Plasmodium vivax infection among Duffy antigen-negative individuals from the Brazilian Amazon region: an exception?

We present evidence for Plasmodium vivax infection among Duffy blood group-negative inhabitants of Brazil. The P. vivax identification was determined by both genotypic and non-genotypic screening tests. The Duffy blood group was genotyped by PCR/RFLP and phenotyped using a microtyping kit. We detected two homozygous FY*B-33 carriers infected by P vivax, whose circumsporozoite protein genotypes were VK210 and/or P. vivax-like. Additional efforts are necessary in order to clarify the evidence that P. vivax is being transmitted among Duffy blood group-negative patients from the Brazilian Amazon region. (C) 2007 Published by Elsevier Ltd on behalf of Royal Society of Tropical Medicine and Hygiene.

Evaluation of different rhodium modifiers and coatings on the simultaneous determination of As, Bi, Pb, Sb, Se and of Co, Cr, Cu, Fe, Mn in milk by electrothermal atomic absorption spectrometry

Different kinds of modifiers and coatings on the integrated platform of transversely heated graphite atomizer (THGA) have been tested for the simultaneous determination of two group of elements: the first, the more volatile, formed by arsenic, bismuth, lead, antimony and selenium; the second, the less volatile, formed by cobalt, chromium, cupper, iron and manganese in milk by electrothermal atomic absorption spectrometry. Different Rh-modifiers were studied, such as Rh-coated platforms (Rh), carbide plus rhodium coated platforms (W-Rh, Zr-Rh), carbide-coated platforms (W and Zr) with co-injection of RhCl3, solutions and uncoated platforms with injection of solutions of Pd(NO3)(2), Mg(NO3)(2), and RhCl3. Milk samples were diluted 1:10 in 1.0% HNO3 and injected into the tube. The mass of modifier deposited and co-injected in the tube and the use of end capped tubes were also evaluated in order to improve the electrothermal behavior of analytes. Integrated platform pretreated with W plus co-injection RhCl3 for first group and pretreated with W-Rh for second group were elected. For 20 mu L injected samples the analytical curves in the 5.0-20.0 mu g L-1 concentration range have good linear correlation coefficients (r > 0.998). Relative standard deviations (n = 12) are < 6% and the calculated characteristic masses are between 5 pg and 62 pg.

Importância de Yersinia enterocolitica em microbiologia médica

Y. enterocolitica is a human invasive enteropathogen which causes a number of intestinal and extraintestinal clinical symptoms of various degrees of severity, ranging from mild gastroenteritis to mesenteric lymphadenitis, which mimics appendicitis and in rare cases can evolve to septicemia. Infection by Y. enterocolitica can also lead to post-infection immunological sequelae including arthritis, erythema nodosum and glomerulonephritis. Pathogenic Y. enterocolitica strains have traditionally been linked to specific biotypes and serogroups and associated to a variety of phenotypic characteristics related to virulence. Molecular genetics studies have pointed to the importance of the pYV virulence plasmid, which encodes various virulence genes, as well that of specific chromosomal virulence genes, in determining the pathogenesis of this bacterium. Intestinal infections by Y. enterocolitica are mostly self-limiting and usually do not need an antibiotic treatment. The occurrence of this microorganism is not as frequently described in Brazil as it is in other countries, such as Japan, USA and many European countries. This review focuses on the general characteristics, pathogenesis, clinical symptoms, virulence characteristics, treatment and antibiotic susceptibility of Yersinia enterocolitica strains isolated in Brazil and around the world.

Reduced in vitro immune response on titania nanotube arrays compared to titanium surface

Material surfaces that provide biomimetic cues, such as nanoscale architectures, have been shown to alter cell/biomaterial interactions. Recent studies have identified titania nanotube arrays as strong candidates for use in interfaces on implantable devices due to their ability to elicit improved cellular functionality. However, limited information exists regarding the immune response of nanotube arrays. Thus, in this study, we have investigated the short- and long-term immune cell reaction of titania nanotube arrays. Whole blood lysate (containing leukocytes, thrombocytes and trace amounts of erythrocytes), isolated from human blood, were cultured on titania nanotube arrays and biomedical grade titanium (as a control) for 2 hours and 2 and 7 days. In order to determine the in vitro immune response on titania nanotube arrays, immune cell functionality was evaluated by cellular viability, adhesion, proliferation, morphology, cytokine/chemokine expression, with and without lipopolysaccharide (LPS), and nitric oxide release. The results presented in this study indicate a decrease in short- and long-term monocyte, macrophage and neutrophil functionality on titania nanotube arrays as compared to the control substrate. This work shows a reduced stimulation of the immune response on titania nanotube arrays, identifying this specific nanoarchitecture as a potentially optimal interface for implantable biomedical devices. © 2013 The Royal Society of Chemistry.

