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N M Blake

Publications and source records attributed to N M Blake.

At least 37 records · Page 2Linked to original sources

Genetic studies on the Chenchu Tribe of Andhra Pradesh, India.

A total of almost 200 members of a tribal group, the Chenchu from the Mahabubnagar and Kurnool districts of Andhra Pradesh, have been tested for electrophoretic variation in a number of red cell enzyme systems. The former population has also been tested for ABO, MN and Rh blood group systems and for the serum proteins Hp, Tf and albumin. The most significant findings were the presence of the gene ry, and the occurrence of a polymorphism in PHI with the variant gene PHI5 having a gene frequency of 4%.

Blood Group Antigens↗

Genetic studies on the Kolams of Andhra Pradesh, India.

A total of 220 persons belonging to the Kolam tribe in the Adilabad District of northwest Andhra Pradesh have been tested for 18 red cell eyzyme systems and for haemoglobin. Generally, the gene frequencies for the systems which showed electrophoretic variation were within the range for Indian populations; the gene frequency for AK1 is high by Indian standards and Hb AS is present. LDH Calcutta 1 was not detected in this population and a single example of PHI 2-1 was observed.

Acid Phosphatase↗

The frequency of private electrophoretic variants in Australian aborigines and indirect estimates of mutation rate.

The number of "private" electrophoretic variants of enzymes controlled by 25 loci has been used to obtain estimates of mutation rate in Australian Aborigines. Three different methods yield values of 6.11 X 10(-6), 2.78 X 10(-6), and 12.86 X 10(-6)/locus per generation for the total sample of Aborigines. One tribal population of Waljbiri in central Australia gives values of 2.99 X 10(-6) and 2.04 X 10(-6) for two of the methods, the third being unapplicable. The mean mutation rate for the total Aboriginal sample of 7.25 X 10(-6) is very similar to the value obtained by Neel and his colleagues for Amerindians in South America.

Australia↗

Malate dehydrogenase types in the Asian-Pacific area, and a description of new phenotypes.

A survey of more than 21 000 haemolysates from blood samples collected in various parts of south and southeast Asia, Australasia and the Western Pacific and examined in this laboratory has revealed several new alleles controlling variants of sMDH; in addition, further information has been provided on the distribution of sMDH3 in New Guinea. Two of the variant alleles, sMDH3 and sMDH6, achieve polymorphic frequency in various populations. sMDH3 is widely distributed in New Guinea, with highest frequencies in the Eastern Highlands. The pattern of its distribution suggests the mutant arose originally in a Papuan-speaking population. So far, sMDH6 has been detected only in Micronesians from a number of islands in the Carolines. A single example of another new variant, sMDH 5-1, and two examples of a slow variant, sMDH 7-1, were detected in samples from Iran and Singapore, respectively. No examples of mMDH variants were found in a total of 652 placental extracts from Papua New Guinea and Australia.

Australia↗

Widespread distribution of variant forms of carbonic anhydrase in Australian aboriginals.

Three distinctive genes which control variants of carbonic anhydrase (CA) have been detected in tests on nearly 3000 Aboriginals from various parts of Australia. Two of these genes affect the products of the CA1 locus, the other affects the products of the CA2 locus. In some populations of Aboriginals, more than 10% of persons have a variant carbonic anhydrase. It is suggested that such an unusual frequency of CA variants may be an evolutionary response to metabolic stress connected either with low zinc concentrations in the diet or with the altered needs of ion regulation in an arid environment.

Alleles↗

Genetic variants of carbonic anhydrase in the Asian-Pacific area.

The results of extensive surveys of red cell carbonic anhydrase phenotypes in the Asian-Pacific region are presented together with data on the occurrence of three new polymorphisms present only in Australian Aboriginals. Two of these systems are widespread right across the Australian continent, while the remaining one is restricted to members of a single linguistic group in Arnhem Land. Further examples of CA1 3-1 Guam are reported, and also CA1 3-1 Singapore which has an electrophoretic mobility indistinguishable from that of CA1 3-1 Guam. Included in the tabulations are data on other populations outside the Asian-Pacific area and, for completeness, information already published on variants of both CA1 and CA2. In an effort to simplify the nomenclature of carbonic anhydrase variants, a new system is suggested, using numerals rather than letters to distinguish the variant isozymes. Modifications of the electrophoresis buffer system which enhances the very small mobility differences existing between several of the products of the CA1 alleles are also described.

Asia↗

A population genetic study of the Vania Soni in Western India.

A total of 267 blood samples from persons belonging to the Shrimali Vania Soni caste group in Gujarat State, Western India have been analyzed for 6 blood group, 4 serum protein and 19 red cell enzyme systems, for haemoglobin and beta-thalassaemia and for red-green colour blindness. A number of rare genetic variants were detected, including a unique electrophoretically fast variant of superoxide dismutase. Genetic distance comparisons with other caste groups in Gujarat State show that Vania Soni from Surat are a distinctive group clustering with another subdivision of the Vania. The remaining Vania Soni cluster together and are distinct from the other caste groups examined in Gujarat. However, on the basis of individual genetic markers the Vania Soni appear not to be genetically differentiated in any remarkable way from other Hindu populations in western and northern India.

