Resumo: Grupos linguísticos Tupí exibem uma grande dispersão geográfica na América do Sul, provavelmente originadas, conforme apontada pela linguistica, na Região Madeira-Guaporé (MGR), Brasil. O presente estudo revisou dados geneticos de populacoes Tupí para marcadores autossomicos e uniparentais (Y-cromossomo and mtDNA), delineando abordagens para avaliar origem geográfica, bem como a dinâmica demográfica de sua dispersão, de um ponto de vista genético. Comparação da variabilidade genetica e das frequencias do haplogrupo D do mtDNA sugere um cenário onde MGR é o local de origem Tupí. A relação entre cinco estimadores de variabilidade genetica Thetas-S, -Pi, -m2, -H e -k) mostram que grupos Tupí da MGR não MGR experienciaram diferentes padrões de dinâmica demográfica, com uma antiga expansão Tupí em MGR, seguida de dispersão para outras regiões da América do Sul, provavelmente associada a eventos de depopulação/efeito fundador. Além disso, outros eventos recentes de depopulação também puderam ser detectados em ambas as regiões. Finalmente, a dispersão parece estar relacionada com práticas de patrilocalidade, como sugerido pela comparação de marcadores uniparentais. Este modelo genético de dinâmica de dispersão Tupí pode ter um impacto importante na interpretação dos dados arqueológicos e linguísticos, permitindo testar se tecnologias associadas ao sexo feminino, como a cerâmica, são mais amplamente compartilhadas entre populações dispersas do que tecnologias 1não exclusivas do sexo feminino.

Abstract: Tupí linguistic groups display a wide geographical dispersion in South America, probably originated, as pointed by linguistic, from Madeira-Guaporé Region (MGR) in Brazil. The present study reviewed genetic data on Tupians for autosomal and uniparental (Y-chromosome and mtDNA) markers, using it to evaluate Tupians geographic origin as well as the demographic dynamics of their dispersion from a genetic point of view. Comparison of genetic variability and mtDNA haplogroups D frequencies suggests a scenario where MGR is the Tupí homeland. The relationship between five estimators of genetic variability (Thetas-S, -Pi, -m2, -H and -k) shows that Tupí groups from MGR and non-MGR experienced different patterns of demographic dynamics, with an ancient Tupí expansion in MGR, followed by dispersion to other South America regions, probably associated to depopulation/founder effect events. Furthermore, other recent depopulation events could also be detected in both regions. Finally, the dispersion seems to be related to patrilocality, as suggested by comparison of uniparental markers genetic differentiation. This genetic model of dispersion dynamics may have an important impact in the interpretation of archeological and linguistic data, allowing to test if female associated technologies, like ceramic, are more extensively shared between dispersed populations than those which are not female-exclusive.

Soroprevalence for Hepatitis C virus is reported as 2.12% in Northern Brazil, with about 50% of the patients exhibiting a sustained virological response (SVR). Aiming to associate polymorphisms in Killer Cell Immunoglobulin-like Receptors (KIR) with chronic hepatitis C and therapy responses we investigated 125 chronic patients and 345 controls. Additionally, 48 ancestry markers were genotyped to control for population stratification. The frequency of the KIR2DL2 and KIR2DL2+HLA-C Asp80 gene and ligand was higher in chronic infected patients than in controls (p < 0.0009, OR = 3.4; p = 0.001, OR = 3.45). In fact, KIR2DL3 is a weaker inhibitor of NK activity than KIR2DL2, which could explain the association of KIR2DL2 with chronic infection. Moreover, KIR2DS2 and KIR2DS2+HLA-C Asp80 (p < 0.0001, OR = 2.51; p = 0.0084, OR = 2.62) and KIR2DS3 (p < 0.0001; OR = 2.57) were associated with chronic infection, independently from KIR2DL2. No differences in ancestry composition were observed between control and patients, even with respect to therapy response groups. The allelic profile KIR2DL2/KIR2DS2/KIR2DS3 was associated with the chronic hepatitis C (p < 0.0001; OR = 3). Furthermore, the patients also showed a higher mean number of activating genes and a lower frequency of the homozygous AA profile, which is likely secondary to the association with non-AA and/or activating genes. In addition, the KIR2DS5 allele was associated with SVR (p = 0.0261; OR = 0.184).The ancestry analysis of samples ruled out any effects of population substructuring and did not evidence interethnic differences in therapy response, as suggested in previous studies.

