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Biomedical subjects

S Ishizu

Publications and source records attributed to S Ishizu.

At least 19 recordsLinked to original sources
PubMed1997

Elevated serum levels of pantropic p53 proteins in chromium workers.

OBJECTIVES: This study investigated the possibility of applying serum pantropic p53 proteins in molecular epidemiologic studies, as a biomarker of environmental carcinogenesis. The serum levels of pantropic p53 proteins were determined in workers with past exposure to hexavalent chromium compounds. METHODS: Thirty-one male workers occupationally exposed to hexavalent chromium compounds in the production of chromium compounds for 0 to 23 years served as the exposed group. The referents were 10 volunteers without work-related exposure to chemicals. In the determination of pantropic p53 proteins, commercially available kits for enzyme-linked immunosorbent assay were used which quantitatively detected both mutant and wild-type human p53 proteins. RESULTS: The serum level of pantropic p53 proteins was in the range of 116.4 to 1122.6 pg/ml for the exposed workers and of 117.4 to 305.8 pg/ml for the referents. Nineteen percent of the exposed workers had a high p53 protein level (6 out of 31) when compared with the referents. All but 1 of the 6 workers had been occupationally exposed to chromium compounds for more than 11 years. Two of the 3 workers with a past history of lung cancer also showed high levels. CONCLUSIONS: Our findings confirm that the application of p53 proteins as a biomarker of environmental carcinogenesis merits further exploration.

Adult↗
PubMed1995

N-acetyltransferase activity in the urine in Japanese subjects: comparison in healthy persons and bladder cancer patients.

The activity of urinary N-acetylamino-transferase was determined by high-performance liquid chromatographic assay of acetylisoniazid and isoniazid after administration of isoniazid to healthy Japanese male and bladder cancer patients in Japan. The healthy subjects were 47 college students and 44 company employees ranging from 18 to 64 years old (mean +/- SC = 34.5 +/- 13.7). The bladder cancer group consisted of 58 male and 13 female patients, ranging from 28 to 82 years old (mean +/- SD = 60.8 +/- 11.6), who were being treated at several hospitals. The slow phenotype, defined as an acetylation ratio (acetylisoniazid/isoniazid) of less than 2.0, was observed in 13 (14.3%) of the 91 healthy subjects, and in 20 (28.2%) of the 71 bladder cancer patients; the difference between the two groups is significant (p < 0.05). A histogram of the acetylation ratio values showed an overall leftward shift of the patient group, indicating low values of acetylation ratio in this group as a whole (p < 0.01).

Acetylation↗
PubMed1991

Symptoms among workers with long-term exposure to methyl bromide. An epidemiological study.

Symptoms as an important sign of the effects of methyl bromide were studied in 56 male workers (37 currently exposed and 19 previously exposed) in a methyl bromide factory. The workers were 18 to 62 yr of age (mean age: 41) and were exposed from 1 to 25 yr (mean: 7 yr). They were compared to 56 age-matched referents with a standardized questionnaire. The results of pairwise comparison of the symptoms of the age-matched pairs of exposed and referent subjects showed that the occurrence of dizziness, numbness, paresthesia and weakness of extremities, nightmares, fatigue and dry and scaly skin was statistically significantly higher among the workers than among the referents. When the symptoms during the work shift (acute symptoms) were compared, irritation symptoms such as itching, bullae or reddish swollen hands and runny noses with nasal irritation were reported significantly more often in the exposed groups. The correlation of the symptoms among the exposed workers suggested that chronic symptoms are closely related to acute irritation symptoms and exposure duration. The results suggest that symptom inquiry is useful for detecting the possible effects of exposure to methyl bromide.

Adult↗
PubMed1991

[Subjective symptoms and blood findings in painters exposed to organic solvents].

