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Biomedical subjects

E B Hook

Publications and source records attributed to E B Hook.

At least 181 records · Page 10Linked to original sources

Frequency of Down syndrome in livebirths by single-year maternal age interval: results of a Massachusetts study.

An analysis of rates of intra-state Down syndrome livebirths to Massachusetts residents by single-year maternal age interval in 1958-1965 inclusive was carried out. A gradual increase of rate of the Down syndrome occurred from age 20 to about age 31, and a steeper increase thereafter. Different regression equations were derived in the 20-31 and the 33-45 age group. The regression equations were ln y = 0.04515 x -1.45759 for those age 20-31 and ln y = 0.24302x-7.57870, for those age 33-45, where y = rate per 1,000 and x = maternal age. The regression-derived rates are slightly lower than those reported in similar analyses of data from Sweden and New York State, but they are not markedly discrepant.

Adolescent↗

The ratio of de novo unbalanced translocation to 47, trisomy 21 Down syndrome. A new method for human mutation surveillance and an apparent recent change in mutation rate resulting in human interchange trisomies in one jurisdiction.

The Down syndrome phenotype may be associated with, among other genotypes, an unbalanced Robertsonian translocation producing an "interchange trisomy" with 46 chromosomes, or 47, trisomy 21. Translocations, like specificlocus point mutations, result from a direct change in structural chromosome elements. In contrast 47, trisomy 21 results from meiotic non-disjunction. Mutation rates for interchange trisomies may be followed indirectly by determining the ratio of instances of Down syndrome associated with a new translocation mutation to those produced by 47, trisomy 21, which accounts for the bulk of the Down syndrome phenotype. This genotypic ratio can be analyzed in data from cytogenetic laboratories, clinics, and chromosome registries and does not depend upon intensive chromosome screening of newborn populations. A similar approach can be adopted to follow trends in Patau syndrome. The genotypic ratio, stratified by maternal age, may in addition, provide a sentinel index for changes in human specific-locus mutations and perhaps other adverse health consequences. Analysis of data from the New York State-North-eastern chromosome registry revealed a two- to three-fold increase in the genotypic ratio for both Down syndrome and Patau syndrome for individuals born in 1973, 1974 and 1975 compared to those born in earlier years.

Down Syndrome↗

Dietary cravings and aversions during pregnancy.

Interviews of 250 women concerning dietary changes during pregnancy were undertaken immediately after delivery. With regard to beverages, of women who regularly drank coffee or alcoholic items prior to conception, almost 30% reported a significant drop in ingestion during pregnancy. For coffee this change was attributed primarily to "endogenous" factors e.g., provocation of nausea or a loss of taste for the beverage. Concern regarding maternal or infant health was the most frequent reason for decrease in alcoholic beverages, although endogenous factors were also mentioned. Soda beverages were also ingested less frequently, predominantly because of dieting. The main increase was in milk consumption, primarily attributed to concern for the infant, but many mothers cited only a craving for the beverage. Other foods for which specific cravings were frequently cited were ice cream, sweets, and candy (particularly chocolate), fruits, and fish. Foods for which aversions outnumbered cravings were meats, poultry, and sauces flavored with oregano. Possible explanations for these changes associated with pregnancy are discussed.

Adolescent↗

Cardiovascular birth defects and antenatal exposure to female sex hormones.

In a cohort of 50,282 pregnancies 19 children with cardiovascular defects were born to 1042 women who received female hormones during early pregnancy (18.2 per 1000). Among 49,240 children not exposed in utero to these agents there were 385 with cardiovascular malformations (7.8 per 1000). Six children with cardiovascular defects were born to a sub-group of 278 women who used oral contraceptives during early pregnancy (21.5 per 1000). After the data were controlled for a wide variety of potentially confounding factors by multivariate methods, the association between in utero exposure to female hormones and cardiovascular birth defects was statistically significant.

Adult↗

Height and seriousness of crime in XYY men.

The case histories of XYY males in two security settings were ranked by degree of seriousness of crime. The correlations of these scores with height were either zero (for data of Daly with the history of the propositus excluded) or positive (for data of Jacobs et al., P less than 0.05). For both studies, the results were contrary to the expectation of negative correlation which would be found if, in accord with Hunter's suggestion, authorities were biased to place XYYs in security settings because of the more threatening appearance associated with larger stature.

Body Height↗

Exclusion of chromosomal mosaicism: tables of 90%, 95% and 99% confidence limits and comments on use.

Tables specifically tailored to the exclusion of cytogenetic mosaicism at three confidence levels are presented. The consequences of the assumption of independence in application of the binomial theorem to this question are discussed. The tables are most applicable to the number of cells evaluated from cultures in which all mitoses are arrested in the first in vitro division. For long-term cultures the tables are conservatively applicable to the number of separate colonies evaluated. If n cells have been evaluated from phytohemagglutinin stimulated peripheral blood after 72 hr in cultures, the tables are applicable to between n/2 and n cells.

Chromosomes↗

Consequences of a nationwide ban on spray adhesives alleged to be human teratogens and mutagens.

A report of an association of chromosome breakage and birth defects with spray adhesive exposure resulted in a ban on the sale of these products and nationwide publicity warning exposed women. Six months later the ban was removed; the association could not be confirmed. Replies to questionnaires sent to medical genetics centers throughout the United States revealed that more than 1100 inquiries had been received and more than 1200 working days were expended because of the issue. Eleven exposed women underwent diagnostic amniocentesis, and on elected to abort her fetus. Eight other women who were exposed also elected to do so, but without first undergoing diagnostic amniocentesis. The episode illustrates some of the unexpected and unnecessary consequenes that can arise from the false identification of an environmental agent as a mutagen or teratogen.

Drug and Narcotic Control↗

Some aspects of the epidemiology of human minor birth defects and morphological variants in a completely ascertained newborn population (Madison study).

In 4319 infants examined at birth who were without major birth defects those with a "remarkable" pregnancy outcome, i.e., low birth weight (less than 2500 g), long gestation (greater than or equal to 43 weeks), stillborn, or twin status, were more likely to have a minor birth defect than the remainder. With regard to the 2 most frequent defects, simian crease and folded helix, the increase in the former was of about the same order (1.6-2.1 -fold) in those with remarkable outcome of all types, but the increase in the latter was particularly great in twins (approximately 3.1-fold) compared with the other remarkable outcomes (approximately 1.3-fold). With regard to variants, which were defined as those features scored that occurred in 4% or more of the newborn population, some (flat and small hemangioma on face and scalp, Brushfield spots, flat nasal bridge, hyperflexed thumbs, hydrocele, and mild calcaneovalgus) exhibited a trend towards negative association with low birth weight and a trend to positive association (with exception of hemangioma and calcaneovalgus) with long gestation, suggesting they may simply be indirect markers of gestational age. There was a trend to a slight decrease in the frequency of minor defects with increasing maternal age, similar to the trend for major defects.

Adolescent↗

Chromosome breakage in low birth weight newborns.

The frequency of chromosome aberrations in cells cultured from umbilical cord blood was determined for 50 low birth weight (LBW) and 50 normal birth weight (NBW) euploid newborns matched for sex, race, and maternal age. The metaphase spreads had been prepared in the course of an earlier study of frequency of aneuploidy and results are from 72-h cultures, i.e., presumably, at the second division in vitro. There were no significant differences between the two groups in the frequency of cells with chromosome breakage, chromosome gaps, or hyperdiploid cells. There was, however, a significantly higher frequency of hypodiploid cells in the LBW group. The present findings differ from those of others who have reported an increase in chromosome breakage in premature newborns.

Body Weight↗