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Biomedical subjects

C Jin

Publications and source records attributed to C Jin.

At least 181 records · Page 10Linked to original sources
PubMed1991

Subjective symptom increase among dry-cleaning workers exposed to tetrachloroethylene vapor.

Subjective symptoms, hematology, serum biochemistry and other clinical signs were investigated in 56 dry-cleaning workers exposed to tetrachloroethylene at 20 ppm (as a geometric mean of 8-hr time-weighted average), and the results were compared with the findings in 69 non-exposed controls from the same factories. There were exposure-related increases in the prevalence of subjective symptoms during the work as well as in the past 3 month period, whereas there was no significant changes in hematology. Effects of the exposure on liver and kidney functions were also negative as judged by emission enzyme activities, BUN and creatinine in the serum.

Adolescent↗
PubMed1991

[Effect of Astragalus membranaceus on erythrocyte sodium content and sodium transport in the coronary heart disease].

The purpose of this study was to investigate the effect of Astragalus membranaceus (AM) on erythrocyte sodium content and sodium transport in the coronary heart disease(CHD). 67 cases of CHD was randomly divided into treatment group (TG) and control group (CG), TG (45 cases) were treated with AM intravenous 24 g/d infused into 5% glucose 250 ml, CG (22 cases) with 5% glucose 250 ml. After a curable stage of 14 days, results showed that the erythrocyte sodium content was markedly decreased and the sodium pump activity was significantly increased (P less than 0.01 respectively) in TG; but no significant difference in membrane permeability to sodium was observed. There were no difference in erythrocyte sodium content and sodium transport in CG. It was suggested that AM had the effects to increase erythrocyte activity of sodium pump.

Adult↗
PubMed1991

Visual rehabilitation in low vision patients with age-related macular degeneration.

Using optical visual aids, visual rehabilitation was performed in 14 low vision patients (25 eyes) with age-related macular degeneration. With distance aids, visual acuity improvement appeared in 24 eyes (95%) out of the 25 eyes. Twelve eyes (48%) obtained a visual acuity equal to or better than 0.4. With near visual aids, near acuity of all eyes (100%) was improved. Thirteen eyes (52%) got the near vision equal to or better than 0.5. Ten patients could read No. 5 Chinese Reading Card. The reading success rate was 71.4%. The results suggest that application of visual aids is an effective method to improve the distant and near visual acuity of low vision patients with AMD.

Aged↗
PubMed1991

[Visual rehabilitation in low vision patients with aging macular degeneration].

Using optical visual aids, visual rehabilitation were performed in 14 cases (25 eye) of low vision patients with aging macular unity of all eyes (100%) was improved. Thirteen eyes (52%) got the near vision equal to or better than 0.5. Ten patients could read No. 5 Chinese Reading Card. The reading success rate was 71.4%. The results suggest that application of visual aids is an effective method to improve the distance and near visual acuity of low vision patients with AMD.

Age Factors↗
PubMed1990

Sister chromatid exchanges in peripheral lymphocytes of workers exposed to benzene, trichloroethylene, or tetrachloroethylene, with reference to smoking habits.

The frequencies of sister chromatid exchanges (SCE) were studied in peripheral lymphocytes from four groups of solvent workers, i.e. 36 nonsmoking women exposed to benzene at about 50 ppm on the average, 38 men and women (male smokers and nonsmokers, and female nonsmokers) exposed to trichloroethylene (TRI) at 7 ppm, 27 men and women (both smokers and non-smokers) with tetrachloroethylene (TETRA) exposure, and 19 workers (both smokers and nonsmokers in men, and nonsmokers in women) exposed to a mixture of TRI (at 8 ppm) and TETRA (at 17 ppm) (TRI + TETRA). The results were compared with the findings in control subjects matched by age, sex, smoking habits and place of residence. No significant increase in SCE frequencies was observed in association with exposure to benzene, TRI, TETRA or TRI + TETRA. The SCE frequency was, however, significantly higher in the TRI-, TETRA- or TRI + TETRA-exposed smoking men than in the concurrent nonsmoking controls of the same sex. Possible synergism between solvent exposure and smoking is discussed.

Adult↗
PubMed1990

Blood lead levels of Beijing (China) citizens.

