MK-801 neurotoxicity in male mice: histologic effects and chronic impairment in spatial learning

Several histological and behavioral experiments were conducted to investigate the neurotoxic effects of MK-801 in male mice. Moderate subcutaneous (s.c.) doses of MK-801 (0.5 and 1.0 mg/kg) induced the formation of intracytoplasmic vacuoles in pyramidal neurons in layers III and IV of the posterior cingulate/retrosplenial (PC/RS) cortex in 50% and 100% of the mice from the two respective treatment groups. Electron microscopic analysis of the vacuoles indicated that mitochondria and endoplasmic reticulum are the cellular organelles most prominently involved in this pathomorphological change. Treating mice with a high systemic dose of MK-801 (10 mg/kg s.c. or intraperitoneal (i.p.)) caused selective, irreversible degeneration of a small number of PC/RS cortical neurons. Compared to saline controls, the acquisition performance of mice treated i.p. with 10 mg/kg MK-801 was chronically impaired on a spatial learning task (modified hole board food search task) when tested at several posttreatment intervals (up to at least 5 months), although the groups did not differ on activity or sensorimotor tests conducted 2 weeks posttreatment. In summary, MK-801 caused histopathological changes in the mouse brain similar to those observed in the rat. Furthermore, high dose MK-801 treatment that killed a small number of mouse PC/RS cortical neurons resulted in a chronic acquisition impairment in spatial learning, an effect not previously demonstrated in any species.     

使用Excel 7.0for Windows95优化换热网络

提出了使用Ｅｘｃｅｌ ７．０ ｆｏｒ Ｗｉｎｄｏｗｓ９５简便和快速优化换热网络的方法。首先由Ｍｏｎｔｅ Ｃａｒｌｏ法确定全局最优点的近似位置,然后由“Ｓｏｌｖｅｒ”求得精确解。全部优化过程由ＶＢＡ语言编写。此法可用于解决许多工程优化问题。     

The development of brain biogenic amines, cyclic nucleotides and hyperactivity in 6-OHDA-treated rat pups

Developmental changes in the behavior and brain biochemistry of rat pups were investigated in rats administered intracisternal injections of 6-hydroxydopamine (6-OHDA) or its vehicle at 5 days of age. Although pups of both groups were equivalent in their activity at 15 days of age, 6-OHDA-induced hyperactivity emerged at 20 and 30 days of age in a between-group design in which rats were only tested at one age. Body weight measurements revealed that 6-OHDA-treated rats were underweight at 15, 25 and 30 days of age. Furthermore, at 20 days of age, total activity was inversely related to body weights in the 6-OHDA-treated pups. Whole-brain levels of dopamine (DA) were decreased at every age by the 6-OHDA treatment, whereas norepinephrine (NE) levels were virtually unaffected by 6-OHDA at these same ages. Total activity was inversely correlated with whole-brain DA levels at 20 and 30 days of age when 6-OHDA-treated pups were hyperactive. Measures of cerebellar and "rest-of-brain" adenosine 3',5'-monophosphate (cyclic AMP) and guanosine 3',5'-monophosphate (cyclic GMP) were not uniformly altered by either the 6-OHDA treatment or by maturation. Results are discussed both in terms of brain biochemistry modulation of hyperactivity and the contribution of decreased body weights induced by 6-OHDA to the production of hyperactivity.     

Biomonitoring lead exposure with δ-aminolevulinate dehydratase (ALA-D) activity ratios

Summary The occupational or environmental exposure of selected populations to lead, either alone or in combination with other metals, was monitored using ratios of the activity of the erythrocytic enzyme -aminolevulinate dehydratase. The results obtained have reaffirmed earlier findings that this test affords several significant advantages over the use of the enzyme's activity value measured at a set pH value and other types of activity ratios to assess lead exposure. Furthermore, the activity ratios' proven sensitivity, reliability, reproducibility, specificity and stability warrant that they be considered as viable alternatives to the more widely accepted diagnostic criteria of lead intoxication namely zinc protoporphyrin and lead levels in blood.     

Effects of heroin,alone or in combination with other drugs,on the locomotor activity in two inbred strains of mice

The locomotor activity of C57B1/6J and DBA/2J mice was studied, under the influences of heroin, amphetamine, strychnine, or ethanol, and of combinations of the opiate with each one of the other drugs. Heroin treatment was followed by the typical running fit in the C57 mice, while the DBA strain was unaffected. Amphetamine enhanced the activity in the C57 strain only. The combination of heroin with amphetamine or ethanol increased the locomotor activity only in the DBA strain, while heroin + strychnine exerted a clear stimulating effect on the activity of the C57 mice. The strychnine + heroin mixture was more toxic than heroin alone when the lethal doses (LD50) were determined in the 2 strains.     

Advanced colorectal cancer in the elderly: results of consecutive trials with 5-fluorouracil-based chemotherapy

