Artigos Científicos - ICB

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Soroepidemiologia de rotavírus em uma população infantil, Goinia, Goiás, Brasil
(1984-10) ISHAK, Ricardo; LINHARES, Alexandre da Costa; GABBAY, Yvone Benchimol; ISHAK, Marluísa de Oliveira Guimarães; CARDOSO, Divina das Dôres de Paula
A sample of 125 sera from children aged 0-10 years old from Goiânia, Goiás, Brazil, yielded an 82.4% prevalence rate of antibodies to rotavirus (through an enzyme immunoassay). In this study, the 1-3 year old group shows the highest risk of infection with rotavirus. No sex difference was evident. Regional seroepidemiological data is of the utmost importance in order to identify the behaviour of the virus in the population at risk, specially with the advent of a vaccine for the agent. The enzyme imu- noassay test was compared to counterimmuno-electro-osmophoresis and was shown to be more sensitive for the detection of antibodies.
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Prevalência de anticorpos para chlamydia trachomatis em grupos populacionais do Brasil, Inglaterra e Portugal
(1988-02) ISHAK, Marluísa de Oliveira Guimarães; MUMTAZ, Gilanfan; ISHAK, Ricardo; RIDGWAY, Geoff
The prevalence of group - specific antichlamydial IgG in populations from Brazil, England and Portugal was studied using the whole inclusion - indirect immunofluorescence test, and SA2 (f) as antigen. Those sera with the IgG titre > 1:32, were considered to be positive. Among the Brazilian populations, prevalence of chlamydial antibody was higher in Serra Norte (76,2%, p < 0,01) than in Belém (53,6%) and among Xicrins Indians (51,3%). In patients attending the Departament of Genito Urinary Medicine, University College Hospital and in members of the UCH staff, London, England, the prevalence of antichlamydial IgG was 62% and 53,1%, respectively. Antibody to Chlamydia was detected in 54% and 66% of the English women and in 56 and 68% of the Portuguese women attending Antenatal and Infertility Clinics, respectively. These results show a wide exposure to Chlamydia among all the populations tested, mainly among the low socio-economic group of Serra Norte, Brazil. Evidence of chlamydial infections is of the same order in Brazil, England and Portugal.
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Biossegurança no laboratório
(1989-04) ISHAK, Ricardo; LINHARES, Alexandre da Costa; ISHAK, Marluísa de Oliveira Guimarães
The occurrence of laboratory-acquired infections have elicited in the last ten years an intense interest in methods and procedures for the safe handling of microbiological material. The major laboratory safety problem is aerial transmission, however, protection against airborne hazards is efficiently achieved by the use of microbiological safety cabinets. Biosafety rules should be strictly followed by all members of a laboratory. Evaluation of these procedures should be effectively performed by an independent biosafety committee. The/ upsurge of AIDS should stimulate the adoption of safe working procedures in the laboratory.
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Soroepidemiologia retrospectiva do HIV-1
(1989-04) ISHAK, Ricardo; ISHAK, Marluísa de Oliveira Guimarães; CARDOSO, Divina das Dôres de Paula; TSIQUAYE, K.
Serum samples collected between 1974 and 1980 out of populations from the States of Pará and Goiás, Brazil, were tested for antibodies against HIV-1 through ELISA, immunofluorescence, and immunoblot. The aim was to describe the possibility of the virus presence in this country before the present epidemic. Four samples from an epidemiologically closed community, the Xicrin indians, gave positive reaction in the ELISA test, but were negative in the confirmatory tests. The negative results suggest the absence of HIV-1, in the groups tested, prior to the 1980's.
