甲萘威对雌性大鼠血清雌激素水平及抗氧化系统功能的影响

目的观察甲萘威对雌性大鼠的生殖毒性并初步探讨其机制。方法雌性SD大鼠经口染毒甲萘威,剂量为0、1.028、5.140、25.704mg·kg-1·d-1。阴道脱落细胞涂片法观察大鼠动情周期的变化;放射免疫法测定其血清雌二醇(E2)、孕酮(P4)水平;分光光度法测定其血清超氧化物歧化酶(SOD)、谷胱甘肽硫转移酶(GST)的活力以及丙二醛(MDA)、谷胱甘肽(GSH)的含量。结果各剂量甲萘威染毒组大鼠动情周期数明显低于对照组。染毒后15d大鼠动情各期出现变化,与对照组的差异有统计学意义(P<0.05,P<0.01)。25.704mg·kg-1·d-1组大鼠体重增长明显低于对照组。各剂量染毒组大鼠的多个脏器系数均明显降低。25.704mg·kg-1·d-1组大鼠血清中E2水平为(19.93±2.21)nmoll,1.028mg·kg-1·d-1组大鼠P4水平为(1.21±0.40)nmoll,与对照组[(28.76±6.12)、(0.63±0.39)nmolL]的差异均有统计学意义(P<0.05)。随染毒剂量增高,大鼠SOD活力在卵巢先降后升,在血清中略升后下降;MDA含量则呈在卵巢中渐升高、在血清中略升后降低趋势;GSH含量和GST活力在卵巢中呈先降后升趋势,但在血清中,GSH含量呈下降趋势,GST活力先上升后下降。结论甲萘威可致雌性大鼠动情周期紊乱及雌激素水平改变,对大鼠的抗氧化系统产生一定影响。     

快速测试有机磷和氨基甲酸酯成分的方法研究

目的快速检测市售卫生杀虫剂中是否含有机磷或氨基甲酸酯成分。方法用农药速测卡测试稀释后的卫生杀虫剂提取液。结果将检测结果用气相色谱法验证,蚊香准确率88.9%、灭蚊片100%、气雾剂33.3%,15个电热灭蚊片样品中没有发现含有机磷或氨基甲酸酯的产品。结论此方法可用于蚊香和灭蚊片初筛检测是否含有机磷或氨基甲酸酯。     

Amino acids and biogenic amines during spontaneous malolactic fermentation in Tempranillo red wines

This paper examines the changes undergone by the nitrogenated fraction of wine during malolactic fermentation (MLF) produced by the indigenous microbiota in 16 industrial-scale vinifications at technologically well-equipped wineries. Statistically significant increases (between 5% and 35%) were found in 15 of the 24 amino acids analyzed; decreases (between 4% and 29%) were found only in four. The biogenic amines histamine, tyramine and putrescine increased by between 106% and 174%, but histamine final concentrations in wine were not too high, under the limit of 10 mg/L established by Switzerland. There was a non-significant increase of 2.0–2.3 μg/L in ethyl carbamate.     

气相色谱法测定氯苯甘油氨酯中有机溶剂残留量

目的:测定氯苯甘油氨酯原料药中残留有机溶剂甲苯的含量。方法:采用气相色谱法,FID检测器,以二甲基亚砜为溶剂,正庚烷为内标,在GDX—401色谱柱上,应用程序升温,实现了各组分的基线分离。结果:甲苯在8.9～178μg·ml~(-1)浓度范围内,线性关系良好,回归方程为:Y=0.0119X+0.0019,r=0.9994。甲苯的最低检出限为4.4μg/ml,回收率为103.0％(n=6)。结论:经方法学试验验证,该方法灵敏、准确、可信,适用于原料药中有机溶剂残留量的测定。     

An automated method for the determination of acetyl and pseudo cholinesterase in hemolyzed whole blood.

The aim of the present study was to develop a method which allows determination of pseudo (PsChE) and acetyl cholinesterase (AChE) activities in single hemolyzed blood samples of workers exposed to cholinesterase-inhibiting compounds, avoiding the time-consuming and laborious separation of plasma and erythrocytes. Two methods based on Ellman's colorimetric determination of cholinesterase activity were compared, and three different substrates were tested. The best results were obtained with the substrates butyrylthiocholine and acetyl(beta-methyl)thiocholine, both showing a substrate specificity of more than 97% with respect to PsChE and AChE, respectively. The method showed sensitivity to detect low levels of inhibition of AChE and PsChE in blood. The between-day precision was less than 4% for both cholinesterase activities. It was demonstrated with this method that hemolyzed blood can be stored at -20 degrees C at least 18 months without loss of cholinesterase activity. The method has been used for 18 months in a monitoring program for laboratory employees working with various cholinesterase-inhibiting compounds. The average co-efficients of intraindividual variation amounted to 6.8% (range 2.2-9.6%; 90 percentile, 8%) and 6.6% (range 2.9-9.9%; 90 percentile, 7.9%) for PsChE and AChE, respectively. In a group of non-exposed workers the average intraindividual variations were 4.0% (range 1.5-7.7%; 90 percentile, 7.6%) and 3.6% (range 0.6-6.6%; 90 percentile, 5.3%), respectively. Using the value of 4.0%, it appears possible to detect an individual decrease in cholinesterase activity of more than 8% below a baseline based on three determinations. The method can thus be used to detect relatively low levels of cholinesterase inhibition.     