Influência da música no estado de ânimo e no desempenho em exercícios

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Padronização das plaquetas preparadas in house para atividade do cofator da ristocetina

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Aspectos filogenéticos e sorológicos envolvidos na caracterização das variantes da proteína circunsporozoítica de Palsmodium vivax

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Prevalência dos antígenos eritrocitários caninos em cães domésticos (Canis familiaris) e investigação dos parâmetros hematológicos e da ocorrência de antígenos eritrocitários em lobos-guará (Chrysocyon brachyurus) e cachorros-do-mato (Cerdocyon thos) criados no Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The expression of ABH and Lewis antigens in Brazilian semi-isolated Black communities

The expression of the ABH and Lewis blood groups was determined in blood and saliva samples from two semi-isolated Black communities of Northern Brazil: Cametá and Alcântara. The distributions of ABO blood group phenotypes and the ABH secretor status frequencies showed no significant differences between these populations. In contrast, there was a difference regarding the frequency of the red blood cell Le(a-b-) phenotypes, associated with erythrocyte/saliva discordance, as confirmed by the observation that individuals with Le(a-b-) red cells have the Lewis antigen in their saliva, resulting in a nongenuine Le(a-b-) phenotype, whose frequency was higher in Alcântara.

Expressão dos antígenos ABH e Lewis na gastrite crônica e alterações pré- neoplásica da mucosa gástrica

RACIONAL: A aderência do Helicobacter pylori à mucosa gástrica humana é pré-requisito para sua colonização e o desenvolvimento da gastrite crônica. Os antígenos de grupos sangüíneos, presentes no muco gástrico, são descritos como prováveis receptores da bactéria neste epitélio. A expressão alterada destes antígenos está associada ao desenvolvimento do câncer gástrico. OBJETIVOS: Verificar a ocorrência do Helicobacter pylori e a distribuição da expressão dos antígenos ABH e Lewis correlacionada com as alterações histopatológicas de pacientes com gastrite crônica. PACIENTES E MÉTODOS: Analisaram-se 63 amostras de sangue, saliva e biopsias gástricas de pacientes com gastrite crônica através das técnicas dot-blot-ELISA, imunoperoxidase indireta e colorações do Gram modificado e hematoxilina-eosina. RESULTADOS: Não foram encontradas associações significativas entre a presença da bactéria e os fenótipos de grupos sangüíneos ABH, Lewis e Secretor. Na maioria dos pacientes, a expressão dos antígenos ABH e Lewis, estava restrita principalmente ao epitélio foveolar da mucosa gástrica, concordando com a expressão ao nível salivar. A expressão inapropriada desses antígenos ocorria sempre na infecção pelo Helicobacter pylori e/ou alterações pré-neoplásicas da mucosa gástrica. Em áreas com metaplasia intestinal foi observada a redução da reatividade para os antígenos H e Le^b, e principalmente o aumento de Le^ª. CONCLUSÃO: Alterações no padrão de glicosilação destes antígenos refletem diferentes estágios de diferenciação celular e são marcadores potenciais na avaliação diagnóstica e prognóstica das patologias gástricas.

Imunologia das interações materno-fetais no diabete e na hiperglicemia gestacional leve

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Terapia transfusional em pequenos animais

Blood transfusion is a very important therapeutic and profilatic procedure. However, the most part of the transfusions in animals in Brazil are done with total blood. The transfusion therapy made in an appropriate way, with hemotherapic products, can save lives and warranties a better health to patients. In all transfusion procedures, the cross match test must be done because there are lots of different blood group types, based on erythrocytes antigen. A slow infusion rate and intensive patient monitoration help to prevent transfusion reactions, mainly hemolytic reactions

Influence of nicotine and cotinine impregnation on the first step of periodontal regeneration: clot stabilization

This study analyzes the clot stabilization on root surfaces of teeth impregnated with cotinine and nicotine and the influence of the scaling in the adhesion of blood components, observing the influence of new exposition to nicotine and/or cotinine after scaling. Fifteen human teeth extracted due to periodontal disease of non-smokers patients were selected and manually scaled. Four dentin blocks were obtained from each tooth (n = 60). Samples received blood application or reimpregnation with nicotine and/or cotinine, depending on the groups. Group 1: PBS immersion + root scaling + blood; group 2: nicotine + root scaling + blood; group 3: nicotine + root scaling + nicotine reapplication + blood; group 4: cotinine + root scaling + blood; group 5: cotinine + root scaling + cotinine reapplication+ blood; group 6: nicotine and cotinine + root scaling + nicotine and cotinine + blood. Samples were kept in 2 ml of each substance for 24 hours. Each group received a blood drop and was analyzed by SEM. The higher amount of blood components was present in teeth exposed to cotinine and the groups submitted to scaling and blood application in comparison with groups that received reapplication of toxic substances after scaling. The greater toxic effect on root dentin surface was after the exposure to nicotine and cotinine. Results suggest that periodontal healing may be delayed in smokers due to the direct inhibition of clot stabilization on the root surface when nicotine and cotinine are present concomitantly.