Acesso aberto (Open Access)
Prevalence of human T cell leukemia virus-I (HTLV-I) antibody among populations living in the Amazon region of Brazil (preliminary report)
(1990-03) NAKAUCHI, C. M.; LINHARES, Alexandre da Costa; MARUYAMA, Koshi; KANZAKI, Luis Isamu Barros; MACEDO, J. E.; AZEVEDO, Vânia Nakauth; CASSEB, Jorge Simão do Rosário
Prevalence of human T cell leukemia virus-I (HTLV-I) antibody among populations living in the Amazon region of Brazil (preliminary report)NakauchiC. M.LinharesA. C.MaruyamaK.KanzakiL. I.MacedoJ. E.AzevedoV. N.CassebJ. S. R. Fundação Serviços de Saúde Pública, Seção de Vírus, Instituto Evandro Chagas Belém Brasil Chiba Cancer Research Institute, Department of Pathology Chiba Japan Universidade Federal do Pará Belém Brasil Instituto Offir Loyola Belém Brasil Faculdade Estadual de Medicina Belém Brasil 0319908512933Forty-tree (31.4%) out of 137 serum samples obtained from two Indian communities living in the Amazon region were found to be positive for HTLV-I antibody, as tested by enzyme-linked immunosorbent assay (Elisa). Eighty-two sera were collected from Mekranoiti Indians, yielding 39% of positivity, whereas 11 (20.0%) or the 55 Tiriyo serum samples had antibody to HTLV-I. In addition, positive results occurred in 10 (23.2%) out of 43 sera obtained from patients living in the Belem area, who were suffering from cancer affecting different organs. Five (16.7%) out of 30 Elisa positive specimens were also shown to be positive by either Western blot analysis (WB) or indirect immunogold electron microscopy (IIG-EM).
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The thermal stability of yellow fever vaccines
(1990-09) ISHAK, Ricardo; HOWARD, Colin R.
The assessment of yellow fever vaccine thermostability both in lyophilized form and after reconstitution were analyzed. Two commercial yellow fever vaccines were assayed for their thermal stability. Vaccines were exposed to test temperatures in the range of 8 (graus) C to 45 (graus) C. Residual infectivity was measured by a plaque assay using Vero cells. The titre values were used in an accelerated degradation test that follows the Arrhenius equation and the minimum immunizing dose was assumed to be 10 (ao cubo) particles forming unit (pfu)/dose. Some of the most relevant results include that (i) regular culture medium show the same degradation pattern of a reconstituted 17D-204 vaccine; (ii) reconstituted YF-17D-204 showed a predictable half life of more than six days if kept at 0 (graus) C; (iii) there are differences in thermostability between different products that are probably due to both presence of stabilizers in the preparation and the modernization in the vaccine production; (iv) it is important to establish a proper correlation between the mouse infectivity test and the plaque assay since the last appears to be more simple, economical, and practical for small laboratories to assess the potency of the vaccine, and (v) the accelerated degradation test appears to be the best procedure to quantify the thermostability of biological products.
Acesso aberto (Open Access)
Prevalence of HTLV-I antibody among two distinct ethnic groups inhabiting the Amazon region of Brazil
(1992-08) NAKAUCHI, C. M.; MARUYAMA, Koshi; KANZAKI, Luis Isamu Barros; LINHARES, Alexandre da Costa; AZEVEDO, Vânia Nakauth; FUKUSHIMA, T.; MIYAUCHI, M.; KOSHIKAWA, N.; TAMAYAMA, C.; MOCHIZUKI, S.; KAWAMURA, K.
HTLV-I seroprevalences of 3.63% (02/55), 12.19% (10/82) and 13.88% (10/72) were demonstrated among Tiryio, Mekranoiti and Xicrin Amazonian Indians, respectively, by the Western blotting enzyme assay (WBEI). By indirect immuno electron microscopy (IIEM), 2 Tiriyo, 9 Mekranoiti and 6 Xicrin Amerindians were reactive. Of 44 serum samples from Japanese immigrants, none reacted by any of the techniques before mentioned. One, 8 and 6 serum samples from Tiryio, Mekranoiti and Xicrin Indians, respectively, were both WBEI and IIEM positive. Our results strongly suggest that HTLV-I and/or an HTLV-I antigenic variant circulate (s) among populations living in the Amazon region of Brazil.
