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.
Animals ; Ethane* ; Exhalation* ; Hyperbaric Oxygenation ; Hyperoxia* ; Lipid Peroxidation* ; Oxygen ; Partial Pressure ; Rats

OBJECTIVETo establish a method of determining the residual epoxyethane in medical instruments.

METHODAn 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.

RESULTThe 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%.

CONCLUSIONThe method has been proved to be convenient, sensitive and accurate. It is suitable for the determination of residual organic solvents in medical instruments.

Chromatography, Gas ; methods ; Disposable Equipment ; Epoxy Compounds ; analysis ; Ethane ; analysis ; Solvents ; analysis

Air ; analysis ; Air Pollutants, Occupational ; analysis ; Ethane ; analogs & derivatives ; analysis ; Nitroparaffins ; analysis ; Uncertainty ; Workplace

OBJECTIVETo establish a gas chromatography method for detecting the concentration of 1,1-dichloro-1-nitroethane in air of workplaces.

METHOD1,1-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.

RESULTSThe 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.

CONCLUSIONThe 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.

Air Pollutants, Occupational ; analysis ; Chromatography, Gas ; methods ; Ethane ; analogs & derivatives ; analysis ; Nitroparaffins ; analysis ; Workplace

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
Animals ; Brain ; Carbon Monoxide* ; Carbon* ; Ethane ; Follow-Up Studies ; Humans ; Male ; Malondialdehyde ; Oxygen* ; Partial Pressure* ; Poisoning ; Rats* ; Rats, Sprague-Dawley ; Superoxide Dismutase

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.
Adult* ; Aging ; Animals ; Epididymis ; Ethane* ; Germ Cells ; Humans ; Leydig Cells ; Male ; Models, Animal ; Oxidoreductases ; Radioimmunoassay ; Rats* ; Rats, Sprague-Dawley ; Receptors, LH ; Seminal Vesicles ; Sperm Count* ; Spermatozoa* ; Testis ; Testosterone ; Weights and Measures