L) potentiated the competitive α₁-adrenoceptor antagonist actions of phentolamine (10–100 nmol/L) and yohimbine (0.3–3.0 μmol/L) as well as the non-competitive antagonist action of phenoxybenzamine (50–100 pmol/L). 3. The competitive α₁-adrenoceptor antagonist action of prazosin (1–10 nmol/L) was not affected by enalaprilat. 4. For the competitive α₁-adrenoceptor antagonists, including prazosin, there appeared to be an inverse relationship between antagonist potency and the extent of potentiation by enalaprilat. 5. The results support the hypothesis and angiotensin II modulates vascular smooth muscle α₁-adrenoceptor function.     

82例双胎妊娠及其围产儿分析

自１９８８年１月～１９９３年１２月我院共分娩１０１２４例，双胎８２例。结果表明：双胎组早产，妊高征、贫血、胎膜早破、产后出血和围产儿死亡率明显高于单胎组，为此提出：①有双胎家族史、由药物诱导排卵的孕妇、孕吐严重、先兆流产和子宫大于停经月份者应作Ｂ超检查，有助于双胎的早期诊断。②妊娠３２周以后，双胎孕妇应连续卧床休息，注意营养，治疗合并症，对减少早产、增加新生儿体重和降低围产儿死亡率有重要意义。     

CHANGES IN PREJUNCTIONAL POTENCY OF B-HT 933 DURING AGING IN THE RAT VAS DEFERENS

1. Age-related changes in prejunctional alpha 2-adrenoceptors were examined in the rat vas deferens using pharmacological techniques. 2. B-HT 933 (1 x 10(-8) - 1 x 10(-6) mol/L) caused a concentration-dependent inhibition of isometric contractions (tetrodotoxin-sensitive) induced by stimulation with single field-stimulus pulses, in both the epididymal and prostatic regions of rat vas deferens. The concentration-response curve to B-HT 933 was shifted to the right with age in the prostatic regions of the vas deferens. 3. In high concentrations (10(-6) - 3 x 10(-4) mol/L), B-HT 933 caused concentration-dependent enhancement of the contractile response to stimulation and evoked spontaneous contractile activity. No significant difference in this postjunctional activity occurred with age in either the prostatic or epididymal regions of the vas deferens. 4. Schild analysis revealed no significant differences in pA2 values for the antagonisms of the prejunctional inhibitory effect of B-HT 933 by rauwolscine in either the prostatic or epididymal regions of vas deferens between young and old rats. 5. These results could be interpreted as a decrease in alpha 2-adrenoceptor number with age. The more marked decrease in the prejunctional inhibitor potency of B-HT 933 in prostatic regions of vas deferens with aging may be due to a smaller receptor reserve in this region of the vas deferens.     

Study of nerve regeneration in centrocentral anastomosis

Summary Nerve regeneration was studied in a model of centrocentral anastomosis (CCA) performed on the sciatic nerve of the rat. Experimental CCA was made by suturing the proximal end of the peroneal branch on the proximal end of the sural branch, placing between them a peroneal nerve graft (Group I, 20 rats) or a silicone chamber (Group II, 12 rats). Nerve grafts had a length of 5mm and silicone chambers 7 mm. In six silicone chambers an 1 mm nerve graft was placed in the centre of the tube. In group I animals anterograde degeneration was studied by cutting the graft 60 days after surgery. In group II, nerve regeneration was studied 2, 4 and 8 weeks after surgery. Results indicate that in CCA: 1) regenerated axons coming from one nerve end grow into the graft but do not cross the contralateral suture line; 2) regeneration is poorer in silicone chambers than in nerve grafts; and, 3) in silicone chambers regeneration is related to time. The reduction in the regenerative capability in CCA seems to be related to the alteration of nerve sprouts aiming for the peripheral targets.     

Inhibition of rat heart allograft rejection by a PUVA treatment of the graft recipient

Treatment of rat heart grafts with PUVA, the combination of the photosensitizer 8-methoxypsoralen and longwave ultraviolet light, leads to a prolonged transplant survival in allogeneic recipients. A PUVA treatment of the recipient rats, performed for 7 consecutive days after transplantation, prolonged graft survival even more effectively. This may be due to the systemic immunomodulatory effects of PUVA in the recipient. One of the mediators is urocanic acid, which is transformed by ultraviolet light in the skin from its trans- to the cis-isomer, which, in turn, acts as a mediator on the immune system. An injection of cisurocanic acid into graft recipients for 7 consecutive days after transplantation resulted in prolonged graft survival; in 40% of the rats, permanent graft acceptance was observed. The significance of these results for clinical organ transplantation is discussed.     

Investigation of aneuploidy induction in mouse oocytes following exposure to vinblastine-sulfate,pyrimethamine, diethylstilbestrol diphosphate,or chloral hydrate

The various causative and mechanistic phenomena associated with aneuploidy induction require considerable investigation to better understand the etiology of chromosome missegregation. We investigated the potential of vinblastine sulfate, pyrimethamine, diethylstilbestrol diphosphate, and chloral hydrate to induce numerical and structural chromosome changes in female mouse germ cells. Superovulated ICR mice were administered the compounds either by intraperitoneal injection or oral gavage, and oocytes were collected and processed for cytogenetic analysis 17 hr later. Vinblastine sulfate, administered i.p., induced a significant increase in the frequency of ovulated Ml oocytes and of hyperploid Mll oocytes compared to controls, but did not increase the frequency of structural aberrations. Pyrimethamine, diethylstilbestrol diphosphate, and chloral hydrate did not increase the frequency of numerical or structural chromosome changes in female mouse germ cells. © 1993 Wiley-Liss, Inc.     

大鼠腹腔肥大细胞肿瘤坏死因子合成与释放的研究

应用免疫细胞化学技术及酶联免疫吸附试验（ELISA）对大鼠腹腔肥大细胞合成和释放肿瘤坏死因子（TNF）的状况进行了观测。结果:新鲜分离纯化的大鼠腹腔肥大细胞胞浆呈TNF蛋白阳性。单纯肥大细胞培养早期（2～4 h）,上清液中未能检测到TNF,随着培养时间延长,上清液中TNF含量增多;盐酸吗啡与肥大细胞共同培养2h时,上清液中出现可测TNF。四甲基偶氮唑盐（MTT）比色分析试验表明,肥大细胞培养上清液具体有TNF的抗肿瘤活性中。提示:大鼠腹腔肥大细胞能合成和释放TNF,盐酸吗啡能促进肥大细胞释放TNF。     

Women's knowledge, practises, and intentions regarding correct pelvic floor exercises.

AIM: Although research has demonstrated the efficacy of pelvic floor exercises (PFXs) for the prevention and treatment of female urinary incontinence (FUI), adherence to PFX regimens is commonly poor. There is some evidence that this finding is in part due to a lack of knowledge about how to perform PFXs correctly and misconceptions about the required frequency and duration of PFX regimens. METHODS: By using a sample of 720 postpartum women, this study investigates women's PFX regimens both before and during pregnancy and postpartum. RESULTS: Findings demonstrated that most women were aware of the required frequency for PFXs (at least every second day): just over half had done them this often during pregnancy and 91% intended to do so postpartum. However, few had done them at this level before pregnancy and less than half knew that PFXs should be carried out indefinitely throughout the lifetime. Moreover, only two thirds were confident that they were doing PFXs correctly. CONCLUSION: The findings suggest that, despite good knowledge of the required frequency of PFXs, few women practise them regularly over their lifetime, many apparently perceiving PFXs as relevant only to the childbirth years. Implications for health professionals in addressing these gaps in women's knowledge and practises are discussed.