Comparative cytogenetic analysis in the species Uroderma magnirostrum and U. bilobatum (cytotype 2n = 42) (Phyllostomidae, Stenodermatinae) in the Brazilian Amazon

The genus Uroderma includes two species: U. magnirostrum and U. bilobatum. These species are characterized by their high degree of karyotypic evolution, diverging from most other species of the subfamily Stenodermatinae, which have a lower degree of chromosomic evolution. The present study reports the first banding patterns of U. magnirostrum (G-, C-banding and Ag-NOR) and U. bilobatum (C-banding and Ag-NOR). The chromosomic data in conventional staining of U. magnirostrum (2n = 36, NF = 62) and U. bilobatum (cytotype 2n = 42, NF = 50) are equivalent to that described in the literature. When compared, chromosomal homeologies are found in both karyotypes, as well as differences, confirming that karyotypic evolution in the Uroderma genus is intense. Fission, fusion, inversion or translocation events are required to explain the karyotypic evolution of this genus. The comparison of karyotype, described here, to one of the species of the genus Artibeus (2n = 30/31), suggests that some chromosomic forms are apomorphic and shared between the two species of Uroderma. This confirms the monophyly of the enus, and that U. magnirostrum presents a more primitive karyotype when compared to U. bilobatum

Characterization of 23S rRNA domain V mutations in gastric biopsy patients from the eastern Amazon

Resistance of Helicobacter pylori to clarithromycin is characterised by simple point mutations in the 23S ribosomal RNA (rRNA) gene and is responsible for the majority of cases of failure to eradicate this bacterium. In this paper, we characterised the variability of the 23S rRNA gene in biopsies of patients with gastric pathologies in the eastern Amazon (Northern Region of Brazil) using PCR and sequencing. A total of 49 sequences of H. pylori strains were analysed and of those, 75.6% presented nucleotide substitutions: A2142G (3.3%), T2182C (12.9%), G2224A (6.45%), T2215C (61.3%), A2192G (3.3%), G2204C (6.4%) and T2221C (6.4%). Of the mutations identified, four are known mutations related to cases of resistance and 16.1% are not yet described, revealing a high prevalence of mutations in the H. pylori 23S rRNA gene among the strains circulating in the in the eastern Amazon. The high prevalence in individuals with gastric pathologies in the Northern Region of Brazil demonstrates the need for characterising the profile of these strains to provide correct therapy for patients, considering that mutations in this gene are normally associated with resistance to the primary medication used in controlling H. pylori infection.

Comparative study of human exposure to mercury in riverside communities in the Amazon region

Four populations in the Amazon area were selected for a comparative study of mercury-exposed and non-exposed populations: São Luiz do Tapajós, Barreiras, Panacauera, and Pindobal Grande. The highest mercury levels in human hair samples were found in São Luiz do Tapajós and Barreiras, greatly exceeding the limits established by the World Health Organization. Panacauera showed an intermediate level below 9 µg/g. This was the first comparative and simultaneous evaluation of mercury exposure in the Amazon area. Also, thanks to this type of monitoring, we were able to eliminate the uncertainties about the reference dose. On the basis of these data, we can conclude that the mercury levels detected in exposed populations of the Tapajós River basin may be dangerous not only because they are above the World Health Organization limits, but also because the simultaneous mercury detection in non-exposed populations with similar characteristics provided a valid control and revealed lower mercury levels. Our results support the importance of continuous monitoring in both exposed and non-exposed populations.

Mercury toxicity in the Amazon: contrast sensitivity and color discrimination of subjects exposed to mercury

We measured visual performance in achromatic and chromatic spatial tasks of mercury-exposed subjects and compared the results with norms obtained from healthy individuals of similar age. Data were obtained for a group of 28 mercury-exposed subjects, comprising 20 Amazonian gold miners, 2 inhabitants of Amazonian riverside communities, and 6 laboratory technicians, who asked for medical care. Statistical norms were generated by testing healthy control subjects divided into three age groups. The performance of a substantial proportion of the mercury-exposed subjects was below the norms in all of these tasks. Eleven of 20 subjects (55%) performed below the norms in the achromatic contrast sensitivity task. The mercury-exposed subjects also had lower red-green contrast sensitivity deficits at all tested spatial frequencies (9/11 subjects; 81%). Three gold miners and 1 riverine (4/19 subjects, 21%) performed worse than normal subjects making more mistakes in the color arrangement test. Five of 10 subjects tested (50%), comprising 2 gold miners, 2 technicians, and 1 riverine, performed worse than normal in the color discrimination test, having areas of one or more MacAdam ellipse larger than normal subjects and high color discrimination thresholds at least in one color locus. These data indicate that psychophysical assessment can be used to quantify the degree of visual impairment of mercury-exposed subjects. They also suggest that some spatial tests such as the measurement of red-green chromatic contrast are sufficiently sensitive to detect visual dysfunction caused by mercury toxicity.

