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71.
Frank de Vocht Berna van-Wendel-de-Joode Hans Engels Hans Kromhout 《Magnetic resonance in medicine》2003,50(4):670-674
The interactive use of magnetic resonance imaging (MRI) techniques is increasing in operating theaters. A study was performed on 17 male company volunteers to assess the neurobehavioral effects of exposure to magnetic fields from a 1.5 Tesla MRI system. The subjects' neurobehavioral performances on a neurobehavioral test battery were compared in four 1-hr sessions with and without exposure to magnetic fields, and with and without additional movements. Adverse effects were found for hand coordination (-4%, P < 0.05; Pursuit Aiming II) and near visual contrast sensitivity (-16% and -15%, P < 0.10; Vistech 6000). The results from the remaining tests were inconclusive due to a strong learning effect. No additional effect from gradient fields was detected. The results indicate that working near a 1.5 Tesla MRI system may lead to neurobehavioral effects. Further research is recommended, especially in members of operating teams using interactive MRI systems. 相似文献
72.
目的探讨电离辐射诱发的基因组不稳定性效应。方法采用^60Co γ射线照射人正常肝细胞,检测克隆形成率和微核发生率,利用单细胞凝胶电泳(SCGE)技术检测DNA损伤情况。照射2、4、6、8和10Gy后传代培养,在40代后各剂量组再次统一照射2Gy,进行辐射损伤的检测。结果首次照射后,克隆形成率随受照剂量的增大而降低。存活细胞经二次照射后,SCGE结果和微核发生率结果表明,首次照射剂量与子代二次照射后的损伤程度存在剂量效应关系。结论γ射线不仅在肝细胞中产生直接的生物效应,而且还可以诱发产生可遗传的基因组不稳定性,使子代细胞中的突变频率增加,表现出滞后的遗传改变。二次事件的放大作用是研究基因组不稳定性的一种较好方法。 相似文献
73.
F. V. Costa C. Borghi A. Mussi E. Ambrosioni 《European journal of clinical pharmacology》1986,30(2):145-150
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. 相似文献
74.
D. E. Uehlinger P. Weidmann M. P. Gnaedinger 《European journal of clinical pharmacology》1989,36(2):119-125
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. 相似文献
75.
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. 相似文献
76.
高强度聚焦超声及其医学应用 总被引:1,自引:0,他引:1
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。 相似文献
77.
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。 相似文献
78.
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。 相似文献
79.
Neil M. Rofsky Donald J. Pizzarello Jeffrey C. Weinreb Michael M. Ambrosino Carl Rosenberg 《Journal of magnetic resonance imaging : JMRI》1994,4(6):805-807
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. 相似文献
80.
Persisting cough developed in three children treated with converting enzyme inhibitors. The symptoms disappeared within 3–7 days after withdrawing medication. These observations in children complement previous reports in adults and indicate that cough may be induced by treatment with these agents. 相似文献