Altered enzyme activities of xenobiotic biotransformation in kidneys after subchronic administration of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) to rats

Activities of the xenobiotic metabolizing enzymes were measured in the liver, kidney, duodenum and lung microsomes and cytosol fractions of Wistar rats after subchronic administration of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), a potent bacterial mutagen in chlorinated drinking water. MX was administered by gavage at the dose level of 30 mg/kg for 18 weeks (low dose), or at the dose level which was raised gradually from 45 mg/kg for 7 weeks via 60 mg/kg for 2 weeks to a clearly toxic dose of 75 mg/kg for 5 weeks (high dose). Microsomal and cytosolic preparations were made and the activities of 7-ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-O-dealkylase (PROD), NADPH-cytochrome-c-reductase, UDP-glucuronosyltransferase (UDPGT) and glutathione-S-transferase (GST) were measured. Kidneys were affected most. A dose-dependent decrease was observed in EROD (90% in males, 80% in females at the high dose) and in PROD (58% in females, at the high dose) in kidneys. An increase was, however, detected in kidney NADPH-cytochrome-c-reductase (66% in females at high dose), UDPGT (89% in males and 97% in females at high dose) and GST activities (56% in males and 50% in females at high dose). MX caused only a few changes in the enzyme activities of the liver. The EROD activity was decreased 25% to 37%, both in the livers of males and females, but the total content of P450s was not altered. Hepatic GST activity was elevated in females in a dose-dependent manner (31% and 44%). GST activity was elevated in duodenum in females (59%) at the high dose. There were no marked changes in the enzyme activities in the lungs. MX was a weak inhibitor of EROD activity both in the liver and kidney microsomes in vitro, decreasing the EROD activity by 53% and 43%, respectively at the concentration of 0.9 mM. The results indicate that MX decreases the activity of phase I metabolism enzymes, but induces phase II conjugation enzyme activities, particularly in kidneys in vivo. It is possible that these changes contribute to metabolism of MX in kidneys and renders them susceptible to MX in the course of repeated exposure.     

Inhibitory effects of chlorpheniramine and astemizolum on contraction of isolated rat and rabbit uteri induced by oxytocin and PGF2α

Summary The contraction of isolated rat and rabbit uteri induced by oxytocin and PGF_2α was markedly inhibited by chlorpheniramine (Chl) and astemizolum (Ast), both of which also decreased the resting tension of uteri, and their spontaneous contraction. The inhibitory effects of both drugs were dose-dependent. At high concentrations, Chl 7.4× 10^-4 mol/L and Ast 10^-4 mol/L could counteract the contraction of the uteri induced by Oxy and PGF_2α, and their spontaneous contraction as well. They decreased the resting tension to the lower level. The mechanism of their non-special relaxed action on uteri could not be completely explained only by their H₁-receptor blocking action. Whether they act by blocking calcium channel or by inhibiting calmodulin (CaM) remains to be further explored.     

The potential of an anaesthesiologist–manned ambulance service in a rural/urban district

The use of anaesthesiologists in prehospital emergency care is controversial. We wanted to assess the impact of an anaesthesiologist and a short time interval from acceptance of a mission to take–off at survival rates in a rural/urban emergency medical service. Prospectively registered data for 991 consecutive patients through a 12–month period were retrospectively evaluated by an independent foreign expert. Of all primary missions, 3.3% were considered probably lifesaving from site of injury to receiving hospital. Of these, the lifesaving result in 50% were dependent on both the qualifications of the anaesthesiologist and a short response time. Survival from hospital admission to discharge was 44%. All patients were discharged to their own homes, able to live a fully functional life. The consistent use of anaesthesiologists compared to less qualified personnel and the maintaining of response times below presently required minima doubles the potential for lives saved in services comparable to the one studied.     

泌尿系感染者病原菌及耐药性分析

目的：了解近年来泌尿系细菌感染致病菌及耐药性，为合理应用抗生素，提供临床根据。方法：对泌尿系感染患者298株病原菌进行药物敏感试验。结果：大肠埃希菌仍是引发泌尿系感染的主要病原菌，占53％，其次是葡萄球菌属，占19．40％，肠杆菌属占10．06％，肠球菌属占4．70％等，各类菌属耐药情况。结论：临床医师必须关注本地病原菌分布及耐药情况，合理应用抗生素，减少耐药性播散。     

自制新荧光剂EPQS的性能测试

作者对自制新荧光剂EPQS进行了性能测试。结果:量子产率为0.21;最大激发波长和荧光波长分别为375nm和484nm,stokes位移109nm;检测生物化合物常用的缓冲溶液对荧光峰位无影响,对荧光强度影响很小;温度的影响也小(18～43℃,FRI61.5～58.1),PH的影响也不大。说明EPQS不仅荧光参数好,而且稳定性也好。适合在较广泛的环境条件下使用。     

Characteristics of children and their families at entry into foster care

This study provides an overview of children, their families, and their circumstances at the time that the child entered foster care in Israel. Data regarding a representative sample of 800 children were collected as part of the ongoing operation of a clinical information system set up for Israel's foster care service in 1988. Implications of our findings for interventions are discussed.     

老年大鼠学习行为与海马长时程突触增强和神经元核仁组织者的关系

主动回避条件反应率>80％的老年大鼠为学习好组,<30％的为学习差组。学习好组在高频短串刺激后颗粒细胞层出现海马长时程突触增强(LTP)效应:颗粒细胞核内Ag-NOR面积/胞核面积比值平均为0.154±0.0043;单个胞核内Ag-NOR平均为3.051±0.2212个,学习差组高频短串刺激引起颗粒细胞层群峰电位长时程抑制;颗粒细胞核内Ag-NOR面积/胞核面积比值平均为0.077±0.0023;单个胞核内Ag-NOR平均为1.839±0.1421个,2组间3指标均有显著差异,表明年老大鼠学习能力与LTP效应有关,学习差的老年大鼠海马齿状回颗粒细胞rDNA的转录活性较学习好的明显降低。     

亚胺培南/西司他丁与头孢他啶治疗中、重度细菌感染疗效费用分析比较研究

对我院４５例确诊为中、重度细菌感染住院患者进行了亚胺培南／西司他丁与头孢他啶疗效费用分析比较研究。结果表明：２组病例有效率、死亡率无显著性差异；头孢他啶组较亚胺培南／西司他丁组疗程明显延长。亚胺培南／西司他丁每日所需费用明显高于头孢他啶；治疗结束时，前者全部费用并未超过后者；全部住院费用无明显差异。作者认为：决定２种药物全部费用的因素，除与药物单价和每日费用有关，还与药物疗程密切相关。选用药物抗菌作用越强，用药时间即相应缩短，住院时间必然缩短；最终患者住院费用降低