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Biomedical subjects

S Suna

Publications and source records attributed to S Suna.

17 recordsLinked to original sources
PubMed2000

Spermatogenic disturbance induced by di-(2-ethylhexyl) phthalate is significantly prevented by treatment with antioxidant vitamins in the rat.

Phthalate esters, now regarded as endocrine disruptors, are widely used in the plastics industry. In particular, di-(2-ethylhexyl) phthalate (DEHP) is produced in large quantities, and is used in blood storage bags, catheters and haemodialysis instruments. Previous studies have demonstrated that treatment of rats with DEHP induces testicular atrophy with liver enlargement, although the precise nature and mechanism of the action of DEHP on these organs remains unclear. In the present study, we produced an experimental model of DEHP-induced spermatogenic disturbance in rats by feeding them a DEHP-containing diet. Liver enlargement occurred in rats fed either a 1 or 2% DEHP-containing diet. However, testicular atrophy accompanied by aspermatogenesis was induced by feeding with the 2% but not with the 1% DEHP-containing diet. This suggests that the critical DEHP dose for gonadotoxicity is higher than that for hepatotoxicity. Using the 2% DEHP-dose, the effect of simultaneous administration of antioxidant vitamins (= vitamins C and E) was next examined. It was found that the vitamin supplementation significantly prevented the testicular injury. The results suggest that antioxidant vitamins can protect the testes from DEHP-toxicity.

Animals↗
PubMed1995

A study on urine cotinine for the evaluation of smoking cessation.

Two branch offices of enterprise T in the same city engaged in service and sales were selected at random for this study on the evaluation of smoking cessation education using the urine cotinine concentration (U-Cot) measured by ion pair reversed-phase high performance liquid chromatography (IP-R-HPLC). Branch A conducted a smoking cessation education program; branch B did not. By comparison of the results obtained from questionnaires and U-Cot analyses at both the offices, we investigated the validity of evaluation by U-Cot. The results were as follows: I. Smokers 1. At branch A, a self-reported 20-year-old female non-smoker was confirmed to smoke about 5 cigarettes per day by her high concentration (292.8) of U-Cot at pre-education. 2. At branch A, the self-reported average number of cigarettes smoked daily (ANCSD) at 6 months post-education showed a significant decrease in comparison with that at pre-education. 3. At branch A, U-Cot at post-education showed a significant decrease in comparison with those at 2 weeks, 2 months, and 6 months pre-education in descending order. 4. Two male subjects who were strongly suspected to have submitted a false number of cigarettes smoked prior to urine sampling (NCSPU)/ANCSD self-reports at 6 months post-education were confirmed to have done so by the U-Cot values at the fourth period, which were in excess of 500, and the discrepancy between the ratio ([value at post-education in 6 months] divided by [value at pre-education]) of U-Cot (1.52, 1.47, respectively) and that of NCSPU/ANCSD, (0.00)/0.00). 5. At branch A, discrepancies between the success rate of quitting smoking in self-reported NCSPU/ANCSD at 6 months (17.0%) and in U-Cot (12.2%) were observed. At branch B, no such discrepancies were observed. 6. At branch A, office workers at 6 months post-education who had, but not those who had not, previously considered the health damage caused by smoking showed a significant decrease in NCSPU/ANCSD, and also in U-Cot at 2 weeks, 2 months and 6 months post-education. At branch B, no such differences were observed. 7. At branch A, office workers at 6 months post-education who had previously considered quitting smoking showed a significant decrease in NCSPU/ANCSD, and also in U-Cot at 2 weeks, 2 months and 6 months post-education. Those who had not previously considered quitting showed a significant decrease in ANCSD, but not in NCSPU or U-Cot.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1994

[Chlordane accumulations in adipose tissue of mice chronically exposed to chlordanes in indoor air].

Chlordane concentrations were analyzed in the adipose tissue of mice after prolonged inhalation of low levels of chlordanes in indoor air. After inhalation of 4.22-11.36 micrograms/m3 chlordanes (total of 5 compounds) in air for 1-6 months, high levels of chlordanes (4.19-11.63 ppm, total of 5 compounds and 2 metabolites) were found in the adipose tissue. Transnanochlor, which accounted for only 14% of the total chlordane in the inhaled air, showed a high percentage (50%) in the adipose tissue, followed by 2 metabolites, i.e., oxychlordane (25%) and heptachlorepoxide (22%). Little transchlordane, cis-chlordane, or heptachlor, which accounted for high percentages of the total chlordane inhaled, was detected in the adipose tissue. A low level of cis-nonachlor was observed in the adipose tissue, and its percentage was similar to that in the air (2%). The level of chlordane exposure and the adipose tissue chlordane concentration was closely correlated (r = 0.9077, p < 0.01), showed a dose-effect relationship. These findings suggest that chlordanes such as trans-nonachlor, oxychlordane, and heptachlorepoxide may accumulate in the adipose tissue of people living in an environment containing even low levels of chlordanes and that there is a risk from indoor air contamination by chlordanes.

Adipose Tissue↗
PubMed1993

[Measurement of ethylene oxide at a medical sterilization site].

