A Leishmania-specific hypothetical protein expressed in both promastigote and amastigote stages of Leishmania infantum employed for the serodiagnosis of, and as a vaccine candidate against, visceral leishmaniasis

Background: LiHyV is an antigenic hypothetical protein present in both promastigote and amastigote stages of Leishmania infantum, which was recently identified by an immunoproteomic approach. A recombinant version of this protein (rLiHyV) was evaluated as a diagnostic marker for canine VL (CVL). In addition, the prophylactic efficacy of the rLiHyV protein, and two of its CD8+ T cell epitopes, has been analyzed in a murine model of visceral leishmaniasis (VL). Methods: Initially, the rLiHyV protein was evaluated by an ELISA technique for the serodiagnosis of CVL. Secondly, vaccines composed of the recombinant protein and both chemically synthesized peptides, combined with saponin as an adjuvant; were administered subcutaneously into BALB/c mice. The cellular and humoral responses generated by vaccination were evaluated. In addition, the parasite burden and immune response were studied 10 weeks after L. infantum infection. Results: The rLiHyV protein was recognized by antibodies of VL dogs. No cross-reactivity was obtained with sera from dogs vaccinated with a Brazilian commercial vaccine, with sera from animals infected with Trypanosoma cruzi, Babesia canis and Ehrlichia canis, or those from non-infected animals living in an endemic area for leishmaniasis. After challenge with L. infantum, spleen cells of BALB/c mice vaccinated with rLiHyV/saponin stimulated with parasite antigens showed a higher production of IFN-γ, IL-12 and GM-CSF, than the same cells obtained from mice vaccinated with the individual peptides, or mice from control (inoculated with saline or saponin) groups. This Th1-type cellular response observed in rLiHyV/saponin vaccinated mice was accompanied by the induction of parasite-specific IgG2a isotype antibodies. Animals immunized with rLiHyV/saponin showed significant reductions in the parasite burden in the liver, spleen, bone marrow and in the lymph nodes draining the paws relative to control mice. Conclusions: The present study showed for the first time that the L. infantum LiHyV protein could be considered as a vaccine candidate against L. infantum infection, as well as a diagnostic marker for CVLThis work was supported by grants from Instituto Nacional de Ciência e Tecnologia em Nanobiofarmacêutica (INCT-Nanobiofar), FAPEMIG (CBB-APQ-00819-12), and CNPq (APQ-472090/2011-9, RHAE-456287/2012-4, APQ-482976/2012-8, and APQ-488237/2013-0). MACF is a grant recipient of FAPEMIG/CAPES. EAFC and APF are grant recipient of CNP

Proteins selected in Leishmania (Viannia) braziliensis by an immunoproteomic approach with potential serodiagnosis applications for tegumentary leishmaniasis

The serodiagnosis of human tegumentary leishmaniasis (TL) presents some problems, such as the low level of antileishmanial antibodies found in most of the patients, as well as the cross-reactivity in subjects infected by other trypanosomatids. In the present study, an immunoproteomic approach was performed aimed at identification of antigens in total extracts of stationaryphase promastigote and amastigote-like forms of Leishmania (Viannia) braziliensis using sera from TL patients. With the purpose of reducing the cross-reactivity of the identified proteins, spots recognized by sera from TL patients, as well as those recognized by antibodies present in sera from noninfected patients living in areas where TL is endemic and sera from Chagas disease patients, were discarded. Two Leishmania hypothetical proteins and 18 proteins with known functions were identified as antigenic. The study was extended with some of them to validate the results of the immunoscreening. The coding regions of five of the characterized antigens (enolase, tryparedoxin peroxidase, eukaryotic initiation factor 5a, β-tubulin, and one of the hypothetical proteins) were cloned in a prokaryotic expression vector, and the corresponding recombinant proteins were purified and evaluated for the serodiagnosis of TL. The antigens presented sensitivity and specificity values ranging from 95.4 to 100% and 82.5 to 100%, respectively. As a comparative antigen, a preparation of Leishmania extract showed sensitivity and specificity values of 65.1 and 57.5%, respectively. The present study has enabled the identification of proteins able to be employed for the serodiagnosis of TLThis work was supported by grants from Instituto Nacional de Ciência e Tecnologia em Nano-biofarmacêutica (INCT-Nanobiofar), FAPEMIG (CBB-APQ-00496-11 and CBB-APQ-00819-12), and CNPq (APQ- 472090/2011-9, APQ-482976/2012-8, and APQ-488237/2013-0). In addition, this study was partially funded in Madrid by a Spanish grant from Ministerio de Economía y Competitividad-FEDER (FISPI14/00366 from the Instituto de Salud Carlos III). M.A.C.F. is a grant recipient of FAPEMIG/CAPES. E.A.F.C., A.P.F., and M.O.C.R. are recipients of grants from CNP