INTRODUÇÃO: No Brasil, estudos mostram que a soroprevalência do HTLV entre gestantes varia de 0 a 1,8%. Contudo, esta soroprevalência era desconhecida no Estado do Pará, Brasil. O presente estudo descreve, pela primeira vez, a soroprevalência do HTLV entre gestantes do Estado do Pará, Norte do Brasil. MÉTODOS: 13,382 gestantes foram submetidas à triagem para HTLV durante o pré-natal, e aquelas com sorologia alterada para anti-HTLV foram submetidas ao teste de Western Blot (WB), para confirmar e discriminar portadoras do HTLV-1 e do HTLV-2. RESULTADOS: A soroprevalência do HTLV na população de gestantes foi de 0,3%, sendo o HTLV-1 identificado em 95,3% das pacientes. O perfil demográfico das portadoras do HTLV foi de: mulheres com idade entre 20-40 anos (78,4%); residentes na região metropolitana de Belém (67,6%) e com nível educacional igual ao ensino médio (56,8%). Outras variáveis relacionadas à infecção foram: início das relações sexuais compreendido entre 12-18 anos (64,9%), e ter sido aleitada mais de 6 meses (51,4%). A maior parte das mulheres estudadas teve ao menos duas gestações anteriores (35,1%); e nenhum aborto (70,3%). Co-infecções (sífilis e HIV) foram descritas em 10,8% (4/37) das gestantes. A soroprevalência da infecção pelo HTLV em gestantes atendidas em Unidades Básicas de Saúde do Estado do Pará, Norte do Brasil foi de 0,3% semelhante à descrita em outros estudos brasileiros. As variáveis relacionadas com a infecção são indicadores importantes na identificação de gestantes com maior tendência a soropositividade pelo HTLV, sendo uma estratégia de controle e prevenção, evitando a transmissão vertical.

INTRODUCTION: In Brazil, studies have shown that HTLV seroprevalence among pregnant women varies from 0 to 1.8%. However, this seroprevalence was unknown in the State of Pará, Brazil. The present study describes, for the first time, the HTLV seroprevalence among pregnant women from the State of Pará, Northern Brazil. METHODS: 13,382 pregnant women were submitted to HTLV screening during prenatal care, and those with non-seronegative results to anti-HTLV were submitted to Western blot (WB) test to confirm and separate HTLV-1 and HTLV-2 carriers. RESULTS: HTLV seroprevalence in the population of pregnant women was 0.3%, and HTLV-1 was identified in 95.3% of patients. The demographic profile of HTLV carriers was as follows: women with age between 20 and 40 years old (78.4%); residing in the metropolitan region of Belém, Pará (67.6%); and with educational level of high school (56.8%). Other variables related to infection were as follows: beginning of sexual intercourse between the age of 12 and 18 years old (64.9%) and have being breastfed for more than 6 months (51.4%). Most of the women studied had at least two previous pregnancies (35.1%) and no abortion (70.3%). Coinfections (syphilis and HIV) were found in 10.8% (4/37) of these pregnant women. CONCLUSIONS: Seroprevalence of HTLV infection in pregnant women assisted in basic health units from the State of Pará, Northern Brazil, was 0.3% similar to those described in other Brazilian studies. The variables related to infection were important indicators in identifying pregnant women with a higher tendency to HTLV seropositivity, being a strategy for disease control and prevention, avoiding vertical transmission.

