Cannabinoid receptor down-regulation without alteration of the inhibitory effect of CP 55,940 on adenylyl cyclase in the cerebellum of CP 55,940-tolerant mice

The objective of this study was to determine whether the development of tolerance to CP 55,940, a potent cannabinoid agonist, was due to changes in the receptor or second messenger system. ICR mice treated with CP 55,940 (2 mg/kg) twice a day for 6 and one-half days developed a high degree of tolerance to the pharmacological effects of CP 55,940. The ability of CP 55,940 to produce motor hypoactivity, hypothermia and immobility was reduced 163-, 97- and 19-fold, respectively. Evaluation of 3H-CP 55,940 binding to rat brain membranes indicated no difference in receptor affinity between the vehicle- and CP 55,940-treated animals. However, these binding studies revealed a 50% decrease in receptor number in the cerebellum of the CP 55,940-tolerant mice. Although cAMP is generally considered to be the second messenger for cannabinoid receptors, little difference was observed in the inhibitory effects of CP 55,940 on adenylyl cyclase activity in cerebellum between vehicle and drug-treated mice. However, there was an increase in receptor mRNA which suggests a compensation for receptor loss. There are several possible explanations for these results. There may be sufficient spare receptors such that CP 55,940-tolerant mice are capable of producing a maximal effect on the second messenger system. On the other hand, one could conclude that cannabinoid receptor down-regulation does not account for the development of tolerance to all of the effects of CP 55,940 in mice.     

氟罗沙星片剂,胶囊剂的人体药物动力学和相对生物利用度研究

9名男性健康自愿受试者采用三交叉单剂口服国产氛罗沙星片剂、胶囊和进口氟罗沙星片剂各400mg的药代动力学参数比较。血、尿药浓度用HPLC检测．结果表明：体内过程符合一室模型，主要药代动力学参数分别为：AUC：82.30±14．30、81．13±8．45与83．92±14.27h·mg／L；Cmax：4．71±0．83、4．67±0．51与4．86±0．89mg／L；Tmax：1．88±0．44、1．90±0．39与1．92±0．23h；T1／2ke：11．02±0．96、10．93±0．68与10．86±0．82h；V／F（c）：79．08±13．31、78.42±8．70与76．39±12．93L；Cl／F：5．00±0．98、4．98±0．52与4．88±0．73L／h。服药48h的尿中原型药排出率分别为给药量的57．4％，55．9％和60．7％。国产氧罗沙星片剂和胶囊口服后药物动力学参数与进口片剂相仿．其相对生物利用及分别为98.07％与96．68％。     

实验国际学校学生膳食及营养状况的调查

本文对南京实验国际学校369名6～11岁学生进行了膳食及营养状况的分析研究。结果表明：该校学生膳食中除视黄醇、钙及锌（9～11岁组）不足外，其余营养素和热能均超过推荐供应量。蛋白质量足质优。脂肪在一天总热能中比例较高．达到30％左右。该校学生营养过剩发生率达18．4％．提示该校食堂要注意学生膳食的合理调配．防止学生摄入过多脂肪和热能；同时建议增加含钙、锌高的食物供给，以补充其不足。     

广东省梅县乡(镇)卫生院卫生人力资源的现状调查分析

乡(镇)卫生院是农村三级医疗预防保健网的中心环节,是我国农村实现“2000年人人享有卫生保健”的关键。本文通过对广东省梅县乡(镇)一级卫生院卫生人力状况的调查分析,结果表明,目前该县乡镇卫生院的机构稳定,卫技人员占编比例合理,年龄较轻,成为今后农村卫生院发展的优势。但存在着卫生技术人员的总体数量不足,素质较差,各类专业技术人员的构成比例失调和层次分布不合理等问题,同时提出了如何加以改善的对策措施。     

双光气对大鼠肺损伤的研究

研究了双光气染毒后不同时间大鼠支气管肺泡灌洗液（ＢＡＬＦ）成分及肺形态学改变。结果表明，双光气染毒后，ＢＡＬＦ成分的变化程度与肺形态改变密切相关ＢＡＬＦ成分分析可作为动物实验中探测双光气所致肺损伤的有力手段。     

Evidence that [3H]-alpha,beta-methylene ATP may label an endothelial-derived cell line 5'-nucleotidase with high affinity.

