Cadralazine and chlorthalidone as a second-step drug with atenolol in hypertensive patients: Differences in blood pressure control during exercise

Summary The long-term efficacy of a new vasodilator, cadralazine (ISF 2469), and chlorthalidone have been compared in 20 hypertensive patients not adequately controlled by atenolol. After 4 weeks of treatment with atenolol 100 mg once daily, patients whose diastolic blood pressure was >95 mmHg were randomly divided into two groups to receive in addition to atenolol, either cadralazine 15 mg once daily or chlorthalidone 25 mg once daily. Both treatments were administered for 6 months. At the end of treatment with atenolol and after 3 and 6 months of combination therapy, blood pressure and heart rate were measured at rest and during bicycle exercise 24 h after the last dose. Compared to atenolol alone, both cadralazine and chlorthalidone caused a significant and similar reduction in resting blood pressure. Both groups showed an increase in diastolic blood pressure during exercise while receiving atenolol alone. The addition of chlorthalidone did not modify the pressor response to exercise, whereas patients taking cadralazine had a decrease in exercise diastolic blood pressure, which was fully evident after 6 months of therapy. The reduction in exercise diastolic blood pressure induced by cadralazine was proportional to the increase in exercise heart rate, suggesting a fall in peripheral vascular resistance. Chlorthalidone caused a significant increase in serum glucose and uric acid and a decrease in K⁺, whereas no change was observed during cadralazine It is concluded that cadralazine given once a day with atenolol has the same efficacy in controlling blood pressure at rest as the combination of atenolol and chlorthalidone, and in addition it improves the pressor response to dynamic exercise and does not cause unwanted metabolic effects.     

Cardiovascular regulation and lipoprotein profile during administration of co-dergocrine in essential hypertension

Summary Co-dergocrine has recently been demonstrated acutely to lower plasma norepinephrine (NE) and blood pressure (BP) in patients with essential hypertension, and similar results have been obtained during chronic administration of co-dergocrine to healthy men. The present study investigated the effect of 3 weeks of treatment with co-dergocrine 4 mg/day on BP, plasma catecholamines, certain other BP-regulating factors and serum lipoproteins in patients with essential hypertension. Compared to placebo conditions, co-dergocrine decreased supine BP and heart rate by −7% and the upright plasma NE level by −24%. Supine plasma NE also fell (−24%). Total cholesterol and the LDL + VLDL-cholesterol lipoprotein fraction were lowered by −6%. No significant change was observed in plasma renin activity, angiotensin II, aldosterone and epinephrine levels, whole blood and plasma volume, exchangeable sodium, and the cardiovascular responsiveness to NE, angiotensin II and isoproterenol. The findings suggest that in patients with essential hypertension, chronic treatment with co-dergocrine may slightly decrease sympathetic outflow and, at least in the short-term, lower the potentially atherogenic serum LDL + VLDL − cholesterol fraction.     

Disposition of a silicon-containing amide, an inhibitor of acyl-CoA: cholesterol acyltransferase, in dog and rat

The pharmacokinetics of 3-(decyldimethylsilyl)-N-[2-(4-methylphenyl)-1-phenylethyl]propanamide (DMPP), an inhibitor of acyl-CoA:cholesterol acyltransferase, have been studied in the dog and the rat using 14C and 3H dual-labelled drug. In both species, gastrointestinal absorption of DMPP was slow and incomplete, amounting to approximately 20 per cent of the oral dose given in corn oil. In the rat, use of PEG-400, Tween 80, ethanol, and aqueous CMC as vehicles resulted in similar or lower absorption than corn oil. Absorbed DMPP was rapidly and extensively distributed to body tissues. Data from the rat showed highest concentrations of radioactivity in the liver and spleen, while concentrations in the adrenals and lung also markedly exceeded circulating radioactivity levels. In both dog and rat. DMPP was completely metabolized prior to excretion. The routes of biotransformation involved hydrolysis of the amide bond, oxidation of the phenyl ring, and degradation of the decyldimethylsilyl propanoyl moiety. The metabolites of DMPP were excreted slowly, predominantly in the faeces. The elimination half-life of 14C was 105 h in the dog and 83 h in the rat, while that of 3H was approximately 32 h in both species.     

