ANTIHYPERTENSIVE EFFECTS OF MESULERGINE: FURTHER EVIDENCE FOR A PERIPHERAL SITE OF ACTION OF DOPAMINE AGONISTS

The cardiovascular effects of mesulergine were studied in anesthetized dogs. Intravenous (IV) administration (0.3 mg/kg) significantly decreased blood pressure in neurogenic hypertensive dogs without any change in heart rate. This effect was completely antagonized by IV administration of domperidone (0.5 mg/kg). Intracisternal administration of mesulergine (0.03, 0.3 and 3 mg/kg) did not produce any change in blood pressure. However, with the highest dose we observed a significant rise in heart rate during the first 2 min (which was probably nonspecific). These results suggest that mesulergine lowers blood pressure in sinoaortic-denervated dogs by means of a peripheral mechanism probably involving DA2 receptors. The findings confirm the potential interest of dopamine-receptor agonists as future antihypertensive agents.     

Dual blockade of the renin-angiotensin system in type 1 patients with diabetic nephropathy.

BACKGROUND: Albuminuria and hypertension are predictors of poor renal and cardiovascular outcome in patients with diabetes. Approximately 30% of type 1 patients with diabetic nephropathy (DN) have albuminuria >1 g/day, and blood pressure >135 and/or >85 mmHg despite antihypertensive therapy with recommended doses of ACE inhibitor (ACEI) and diuretics. We tested the effect of dual blockade of the renin-angiotensin system (RAS) in these patients. METHODS: We performed a randomised double blind crossover trial with 2 months treatment with Irbesartan 300 mg o.d. and placebo added on top of previous antihypertensive treatment. We included 21 type 1 patients with DN responding insufficiently to ACEI and diuretics, as defined above. At the end of each treatment period, albuminuria, 24-h blood pressure and glomerular filtration rate (GFR) were measured. RESULTS: Addition of 300 mg Irbesartan to the patients' usual antihypertensive therapy induced a mean reduction in albuminuria of 37% (95% CI 20-49, P<0.001); from 1574 mg/24 h (95% CI 1162-2132) to 996 mg/24 h (95% CI 699-1419), a reduction in 24-h blood pressure of 8 mmHg systolic (95% CI -2 to 18) and 5 mmHg diastolic (95% CI 1-9) (P=0.11 and 0.01, respectively) (from placebo, mean (SE) 146 (4)/80 (2) mmHg). GFR remained unchanged. Serum potassium increased (mean 4.3 to 4.6 mmol/l, P=0.02). Intervention to reduce serum potassium was needed in two patients with GFR <35 ml/min/1.73 m(2). Otherwise the dual blockade with Irbesartan was safe and well tolerated. CONCLUSIONS: Dual blockade of the RAS may offer additional renal and cardiovascular protection in type 1 patients with DN responding insufficiently to conventional antihypertensive therapy, including recommended doses of ACEI and diuretics.     

解耦联蛋白在心肌中的表达与心力衰竭

位于心肌线粒体内膜上的解耦联蛋白 (UCPs) ,作为质子通道驱散氧化呼吸时形成的H 梯度 ,使产能转化为产热 ,从而增加呼吸 ,阻止ATP形成 ,并抑制活性氧族的产生 ,最终阻止了心肌细胞的程序性死亡。脂肪酸、寒冷、甲状腺激素、肾上腺素等能调控UCPs的浓度和活性。UCPs在心力衰竭中的作用仍然不清楚 ,有待进一步研究     

右心室不同部位起搏血液动力学改变的研究

目的：根据右心室不同部位起搏时血液动力学改变，研究选择置入右心室双部位起搏器辅助治疗心脏扩大合并充血性心力衰竭(CHF)，观察临床效果及心脏功能；方法：对13例在心内科住院的扩张型心肌病、缺血性心肌病、心动过速性心肌病所致心力衰竭的患者，男9侈4，女4侈4，年龄36岁～75岁(平均58．61岁)，心功能均在Ⅲ级～Ⅳ级(NYHA)，均有置入起搏器的适应证。术中通过Swan—ganz漂浮导管对右心室内不同部位起搏10分钟后测各部位的急性血液动力学改变，然后置入右心室双部位起搏器(右室流出道应用主动固定电极)。术后应用心电图、超声心动图观察右心室双部位起搏的血液动力学效果；结果：全组13例患者术中检查及置入右心室双部位起搏器均获成功。测得右心室流出道起搏(RV—OT)和右室心尖部(RVA) 右室流出道(RVOT)起搏时各参数均较单纯右室心尖部(RVA)为好。置入心脏起搏器后观察射血分数从0．31提高至0．39，左室充盈时间延长，二尖瓣返流量减少，心脏缩小，心脏功能平均提高Ⅱ级。其中一例心功能由Ⅳ级提高至I级～Ⅱ级；结论：初步血液动力学观察提示，右心室双部位起搏能改善充血性心力衰竭患者的心功能。     

Milk consumption and prevalence of coronary heart disease in men and women from the Scottish Heart Health Study

This report uses cross-sectional results from the Scottish Heart Health Study to investigate whether milk consumption has an independent effect on the prevalence of coronary heart disease. Milk consumption was assessed by questionnaire in men and women aged 40–59 years (n = 10359) who participated in a survey of risk factors for coronary heart disease between 1984 and 1986. Odds ratios for coronary heart disease were calculated according to volume and type of milk consumed for subjects with and without symptoms of coronary heart disease. Statistical adjustment was made for the classicial risk factors.
A higher percentage of men and women with diagnosed coronary heart disease (CHD) usually consume low-fat milk, compared with asymptomatic controls. Odds ratios for having undiagnosed heart disease did not differ significantly with volume or type of milk. However, the odds ratios for having diagnosed heart disease were lower in the moderate (0.5–1 pint/d) milk consumption group. Patterns of milk consumption in patients diagnosed as having CHD are likely to be confounded by dietary changes post-diagnosis. Milk consumption appears to have little independent effect on the prevalence of coronary heart disease in this Scottish population.     

