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Biomedical subjects

H Kasuga

Publications and source records attributed to H Kasuga.

At least 73 records · Page 4Linked to original sources

The heterogeneity of human fibroblasts as determined from the effects of hydrocortisone on cell growth and specific dexamethasone binding.

To elucidate the heterogeneity of human fibroblasts from lung and skin, the effects of hydrocortisone on cell proliferation and the specific dexamethasone binding to cells were studied. Hydrocortisone at physiological concentrations stimulated the proliferation in three strains of human fetal lung fibroblasts and inhibited it in two strains. There are two kinds of fibroblasts in the human fetal lung in addition to the human skin fibroblasts reported previously. Dexamethasone-binding experiments showed that human fibroblasts may be classified into two groups with respect to the dissociation constant (Kd) of the binding reaction. The heterogeneity of human fibroblasts shown by Kd could not be correlated to classification on the basis of the effects of hydrocortisone on cell proliferation. The differences in Kd for the binding reactions suggest differences in donor tissues from which human fibroblasts are derived.

Cell Division↗

A review of urinary hydroxyproline as a biochemical marker on health effects of smoking and air pollution with nitrogen dioxide.

A series of epidemiologic studies on the health effects caused by smoking and air pollution with NO2 were carried out. Urinary hydroxyproline (HOP) which is excreted into the urine by catabolism of lung collagen was used as a biochemical marker. Urinary HOP of smokers increased dose-dependently with increasing numbers of cigarettes smoked and this result was accepted under blind conditions. Urinary HOP of nonsmokers also increased with increasing the amounts of involuntary smoking caused by smokers in their families although the increases in HOP by passive smoking were less than those by active smoking. Health effects caused by indoor air pollution with NO2 in winter and automobile exhaust in summer were also demonstrated using urinary HOP. The effects of cessation of smoking were followed up for 14 weeks by the decrease in urinary HOP. In practice, the HOP to creatinine ratio (HOP ratio) in random urine samples was used as representative of the 24-hour urine samples. Some confounding factors for urinary HOP were taken into consideration in these studies.

Air Pollution↗

Personal exposure to nitrogen dioxide and its relation to indoor and outdoor air quality.

An estimating equation of annual geometric average of personal NO2 exposure was proposed. The average could be calculated from three variables, that is, personal NO2 exposures in one winter and one summer month and ratio of winter period in a year. Ten housewives living in Suginami Ward, a residential area in Tokyo, were chosen as subjects of this study. They were asked to measure daily averages of the personal NO2 exposures with a filter badge. Measurements were performed on consecutive seven days in every month from January to December of 1982 for a total of 84 samples per person. Their activities, the amount of fuel consumption and other living conditions were recorded at the same time. Outdoor NO2 concentrations and maximum, minimum and average temperatures were also measured at the center of their living area. The personal NO2 exposure and its seasonal variation were found to depend mainly on the type of space heaters, frequency of ventilation fan usage in a kitchen, and the amount of fuel consumption.

Air Pollutants↗

A comparative study on the health effects of smoking and indoor air pollution in summer and winter.

This study was performed by a comparison between summer and winter for the purpose of demonstration the actual conditions of health effects of indoor air pollution with special reference to NO2 and smoking, on the subjects composed of 820 school children and their 546 mothers in the two areas with different ambient NO2 concentrations. In either case, examination was carried out with standardized questionnaire test for respiratory symptoms, personal NO2 exposure measurement using the filter badge by Yanagisawa, and analysis of urinary hydroxyproline and creatinine in two areas with different ambient NO2 levels. Personal NO2 exposure level in winter season was 2-3 times higher than that in summer, particularly NO2 level among residents living in homes with non-vented stove for space heating was substantially higher from those of residents with vented stove. Wives with vented stove had a moderate exposure level in winter season by the contribution of NO2 originated from the kitchen and poor ventilation rate. Since the hydroxyproline to creatinine ratio (HOP-ratio) of children increased more, their household location were nearer to any heavy traffic roads in summer, health effects from automobile exhaust were suggested only in summer season. In summer season, personal NO2 exposure level were almost the same with the ambient NO2 concentrations over both areas. These results suggest that indoor air pollution in winter season may be separated from outdoor air pollution. It was a matter of course that hydroxyproline to creatinine ratio in winter season was higher than that in summer, in any group and in any area, but the range of variation of hydroxyproline to creatinine ratio was smaller by far than that of personal NO2 exposure level. Judging from urinary hydroxyproline to creatinine ratio, health effects of active smoking and passive smoking increased with increasing the number of smoked, dose-dependently in any season. According to stepwise multiple regression analysis, hydroxyproline to creatinine ratio had significant relation to either NO2 and active or passive smoking, but personal NO2 exposure level had no relation to cigarette smoking. NO2 and cigarette smoke were seemed to make hydroxyproline to creatinine ratio increase, independently each other.

Air Pollution↗

[Bonded bridges].

