Determination of 1, 1-dichloro-l-nitroethane in air of workplaces by gas chromatography / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish a gas chromatography method for detecting the concentration of 1,1-dichloro-1-nitroethane in air of workplaces.</p><p><b>METHOD</b>1,1-dichloro-1-nitroethane in air of workplaces was collected by activated charcoal tube, absorbed using carbon disulfide and analyzed by Gas Chromatography (FID) with FFAP capillary column.</p><p><b>RESULTS</b>The linear rang of 1,1-dichloro-1-nitroethane in this method was 4.0-858.2 microg/ml, the linear regression formula was Y = 283X-1076, the correlation coefficient was 0.9999, the lowest detection concentration was 0.4 mg/m3 (3L sampling air), the relative standard deviation (RSD) was 1.8%-4.1%, the desorption efficiency was 88.5%-90.6%, the breakthrough volume was > 0.7 mg, the sampling efficiency was 100%, the samples could be kept at ambient temperature for at least 7 days.</p><p><b>CONCLUSION</b>The indicators of this method were conformed to the requirements of "Guide for establishing occupational health standards--Determination methods of air chemicals in workplace". This method could be used to detect 1,1-dichloro-1-nitroethane in air of workplaces.</p>

Determination of residual epoxyethane in medical instruments by headspace capillary gas chromatography / 中国医疗器械杂志

<p><b>OBJECTIVE</b>To establish a method of determining the residual epoxyethane in medical instruments.</p><p><b>METHOD</b>An HP-5 capillary column (30 m x 0.32 mm x 0.25 microm), an FID detecter and an oven were used in the determination. The oven temperature was kept at 120 degrees C for 8 minutes, the example inlet temperature was kept at 200 degrees C, while the detecter temperature was kept at 250 degrees C.</p><p><b>RESULT</b>The method has a linear range between 5.1920-51.920 microg, (r = 0.997, n = 6). The average rate of recovery of the injecter is 103.3%. The average rate of recovery of the infusion devices is 81.04%.</p><p><b>CONCLUSION</b>The method has been proved to be convenient, sensitive and accurate. It is suitable for the determination of residual organic solvents in medical instruments.</p>

Effect of Ethane 1,2-Dimethane Sulfonate(EDS) on the Testicular Expression of Steroidogenesis-related Genes and Epididymal Sperm Count in the Adult Rat / 대한남성과학회지

PURPOSE: Ethane 1,2-Dimethane sulfonate (EDS), an alkylating agent, has been widely used to create the testosterone withdrawal rat model. The present study was carried out to test the effect of EDS administration on the expression of steroidogenesis-related genes in the rat testis and on epididymal sperm counts. MATERIALS AND METHODS: Adult male Sprague-Dawley rats (300~350 g B.W.) were injected with a single dose of EDS (75 mg/kg, i.p.) and sacrificed on days 0, 7, 14, 21, 28, 35, 42, and 49. Tissue weights (testis, epididymis and seminal vesicle) were measured, and serum LH levels were determined by specific radioimmunoassay. The transcriptional activities of LH receptor (LH-R), 3beta-hydroxysteroid dehydrogenase (3beta-HSD), and steroidogenic acute regulatory protein (StAR) were evaluated by semi-quantitative RT-PCR. RESULTS: Weights of the reproductive and accessory organs declined progressively after the EDS treatment (weeks 1~3). After this, the decrease stopped, with a gradual return towards normal. Full recovery was observed in testis and seminal vesicle evaluations on weeks 5 and 6, respectively. Only 70% recovery was found in epididymis during weeks 5~7. A more dramatic drop was observed in caput epididymal sperm count, and the maximum recovery was 40% on week 7. Serum LH level increased significantly on week 2 after EDS treatment, then gradually decreased during weeks 3~5. The transcripts for the steroidogenesis-related genes in testis declined sharply during weeks 1~2, then returned to normal on week 4. CONCLUSIONS: Our results demonstrate that EDS might directly induce severe damage, such as tissue destruction and decreased sperm counts, in epididymis compared to those in testis and seminal vesicles. Changes in the activities of testicular steroidogenesis-related genes caused by abrupt death and repopulation of Leydig cells in EDS-treated rats were in good correlation with other parameters shown in this and previouslypublished data. Taken together, the EDS injection model might be useful to understand not only the mechanism of differentiation of testicular somatic and germ cells but also the function of the epididymis in the aging process.

