PubMed Health⌕ Search

Biomedical subjects

W H James

Publications and source records attributed to W H James.

At least 55 records · Page 3Linked to original sources
PubMed2000

Are oral clefts a consequence of maternal hormone imbalance? evidence from the sex ratios of sibs of probands.

BACKGROUND: The causes of oral clefts (cleft lip with or without cleft palate, CL/P, and cleft palate alone, CP) have not been established. However, maternal intrauterine hormone profiles have been suspected of being involved. There is now substantial evidence that maternal hormone concentrations around the time of conception partially control the sexes of offspring. It is possible that the hormone profiles that control sex of offspring share features of the profiles suspected of causing clefts. This can be tested by examining the sex ratios (proportions male) of the unaffected sibs of probands. If these sex ratios are skewed in the same direction as that of probands, that suggests, ex hypothesi, maternal hormonal involvement in the causation of clefts. METHODS: Accordingly, a search was made for data on the sex ratios of the unaffected sibs of probands with clefts. For reasons given in the text, this search was informal rather than based on electronic data retrieval systems. Nine papers were located giving sex ratios of sibs of probands with CL/P and CP. RESULTS: Published data suggest that the sibs of probands with CL/P have a significantly higher sex ratio than the sibs of probands with CP. Thus the sib sex ratios are skewed in the same direction as those of the probands themselves. In other words, parents (mothers) of CL/P patients apparently have a tendency to produce boys, and parents of CP patients to produce girls. CONCLUSION: Accordingly, it is suggested that maternal hormone profiles may partially explain the unusual sex ratios (of probands and their sibs), as well as the malformations.

Cleft Lip↗
PubMed2000

Why are boys more likely to be preterm than girls? Plus other related conundrums in human reproduction.

The present note offers two quite different points of interest. The first concerns the cause(s) of preterm labour. This is an important practical problem because of the associated morbidity and mortality. The second point of interest is theoretical. Some logically inter-related empirical propositions are formulated: none has been established but evidence for each is apparently evidence for all. However, as far as I know, there is no formal method of treating such material. It would be useful if methodologists would offer an opinion on whether the practical problem of the causes of preterm birth could be helpfully approached by the accumulation of data on the propositions outlined here. In my opinion, critics should not assess these propositions piecemeal, but should consider the whole edifice of propositions simultaneously. Obstetricians who confine their attention to the delivery of babies should extend it to the circumstances surrounding the conception of those babies. For there may lie the solution to the problem of why boys are more likely to be preterm than girls.

Animals↗
PubMed2000

Secular movements in sex ratios of adults and of births in populations during the past half-century.

There is some evidence for a small overall negative correlation across populations between sex ratio (proportion male) at birth and adult sex ratio. There seems to be no systematic correlation within populations across time of sex ratio at birth with adult sex ratio during the past 50 years. So even if adult sex ratios play some part in determining the overall level of the sex ratio at birth, they apparently have played little role in the recent widespread secular changes in sex ratio at birth. It is shown here that there is a strong cohort effect in adult sex ratios: if a woman is in a marriage squeeze (i.e. in a cohort with a relative abundance of women) at age 15 years, she will remain in such a squeeze for the rest of her reproductive life. In England and Wales, the maternal age-specific sex ratios at birth moved roughly in parallel across time during the years 1950-1995. This suggests that sex ratio at birth is not a cohort phenomenon (as it would be if it were affected by adult sex ratio) but is subject to some agents which change with time and affect women (parents) of all ages roughly equally.

Adolescent↗
PubMed2000

The variation of the probability of a son within and across couples.

It is suggested that there is a flaw in the currently accepted account of the variation of P, the probability of a boy, within and across couples. It was previously suggested that P has a mean (for Caucasian couples) of approximately 0.514 with an SD of approximately 0.05 across couples: and that the variation within couples is rather less. Grounds are offered here for suspecting that this formulation underestimates both SDs by a factor of as much as 4. It is suggested that in estimating these sources of variation, earlier workers did not consider the possibility that within-couple variation might be random and substantial. In view of the established epidemiology of human sex ratios, it now seems likely that such variation exists, and that there is a substantial measure of counterbalancing across-couple variation.

Female↗
PubMed2000

The influence of ethnic identity on drug use among ethnic minority adolescents.

Ethnic identity is a significant factor related to self-concept and psychological development and similar to other aspects of identity, is of particular importance during the adolescent years when there is increased vulnerability to drug involvement. However, much of the research relative to adolescent drug use has focused on the annual and current prevalence rates among particular ethnic groups with little attention to ethnic or group identity issues. However, it is important to study and compare ethnic and group identity and its correlates to drug use. This article presents face-to-face interview questionnaire measures of ethnic identity as measured by affirmation and belongingness, ethnic identity achievement, ethnic behavior, and other group orientation [1], and drug use as measured by misuse, abuse, and chemical dependency diagnoses [2]. The questionnaires were administered to 127 (60 Ethnic, 67 White) adolescents from ethnically diverse schools in a large urban school district in the Pacific Northwest. The relationship of ethnic identity to drug use was examined. This study indicates that the questionnaire measures can be used to examine similarities and differences in ethnic identity and drug use among adolescents from different ethnic groups. A key finding of this study was that white adolescents scored lower in ethnic identity than did members of the four ethnic minority groups and the mixed racial group. However, the most significant key finding was that in the ethnic minority sample high levels of cultural identity were associated with heavy drug use. The results of this study suggest that social influences may play a larger role in the development of heavy drug use irrespective of the nature and origins of these social influences.

Adolescent↗
PubMed2000

Youth dating violence.

Adolescents' responses to the Youth Dating Violence Survey have previously been documented by the Centers for Disease Control and Prevention (1996). The present study on dating violence examined the responses of thirty-seven adolescents enrolled in an alternative high school program. Many reported psychological victimization in a dating relationship: their partners did something to make them feel jealous, damaged their possessions, said things to hurt their feelings, insulted them in front of others, tried to control them, threatened them, blamed them for bad things the dating partners did, and brought up something from the past to hurt them. In terms of perpetrating psychological abuse in a dating relationship, over half of the adolescents reported that they hurt their dating partners' feelings, insulted them in front of others, did something just to make them jealous, tried to control them, and damaged their possessions. Many of the adolescents had also been victims of physical violence in their dating relationships; they reported being scratched, slapped, slammed or held against a wall, kicked, bitten, forced to have sex, choked, and pushed, grabbed, or shoved, as well as having their arms twisted and fingers bent. Some perpetrated physical violence in dating situations, such as scratching their dating partners, hitting them with a fist or something hard, throwing something that hit their dating partners, kicking them, slapping them, physically twisting their arms, slamming or holding them against a wall, bending their fingers, biting them, choking them, and pushing, grabbing, or shoving them. The findings confirm that dating violence among adolescents is a serious health problem that needs to be addressed.

Adolescent↗