Lead levels were determined in 856 blood samples obtained from Beijing citizens who were either factory workers or clerks with no known occupational exposure to heavy metals including lead. Additional analyses were conducted on 74 samples from factory workers in the small city of Jinxi, China. The geometric mean blood lead level (Pb-B) among the general Beijing population 99.2 and 76.1 micrograms 1-1 for non-drinking and non-smoking men and women, respectively, with a statistically significant difference between the two sexes. The effect of drinking was not detectable, whereas that of smoking was suggested, but not conclusive. The Pb-B levels among Jinxi workers did not differ from the levels among Beijing citizens. The Pb-B for inhabitants of Beijing was similar to the levels of inhabitants of a medium-sized city, Hefei, and lower than the values for residents of two heavily industrialized large cities, Shanghai and Shenyang. The values for Chinese citizens appear to be higher than those for Japanese and Korean farmers, but the possibility of urban-rural differences remains to be examined.

Adolescent↗
PubMed1990

[Studies on left ventricular performances pre- and post-percutaneous balloon valvuloplasty in 57 cases].

The left ventricular performances (LVP), assessed by two dimensional echocardiography (2 DE) pre- and post-percutaneous balloon mitral valvuloplasty, showed a good linear correlation with those by angiography, the correlative coefficients being 0.94 (left ventricular volume), 0.93 (ejection fraction) and 0.90 (stroke volume), respectively. The results showed that 2 DE may be used in follow-up study of left ventricular performances instead of angiography. Accordingly, it was found that the short-term (6-10 months) effect in LVP of 57 cases post-PBMV assessed by 2 DE in comparison with that pre-PBMV was statistically very significant (t = 3.73-12.92, P less than 0.001); the long-term (12-42 months) effect of 88 cases post-PBMV evaluated by 2 DE compared with that pre-PBMV was statistically very significant (t = -3.73-10.46, P less than 0.001); all these showed that both the short-term and long-term cardiac functions post-PBMV had markedly improved. However, there was a significant difference in statistics (t = 2.41-3.14, P less than 0.05-0.001) between the short-term and long-term cavity area) and radionuclide angiography both during early diastole (r = 0.94) and atrial systole (r = 0.90). The above results were better than those obtained from pulsed Doppler (E area/Total, A area/Total) and radionuclide angiography: during early diastole (r = 0.78) and atrial systole (r = 0.76). Color Doppler can be used as a new method for assessing the pattern of left ventricular filling.

Adult↗
PubMed1989

Relationship between vapor exposure and urinary metabolite excretion among workers exposed to trichloroethylene.

The exposure-excretion relationship was investigated in 140 trichloroethylene (TRI)-exposed workers and 114 nonexposed controls. The time-weighted average intensity of exposure to TRI during the shift as measured by the diffusive sampling method was compared with metabolite levels in the urine collected at the end of the shift in the second half of a working week, when the urinary metabolite levels are expected to reach a maximum. The TRI levels in breathing zone air of the exposed workers were mostly below 50 ppm. The urinary metabolite levels (i.e., total trichloro-compounds, trichloroethanol, and trichloroacetic acid) increased as a linear function of the TRI exposure. The relationship between the two exposure indicators was statistically significant in men, women, and both combined. The cross-sectional balance study at the end of the shift revealed that about 4% of TRI absorbed will be excreted at the end of the shift, in agreement with the long biological half-life of this chlorinated hydrocarbon solvent. A possible ethnic difference in the metabolism of TRI is discussed.

China↗
PubMed1989

Dose-excretion relationship in tetrachloroethylene-exposed workers and the effect of tetrachloroethylene co-exposure on trichloroethylene metabolism.

Personal monitoring of 8-hour time-weighted average intensity of exposure with diffuse samplers and analysis of shift-end urine for total trichloro-compounds (TTC) and other metabolites were conducted in two groups of workers in China, one (121 subjects) exposed to tetrachloroethylene (TETRA) alone, and the other (38 subjects) exposed to a mixture of TETRA and trichloroethylene (TRI). Urinalysis was also performed on samples from 103 non-exposed controls. A linear exposure-excretion relationship could be observed in both groups of workers. Comparison of these results with those of Japanese TETRA-workers suggested the presence of ethnic difference in TETRA metabolism. Urinary metabolite levels were markedly lower in the mixed (TETRA + TRI) exposure group as compared to previous findings in a group exposed to TRI alone. The observation indicates that metabolism of TRI is suppressed by the co-exposure to TETRA in humans.

Air Pollutants, Occupational↗
PubMed1989

Blood cadmium levels in the populations of 3 Chinese cities.