Acesso aberto (Open Access)
Protein phenotypes and productive traits in landrace, large white and duroc swine
(1995) TAGLIARO, Claudia Helena; FRANCO, Maria Helena Lartigau Pereira; MEINCKE, Werner; SILVA, Gilberto
Fourteen protein systems coded by 15 structural loci were typed by horizontal electrophoresis to determine possible associations betweem the protein phenotypes and productive traits in Landrace (N=109), Largo White (N= 116) and Duroe (N=57) pigs, reared in Southern Brazil. Signiticant associations between protein phenotypes and production traits were detected. The most consistent interaction were observed between two protein systems (phosphogluconate dehydrogenase - Pgd and Hemopexin -Hpx) and at least one of the four performance variables considered. In Duroc breed, the Pgd phenotypes were associated with daily weight gain (P < 0.01), feed conversion ratio (P < 0.01) and selection index (P < 0.001), while in Landrace significant associations were observed only with feed convertion ratio (P < 0.05). The Hpx phenotypes were associated with daily weight gain (P < 0.05) and backfat thickness (P < 0.05) in Large White and with this last variable (P < 0.01) and selection index (P < 0.05) in Duroc pigs. Since these results had not been reported previously, turther studies are need to confirm these associations.
Acesso aberto (Open Access)
A possible correlation between the host genetic background in the epidemiology of Hepatitis B virus in the Amazon region of Brazil
(1995-08) SANTOS, Ândrea Kely Campos Ribeiro dos; ISHAK, Marluísa de Oliveira Guimarães; SANTOS, Sidney Emanuel Batista dos; GUERREIRO, João Farias; ISHAK, Ricardo
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.
Acesso aberto (Open Access)
Inquérito soroepidemiológico para os vírus influenza em Belém, Pará, Brasil, 1992-1993
(1997-03) SANTOS, Domingos Ezenildo Matos dos; CARDIAS, Cláudia Alessandra da Silva; MELLO, Wyller Alencar de
A seroepidemiological study was carried out from 1992 to 1993 to estimate the prevalence of antibody to prevailing influenza virus strains circulating among patients attending the IEC Virology Laboratory in Belem, Northern Brazil. A total of 179 (11%) of serum samples were obtained during the post-epidemic period and processed by the hemagglutination inhibition test against the A/Taiwan/1/86 (H1N1), A/Beijing/353/89 (H3N2), and B/Yamagata/16/88 types of influenza virus. The serological results indicate circulation of viruses antigenically related to all three strains during the two-year study period. In 1992, the overall prevalence rates of HI antibodies to H1N1 and H3N2 were 84% and 56%, respectively. Presence of antibodies to both strains was detected in all age groups, suggesting intense viral activity that year. Antibodies to influenza B were detected at lower levels in all patients during this period. Similar prevalence to the H1N1 virus was noted in 1993, indicating that this strain occurred in both years. However, an increase in prevalence rates for the H3N2 virus was seen in 1993, suggesting that this strain (or a related virus) circulated intensively during this year. Influenza B activity also increased in 1993, causing infection mainly among young adults.
Acesso aberto (Open Access)
A comparative study of eleven protein systems in tamarins, genus Saguinus (Platyrrhini, Callitrichinae)
(1997-03) MEIRELES, Carla Maria Marques; SAMPAIO, Maria Iracilda da Cunha; SCHNEIDER, Horacio; FERRARI, Stephen Francis; COIMBRA-FILHO, Adelmar Faria; PISSINATTI, Alcides; SCHNEIDER, Maria Paula Cruz
The genetic variability of six tamarin taxa, genus Saguinus, was analyzed comparatively using protein data from eleven systems coded by 15 loci. S. fuscicollis weddelli and S. midas midas were the most polymorphic taxa, and S. bicolor the least. The results of the phylogenetic analyses (UPGMA and neighbor-joining) and the genetic distances between taxa were generally consistent with their geographic and probable phylogenetic relationships. Analyses of the S. bicolor and S. midas populations suggested that they represent no more than three subspecies of a single species, S. midas, with the bicolor forms belonging to a single subspecies, S. midas bicolor. If supported by additional studies, this would have important implications for the conservation of the bicolor form, which is endangered with extinction. The genetic similarity of S. fuscicollis and S. mystax was also consistent with their geographical and morphological proximity, although more data from a larger number of taxa will be required before the taxonomic relationships within the genus can be defined.
