亚硝酸盐中毒及其预防措施

亚硝酸盐是N-亚硝基化合物。它可通过各种污染途径进入食物，也可由食物中广泛存在的亚硝基化合物前体在适宜条件下生成。近期，全国发生多起亚硝酸盐食物中毒事件，如山西省晋中市“万家灯火大酒店”非法使用亚硝酸盐造成168人中毒，湖北省咸宁一家庭因误食亚硝酸盐造成3人中毒2人死亡等。故亚硝酸盐中毒在日常生活中的预防措施非常重要。     

NO_2~-诱发癌症的作用机制

大量动物实验和流行病学调查表明,环境中亚硝酸盐浓度的升高能够导致癌症的发生。到目前为止,对于亚硝酸盐诱发癌变已经进行了大量的研究,其作用机制已经引起了广泛的关注。本文分析了外界亚硝酸盐含量的升高对体内N-亚硝基化合物和NO含量的影响,综述了N-亚硝基化合物和NO致癌的作用机制,并对亚硝酸盐引起癌变的其他机制进行了探讨。认为亚硝酸盐通过刺激体内N-亚硝基化合物和NO的生成,导致癌变的发生,同时亚硝酸盐刺激肿瘤新血管生成和亚硝酸盐作为癌变细胞糖酵解的氢受体也对癌变的发生起了重要作用。     

冰箱与胃癌

在冰箱普及之前，人们经常用腌制或烟熏的办法保存食物，而这样的食物中含有大量的硝酸盐和亚硝酸盐，在胃中可转化为致癌的N-亚硝基化合物，从这个方面说，冰箱的普及和正确使用降低了胃癌的发病率。[第一段]     

蔬菜中亚硝酸盐含量变化观察

亚硝酸盐是一种有毒物质 ,过量摄入可引起急性中毒。另外 ,它在适宜条件下与伯胺仲胺等结合 ,生成N一亚硝基化合物。N一亚硝基化合物具有强烈的致癌性 ,已知可使多种动物 ,多种器官组织产生肿瘤 ;少量多次长期摄入或一次冲击量均可致癌。至今尚未发现有一种动物对N一亚硝基化合物的致癌作用有抵抗力。尽管目前对N一亚硝基化合物是否对人类有致癌性尚无定论 ,但对某些地区与国家的流行病学资料的分析 ,表明人类某些癌症可能与之有关[1 ] 。因此 ,食物中的亚硝酸盐含量已引起食品卫生界的广泛重视 ,为观测蔬菜中亚硝酸盐的含量变化 ,我们以…     

虾米、咸鱼、咸蛋、咸菜中亚硝酸盐含量调查分析

亚硝酸盐是N-亚硝基化合物的前体物.现已确定N-亚硝基化合物对动物有较强的致癌作用[1].亚硝酸盐可以经过化学或生物学的途径合成多种多样的N-亚硝基化合物,而亚硝胺的形成浓度和亚硝酸盐的平方成正比[2].     

从食物中每日摄入N-亚硝基化合物的量

N-亚硝基化合物广泛分布于环境和食物中,1982年Druckrey等首先报告,该化合物对多种动物显示强烈的致癌作用。其后Sandar等报道胺和亚硝酸可在机体内生成亚硝胺,自此引起食品卫生学界的关注。有人曾按各种食物的分析值,用数据处理机推断N-亚硝基化合物的摄入量。本文报告日本人平时饮食中,摄入N-亚硝基化合物的程度,以及含大量N-亚硝基化合物的前驱物质的食物,经混合、加热后N-亚硝基化合物的生成情况。     

硝酸盐、亚硝酸盐及N-亚硝基化合物与人类先天畸形

环境中的硝酸盐暴露与婴儿高铁血红蛋白血症及食管癌的病因关联已为人们熟悉.此外,国内外许多研究表明,硝酸盐、亚硝酸盐暴露可能与人类先天畸形的发生有关.该文介绍了环境中硝酸盐、亚硝酸盐以及N-亚硝基化合物的暴露、相互转化以及与人类先天畸形关系的研究进展.     

亚硝化农肥水中N-亚硝基化合物的分析

目的分析亚硝化农肥水中N-亚硝基化合物的种类。方法使用特异的高效液相色谱—光水解、热裂解—热能分析仪联机技术(HPLC-PHPS-TEA)进行分析检测。结果在亚硝化农肥水中发现N-亚硝基甲基脲(MNU),二甲基亚硝胺(NDMA);结论农肥水中含N-亚硝基化合物的胺类、酰胺类前体物:二甲胺和甲基脲。亚硝化农肥水中含有N-亚硝基化合物:二甲基亚硝胺和N-亚硝基甲基脲。这是两种能引起动物胃癌、食管癌和肝癌的N-亚硝基化合物。因此,从环境微生物、环境化学角度为"食管癌、胃癌和肝癌的氮循环——N-亚硝基化合物前体物病因假说"提供了有力的佐证。另外,使用我们的专利《消除饮用水中N-亚硝基化合物及其前体物的方法》作为干预措施,经过干预处理的农肥水,不管是否亚硝化,均无N-亚硝基化合物。证明专利方法有效,可以直接应用于食管癌、胃癌和肝癌的病因预防。     

市售熟肉制品中亚硝酸盐含量的调查分析

<正>亚硝酸盐具有较强的氧化性和抑菌效果,常作为防腐剂和着色剂应用于熟肉制品的生产加工中〔1〕。但亚硝酸盐能与食物中的仲胺、叔胺等反应生成强致癌物N-亚硝胺〔2-3〕,摄入量过大会对人体健康造成慢性危害或急性食物中毒。据资料报道,摄入亚硝酸盐0.3~0.5 g即可中毒,3 g可致人死亡〔4〕。GB 2760-2011《食品添加剂使用标准》规定熟肉制品中的亚硝酸盐含量(以亚硝酸钠计)不     

亚硝酸盐和二甲胺对大鼠的毒性

硝酸盐和亚硝酸盐的主要危害是在体内产生N-亚硝基化合物。动物实验已证实几种N-亚硝基化合物为致癌原。已知化学致癌物代谢过程中产生的自由基与致癌作用有关。N-亚硝基化合物转变为终致癌物的过程中也产生自由基。抗氧化剂VitC、VitE、BHA(丁基羟基     

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.