Tetra chloroethane toxicity on the rat liver and lung with the evaluation of the protective role of the nutritional elements [zinc and silibinin]

Tetrachloroethane [TTCE] is one of the chlorinated hydrocarbons used as an industrial solvent. It is also claimed to be an environmental pollutant that may have multisystem detrimental effects. This study demonstrates some of the biochemical and histological toxic effects of TTCE on the rat liver, kidney and lung. It also estimates the effect of this substance on the DNA content of the cells. The study also evaluates and compares the protective role of the nutritional supplements zinc and silibinin on the observed toxic effects. 60 adult Sprague Dawly rats were used for the experiment divided equally into six groups: a negative control group, a group receiving TTCE, a group receiving zinc and a group receiving silibinin. In addition there were groups of combined treatment of TTCE plus zinc and TTCE plus silibinin. TTCE was given at a dose of 0.01ml/kg, zinc was given at a dose of 30mg/kg and silibinin was given at a dose of 200mg/kg. The duration of the experinent was 4 weeks then biochemical analysis of liver and kidney functions as well as zinc level estimation were performed. Histopathological examination of the liver and lung was done including the estimation of the content of the nuclear DNA. The study revealed the occurrence of elevation in the serum levels of liver enzymes AST and ALT as well as urea and creatinine levels in the group received TTCE. This was associated with a significant drop in zinc level. The liver showed marked dilatation of central vein and blood sinusoids, some liver cells revealed deeply acidophilic homogenous cytoplasm with pyknotic nuclei while other cells showed vacuolated cytoplasm. The lung showed histological changes in both conducting and respiratory protions. There was also a significant increase of the DNA content of the hepatocytes and pneumocytes in this group. Administration of zinc combined with TTCE showed a statistically significant limitation in the degree of toxicity of TTCE. This protective effect was found to be significantly less obvious for silibinin. Zinc plays its protective role via its antioxidant effect that antagonizes the oxidative stress induced by TTCE. The study recommends the use of extra doses of zinc especially in those who are exposed to TTCE in industrial fields

Oxygen free Radical Reactions by Various Partial Pressure of Oxygen in Rats intoxicated with Carbon Monoxide

Experiments, using CO intoxicated male Sprague-Dawley rats, were carried out (1) to see the change of the oxygen tree radical reaction according to partial pressure of oxygen, and (2) to assess the effectiveness of superoxide dismutase (SOD) activity, malondialdehyde (MDA), and ethane as a parameter of the reaction. Ethane was measured in exhaled breath anti SOD activity and MDA In brain tissue. Experimental group consist of (1) Control group (=breathing with air[ambient air]), (2) HBO group (=exposed to hyperbaric oxygen(HBO, 3ATA, l00%] after all breath), (3) CO-Air group (=exposed to CO [3,970 ppm] after air breath followed by air breath), (4) CO-HBO group (=exposed to CO after air breath followed by HBO treatment), and (5) CO group (=exposed to CO after air breath, only for SOD activity & MDA measuring). Amount of ethane exhaled during 30 minutes of HBO treatment after GO exposure was significantly greater than those of all the other groups (p-value= .002) , suggesting more oxygen free radical reaction is taken place in CO intoxicated rats treated with higher partial pressure of oxygen. The long-term follow-up studies are required to differentiate the adverse effects of HBO treatment from the sequelae of CO poisoning itself, and to develop the preventive measures for the adverse effect of HBO treatment. And there was no significnat difference among the five groups in SOD activity and MDA measuring (p-value>.05). This result may be accounted for the rapid recovery of SOD activity and the metabolic degradation and excretion of MDA in a short time. In conclusion, measurement of ethane in exhaled breath is more effective than those of SOD activity and MDA as a parameter to assess the oxygen free radical reaction produced by HBO treatment for CO poisoned rats as a whole