Blood samples were collected from male and female factory workers aged greater than or equal to 16 years (with no occupational exposure to metals including cadmium) in the 3 cities of Hefei (323 subjects), Shenyang (78 subjects), and Jinxi (137 subjects) in China from 1985 to 1987. The samples were analyzed for cadmium in a single laboratory by automated flameless atomic absorption spectrophotometry under strict quality control. The effect of smoking was evident in Hefei, Shenyang and Jinxi, while the effect of aging was not apparent. There were no sex or regional differences in blood cadmium levels in non-smokers in the 3 cities (e.g., 1.2, 1.3 and 1.4 micrograms/l as geometric means in non-smoking women in Hefei, Shenyang and Jinxi, respectively). There was general agreement in blood cadmium levels between the present results and the values reported in the literature, although the latter values were generally based on small study populations.

Adult↗
PubMed1989

Urinary t,t-muconic acid as an indicator of exposure to benzene.

A method for rapidly determining t,t-muconic acid (MA) by high performance liquid chromatography was developed and successfully applied to urine samples from 152 workers exposed to benzene (64 men, 88 women) and 213 non-exposed controls (113 men, 100 women). The MA concentrations in urine correlated linearly with time weighted average benzene concentrations in the breath zone air of workers. A cross sectional balance study showed that about 2% of benzene inhaled is excreted into the urine as MA. The MA concentrations in the urine of the non-exposed was below the detection limit (less than 0.1 mg/l) in most cases, and the 95% lower confidence limit of MA for those exposed to benzene at 5 ppm (5.0 mg/l as a non-corrected value) was higher than the 97.5%-tile values for the non-exposed (1.4 mg/l). In practice, it was possible to separate those exposed to 6-7 ppm benzene from the non-exposed by means of urine analysis for MA. The urinary MA concentration was suppressed by coexposure to toluene.

Air Pollutants, Occupational↗
PubMed1989

Excretion of 1,2,4-benzenetriol in the urine of workers exposed to benzene.

Urine samples were collected from 152 workers (64 men, 88 women) who had been exposed to benzene, 53 workers (men only) exposed to a mixture of benzene and toluene, and 213 non-exposed controls (113 men, 100 women). The samples were analysed for 1,2,4-benzentriol (a minor metabolite of benzene) by high performance liquid chromatography. The time weighted average solvent exposure of each worker was monitored by diffusive sampling technique. The urinary concentration of 1,2,4-benzentriol related linearly to the intensity of exposure to benzene both in men and women among workers exposed to benzene, and was suppressed by toluene co-exposure among male workers exposed to a mixture of benzene and toluene. A cross sectional balance study in men at the end of the shift of a workday showed that only 0.47% of benzene absorbed will be excreted into urine as 1,2,4-benzenetriol, in close agreement with previous results in rabbits fed benzene. The concentration of 1,2,4-benzenetriol in urine was more closely related to the concentration of quinol than that of catechol. The fact that phenol and quinol, but not catechol, are precursors of 1,2,4-benzentriol in urine was further confirmed by the intraperitoneal injection of the three phenolic compounds to rats followed by urine analysis for 1,2,4-benzenetriol.

Animals↗
PubMed1989

A retrospective cohort study of leukemia and other cancers in benzene workers.

A retrospective cohort study was carried out in 1982-1983 among 28,460 benzene-exposed workers (15,643 males, 12,817 females) from 233 factories and 28,257 control workers (16,621 males, 12,366 females) from 83 factories in 12 large cities in China. All-cause mortality was significantly higher among the exposed (265.46/100,000 person-years) than among the unexposed (139.06/100,000 person-years), as was mortality from all malignant neoplasms (123.21/100,000 versus 54.7/100,000, respectively). For certain cancers, increased mortality was noted among benzene-exposed males in comparison with that among unexposed males; the standardized mortality ratios (SMR) were elevated for leukemia (SMR = 5.74), lung cancer (SMR = 2.31), primary hepatocarcinoma (SMR = 1.12), and stomach cancer (SMR = 1.22). For females only leukemia occurred in excess among the exposed. Risk of leukemia rose as duration to exposure to benzene increased up to 15 years, and then declined with additional years of exposure. Leukemia occurred among some workers with as little as 6 to 10 ppm average exposure and 50 ppm-years (or possibly less) cumulative lifetime exposure (based on all available measurements for the exposed work units). Among the 30 leukemia cases identified in the exposed cohort, the proportion of subjects with acute lymphocytic leukemia was substantially lower and the proportion with acute nonlymphocytic leukemias was higher than in the general population. During 1972 to 1981, the annual incidence of leukemia ranged from 5.83 to 28.33 per 100,000 with higher rates occurring in the interval 1977 to 1981 than in the earlier years of the study period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Blood lead levels of the general populations of three Chinese cities.

