Data related to ten protein genetic loci expressed in blood obtained from four South American bla... more Data related to ten protein genetic loci expressed in blood obtained from four South American black populations were compared with data from seven African countries. Estimates of admixture among South American blacks were revised, and several indexes of gene diversity and genetic distances between the 11 populations were calculated. The admixture values and genetic relationships observed among the South American black communities conform well with those expected on historical grounds, and they show only moderate reductions in genetic diversity.
Abstract. The genetic variation at the Apolipoprotein E locus (APOE) is an important determinant ... more Abstract. The genetic variation at the Apolipoprotein E locus (APOE) is an important determinant of plasma lipids and has been implicated in various human pathological conditions. The objective of the present study was to estimate the distribution of APOE alleles in five Venezuelan communities: two Amerindian tribes (Bari and Yucpa), one Negroid population from Curiepe, one Caucasoid population from Colonia Tovar and the mestizo urban population living in Caracas. The APOE*3 allele was the most common allele in all populations studied. However, a significant increase in the APOE*2 allele frequency in the Mestizo (18.96%) and Negroid (16.25%) populations was found. Similar to results reported in other Native American populations we have found that the APOE*2 allele is completely absent in the Bari and Yucpa Amerindians. Frequencies found in the Colonia Tovar population are in agreement with those reported in the population of Germany, indicating a high degree of relatedness. The resu...
INTRODUCTION: For the purpose of the present paper we would like to classify the Waica as a subtr... more INTRODUCTION: For the purpose of the present paper we would like to classify the Waica as a subtribe of the Yanoama tribe, the ethnic identifica-tion and the internal composition of which appears to be but little understood. Although the actual blood group study will be ...
Tropical medicine and parasitology : official organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ), 1986
Studies on the immune function of patients with acute Plasmodium vivax or P. falciparum infection... more Studies on the immune function of patients with acute Plasmodium vivax or P. falciparum infections were performed. All subjects were residing in recent malaria endemic areas of Venezuela. Lymphopenia, reduction of peripheral blood T-lymphocytes positive for monoclonal antibody OKT4 (T helper) a decrease of in vitro mitogenic proliferative response and natural killer cell activity were observed. Serum lymphocytotoxic antibodies reactive at 37 degrees C were detected in both groups of patients as well as serum autoantibodies. The possible role of lymphocytotoxic autoantibodies in the etiology of the T-lymphocyte depletion and acquired immunological perturbations in human malaria is discussed.
The existence of splits of HLA-DR5 were not accepted during the Eighth Histocompatibility Worksho... more The existence of splits of HLA-DR5 were not accepted during the Eighth Histocompatibility Workshop, although some laboratories had claimed the existence of subsets [1]. At the present Workshop, difficulties in the distinction of DR5 from DRw6 and DRw8-related specificities led us to analyze several groups of sera differentiating these specificities. The segregation pattern of the sera mentioned in Table 1 were studied in informative families. Further details are given in the Joint Report on DRw6 (Schreuder et al., this volume). In brief, families were selected in which serum reactions appeared sufficiently strong and clearly segregated from parents to offspring. Such segregation patterns were termed haplotypes. Examples of such haplotypes are shown in Table 2. Several DR5-related patterns were observed in which all DRw52, DR5+w13 (6.6) and DR5+w8+w13 sera were positive. DR5 sera were invariably found positive in all haplotypes of patterns a, b, and c in Table 2.
This study represents the first report on the distribution of KIR genes in 205 unrelated healthy ... more This study represents the first report on the distribution of KIR genes in 205 unrelated healthy mestizo Venezuelan individuals. Genotyping analysis showed that all KIR genes are present in this population. Frequency of inhibitory killer cell immunoglobulin-like receptors (KIRs) exceeded 0.69, except for KIR2DL2 (0.29) and 2DL5 (0.37). Activating KIRs showed low frequencies (0.11-0.29), except for KIR2DS4 (0.68). Forty-five different KIR genotypes were identified, with a predominance of three genotypes found in 50.7% of the population of which 25.9% were individuals homozygous for haplotype A. The frequencies of KIR genes reflect the ethnic admixture existing in the mestizo Venezuelan population.