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Adhesives↗

Relationship between housing environment and allergic symptoms of children using ATS-DLD questionnaires.

Using pupils in three areas with different environmental factors (Suginami-ku, Tokyo: Aikawa-machi, Kanagawa prefecture: and Shimizu-shi, Shizuoka prefecture) as subjects, respiratory symptoms and domestic environment were surveyed by meams of the American Thoratic Society-Division of Lung Disease (ATS-DLD) questionnaires together with measurement of total immunoglobulin E (IgE) by the radioimmunosorbent test (RIST) and specific mite and cedar IgE by the radioallergosorbent test (RAST), as well as the relationship between "allergic symptoms" as designated in the ATS-DLD questionnaire and housing structure. The following knowledge was obtained. According to the ATS-DLD standardized questionnaires for prevalence of respiratory symptoms and allergic symptoms, Aikawa showed a significantly low value of 8.5% (p less than 0.001) compared with 15.8% for Suginami and 15.7% for Shimizu, referring to allergic rhinitis only. The positive rate of 300 U/ml and over of total IgE was 55.5% in Suginami, 49.1% in Shimizu and 40.4% in Aikawa. Aikawa showed the lowest the positive rate of total IgE in allergic symptoms. The housing was classified into three types according to the original structure each of which had characteristic ventilation rates. The positive rates according to the housing structure showed no differences by areas for Type A (wooden house) with good ventilation, but for Types B (mortar frame house) and C (steel reinforced frame house) with airtight structures, the rates increased in the order of Aikawa less than Shimizu less than Suginami, and a significant difference was observed between Aikawa and Suginami (p less than 0.01). However, in the same area no difference was noted between Type A and Types B and C. No difference in the positive rate of allergic experiences by housing structure, was noted among areas and housing structures in the same area for the group not experiencing allergic symptoms (A. Inexp. Group), while no difference was noted for Type A but the rates were high in the order of 60.0% in Aikawa, 65.2% in Shimizu and 75.3% in Suginami for Types B and C in the group experiencing allergic symptoms (A. Exp. Group). Furthermore, in the same area when the Type A was compared with Types B and C, the latter showed a higher positive rate than the formar in all three areas, with a significant difference (p less than 0.05) noted in Suginami.

Air Pollutants↗

Accumulation of arsenic in blue-green alga, Phormidium sp.

The behavior of a blue-green alga, Phormidium sp., against inorganic arsenic dissolved in media was studied. The Phormidium sp. was shown to have capabilities of endurance against a high concentration stress of arsenic and of accumulation of arsenic. Studies on excretion of arsenic by the alga showed that there were two excretion modes, each of which had a characteristic rate constant and it could be attributed to two types of binding situations between arsenic and the tissues of the alga. The arsenate absorbed by the algae was readily reduced to arsenite within their tissues.

Arsenates↗

An improved method for analysis of urinary hydroxyproline by an automated analyzer.

An improved method of analysis has been devised for estimating the amount of hydroxyproline excreted into the urine. This study has been performed to overcome the difficulties accompaning mass-examinations which are indispensable in epidimiological studies. Urine samples are pretreated with a resin-charcoal mixture for elimination of interfering substances or color inhibitions, and the supernatant is treated by evaporation to avoid complications followed by pH adjustment. The residue is reconstituted with diluted HCL. After pretreatment, samples a analyzed with an automated analyzer. Linearity of standard calibration curve, and recovery and reproducibility of this assay are satisfactory. This simple procedure of analysis requires little time. This method is also useful for routine clinical examinations.

Autoanalysis↗

Epidemiological study on the hydroxyproline: creatinine ratio as an index of growth rate.

A number of studies has suggested that urinary hydroxyproline can be used as an index of collagen metabolism and urinary hydroxyproline excretion is closely related to growth hormone. This report is a cohort study to demonstrate the relationship between the urinary hydroxyproline: creatinine ratio and growth rate for four years. The pattern of increased urinary hydroxyproline: creatinine ratio in adolescence appeared to be closely ralated to the general pattern of growth rate measured in school children. In has been shown that the urinary hydroxyproline: creatinine ratio is the most suitable index of the growth rate.

Body Height↗

[Preparation of carbon fiber reinforced fluid type resin denture (author's transl)].

Transverse strength of cured fluid resins is weaker than that of the heat cured. We have studied to improve the mechanical strength of self-cured acrylic resin by application of carbon fibers as reinforcement and simple methods which must be acceptable for technicians are proposed. A cloth type carbon fiber was the best reinforcement among studied carbon fibers such as chopped or mat. The chopped fibers were difficult to mix homogeneously with fluid resins and effectiveness of the reinforcement was low. Breaking often occurred at the interface between the reinforcement and resin in the cases of mat which gave defects to the test specimens. To prepare reinforced denture, the cloth was trimmed on the master cast after removal of wax and the prepreg was formed with the alginate impression on the cast by Palapress and the cloth. Other steps were same as the usual fluid resin.

Carbon↗