Host genetic factors play an important role in mediating resistance to HIV-1 infection and may modify the course of infection. HLA-B alleles (Bw4 epitope; B*27 and B*57) as well as killer cell immunoglobulin-like receptors have been associated with slow progression of HIV-1 infection. OBJECTIVE: To evaluate the association between serological epitopes HLA-Bw4 and HLA-Bw6 and prognostic markers in AIDS. METHODS: 147 HIV-infected individuals in Bahia, Northeast Brazil, were genotyped for HLA class I locus. HLA class I genotyping was performed by hybridization with sequence-specific oligonucleotide probes following amplification of the corresponding HLA-A, HLA-B and HLA-C genes. Statistical analysis was performed using Fisher's exact and ANOVA tests for categorical and continuous variables, respectively. RESULTS: We detected a significant association (χ2 = 4.856; p = 0.018) between the presence of HLA-Bw4 and low levels of viremia. Eighteen out of the 147 HIV-infected individuals presented viremia <1,800 copies/mL and 129 presented viremia > 2,000 copies/mL. Ninety and four percent (17/18) of all individuals with viremia < 1,800 copies/mL carried HLA-Bw4, compared to 67.4% (87/129) of individuals with viremia > 2,000 copies/mL. Additionally, we found a significantly higher frequency of B*57 (OR = 13.94; 95% CI = 4.19-46.38; p < 0.0001) and Cw*18 (OR = 16.15; 95% CI = 3.46-75.43; p < 0.0001) alleles, favoring the group with lower viremia levels, in comparison with those with higher viral load. CONCLUSION: HLA-Bw4-B*57 and Cw*18 alleles are associated with lower level of viral load in HIV-infected Brazilian patients. These findings may help us in understanding the determinants of HIV evolution in Brazilian patients, as well as in providing important information on immune response correlates of protection for such population

The distribution of b-globin gene haplotypes was studied in 209 Amerindians from eight tribes of the Brazilian Amazon: Asurini from Xingú, Awá-Guajá, Parakanã, Urubú-Kaapór, Zoé, Kayapó (Xikrin from the Bacajá village), Katuena, and Tiriyó. Nine different haplotypes were found, two of which (n. 11 and 13) had not been previously identified in Brazilian indigenous populations. Haplotype 2 (+ - - - -) was the most common in all groups studied, with frequencies varying from 70% to 100%, followed by haplotype 6 (- + + - +), with frequencies between 7% and 18%. The frequency distribution of the b-globin gene haplotypes in the eighteen Brazilian Amerindian populations studied to date is characterized by a reduced number of haplotypes (average of 3.5) and low levels of heterozygosity and intrapopulational differentiation, with a single clearly predominant haplotype in most tribes (haplotype 2). The Parakanã, Urubú-Kaapór, Tiriyó and Xavante tribes constitute exceptions, presenting at least four haplotypes with relatively high frequencies. The closest genetic relationships were observed between the Brazilian and the Colombian Amerindians (Wayuu, Kamsa and Inga), and, to a lesser extent, with the Huichol of Mexico. North-American Amerindians are more differentiated and clearly separated from all other tribes, except the Xavante, from Brazil, and the Mapuche, from Argentina. A restricted pool of ancestral haplotypes may explain the low diversity observed among most present-day Brazilian and Colombian Amerindian groups, while interethnic admixture could be the most important factor to explain the high number of haplotypes and high levels of diversity observed in some South-American and most North-American tribes.

A região amazônica brasileira abriga diversas comunidades formadas por descendentes de escravos africanos, algumas das quais ainda relativamente isoladas. Nós estudamos duas dessas comunidades (Pacoval e Curiau), localizadas na área rural do município de Alenquer, Pará, e na região metropolitana de Macapá, Amapá, respectivamente. Entre os 12 loci investigados, alelos considerados como marcadores de ancestralidade africana, tais como HBB*S, HBB*C, TF*D1, HP*2M, ABO*B, RH*D- e CA2*2, foram encontrados com freqüências elevadas, de acordo com o esperado para populações com origem predominantemente africana. As estimativas de mistura racial indicaram que o percentual de contribuição africana em Curiau (74%) é maior do que em Pacoval (44%) e que em Curiau não foi detectada mistura com indígenas. As estimativas de ancestralidade africana estão de acordo com o grau de isolamento e com a mobilidade das comunidade estudadas. Pacoval apresenta um elevado percentual de imigrantes entre os pais e avós dos individuos estudados, enquanto que a comunidade de Curiau, apesar de situada na região metropolitana de Macapá, apresenta uma pequena proporção de imigrantes, sugerindo a existência de uma barreira relativamente forte contra a mistura interétnica. A análise dos dados genéticos foi também efetuada em sub-amostras constituídas apenas por indivíduos cujos pais e avós nasceram na localidade em estudo e que provavelmente representam essas populações duas gerações atrás. Os resultados indicaram que a mistura com não-negros nas duas populações não é um evento recente.