细菌性痢疾季节性高峰变化及其与气温关系的研究

目的 探讨气温对细菌性痢疾发病的影响。方法 应用相关回归统计法和圆形分布法对资料进行研究。结果 菌痢的月平均发病百分构成比与相应年份月平均气温呈正相关(r=0.5099,P<0.01);辖区近10年的平均气温较前10年有所上升,尤其秋冬季与初春月平均气温升高了1℃左右,而菌痢发病高峰时点明显后移(F=11.49,P<0.01),流行高峰期也有后移倾向。结论 气温对菌痢的发病有直接影响,气温升高,菌痢的发病增加,年平均气温升高可导致菌痢的发病高峰时间后移。     

高强度聚焦超声及其医学应用

HIFU技术的研究在国内外已掀起了热潮．到目前为止．HIFU技术已得到广泛的实验和临床支持。本文将对HIFU治疗设备的总体结构做一阐述．并讨论其在医学领域中的应用及发展方向。     

二硫化碳对F_1代出生后发育及对F_2代后遗影响的研究

报道了F_0代SD雌性大鼠妊娠前2周和整个妊娠期间染毒二硫化碳(CS_2)对F_1代出生后发育和对F_2代的后遗影响。结果表明,CS_2可使F_1代出生后生长发育明显减慢。CS_2对F_1代行为发育的影响主要表现为表面翻正反射阳性率降低,旷场试验中排便次数明显增加。CS_2对F_2代具有明显致畸作用,主要为胸骨缺失、枕骨骨化迟缓、囟门增大。但对F_2代胎鼠体重和宫内发育未见异常。综上所述,可以认为,CS_2对F_1代甚至F_2代均可产生明显影响和致畸作用。     

Central cardiovascular and oxygen variables during haemorrhage in the pig

Background: We evaluated the ability of the standards issued by the Danish Society of Anaesthesiologists to reflect a blood loss.
Methods: In 9 pigs bled (0–24 ml kg^-1) and retransfused (to 28 ml kg^-1) during halothane anaesthesia, central cardiovascular, thoracic electrical impedance (TI), oxygen, acid-base and temperature variables were recorded.
Results: With the recommendation for minor surgery (mean arterial pressure (MAP) and heart rate (HR)), the correlation to the blood loss was 0.74 ( P < 0.001) and with that for major surgery (MAP, HR, central venous pressure (CVP) and rectal temperature (Temp_r)) it was 0.79 ( P < 0.001). With the recommendation for extensive surgery (MAP, HR, CVP, pulmonary artery catheter variables and the central-peripheral temperature difference (ΔTemp_r-t)), the correlation was 0.84 ( P < 0.001). Non-invasive monitoring (MAP, HR, ΔTemp_r-t TI and near-infrared spectroscopy of the brain (S_invosO₂)) was only slightly better than basal monitoring (r=0.76, P < 0.001). However, adding arterial base excess (BE), TI and peripheral temperature (Temp_t) to the recommendation for major surgery resulted in a correlation of 0.87 ( P < 0.001), while adding BE and TI to the recommendation for extensive surgery raised correlation to only 0.88 ( P < 0.001).
Conclusion: When the recommendations were followed the correlation to the blood loss ranged from 0.74–0.84. However, with the recording of MAP, HR, CVP, ΔTemp_r-t, BE and TI a correlation of 0.87 was achieved, indicating that a pulmonary artery catheter may not be in need for patients undergoing surgical procedures with expected haemorrhage.     

淋巴细胞亚群微核表达的辐射效应研究

简述了淋巴细胞亚群微核检测方法、淋巴细胞亚群自发微核率和影响因素，以及关于电脑射效应的研究现状，为微核法用于辐射生物剂的未来发展提供了有益信息。     

清热中药对大鼠下丘脑组织中AVP含量的影响

选用典型的清热中药黄芩、银花、连翘组成清热方,从体温调节中枢神经介质方面来探讨清热类中药的解热作用机制。实验表明影响体温调节中枢解热介质AVP代谢,增加其含量,从而抑制体温调定点上移是清热中药作用机理之一。     

Effect on fetal mouse development of exposure to MR imaging and gadopentetate dimeglumine

Pregnant mice were exposed to one of five regimens at 9.5 days of gestation: no treatment (group 1), intraperitoneal injection of normal saline (group 2), intraperitoneal injection of gadopentetate dimeglumine (group 3), intraperitoneal injection of gadopentetate dimeglumine and magnetic resonance (MR) exposure (group 4), and MR exposure alone (group 5). At 18 days of gestation, the mice were sacrifice and fetuses were removed and examined for the following end points: litter size, number alive or dead, fetal weight, extremity morphology, eye and ear development, and appearance of the head. A total of 739 fetuses were analyzed: group 1 (n = 161), group 2 (n = 149), group 3 (n = 142), group 4 (n = 136), and group 5 (n = 151). The only statistically significant difference was a lower mean fetal weight in the saline-injection group compared with the control group. The results show that MR exposure with and without gadopentetate dimeglumine had no adverse effect on the end points analyzed.