Mannose-binding lectin 2 (Mbl2) gene polymorphisms are related to protein plasma levels, but not to heart disease and infection by Chlamydia

The presence of the single nucleotide polymorphisms in exon 1 of the mannose-binding lectin 2 (MBL2) gene was evaluated in a sample of 159 patients undergoing coronary artery bypass surgery (71 patients undergoing valve replacement surgery and 300 control subjects) to investigate a possible association between polymorphisms and heart disease with Chlamydia infection. The identification of the alleles B and D was performed using real time polymerase chain reaction (PCR) and of the allele C was accomplished through PCR assays followed by digestion with the restriction enzyme. The comparative analysis of allelic and genotypic frequencies between the three groups did not reveal any significant difference, even when related to previous Chlamydia infection. Variations in the MBL plasma levels were influenced by the presence of polymorphisms, being significantly higher in the group of cardiac patients, but without representing a risk for the disease. The results showed that despite MBL2 gene polymorphisms being associated with the protein plasma levels, the polymorphisms were not enough to predict the development of heart disease, regardless of infection with both species of Chlamydia.

Characterization of polymorphisms in the mannose-binding lectin gene promoter among human immunodeficiency virus 1 infected subjects

The present study investigated the prevalence of mutations in the -550 (H/L) and -221 (X/Y) mannose-binding lectin (MBL) gene promoter regions and their impact on infection by human immunodeficiency virus 1 (HIV-1) in a population of 128 HIV-1 seropositive and 97 seronegative patients. The allele identification was performed through the sequence-specific primer polymerase chain reaction method, using primer sequences specific to each polymorphism. The evolution of the infection was evaluated through CD4+ T-lymphocyte counts and plasma viral load. The allele and haplotype frequencies among HIV-1-infected patients and seronegative healthy control patients did not show significant differences. CD4+ T-lymphocyte counts showed lower levels among seropositive patients carrying haplotypes LY, LX and HX, as compared to those carrying the HY haplotype. Mean plasma viral load was higher among seropositive patients with haplotypes LY, LX and HX than among those carrying the HY haplotype. When promoter and exon 1 mutations were matched, it was possible to identify a significantly higher viral load among HIV-1 infected individuals carrying haplotypes correlated to low serum levels of MBL. The current study shows that haplotypes related to medium and low MBL serum levels might directly influence the evolution of viral progression in patients. Therefore, it is suggested that the identification of haplotypes within the promoter region of the MBL gene among HIV-1 infected persons should be further evaluated as a prognostic tool for AIDS progression.

Polymorphism in the promoter region of the mannose-binding lectin gene among human T-cell lymphotropic virus infected subjects

The present study investigated the frequency of the mutations at positions -550 and -221 of the mannose-binding lectin (MBL) gene in a sample of 75 human T-cell lymphotropic virus (HTLV) infected patients and 96 HTLV seronegative controls, in order to evaluate the occurrence of a possible association between the polymorphism and HTLV infection. A sequence specific primer-polymerase chain reaction was used for discrimination of the polymorphism. The analysis of allele frequencies at position -550 did not show any significant differences between HTLV infected group and controls, but there was a significant difference at position -221. The comparative analysis of haplotypes frequencies were not significant, but the genotype frequencies between the two groups, revealed a higher prevalence of genotype LYLX (25.3 percent), associated with medium and low MBL serum levels among HTLV infected subjects. The odds ratio estimation demonstrated that the presence of genotype LYLX was associated with an increased risk of HTLV infection (p = 0.0096; 1.38 < IC95 percent < 7.7605). There was no association between proviral load and the promoter polymorphism, but when promoter and exon 1 mutations were matched, it was possible to identify a significant higher proviral load among HTLV infected individuals carrying haplotypes correlated to low serum levels of MBL. The present study shows that the polymorphism in the promoter region of the MBL gene may be a genetic marker associated with HTLV infection, and emphasizes the need for further studies to determinate if the present polymorphism have any impact on diseases linked to HTLV infection.

Identification of human T-cell lymphotropic virus infection in a semi-isolated Afro-Brazilian quilombo located in the Marajó Island (Pará, Brazil)

Antibodies to human T-cell lymphotropic virus-1 and 2 (HTLV-1 and 2) were tested in 259 inhabitants (98 males and 161 females) of four villages of the Marajó Island (Pará, Brazil) using enzyme immunoassays (ELISA and Western blot). Types and subtypes of HTLV were determined by nested polymerase chain reaction (PCR) targeting the pX, env and 5 LTR regions. HTLV-1 infection was detected in Santana do Arari (2.06 percent) and Ponta de Pedras (1 percent). HTLV-2 was detected only in Santana do Arari (1.06 percent). Sequencing of the 5 LTR region of HTLV-1 and the phylogenetic analysis identified the virus as a member of the Cosmopolitan Group, subgroup Transcontinental. Santana do Arari is an Afro-Brazilian community and the current results represent the first report of HTLV-1 infection in a mocambo located in the Brazilian Amazon region.

