Generation of High Yields of Syrian Hamster Cholangiocellular Carcinomas and Hepatocellular Nodules by Combined Nitrite and Aminopyrine Administration and Opisthorchis viverrini Infection

Combined administration of 0.1% nitrite and 0.1% aminopyrine in the drinking water for eight to ten weeks resulted in subsequent development of both hepatocellular nodules and cholangiofibrotic lesions/cholangiocellular carcinomas in Syrian golden hamsters. Additional prior dosing with Opisthorchis viverrini metacercariae (100/animal) induced inflammatory and proliferative changes in the livers of infected hamsters and was associated with a significant increase in yields of hepatocellular and cholangiocellular preneoplastic and neoplastic lesions. Thus, environmental factors thought to be casually related to the high levels of human liver cancer observed in the Northeastern provinces of Thailand were sufficient to bring about development of equivalent tumors in experimental animals. The results indicate that parasite associated liver injury and non-specific compensatory regeneration may play an important role in generation of both hepatocellular and cholangiocellular carcinomas in man.     

Augmenting Effect of a Nonmutagenic Fraction in Soy Sauce on Mutagenicity of 3-Diazotyramine Produced in the Nitrite-treated Sauce

When 25 kinds of Japanese soy sauce at a concentration of 5% were incubated with 50m M sodium nitrite (pH 2) at 37° for 1 hr, the reaction mixtures induced 34-834 (average 368 × 228) revertants per microliter of soy sauce equivalent in Salmonella typhimurium strain TA100 in the absence of S9 mix. The mutagen(s) formed was very unstable under natural daylight and a fluorescent lamp but quite stable under a yellow lamp as well as in the dark. In addition to the known precursors, i.e., tyramine and 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid, 1-methyl-1,2,3,4-tetrahydro-β-carboline, which caused weak mutagenesis, was found in the soy sauce. However, the sum of the activities of the three mutagen-precursors after nitrite treatment accounted for only a part of the mutagenicity of nitrite-treated soy sauce. There was in the soy sauce a factor which increased ninefold the mutagenicity of nitrite-treated tyramine, 3-diazotyramine. Therefore, tyramine was considered the principal precursor of the mutagen produced in the nitrite-treated soy sauce. These three precursors together with the mutagenicity augmentation accounted for all the mutagenicity of nitrite-treated sauce. The mutagenicity-augmenting factor in the soy sauce was nonmutagenic before and after nitrite treatment and was stable to heat and light irradiation.     

Effect of cyanide antidotes on the metabolic conversion of cyanide to thiocyanate

The excretion of thiocyanate following the administration of equitoxic doses of cyanide to unprotected mice and to animals pretreated with various cyanide antidotes has been studied.The results demonstrate that cyanide given alone or to animals pretreated with thiosulfate is extensively converted to thiocyanate. Animals pretreated with sodium nitrite or a combination of nitrite and sodium thiosulfate excreted even higher amounts of thiocyanate. This demonstrates that cyanide originally detoxified by combination with methemoglobin is ultimately converted to thiocyanate in the animal body.Pretreatment of animals with cobalt compounds (cobaltous chloride or dicobalt-EDTA) or a combination of cobalt compounds and thiosulfate resulted, on the other hand, in a less efficient conversion of cyanide to thiocyanate. The cyanide detoxified by trapping as highly undissociated cobalt-cyanide complexes is instead excreted in the urine, as demonstrated by detection of high amounts of cobalt ions and strongly complex-bound cyanide in the urine from animals treated with cobalt compounds and cyanide. A method for the determination of cyanide present as cobalt-cyanide complexes is described and its forensic application is proposed.     

Can Urinary Nitrite Results Be Used to Conduct Antimicrobial Option for Urinary Tract Infection in Children?

Objective

This study was performed to determine the relationship between urinary nitrite results and bacterial resistance to antimicrobial drugs in urinary tract infection of children.

Methods

In a cross-section study 119 children younger than 12 years with urinary tract infection were evaluated in Qazvin children''s hospital. Patients were divided into negative and positive nitrite groups depending on urinary nitrite test result. Rates of antibiotic resistance in the two groups were compared.