Sensitive and specific serodiagnosis of Leishmania infantum infection in dogs by using peptides selected from hypothetical proteins identified by an immunoproteomic approach

In Brazil, the percentage of infected dogs living in areas where canine visceral leishmaniasis (CVL) is endemic ranges from 10 to 62%; however, the prevalence of infection in dogs is probably higher than figures reported from serological studies. In addition, problems with the occurrence of false-positive or false-negative results in the serodiagnosis of CVL have been reported. The present work analyzed the potential of synthetic peptides mapped from hypothetical proteins for improvement of the serodiagnosis of Leishmania infantum infection in dogs. From 26 identified leishmanial proteins, eight were selected, considering that no homologies between these proteins and others from trypanosomatide sequence databases were encountered. The sequences of these proteins were mapped to identify linear B-cell epitopes, and 17 peptides were synthesized and tested in enzyme-linked immunosorbent assays (ELISAs) for the serodiagnosis of L. infantum infection in dogs. Of these, three exhibited sensitivity and specificity values higher than 75% and 90%, respectively, to differentiate L. infantum-infected animals from Trypanosoma cruziinfected animals and healthy animals. Soluble Leishmania antigen (SLA) showed poor sensitivity (4%) and specificity (36%) to differentiate L. infantum-infected dogs from healthy and T. cruzi-infected dogs. Lastly, the three selected peptides were combined in different mixtures and higher sensitivity and specificity values were obtained, even when sera from T. cruzi-infected dogs were used. The study’s findings suggest that these three peptides can constitute a potential tool for more sensitive and specific serodiagnosis of L. infantum infection in dogsThis work was supported by grants from the Pró-Reitoria de Pesquisa from UFMG (Edital 07/2012), Instituto Nacional de Ciência e Tecnologia em Nano-biofarmacêutica (INCT-NANOBIOFAR, Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) (CBB-APQ-02364-08, CBB-APQ-00356-10, CBB-APQ-00496-11, and CBB-APQ-00819-12), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (APQ-472090/2011-9), and the Instituto Nacional de Ciência e Tecnologia em Vacinas (INCT-V). E.A.F.C. and A.P.F. are CNPq grant recipients. M.A.C.-F. is a FAPEMIG/CAPES grant recipient. This study was supported in Spain, in part, by grants from the Ministerio de Ciencia e Innovación (FIS/PI1100095)

Blood tests in microcytic and hypochromic anemias: differential aspects

O diagnóstico diferencial das anemias microcíticas é clinicamente importante. Na tentativa de tornar esse diagnóstico menos oneroso e mais eficiente, o uso de parâmetros dos contadores automáticos tem sido sugerido. O objetivo deste estudo foi avaliar a eficiência diagnóstica de alguns parâmetros do hemograma na diferenciação das anemias microcíticas. Foram comparados os parâmetros hematológicos de 395 pacientes portadores de anemia ferropriva, anemia de doença crônica ou talassemia menor. O número de hemácias apresentou os maiores valores combinados de sensibilidade e especificidade na diferenciação dessas anemias. Em conclusão, a contagem de hemácias pode ser útil no diagnóstico diferencial de anemias microcíticas

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Avaliação da exposição ocupacional ao benzeno em trabalhadores frentistas e analistas de combustíveis utilizando o Teste Cometa como biomarcador de genotoxicidade

Resumo Introdução: frentistas e analistas de combustíveis estão expostos a vários compostos orgânicos voláteis presentes na gasolina, incluindo benzeno, que se destaca por sua importância toxicológica. Objetivo: avaliar a exposição ocupacional ao benzeno na gasolina, utilizando o Teste Cometa como biomarcador de genotoxicidade em comparação ao ácido trans,trans-mucônico urinário (AttM) como biomarcador de exposição ao benzeno. Métodos: estudo de corte transversal com análises de biomarcadores de exposição e de genotoxicidade em grupo de expostos ocupacionalmente ao benzeno através da gasolina e grupo controle. Resultados: o Teste Cometa mostrou uma média (desvio padrão) de índice de dano, expresso em unidades arbitrárias, no grupo exposto de 28,4 (10,1) significativamente mais elevado do que no grupo não-exposto, 18,4 (10,1). O AttM urinário, em mg/g de creatinina, foi significativamente maior no grupo exposto, 1,13 (0,45), em relação ao grupo não exposto, 0,44 (0,33). Os dois biomarcadores apresentaram boa correlação linear (r=0,81; p<0,05), indicando uma forte associação entre o biomarcador de exposição e o biomarcador de efeito. Conclusão: os resultados sugerem que uma maior exposição ocupacional ao benzeno está associada a um risco aumentado de dano genotóxico entre indivíduos expostos à gasolina