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

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.

Detection of HTLV-IIa 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.

The human lymphotropic viruses type I (HTLV-I) and type II (HTLV-II) are members of a group of mammalian retroviruses with similar biological properties, and blood transfusion is an important route of transmission. HTLV-I is endemic in a number of different geographical areas and is associated with several clinical disorders. HTLV-II is endemic in several Indian groups of the Americas and intravenous drug abusers in North and South America, Europe and Southeast Asia. During the year of 1995, all blood donors tested positive to HTLV-I/II in the State Blood Bank (HEMOPA), were directed to a physician and to the Virus Laboratory at the Universidade Federal do Pará for counselling and laboratory diagnosis confirmation. Thirty-five sera were tested by an enzyme immune assay, and a Western blot that discriminates HTLV-I and HTLV-II infection. Two HTLV-II positive samples were submitted to PCR analysis of pX and env genomic region, and confirmed to be of subtype IIa. This is the first detection in Belém of the presence of HTLV-IIa infection among blood donors. This result emphasizes that HTLV-II is also present in urban areas of the Amazon region of Brazil and highlights the need to include screening tests that are capable to detect antibodies for both types of HTLV.

Detection of carrier status of hemophilia B using DNA markers.

Hemophilia B is an X-linked recessive disorder of the hemostasis involving a defective clotting factor IX. Amplification of the regions containing restriction fragment length polymorphisms (RFLP) can be achieved by the use of polymerase chain reaction (PCR). This paper describes the analysis of 2 RFLPs involving the Dde1 and Taq1 restriction sites within the factor IX gene in a family with hemophilia B. Digestion of the PCR products with Taq1 revealed a 163bp fragment in all the family members. This finding suggests the absence of restriction site for Taq1 enzyme. However, the Dde1 digest results in bands 369bp and 319bp segregated amongst the family members. The pattern of inheritance of the 369bp fragment in this family suggested that both the patient's mother and aunt are not carriers and that the patient's factor IX gene could have undergone a de novo mutation producing a defective factor IX gene responsible for the hemophilia B. This is supported by the fact that no family history of hemophilia B is indicated in the other male members within the family.

Amplification of Bcl I region of the factor VIII gene by PCR.

A study was initiated to amplify by polymerase chain reaction (PCR), a short factor VIII gene fragment containing the Bcl I restriction site from hemophilia patients using published primer sequences. Preliminary findings indicated that the resulting fragment is 142 bp long. This fragment, when digested with Bcl I restriction enzyme produced two fragments, 99 bp and 43 bp in length. Polymorphism in the Bcl I region can be used to detect carrier state in the family members of the hemophiliacs.

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

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 por cento; (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 por cento) than the urban groups (12.5 por cento). Its possible that the host genetic background could influence and modulate the replication of the virus in order to generate HB carrier state.

The increasing importance of vitamin B12 deficiency as a contributing factor to anemia in Malaysia.

A comparative study was done to determine the profile of vitamin B12 and folate status in Malaysians during two different periods. For the period of 1987/88, we analysed a total of 9,162 cases (inpatients) referred for vitamin B12 estimation and 10,290 cases for folate estimation. We found that 2.6% were vitamin B12 deficient and 31.2% were folate deficient. For the period of 1992/93, of the 9,962 cases assayed, 8.2% were found to be vitamin B12 deficient whereas 7.6% of the 10,355 cases referred were folate deficient. Vitamin B12 and folate were assayed either using microbiological or radioassays. These findings indicate that there appears to be a change in the status of both vitamin B12 and folate over the five year interval.

Soroepidemiologia retrospectiva do HIV-1 / Retrospective seroepidemiology of HIV-1

Amostras de soro de grupos populacionais dos Estados do Pará e Goiás, coletados ente 1974 e 1980, foram testadas (ELISA, imunofluorescência e immunoblot) para a presença de anticorpos contra o vírus da imunodeficiência humana tipo-1 (HIV-1). O objetivo principal foi de se mapear epidemiologicamente a ocorrência deste vírus em um período anterior a detecçäo da presente epidemia. Quatro amostras dos índios Xicrin foram positivas pelo teste ELISA, porém näo foram confirmadas pelos demais testes. Os resultados negativos sugerem a ausência de circulaçäo do HIV-1, nos grupos testados, no período pré-1980