Calculation of Hydrolytic Rate Constants of Poly(ortho ester)s from Molecular Weights Determined by Gel Permeation Chromatography

Purpose. To obtained rate constants from weight-averaged (M_w) or z-averaged (M_z) molecular weights for polymers of Schule-Flory distribution and undergoing random scission. These constants were compared with those obtained by parallel ¹HNMR studies. Methods. The hydrolysis of two poly(ortho ester)s were followed by ¹HNMR and gel permeation chromatography (GPC). Results. Equations to convert number-averaged (M_n), M_w and M_z into fraction of backbone remaining (f_c) were derived. First-order hydrolytic rate constants of two poly(ortho ester)s; DETOSU-HD and DETOSU-CDM were calculated using these relationships. The rate constants calculated from ¹HNMR, M_z and M_w were 0.215, 0.218 and 0.182 hr^–1, respectively, for DETOSU-CDM and 0.152, 0.086 and 0.038 hr^–l for DETOSU-HD. The large discrepancy in the rates determined by ¹HNMR and GPC in the latter case was attributed to that the detector response (refractive index) of the monomers was lower than that of the high molecular weight polymer. The difference is small in the case of DETOSU-CDM, and the rates calculated from GPC data were comparable or nearly identical to that obtained from ¹HNMR data. Conclusions. Although GPC can yield rapid and valuable kinetic data for the degradation of biodegradable polymers, the system, however, must be carefully calibrated to account for the variations in Mark-Houwink coefficients and in the response of the mass detector between the high and low MW polymers.     

先天性心脏病患儿肺动脉,上腔静脉血一氧化氮含量检测及意义

目的:探讨一氧化氮(NO)与先天性心脏病(CHD)引起的肺动脉高压(PH)发病间的关系。方法:应用NO试剂盒检测了CHD患儿肺动脉及上腔静脉血浆中NO含量。结果;(1)伴PH组肺动脉血浆NO含量明显高于不伴肺动脉高压组(37.58±9.99μmol/L:19.03±15.25μmol/L,P<0.01);(2)在PH组中,肺动脉血浆NO含量明显高于上腔静脉血(P<0.01);而不伴PH组,肺动脉和上腔静脉血浆NO含量无显著性差异(P>0.05)。结论:(1)伴PH的先心患儿肺动脉血浆NO含量升高;(2)NO可能介入了CHD引起的PH发病过程。     

Adenosine protects ultrastrueture of isolated rat lungs against fat emulsion injury

In isolated rat lungs subjected to fat emulsion damage, a model simulating adult respiratory distress syndrome, we have previously reported that adenosine (ADO) reduces pulmonary vascular resistance (PVR) and the fluid filtration rate (FFR). In the present study the aim was to examine morphologically this effect of ADO. Two groups of isolated rat lungs were subjected to the injury. Marked and significant differences were found between the groups; in lungs not given ADO, FFR and airway pressure were higher and, as evaluated by electron microscopy, the endothelial lining was thin and partly disrupted. The epithelial cells of the alveolar walls were also partly disrupted and the alveolar septa were split enclosing interstitial edema. In lungs receiving ADO from the onset of exposure to fat emulsion, FFR was lower and ultrastructure did not differ from non–injured non–treated controls perfused for the same length of time.     

149例围产儿死亡原因分析

目的：探讨围产儿死亡原因及降低围产儿死亡率的措施。方法：对1994年1月－2001年12月在我院住院分娩的149例死亡围产儿的临床资料进行回顾性分析。结果：围产儿死亡率为22．74‰，死胎率为9．77‰，死产率为3．36‰，早期新生儿死亡率为9．62‰，占42．28％。围产儿死亡原因：缺氧占47．65％，早产占21．15％，出生缺陷占12．08％。结论：加强孕期保健、规范系统产前检查及监护、积极预防治疗妊娠并发症、防治早产、实施正确的新生儿窒息复苏方法、建立NICU等是降低围产儿死亡率的重要环节。     

Ten-year stability of cardiovascular responses to laboratory stressors

In this study we examined test-retest stability of cardiovascular stress responses over a decade of the life span. Participants were 55 male college undergraduates. 19 years of age at initial testing, and 29 years of age at follow-up testing Stressors were a foot cold pressor and an aversive reaction time task. Cardiovascular measures included systolic and diastolic blood pressure, heart rate, and preejection period. For cold pressor, the magnitude and pattern of cardiovascular responses remained unchanged at the 10-year follow-up. For the reaction time task, the characteristic cardiovascular response patterns was preserved but with significant attenuation of magnitude. The present findings are consistent with previous observations of temporal stability but over a substantially longer test-retest interval. The long-term stability of stress responses is discussed in the context of stress test methodology, behavioral response demands, and maturation of the physiological systems involved in cardiovascular response expression.