From the study of HLA, complement, and glyoxalase I alleles in 82 Venezuelan individuals belongin... more From the study of HLA, complement, and glyoxalase I alleles in 82 Venezuelan individuals belonging to 19 families of mixed ethnic origin having 20 affected newborns with salt-wasting congenital adrenal hyperplasia due to 21-hydroxylase (21-OH) deficiency, a total of 38 disease haplotypes and 53 nondisease haplotypes were found. Of the pathological haplotypes 47% were found to share the HLA-B39 or -Bw62 specificities, 55% of them in combination with the BFS, C2C, C4A4, C4B2 (SC42) complotype. The frequencies of HLA-B39 and -Bw62 among the affected haplotypes were 29 and 18% as compared with 6 and 0% among the nondisease haplotypes of the same families. Statistical associations (P less than 0.01) with salt-wasting adrenal hyperplasia were found with the SC42 complotype and with the combination SC42, HLA-B39. These results are markedly different from those reported in the literature which show an "association" at the population level among many Caucasoid samples of HLA-Bw47 and the extended haplotype (HLA-Bw47, DR7,FC91,0) with the salt-wasting form of the disease. Furthermore, four of the unrelated patients reported here were homozygous for all the major histocompatibility complex loci tested, while three others were homozygous for at least two HLA loci. Analysis of the geographical origin of the grandparents indicated clustering of the deficiency carrier HLA haplotypes. This observation, together with the fact that there is an excess of homozygotes among the patients in Venezuela, strongly suggests that salt-wasting 21-OH deficiency congenital adrenal hyperplasia is mostly the result of a founder effect of relatively hyperplasia is mostly the result of a founder effect identity by descent of a few abnormal alleles at the 21-OHB locus in most cases. The mutation marked by HLA-Bw47 was not observed in this population.
... J Med Gen 1982; 19:452454 10. Baur MP, Neugebauer M, Albert ED. Reference tables ot three-lcc... more ... J Med Gen 1982; 19:452454 10. Baur MP, Neugebauer M, Albert ED. Reference tables ot three-lccus haplotype frequencies and Delta valaes :n Cau-casians. Orientals and Negroids, In: Albert ED. Eaur MP, Mavr WR, eds. Histocompatibility Testing 19S4. ...
Immune reactivity indicators studied among 55 unrelated Venezuelan mestizo subjects included lymp... more Immune reactivity indicators studied among 55 unrelated Venezuelan mestizo subjects included lymphoproliferative response to polyclonal mitogen (PHA, Con A, PwM) stimulation, NK cell activity, and enumeration of peripheral blood mononuclear cells. HLA-A, -B, -C, -DR, and - ...
... The blood samples were analyzed for blood groups, haptoglobins, and hemo-globins. The haptogl... more ... The blood samples were analyzed for blood groups, haptoglobins, and hemo-globins. The haptoglobins and hemoglobins were studied by Dr Tulio Arends and will be published in detail elsewhere. ... Anti-K, and anti-k for the Kell system Anti-Lea for the Lewis system ...
Gene geography : a computerized bulletin on human gene frequencies
Twenty-one genetic systems were investigated in three relatively isolated South American Black po... more Twenty-one genetic systems were investigated in three relatively isolated South American Black populations. Unexpected allele frequencies were found in different systems in all populations, suggesting the occurrence of genetic drift and/or founder effects. The estimates of racial admixture indicate 50% to 79% of Black ancestry, with various degrees of White (18%-28%) and Amerindian (3%-32%) ancestry.
The production and characterization of 21 monoclonal antibodies (MoAbs) resulting from the immuni... more The production and characterization of 21 monoclonal antibodies (MoAbs) resulting from the immunization of Balb/c mice with human lymphoblastoid cell lines is reported. Twelve MoAbs seem to be detecting an HLA polymorphic determinant. Four MoAbs are recognizing monomorphic Class I molecules and another MoAb detects HLA Class II molecules. These results were confirmed by ELISA, cytotoxicity, immunofluorescence and immunoprecipitation. Class and subclass of the MoAbs were assessed by Ouchterlony analysis. Twenty two T cell clones were additionally generated by limiting dilution of lymphocytes stimulated by allogeneic peripheral blood lymphocytes on mixed lymphocyte cultures. Five of these clones were characterized, testing each one for its ability to proliferate in response to a panel of lymphoblastoid cell lines. It was found that they detect the HLA-A9, A23, A29-31, Bw62 and DR7 specificities respectively. These results indicate that the generation of cellular monoclonal reagents is...