Biossegurança no laboratório / Biosafety in the laboratory

Nos últimos dez anos tem sido travada uma luta com a finalidade de prevenir a transmissäo de agentes infecciosos dentro de laboratórios. A grande fonte de dispersäo de patógenos por meio de aerossóis, pode ser eliminada satisfatoriamente com o uso de câmaras de segurança biológica. Regras gerais e específicas de biossegurança devem ser cumpridas por todos os usuários de laboratórios que manuseiam patógenos ou materiais potencialmente contaminantes e, eventualmente, avaliados por um comitê de biossegurança independente. O surgimento da síndrome de imunodeficiência adquirida deve servir como fator de estímulo à adoçäo de normas eficazes de segurança laboratorial

Soroepidemiologia de rotavirus em uma populacao infantil, Goiania, Goias, Brasil. / Seroepidemiology of rotavirus in a children population, Goiania Goias, Brazil

Amostras de soro de 125 criancas, com idades entre 0 e 10 anos, da populacao de Goiania, Goias, Brasil, geraram um indice de prevalencia de anticorpos para rotavirus (ensaio imunoenzimatico) de 82,4%.Aparentemente, o maior risco de infeccao pelo virus se da no grupo de 1 a 3 anos. Nao existe diferenca de infeccao de acordo com o sexo. Informacoes soroepidemiologicas a nivel nacional, sao de grande importancia para o melhor conhecimento do comportamento de virus na populacao em risco, principalmente quando existe a possibilidade de uma futura imuno-profilaxia.O teste imuno-enzimatico em comparacao com a contraimuno-eletro-osmoforese, mostrou-se mais sensivel para a deteccao de anticorpos para rotavirus

A imunohemadsorcao, atraves de receptores Fc, como prova diferencial no isolamento de herpetovirus. / Immunehemadsorption through Fc receptors as a differential routine test in the isolation of herpetovirus

O aparecimento de receptores, para a porcao Fc da imunoglobulina G, na membrana de celulas infectadas por herpetovirus, e aproveitado como teste diferencial, para identificacao de isolamentos destes agentes. A imunohemadsorcao, prova que se realiza na deteccao daqueles receptores, e uma tecnica rapida, economica, simples, sensivel, especifica, reproduzivel, confiavel e segura que pode ser usada com sucesso para esta finalidade

Tratamento das infeccoes pelo virus do herpes simples. / Treatment of infections caused by herpes simplex virus

E apresentada breve revisao de drogas de uso terapeutico e medidas de controle que podem afetar o curso de uma infeccao humana pelo virus do herpes simples em varias formas clinicas que a infeccao pode tomar.Comentarios sao feitos para cada quadro clinico e enfase e dada para a necessidade urgente de serem realizados estudos controlados cientificamente, para evitar o tremendo acumulo de dados nao aproveitaveis/

Prevalencia de anticorpos para rubeola em um segmento da populacao feminina, gestantes ou nao, em Goiania. / Prevalence of rubella antibodies in a part of a female population, pregnant or non-pregnant women, in Goiania

Foram testados 205 soros da populacao feminina (15-35 anos) de Goiania contra o virus da rubeola (tecnica de inibicao da hemaglutinacao), para melhor entender a epidemiologia regional de um dos agentes do complexo ToRCH.O porcentual de individuos suscetiveis (titulo maior ou igual 1:80)foi de 10,2% (21/205).Quanto as gestantes, foi possivel estudar o grupo etario de 20-30 anos, o qual mostrou um total de 15,5% (11/71) de suscetiveis

A racionalidade do correto diagnostico das viroses: importancia e funcao na area de saude humana. / The rationality of the correct diagnosis of virus diseases: importance and function in the area of human health

A famosa e difundida "inexistencia de medicamentos antivirais", a "benignidade" dessas doencas e a "nao utilidade dos resultados do laboratorio de virus para a manutencao do paciente" sao as justificativas mais frequentes para o diagnostico de uma virose nao ser estabelecido. Entretanto, para o paciente, em geral desavisado, a desculpa de um processo viral e a mais comum. O laboratorio de diagnostico de viroses e de importancia fundamental, pois estamos em um periodo de descricao de doencas e atraves dele se torna possivel a instituicao adequada de: a) prognostico e manutencao do individuo; b) formas de tratamento; c) controle e medidas profilaticas. Em Saude Publica, o laboratorio de diagnostico de viroses e um indicativo da prevalencia e incidencia de viroses da regiao, sugerindo medidas de acao adequadas, alem de ser um centro primario de treinamento e formacao de pessoal. Metodos de pesquisa de virus devem ser sustituidos por metodos de diagnostico que tenham a finalidade de fornecer informacao utilizavel, no menor espaco de tempo. O laboratorio de diagnostico de viroses deve ser estimulado para prestar maior apoio a comunidade