Blood samples were obtained from 537 adults (age greater than or equal to 16 years) living in three cities in China; in Hefei in 1985, and in Shenyang and Jinxi in 1987. The samples were subjected to blood lead (Pb-B) analyses. The subjects were factory workers either in solvent-synthesizing or solvent application plants with no known exposure to metals (including lead). Their smoking and drinking habits were confirmed in medical interviews. Blood lead was significantly higher in smokers than in non-smokers, although no dose-dependency was observed. The Pb-B values in non-smokers were log-normally distributed. The Pb-B among non-smokers was significantly higher in men [104.0 micrograms l-1 (1.428) 87] [geometric mean (geometric standard deviation) number of determinations] than in women [75.5 micrograms l-1 (1.358) 225] when the data from the three cities were combined. There was a significant difference in the Pb-B levels of non-smoking men in the three cities studied, suggesting that regional food habits should be considered as a possible contributory factor of a non-occupational nature. The present findings are compared with observations from Korea and Japan from the viewpoint of environmental health.

China↗
PubMed1988

Mutual metabolic suppression between benzene and toluene in man.

The exposure intensity during a shift and the metabolite levels in the shift-end urine were examined in male workers exposed to either benzene (65 subjects; the benzene group), toluene (35 subjects; the toluene group), or a mixture of both (55 subjects; the mixture group). In addition, 35 non-exposed male workers (the control group) were similarly examined for urinary metabolites to define background levels. A linear relationship was established between the intensity of solvent exposure and the corresponding urinary metabolite levels (i.e. phenol, catechol and quinol from benzene, and hippuric acid and o-cresol from toluene) in each case when one of the three exposed groups was combined with the control group for calculation. Comparison of regression lines in combination with regression analysis disclosed that urinary levels of phenol and quinol (but not catechol) were lower in the mixture group than in the benzene group when the intensities of exposure to benzene were comparable, indicating that the biotransformation of benzene to phenolic compounds (excluding catechol) in man is suppressed by co-exposure to toluene. Conversely, metabolism of toluene to hippuric acid was suppressed by benzene co-exposure. Conversion of toluene to o-cresol was also reduced by benzene, but to a lesser extent. The significance of the present findings on the mutual suppression of metabolism between benzene and toluene is discussed in relation to solvent toxicology and biological monitoring of exposure to the solvents.

Air Pollutants, Occupational↗
PubMed1988

Determination of catechol and quinol in the urine of workers exposed to benzene.

Time weighted average concentrations of benzene in breathing zone air (measured by diffusive sampling coupled with FID gas chromatography) and concentrations of catechol and quinol in the urine (collected at about 1500 in the second half of a working week and analysed by high performance liquid chromatography) were compared in 152 workers who were exposed to benzene (64 men, 88 women). The concentration of urinary metabolites was also determined in 131 non-exposed subjects (43 men, 88 women). There was a linear relation between the benzene concentrations in the breathing zone and the urinary concentrations of catechol and quinol (with or without correction for urine density) in both sexes. Neither catechol nor quinol concentration was able to separate those exposed to benzene at 10 ppm from those without exposure. The data indicated that when workers were exposed to benzene at 100 ppm about 25% of benzene absorbed was excreted into the urine as phenolic metabolites, of which 13.2%, 1.6%, and 10.2% are phenol, catechol, and quinol, respectively.

Benzene↗
PubMed1988

Increased subjective symptom prevalence among workers exposed to trichloroethylene at sub-OEL levels.

Over 100 workers exposed to trichloroethylene (TRI) mostly at less than 50 ppm during the production or vapor degreasing operation and about an equal number of the non-exposed control workers were examined for subjective symptoms, hematology, serum biochemistry, and sugar, protein and occult blood in urine. Essentially all the clinico-laboratory tests stayed normal, and there was no significant differences in the findings between the exposed and the controls. Thus, no clinically significant effects of TRI exposure were found in the blood and liver functions among the exposed workers as compared with the controls. The prevalence of the subjective symptoms was, however, significantly higher in the exposed group than in the controls, and dose-response relationship could be established in some selected symptoms such as nausea, heavy feeling in the head, forgetfulness, tremor in extremities, cramp in extremities and dry mouth, although the exposure was low. The findings warrant further attention to the effects of TRI especially on the central nervous system at the concentration lower than e.g., 50 ppm.

Adult↗