Data related to ten protein genetic loci expressed in blood obtained from four South American bla... more Data related to ten protein genetic loci expressed in blood obtained from four South American black populations were compared with data from seven African countries. Estimates of admixture among South American blacks were revised, and several indexes of gene diversity and genetic distances between the 11 populations were calculated. The admixture values and genetic relationships observed among the South American black communities conform well with those expected on historical grounds, and they show only moderate reductions in genetic diversity.
Abstract. The genetic variation at the Apolipoprotein E locus (APOE) is an important determinant ... more Abstract. The genetic variation at the Apolipoprotein E locus (APOE) is an important determinant of plasma lipids and has been implicated in various human pathological conditions. The objective of the present study was to estimate the distribution of APOE alleles in five Venezuelan communities: two Amerindian tribes (Bari and Yucpa), one Negroid population from Curiepe, one Caucasoid population from Colonia Tovar and the mestizo urban population living in Caracas. The APOE*3 allele was the most common allele in all populations studied. However, a significant increase in the APOE*2 allele frequency in the Mestizo (18.96%) and Negroid (16.25%) populations was found. Similar to results reported in other Native American populations we have found that the APOE*2 allele is completely absent in the Bari and Yucpa Amerindians. Frequencies found in the Colonia Tovar population are in agreement with those reported in the population of Germany, indicating a high degree of relatedness. The resu...
INTRODUCTION: For the purpose of the present paper we would like to classify the Waica as a subtr... more INTRODUCTION: For the purpose of the present paper we would like to classify the Waica as a subtribe of the Yanoama tribe, the ethnic identifica-tion and the internal composition of which appears to be but little understood. Although the actual blood group study will be ...
Tropical medicine and parasitology : official organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ), 1986
Studies on the immune function of patients with acute Plasmodium vivax or P. falciparum infection... more Studies on the immune function of patients with acute Plasmodium vivax or P. falciparum infections were performed. All subjects were residing in recent malaria endemic areas of Venezuela. Lymphopenia, reduction of peripheral blood T-lymphocytes positive for monoclonal antibody OKT4 (T helper) a decrease of in vitro mitogenic proliferative response and natural killer cell activity were observed. Serum lymphocytotoxic antibodies reactive at 37 degrees C were detected in both groups of patients as well as serum autoantibodies. The possible role of lymphocytotoxic autoantibodies in the etiology of the T-lymphocyte depletion and acquired immunological perturbations in human malaria is discussed.
The existence of splits of HLA-DR5 were not accepted during the Eighth Histocompatibility Worksho... more The existence of splits of HLA-DR5 were not accepted during the Eighth Histocompatibility Workshop, although some laboratories had claimed the existence of subsets [1]. At the present Workshop, difficulties in the distinction of DR5 from DRw6 and DRw8-related specificities led us to analyze several groups of sera differentiating these specificities. The segregation pattern of the sera mentioned in Table 1 were studied in informative families. Further details are given in the Joint Report on DRw6 (Schreuder et al., this volume). In brief, families were selected in which serum reactions appeared sufficiently strong and clearly segregated from parents to offspring. Such segregation patterns were termed haplotypes. Examples of such haplotypes are shown in Table 2. Several DR5-related patterns were observed in which all DRw52, DR5+w13 (6.6) and DR5+w8+w13 sera were positive. DR5 sera were invariably found positive in all haplotypes of patterns a, b, and c in Table 2.
This study represents the first report on the distribution of KIR genes in 205 unrelated healthy ... more This study represents the first report on the distribution of KIR genes in 205 unrelated healthy mestizo Venezuelan individuals. Genotyping analysis showed that all KIR genes are present in this population. Frequency of inhibitory killer cell immunoglobulin-like receptors (KIRs) exceeded 0.69, except for KIR2DL2 (0.29) and 2DL5 (0.37). Activating KIRs showed low frequencies (0.11-0.29), except for KIR2DS4 (0.68). Forty-five different KIR genotypes were identified, with a predominance of three genotypes found in 50.7% of the population of which 25.9% were individuals homozygous for haplotype A. The frequencies of KIR genes reflect the ethnic admixture existing in the mestizo Venezuelan population.