Quinine levels in patients with uncomplicated falciparum malaria in the Amazon region of Brazil

We examined the plasmatic concentrations of quinine in patients with uncomplicated falciparum malaria in an endemic area of the Amazon region in Brazil in a prospective clinical trial, in which a standard three-day course of oral quinine plus doxycycline was used. We measured the quinine in the plasma samples on days 0 and 3by high performance liquid chromatography. The mean concentration of quinine was 6.04 ±2.21 µg/mL in male patients and 5.98 ±1.95 µg/mL in female patients. No significant differences in quinine concentration were observed between these two groups. All samples collected before starting treatment were negative for quinine. This information could help in the development of strategies for the rational use of antimalarial drugs in Brazil.

Early larval development in the laboratory of Alpheus estuariensis (Crustacea: Caridea) from the Amazon Region

O presente estudo descreve e ilustra em detalhes os quatro primeiros estágios de Alpheus estuariensis Christoffersen, 1984 a partir de larvas cultivadas em laboratório. Duas fêmeas ovígeras foram coletadas no canal de maré do estuário de Bragança, estado do Pará, nordeste do Brasil. Após a eclosão, as larvas foram colocadas em pequenos recipientes (com 10 larvas em cada). As fêmeas foram depositadas no Museu Paraense Emilio Goeldi (MPEG 0803) e as larvas de cada estágio larval no Museu zoológico da Universidade de São Paulo (MUSP18452). Foram dissecadas 10 larvas e exúvias com finas agulhas sob um microscópio ocular. Comparações morfológicas com outros estudos reportados sobre o desenvolvimento larval de espécies de Alpheus são brevemente discutidas.

Precolumbian land use and settlement pattern in the Santarém region, lower Amazon

Uma das áreas mais promissoras para o estudo das sociedades pré-colombianas complexas na bacia do rio Amazonas é a área do baixo curso dos rios Tapajós, Trombetas e Nhamundá. Há relatos escritos sobre os Konduri e os Tapajós, apresentando informações sobre a sua organização social regional, padrões de comércio, a abundância de alimentos, e o mundo material. Assim, evidências arqueológicas – sítios imensos, solos antrópicos, e belos artefatos – podem ser contrastadas com a informação escrita. Estes ricos depósitos culturais estão desaparecendo a um ritmo alarmante, à medida em que os centros urbanos crescem e se expande a agricultura na região. Apesar desta situação, pouca pesquisa arqueológica tem sido realizada na área, especialmente quando se trata de investigar os antigos padrões de assentamento e redes de trocas. Nos últimos anos, temos realizado pesquisas na bacia do baixo rio Tapajós. O registro arqueológico indica que a cerâmica mostrando forte semelhança estilística forte com a encontrada no grande sítio central está espalhada por pelo menos 90 quilômetros ao sul da presente cidade de Santarém. Este artigo apresenta os resultados de uma pesquisa regional realizada nas proximidades de Santarém, no planalto de Belterra e Alter do Chão, oferecendo uma análise preliminar do sistema de assentamentos na região.

