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Biomedical subjects

R W Smithells

Publications and source records attributed to R W Smithells.

At least 73 records · Page 4Linked to original sources

The challenges of teratology.

Teratology has its origins in the descriptive anatomy of malformed humans. Although the term now has much wider connotations, the first challenge of teratology is to recognise its purpose as a science related to a human problem. The wider connotations inevitably mean the involvement of increasing numbers of disciplines, each with its own language and limitations, but each with a unique contribution to make. The second challenge of teratology is therefore to establish and expand communications between these disciplines. The third challenge is teratogenesis, which requires a rather more profound consideration of the nature of causation than a simple cause-and-effect relationship. At the same time as looking back from consequences to causes, we must look forward from the causes to alternative consequences. The affinity of teratogenesis, carcinogenesis, and mutagenesis constitutes the fourth challenge. The fifth challenge brings us back to humans, and lies in the relationships between scientists working within the field of teratology, and industry, the law, the media, and the public at large.

Abnormalities, Drug-Induced↗

Teratogenicity testing in humans: a method demonstrating safety of bendectin.

We investigated the incidence of birth defects in the offspring of women who took Bendectin during pregnancy. Copies of all prescriptions issued for Bendectin in two Cities, Leeds and Liverpool, over periods of 12 and 14 months, respectively, were scanned and a record initiated for each patient. Birth notifications were later searched for matching with indexed patients. Births were traced for 2,298 patients and the incidence of major defects compared with those in the relevant populations. We found no evidence to suggest that Bendectin is teratogenic in humans.

Abnormalities, Drug-Induced↗

Leucocyte ascorbic acid and pregnancy.

1. Leucocyte ascorbic acid concentrations have been measured in 1147 females during early pregnancy and in smaller numbers of women before conception, throughout pregnancy and at 6 months post partum. 2. The leucocyte concentration in the 1st trimester was found to be affected by season, social class and smoking. Selecting individuals by extremes of social class, season and smoking produced two small populations with almost separate ascorbic acid distributions and mean concentrations of 21.7 and 45.1 microgram/10(8) leucocytes. 3. Early pregnancy had little effect on leucocyte ascorbic acid concentrations but values decreased in the second trimester. However, this was associated with a leucocytosis so that the total leucocyte ascorbic acid content of blood was unchanged. 4. Low ascorbic acid concentrations during the 1st trimester were not associated with subsequent spontaneous abortions, still-births or neonatal deaths, but there was an increased frequency of low values in women who gave birth to infants smaller than 3250 g. 5. The adequacy of ascorbic acid reserves in early pregnancy is discussed.

Adult↗

Maternal nutrition in early pregnancy.

1. Mean daily nutrient intakes of 195 women in the first trimester of pregnancy were assessed by weighed dietary records. 2. In comparsion with recommended intakes for non-pregnant women aged 18-55 years (Department of Health and Social Security, 1969), more than two-thirds of the subjects were having insufficient energy, iron and cholecalciferol. Unsatisfactory intakes of other nutrients were not uncommon. In relation to recommended intakes for the second trimester (Department of Health and Social Security, 1969), all mothers were having insufficient cholecalciferol and more than 80% of mothers had unsatisfactory intakes of energy and Fe. 3. Intakes appreciably lower than those recommended were associated with the following factors: social classes III, IV and V; maternal age under 20 years; smoking ten or more cigarettes daily; vomiting on more than 3 d/week.

Adult↗

Poliomyelitis-like illness after acute asthma.

Two children had pain in one arm, followed by weakness and wasting, after an acute exacerbation of bronchial asthma. Similar cases in which a poliomyelitis-like illness was associated with acute asthma have been reported, but the relationship between the two remains conjectural.

Arm↗

Parity of women contracting rubella in pregnancy. Implications with respect to rubella vaccination.

Data from the National Congenital Rubella Surveillance Programme showed that 44% of children with congenital rubella reported to the programme were born to primiparae. This high proportion is thought to be due to the fact that there was a two-fold increase in the rate of abortion for rubella in pregnancy for women with two or more children. This higher incidence of congenital rubella in firstborns emphasises the need for rubella vaccination prior to a woman's first pregnancy.

Abortion, Therapeutic↗