Subjective symptoms and blood findings were studied in 16 construction workers and 30 vehicle repairmen using organic solvent and compared to 30 workers who were not exposed to organic solvents. A statistically significant increase was observed in the prevalence of subjective symptoms, serum phospholipid, lipoprotein fraction and IgE in construction workers and vehicle repairmen. A statistically significant decrease in neutrophils function was observed in construction workers.

Adolescent↗
PubMed1990

Natural killer cell activity in workers exposed to benzidine and beta-naphthylamine.

To investigate the effects of benzidine (BZ) and beta-naphthylamine (BNA) on the immune system in man, the activity of natural killer (NK) cells as well as the relative number (percentage) of Leu 11a positive cells in peripheral blood lymphocytes were measured in 63 dyestuff workers exposed to BZ and BNA (aromatic amines, AA). The cytotoxic potential per NK cell (unit NK cell activity) was approximated by dividing the NK activity per fixed numbers of unseparated mononuclear cells by the percentage of Leu 11a positive lymphocytes that mediated NK activity. Thirty one of these workers had previously been treated for bladder cancer and then cured (ex-cancer AA workers) whereas the remaining 32 had not been diagnosed as having bladder cancer (non-cancer AA workers). There was no significant difference in the gross NK activity per unseparated peripheral mononuclear cells among ex-cancer AA workers, non-cancer AA workers, and the control group (p greater than 0.05). The relative number of Leu 11a positive cells, on the other hand, was significantly higher in AA workers than in the control group (p less than 0.01). The unit NK cell activity, as a result, was significantly more reduced in both ex-cancer and non-cancer AA workers than in the control group (p less than 0.05 and p less than 0.01, respectively). Between ex-cancer and non-cancer AA workers, no significant difference was observed in terms of unit NK cell activity. These results indicated that the function of NK cells per se was impaired in AA workers whereas the number of circulating NK cells was relatively increased.

2-Naphthylamine↗
PubMed1988

[Cases of severe methyl bromide poisoning residing above a warehouse].

Methyl bromide has been widely used in Japan to fumigate grains and wood. One death and 3 cases of hospitalization resulted from exposure to methyl bromide at place of residence. These 4 cases were not employed and were members of one family living above a warehouse, the ground level of this building was a warehouse where herbs were stored and the second floor was their living area. On the 13th of May 1978 at 7:00 p.m., the herbs were fumigated with methyl bromide gas. The fumigator used 15 kg of methyl bromide (2 cylinders), a quantity far greater than usual. It is assumed that the concentration in the warehouse was between 10,000-15,000 ppm. Early in the morning on the 16th of May (3 days later), one of the family members, a 12-year-old girl, developed severe convulsions, and later 2 others also had severe convulsions, while the other suffered from marked mental confusion. The serum or plasma bromide ion level ranged from 280 to 600 ppm. The results of the clinical laboratory test showed that GOT exceeded the normal level in 3 out of the 4 cases. Moreover, LDH activity was above the normal range in 3 cases and CPK activity was increased in all the cases.

Adult↗
PubMed1987

[A simple determination method of bromide ion in plasma of methyl bromide workers by head space gas chromatography].

An improved method for the simple determination of bromide ion in plasma is described. It was modified from the method by Kawai, Sugiyama et al. (1985). In the improved method, 200 microliters of plasma and 800 microliters of distilled water were placed in a reaction vial to which 100 microliters of dimethyl sulfate was added. The reaction vial was immediately sealed, placed in an incubator at 85 degrees C, and shaken for 10 min. At the end of the reaction, a gas-tight syringe was used to draw out the head space gas of 1 ml. The methyl bromide gas was then injected into a gas chromatograph and methyl bromide was determined with F.I.D. A good linear relationship was obtained between the peak area of methyl bromide and the concentration of bromide ion within the range of 0.5 to 500 ppm. Bromide ion in the range of 0.5 to 500 ppm in standard solution was added to the plasma samples. After 10 repeated measurements, the relative standard deviation was found to be in the range of 2.8-3.6% and recovery was over 96%. The analytical results of this method were compared with those obtained by spectrophotometry. The analytical results obtained by the two methods were in good agreement (r = 0.9669) in plasma samples of 10 methyl bromide workers. A study to determine bromide ion concentration in 39 methyl bromide workers was made and the results were compared with those observed in 100 workers (control group) not exposed to methyl bromide.(ABSTRACT TRUNCATED AT 250 WORDS)

Bromides↗
PubMed1985

Multiple primary cancers, with special reference to occupational exposure.