Acesso aberto (Open Access)
Does plasma ANP participate in natriuresis induced by a-MSH?
(1997-04) DINIZ, Domingos Luiz Wanderley Picanço; OLIVEIRA, Gustavo Ribeiro de; FAVARETTO, Ana Lucia Vianna; GUTKOWSKA, J.; MCCANN, S.M.; RODRIGUES, José Antunes
-Melanocyte-stimulating hormone (-MSH; 0.6 and 3 nmol) microinjected into the anteroventral region of the third ventricle (AV3V) induced a significant increase in diuresis without modifying natriuresis or kaliuresis. Intraperitoneal (ip) injection of -MSH (3 and 9.6 nmol) induced a significant increase in urinary sodium, potassium and water excretion. Intraperitoneal (3 and 4.8 nmol) or iv (3 and 9.6 nmol) administration of -MSH did not induce any significant changes in plasma atrial natriuretic peptide (ANP), suggesting that the natriuresis, kaliuresis and diuresis induced by the systemic action of -MSH can be dissociated from the increase in plasma ANP. These preliminary results suggest that -MSH may be involved in a -MSHindependent mechanism of regulation of hydromineral metabolism.
Acesso aberto (Open Access)
Genetic polymorphism and relationships among several swine populations of landrace, large white and duroc breeds
(1997-08) TAGLIARO, Claudia Helena; FRANCO, Maria Helena Lartigau Pereira; WEIMER, Tania Azevedo
The data of three protein polymorphisms were used to investigate the genetic relationships among the Landrace, Large White and Duroc swine breeds reared in Brazil, 12 other populations of these same breeds from various countries and a population of Belgium Landrace. The dendrogram, constructed from matrix of genetic distance coefficients, disclosed three large groups clustered by breed. Among them, the Landrace and the Large White showed in average closer resemblance (D = 0.203) than between them and Duroc (D = 0.241). It the three breeds, the smallest genetic distances were found between Brazilian and Cuban pig populations (Landrace: D = 0.060; Large White: D = 0.052; Duroc: D = 0.065), although there were not reports of pig exchanges between these two countries.
Acesso aberto (Open Access)
Aspectos ultraestruturais do espermatozóide de Natica marochiensish (Gmelin) (Mollusca, Gastropoda) do litoral norte do Brasil
(1997-09) MATOS, Edilson Rodrigues; MATOS, Patrícia Santos; CASAL, Graça Maria Figueiredo; AZEVEDO, Carlos José Correia de
Spermatozoa of Natica marochienssish (Gmelin, 1791) is described by light and electron microscopy. The spermatozoon is of the primitive type with head contains a conical acrosomal complex with an acrosomal vesicle of dense matrix having a basis occupied by the subacrosomal space. The middle piece shows the centriolar complex surrounded by mitochondria and the tail contains the axoneme with a 9+2.
Acesso aberto (Open Access)
Estrutura fina do espermatozóide de Tagelus plebeius (Lightfoot) (Mollusca, Bivalvia) do litoral norte do Brasil
(1997-09) MATOS, Edilson Rodrigues; MATOS, Patrícia Santos; CASAL, Graça Maria Figueiredo; AZEVEDO, Carlos José Correia de
It is described the sperm ultraestructure differentiation during spermiogenesis of Tagelus plebeius (Lightfoot, 1786). The spermatozoon is an uniflagellated cell of the primitive type. The head region contains a rounded or conical nucleus surrounded by acrosome. The middle piece contains four mitochondria which are arranged around the axoneme. The flagellum contains the usual microtubular axoneme.