Although ethylene oxide gas is widely used as a sterilizing agent for medical instruments because of its disinfection property, the effects of its use in medical settings have not been clarified. In the present study, we measured the ethylene oxide gas concentration (EOGC) within a hospital sterilization unit and in the ambient air near the unit. Before the sterilizer was turned on (about 9:00), the ambient air EOGC was below the detection limit (0.1 ppm). When the door was opened to place the instruments in the sterilizer, the maximum EOGC near the door of the sterilizer was 1.71 ppm. Before the sterilizer door was opened, the residual EOGC within the sterilizer was 0.10-24.56 ppm. During the operation of the sterilizer (9:00-17:00), ethylene oxide gas could not be detected in the air near the unit. When the sterilizer door was opened at the end of the routine operation of the sterilizer (about 17:00), EOGC near the door was 2.10-2.73 ppm. After the door was closed, the ambient air EOGC level was 0.5-0.57 ppm. These findings indicate that the personnel near the unit were exposed to ethylene oxide gas for about 15 min during the transfer. However, no ethylene gas could be detected by the ethylene oxide gas monitor (3M Co., #3551). The finding that EOGC in sterilized medical instruments after 24 h of aeration was about 2 ppm also suggests that the personnel using these instruments were exposed to ethylene oxide gas.(ABSTRACT TRUNCATED AT 250 WORDS)

Air↗
PubMed1991

[Assessment of cadmium and lead released from cigarette smoke].

Cigarette smoke, which contains many harmful compounds, affects not only the smoker's health but also indoor air quality. To evaluate indoor air contamination by cadmium (Cd) and lead (Pb), we measured Cd and Pb contained in the mainstream and sidestream smoke exhaled by experimental smoking of Japanese cigarettes and also determined urinary and blood Cd and Pb levels in smokers and non-smokers and air Cd and Pb levels in smoky environments. 1. One cigarette of each of 7 Japanese brands contained about 1 microgram each of Cd and Pb, of which about 50 ng each was released to the mainstream and 250 ng of Cd and 50 ng of Pb to the sidestream by smoking. 2. The blood Cd level in the smokers was significantly higher than that in the non-smokers. The urinary Cd level in the smokers was slightly higher than that in the non-smokers. The blood Cd level was related to the number of cigarettes smoked daily. Blood and urinary Pb levels did not differ between the smokers and non-smokers, but the blood Pb level was also related to the number of cigarettes smoked daily. 3. The air Cd levels in smoky places such as the smoking car of the special express train, an office, and a pachinko parlor were markedly higher than that in outdoor air. The air Cd concentration was well correlated with the environmental tobacco smoke concentration. On the other hand, the air Pb level was slightly higher in the above smoky places than outdoors. The mean air Pb concentration was not correlated with the environmental tobacco smoke concentration but was higher at higher environmental tobacco smoke concentration in each place.

Adolescent↗
PubMed1990

[Variations in blood cholinesterase activity and exposure to chlorpyrifos in termite-control workers].

Chlorpyrifos, an organophosphate insecticide, has often been used as a termite-control agent since the advent of regulatory measures against the use of chlordanes in September 1986. A current concern is hazards such as organophosphorus poisoning among termite-control workers. In this study, the blood cholinesterase activity, the number of hours engaged in termite-control work, general conditions, and various test values were examined regularly in eight workers at a termite-control office. The results are summarized as follows. 1. The plasma cholinesterase level was within the normal range from October 1986 until April 1987 in all workers, but started decreasing after May following the initiation of the full-scale termite-control season. It remained lower than the normal range (0.6 pH) from June until August in five of the six termite-control workers. The lowest level observed during this period was less than 50% of the mean value for each worker prior to the busy season in the six termite-control workers and was less than 10% of the pre-season values in three of them. In two workers, engaged mainly in sales, the plasma cholinesterase activity remained higher than in termite-control workers throughout the season. The lowest level in this minimally-exposed group during this period was not less than 50% of the mean value for each worker before the busy season. With the arrival of the off season, the level began to recover and returned to normal in all workers in January 1988. 2. The red cell cholinesterase activity remained within the normal range throughout the observation period, but it was generally low during the busy season from June to September and relatively high during the off season from December 1987 to January 1988. On the average, the red cell cholinesterase activity during the season was about 30% lower than that in the off season. 3. No marked subjective or objective abnormalities were seen in the workers. The results of other tests were generally normal, although a slight decrease in the red cell and white cell counts as well as abnormalities in serum lipid and lipase were noted in some workers. Further observations are necessary. 4. A significant negative correlation was noted between the number of hours engaged in termite-control work and variations in the plasma cholinesterase activity.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1989

[The actual state of occupational exposure to chlorpyrifos of termite control workers].

Chlorpyrifos, an organophosphorus insecticide, has been used as a termite control agent since regulatory measures against the use of chlordane were taken in September, 1986. In this study the actual state of occupational exposure to chlorpyrifos of termite control workers was investigated. The findings obtained were as follows. The concentration of chlorpyrifos in the air (near the mouth) was about 10 times higher (1.7-2.3 mg/m3) under the floor than the threshold-limit value (0.2 mg/m3) proposed by the ACGIH and rose close to the threshold-limit value even above the floor. Regarding the performance of the absorption can of the mask, generally satisfactory results were obtained. The adhesion of this compound to the work outfit was conspicuous during the spraying work under the floor, and it was often noted on the right forearm (12 micrograms/cm2), on the left knee (10 micrograms/cm2), on the right knee (9 micrograms/cm2) and on the face (5 micrograms/cm2). The rate of this compound penetrating through the work outfit amounted to an average of 40 percent, making it clear that a considerable amount of the compound penetrated the work outfit. Furthermore, direct adhesion of the compound to the neck was considered. These results suggested the dermal-exposure to chlorpyrifos of termite control workers. This compound was detected, though the quantity was very small, in blood after work, which was definitely indicative of exposure at the time of termite control work. The plasma cholinesterase activity in the termite control workers was within the normal range before the busy termite control season but fell off markedly when the full-scale termite control season set in. It is suggested that a decrease in plasma cholinesterase activity occurs due to chlorpyrifos exposure.

Chlorpyrifos↗