甲醛致大鼠肺和肾组织细胞DNA-蛋白质交联及其修复研究

目的为探讨甲醛致生物机体DNA-蛋白质交联(DPC)作用及其修复能力。方法以3月龄SPF级健康成年雄性Wistar大鼠为实验动物分别进行体内(0、0.5、1.0、3.0mg/m3气态甲醛吸入染毒72h)和体外实验(0、25、50、100、150、200μmol/L液态甲醛染毒1h),并进行体内(3.0mg/m3的气态甲醛吸入染毒72h)和体外(75μmol/L的液态甲醛染毒1h)修复实验(修复0、6、12、18和24h)。采用KCl-SDS沉淀法检测大鼠肺、肾组织细胞DPC率。结果体内实验表明,低浓度的气态甲醛(0.5mg/m3)不能明显诱导大鼠肺、肾组织细胞产生DPC,较高浓度的气态甲醛(≥1.0mg/m3)可以产生明显的DPC作用(P<0.05);由3.0mg/m3浓度的气态甲醛使肺、肾组织细胞产生的DPC可在24和18h内得到修复,并可在24h内恢复到空白对照水平。体外实验表明,低浓度的液态甲醛(25μmol/L)不能明显诱导大鼠肺、肾组织细胞产生DPC,较高浓度的液态甲醛(≥50μmol/L)可以产生明显的DPC作用(P<0.05);由75μmol/L浓度的液态甲醛使肺、肾组织细胞产生的DPC可以在1...     

甲醛致大鼠离体骨髓细胞DNA-蛋白质交联的研究

目的检测经不同浓度甲醛染毒后所致大鼠骨髓细胞的DNA-蛋白质交联程度。方法采用KCl-SDS沉淀法检测液态甲醛所致DNA-蛋白质交联（DPC）效应。结果低浓度的甲醛（10μmol／L和50μmol／L）能引起DNA-蛋白质的交联；较高浓度的甲醛（250μmol／L和1250μmol／L）可以产生明显的DNA-蛋白质交联作用（P〈0．01）。结论甲醛可造成骨髓细胞DNA-蛋白质交联，而DPC可以对细胞产生严重的遗传毒性，这可能是甲醛导致白血病的分子机制之一。     

微囊藻毒素-LR致小鼠肝、肾和睾丸细胞DNA-蛋白质交联的研究

目的探讨微囊藻毒素-LR所致小鼠肝、肾、睾丸细胞DNA-蛋白质交联(DPC)作用。方法以昆明种雄性小鼠为实验对象,腹腔注射染毒,采用KCl-SDS沉淀法检测小鼠肝、肾、睾丸细胞中交联DNA和游离DNA的量,计算其DPC系数,DPC系数=交联DNA/(交联DNA+游离DNA),判断DNA与蛋白质的交联程度。结果在小鼠肝细胞中,微囊藻毒素-LR各染毒组DPC数量均有显著增加,其DPC系数与对照组相比差异均有显著性(P<0.05)。在小鼠肾细胞中,微囊藻毒素-LR染毒剂量为3μg/kgbw和6μg/kgbw时,DPC数量显著增加,其DPC系数与对照组相比差异有显著性(P<0.05);染毒剂量为12μg/kgbw时,DPC数量未增加,其DPC系数与对照组相比差异无显著性(P>0.05)。在小鼠睾丸细胞中,染毒剂量为3μg/kgbw时,DPC数量未增加,其DPC系数与对照组相比差异无显著性(P>0.05)。染毒剂量为6μg/kgbw和12μg/kgbw时,DPC数量显著增加,其DPC系数与对照组相比差异有显著性(P<0.05)。结论在一定的染毒剂量下,微囊藻毒素-LR可以引起小鼠肝、肾、睾丸细胞DNA-蛋白质交联。     

姜黄素对甲醛致A549细胞DNA-蛋白质交联损伤的拮抗作用

为探讨姜黄素对甲醛致A549细胞DNA-蛋白质交联(DPC)的拮抗效应,采用培养A549细胞株作为实验材料,分为正常对照组、0.1 mmol/L甲醛组、姜黄素拮抗组(2.5、5.0、10.0、20.0 mg/L姜黄素+0.1 mmol/L甲醛组),对细胞染毒4 h后采用氯化钾-十二烷基硫酸钠沉淀法检测DPC率。结果显示,0.1 mmol/L甲醛染毒组DPC率高于对照组(P0.05),各姜黄素拮抗组DPC率均低于0.1 mmol/L甲醛组,但2.5、5.0、10.0 mg/L姜黄素拮抗组的DPC率高于对照组,差异均有统计学意义(P0.05),20.0 mg/L姜黄素拮抗组DPC率与对照组差异无统计学意义(P0.05)。提示较高浓度的姜黄素可以拮抗甲醛所致的DNA-蛋白质交联损伤。     