Simulation of soybean growth and yield under northeastern Amazon climatic conditions

O objetivo deste trabalho foi parametrizar, calibrar e validar uma nova versão do modelo de crescimento e de produtividade da soja desenvolvido por Sinclair, em condições naturais de campo no nordeste da Amazônia. Os dados meteorológicos e os valores de crescimento e de área foliar da soja foram obtidos em um experimento agrometeorológico realizado em Paragominas, PA, de 2006 a 2009. As condições climáticas durante o experimento foram muito distintas, com uma ligeira redução na precipitação em 2007, em virtude do fenômeno El Niño. Houve redução no índice de área foliar (IAF) e na produção de biomassa neste ano, a qual foi reproduzida pelo modelo. A simulação do IAF apresentou raiz do erro quadrado médio (REQM) de 0,55 a 0,82 m2 m‑2, de 2006 a 2009. A simulação da produtividade da soja para os dados independentes apresentou um REQM de 198 kg ha‑1, ou seja, uma superestimativa de 3%. O modelo encontra-se calibrado e validado para as condições climáticas da Amazônia e pode contribuir positivamente para a melhoria das simulações dos impactos da mudança de uso da terra na região amazônica. A versão modificada do modelo de Sinclair simula adequadamente a formação de área foliar, a biomassa total e a produtividade da soja, nas condições climáticas do nordeste da Amazônia.

Database of the Amazon aromatic plants and their essential oils

The aromatic flora of the Amazon has been inventoried for 30 years. In this sense, were made over 500 field trips to collect over 2500 plants and to obtain more than 2000 essential oils and aroma concentrates, all of them submitted to GC and GC-MS. This work led to the creation of a database for the aromatic plants of the Amazon, which catalogs general information about 1250 specimens. The database has allowed the publication of the chemical composition of the oils and aromas of more than 350 species, associated with a larger number of chemical types. The essential oils of many species offer optimum conditions for economic exploitation and use in national and international market of fragrances, cosmetics, agricultural and household pesticides.

Plant sources of amazon rosewood oil

The aim of this study is to reevaluate the plant sources of the Amazon rosewood oil which have been named Aniba rosaeodora Ducke and Aniba duckei Kosterm. There is some disagreement on the exact botanical status of these species. Some Lauraceae specialists analyzing available material from both species concluded that there is no basis for regarding them as different. Based on our results we are confirming that the chemical composition of both species is quite different from that previously reported. So we are suggesting to bring back the previous botanical rosewood status as proposed by Adolph Ducke.

A possible correlation between the host genetic background in the epidemiology of Hepatitis B virus in the Amazon region of Brazil

ABSTRACT: The Amazon region of Brazil is an area of great interest because of the large distribution of hepatitis B virus in specific Western areas. Seven urban communities and 24 Indian groups were visited in a total of 4,244 persons. Each individual was interviewed in order to obtain demographic and familial information. Whole blood was collected for serology and genetic determinations. Eleven genetic markers and three HBV markers were tested. Among the most relevant results it was possible to show that (i) there was a large variation of previous exposure to HBV in both urban and non-urban groups ranging from 0 to 59.2%; (ii) there was a different pattern of epidemiological distribution of HBV that was present even among a same linguistic Indian group, with mixed patterns of correlation between HBsAg and anti-HBs and (iii) the prevalence of HBV markers (HBsAg and anti-HBs) were significantly higher (P=0.0001) among the Indian population (18.8%) than the urban groups (12.5%). Its possible that the host genetic background could influence and modulate the replication of the virus in order to generate HB carrier state.

Molecular evidence of mother-to-child transmission of HTLV-IIc in the Kararao Village (Kayapo) in the Amazon Region of Brazil

Amostras de sangue de índios nativos na aldeia Kararao (Kayapó) foram analisadas, usando-se métodos sorológico e molecular, para caracterizar a infecção e analisar a transmissão do HTLV-II. Observou-se reatividade específica em 3/26 indivíduos, dos quais duas amostras eram de uma mãe e de seu filho. A análise pela RFLP de regiões pX e env confirmou a infecção pelo HTLV-II. A seqüência de nucleotídios do segmento 5'LTR e a análise filogenética mostraram alta similaridade (98%) entre as três amostras e o protótipo HTLV-IIa (mot) e confirmaram a ocorrência do subtipo HTLV-IIc. Houve uma alta similaridade genética (99,9%) entre as amostras da mãe e do filho e a única diferença foi uma deleção de dois nucleotídios (TC) na seqüência materna. Estudos epidemiológicos anteriores entre índios nativos do Brasil forneceram prova da transmissão intrafamilial e vertical do HTLV-IIc. O presente estudo fornece evidência molecular da transmissão do HTLV-IIc de mãe para filho, um mecanismo que em grande parte é responsável pela endemicidade do HTLV nessas populações epidemiologicamente fechadas. Embora a verdadeira via de transmissão seja desconhecida, a amamentação materna poderia ser a mais provável.

