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Biomedical subjects

J E Bernal

Publications and source records attributed to J E Bernal.

33 records · Page 2Linked to original sources
PubMed1989

Polymorphism of serum proteins (C3, BF, HP and TF) of six populations in Colombia.

Five hundred and eighty-five serum samples from six populations in Colombia (Baranoa, Choco, Uitoto Indians, Subachoque, Pasto and Urban Bogotan) were investigated for four genetic markers. For the HP, C3 and BF systems but not for TF there is a wide range of gene frequency variation and these differences are compared with those in the few previous studies.

Black People↗
PubMed1988

Human lymphocyte antigen in actinic prurigo.

Thirty-one patients with actinic prurigo were human lymphocyte antigen (HLA)-typed. The results showed an association of this disease with the alleles B40 and Cw3, both usually found in linkage disequilibrium in most populations. Because these two antigens are more frequent in Amerindians than in whites, it is suggested that they may partly account for the restricted ethnic distribution of this disease.

Adult↗
PubMed1988

HLA antigens in the Uitoto Indians and an urban population of Colombia.

One hundred individuals from the city of Bogota and 32 Uitoto Indians from the Colombian Amazonia were HLA-typed. The results showed that the two populations differ significantly in the frequencies of the alleles A28, B15, B39, Bw51, Cw2, Cw3 and DRw52. In general, the Uitoto Indians resemble, in their histocompatibility antigens, other Latin-American Indians so far studied.

Colombia↗
PubMed1986

C3 variants and disease.

The distribution of C3 variants in dermatitis herpetiformis, thyroid cancer, spinal muscular atrophy, multiple sclerosis and psoriasis was studied, and also the Bf phenotype distribution in thyroid cancer. In thyroid cancer there was a significant deficit of heterozygotes for the C3 locus, a possible decrease in the C3F allele frequency and a significant elevation of frequency of the BfF allele. The possible involvement of these alleles in susceptibility to thyroid cancer appears worth further examination.

Alleles↗
PubMed1984

Genetic polymorphism of glutamate-pyruvate transaminase and glyoxalase I in Colombia.

Genetic polymorphism of red cell enzymes glutamate-pyruvate transaminase (GPT) and glyoxalase I (GLO) was investigated in five villages of the Colombian Andes. The GPT1 and GLO1 gene frequencies show a considerable range, but compatible to the range of European populations. In both the systems there is slight excess of observed homozygosity suggesting that the infrastructure of the subpopulations may be influenced by inbreeding.

Alanine Transaminase↗
PubMed1980

Cord serum AFP and the immunological status of the mother: a lack of correlation.

Cord serum from 139 newborns was analysed for alpha-fetoprotein and immunoglobulin G and the results correlated with the obstetric records of the mothers. No significant correlation was found in comparing either alpha-fetoprotein or immunoglobulin G levels with the previous obstetric experiences of the mothers. A previously reported sex difference of alpha-fetoprotein levels at birth was not found in this study. These results are discussed in the light of the possible immunosuppressive effects of alpha-fetoprotein.

Birth Weight↗
PubMed1979

C3 polymorphism in some Indian populations.

The distribution of C'3 phenotypes was studied in one tribal and three urban populations from India. The C'3F gene was found low in frequency compared to European and West Asian populations. Quantitatively also, the concentration of the C3 component in the Indian region was found significantly low to the European and West Asian populations reported previously.

Asia, Western↗
PubMedDate not supplied

Genetic and environmental influences on serum levels of human C4.

In a family study, levels of the C4 component of complement measured in 195 individuals show a continuous normal distribution. There is a slight but significant age effect, especially in females. Heritability is estimated at 62%. The effect of environment, however, remains substantial, and it is suggested that at some time during development the mechanism controlling the C4 levels establishes a general steady-state level whose effects remain after the divergence of sib environments with the approach of adulthood.

Adult↗
PubMedDate not supplied

Complement polymorphism in Colombia.

The polymorphism of complement component C3, BF and C4 was studied in an urban population of Bogota, Colombia and for C3 and BF, genetic heterogeneity was further examined among the five villages of the Colombian Andes. For both C3 and BF systems there is considerable variation of allele frequencies among the five villages and overall there is significant heterogeneity among the six population groups studied.

Alleles↗
PubMedDate not supplied

Haptoglobin subtypes among four different populations.

Haptoglobin subtypes were analysed by isoelectric focusing in four populations from Colombia, England, Nigeria, and India. There is a wide range of variation of allele frequencies in these four populations: HP*1S = 15-28%, HP*1F = 5-19%, HP*2FS = 54-79%. With the exception of the English, and the Spanish-speaking population of Colombia, all interpopulation comparisons showed significant heterogeneity. There is an extreme variation for the HP*1F allele in different populations, and a possible geographical cline of the HP*2FS allele increasing from west to east. The data presented here suggest that HP subtypes provide a useful anthropogenetic marker for racial differentiation.

Alleles↗
PubMedDate not supplied

HLA antigens in five Amerindian groups (Yuko, Bari, Tunebo, Guane and Paez) of Colombia: results of 'Expedición Humana'.

The serological HLA types (A, B, C and D loci) were studied in five different Indian groups in Colombia. The range of polymorphism was not very restricted in these groups, but there was significant genetic heterogeneity among the five populations in all the HLA loci. The gene frequency data, when converted into a kinship matrix and a two-dimensional eigen vector plot, showed a closer affinity between Bari and Yuko Indians, while Guane, Tunebo and Paez Indians were not only genetically different from the former but also well-differentiated from each other. It seems therefore from this study that geographical proximity may play a greater role than linguistic similarities in the genetic affinities of Colombian Amerindians.

Antigenic Variation↗