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Biomedical subjects

J Kagawa

Publications and source records attributed to J Kagawa.

At least 73 records · Page 4Linked to original sources
PubMed1986

Phenotypic resemblance in birth weight between first cousins.

Birth weight data on 72,078 liveborn singletons representing 5981 paternal and 7036 maternal single first cousin kinships were assembled by computerized record linkage from all marriages and livebirths registered in Hawaii during a 38-year period from 1942 to 1979. These kinships represented incrosses of five selected racial groups. An additional 15,536 livebirths from 1134 paternal and 1679 maternal cousin kinships provided data on outcrossing between racial groups, and 28,952 livebirths from 2379 paternal and 3538 maternal cousin kinships provided data on both incrossing and outcrossing within kinships. Phenotypic resemblance in birth weight between single first cousins was estimated by the covariance and intraclass correlation. The covariances between maternal cousins were generally much higher than those between paternal cousins. Neither heterogeneity in maternal genotypes nor heterogeneity in newborn genotypes had any significant effect on the resemblance between first cousins. These observations have led to the conclusion that maternal influences of non-hereditary origin are of primary importance in determining birth weight in man. The observed non-zero correlation in several groups of paternal cousins was explained in part by the process of preferential selection of mates within and among racial groups by brothers, and probably by the similarity in some maternal characteristics associated with age at childbearing among their wives.

Asian People↗
PubMed1985

Evaluation of biological significance of nitrogen oxides exposure.

This paper attempts to assess health risks associated with nitrogen oxides (NOx) exposures. Experimental animal studies show that continuous or intermittent exposures to concentration of 0.04 to 0.5 ppm nitrogen dioxide (NO2) produce a number of pulmonary and systemic effects. Controlled human exposure studies show that short-term exposures to 0.3 to 0.5 ppm NO2 or 1.0 ppm nitric oxide produce bronchoconstriction and blood biochemical changes in some subjects. When we consider together both findings of the animal and human exposure studies, we may suggest with some reliability that the concentrations of NOx in ambient and indoor air pollutions may have adverse health effects on some subjects, and may partly contribute to the respiratory symptoms or illness and reduced pulmonary function observed in the epidemiological studies.

Animals↗
PubMed1984

Exposure-effect relationship of selected pulmonary function measurements in subjects exposed to ozone.

Healthy adult male volunteer subjects were exposed to 0.15, 0.3, 0.45 and 0.5 ppm ozone (O3) with and without intermittent light exercise. The results suggest that the subject's level of exercise during exposure is considerably related to the magnitude of changes in lung function and the occurrence rate of respiratory symptoms at any given O3 concentration, and that among healthy subjects there is a considerable range of reactivity to O3 exposure. A level of 0.15 ppm O3 with intermittent light exercise produced a significant decrease of specific airway conductance in most subjects and coughing during deep inspiration in five of 15 subjects, while a level of 0.5 ppm O3 produced fewer effects when the subject did not exercise. The nonsmoker is more reactive to O3 than the smoker. The subject's level of exercise during exposure and his smoking habit are two important factors in evaluating the exposure-effect relationship of O3.

Adult↗
PubMed1983

Respiratory effects of two-hour exposure with intermittent exercise to ozone, sulfur dioxide and nitrogen dioxide alone and in combination in normal subjects.

Seven adult male healthy volunteer subjects were exposed to 0.15 ppm each of O3, SO2 and NO2 alone and in combination, with intermittent light exercise for two hours. Three of the 7 subjects developed cough during deep inspiration and one subject had chest pain during exposure to O3 alone. Among the various indices of pulmonary function tests, specific airway conductane (Gaw/Vtg) was the most sensitive index to examine the changes produced by the exposure to O3 and other pollutants. Significant decrease of Gaw/Vtg in comparison with control measurements was observed in 6 of 7 subjects during exposure to O3 alone, and in all subjects during exposures to the mixture of O3 and other pollutants. However, no significant enhancement of effect was observed in the mixture of O3 and other pollutants, although a slightly greater decrease of Gaw/Vtg was observed for the mixture of O3 and other pollutants than for O3 alone.

Adult↗
PubMed1975

Effects of ozone and brief exercise on specific airway conductance in man.

Four normal male subjects were exposed to 0.9 ppm ozone with exercise for five minutes. Specific airway conductance (Gaw/Vtg) was increased by exercise and decreased by inhalation of ozone in most subjects, but these effects were small. Ozone inhalation with exercise resulted in a highly significant decrease of Gaw/Vtg. It would seem that a peak concentration of 0.9 ppm of ozone for five minutes produces adverse effects when the subject undertakes exxercise in it.

Airway Resistance↗
PubMed1975

Photochemical air pollution: its effects on respiratory function of elementary school children.

The effects of photochemical air pollution on respiratory function of Tokyo elementary school children were investigated. Nine types of environmental factors were continuously recorded. Seven categories of respiratory function tests were performed on 20 normal 11-year-old children once a week from June to December 1972, as a general rule. The correlation coefficients between respiratory function measurements and each of the environmental factors were calculated. The maximum expiratory flow rate (V max) showed high correlation with the largest number of environmental factors. Among environmental factors, temperature highly affected various respiratory function tests. The O3 was significantly associated with airway resistance (Raw) or specific airway conductance (Gaw/Vtg), NO or NO2 with V max, and temperature with Raw, Gaw/Vtg, and V max. Two subjects among all subjects were considered as the reactors to the environmental factors.

Air Pollutants↗