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Biomedical subjects

K Omoto

Publications and source records attributed to K Omoto.

At least 109 records · Page 6Linked to original sources
PubMed1981

The HLA antigens of two Negrito populations in the Philippines.

HLA antigens were determined for the A, B and C loci among 86 Aetas of west-central Luzon and 87 Mamanwas of north-eastern Mindanao, Philippines. The overall antigenic profiles of these two groups were essentially similar to those of other Asian-Pacific populations with some peculiarities in common with Papua New Guineans. However, the results of heterogeneity tests and the comparison of statistically significant phenotypic associations showed a highly significant difference between the Aeta and the Mamanwa groups. It was postulated that the two "Negrito" groups represent different migrations to the Philippines.

Black People↗
PubMed1981

Population genetic studies of the Philippine Negritos. III. Identification of the carbonic anhydrase-1 variant with CA1 Guam.

Investigation of blood samples from 277 Mamanwas of northeastern Mindanao, Philippines, confirmed the concentration of the variant carbonic anhydrase-1 (CA1 3N) in this group. The frequency for the variant allele was estimated at .217 +/- .017. It occurs also in the Manobos, the Mongoloid indigenous inhabitants of the same district, although the frequency is low (.019 +/- .008). Survey of samples from other Philippine populations, including the Aeta and the Ifugao of Luzon, failed to find variants. This findings suggests different origins of the Aeta and the Mamanwa, although both are usually referred to as Negritos. The Ca1 3N protein was purified by affinity chromatography using azosulfonamide and rechromatography on a DEAE-Sephadex column. The tryptic peptide pattern of CA1 3N was similar to that of CA1 Guam already reported. Furthermore, amino acid analyses of the tryptic peptides indicated that CA1 3N is characterized by the substitution 253 Gly leads to Arg, confirming the identity of this variant with CA1 Guam. The widespread occurrence of CA1 3 variants in the Western Pacific suggests that this variant was once common in an aboriginal population of this region, from which it was scattered by gene flow.

Black People↗
PubMed1980

Genetic variants of red cell enzymes as potential anthropological markers in the Western Pacific.

During the population genetic surveys of the aboriginal Negrito groups of the Philippines, "rare" variants of carbonic anhydrase-1 (CA1), adenylate kinase (AK) and esterase D (ESD) were discovered with remarkably high frequencies. The variant CAS1 isozyme discovered among the Mamanwa tribe of northeastern Mindanao was electrophoretically indistinguishable from the "Guam" variant. Subsequent study of peptide mapping and amino acid analysis showed that they are in fact identical. The frequency of the variant allele was estimated at 0.20-0.25. The AK variant had an estimated frequency of 0.07 among the Aeta of Luzon. The fact that these variants occur sporadically in wide areas in the western Pacific suggests that they have been spread by gene diffusion from the aboriginal populations of this area, from which the present Negrito probably are derived.

Adenylate Kinase↗
PubMed1980

The high prevalence of Wuchereria bancrofti infections in indigenous tribes in northern Mindanao, Philippines.

Human filariasis was detected in an anthropological and medical survey among the indigenous Mamanwa people of the northernmost region of Mindanao, Philippines in specimens of thin blood smears and cultures of leucocytes from blood samples taken in the day time in September, 1978. Microfilaria positives were 23.2% (22/95) at Bo. Pangaylan, Santiago, 26.7% (28/105) at Kitcharao, Agusan del Norte, 19.3% (16/83) at Urbistondo, Surigao del Norte, Mindanao and none (0/50) at Abucay, Bataan, Luzon. Morphological characteristics of microfilaria were those of Wuchereria bancrofti. The periodicity of microfilaria observed in 3 Mamanwa people was nocturnally periodic with the peak hours at 12 o'clock midnight and the periodicity index at 124.4 following the method of Aikat & Das, or 92.35 following the method of Sasa & Tanaka. Microfilaria positives in the culture of leucocytes were as high as 41.2% (28/68). Since blood samples were taken in the day time and the filaria in these areas was nocturnally periodic, the prevalence of infection among these people is assumed to be much higher than the observed prevalence.

Adolescent↗
PubMed1979

Polymorphism of red cell glutamic-pyruvic transaminase in Japanese: gene frequencies in samples from Northern Japan.

The genetic polymorphism of red cell GPT was investigated by starch-gel electrophoresis in four samples from northern Japan including a sample of the Ainu of Hokkaido. The distribution of the Gpt1 gene frequencies among 10 samples excluding the Ainu so far examined showed heterogeneity. The geographical cline of Gpt1 gene frequency reported in southern Japan was not observed in northern Japan.

Adult↗
PubMed1979

Carbonic anhydrase-I polymorphism in a Philippine aboriginal population.

Polymorphism of carbonic anhydrase-I (CA1) was found by electrophoresis in an aboriginal group of Mindanao, Philippines, with a remarkably high frequency of variant types. The frequency of the variant allele was estimated at .256. The variant isozyme designated CA1 3Negrito (CA1 3N) is electrophoretically indistinguishable from the "Guam" variant and may be regarded as a potential anthropological marker in the Western Pacific.

Black People↗
PubMed1979

Population genetic studies of the Philippine Negritos. II. gm and km allotypes of three population groups.

Serum samples of the three tribal Negrito populations in the Philippine Islands (127 from Zambales, 87 from Bataan, and 93 from Agusan) were tested for Glm(1,2,3 and 17), and G3m(5,6,11,13,14,15,16, and 21), and Km(1). The GMpatterm of the Negritos is characterized by three haplotypes, Gm1,17;21, Gm1,2,17;21, and Gm1,3;5,11,13,14, which is also characteristic of Mongoloid-related populations, especially with high incidence of the latter haplotype. They also have the haplotype, Gm1,17;5,13,14, prevalent in Africa, New Guinea, and northern Australia, suggesting an ancient link between the Negritos and the New Guinean-Australian group. Two unusual samples of G3m(15) positive without G3m(16) observed in Zambales Negritos suggest the presence of Gm1,17;5,11,13,14,15 haplotype in the population. This appears to be unique to Zambales Negritos and the first such samples to be found.

Alleles↗
PubMed1978

Population genetic studies of the Philippine Negritos. I. A pilot survey of red cell enzyme and serum protein groups.

Electrophoretic surveys of red cell enzyme and serum protein systems representing 21 genetic loci were carried out on 129 blood samples of the Negritos of Pampanga, Central Luzon, the Philippines. Nine (out of 16) red cell enzyme loci and four (out of five) serum protein loci showed polymorphic variation. Low frequencies of ACP 1A, GPTs1, ESD2, and Hp1, and a markedly high frequency of PGM12 were contrasted to those in non-Negrito Filipinos. Variant ESD phenotypes with a slowly migrating isozyme occurred in high frequency. The new allele designated as ESD3Negrito (ESD3N) had a frequency of .10 +/- .019. In AK, a variant phenotype indistinguishable from AK 2-1 was observed in 14% of the sample. In the Gc system, a fast migrating variant was discovered in high frequency which was distinct from Gc Ab and Gc J. The variant allele, denoted GcNegrito (GcN), had a frequency of .21 +/- .025. A relatively high degree of allelic diversity in the Negrito sample was also suggested by the average heterozygosity for 21 loci screened (.165), which is compared to that of the Japanese population (.140).

Black People↗