1. In membranes prepared from a permanent cell line of endothelial origin (WEC cells), [3H]-alpha, beta-methylene ATP ([3H]-alpha, beta-meATP) labelled high (pKd = 9.5; Bmax = 3.75 pmol mg-1 protein) and low (pKd = 7.2; Bmax = 23.3 pmol mg-1 protein) affinity binding sites. The high affinity [3H]-alpha, beta-meATP binding sites in the WEC cell membranes could be selectively labelled with a low concentration of the radioligand (1 nM). In competition studies performed at a radioligand concentration of 1 nM, 88.6% of the sites possessed high affinity (pIC50 = 8.26) for alpha, beta-meATP. 2. The high affinity [3H]-alpha, beta-meATP binding sites appeared heterogeneous since in competition studies a number of nucleotide analogues (alpha, beta-meADP, ATP, ADP, AMP, GTP, GppNHp, GMP) and adenosine identified two populations of the sites labelled by 1 nM [3H]-alpha, beta-meATP. The proportion of sites with high affinity for these compounds was found to vary between 42 and 69%. 3. Approximately 60-69% of the binding sites labelled with 1 nM [3H]-alpha, beta-meATP possessed high affinity for alpha, beta-meADP (pIC50 = 8.87), AMP (pIC50 = 7.12), GMP (pIC50 = 7.34), UTP (pIC50 = 6.12), GTP (pIC50 = 7.59), GppNHp (pIC50 = 7.35) and adenosine (pIC50 = 5.45).(ABSTRACT TRUNCATED AT 250 WORDS)     

胎盘组织液氨基酸的含量测定及层析鉴别

本文采用层析法进行鉴定,用氨基酸分析仪测氨基酸的含量,为胎盘组织液的质量标准提供可靠依据。本法准确率为99%。     

水飞蓟素对脑缺血性损伤的影响

目的：探讨水飞蓟素对脑缺血性损伤保护作用的机制。方法：采用四血管阻断法造成大鼠全脑缺血模型．观察水飞蓟素对脑匀浆液一氧化氮(NO)和一氧化氮合成酶(NOS)的表达量。结果：水飞蓟素在显降低缺血大鼠脑组织中NO、NOS含量的同时，明显缩小了梗死面积。结论：水飞蓟素能提高机体抗氧化能力，对脑缺血损伤有显的保护作用。     

XIAP与肿瘤化疗耐药关系的研究进展

细胞凋亡程度的降低是肿瘤发生的主要机理，造成肿瘤对化疗药物耐药的主要原因是化疗药物介导的细胞凋亡指数的下降。凋亡抑制蛋白在抑制细胞凋亡中起非常重要的作用,XIAP是IAP家族中抑制细胞凋亡的最主要成员。本文总结了近年来对XIAP抗凋亡机制的研究及其在肿瘤化疗耐药方面的作用。     

Value of serum progesterone for ectopic pregnancy in therapeutic effect monitoring]

OBJECTIVE: To study the value of serum progesterone in selecting the candidate patients with ectopic pregnancy (EP) for methotrexate (MTX) treatment and in monitoring the effect of the treatment. METHODS: Thirty-seven EP patients who were given single-dose intramuscular injection with 50 mg/m2 MTX were divided into success and failure groups according to the effect of the treatment. The serum progesterone concentrations in these patients were measured and compared between the 2 groups, and the receiver-operator curves (ROC) were used to determine the critical serum progesterone levels for assessing the effect of MTX treatment. The time consumed respectively by serum progesterone and beta-human chorionic gonadotrophin (beta-hCG) decreasing to below normal level was also compared. RESULTS: The serum progesterone concentrations of the success group (7.93+/-2.02 ng/ml) were significantly lower than those of the failure group (14.53+/-1.72 ng/ml, P<0.05). The recommended critical level for assessing the effect of MTX treatment for EP patients was 11 ng/ml according to the ROC, and the time for serum progesterone decreasing to below normal level was significantly less than that for beta-hCG. CONCLUSION: Serum progesterone can be used as an index for selecting candidate EP patients for MTX treatment, and also as a good indicator for assessing the therapeutic effect after treatment.