RESUMO
OBJECTIVES: The aim of this study was to contribute to the knowledge of pre-Hispanic Andean mitochondrial diversity by analyzing an individual from the archaeological site Pukara de La Cueva (North-western Argentina). The date of the discovery context (540 ± 60 BP) corresponds to the Regional Developments II period. METHODS: Two separate DNA extractions were performed from dentin powder of one tooth. HVR I was amplified by PCR from each extract in three overlapping fragments and the haplotype was determined by consensus among all obtained sequences. The procedures were carried out under strict protocols developed for working with ancient DNA. RESULTS: The individual belonged to the A2ah lineage due to the presence of the 16097C and 16098G transitions, which constitute its distinctive motif. This lineage is very rare in Native American populations and was described in four individuals from current groups inhabiting the Bolivian Llanos, two from South-eastern Brazil, and one from the Gran Chaco region. In addition, two other mutations (16260T and 16286T) were shared with one of the individuals from the Bolivian Llanos region. CONCLUSIONS: Considering that the origin of this lineage was postulated for the South American lowlands, the present pre-Hispanic discovery in the Andean area could be taken as a new evidence of gene flow between these regions. Also, it allows the questioning of the geographical origin of this mitochondrial lineage.
Assuntos
Fluxo Gênico , Variação Genética , Haplótipos , Indígenas Sul-Americanos/genética , Adolescente , Adulto , Arqueologia , Argentina , Criança , Pré-Escolar , DNA Mitocondrial/análise , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
The city of Bahía Blanca occupies a strategic place in Argentina south of the Pampean region in the north-east corner of the Patagonia. Since 1828, this city has been the historical and political border between Amerindian lands in the south, and the lands of European colonists. Nowadays, Bahía Blanca is an urban population mainly composed by descendents of immigrants from Spain and other European countries with apparently low admixture with Amerindians. In view of the unexpectedly high Amerindian admixture levels (about 46.7%) suggested by mtDNA data, and protein markers (19.5%), we analyzed a set of 19 Alu polymorphisms (18 autosomal, 1 of Chromosome Y) in a well-documented genealogical sample from Bahía Blanca. The genotyped sample was made up of 119 unrelated healthy individuals whose birth place and grandparent origins were fully documented. According to available genealogical records, the total sample has been subdivided into two groups: Bahía Blanca Original (64 individuals with all 4 gandparents born in Argentina) and Bahía Blanca Mix (55 individuals with one to three grandparents born out of Argentina). Allele frequencies and gene diversity values in Bahía Blanca fit well into the European ranges. Population relationships have been tested for 8 Alu markers, whose variation has been described in several Amerindian and European samples. Reynolds genetic distances underline the significant genetic similarity of Bahía Blanca to Europeans (mean distance 0.044) and their differentiation from Amerindians (0.146). Interestingly enough, when the general sample is divided, Bahía Blanca Original appears slightly closer to Amerindians (0.127) in contrast to Bahía Blanca Mix (0.161). Furthermore, the genetic relationships depicted through a principal components analysis emphasize the relative similarity of Bahía Blanca Original to Amerindians. A thorough knowledge of the sample origins has allowed us to make a subtle distinction of the genetic composition of Bahía Blanca.
Assuntos
Elementos Alu/genética , Variação Genética/genética , Genética Populacional , Indígenas Sul-Americanos/genética , Polimorfismo Genético/genética , Adulto , Argentina , Emigração e Imigração , Europa (Continente)/etnologia , Feminino , Frequência do Gene/genética , Humanos , Indígenas Sul-Americanos/etnologia , Masculino , População UrbanaRESUMO
New data on 17 blood group and protein genetic systems obtained among the Ayoreo and Lengua Indians of Paraguay are presented. They include the first report on the red cell band-3 protein investigated among South American Indians. This information was integrated with previous results available for these two and four other groups. Five of the six populations reside in the Chaco area, while the sixth was included as an outgroup living elsewhere in Paraguay. Four of the five Chaco tribes exhibit good genetic homogeneity, but the Ayoreo are somewhat different. The results confirm the Chaco as a distinct biological (as well as cultural and economic) region, which should be considered in evaluations of genetic variability among South American Indians.
Assuntos
Antígenos de Grupos Sanguíneos/genética , Proteínas Sanguíneas/genética , Variação Genética , Indígenas Sul-Americanos , Alelos , Distribuição de Qui-Quadrado , Frequência do Gene , Haplótipos , Humanos , Método de Monte Carlo , Paraguai , Fenótipo , Polimorfismo GenéticoRESUMO
A total of 495 individuals from five different Argentinian tribes was examined for variation in 23 blood group and protein genetic systems, and the results were integrated with previous data on some of these systems. These tribes generally present RH * R1, PGM1 * 1, and ACP * A frequencies lower and RH * R2, ESD * 1, and GLO * 1 prevalences higher than those observed in other South American Indian groups. Earlier studies with mitochondrial DNA showed that haplogroup A was present in low frequencies in these tribes, but haplogroup B showed a high prevalence among the Mataco. Average heterozygosities are very similar in the five tribes, while estimates of non-Indian ancestry are generally low. Both the blood group and protein, as well as the mtDNA data sets, divide the five tribes into two groups, and the relationships obtained with the blood group and protein systems are exactly those expected on the basis of geography and language. However, the topology obtained with the mtDNA results was different, possibly due to sampling effects or diverse patterns of exchange between the groups related to sex.