Alterações do sistema hemostático nos pacientes com diabetes melito tipo 2 Hemostatic changes in patients with type 2 diabetes mellitus

O diabetes tem adquirido um caráter de epidemia devido ao grande aumento do número de indivíduos acometidos nas últimas décadas. A mortalidade relacionada ao diabetes está associada a eventos trombóticos, principalmente cardiovasculares. De uma maneira geral, pacientes com diabetes apresentam um quadro de hipercoagulabilidade e hipofibrinólise; entretanto, ainda não foram esclarecidos os mecanismos que deflagram as alterações hemostáticas nos indivíduos diabéticos. O objetivo do presente artigo foi abordar as alterações mais frequentes do sistema hemostático descritas na literatura nos indivíduos diabéticos. Os indivíduos diabéticos apresentam alterações endoteliais, plaquetárias, nos fatores de coagulação, nos anticoagulantes naturais e no sistema fibrinolítico, sendo que essas alterações são causadas direta ou indiretamente pela hiperglicemia. Dessa forma, analitos como fator de Von Willebrand, fator VIII, fibrinogênio e D-dímero são marcadores que apresentam interpretações diferenciadas no contexto do paciente diabético. As evidências laboratoriais das alterações hemostáticas nos indivíduos diabéticos suportam a observação clínica de que o diabetes é um estado de hipercoagulabilidade e hipofibrinólise. Ainda não estão bem estabelecidas as estratégias de intervenção clínica e/ou medicamentosa frente aos resultados alterados do sistema hemostático.<br>Diabetes has acquired an epidemic character due to the large increase in the number of individuals affected over recent decades. Diabetes-related mortality is associated with thrombotic events, especially cardiovascular. In general, patients with diabetes present symptoms of hypercoagulability and hypofibrinolysis. However, the mechanisms that trigger hemostatic abnormalities in diabetic patients are not clear. The aim of this paper was to address the most frequent changes of the hemostatic system in diabetic patients described in the literature. Diabetics have abnormalities of the endothelium, platelets, clotting factors, natural anticoagulants and the fibrinolytic system; all these changes are directly and/or indirectly caused by hyperglycemia. Thus, analytes such as von Willebrand factor, factor VIII, fibrinogen and D-dimer are markers that should be interpreted differently in diabetic patients. Laboratory evidence of hemostatic abnormalities in diabetic patients supports clinical observations that diabetes is a state of hypercoagulability and hypofibrinolysis. Strategies for clinical intervention and medications are not well established considering the results of the hemostatic markers

Comet assay as a biomarker of genotoxicity to assess occupational exposure to benzene in gas-station attendants and fuel analysts

<p></p><p>Abstract Introduction: gas-station attendants and fuel analysts are exposed to various volatile organic compounds found in gasoline, including benzene, which stands out because of its toxicological significance. Objective: to assess occupational exposure to benzene using the comet assay as a biomarker of genotoxicity in comparison to the urinary trans, trans muconic acid (ttMA) as benzene exposure biomarker. Methods: cross-sectional study using biomarkers of exposure and genotoxicity analyses in a group of workers occupationally exposed to benzene from gasoline compared with a control group. Results: the comet assay results showed that the mean (standard deviation) damage index, in arbitrary units, in the exposed group, 28.4 (10.1), was significantly higher than in the non-exposed group, 18.4 (10.1). The mean value of urinary ttMA was significantly higher in the exposed group, 1.13 (0.45), compared to the non-exposed group, 0.44 (0.33). Both biomarkers showed a linear correlation r = 0.81 (p<0.05) indicating a strong association between the exposure biomarker and the biomarker effect. Conclusion: the results suggest that a greater occupational exposure to benzene is associated to an increased risk of genotoxic damage among individuals exposed to gasoline.</p><p></p