Retrospective estimation methods of pesticide occupational exposure]

The extensively growing use of pesticides in the last decades has led to great improvements in agriculture but also to threats for human health. Studying long term effects to assess individual exposures encounters difficulties in exposure assessment. This article summarizes retrospective methods for assessing occupational exposures to pesticides currently used in epidemiological studies. Questionnaires, environmental and biological monitoring constitute direct assessment of exposure, in an individual approach. But the validity of questionnaires is often poor and the metrology rarely reflects past exposures. Some indirect measures have been used together with job exposure matrices. To establish dose-response relationships is important to quantify the risk, but needs accurate exposure assessment based on quantitative indexes.     

膀胱移行细胞癌微卫星不稳定性及其机制的研究

目的　探讨膀胱移行细胞癌 (BTCC)染色体微卫星不稳定性的表现及与基因突变的关系。方法　采用聚合酶链反应 (PCR)方法检测 4 0例 BTCC患者 5个微卫星位点的改变 ,同时用同样的方法检测癌组织中BAX基因和转化生长因子 (TGF) - β 型受体基因移码突变的情况。结果　至少发生一个微卫星位点改变的阳性率为 82 % (33/ 4 0 ) ,D9S16 2、D16 S4 76、D9S5 4、FGA和干扰素 (IFN) - A1位点改变各自的阳性率分别为 5 8%(2 3/ 4 0 )、 4 2 % (17/ 4 0 )、 38% (15 / 4 0 )、 4 8% (19/ 4 0 )和 5 5 % (2 2 / 4 0 ) ,阳性检出率与良性病变差异有显著性 ,与肿瘤的分期分级无显著相关性。发生微卫星改变的 33例中 ,33% (11/ 33)和 4 2 % (14 / 33)分别可见 TGF- β 型受体基因和 BAX基因的移码突变。结论　检测染色体微卫星的改变是 BTCC早期诊断、监测复发的有效手段 ,染色体微卫星改变可能是 BTCC发生过程中多基因突变的一种表现形式     

软式膀胱尿道镜检查技巧

目的 :提高软式膀胱尿道镜检查的技术水平。方法 :报告软式膀胱尿道镜检查的成功经验及所遇问题。结果 :软式膀胱尿道镜对膀胱、尿道的观察均具有明显的优势 ,可完成活检、插管、取异物等多项操作。结论 :软式膀胱尿道镜检查痛苦小 ,可替代硬式膀胱尿道镜 ,使用广泛 ;熟练掌握软式膀胱尿道镜的操作技巧是检查成功及延长使用寿命的关键     

异丙酚对神经元缺氧损伤的保护及其作用机制

目的　研究异丙酚对离体大鼠海马神经元缺氧损伤的保护作用及其机制。方法　以原代培养的大鼠海马神经元作为研究对象 ,建立缺氧、H2 O2 和谷氨酸损伤模型 ,用MTT法测定神经元存活率。采用激光扫描共聚焦显微镜动态监测缺氧前后 ,单个海马神经元内Ca2 + 浓度和线粒体膜电位 (△Ψm)的变化。用电子自旋共振技术测定异丙酚对羟基自由基和超氧阴离子自由基的清除作用。结果　 6～ 4 8mg·L-1浓度的异丙酚可明显降低神经元缺氧损伤时的细胞死亡率 (P <0 0 1) ,作用程度均呈剂量相关 (r =0 89,P <0 0 5 ) ;2 4～ 4 8mg·L-1浓度的异丙酚可明显降低H2 O2 损伤时的细胞死亡率 (P <0 0 1) ;12～ 4 8mg·L-1浓度的异丙酚可明显降低谷氨酸损伤时的细胞死亡率 (P <0 0 1)。 3～ 4 8mg·L-1异丙酚对缺氧诱发的细胞内钙离子超载有抑制作用(P <0 0 5 ) ;12、4 8mg·L-1异丙酚能减缓缺氧引起的△Ψm降低 (P <0 0 1)。 12、4 8mg·L-1异丙酚对羟基自由基的清除率分别为 17 1%和 2 1 1% ,但对超氧阴离子自由基无清除作用。结论　异丙酚对离体培养的大鼠海马神经元缺氧性损伤具有保护作用 ,其作用机制部分与异丙酚抑制缺氧引起的 [Ca2 + ]i 异常升高、抑制线粒体膜电位的下降和清除羟基自由基有关     

丙泊酚对N-甲基-D-天冬氨酸所致PC12细胞损伤的保护作用

目的　探讨静脉麻醉药丙泊酚 (PPF)脑保护作用的可能机制。方法　乳酸脱氢酶 (LDH)法及MTT比色法判断细胞损伤程度及细胞存活率 ,Fura 2 /AM荧光标记法测定细胞内Ca2 + 浓度 ( [Ca2 + ]i)的变化 ,分光光度法测定细胞一氧化氮合酶 (NOS)活性。结果　N 甲基 D 天冬氨酸 (NMDA) 3 0 0 μmol·L-1处理4h可明显导致PC1 2细胞的损伤 ,表现为LDH释放量明显增加 ,吸光度值A570nm明显降低 ,细胞存活率降低 ,同时 [Ca2 + ]i 和NOS活性则明显增加。PPF6.2 5 ,2 5 ,1 0 0 ,40 0 μmol·L-1与NMDA同时处理PC1 2细胞则使LDH释放量显著降低 ,细胞存活率增加。PPF 1 2 .5和 1 2 5 μmol·L-1可显著降低NMDA诱导的[Ca2 + ]i 水平及NOS活性的提高。结论　PPF对NMDA所致的PC1 2细胞损伤有明显的保护作用 ,其机制可能与其抑制NMDA受体的功能 ,降低 [Ca2 + ]i,减弱Ca2 + 超载 ,并降低NMDA诱导的NOS活性增加有关。提示PPF可能是通过抑制NMDA受体 Ca2 + NOS通路的功能而产生细胞保护效应     

