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Biomedical subjects

D S Dunn

Publications and source records attributed to D S Dunn.

26 records · Page 2Linked to original sources

Transition from a hunter-gatherer to a settled lifestyle in the !Kung San: effect on iron, folate, and vitamin B12 nutrition.

In 1969 a group of hunter-gatherer San were studied (Am J Clin Nutr 1971;24:229-42). Their state of hematological nutrition was excellent with a negligible incidence of iron, folate, or vitamin B12 deficiency. A genetically and linguistically similar San community who have been settled for the past 15 yr were the subjects of the present study. Anemia, due in the main to iron and/or folate deficiency, has become more common. Alcoholism has become rife in both sexes and all age groups. Our findings show that a settled lifestyle has resulted in a significant deterioration in the San's hematological nutrition.

Adolescent↗

Phophoglucomutase first locus polymorphism as revealed by isoelectric focusing in Southern Africa.

Eleven Southern African populations (representing European, Asian and Negroid populations) have been typed for the first locus phosphoglucomutase (PGM1) using isoelectric focusing (pH range 5.0-8.0) in acrylamide gels. The gene frequencies of the four common alleles at this locus in these populations were compared to those found previously in European and Negroid populations. Marked differences in gene frequencies were observed: Negroes have a lower PGM1(2-) compared with Caucasoids due to a lower PGM1(2-) frequency, Indians a relatively high PGM1(2) due to a higher frequency of the PGM1(2+) allele. The Afrikaans and Ashkenazim do not differ appreciably from their European counterparts. The appearances of the rarer PGM1(6) and PGM1(7) alleles on isoelectric focusing are described and some kinetic properties examined. The PGM2(2-1), or 'Atkinson' phenotype, can also be detected with this technique.

Africa, Southern↗

Retrograde ejaculation and pregnancy. A case report.

A patient with retrograde ejaculation following a transurethral resection of the prostate was able to father a child using spermatozoa recovered from the bladder. The method of recovery of these spermatozoa is described.

Ejaculation↗

Serogenetic studies on the Daga of the interior of the mainland of Milne Bay Province, Papua New Guinea.

The Daga people of Milne Bay, the easternmost Province of Papua New Guinea, occupy an upland area but do extend to the coast. Linguistically they are Papuan and, unlike their Austronesian-speaking neighbours, they appear originally to have been an exclusively inland people. They have been in contact with missionaries and miners since the turn of the century, and genetic evidence of Caucasoid gene flow may be present in the finding of several lactose absorbers (reported elsewhere). They are the first non-Australian population in whom the second carbonic locus allele CA4II has been detected, which may indicate either recent gene flow from Australian aborigine or lend additional support to the suggestion that there was Australian contact with Papua before the coming of the Europeans. For the rest, their gene-marker profile is fairly typical of a non-highland population of New Guinea, though the low frequency of hereditary ovalocytosis tends to confirm their inland origins.

Alleles↗

Serogenetic and haematological studies on the Kgalagadi of Botswana.

A sample of Kgalagadi, Negro speakers of a Sotho/Tswana Bantu language, inhabitants of Botswana, have been investigated for variation in 27 gene-marker systems and for haematological status and the presence of intestinal parasites. They have been found to show indications of genetic affinity both to the other Sotho/Tswana and to the Mbanderu divisions of the Herero, a Bantu-speaking Negro people of Namibia. The latter affinity appears the closer. Although the historical connection between the peoples seems unlikely on cultural and oral-historical grounds, it is not impossible, given the shallow depth of the oral history of the Herero and the consequent doubts about the antiquity of their present cultural system. Nothing in the genetic profile of the Kgalagadi contradicts the claim that they represent a very early, and perhaps the first, wave of Negro immigration into southern Africa. They have been investigated for intestinal parasites and haematological status as well. They appear to be haematologically healthy, and to possess only the narrow range of parasites previously found in the Kalahari Desert, apart from one subject in whom Hymenolepis nana (Dwarf tapeworm) was found.

Adolescent↗

Study of 30 DNA markers in three southern African populations.

Thirty anonymous DNA markers were investigated in Southern African Caucasoid, Negroid and San populations. Sixteen of these are new markers that were developed in our laboratory; the remainder are closely linked to the cystic fibrosis locus on chromosome 7. Average heterozygosity in the Caucasoid and Negroid populations was calculated at the loci identified by each of the anonymous probes, using two approaches, and was found to be .0020 and .0030 for the Caucasoid population and .0023 and .0025 for the Negroid population. Variation between populations (measured by FST) and between markers was calculated from allele frequency data gathered for all markers in the three populations. Significant differences in allele frequency between the populations were observed for the cystic fibrosis markers MET D, MET H and 7C22, with little or no variation observed in the Negroid and San populations. Mean heterozygosity (D) was found to be considerably lower in San (.250) than in Caucasoid (.373) and Negroid populations (.0320) and possible explanations for this are provided. The smallest genetic distance (60 x 10(-3)) was found between the Negroid and San populations, and the greatest distance between the Caucasoid and San populations (167 x 10(-3)).

Africa, Southern↗

HLA-A, B and C polymorphisms in three major populations living in South Africa.

The HLA class I antigen gene and haplotype frequencies of three major population groups living in the Transvaal province of South Africa were determined. The HLA-A, B and C antigens were tested in 877 South African Negroids, 381 Coloured and 771 Caucasoids. Differences in gene and haplotype frequencies between the various populations were observed. HLA-A11 appears with a low frequency in the Negroids (gf = 0.004) and the Caucasoids revealed an absence of HLA-Bw70. The frequencies of the HLA antigens in the Coloured population were generally intermediate between those of the other two groups. The most frequent haplotypes were A3, B7; A30, B8 and A2, B58 in the Caucasoids, Negroids and Coloured respectively. Genetic distance analysis reveals that Negroids and Caucasoids are distinct groups and the Coloured occupy an intermediate position.

Black People↗