Biomedical subjects
W H James
Publications and source records attributed to W H James.
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.
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.
Coital frequency and twinning. A comment.
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The sex ratios of dyslexic children and their sibs.
There is a male excess in many samples of patients with dyslexia and related conditions. Various suggestions have been made to account for this, including: (1) ascertainment bias, in that boys are more likely to be referred than girls; (2) a biological propensity of parents of dyslexic children to produce a high proportion of boys (compared with parents of controls); and (3) greater susceptibility among boys than girls to these conditions. These explanations are not mutually exclusive, and the first undoubtedly applies to some clinic samples. This paper offers equivocal evidence for the second explanation, and introduces new evidence for the third.
Sex ratio, testosterone and postpartum thyroid dysfunction.
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Maternal personality and sex of infant: a comment on Grant.
Grant (1990) reported significantly higher dominance scores during pregnancy of mothers who later bore sons than mothers who later bore daughters. Such findings have been reported in other species, and evidence is adduced here to suggest that this difference is not wholly a temporary effect of the pregnancy but probably pre- and post-dates the pregnancy.
Handedness, accidents, and mental state.
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Sex ratios, HLA markers, and rheumatic diseases.
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Age at presentation with ankylosing spondylitis.
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The combinations of the sexes of mammalian sibs and littermates: and the possibility of adaptive control.
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Further evidence that pesticides or herbicides cause non-Hodgkin's lymphoma.
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Sex ratios as markers for hormone levels in cancer.
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Birth order in multiple sclerosis.
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Sex ratios and hormones in HLA related rheumatic diseases.
The major diseases associated with HLA-B27 (Reiter's disease, ankylosing spondylitis, acute anterior uveitis, and psoriatic arthritis) all occur much more commonly in men. Published evidence indicates that the antigen HLA-B27 is associated with high testosterone concentrations in men. Moreover, the antigen HLA-B44 exerts a protective effect on one of these diseases (psoriatic arthritis), and there are external grounds for supposing that HLA-B44 indexes an antiandrogenic process. These data are interpreted as support for the hypothesis (first adumbrated nearly 20 years ago) that HLA antigens index unusual hormone concentrations, which in turn are causally related to the diseases. An examination of published reports suggests that sibs of probands with ankylosing spondylitis (and perhaps Reiter's disease) contain an excess of men, and that sibs of probands with rheumatoid arthritis contain an excess of women. These data lend further support to the hypothesis.
The sex ratios of probands and of secondary cases in conditions of multifactorial inheritance where liability varies with sex.
Some pathological conditions affect one sex more often than the other. A curious feature of some of these conditions (dyslexia, congenital dislocation of the hip, pyloric stenosis, otosclerosis, lupus erythematosus, ankylosing spondylitis) is that the sex ratio (proportion of males) of randomly ascertained probands is more extreme than that of their affected relatives. In all these conditions, multifactorial inheritance has been suspected. A simple model is offered here of multifactorial inheritance with liability varying by sex. Under the model, such a disparity between sex ratios would be expected.
HLA markers, hormones, and disease.
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Modelling sub-binomial variation in the frequency of sex combinations in litters of pigs.
In some samples of pig litters, the number of males per litter exhibits significant sub-binomial dispersion: there are fewer unisexual and more "sex-balanced" litters than expected under a binomial model. It is argued here that the explanation is that the sex of zygotes may be subject to hormonal control with the consequence that, within a litter, the zygotes do not all have the same probability of being male. This variation in probability is approximated by a quadratic function of the time during oestrus that a zygote is formed so as to parallel the variation in maternal hormone levels. Other explanations are examined briefly, but each seems to have serious weaknesses.