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B Arce-Gomez

Publications and source records attributed to B Arce-Gomez.

10 recordsLinked to original sources
PubMed1989

HLA-A29 and genetic susceptibility to chromoblastomycosis.

The distribution of 12 HLA-A, 14 HLA-B, seven HLA-C, seven HLA-DR and three HLA-DQ antigens was determined in 32 non-consanguineous white Brazilians suffering from chromoblastomycosis and 77 healthy controls, matched for ethnic background, sex and age and living in the same geographical area. A significant difference between the two groups was seen only in respect to one HLA-A antigen: A29 was present in 28% of patients as opposed to 4% of the controls (P corrected = 0.03). This finding indicates that susceptibility to chromoblastomycosis may be influenced by a gene located on chromosome 6, in the region of the major histocompatibility complex. The relative risk for an HLA-A29 carrier to develop chromoblastomycosis was estimated as 10.

Adult↗
PubMed1988

Increased frequency of HLA-B40 in patients with paracoccidioidomycosis.

The presence of 9 HLA-A and 14 HLA-B specificities was determined in 83 patients with paracoccidioidomycosis. The finding of a higher than normal incidence of HLA-B40 (chi 2 = 10.8; corrected P less than 0.026) supports the hypothesis that genetic factors may play a role in susceptibility to paracoccidioidomycosis. The risk of developing paracoccidioidomycosis is 4.3 times higher for individuals carrying HLA-B40 than for those lacking this antigen.

Adult↗
PubMed1987

Association of viral hepatitis A with HLA-A9.

HLA-A and B phenotyping was carried out, during a viral hepatitis A (VHA) epidemic in Brazil, on 47 unrelated patients with VHA and 53 unrelated healthy subjects of the same age, sex, social status, and ethnic origin. An increased frequency of HLA-A9 (44.7% vs. 15.1%) and a decrease of that of HLA-A3 (2.1% vs. 22.6%) were observed when compared with controls. After correction for the number of antigens tested, only the positive association with HLA-A9 was observed. It was found that the relative risk for an HLA-A9 carrier to develop VHA was 4.5.

Adolescent↗
PubMed1987

Study on a Brazilian isolate. I. Population structure and random genetic drift.

A number of parameters were evaluated in order to determine the level of isolation of a small Brazilian community existing in partial geographic isolation and thereby evaluate the random genetic drift potential in the population. On a theoretical basis, it is concluded that the probability of genetic drift is low but cannot be excluded. The relatively small proportion of migrants (26%), the limited individual mobility, as given by marital distance (29 +/- 7 km), the mean migrational distance (46 +/- 11 km), the small effective size (122), and the value of the product Neme (26) agree with the possibility of genetic drift in this population. The observed coefficient of inbreeding (0.00239) is lower than that expected (0.0066) for random mating, suggesting some pressures against consanguineous marriage.

Adolescent↗
PubMed1987

Study on a Brazilian isolate. II. Opportunity for selection.

The opportunity for selection, measured by prereproductive mortality and fertility, was calculated for a small and relatively isolated Brazilian population. The total index of selection opportunity (0.53) was low in comparison to those obtained for other isolated populations. The contribution of prereproductive mortality (Im = 0.28) was 40% higher than that of fertility (If = 0.20).

Brazil↗
PubMed1978

The genetic control of HLA-A and B antigens in somatic cell hybrids: requirement for beta2 microglobulin.

The lymphoblastoid cell line Daudi lacks both HLA-A and B antigens and beta2 microglobulin. Somatic cell hybrids derived from a fusion between this line and D98/AH--2 were shown to express four HLA antigens not detectable on either parent cell, A1, A10(Aw26), Bw16(Bw38, Bw17. The initial definition by direct cytotoxicity assay was confirmed by absorption of reactions against target T lymphocytes, thus avoiding problems due to contaminating Ia antibodies, and by blocking the reactions by pretreatment with a chicken anti-human beta2 microglobulin serum. That the new specificities were due to the Daudi HLA region was confirmed by the finding that interspecific hybrids between Daudi and A9L, containing a single human chromosome 6, expressed A10 and Bw17. This also defined the haplotypes of Daudi as A10(Aw26), Bw17 and A1, Bw16(Bw38). The re-expression of the Daudi HLA-A and B antigens in two independent sets of hybrids indicates that it does not carry a mutation in the HLA region. It has previously been reported that somatic cell hybrids with Daudi, which contain chromosome 15, do not express human beta2 microglobulin. These results suggest that the reason for the lack of HLA-A and B antigens on Daudi is a secondary effect due to the mutation(s) in the beta2 microglobulin gene.

Beta-Globulins↗
PubMedDate not supplied

The HLA polymorphism in five Brazilian populations.

A total of 977 White individuals living in five Brazilian cities, as well as 173 Black individuals from two of these cities have been studied in relation to HLA-A and HLA-B. Allele frequency similarities among these populations are much more impressive than dissimilarities, and the differences, considering putative ancestors, are not remarkable. This limited variability can be only partially explained in terms of racial admixture, estimates of the latter using different alleles in the various populations showing disparate results. Linkage disequilibrium values vary between groups, that for A1-B8 being the most consistent, independent of sample or race. But four other haplotypes observed to be in significant disequilibrium in Portugal showed the same pattern in at least one of the five Brazilian White samples.

Adult↗