A perspective on measurement of mutations in vivo.

The development of transgenic mouse lines with target genes that are suitable for tissue-specific mutagenesis studies is an important contribution to the field of environmental mutagenesis. These models can accommodate many of the questions relating to metabolism, distribution and relative potency of mutagens as well as providing a more comprehensive system for the identification of mutagens. However, the lesions that the field has learned about methods, development and validation from the use of in vitro systems must be applied to the development and validation of transgenic models.     

天花粉蛋白对荷人肝癌裸小鼠的抑癌作用

目的 探讨天花粉蛋白(trichosanthin,TCS)对荷人肝癌裸小鼠的抑癌作用。方法 采用人肝癌原位移植模型。将24只裸小鼠分为TCSⅠ组、TCSⅡ组、TCSⅢ组和对照组，TCS剂量分别为0．2mg／kg、0．4mg／kg、0．6mg／kg，对照组用生理盐水0．2ml／只腹腔注射，共10次。第21天称瘤重和裸小鼠体重，计算抑癌率。应用免疫组织化学技术，检测瘤组织中Ki67的表达。结果 对照组、TCSⅠ组、TCSⅡ组和TCSⅢ组平均瘤重分别为0．99g、0．81g、0．22g和0．20g。用药组瘤重与对照组相比有显著性差异(P＜0．05)。TCSⅠ组、TCSⅡ组和TCSⅢ组抑癌率分别为18．18％、77．78％、79．80％。对照组、TCSⅠ组、TCSⅡ组和TCSⅢ组平均鼠重增加为2．22g、1．22g、0．28g、一2．37g。用药组与对照组鼠重变化有显著性差异(P＜0．05)。对照组、TCSⅠ组、TCSⅡ组和TCSⅢ组Ki67蛋白阳性表达百分率分别为31．33％、29．92％、10．25％和9．67％。TCSⅠ组Ki67百分率与对照组相比无显著性差异(P＞0．05)。TCSⅡ组和TCSⅢ组Ki67百分率与对照组相比有显著性差异(P＜0．05)。结论 TCS对荷人肝癌裸小鼠的移植瘤有明显的抑癌作用。TCS抑制肿瘤细胞增殖可能是其抑癌的机制之一。     

Accelerated Appearance of Skin Tumors in Hairless Mice by Repeated UV Irradiation with Initial Intense Exposure and Characterization of the Tumors

Skin tumors were produced on the back of hairless mice, HOS (HR/De), by exposure to ultraviolet B light (UVB, 290–320 nm) with 4 different protocols. The first tumors appeared earlier (in 10 weeks in group I and 7 weeks in group III) when initial intense exposure was given, followed by repeated lower-level exposures, than when the mice were exposed to the repeated UV only (in 16 weeks both in group II and group IV). All mice developed skin tumors earlier in the groups given the repeated UV exposures three times a week than in the groups given the exposures twice a week. Most of the skin tumors produced by the UVB exposure were histologically malignant, being transplantable to nude mice, and the cultured cells grown from the tumors were capable of producing tumors when injected into nude mice. The accelerated development of skin tumors by initial intense exposure and short intervals of repeated exposure observed in this study may have implications for humans who expose themselves to intense sunbathing and UV tanning (burning) by fluorescent sun lamps.     

Effects of hemorrhagic shock on endotoxemia and its molecular mechanism

AlthoughtherearegrowingevidencesindicatlugthatonlyweakendotoxemlaexistsintheearlystageafterhemorrhagicshockinhumanbeingsoranirnalsLI-3,antagonistsagainstendotoxinssuchasbacterlcldal/permeablllty--lucreproteinf'j,polymyxinBL4'andlactuloseL',exertsignificantprotectiveeffectsonthevictimsinshock.Thisseemsthatbacterlalendotoxinsplayanimportantroleinthedevelopmentofhemorrhagicshock.However,itremainsunclarifiedwhethertheroleofendotoxinsinshockisrelatedtotheincreaseofanIndividual'ssensitivitytoendot…     

仙人掌提取物对小鼠血糖的影响

目的 :探讨仙人掌水性和酸性提取物对小鼠血糖的影响。方法 :糖尿病小鼠造模成功后分为 5组 :仙人掌酸提物 2个剂量组 (0 .5g·kg-1·d-1和 1.0g·kg-1·d-1) ,水提物 2个剂量组和优降糖组 (2 0 0mg·kg-1·d-1)。正常小鼠灌注等量生理盐水作为正常对照。 6组小鼠均连续给药 2 1d后测血糖。结果 :给药后仙人掌酸提物 2个剂量组血糖均较给药前降低 (P均 <0 .0 5 ) ,2个剂量组间差异无统计学意义 (P >0 .0 5 ) ,但 2组与优降糖组相比 ,P均 <0 .0 5 ;水提物 2个剂量组给药前后血糖无明显变化 (P >0 .0 5 )。结论 :仙人掌酸提物有降血糖作用     

Serotonin 5- HT (2C) receptor knockout mice: autoradiographic analysis of multiple serotonin receptors.

