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Biomedical subjects

M Takamatsu

Publications and source records attributed to M Takamatsu.

At least 73 records · Page 4Linked to original sources
PubMed1985

Surveys of workers occupationally exposed to PCBs and of yusho patients.

Surveys of workers occupationally exposed to polychlorinated biphenyls (PCBs) in the production of thread or of paint, and of yusho patients were carried out from 1973 to 1982. PCB concentrations in the plasma of the workers ranged from 2 to 521 ppb, and some showed higher PCB levels in the plasma than typical Japanese yusho patients. Gas chromatographic patterns of plasma PCBs of the workers with high PCB levels were shown to match the patterns of the PCBs to which they had been exposed in the workplace. Japanese yusho children showed remarkable decrease with time, but no such decrease was observed in the yusho adults and the workers. Polychlorinated quaterphenyls (PCQs) were detected in the blood of typical Japanese and Taiwanese yusho patients, but PCQ levels in the plasma of the workers were below the detection limit of 0.02 ppb. Clinical findings and subjective complaints of the workers were usually slight compared with typical yusho patients, though some of them had mild dermal manifestations and their PCB levels were suspected to be related to serum triglyceride values. On the basis of these results, we discussed the relationship between the health status of the subjects and their contamination with PCBs or related compounds.

Adult↗
PubMed1984

The ontogeny of cytosol and nuclear progestin receptors in male rat brain and its male-female differences.

The fetal and postnatal development of the progestin receptor systems in the intact male rat brain was investigated by means of the in vitro cytosol binding and the nuclear exchange assay using [3H]R5020 [( 17 alpha-methyl-3H]17 alpha, 21-dimethyl-19-nor-4, 9-pregnadiene-3,20-dione). The cortical cytosol receptors, first detectable at day 0, rapidly increased at day 7, reaching a maximum at day 10, then gradually declined thereafter. The receptors in the HPOA appeared clearly at day 1, increased during the first 10 days, then remained constant at days 14-21. The postnatal developmental patterns of cytosol brain progestin receptors in males were essentially similar to those in females, but there were some differences between both sexes. The male HPOA at days 10-14 contained more receptors than the female one. Nuclear progestin binding was low in the neonatal male brain at days 1-3. Despite the low level of serum progesterone, the cortical nuclear binding suddenly increased at days 7-10, then remained high at days 14-21. A similar, though less pronounced, pattern was seen in the HPOA. The male pattern of nuclear binding, thus, essentially resembled the female one. However, lower binding in the cortex and, possibly, HPOA was found in males than in females at days 10-21. After progesterone injection postnatal male rats accumulated a lower concentration of progestin receptors in the cortex and, possibly, HPOA than similarly-treated females. It is concluded from these results that progestin receptors in male rat brain appear immediately after birth and develop differentially in the cortex and HPOA. The sudden onset of increased nuclear translocation of endogenous progestin receptor complexes may occur in the brain at around days 7-10. There is a marked sex difference in the nuclear progestin receptor system in the postnatal brain, particularly the cortex. Moreover, the postnatal male brain has lower capacities of nuclear receptor translocation than does the female one. The progestin receptor system in the cortex and, possibly, HPOA of rats in the early postnatal life might be involved with some processes in the mechanism of sexual differentiation of the brain.

Animals↗
PubMed1984

PCBs in blood of workers exposed to PCBs and their health status.

Fact-finding surveys of workers occupationally exposed to polychlorinated biphenyls (PCBs) in the production of silk thread or of paint were carried out. Some of the workers showed higher PCB levels in the plasma than typical yusho patients. Gas chromatographic patterns of their PCBs were shown to match the pattern of the PCBs to which they had been exposed. Levels of polychlorinated quaterphenyls in their blood were lower than 0.02 ppb. Medical findings were slight compared with typical yusho patients. From these results, the differences in contamination with PCBs and relevant compounds and in health status between these workers and yusho patients are discussed.

Adult↗
PubMed1984

PCBs in blood of workers exposed to PCBs and their health status.

Fact-finding surveys of workers occupationally exposed to polychlorinated biphenyls (PCBs) in the production of silk thread or of paint were carried out. Some of the workers showed higher PCB levels in the plasma than typical yusho patients. Gas chromatographic patterns of their PCBs were shown to match the pattern of the PCBs to which they had been exposed. Levels of polychlorinated quaterphenyls in their blood were lower than 0.02 ppb. Medical findings were slight compared with typical yusho patients. From these results, the differences in contamination with PCBs and relevant compounds and in health status between these workers and yusho patients are discussed.

Adolescent↗
PubMed1984

Decreased progestin receptors in the cerebral cortex of hypothyroid postnatal rats.

The effects of neonatal hypothyroidism were examined on the concentrations of cytosol receptors for progestin and estrogen in the cytosols from 10-day old female and male rats. The concentration of cytosol progestin- and estrogen receptors in the 10-day old female and male rats with propylthiouracil-induced hypothyroidism was determined by multiconcentration saturation analysis. Neonatal hypothyroidism markedly depressed the level of progestin receptors in the cortex but not in the hypothalamus-preoptic area (HPOA). There were no differences in the concentration of estrogen receptors in the cortex and HPOA between the control and PTU rats. These results suggest that thyroid hormone may be one of the factors affecting the development of progestin receptors in the cortex. Its significance was discussed in relation to determination of the length of sexual differentiation of the rat brain.

Animals↗
PubMed1981

Augmented malondialdehyde production by platelets from patients with cerebrovascular disorders.

A basic study was conducted on the method for the determination of thiobarbituric acid-reactive substances (TBARS) produced by platelets. Some modifications were introduced which enabled a precise semimicrodetermination. The average values of platelet TBARS production in hypertensives and in patients with cerebral infarction were higher than that in healthy controls. Among patients with cerebral infarction, those with angiographically demonstrated obstruction of internal carotid or middle cerebral arteries showed an increased production as compared with non-obstructive cases, these results may suggest the important role of platelet arachidonate metabolism in obstructive cerebrovascular disorders.

Aged↗
PubMed1980

Low back pain related to bowing posture of greenhouse farmers.

Farming by means of greenhouses has spread in different parts of Japan during the past 20 years. Low back pain, an important health problem for farmers, affects those working inside a greenhouse as a result of their taking up particular postures. In order to analyze ergonomic problems of greenhouse farming relevant to low back pain, localized fatigue complaints and parts of the body where fatigue was felt during fruit picking were studied among 49 female farmers engaged in greenhouse strawberry culture and 53 female farmers engaged in greenhouse eggplant culture. Furthermore, the bowing posture for strawberry picking was compared with that of eggplant picking using newly devised posture-pattern recording equipment. More than 50% of strawberry or eggplant farmers complained of fatigue in the lower back and shoulders. The prevalence of low back pain was significantly higher among strawberry farmers than among eggplant farmers, probably due to the deep bowing posture of the farmer during picking work. The new posture-pattern recording equipment proved useful for investigating changes of work postures.

Adult↗