白术对抗体形成细胞的作用研究

目的：观察白术对小鼠抗体形成细胞的作用。方法：用100％浓度白术浸出液定期给小鼠灌胃，然后检测小鼠抗体产生能力．特异玫瑰花环结形成细胞检测(SRFC)、血清IgG检测。结果：用药组以上三项免疫学指标均增高，结论：白术有明显促进抗体形成细胞的作用。     

视黄酸依赖反义cyclin D1对HL-60细胞增殖和分化的影响及其机制

目的 :探讨视黄酸 (retinoicacid ,RA)及其诱导的反义 (anti sense ,AS)cyclinD1对肿瘤细胞的协同抑制增殖与诱导分化效应及其机制。方法 :通过构建的含有视黄酸反应元件 (retinoicacidresponseelement ,RARE)的反义cyclinD1RNA表达载体 pCI neo/RARE3 TK/AscyclinD1,使反义cyclinD1的表达可受RA诱导调控。以脂质体转染HL 60白血病细胞后 ,运用生长曲线、MTT比色法和流式细胞仪分析检测细胞增殖功能 ,NBT还原实验和透射电镜观测细胞分化状况 ,western blot检测p16基因蛋白表达水平。结果 :反义cy clinD1转染和未转染的HL 60细胞经RA处理后 ,生长减慢 ,细胞被阻滞在G0 /G1期 ,分化能力明显增强 ,p16基因蛋白表达增加 ,其中 ,以反义cyclinD1转染细胞经RA处理后变化更为明显。结论 :RA及其诱导的反义cyclinD1可协同抑制HL 60细胞增殖和诱导细胞分化成熟 ,上调p16基因表达可能是其分子机制之一。     

Uteroglobin and transglutaminase modulate human sperm functions

During the process of capacitation, spermatozoa undergo significant changes in membrane composition, including removal of decapacitating factors (DFs), which are present in seminal plasma, that lead to increased sensitivity to physiological stimuli of the acrosome reaction. In the present study we investigated the presence, localization, and effects on human spermatozoa of 2 proteins of seminal plasma origin, uteroglobin (UG) and transglutaminase (TG). These 2 proteins interact with one another because TG promotes covalent links of UG to sperm surface proteins. We found that UG is localized around the entire surface of ejaculated human sperm, whereas TG is predominantly localized in the neck. FACScan analysis confirmed the surface localization of both antigens and demonstrated that swim-up selection of spermatozoa was associated with a significant reduction in the contents of the 2 substances when compared with unselected samples. Western blot analysis of UG in total sperm lysates confirmed the lower content of the protein in swim-up-selected sperm. Swim-up-selected sperm were characterized by their ability to undergo a spontaneous, time-dependent increase of capacitation-characteristic chlortetracycline pattern of fluorescence and increase in responsiveness to progesterone. Such changes were not observed in unselected sperm. Exogenous addition of TG, together with recombinant rabbit UG, prevented the spontaneous increase in responsiveness to progesterone (acrosome reaction and intracellular calcium) at 24 hours in swim-up-selected sperm, suggesting the occurrence of a capacitation-inhibiting activity of the 2 substances. In addition, we found that endogenous UG and TG contents, as determined by FACScan analysis, were negatively correlated (P < .0001) with sperm motility and that exogenous addition of the 2 substances resulted in a substantial reduction of progressive motility (P < .01). Collectively, these data indicate that TG and UG represent 2 DFs, and contribute to understanding the biochemical mechanisms that characterize the process of capacitation.     

高效液相色谱法测定淡豆豉药材中异黄酮的含量

目的:建立高效液相色谱法测定淡豆豉中异黄酮含量。方法:采用HPLC法,色谱柱为YWG C18柱(250 mm×4.5 mm,10μm),以甲醇-水-乙酸(10:10:1)为流动相,流速为0.8 mL·min-1,检测波长260 nm,测定淡豆豉中染料木素(genistein)、大豆黄素(daidzein)含量。结果:染料木素及大豆黄素的线性范围分别为2.00-40.00μg·mL-1和2.64-52.70μg·mL-1,相关系数分别为0.9994和0.9993,不同产地的淡豆豉中异黄酮含量差异较大。结论:本法准确、简便、快速,对于控制和评价淡豆豉的品质有重要意义。     

循环式扩张治疗食管化学灼伤后狭窄20例

目的　探讨食管化学灼伤后狭窄的简单、有效治疗方法 .方法　胃造瘘术后 ,食管内置入丝线 ,从鼻腔和胃造瘘口拉出连结 .用自制的食管扩张器 ,在丝线引导下进行扩张 .结果　食管上段狭窄 4例 ,中段 4例 ,下段 2例 ,全程不规则线状狭窄 1 0例 .经 3～ 8m o间断扩张治疗 ,全部顺利通过 1 8mm扩张器 ,进普食顺利 .经 2～ 5 a随访 ,效果良好 .结论　食管化学灼伤后狭窄行循环式扩张治疗是一种简单、有效、安全、经济的好方法 ,值得推广应用