The Amazon region of Brazil includes communities founded by escaped slaves, some of which still remain relatively isolated. We studied two such Afro-Brazilian communities (Pacoval and Curiau), in the rural area of Alenquer, Pará, and in the metropolitan region of Macapá, Amapá, respectively. Among 12 blood loci, alleles considered as markers of African ancestry, such as HBB*S, HBB*C, TF*D1, HP*2M, ABO*B, RH*D-, and CA2*2 were found at frequencies that are expected for populations with a predominantly African origin. Estimates of interethnic admixture indicated that the degree of the African component in Curiau (74%) is higher than that of Pacoval (44%); an Amerindian contribution was not detected in Curiau. Estimated values of African ancestry fit well with the degree of isolation and mobility of the communities. Pacoval exhibited a high proportion of immigrants among the parents and grandparents of the individuals studied, whereas persons living in Curiau exhibited a low level of mobility, despite its location in the metropolitan area of Macapá city, suggesting a relatively strong barrier against the interethnic admixture in this population. In addition, analysis of genetic data in a sub-sample consisting of individuals whose parents and grandparents were born in the study site, and that probably represents the populations two generations ago, indicated that gene flow from non-black people is not a recent event in both populations.

Com o objetivo de investigar a origem da mutação <FONT FACE="Symbol">b</font>S na população da região norte do Brasil, foram analisados polimorfismos de DNA no complexo de genes <FONT FACE="Symbol">b</font> da hemoglobina em 30 pacientes com anemia falciforme na população de Belém, a capital do Estado do Pará. Sessenta e sete por cento dos cromossomos <FONT FACE="Symbol">b</font>S analisados apresentaram o haplótipo Bantu, 30% o haplótipo Benin e 3% o haplótipo Senegal. A origem da mutação<FONT FACE="Symbol"> b</font>S na população de Belém, estimada de acordo com a distribuição de haplótipos, não está de acordo com a esperada com base em dados históricos sobre o tráfico de escravos para a região norte, os quais indicam uma reduzida contribuição de escravos da região do Benin. Essas diferenças podem ser atribuídas ao tráfico interno de escravos, bem como ao posterior fluxo de populações imigrantes, particularmente de nordestinos. A distribuição de haplótipos em Belém não difere significativamente da observada em outras regiões brasileiras, muito embora os dados históricos sugiram que a maioria dos escravos procedentes da região do Atlântico-Oeste africano, onde predomina o haplótipo Senegal, foi trazida para o norte do Brasil, enquanto que o nordeste (Bahia, Pernambuco e Maranhão) recebeu o maior contingente de escravos oriundos da região centro-oeste africana, onde o haplótipo Benin é o mais comum. Nós sugerimos que as diferenças regionais quanto à procedência dos escravos africanos também foram modificadas pelo tráfico de escravos estabelecido entre as diferentes regiões brasileiras e posteriormente pelos movimentos migratórios.

We analyzed DNA polymorphisms in the <FONT FACE="Symbol">b</font>-globin gene cluster of 30 sickle cell anemia patients from Belém, the capital city of the State of Pará, in order to investigate the origin of the <FONT FACE="Symbol">b</font>S mutation. Sixty-seven percent of the <FONT FACE="Symbol">b</font>S chromosomes were Bantu type, 30% were Benin type, and 3% were Senegal type. The origin of the <FONT FACE="Symbol">b</font>S mutation in this population, estimated on the basis of <FONT FACE="Symbol">b</font>S-linked haplotypes, contradicts the historical records of direct slave trade from Africa to the northern region of Brazil. Historical records indicate a lower percentage of people from Benin. These discrepancies are probably due to domestic slave trade and later internal migrations, mainly from northeastern to northern regions. Haplotype distribution in Belém did not differ significantly from that observed in other Brazilian regions, although historical records indicate that most slaves from Atlantic West Africa, where the Senegal haplotype is prevalent, were destined for the northern region, whereas the northeast (Bahia, Pernambuco and Maranhão) was heavily supplied with slaves from Central West Africa, where the Benin haplotype predominates.