To evaluate toxicity and efficacy of chemotherapy in elderly patients (≥65 years of age) with advanced colorectal cancer, data from two consecutive trials conducted between 1984 and 1995 at the National Institute for Cancer Research were analysed comparing the results of treatment in those 65 years of age or older and in those younger than 65 years. Of 215 patients recruited, 82 elderly patients (median age 70 years, median performance status 1) received one of the following regimens based on 5-fluorouracil (5-FU): (1) weekly 5-FU 600 mg/m² i.v. bolus (30 patients); (2) weekly 5-FU 600 mg/m² bolus plus leucovorin (LV) 500 mg/m² 2-h i.v. infusion (28 patients); (3) Weekly 5-FU 2600 mg/m² 24-h continuous i.v. infusion plus LV 100 mg 4-h i.v. infusion and 50 mg orally every 4 h for five doses (24 patients). Overall, 1071 chemotherapy cycles were administered with a median number of 12 courses per patient. The main side effects were diarrhoea, observed in 38% of patients, stomatitis in 24% of patients and hand-foot syndrome in 13% of patients, and haematological toxicity affected only 15% of patients. No patient suffered grade IV toxicity. In three patients chemotherapy was discontinued because of toxicity (two patients suffered grade III diarrhoea, one patient grade III hand-foot syndrome). No significant difference in toxicity was evident between patients older than or younger than 65 years. Analysis of median dose intensity demonstrated no difference between the two groups. Overall objective response was observed in 18% (95% confidence limits 11–29) of elderly patients (15/82) in comparison with 23% (95% CL 17–32) of patients <65 years of age (31/133 pts). In conclusion, chemotherapy in elderly patients with advanced colorectal cancer is a safe and effective treatment with acceptable toxicity and comparable objective response rates. Received: 6 January 1998 / Accepted: 27 February 1998     

异丙酚和氯胺酮麻醉在头面部肿瘤手术中的比较

目的研究异丙酚和氯胺酮麻醉在头面部手术中对血流动力学的影响和术后清醒度的比较。方法５０例病人，ＡＳＡ分级为Ⅰ－Ⅱ，随机分为两组，异丙酚麻醉组（Ｄ），氯胺酮麻醉组（Ｋ）。Ｄ组用异丙酚２．５ｍｇ．ｋｇ－１诱导，用Ｇｒａｅｓｂｙ－３４０泵注异丙酚４．５ｍｇ·ｋｇ－１·ｈ－１维持麻醉；ｋ组用氯胺酮２．０ｍｇ／ｋｇ－１诱导，静脉点滴氯胺酮３ｍｇ·ｋｇ－１·ｈ－１维持麻醉。观察麻醉前（Ｔ０）、注药后（Ｔ１）、插管后（Ｔ２）、手术时（Ｔ３）、拔管前（Ｔ４）５个时点的ＨＲ、ＢＰ的变化，同时观察术后病人清醒的情况，并比较组内的变化和组间的变化。结果两组均对血流动力学有影响，Ｋ组在注药后、插管后、拔管前血压明显升高、心率加快；而Ｄ组在相对时点的ＨＲ、ＢＰ变化比Ｋ组较轻。同时，Ｄ组术后比Ｋ组清醒明显快。结论异丙酚静脉麻醉在头面部肿瘤手术中比氯安酮麻醉更为安全。     

中药蒲黄的化学与药理活性

对近年来国内外有关蒲黄的化学和药理活性研究概况进行了综述，研究发现蒲黄具有多种药理作用，可以改善微循环，提高体内ｃＡＭＰ水平，防治冠心病、高脂血症和心肌梗塞等，且毒副作用少，使用安全，黄酮类化合物为其主要有效成分。指出对中药蒲黄的资源开发和利用研究应进一步深入，同时也应进行扩大资源的研究。     

A comparison of anaesthesia using remifentanil combined with either isoflurane, enflurane or propofol in patients undergoing gynaecological laparoscopy, varicose vein or arthroscopic surgery

BACKGROUND: Anaesthesia comprising remifentanil plus isoflurane, enflurane or propofol was randomly evaluated in 285, 285 and 284 patients, respectively, undergoing short-procedure surgery. METHODS: Anaesthesia was induced with propofol (0.5 mg x kg(-1) and 10 mg x 10 s(-1)), and a remifentanil bolus (1 microg x kg(-1)) and infusion at 0.5 microg x g(-1) x min(-1). Five minutes after intubation, remifentanil infusion was halved and 0.5 MAC of isoflurane or enflurane, or propofol at 100 microg x kg(-1) x min(-1) were started and titrated for maintenance. RESULTS: Patient demography and anaesthesia duration were similar between the groups. Surgery was performed as daycases (52%) or inpatients (48%). The median times (5-7 min) to extubation and postoperative recovery were similar between the groups. Responses to tracheal intubation (15% vs 8%) and skin incision (13% vs 7%) were significantly greater in the total intravenous anaesthesia (TIVA) group (P<0.05). Fewer patients given remifentanil and isoflurane (21%) or enflurane (19%) experienced > or =1 intraoperative stress response compared to the TIVA group (28%) (P<0.05). Median times to qualification for and actual recovery room discharge were 0.5-0.6 h and 1.1-1.2 h, respectively. The most common remifentanil-related symptoms were muscle rigidity (6-7%) at induction, hypotension (3-5%) and bradycardia (1-4%) intraoperatively and, shivering (6-7%), nausea and vomiting postoperatively. Nausea (7%) and vomiting (3%) were significantly lower with TIVA compared with inhaled anaesthetic groups (14-15% and 6-8%, respectively; P<0.05). CONCLUSION: Anaesthesia combining remifentanil with volatile hypnotics or TIVA with propofol was effective and well tolerated. Times of extubation, postanaesthesia recovery and recovery room discharge were rapid, consistent and similar for all three regimens.     

北京市小学生与肥胖相关知识、态度、行为的现况调查

目的　了解北京市小学生的营养状况及其膳食与运动相关知识、态度、行为的现状。方法　采用整群抽样法抽取北京市 4所小学三、四年级全体学生 ,进行问卷调查。结果　北京市小学生瘦长型营养不良率1 3 0 3 % ,肥胖型营养不良率 3 2 0 4%。膳食与运动相关知识掌握较好的学生占 0 73 % ,正确态度持有率 5 6 75 % ,良好行为形成率 1 1 2 7%。知信行均为女生好于男生。知信行间存在一定的关联。结论　健康教育可传授正确的膳食与运动知识给学生 ,转变他们的错误态度 ,从而改变他们的不良行为习惯 ,以促进学生营养状况的改善。