Blood Group Antigens↗

Genetic studies on the Savara and Jatapu Tribes of Andhra Pradesh, India.

A total of nearly 300 persons belonging to the Savara and Jatapu tribes in the Srikakulum District of northern Andhra Pradesh have been tested for electrophoretic variation in 13 red cell enzyme systems, and also haemoglobin. The gene frequencies for the systems showing variation are within the range for other South Indian populations, and there are no significant differences between the two tribal groups investigated in this report except in the case of adenylate kinase. The Jatapu (along with the Kadar of Kerala) have the highest frequency of AK1 so far reported in India. Both the Savara and Jatapu showed a low frequency for Hb AS, and LDH-Calcutta 1 was not detected in either population.

Acid Phosphatase↗

Genetic components in susceptibility to nasopharyngeal carcinoma.

A series of blood samples from more than 200 histologically confirmed Chinese patients with NPC in Singapore were typed for 25 genetically controlled red-cell enzyme and five serum protein systems. A comparable number of patients suspected of having NPC but histologically negative and a series of healthy unrelated Chinese were typed for the same systems. The gene frequencies of NPC patients and controls differed by 4% or more in four of the 11 systems that showed variation; a further system, G6PD deficiency, also showed a significant difference between the two series but was excluded because of possible unreliability of the results from patients. Smaller differences existed in several other systems, including chromosome 6 markers closely linked to HLA. An analysis of differences within dialect groups showed a consistent effect for PGD, but for red-cell acid phosphatase there was a reversal of the difference between patients and controls among the Cantonese. These results need a larger series to confirm their validity. A breakdown of patients into those 30 years of age or older and those under 30 slightly enhanced the differences in gene frequencies. A multivariate analysis, using genetic distance statistics, showed a significant difference between NPC patients and controls, which is evident also when they are compared in the separate dialect groups. The histologically negative patients occupied an intermediate position. The study indicates that etiological factors resulting in clinically and histologically confirmed NPC operate on a genetically distinct subpopulation of Chinese in Singapore.

Acid Phosphatase↗

Genes and people in the Caspian Littoral: a population genetic study in Northern Iran.

Data for the distribution of alleles controlling two blood group systems and secretor status, for hemoglobin types, five serum protein groups and 15 red cell enzyme systems has been obtained. Eleven of the systems showed polymorphic variation and these systems have been used to calculate genetic distances using Morton's Kinship measure. No systematic relationship between genetic distance and geographic location of linguistic affiliation is apparent. There is, however, an apparent cline of decreasing frequency of PGDc from east to west and also significant differences in the frequency of G6PD deficiency corresponding to variation in the ecology of the region. Genetic distance comparisons with other selected populations reveal that the Turkic and Turkoman speaking peoples in the Caspian area cluster with the Kurds, Greeks and Iranis. The Persian speakers are genetically remote from these populations; they are, however, close to the Parsis who migrated from Iran to India at the end of the Seventh Century A.D. Several unusual genetic variants were detected, including a novel MDH phenotype, a superoxide dismutase phenotype identical with the Scandinavian type, and rare forms of LDH, PGM locus 2, ceruloplasmin, diaphorase, peptidases and PHI.

Acid Phosphatase↗

HLA types, blood groups, serum protein and red cell enzyme types among Samoans in New Zealand.

101 Samoans living in New Zealand, of whom 77 had no known non-Samoan ancestry, have been typed for nine blood group systems, four serum protein and 23 red cell enzyme systems, for haemoglobin variants and antigens at the HLA A nad B loci. The frequencies of genes in these various systems suggest that Samoans fall partly into an island Melanesian-Micronesian pattern, and partly are unique. Their uniqueness is most distinctive for the HLA system.

Acid Phosphatase↗

Glutamic pyruvic transaminase and esterase D types in the Asian-Pacific area.

More than 11000 blood samples have been examined for glutamicpyruvic transaminase (GPT) and almost 9000 for Esterase D(EsD) in the Asian-Pacific area; GPT3 and GPT6 were detected in several population groups in New Guinea, Singapore and some Pacific islands. No previously undescribed alleles were found in either system.

Alanine Transaminase↗

Phosphoglucomutase types in the Asian-Pacific area: a critical reveiw including new phenotypes.

The distribution of genetic variants at the PGM1 and PGM2 loci in South and East Asia, the Western Pacific and Australasia has been surveyed on the basis of published and unpublished material comprising samples from some 33,000 persons. A critical comparsion of previously described and of new rare alleles at both loci has been undertaken. The present number for PGM1 is 14 and for PGM2 is 12. Many of these have restricted geographic or ethnic distribution.

Alleles↗