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Biomedical subjects

W H James

Publications and source records attributed to W H James.

At least 19 recordsLinked to original sources
PubMed1995

Fraud and hoaxes in science.

The recent spate of moral condemnation of fraud in science reflects the conservative nature of scientists; fraud, like error, is a normal part of science and cannot be legislated away.

Humans↗
PubMed1995

Sex ratios of offspring and the causes of placental pathology.

The sex ratios of offspring associated with various types of placental pathology were studied in order to investigate whether this may throw light on the causes of the pathology. The literature was searched for data on the sex ratios of offspring associated with: abruptio placenta, placenta praevia, placenta accreta, extrauterine pregnancy, acute fatty liver of pregnancy or toxaemia of pregnancy. Highly significant male excesses associated with abruption placenta, placenta praevia, fatty liver of pregnancy and toxaemia were noted. Highly significant female excesses were found to be associated with placenta accreta and extrauterine pregnancy. Each type of pathology is associated with a typically biased offspring sex ratio. No explanation of this has ever been offered, so it seems worth postulating that the abnormal sex ratios are caused by abnormal hormone concentrations at conception, and that these are associated with abnormal hormone concentrations later on which are partially responsible for the pathology. The point could be tested by examining the extent to which hormone concentrations control first, Fallopian tube motility, and second, infiltration by extravillous trophoblasts into the placental bed.

Fatty Liver↗
PubMed1995

What stabilizes the sex ratio?

It is suggested that the human sex ratio at birth is stabilized only to a minor extent by the direct processes of natural selection. Instead the major factors stabilizing sex ratio seem to be behavioural (coital rates) and psychological (parental perceptions of adult sex ratios). It is suggested that parental hormone levels are (a) a consequence of perceived adult sex ratios, and (b) a cause of sex ratio in the next generation, thus providing the basis for a negative feedback process stabilizing the sex ratio.

Female↗
PubMed1992

The hypothesized hormonal control of mammalian sex ratio at birth--a second update.

Further evidence is adduced to support the hypothesis that the sexes of mammalian (including human) offspring are partially controlled by parental hormone levels at the time of conception. The evidence relates to variation of sex ratios at birth with (1) time of insemination within the cycle of several species, (2) excision of accessory sex glands in rodents, (3) occupation of parents, (4) dominance rating of human mothers and (5) the ordinal rank of wives in polygynous marriages. Much medical research will stem from the hypothesis if it proves to be true. (a) If it were, there would be implications for the testing of causes of many diseases: and it is noted here that the sex ratios of offspring of victims of two types of cancer (prostatic cancer and non-Hodgkin's lymphoma) are consistent with the suspected causes of these diseases. (b) There are a large number of rheumatic diseases associated with the HLA markers B 27 and B 8. These markers are apparently associated respectively with high testosterone levels in men and low testosterone levels in women. If these finding should be confirmed, a causal role for this hormone seems likely in some of these diseases. It will be interesting to examine sex ratios of relatives of probands with these diseases.

Animals↗
PubMed1992

The current status of Weinberg's differential rule.

A reanalysis of the data presented in a recent large twin study suggests that opposite-sexed (OS) pairs may be not as exhaustively tested as same-sexed (SS) pairs on genetic markers. This is contrary to an assumption I made in estimating that there are about 8 SS dizygotic pairs to every 7 OS pairs (thus impugning Weinberg's differential rule). If this assumption is false also in regard to the samples I discussed, then that estimate is unsound and Weinberg's rule is unscathed by empirical data. However, regardless of such considerations, there are strong theoretical reasons for questioning the status of Weinberg's rule. It is based on two assumptions, namely that p (the probability that a dizygotic twin zygote is male) is equal and independent for all dizygotic twin zygotes. Data are adduced here to suggest that both assumptions are false. The upshot is that, at present, without testing, we cannot know, of any given population, whether the rule holds or not. Otherwise, though Weinberg's rule may be useful (like Hellin's law) as a rule-of-thumb, it cannot be assumed as a basis for serious scientific argument.

Animals↗