Protection and reversal by memantine and atropine of carbofuran-induced changes in biomarkers

Male Sprague-Dawley rats injected with a single acute dose of carbofuran (1.5 mg/kg, sc) developed chewing movements and fine tremors within 5–7 min. The signs of maximal severity with hypercholinergic preponderance including muscle fasciculations, convulsions, tracheobronchial secretions, and diarrhea were evident within 15–30 min and lasted for about 2 h. Various antidotal drugs, alone or in combination with atropine sulfate (ATS), were administered as pretreatment or as therapeutic measures to alleviate carbofuran-induced cholinergic toxicity. In fact, pyridine-2-aldoxime methylchloride (2-PAM) or diazepam alone or in combination with ATS did not provide any beneficial antidotal effects. Combined pretreatment with memantine (MEM, 18 mg/kg, sc) and ATS (16 mg/kg, sc) provided complete protection against carbofuran toxicity and reversal of clinical evidence when given therapeutically. Carbofuran intoxication caused significant alterations in the activities of biomarker enzymes such as creatine kinase (CK) and lactic dehydrogenase (LDH) and their isoenzymes patterns in serum as a result of their leakage from the target organs (brain, muscles, and heart). Significant increases in the levels of transaminases (GOT and GPT) and glucose were also noted, MEM in the aforementioned parameters, in addition to similar protective effects reported on target enzyme acetylcholinesterase (AChE). These results, along with those reported previously, indicate that MEM antagonizes carbamates toxicity by maintaining cell membrane permeability and integrity through multiple mechanisms, in addition to muscarinic receptor blocking effect of ATS. © 1993 Wiley-Liss, Inc.     

ARF suppresses hepatic vascular neoplasia in a carcinogen-exposed murine model

Hepatic haemangiosarcoma is a deadly malignancy whose aetiology remains poorly understood. Inactivation of the CDKN2A locus, which houses the ARF and p16(INK4a) tumour suppressor genes, is a common event in haemangiosarcoma patients, but the precise role of ARF in vascular tumourigenesis is unknown. To determine the extent to which ARF suppresses vascular neoplasia, we examined the incidence of hepatic vascular lesions in Arf-deficient mice exposed to the carcinogen urethane [intraperitoneal (i.p.), 1 mg/g]. Loss of Arf resulted in elevated morbidity and increased the incidence of both haemangiomas and incipient haemangiosarcomas. Suppression of vascular lesion development by ARF was heavily dependent on both Arf gene-dosage and the genetic strain of the mouse. Trp53-deficient mice also developed hepatic vascular lesions after exposure to urethane, suggesting that ARF signals through a p53-dependent pathway to inhibit the development of hepatic haemangiosarcoma. Our findings provide strong evidence that inactivation of Arf is a causative event in vascular neoplasia and suggest that the ARF pathway may be a novel molecular target for therapeutic intervention in haemangiosarcoma patients.     

Vasodilatory activity of novel carbamate derivatives of isatin

Isatin (1H-indole-2,3 dione) is an endogenous compound that may act as a physiological regulator of muscle contraction by reducing cGMP production by inhibition of guanylyl cyclase (GC) activity. Intracellular cGMP levels can regulate the contractile response of smooth muscle. Therefore, in the present study we investigated the effects of seven novel carbamate derivatives of isatin, namely C1-C7, on the contractility of aortic rings from Wistar rats. Carbamates C1 and C6 most effectively promoted endothelium-dependent relaxation of aortic rings pretreated with 10 micromol/L phenylephrine (PE) to induce contraction. The concentration of the C1 and C6 carbamates necessary to reduce PE-induced aortic contraction by 50% (IC(50)) was 5.6 +/- 1.0 and 48.4 +/- 3.4 micromol/L, respectively. Carbamate derivative-induced vasodilation required an intact endothelium, which is responsible for nitric oxide (NO) release. Pretreatment of rings with 100 micromol/L naloxone or 10 micromol/L atropine prevented the C1- and C6-mediated vascular relaxation, indicating that the vasodilatory activity was dependent on the activation of opioid or muscarinic receptors, respectively. The results of our studies provide insights into the role of novel carbamates in the regulation of vascular tone. Carbamates could stimulate NO synthesis, which induces vasodilation primarily by stimulation of GC and cGMP production. Taken together, our findings suggest that carbamate derivative-induced vasodilation may be considered an alternative treatment for primary and/or secondary hypertension.