Quantitative receptor autoradiography was used to study possible alterations of the densities of multiple serotonin (5-HT) receptor subtypes and of serotonin transporter in the brain of 5-HT(2C) receptor knockout mice. The radioligands employed were [(3)H]citalopram, [(3)H]WAY100,635, [(3)H]8-OH-DPAT, [(3)H]GR125743, [(3)H]sumatriptan, [(3)H]MDL100,907, [(125)I](+/-)DOI, [(3)H]mesulergine, [(3)H]5-HT, [(3)H]GR113808, and [(3)H]5-CT. As expected, radioligands that label 5-HT(2C) receptors showed a complete absence of labeling in mutant mice choroid plexus and significantly reduced densities in other brain regions expressing 5-HT(2C) receptors. With the rest of the radioligands, no significant alterations in the densities of labeled sites were found in any brain region. In situ hybridization showed no changes in 5-HT(2A) receptor and serotonin transporter mRNA levels, whereas 5-HT(2C) receptor mRNA levels were reduced in certain brain regions. The present results indicate that the mouse serotonergic system does not exhibit compensatory up- or down-regulation of the majority of its components (serotonin transporter and most 5-HT receptor subtypes) in response to the absence of 5-HT(2C) receptors.     

罗格列酮联合胰岛素治疗老年2型糖尿病的临床观察

目的　探讨罗格列酮 (RSG)联合胰岛素 (INS)治疗单用INS血糖控制不佳的老年 2型糖尿病 (DM)患者的临床疗效及安全性。方法　将 68例单用INS疗效不佳的老年 2型DM患者随机分为两组各 3 4例 :对照组继续使用合适剂量的胰岛素治疗 ;治疗组在原剂量胰岛素的基础上加服RSG 4mg/d共 2 0周。观察治疗后 4周及 2 0周患者的空腹血糖 (FBG)、餐后 2h血糖 (PBG)、糖化血红蛋白 (HbA1c)、2 4h尿白蛋白排泄率 (UAER)、每日INS用量变化及药物的不良反应等。结果　治疗组 4周后FBG、PBG下降 (P均 <0 0 5 ) ,治疗 2 0周后以上指标下降更显著 ,并使HbA1C、UAER、舒张压、TG及平均每日INS用量下降 ,差异具显著性 (P均 <0 0 5 ) ;对照组治疗后血糖及HbA1c也有一定下降 ,但INS需要量及低血糖发生率明显增加。结论　RSG确实能有效改善老年 2型DM患者的血糖控制 ,治疗安全有效。该药还能改善代谢综合征的一些异常 ,从而对心血管起到保护作用     

补阳还五汤对小鼠额叶皮质神经元胞体形态影响的定量研究

用体视学方法统计饲补阳还五汤小鼠大脑额叶皮质神经元胞体、细胞核、核仁的８个有关形态参数，结果发现补阳组与对照组比较，在性成熟期胞体体密度Ｖｖ１、细胞核体密度Ｖｖ２、核仁体密度Ｖｖ３均明显减小，细胞核比表面δ３明显增大，在老年期８个参数均无明显变化。结果表明补阳还五汤有一定程度促进生长和恢复大脑功能的作用。     

邻苯二甲酸二乙基己酯对新生小鼠睾丸及Leydig细胞影响的实验研究

目的:探讨邻苯二甲酸二乙基己酯(DEHP)对新生小鼠睾丸及Leyd ig细胞形态结构及功能的影响。方法:DEHP分别以低、中、高3组剂量[100、200、500 mg/(kg.d)]灌胃作用于怀孕12 d到产后3 d(GD12~PND3)的KM母鼠,观察DEHP对新生雄性仔鼠体重、睾丸重量、Leyd ig细胞形态结构和3β-羟基类固醇脱氢酶(3-βHSD)活性、酶反应面积的影响。结果:DEHP作用于母鼠后,其雄性子代幼鼠体重和睾丸重量减轻,睾丸Leyd ig细胞形态、超微结构发生改变;高剂量组Leyd ig细胞数量明显增多;低、中剂量组睾酮合成关键酶3β-HSD酶活性下降,酶反应面积减小,但高剂量组在仔鼠出生后15 d时酶活性降低[(吸光度值(0.154±0.011)vs空白对照组(0.222±0.013),P<0.01],而酶反应面积增大[(6 303.0±745.6)μm2vs空白对照组(5 091.4±214.4)μm2,P<0.01)]。结论:DEHP能影响新生雄性小鼠体重、睾丸重量、Leyd ig细胞的形态结构和3β-HSD活性,具有抗雄激素效应。