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.     

蜂王浆冻干粉对小鼠肿瘤的抑制作用

目的研究蜂王浆冻干粉对小鼠肿瘤的抑制作用.方法按每公斤体重0g、0.25g、0.50g、0.75g设对照及低、中、高3个剂量组,经口给予蜂王浆冻干粉30d后,接种小鼠肉瘤180(S180)和艾氏癌腹水型(EAC)两个瘤种.结果在两次重复的小鼠S180和EAC抑瘤试验中发现中剂量组瘤重明显低于阴性对照组(P<0.05),抑制率可达34%;中剂量组荷瘤小鼠平均生存时间均明显高于对照组(P<0.05).结论蜂王浆冻干粉具有抑制肿瘤的作用.     

高渗盐液和抗休克裤合并应用对大鼠早期休克的影响

采用高渗盐液，抗休克裤及两者联用纠正大鼠早期失血性休克。结果显示，单独使用ＡＳＴ，仅见动脉血压短时间回升，而单用ＨＴＳ，血压则明显回升。若先用ＡＳＴ，再注入ＨＴＳ，也能取得明显效果。失血休克大鼠血浆纤维连接蛋白水平显著降低，各组之间均无差异血浆脂质过氧化物－丙二醛的含量明显增加，且在ＨＴＳ组，ＨＴＳ＋ＡＳＴ组与ＮＳ对照组之间有显著差异。     

表小檗碱对α受体的作用

表小檗碱(epiberberine,EB)是从湖北产黄连(Coptis chinensis Franch)中提取的一种生物碱,属苯喹嗪类原小檗碱,对其药理作用的研究资料甚少,未见其对α肾上腺素体作用的报道。资料表明,许多原小檗碱类化合物有α受体阻滞作用,为从该类化合物中选择     

Validation of impedance cardiography measurements of cardiac output during limited exercise in heart transplant recipients

Abstract. Twenty-one patients were studied at rest and during exercise after heart transplantation to compare cardiac output measured by thermodilution and impedance cardiography. Exercise was performed on a bicycle ergometer over a limited range of work load (25 and 50 watt) whilst metabolic gas exchange was recorded. One patient was studied at rest whilst his circulation was maintained by a Jarvik-7 artificial heart. The values of cardiac output measured by impedance cardiography corresponded closely with the flow rate from the artificial heart. There was also close agreement between the impedance and thermodilution measurements of cardiac output at rest and during exercise. Both measurements followed the changes in heart rate and oxygen consumption. Both thermodilution and impedance cardiography methods elicited good reproducibility of cardiac output measurements at rest and during exercise. These observations suggest that the noninvasive and continuous record of cardiac output obtained by impedance cardiography can be used for the postoperative monitoring of heart transplant recipients.     

大鼠肝细胞Ⅰ，Ⅲ型前胶原基因表达及PDGF的影响

目的观察大鼠肝细胞Ⅰ，Ⅲ型前胶原基因的表达及ＰＤＧＦ对其表达的影响．方法应用原位杂交技术检测分离培养的ＳＤ大鼠肝细胞（ｎ＝３０）内Ⅰ，Ⅲ型前胶原基因的表达．同时观察１０μｇ／Ｌ（ｎ＝３０）和３０μｇ／Ｌ（ｎ＝３０）ＰＤＧＦ促进前胶原基因表达的作用．测定基因表达颗粒总面积占细胞总面积的百分比，并作比较分析．结果无论正常肝细胞或是在两种浓度的ＰＤＧＦ存在时，肝细胞内均可见到Ⅰ，Ⅲ型前胶原基因的表达．正常肝细胞Ⅰ，Ⅲ型前胶原基因表达面积的百分比（％）为７７±１９和７５±２１；加１０μｇ／ＬＰＤＧＦ后为１１５±１９和１１２±１０，而加３０μｇ／Ｌ后为１５２±３４及１８１±２８，且在后者中表达明显增强（Ｐ＜００５及Ｐ＜００１）．结论ＰＤＧＦ在转录水平上促进肝细胞胶原的合成．     

医技人员血源性疾病感染情况调查

医务人员的医院内感染逐渐被人们所关注，其中血源性疾病的感染更应引起大家的重视。为了了解医务人员中医师、检验人员的医院感染发生情况，笔者对某中心医院的医师和检验人员的2002年度体检结果进行了统计分析，现报告如下。     

显微内窥镜下治疗腰椎间盘突出症和腰椎管狭窄症

目的探讨显微内窥镜(MED)治疗腰椎间盘突出症和腰椎管狭窄症的临床效果。方法MED下切除增生内聚的关节突、肥厚的黄韧带及突出的椎间盘，彻底解除对硬膜、神经根的压迫。结果随访324例，按中华骨科学脊柱学组腰背痛手术评定标准，优297例，良14例，差13例，疗效优良率达96．0％，结论MED损伤小、恢复快、疗效好。     

EVALUATION OF IMMUNOHISTOCHEMICAL DIAGNOSIS OF RHABDOMYOSARCOMA

Objective To evaluate the sensitivity and specificity of regularly used immunohistochemical markers, including Vimentin (Vim), Desmin (Des), Myoglobin (MG), Myosin (MS), Smooth-muscle actin (SMA) and Sarcomeric actin ( Sr-A ) , in the diagnosis of rhabdomyosarcoma (RMS). Methods After resection, 24 RMSs and other childhood tumor specimens were fixed in 10% neutral-buffered formalin and embeded in paraffin. The immunohistochemical staining was performed by LSAB procedure. Heat-induced epitope retrieval of Des, MS, Sr-A was processed in order to enhence positive rate and positive strength. Results Vim, MG, MS, Des, Sr-A, SMA were arranged in the order of sensitivity from higher to lower. About specificity, Sr-A, Des, SMA, MG, Vim standed in a sequence from higher to lower ( the data of MS is insufficient) ; Des, MG, Sr-A possessedhigher experimental efficiency, followed by SMA, Vim in a succession. Conclusion Vim and MG are of the higher sensitivity but lower specificity. On the reverse, Sr-A and Des hoM the better specificity but lower sensitivity. So the combination of multiple antibody reactions shouM be considered to improve the diagnostic ability in poorly differentiated RMS. According to the result of experimental efficiency, we suggest that the combination of Des, MG and Sr-A can make it possible to diagnose the majority of RMS clearly.     

新生儿颅内出血的临床分析

目的 为探讨各种类型新生儿颅内出血的早期诊断方法，明确其临床特点与CT的关系。方法 对176例经CT证实有颅内出血新生儿的临床资料进行回顾性分析。结果 176例患儿中缺氧所致123例(72．6％)，产伤21例(11．9％)，新生儿出血症22例(12．5％)，早产儿10例。患儿有意识障碍者156例(88．6％)，惊厥98例(55．68％)，肌张力改变113例(64．2％)，原始反射减弱或消失104例(59％)，贫血16例。CT示：SAH121例。占68．75％，为NICH最常见类型；SDH17例，IPH13例，IVH5例，混合性出血20例。结论 根据临床表现考虑NICH者应做头颅CT或头颅B超检查。Cr是确诊的最佳手段，能正确显示出血部位、范围、程度及区分各种类型，头颅B超对早产儿、低出生体重儿的IVH、IPH检出率高。