Molecular evolution of a malaria resistance gene (DARC) in primates

Genes involved in host-pathogen interactions are often strongly affected by positive natural selection. The Duffy antigen, coded by the Duffy antigen receptor for chemokines (DARC) gene, serves as a receptor for Plasmodium vivax in humans and for Plasmodium knowlesi in some nonhuman primates. In the majority of sub-Saharan Africans, a nucleic acid variant in GATA-1 of the gene promoter is responsible for the nonexpression of the Duffy antigen on red blood cells and consequently resistance to invasion by P. vivax. The Duffy antigen also acts as a receptor for chemokines and is expressed in red blood cells and many other tissues of the body. Because of this dual role, we sequenced a 3,000-bp region encompassing the entire DARC gene as well as part of its 5' and 3' flanking regions in a phylogenetic sample of primates and used statistical methods to evaluate the nature of selection pressures acting on the gene during its evolution. We analyzed both coding and regulatory regions of the DARC gene. The regulatory analysis showed accelerated rates of substitution at several sites near known motifs. Our tests of positive selection in the coding region using maximum likelihood by branch sites and maximum likelihood by codon sites did not yield statistically significant evidence for the action of positive selection. However, the maximum likelihood test in which the gene was subdivided into different structural regions showed that the known binding region for P. vivax/P. knowlesi is under very different selective pressures than the remainder of the gene. In fact, most of the gene appears to be under strong purifying selection, but this is not evident in the binding region. We suggest that the binding region is under the influence of two opposing selective pressures, positive selection possibly exerted by the parasite and purifying selection exerted by chemokines.

Gen knockdown der Metalloproteasen Meprin alpha 1, alpha 2 und beta im Zebrabärbling Danio rerio

Die Metalloproteasen Meprin α und β übernehmen Schlüsselfunktionen in vielen (patho-) physiologischenrnProzessen. So sind sie beteiligt an der Umstrukturierung der extrazellulären Matrix, an immunologischenrnReaktionen oder an entzündlichen Gewebserkrankungen. Die beiden Enzyme kommenrnhauptsächlich in den Bürstensaummembranen von Niere und Darm sowie in der Haut von Vertebratenrnvor. Für die Erforschung der biologischen Aktivität der Meprine wurde in dieser Arbeit der ModellorganismusrnDanio rerio verwendet, der vor allem durch die Möglichkeit der gentechnischen Manipulationrnprädestiniert ist. Im Fisch konnten drei homologe Enzyme (Meprin α1, α2 und β) nachgewiesenrnwerden. Während mRNA-Analysen eine nahezu ubiquitäre Verteilung der Meprine offenbarten,rnkonnte ich mittels spezifischer Antikörper die Expression auf Proteinebene nachweisen. WährendrnMeprin α1 und β verstärkt im Darmepithel und in der Epidermis lokalisiert sind, konnte Meprinrnα2 ausschließlich in der Lamina propria des Darms identifiziert werden.rnDer Hauptteil der vorliegenden Arbeit zielt auf die spezifische Reduzierung des Expressionslevels derrnMeprine in Embryonen des Zebrabärblings. Dies wurde durch die Mikroinjektion von sogenanntenrnMorpholinos in die Zygote erzielt. Morpholinos sind RNA-Moleküle, die spezifisch an die mRNA desrnZielproteins binden können und die Translation verhindern. Die auftretenden Effekte durch das Fehlenrnder Meprine lassen so Rückschlüsse auf ihre physiologische Funktion zu. Nach der Injektion vonrnMorpholinos gegen Meprin α1 zeigten sich lediglich leichte epidermale Deformationen. Bei Meprin βrnhingegen kam es zu einer massiven Fehlbildung von Organen im Rumpf- und Schwanzbereich. Diesesrnführte zu erheblichen Defekten; die Embryonen starben innerhalb der ersten 24 Stunden nach derrnBefruchtung. Demzufolge müssen Meprin α1 und Meprin β insbesondere an der Gewebsdifferenzierungrnbeteiligt sein. Dies korreliert mit verschiedenen Experimenten, u.a. an knockout Mäusen, ausrndenen hervorgeht, dass die Prozessierung und Aktivierung der Cytokine Interleukin-1β oder Interleukin-rn18 durch Meprin β erfolgen kann.rnDie Injektion von Meprin α2-Morpholinos erbrachte ein weiteres, eindrucksvolles Ergebnis: Das Blutgefäßsystemrnvon injizierten Embryonen war vollständig unterbrochen und es sammelten sich Erythrozytenrnim Bereich der Caudalvene an. Diese Phänotypen gleichen den knockdown-Experimenten mitrndem vascular endothelial growth factor VEGF-A, dem entscheidenden Wachstumsfaktor in der Angiogenesern(Blutgefäßbildung). Eine Inkubation des humanen VEGF-A mit (humanem) rekombinantemrnMeprin α bzw. β führte zu einer differenzierten Prozessierung des Moleküls. Diese Ergebnisse legenrnnahe, dass Meprin α pro-angiogenetisch wirkt, indem es VEGF-A prozessiert und damit die Gefäßbildungrnaktiviert. Aus den Daten dieser Arbeit wird die hohe Signifikanz der Meprine für die Proliferationrnund Differenzierung spezieller Gewebe deutlich, welche somit eine wichtige Grundlage für Studienrnan höheren Vertebraten darstellt.