Acesso aberto (Open Access)
Horizontal projections of area 17 in Cebus monkeys: metric features, and modular and laminar distribution
(1997-12) AMORIM, Ana Karla Jansen de; DINIZ, Cristovam Wanderley Picanço
Metric features and modular and laminar distributions of intrinsic projections of area 17 were studied in Cebus apella. Anterogradely and retrogradely labeled cell appendages were obtained using both saturated pellets and iontophoretic injections of biocytin into the operculum. Laminar and modular distributions of the labeled processes were analyzed using Nissl counterstaining, and/or cytochrome oxidase and/or NADPH-diaphorase histochemistry. We distinguished three labeled cell types: pyramidal, star pyramidal and stellate cells located in supragranular cortical layers (principally in layers IIIa, IIIb α, IIIb ß and IIIc). Three distinct axon terminal morphologies were found, i.e., Ia, Ib and II located in granular and supragranular layers. Both complete and partial segregation of group I axon terminals relative to the limits of the blobs of V1 were found. The results are compatible with recent evidence of incomplete segregation of visual information flow in V1 of Old and New World primates.
Acesso aberto (Open Access)
Cytogenetic study of the genus Saguinus (Callithrichidae, Primates)
(1997-12) DANTAS, Sandra Maria Mendes de Moura; BARROS, Regina Maria de Souza
Eight subspecies from the genus Saguinus (S. fuscicollis fuscicollis, S. fuscicollis weddelli, S. bicolor bicolor, S. bicolor martinsi, S. mystax mystax, S. imperator imperator, S. midas midas, and S. midas niger) were studied. Five of them (S. f. fuscicollis, S. f. weddelli, S. b. martinsi, S. m. mystax and S. i. imperator) had their karyotypes described for the first time. Conventional coloration, banding patterns G, C and NOR, and G/C sequential banding tecniques were used. All samples showed the same diploid number (2n = 46). The patterns of the G, C and NOR bands were very similar with little differences in the quantity and constitutive heterochromatin distribution of the autosomes. Constitutive heterochromatin was observed only in telomeric regions of some chromosomes of S. f. fuscicollis and S. f. weddelli. The X chromosome was the same in all subspecies, but chromosome Y differed in size and morphology. XX/XY chimerism was verified in all subspecies.
Acesso aberto (Open Access)
Ultraestrutura do espermatozóide de Protothaca pectorina (Lamarck) (Mollusca, Bivalvia) do litoral norte do Brasil
(1997-12) MATOS, Edilson Rodrigues; MATOS, Patrícia Santos; CASAL, Graça Maria Figueiredo; AZEVEDO, Carlos José Correia de
The ultrastructure of spermatozoa of the Protothaca pectorina (Lamarck, 1818) is described. The most significam differences were found in the structure and arreangement of the acrosomes, with contains two types of material, one fibrilar, the other electrondense granular. It is concluded that sperm ultrastructure is of the primitive type.
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Malaria vaccine: roadblocks and possible solutions
(1998-03) SOARES, Irene da Silva; RODRIGUES, Mauricio Martins
Malaria remains the most prevalent and devastating parasitic disease worldwide. Vaccination is considered to be an approach that will complement other strategies for prevention and control of the disease in the future. In the last 10 years, intense studies aimed at the development of a malaria vaccine have provided important knowledge of the nature of the host immunological mechanisms of protection and their respective target antigens. It became well established that protective immune responses can be generated against the distinct stages of Plasmodium. However, in general, protective immune responses are directed at stage-specific antigens. The elucidation of the primary structure of these antigens made possible the generation of synthetic and recombinant proteins that are being extensively used in experimental immunizations against the infection. Today, several epitopes of limited polymorphism have been described and protective immunity can be generated by immunization with them. These epitopes are being tested as primary candidates for a subunit vaccine against malaria. Here we critically review the major roadblocks for the development of a malaria vaccine and provide some insight on how these problems are being solved.
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Detection of HTLV-IIa in blood donors in an urban area of the Amazon Region of Brazil (Belém, PA)
(1998-04) ISHAK, Ricardo; ISHAK, Marluísa de Oliveira Guimarães; SANTOS, Domingos Ezenildo Matos dos; VALLINOTO, Antonio Carlos Rosário; SARAIVA, João Carlos Pina; CRESCENTE, Jose Angelo Barletta; HALL, William W.; AZEVEDO, Vânia Nakauth
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.