Assuntos
DNA Mitocondrial/genética , Frequência do Gene , Indígenas Norte-Americanos/genética , Argentina , Teste de Histocompatibilidade , Humanos , Proteínas/genéticaRESUMO
We report the distribution of the APOB signal peptide polymorphism in 5 native populations of South America: 2 samples of Mataco and 1 sample each of Pilagá and Toba from the Argentinian Chaco and 1 sample of Ache from the Paraguay forest. A randomly selected subsample of a previously studied sample from the Cayapa of Ecuador (Scacchi et al. 1997) was reanalyzed to investigate probable differences attributable to sampling, laboratory techniques, or interobserver error. The polymorphism observed in the signal peptide region of the APOB gene among native populations of South America exhibits the same range of variation found among geographic continental populations, confirming the high genetic heterogeneity of South Amerindians. Extremes in the allele prevalences were found among the Mataco and Ache, populations not far apart geographically. The small differences in genotype and allele frequencies between the subsample of the Cayapa analyzed here and the original Cayapa sample and between the 2 Mataco samples were not statistically significant and most likely were due to sampling error.
Assuntos
Apolipoproteínas B/genética , Variação Genética/genética , Indígenas Sul-Americanos/genética , Polimorfismo Genético/genética , Sinais Direcionadores de Proteínas/genética , Alelos , Argentina , Viés , Frequência do Gene/genética , Heterogeneidade Genética , Genótipo , Humanos , ParaguaiRESUMO
We have studied the hypervariable D1S80 locus in 185 individuals from five South American Indian tribes, integrating these results with previous investigations. Three alleles (*18, *24 and *30) were common to all tribes, but their frequencies varied between northern and southern populations. Brazilian tribes have a high frequency of *30 (average 35%) while in Argentinian and Chilean Indian populations this allele is present, on average, in 7% of the chromosomes only. Allele *24, the most common in other ethnic groups, was observed in 10% and 25% of northern and southern Amerindians respectively. Genetic distance and dendrogram analyses placed the Argentinian and Chilean tribes closer to Brazilian Caucasians, suggesting non-Indian admixture among them.
Assuntos
Alelos , Variação Genética , Indígenas Sul-Americanos/genética , Análise de Variância , Mapeamento Cromossômico , Frequência do Gene/genética , Genética Populacional , Humanos , Repetições MinissatélitesRESUMO
Hemolytic uremic syndrome (HUS) is a serious problem in Argentina, where 50% of the known cases are reported to come from. In the so-called "typical" HUS, anemia, thrombocytopenia and acute renal failure are usually preceded by an episode of infection. Many agents such as bacteria, toxins and viruses have been linked with the prodromal episode, but the reason for the occurrence of HUS in only a small portion of individuals with identical previous symptoms, is not clear. The hypothesis of a particular immune response modifying the susceptibility of some hosts to develop the syndrome after an otherwise well tolerated infection is not formally excluded. The aim of our work was to explore some immunological parameters in order to add more data concerning the immunologic changes occurring during the acute phase of HUS in 24 pediatric patients. We coincide with previous authors on the normal values of serum complement levels and the increase of IgG, IgA and IgM concentrations. (Table 1). We also report a significant and transient decrease in the percentage of T lymphocytes and an increase in the relative number of B lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Linfócitos B/imunologia , Síndrome Hemolítico-Urêmica/imunologia , Células Matadoras Naturais/imunologia , Linfócitos T/imunologia , Relação CD4-CD8 , Pré-Escolar , Proteínas do Sistema Complemento/análise , Feminino , Humanos , Imunidade Celular , Imunoglobulinas/análise , Lactente , Contagem de Leucócitos , Masculino , Muromonab-CD3 , Estudos ProspectivosRESUMO
Hemolytic uremic syndrome (HUS) is a serious problem in Argentina, where 50
of the known cases are reported to come from. In the so-called [quot ]typical[quot ] HUS, anemia, thrombocytopenia and acute renal failure are usually preceded by an episode of infection. Many agents such as bacteria, toxins and viruses have been linked with the prodromal episode, but the reason for the occurrence of HUS in only a small portion of individuals with identical previous symptoms, is not clear. The hypothesis of a particular immune response modifying the susceptibility of some hosts to develop the syndrome after an otherwise well tolerated infection is not formally excluded. The aim of our work was to explore some immunological parameters in order to add more data concerning the immunologic changes occurring during the acute phase of HUS in 24 pediatric patients. We coincide with previous authors on the normal values of serum complement levels and the increase of IgG, IgA and IgM concentrations. (Table 1). We also report a significant and transient decrease in the percentage of T lymphocytes and an increase in the relative number of B lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)
RESUMO
Argentine Hemorrhagic Fever manifests itself in man either subclinically or in hemorrhagic or neurological forms, mortality reaching 20%. Although Candid 1 strain is undergoing pilot trials, current therapy still resorts to convalescent serum administration. A neurological model was used to evaluate protection conferred by the attenuated XJC13 Junin virus strain. Newborn rats inoculated intraperitoneally (ip) prove resistant, whereas 8-12 day-old animals infected by intracerebral route with the XJ prototype strain suffer 100% mortality with neurological signs. The aim of this study was to achieve protection in this model and attempt to elucidate the mechanisms involved in resistance. It was observed that the longer the inoculation challenge interval, the greater was the survival percentage. In protected animals, brain viral titres were 3 log lower than in challenged controls, while XJC13 infected unchallenged controls presented low CNS values throughout. Neutralizing antibody levels were not significantly different in experimental versus challenged control groups, ruling out any secondary booster effect on protected rats. Neither the transfer of immunoserum nor of endogenous or exogenous interferon altered mortality. However, when splenocytes from rats infected 10 days previously were transferred prior to XJ challenge, survival was increased to 50%, but there was no gain in protection when cells were treated with antithymocyte serum plus complement. Consequently, protection in this neurological model can be attributed to a cellular immune response.