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Biomedical subjects

C S Chung

Publications and source records attributed to C S Chung.

At least 127 records · Page 7Linked to original sources

Genetic and environmental determinants of periodontal disease.

Reanalysis of data on periodontal disease in 241 families [Chung et al, 1977b], based on an extended and more satisfactory path model [Rao et al, 1979], failed to detect significant heritability, and concluded in favor of cultural inheritance only, without maternal effects or intergenerational differences. The most parsimonious hypothesis yields a relative variance component of 0.338 +/- 0.024 due to indexed environment for both children and adults, the remainder (1.0--0.338 = 0.662) being due to residual nongenetic factors.

Culture↗

Dental plaque and dietary intakes in schoolchildren in Hawaii.

Plaque formation on the teeth as measured by the number of teeth with a heavy plaque accumulation was found to be influenced by diet. Accumulation of plaque was enhanced by the frequent consumption of food items such as sweet rolls, sweet breads, manapua, and poi. All of these are characterized by their sucrose content and stickiness. However, fruit drinks were shown to have a retarding effect on plaque growth. The information on the amount of plaque had little relationship with the dental caries status of the subjects, whereas it was significantly associated with periodontal health.

Adhesiveness↗

A genetic and epidemiologic study of periodontal disease in Hawaii. II. Genetic and environmental influence.

In order to determine the relative influence of genetic and environmental factors in periodontal disease, path analysis has been applied to 241 nuclear families. Common family environment was represented by an index. The data failed to detect significant heritability, and common family environment proved to be a major determinant in the variation of periodontal health.

Adolescent↗

Do American born Japanese children still grow faster than native Japanese?

Growth patterns of Japanese schoolchildren in Hawaii, composed of 2,954 boys and 3,213 girls aged between 11 and 17, were compared with those comparable groups of Japanese schoolchildren in Japan based on the data published by the Japanese Ministry of Education. Growth characteristics studied were height, weight, and relative weight index, weight/(height). The Hawaii-Japanese boys were taller at early ages but the difference disappeared by age 16. Native Japanese girls were shorter than Hawaii-Japanese until age 13, but they overtook the latter by age 14, exceeding them in height after age 15. A similar pattern was found in weights of girls but the Hawaii-Japanese boys remained consistently heavier by 5.0 to 9.0 kg than native Japanese. The relative weight measure indicated that the Hawaii boys were more "obese" than native Japanese boys for the growth period studied; whereas the same tendency was maintained until age 15 in girls. These observations indicate a marked degree of convergence of the patterns of physical growth of the two populations, whose differences were unmistakably in favor of American born children in earlier studies. It is concluded that the convergence is due largely to the improved environmental conditions in Japan in recent years.

Adolescent↗

Diabetes mellitus: discrimination between single locus and multifactorial models of inheritance.

Family data from 6,559 diabetic propositi were analyzed using the method of complex segregation analysis in an attempt to discriminate the two models of two-allele single-locus inheritance and multifactorial inheritance for early, middle, and late onset diabetes. The three parameters in the single locus model were: degree of dominance, penetrance, and proportion of phenocopies. In early onset diabetes, the heritability estimated from the multifactorial model was so high as to inidcate major gene action. In middle and late onset diabetes, best fitting single-locus models were found to explain the data as well as the multifactorial model.

Adolescent↗

Factors affecting risks of congenital malformations. I. Analysis of epidemiologic factors in congenital malformations. Report from the Collaborative Perinatal Project.

An analysis was made of over 30 demographic, biologic and medical variables in relation to risks of congenital malformations which occurred in the Collaborative Perinatal Project. The study population consisted of 46,689 single and multiple live births and fetal deaths about whom complete information was available on all study variables. Included in the analysis were 5 general malformation categories, 27 specific major, and 7 specific minor malformations. Several new associations were detected between epidemiologic factors and risks of specific malformations while other previously reported associations were confirmed by the present investigation. The analysis of general categories of malformations showed that multiple births had a higher frequency of major malformations than single births; whenever sex differences in incidence were noted, males, with few exceptions, had an excess of malformations over females; and maternal diabetes during pregnancy was associated with increased risk of major malformations in the fetus. Among specific findings of possible etiologic significance were that the risk for microcephaly was associated with infrequent prenatal visits and the presence of maternal hyperthyroidism; and unusually low weight gain and infrequent prenatal visits were associated with increased risk for lung hypoplasia. There was no significant effect of inbreeding of the fetus or mother on the risks of general or specific types of malformations. Anencephaly was more frequent among white than among Negro infants, whereas no difference in incidence was noted in spina bifida between the two racial groups. This finding points to an inconsistency in the hypothesis of common etiology for these malformations. Whites were also found to have significantly higher incidences over Negroes of pyloric stenosis, congenital dislocation of the hip, micrognathia, and pectus excavatum, while Negroes have higher incidences of metatarsus varus and inguinal hernia.

Cataract↗

Factors affecting risks of congenital malformations. II. Effect of maternal diabetes on congenital malformations.

The effect of maternal diabetes on the risk of congenital malformations was investigated in 23,695 pregnancies of white mothers, inclucing 339 patients of the Joslin Clinic, and in 24,742 pregnancies of Negro mothers, drawn from the prospective Collaborative Perinatal Project. Of these, 372 mothers had gestational diabetes and 567 had overt diabetes (before and during pregnancy). Pregnancy outcomes studied included stillbirths and live births. Among core women (excluding the Joslin Clinic cases), the frequencies of diabetic pregnancies were 1.31% and 1.18% for white and Negro mothers, respectively; in both groups, approximately two thirds of these pregnancies had gestational diabetes. There was no increase in malformation risk in the pregnancies of mothers with gestational diabetes over that of nondiabetic mothers in either racial group. However, the risk of malformation for white mothers with overt diabetes was double that of nondiabetic mothers for both major and minor categories of malformations. The incidences of major and minor types of malformations in the pregnancies of white mothers with overt diabetes were 17.94% and 10.94%, respectively, compared to the corresponding incidences of 8.34% and 6.25% for the white nondiabetic group. In Negro mothers with overt diabetes, a smaller increase of risk was seen only in major malformations; the incidences were 13.64% and 8.45% for the diabetic and nondiabetic groups, respectively. The increased risks for malformations were distributed generally throughout the organ systems. Multiple malformations occurred more frequently in the overt diabetic than in the nondiabetic group, suggesting that maternal diabetes must act adversely an an early stage of fetal development. Two cases with the caudal regression syndrome were observed in children of diabetic mothers, whereas none was found among births from nondiabetic mothers. Insulin (or analog) therapy of diabetes neither decreased nor increased the risk of malformation in the fetus. However, duration of diabetes had a significant effect on the malformation risk: the longer the mother had the disease, the higher was the incidence of malformations in the fetus. Paternal diabetes did not contribute to increase in risk. These observations suggest that maternal diabetes per se, through its adverse effects on maternal metabolism, is the responsible factor for the increase of malformations in the offspring.

Central Nervous System↗