Findings

Sixty seven patients were in the negative nitrite group and 52 in the positive nitrite group. Resistance rates to ceftriaxone, trimethoprim sulfamethoxazole, ampicillin, gentamicin, amikacin, nalidixic acid, cephalothin and nitrofurantoin in the nitrite negative group were 7.5%, 31.3%, 50.7%, 11.9%, 9%, 3%, 14.9% and 11.9%, respectively. These values in the nitrite positive group were 21.2%, 28.8%, 63.5%, 7.7%, 5.8%, 1.9%, 9.6%, and 3.8%, respectively (P>0.05).

Conclusion

This study showed that there is no correlation between urinary nitrite results and bacterial resistance to antimicrobial drugs. Therefore, it seems that physicians should not adjust antibiotic therapy for UTI based on nitrite results.     

天津市部分市售熟肉制品亚硝酸盐含量的风险监测

目的对天津市部分市售熟肉制品中亚硝酸盐检出量进行风险监测。方法于2010年随机抽取天津市市售的180份熟肉制品样本,样本均采自天津市各个饭店。结果 180份样品中亚硝酸盐的检出量为0.93～158 mg/kg。合格174份,样本合格率为96.7%。结论该市熟肉制品中仍有少量样本亚硝酸盐超标,应继续加强监督检测和宣传工作。     

2009～2010年泉州市瓶(桶)装矿泉水纯净水卫生状况分析

[目的]了解泉州市桶(瓶)装矿泉水纯净水卫生状况,确保消费者的饮水安全。[方法]依据GB/T 8538-2008《饮用天然矿泉水检验方法》、GB 8537-2008《饮用天然矿泉水》、GB/T 5750-2006《生活饮用水标准检验方法》和GB17324-2003《瓶(桶)装饮用纯净水卫生标准》的方法进行检验和统计分析。[结果]2009年共检测瓶(桶)装矿泉水48份,纯净水58份,其中亚硝酸盐合格率分别为85.42%和94.83%;2010年共检测瓶(桶)装矿泉水26份、纯净水31份,其中亚硝酸盐合格率分别为73.08%和83.87%,呈下降趋势。[结论]我市瓶(桶)装矿泉水纯净水的亚硝酸盐污染情况不容乐观,加强监管,建立有效的卫生监督机制势在必行。     

一起就餐后引起胃部不适症状投诉的调查及分析

目的 对一起就餐后引起胃部不适症状的投诉进行调查及分析. 方法 亚硝酸盐依据GB5009.33-2010进行检测,菌落总数、沙门菌、金黄色葡萄球菌依据GB4789.2,4,10-2010进行检测,大肠菌群、志贺菌依据GB4789.3,5-2003进行检测. 亚硝酸盐依据GB2760-2011《食品添加剂使用标准》进行判定. 结果 患者呕吐物亚硝酸盐含量为7.90 mg/kg,筒子骨炖萝卜样品中亚硝酸盐含量为29.84 mg/kg.样品中未检出致病菌.结论少量亚硝酸盐引起的轻度食物中毒症状不明显,容易出现误诊,要进一步加强对亚硝酸盐使用的监管.     

Nitric oxide donors offer protection to RBC from storage lesion

BackgroundRed blood cell (RBC), which is the most commonly transfused blood component, due to its ability to save a life in absence of any other blood components, can be stored up to maximum 6 weeks by following standard preservation procedure. During storage, RBC undergoes various biophysical and biochemical changes (commonly known as storage lesion) for which blood transfusion with “old RBC” shows a lot of clinical problems especially relevant to critically ill patients. Recent research on S-nitrosylation of haemoglobin to improve oxygen delivery of banked blood revealed the important role of nitric oxide (NO) in protecting storage lesion.Materials and methodsIn the present study, we used various “NO donating” chemicals with different NO release dynamics and chemistries in RBC storage cocktails to test the effects of NO on storage lesion. Changes in different storage markers were evaluated after 7 days storage of pre-treated RBC.ResultsAll the NO donors have shown protection against hemolysis. However, S-nitroso glutathione (GSNO) ranks first in shielding RBCs from storage lesion and additionally, it helps in elevating the value of 2, 3-di phosphoglycerate (2, 3-DPG), improving the RBC membrane fluidity and decreasing the adhesion towards endothelial monolayer.DiscussionPresent study reveals that NO released from NO donors confers protection against storage lesions of the RBC. Further, the study confirms that pre-treatment with GSNO, a NO donor and a nitrosylating agent, ensures the best protection to RBC during low temperature storage, when compared to other NO donor treatments.     