邻苯二甲酸二乙基己酯致小鼠不同器官细胞 DNA-蛋白质效应研究

目的为了探讨邻苯二甲酸二乙基已酯（DEHP）导致生物机体内不同器官DNA-蛋白质的交联（DPC）作用。方法以采用KCl-SDS沉淀法来检测DEHP体外染毒后昆明纯系小鼠体内肝、脑、睾丸、肺等4个器官的细胞中DNA-蛋白质交联含量。结果当DEHP的浓度为5μM时,小鼠肝细胞的DPC系数与对照组相比没有发生显著的变化;当DEHP的浓度分别升高到10、20、40和80μM时,DPC系数显著上升,且DPC含量与对照组相比有极显著差异;在脑细胞中,当DEHP的浓度分别为5、10μM时,能显著诱导DPC的生成（P〈0．05）,但是,随着DEHP的浓度升高,DPC的含量与对照组相比没有显著性差异;在睾丸的细胞中,当DEHP的浓度为5μM时,小鼠睾丸的细胞DPC系数与对照组相比有显著的升高（P〈0．05）;当DEHP的浓度升高到10、20、40、80μM时,DPC系数显著上升,且DPC含量与对照组相比有极显著差异（P〈0．01）;在肺细胞中,DEHP的浓度为5μM时,就能显著诱导DPC的生成（P〈0．05）。结论DNA-蛋白质交联是一种严重的DNA损伤。DEHP可诱导DNA-蛋白质交联的产生。     

甲醛吸入致小鼠脑和肾组织的氧化损伤作用研究

目的研究小鼠吸入气态甲醒后，甲醒对小鼠的脑、肾组织蛋白造成氧化损伤和脂质的过氧化及其发生机制。方法用不同剂量的气态甲醛对小鼠进行连续动态染毒处理72h，用2，4-二硝基苯肼比色法测定小鼠脑、肾组织蛋白质的羰基古量，以判断蛋白质的氧化损伤程度；用MDA（丙二醛）试剂盒测定组织中MDA含量，来判断脂质的过氧化程度。结果只有吸入3．0mg／m^3的气态甲醛时，才会对脑、肾组织中的蛋白质造成明显的氧化损伤，而在0．5mg／m^3时，脑组织中脂质的过氧化比肾组织中显著。结论0．5mg／m^3的气态甲醛不造成蛋白质氧化损伤，而对脑组织中脂质的过氧化作用却很显著，可见0．5mg／m^3甲醛对生物体存在着直接的神经毒性;3．0mg／m^3的气态甲醛对脑、肾组织中的蛋白质和脂质会造成明显的氧化损伤，且肾组织比脑组织敏感。     

甲醛和苯联合吸入致雄性小鼠骨髓细胞的遗传毒性

[目的]研究甲醛和苯联合吸入染毒对雄性小鼠骨髓细胞的遗传毒性作用。为评价甲醛和苯的安全性提供科学依据。[方法]60只健康清洁级昆明种纯系雄性小鼠,随机分为10组,每组6只。各组分别为阴性对照组（清洁空气）,甲醛低（1．0mg／m^3）、中（3．0mg／m^3）、高（5．0mg／m^3）剂量组;苯低（500．0mg／m^3）、中（1500．0mg／m^3）、高（2500．0mg／m^3）剂量组,联合染毒低（0．5mg／m^3甲醛＋250．0mg／m^3苯）、中（1．5mg／m^3甲醛＋750．0mg／m^3苯）、高（2．5mg／m^3甲醛＋1250．0mg／m^3苯）剂量组。采用静式吸入染毒,每天2h,连续14d。染毒结束次日处死小鼠,采用微核试验和单细胞凝胶电泳试验（彗星试验）检测甲醛和苯单独或联合染毒致骨髓细胞的遗传毒性。[结果]与阴性对照组相比,甲醛、苯单独及联合染毒各剂量组均呈现骨髓细胞微核率升高、彗星尾部DNA含量增多、尾距增大（P〈0．05）。与相应单独染毒组相比,联合染毒各剂量组骨髓细胞微核率明显升高（P〈0．05）;联合染毒低、中剂量组彗星尾部DNA含量增多、尾距增大（P〈0．05）;联合染毒高剂量组彗星尾部DNA含量和尾距高于甲醛高剂量染毒组（P〈0．05）,与苯高剂量染毒组比较,其差异无统计学意义。[结论]甲醛和苯联合吸入染毒对雄性小鼠骨髓细胞的遗传损伤作用大干甲醛、苯单独染毒时的作用,二者对雄性小鼠骨髓细胞的联合遗传毒性作用可能具有协同作用。     