Açäo larvicida de extrato bruto etanólico de Magonia pubescens St.Hil. (tingui-do-cerrado), sobre o Aedes aegypti(Lin.) em laboratório / Larvicid action crude ethanol extract of Magonia pubescens St.Hil.(tingui-do-cerrado), on the Aedes aegypti(Lin.), dengue's main vector

Realizaram-se testes biológicos com extrato bruto etanólico (e.b.e.) de Magonia pubescens St. Hill., (tingui-do-cerrado)(Sapindaceae) para verificar a açäo larvicida sobre o Aedes aegypti(Lin.). Os extratos foram obtidos a partir de cada parte da planta: casca do caule, envoltório da semente e semente. Após ter sido coletado, o material foi dessecado em estufa de ar forçado a 40§C, moído, percolado em etanol por 10 dias, filtrado em papel filtro qualitativo, concentrado em evaporador rotativo e dessecado em pistola à vácuo. Após a obtençäo do e.b.e. de cada parte da planta, este foi dissolvido em água, em diferentes concentraçöes e testados com larvas de 4§ estádio de A.aegypti para determinar a DL50, que foi de 35, 55 e 150mg do e.b.e./100ml de água destilada, respectivamente, para semente, envoltório da semente e casca do caule. Cada experimento foi realizado com 20 frascos descartáveis, com capacidade para 30ml, com uma larva em cada um deles e observados por 24 horas. As larvas foram criadas em câmara biológica climatizada a 28ñ1§c, umidade relativa de 80ñ5(pôr cento) e fotofase de 12 horas. Os testes biológicos com os e.b.e. foram realizados em outra câmara, climatizada similarmente. Entre os experimentos realizados, os e.b.e. da semente e seu envoltório, mostraram-se mais eficientes larvicidas do que os e.b.e. da casca do caule

Synthesis and characterization of some [t] 1- [substituted amino or piperidino] -1-phenylethanes: novel bioisosteric relatives of pcp

The fact that phencyclidine [PCP]-receptors have been involved in the binding interactions with other hallucinogens, such as sigmaopiates, initiated the idea of synthesizing some novel bioisosteric relatives of PCP. Such compounds would act as potential blockers for central PCP-receptors, and thus might be utilized in the discouraging drug abusers or the therapeutic treatment of the hallucinogenic symptoms of such abused agents. The suggested compounds are 1-[substituted amino or piperidino]-1-phenylethane derivatives

Lipid Peroxidation in Vivo Monitored as Ethane Exhalation in Hyperoxia / 예방의학회지

In vivo ethane production in rats was used as an index of oxygen toxicity. The rats were allocated to four exposure conditions; hyperbaric oxygenation (HBO=5 ATA, 100% O2), normobaric oxygenation (NBO=1 ATA, 100% O2), hyperbaric aeration (HBA=5 ATA, 21% O2) and normobaric aeration (NBA=1 ATA, 21% O2). After 120 minutes of exposure, the rats exposed to high concentration and/or high pressure oxygen exhaled significantly larger amounts of ethane than those exposed to NBA, and the differences in ethane production between any two groups were statistically significant (p<0.01). This finding supports the hypothesis that hypothesis that hyperoxia increase oxygen free-radicals and the radicals produce ethane as a result of lipid peroxidation. It is notable that the ethane exhalation level of the HBA group was significantly higher than that of the NBO group. This difference could not be accounted for by the alveolar oxygen partial pressure difference between the two groups.