新型双启动子表达质粒pCMVnir的构建及其促进基因免疫效果的研究

目的 构建一种新型双启动子表达载体pCMVnir，研究其与胞内寄生菌联合应用促进基因免疫效果的作用。方法细菌硝酸盐还原酶基因B启动子nirB为厌氧诱导启动子，根据nirB启动子的结构，设计合成改良的nirB，置换三启动子载体pTriEx-4中的T7Lac和P10启动子，而保留其CMVie启动子，获得携带CMVie和nirB双种启动子的新型载体pCMVnir，或称为pCN。构建pCN-EGFP和pCN-DsRed两种报告质粒，分别转化S．SL3261、E．coil DH-15a和CHO等细胞，检测报告基因的表达情况以确定两种启动子的活性。pCN-EGFP转化S．SL3261，接种BALB／c小鼠，定期解剖小鼠收集黏膜相关淋巴组织，观察重组细菌和载体DNA在细胞中的定植及稳定性。免疫接种小鼠，并定期收集小鼠血清和阴道分泌物，以重组rEGFP为抗原，用EEISA方法研究其增强免疫应答的能力。并构建人乳头瘤病毒L1E7双启动子pCN-16L1E7及对照单启动子载体pCMV-16L1E7和pNir-16L1E7，对比三者涛导黏膜免疫的差别。结果双启动子表达载体pCMVnir可在细菌和真核细胞中有效表达报告基因，在细菌中可形成肉眼可见的荧光菌落和沉淀，转染CHO等真核细胞能够表达荧光蛋白，表明pC-MVnir载体的两种启动子都有活性，其中nirB活性是受兼性厌氧调控的。pCMVnir与细菌有较好的相容性，重组细菌可在动物体内有限复制和定植达6周，质粒可在细菌中稳定存在。以rEGFP为抗原检测发现pCN-EGFP诱导的免疫反应高于常用的单启动子载体pCMV-EGFP。人乳头瘤病毒双启动子载体pCN-16L1E7诱导的免疫反应也高于其他单启动子载体。结论双启动子表达载体pcMVnir与减毒胞内寄生菌匹配应用，能够提高抗原表达量及增强基因免疫反应的强度。并可作为一般基因克隆和表达载体，特别是作为原核表达载体，不用添加诱导物，即可获得大量表达。     

雷公藤多苷的抗炎作用与NO的关系

 目的:研究雷公藤多普的抗炎作用与NO的关系。方法:采用锡还原柱层析和Griess比色法,测定NO的稳定代谢产物NO₂〈sup〉-〈/sup〉-(NO₂〈sup〉-〈/sup〉)。结果:雷公藤多等对正常大鼠血、尿中亚峭酸盐(稍酸盐)[NO₂〈sup〉-〈/sup〉(NO₃〈sup〉-〈/sup〉),μmol·L^-1]含量无显著影响;雷公藤多普能不同程度地抑制角叉菜胶所致的大鼠足拓肿胀,同时剂量依赖性地降低血清、尿液和炎性足拓组织中NO₂〈sup〉-〈/sup〉(NO₃〈sup〉-〈/sup〉)含量;雷公藤多普能使棉球肉芽肿大鼠模型中棉球肉芽肿重量减轻,同时可剂量依赖性地降低血清、尿液和炎症组织中NO₂〈sup〉-〈/sup〉(NO₃〈sup〉-〈/sup〉)的含量。其减轻棉球肉芽肿作用与降低肉芽组织中NO含量呈明显正相关(r=0.9978)。结论:雷公藤多普对正常大鼠体内NO的产生没有影响;其抗炎(大鼠角叉菜胶性足书肿胀和棉球肉芽肿)作用与抑制其体内NO水平有关。