邻苯二甲酸二丁酯对体外大鼠肝脏细胞的氧化损伤作用

目的探讨邻苯二甲酸二丁酯（DBP）对大鼠肝脏细胞的急性氧化损伤作用。方法用0、5、20、80μmo·lL^-1的DBP溶液对大鼠肝脏细胞进行体外染毒1h,然后分别用硫代巴比妥酸（TBA）法和KCl-SDS沉淀法来检测丙二醛（MDA）含量和DNA-蛋白质交联（DPC）系数的变化。结果随着DBP染毒浓度的升高,大鼠肝脏细胞的MDA含量和DPC系数逐渐上升,且在5μmo·lL^-1浓度时就与对照组具有良好的统计学意义（P〈0.01）。结论DBP能够对体外大鼠肝脏细胞造成氧化损伤。     

气态甲醛致小鼠脑细胞遗传毒性的研究

目的检测经不同浓度气态甲醛暴露后所致小鼠脑细胞的遗传损伤。方法用不同剂量气态甲醛（0．5，1．0和3．0mg／m^3）对小鼠进行连续动态染毒处理72h，利用单细胞凝胶电泳技术（又称彗星实验）检测脑细胞的DNA损伤。结果吸人浓度为0．5和1．0mg／m^3的甲醛后，可造成脑细胞DNA的严重断裂，而3．0mg／m^3的甲醛则引起显著的交联作用。结论气态甲醛可造成脑细胞DNA的断裂和交联.     

亚急性甲醛吸入对小鼠肝细胞DNA损伤作用

目的检测亚急性甲醛吸入对小鼠肝细胞的损伤作用,并探讨用归一化处理方法解决单细胞凝胶电泳重复性差的可行性.方法将小鼠分别暴露于不同浓度的气态甲醛（0.5,1.0和3.0 mg/m^3）中染毒14d,每天6 h,用单细胞凝胶电泳技术检测肝细胞DNA的损伤程度.结果0.5和1.0 mg/m^3的甲醛可造成DNA的严重断裂（P＜0.001）,而3.0mg/m^3的甲醛则引起显著的交联作用,归一化的结果与之相符,并表明不同浓度的甲醛导致不同程度和类型的DNA损伤.结论甲醛可造成机体内肝细胞DNA的断裂和交联,该损伤可能是甲醛致癌机制之一;归一化可以弥补单细胞凝胶电泳实验重复性不佳的缺陷.     

Trends in meningococcal disease in Italy in 1988

Meningococcal disease in Italy decreased 15% in 1988 from the previous year (290 vs. 342 cases). The decline was particularly evident in military cases (1.7/100,000 in 1988 vs. 5/100,000 in 1987) reflecting the full coverage of bivalent serogroup (A + C) meningococcal polysaccaride vaccine in army recruits, achieved since January 1988. The highest proportion of cases was seen in people older than 25 years of age (25%). Serogroup C constituted 60% of the isolates, while 19% belonged to serogroup B. The proportion of strains resistant to sulphonamides was 45%, while 15% were resistant to Minocycline and none to Rifampin. Out of the five military cases, only one (due to serogroup C) was attributable to the vaccine failure. A single coprimary case, but no secondary cases occurred among civilians. These findings are consistent with the trends reported in Italy in the previous years.     

Benzene in blood and phenol in urine in monitoring benzene exposure in industry

Determinations of benzene concentration in blood and of phenol in urine were made by head-space gas chromatography techniques on samples taken near the end of the work day from two groups of workers potentially exposed to low levels of benzene in the work-place atmosphere. Preliminary results suggest that benzene in blood is more reliable than phenol tests for assessing both exposure and uptake of benzene. Normal values of phenol in urine (10 mg/liter or less) were found in nearly all those cases in which benzene was detected in the blood.     