Multiple primary cancer (MPC) relating to occupational exposure was studied. The study consisted of a literature survey, survey of on-going research and our project on the frequency and nature of MPC in an occupational cohort of Japanese dyestuff workers followed from 1962 through 1983. From the review of the literature and on-going research there is little information on MPC and existing findings are mostly incomplete. However, a few occupational agents known to be carcinogenic to more than two organs, i.e. arsenic or radium, have been reported to cause MPC. In our follow-up of occupational bladder cancer cases, increased MPCs compared with a matched control group of nonoccupational cases were observed, but further investigation is necessary for a final conclusion. Finally, epidemiologic problems inherent to the study of MPC, including occupational studies, are discussed.

Coloring Agents↗
PubMed1980

Behavioural effects in rats following repeated exposure to methyl bromide.

Rats were exposed to methyl bromide (MB) at concentrations of 200 ppm and 300 ppm, 4 h per day, 5 times weekly, for 3 weeks. After the final exposure, behavioural tests for emotional response equilibrium function, the function of the peripheral nerve and the circadian rhythm of spontaneous activity were performed. Relatively prolonged dysfunction of the peripheral nerve as well as disturbance of the circadian rhythm of spontaneous activity were observed.

Animals↗
PubMed1980

Experimental studies on TDI dermatitis in mice.

Allergic contact dermatitis occurred with 2, 4-toluene diisocyanate (TDI) in BALB/c mice. The results were obtained by the measurement of the ear thickness after challenged to the ear with 1% TDI in olive oil in mice previously sensitized with 5% TDI. The ear swelling rate at 48 hr postchallenge in sensitized mice was more than twice of that in unsensitized mice. In BALB/c-nu/nu (nude) mice, delayed type hypersensitivity could not be induced even when a 30% TDI solution was applied. These results suggest that T cells may play an essential role in contact sensitivity to TDI in BALB/c mice.

Animals↗
PubMed1980

Cytotoxicity of methyl bromide: effect of methyl bromide on cultured mammalian cells.

Cytotoxicity of methyl bromide on cultured mammalian cells was examined. Acute toxic action was induced by methyl bromide itself and its cytotoxicity was reduced in the presence of glutathione. Its hydrolysis products or its reaction products with organic compounds in the medium was extremely low in toxicity. Although methyl bromide is known to be a methylating agent, morphological changes induced on HeLa cells were different from the changes characteristic of chemotherapeutic alkylating agents. Lethal concentration of methyl bromide on HeLa cells and primary cultured muscle, kidney and brain cells was similar (10 microgram/ml). In a detailed survey, however, there was a slight difference in the susceptibility among the cells from primary culture of brain.

Animals↗
PubMed1975

An epidemiological study of occupational bladder tumours in the dye industry of Japan.

This report studies 100 cases of occupational bladder cancer which were reported between 1949 and 1970 by large companies producing dye. It is estimated that in fact a great many more than 100 cases may have developed during the 56 years from 1914 to 1970, as this period corresponds with the beginning of dye production to the termination of benzidine and beta-naphthylamine manufacture in Japan. New cases of occupational bladder tumour should diminish significantly in the future in Japan on account of the prohibition of the production of beta-naphthylamine and benzidine. However, it is important to follow-up continuously workers who have been exposed to these amines. In Japan no cases of occupational bladder tumours from the rubber industry have been reported. It is emphasized that prospective epidemiological studies are required not only in the rubber industry but also in other industries where amines may constitute an occupational hazard.

2-Naphthylamine↗