Detection of HTLV-IIa in blood donors in an urban area of the Amazon Region of Brazil (Belém, PA)

Os vírus linfotrópicos de células T humanas tipo I (HTLV-I) e tipo II (HTLV-II) são membros de um grupo de retrovírus de mamíferos com propriedades biológicas similares que apresentam como uma das principais rotas de transmissão a transfusão sangüínea. O HTLV-I é endêmico em diferentes áreas geográficas e está associado a vários distúrbios clínicos. O HTLV-II é endêmico em vários grupos indígenas das Américas e em usuários de drogas intravenosas na América do Norte e do Sul, Europa e Sudeste da Ásia. Durante o ano de 1995, todos os doadores de sangue positivos para HTLV-I/II no Banco de Sangue do Estado (HEMOPA), foram direcionados a um médico e ao Laboratório de Virologia na Universidade Federal do Pará, para consulta, aconselhamento e confirmação do diagnóstico laboratorial. Trinta e cinco soros foram testados por um ensaio imunoenzimático e confirmados por um Western blot que discrimina as infecções por HTLV-I e HTLV-II. Amostras soropositivas para HTLV-II foram submetidas à reação em cadeia da polimerase (PCR) para as regiões genômicas env e pX e confirmaram ser do subtipo IIa. Esta é a primeira detecção, em Belém, da presença da infecção pelo HTLV-IIa em doadores de sangue. Estes resultados enfatizam que o HTLV-II está presente em áreas urbanas da região Amazônica e a necessidade de incluir testes de triagem capazes de detectar anticorpos para ambos os tipos de HTLV.

Diversity of Chromobacterium violaceum isolates from aquatic environments of state of Pará, Brazilian Amazon

ABSTRACT: The present study intended to characterize the phenotypic and genetic diversity of Brazilian isolates of Chromobacterium violaceum from aquatic environments within the Amazon region. Nineteen isolates showed morphological properties of C. violaceum and the majority grew at 44°C. Low temperatures, in contrast, showed to be inhibitory to their growth, as eleven isolates did not grow at 10ºC and nine did not produce pigmentation, clearly indicating an inhibition of their metabolism. The largest variation among isolates was observed in the citrate test (Simmons), in which 12 isolates were positive, and in the oxidation/fermentation of sucrose, with six positives isolates. Chloramphenicol, gentamicin and sulfonamides efficiently inhibited bacterial growth. Amplified products of the recA gene were digested with HindII or PstI, which produced three or four restriction fragments patterns, respectively. The combined analysis arranged the isolates into six genospecies. The higher diversity observed in Belém (genotypes C, D, E and F) may be a consequence of intense human occupation, pollution of the aquatic environment or due to the higher diversity of the environments sampled in that region. In conclusion, a high level of genetic and phenotypic diversity was observed, and four new genospecies were described.

Molecular characterization of human T-cell lymphotropic virus coinfecting human immunodeficiency virus 1 infected patients in the Amazon region of Brazil

ABSTRACT: The present work evaluated the epidemiology of human immunodeficiency virus 1/human T-cell lymphotropic virus (HIV-1/HTLV) coinfection in patients living in Belém (state of Pará) and Macapá (state of Amapá), two cities located in the Amazon region of Brazil. A total of 169 blood samples were collected. The sera were tested by enzyme-linked immunosorbent assay to determine the presence of antibodies anti-HTLV-1/2. Confirmation of infection and discrimination of HTLV types and subtypes was performed using a nested polymerase chain reaction targeting the pX and 5' LTR regions, followed by restriction fragment length polymorphism and sequencing analysis. The presence of anti-HTLV1/2 was detected in six patients from Belém. The amplification of the pX region followed by RFLP analysis, demonstrated the presence of HTLV-1 and HTLV-2 infections among two and four patients, respectively. Sequencing HTLV-1 5' LTR indicated that the virus is a member of the Cosmopolitan Group, Transcontinental subgroup. HTLV-2 strains isolated revealed a molecular profile of subtype HTLV-2c. These results are a reflex of the epidemiological features of HIV-1/HTLV-1/2 coinfection in the North region of Brazil, which is distinct from other Brazilian regions, as reported by previous studies.