From the study of HLA, complement, and glyoxalase I alleles in 82 Venezuelan individuals belongin... more From the study of HLA, complement, and glyoxalase I alleles in 82 Venezuelan individuals belonging to 19 families of mixed ethnic origin having 20 affected newborns with salt-wasting congenital adrenal hyperplasia due to 21-hydroxylase (21-OH) deficiency, a total of 38 disease haplotypes and 53 nondisease haplotypes were found. Of the pathological haplotypes 47% were found to share the HLA-B39 or -Bw62 specificities, 55% of them in combination with the BFS, C2C, C4A4, C4B2 (SC42) complotype. The frequencies of HLA-B39 and -Bw62 among the affected haplotypes were 29 and 18% as compared with 6 and 0% among the nondisease haplotypes of the same families. Statistical associations (P less than 0.01) with salt-wasting adrenal hyperplasia were found with the SC42 complotype and with the combination SC42, HLA-B39. These results are markedly different from those reported in the literature which show an "association" at the population level among many Caucasoid samples of HLA-Bw47 and the extended haplotype (HLA-Bw47, DR7,FC91,0) with the salt-wasting form of the disease. Furthermore, four of the unrelated patients reported here were homozygous for all the major histocompatibility complex loci tested, while three others were homozygous for at least two HLA loci. Analysis of the geographical origin of the grandparents indicated clustering of the deficiency carrier HLA haplotypes. This observation, together with the fact that there is an excess of homozygotes among the patients in Venezuela, strongly suggests that salt-wasting 21-OH deficiency congenital adrenal hyperplasia is mostly the result of a founder effect of relatively hyperplasia is mostly the result of a founder effect identity by descent of a few abnormal alleles at the 21-OHB locus in most cases. The mutation marked by HLA-Bw47 was not observed in this population.
... J Med Gen 1982; 19:452454 10. Baur MP, Neugebauer M, Albert ED. Reference tables ot three-lcc... more ... J Med Gen 1982; 19:452454 10. Baur MP, Neugebauer M, Albert ED. Reference tables ot three-lccus haplotype frequencies and Delta valaes :n Cau-casians. Orientals and Negroids, In: Albert ED. Eaur MP, Mavr WR, eds. Histocompatibility Testing 19S4. ...
Immune reactivity indicators studied among 55 unrelated Venezuelan mestizo subjects included lymp... more Immune reactivity indicators studied among 55 unrelated Venezuelan mestizo subjects included lymphoproliferative response to polyclonal mitogen (PHA, Con A, PwM) stimulation, NK cell activity, and enumeration of peripheral blood mononuclear cells. HLA-A, -B, -C, -DR, and - ...
... The blood samples were analyzed for blood groups, haptoglobins, and hemo-globins. The haptogl... more ... The blood samples were analyzed for blood groups, haptoglobins, and hemo-globins. The haptoglobins and hemoglobins were studied by Dr Tulio Arends and will be published in detail elsewhere. ... Anti-K, and anti-k for the Kell system Anti-Lea for the Lewis system ...
Gene geography : a computerized bulletin on human gene frequencies
Twenty-one genetic systems were investigated in three relatively isolated South American Black po... more Twenty-one genetic systems were investigated in three relatively isolated South American Black populations. Unexpected allele frequencies were found in different systems in all populations, suggesting the occurrence of genetic drift and/or founder effects. The estimates of racial admixture indicate 50% to 79% of Black ancestry, with various degrees of White (18%-28%) and Amerindian (3%-32%) ancestry.
The production and characterization of 21 monoclonal antibodies (MoAbs) resulting from the immuni... more The production and characterization of 21 monoclonal antibodies (MoAbs) resulting from the immunization of Balb/c mice with human lymphoblastoid cell lines is reported. Twelve MoAbs seem to be detecting an HLA polymorphic determinant. Four MoAbs are recognizing monomorphic Class I molecules and another MoAb detects HLA Class II molecules. These results were confirmed by ELISA, cytotoxicity, immunofluorescence and immunoprecipitation. Class and subclass of the MoAbs were assessed by Ouchterlony analysis. Twenty two T cell clones were additionally generated by limiting dilution of lymphocytes stimulated by allogeneic peripheral blood lymphocytes on mixed lymphocyte cultures. Five of these clones were characterized, testing each one for its ability to proliferate in response to a panel of lymphoblastoid cell lines. It was found that they detect the HLA-A9, A23, A29-31, Bw62 and DR7 specificities respectively. These results indicate that the generation of cellular monoclonal reagents is...
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