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Biomedical subjects

T Jenkins

Publications and source records attributed to T Jenkins.

At least 253 records · Page 14Linked to original sources
PubMed1976

Prenatal diagnosis and selective abortion.

The Abortion and Sterilisation Act, 1975, has been in force for 1 year. Experience gained in the Johannesburg area in the operation of the Act with respect to termination of pregnancies for abnormalities of the unborn child, is outlined. Relatively few abortions have, in fact, been carried out for this reason, but the number is likely to increase. Prenatal diagnosis of disease in the fetus, although not possible in all cases, has greatly facilitated the management of families in which a child with a heritable disorder may be born.

Abortion, Therapeutic↗
PubMed1976

The prenatal diagnosis of Tay-Sachs disease.

Tay-Sachs disease was diagnosed prenatally on the basis of enzyme assays and the electrophoretic pattern of extracts made from cultured amniotic fluid cells. Electrophoresis revealed the presence of hexosaminidase B but no hexosaminidase A, the iso-enzyme which is deficient in Tay-Sachs disease. Estimations of the percentage of hexosaminidase A present in cultured amniotic cell extracts by means of thermal fractionation revealed the presence of only small amounts of this isozyme. Results obtained on amniotic fluid alone were found to be unreliable and were disregarded when making the diagnosis. Following termination of the pregnancy, the diagnosis was confirmed by electrophoresis and the thermal inactivation method as well as by electron microscopy. A slight lower temperature for the thermal inactivation has been found to give better discrimination than the temperature used in previously described techniques.

Amniotic Fluid↗
PubMed1976

Deficiency of adenosine deaminase not associated with severe combined immunodeficiency.

The 12-year-old Kung (""Bushman'') boy from South West Africa who has marked deficiency of red cell adenosine deaminase has been found to have 2 to 3% of enzyme activity in red blood cells, 10 to 12% in leukocytes, and 10 to 30% in cultured fibroblasts. The enzyme has ADA 1 electrophoretic mobility: SV40 transformation of cultured fibroblasts caused a decrease of ""tissue ADA'' and an increase in ""red cell ADA'' isozymes. A battery of investigations revealed that the child has normal humoral and cellular immunity. A family study showed that a sibling had the same level of red cell ADA and the parents had intermediate levels. Studies of the Kung population from which the child comes have shown that the allele responsible for the condition, and which we designate ADA8, is polymorphic.

Adenosine Deaminase↗
PubMed1976

Sero-genetic studies on the Dama of South West Africa.

The Dama of South West Africa are a Negroid people living as a reproductive isolate in the desert and semi-desert areas of the north-west of the country. Until recent times a large proportion of them were held in bondage by the Khoikhoi (Hottentot) Nama, while the rest lived as hunter-gatherers in the mountains. This study and the work of Knussmann and Knussmann indicate that they are a Negro people, which probably has been cut off over a period from contact with other Negroes. They have received very little genetic contribution from the Khoikhoi or the San (Bushmen). The results of this investigation of 24 blood genetic marker systems in a carefully selected random sample of Dama support these conclusions.

ABO Blood-Group System↗
PubMed1975

The Griqua of Campbell, Cape Provice, South Africa.

The Griqua of Campbell in the Cape Province of South Africa are reputed to be descended from an amalgam of Khoi ("Hottentots") with various Caucasoid, Negroid and East Asian elements at the Cape of Good Hope. A stormy history of migration and deprivation has left this small residuum on the edge of the Kalahari Desert. It was hoped that a sero-genetic study of these people, who proudly preserve their identity, might provide further insights into the genetic consitution of their Khoi forebears. Despite the retention of the language of their own, an social mores distinct from of other Mixed populations, they have been shown, however, to have received an appreciable inflow of non-Khoisan genes. This has probably resulted from social factors such as the prestige attaching to Griqua membership and the willingness of the Griqua to assimilate outsiders, combined with the tendency of Campbell Griqua to migrate elsewhere. There are no significant differences between "Griqua" members of the population and those who are not recognized as "Griqua."

Black People↗
PubMed1975

Sero-genetic studies on the G/wi and G//ana San of Botswana.

The G/wi and G//ana San ('Bushmen') of the Central Kalahari Reserve, Botswana, live as cyclically migrant hunter-gatherer bands. They have some contact with one another, with the Negro Kgalagadi, and with White farmers near Ghanzi. Studies carried out on samples of these peoples from the Okwa Valley reveal a sero-genetic profile characteristic of the San in general, deviant from that of the Khoi ('Hottentots') and quite different from that of the Negroes. These findings help to substantiate the claim that the Khoisan peoples should be regarded as one of the major divisions of mankind and not simply as having comparatively recently evolved from a common stock with the Negroes.

ABO Blood-Group System↗
PubMed1975

Gammaglobulin groups of the Khoisan peoples of Southern Africa: evidence for polymorphism for a Gm1,5,13,14,21 haplotype among the San.

The Gm and Inv types were determined for eight San (Bushman) populations, two Khoikhoi (Hottentot) populations, one Coloured population, 112 San families in which the genotypes of the parents could be unambiguously determined, and for 65 San families in which the genotype of one or both parents could not be determined with certainty. The population and family data establish that the haplotype array of the San is composed of Gm1,21, Gm1,13, Gm1,5,13,14, and Gm1,5,13,14,21; Gm1,5,6 and Gm1,5,6,14 are also present but may have been acquired through admixture with Negroes. The Gm1,5,13,14,21 haplotype has not been found to be polymorphic in any other population. The haplotype array of the Khoikhoi is composed of Gm1,2,21, Gm1,13, and Gm1,5,13,14; Gm1,5,6 and Gm1,5,6,14 are also present but, as in the case of the San, may be due to admixture. The San and Khoikhoi differ from each other in that the former have the Gm1,21 and Gm1,5,13,14,21 haplotypes not present in the latter, and the Khoikhoi have the Gm1,2,21 haplotype not present in the San. These three haplotypes and Gm1,13 serve to distinguish the Khoisan people from other African peoples.

Africa, Southern↗
PubMed1974

Public health and genetic constitution of the San ("Bushmen"): carbohydrate metabolism and acetylator status of the Kung of Tsumkwe in the North-western Kalahari.

Intolerance to lactose owing to deficiency of lactase is particularly prevalent among non-Caucasian peoples. Special caution is therefore needed in offering them milk supplements. Lactose tolerance has been investigated among the!Kung in the north-western Kalahari. The opportunity was taken also to examine their acetylator status, as this affects their ability to detoxicate drugs given for the treatment of tuberculosis and other diseases.The preliminary studies reported here suggest that not more than 10% of the!Kung are tolerant to lactose, but only one person out of 30 was a slow acetylator.

Acetylation↗