2015年郑州市饮用水放射性水平状况调查

目的了解郑州市不同地区、不同季节、不同水源类型的放射性水平。方法分别于丰水期和枯水期采集郑州市区黄河水源水、井水源水、丹江口水源水、出厂水和末梢水各一份;以县为单位,每单位采集出厂水、末梢水、水库水、河水、井水各1份,按《生活饮用水生活标准检验方法》(GB/T 5750.13-2006)检测饮用水中总α和总β放射性水平,依据《生活饮用水卫生标准》(GB 5749-2006)进行判定。结果丰水期、枯水期水体总α、总β放射性水平均低于国家标准限值。结论郑州市不同水源类型均处于正常的天然放射性本底水平。     

Occupational stress in nurses in psychiatric institutions in Taiwan

Nurses are known to be exposed to occupational stress. However, occupational stress is not well documented for nurses in psychiatric institutions in Taiwan. A cross-sectional study was conducted to explore the work-related stress and risk factors of nurses in psychiatric institutions in Taiwan. A structured questionnaire was distributed to nurses at five state-owned psychiatric hospitals in Taiwan in 2001. Demographic information, working environment, and personal health status were inquired. Occupational stress was assessed based on the Chinese version of Job Content Questionnaire (JCQ). General health status and mental health were evaluated by the International Quality of Life Assessment Short Form-36 (IQOLA SF-36). A total of 573 questionnaires were disseminated to nurses and 518 (90.4%) were satisfactorily completed by nurses, including 408 female full-time nurses who had been in their current work for more than 6 months. In the past one month, 17.2% of nurses reported being under significant stress often or always. Assault episodes were reported by 45.1% of nurses in the past 6 months. Among the nurses, 16.9%, 25.2%, 50.0%, and 7.8% belong to the "High strain", "Low strain", "Active", and "Passive" groups, respectively. Perceived occupational stress was associated with young age, widowed/divorced/separated marital status, high psychological demand, low workplace support, and threat of assault at work. Lower general health score was associated with low job control, high psychological demand, and perceived occupational stress. A lower mental health score was associated with low job control, high psychological demand, low workplace support, and perceived occupational stress. We concluded that nurses in psychiatric institutions are under significant stress related to work factors.     

Changes in nursing administration in supporting transplantation in Brazil

This historical and bibliographic study aimed to understand how Nursing was organized to support care in transplantation. The HISA, LILACS, BDENF, PERIENF and DEDALUS databases were consulted, and thirteen references were found, ten of which were scientific articles, two were master's dissertations and one was a doctoral thesis. The span of time chosen for study ranges from the date of the first kidney transplant in Brazil (1965), to the date of publication of the last scientific article found in the databases mentioned above (2003). After reading these articles, the ones that were similar in topic were grouped together, thus creating the thematic axis for the presentation of the results. The results showed that the Nursing profession has played an important and active role in transplants ever since the first procedure in 1965.     

2019年中国肿瘤流行病学研究进展

恶性肿瘤已成为中国居民的主要死因之一。近些年来,中国政府积极推进肿瘤预防和控制领域的研究工作,取得了很大的进步。本文简要汇总中国在肿瘤流行病学领域的研究进展,具体包括2019年的肿瘤负担、癌症危险因素及其干预、筛查和早期发现、癌症防治专项行动(2019-2022年)方案等方面,以期为我国肿瘤防治工作的有效开展提供技术支撑和理论依据。     

2012年绵阳市蔬菜中农药残留状况

目的 了解绵阳市2012年市售蔬菜中农药残留情况,为食用蔬菜监管提供依据.方法 全部样品均按照GB/T 5009-2003的方法进行农药的残留检测.依据GB 2763-2005《食品中农药最大残留限量》进行判定.结果 2012年共检测蔬菜165份,农药检出率和超标率分别为72.12％和23.64％.豆类、根茎类、叶菜类、瓜果菜类和食用菌类蔬菜检测农药残留超标率分别为8.00％、23.53％、36.00％、5.26％和27.03％,差异有统计学意义(x2=11.41,P＜0.01).不同种类农药超标率差异有统计学意义(x2 =62.42,P＜0.01).夏季和冬季蔬菜农药超标率差异无统计学意义(x2=3.44,P＞0.05).结论 绵阳市叶菜类蔬菜中农药残留情况较为严重,应采取有效措施,加强蔬菜的监督管理,从源头禁止高毒农药的使用,加大蔬菜种植、销售环节的监测,确保市民食用蔬菜的安全.