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The clinical status and tissue parasite burden of the skin and spleen of 40 dogs naturally infected with Leishmania chagasi (syn. Leishmania infantum), together with 5 uninfected control dogs, were assessed. On the basis of the clinical evaluation, infected dogs were classified as asymptomatic (AD) or symptomatic (SD). Infected animals were also grouped according to their parasite load as exhibiting low (LP), medium (MP) and high (HP) parasitism. The results indicated a high parasite load in the skin samples of SD animals in relation to the AD group. The serum immunoglobin isotype profiles of the studied animals revealed increased levels of IgG(1) in the AD and LP dogs, whereas high levels of IgG(2) were correlated with SD and HP dogs. The avidity index (AI) of IgG(total) in the SD group was high in comparison of that of the AD group. Moreover, animals with a larger parasite burden either in the spleen or skin showed higher AI values than animals with lower parasitism. Based on these findings, it is suggested that CVL commences with an asymptomatic clinical form with low parasitism, high production of IgG(1) and low affinity of IgG(total) molecules, and evolves into a symptomatic clinical form with higher parasitism intensity, higher IgG(2) levels, and high affinity of IgG(total)., ((c) 2010 Elsevier B.V. All rights reserved.)

Background: visceral leishmaniasis (VL) is a critical public health problem in over ninety countries. The control measures adopted in Brazil have been insufficient when it comes to preventing the spread of this overlooked disease. In this context, a precise diagnosis of VL in dogs and humans could help to reduce the number of cases of this disease. Distinct studies for the diagnosis of VL have used single recombinant proteins in serological assays; however, the results have been variable, mainly in relation to the sensitivity of the antigens. In this context, the development of multiepitope-based proteins could be relevant to solving such problem. Methods: a chimeric protein (rMELEISH) was constructed based on amino acid sequences from kinesin 39 (k39), alpha-tubulin, and heat-shock proteins HSP70 and HSP 83.1, and tested in enzyme-linked immunosorbent (ELISA) for the detection of L. infantum infection using canine (n = 140) and human (n = 145) sera samples. Results: in the trials, rMELEISH was able to discriminate between VL cases and cross-reactive diseases and healthy samples, with sensitivity and specificity values of 100%, as compared to the use of a soluble Leishmania antigenic extract (SLA). Conclusions: the preliminary data suggest that rMELEISH has the potential to be tested in future studies against a larger serological panel and in field conditions for the diagnosis of canine and human VL. [ABSTRACT FROM AUTHOR]

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Background: Responsible companion animal guardianship (RCAG) comprises a set of concepts involving activities, behavior and care that guardians must provide to ensure the welfare of their animals. When such principles are disregarded, the risk of animals developing zoonotic diseases, such as canine visceral leishmaniasis (CVL), increases. This disease is a public health problem in many urban settings in Brazil because dogs are the main reservoirs of Leishmania and are involved in the transmission of the parasites to humans. Our analytical cross-sectional epidemiological survey aimed to investigate the prevalence of CVL in a city in southeastern Brazil and to establish the association between the disease and a number of predictor variables including dog traits, socioeconomic status of guardians, ecological features of the domicile and RCAG. Results: Our study showed that the global prevalence of CVL in the sample canine population was 6.7% (47/704). All variables related to better dog care were associated with lower chances of infection. Multiple regression analysis revealed that the chances of animals being seropositive for CVL were significantly (p < 0.05) higher when guardians had no formal education or possessed a university degree (vs. those with complete primary or secondary schooling) and when dogs were sheltered outside the house and had free access to the streets. An additional novel finding was that dogs that were acquired as puppies presented half of the chance of developing the disease in comparison with those acquired at the adult stage. Geographically weighted logistic regression coefficients showed that the strengths of the predictor/CVL associations varied depending on the studied geographical space. Both models demonstrated that the associations were always in the same directions. Conclusions: Our findings indicate that regardless of age and mode of acquisition, adult dogs should be submitted to clinical evaluation and tests for CVL. RCAG can exert positive effects on the control of CVL. [ABSTRACT FROM AUTHOR]

Leishmaniasis is responsible for approximately 65,000 annual deaths. Despite the mortality data, drugs available for the treatment of patients are insufficient and have moderate therapeutic efficacy in addition to serious adverse effects, which makes the development of new drugs urgent. To achieve this goal, the integration of kinetic and DSF assays against parasitic validated targets, along with phenotypic assays, can help the identification and optimization of bioactive compounds. Pteridine reductase 1 (PTR1), a validated target in Leishmania sp., is responsible for the reduction of folate and biopterin to tetrahydrofolate and tetrahydrobiopterin, respectively, both of which are essential for cell growth. In addition to the in vitro evaluation of 16 thiazolidine-2,4-dione derivatives against Leishmania major PTR1 (LmPTR1), using the differential scanning fluorimetry (ThermoFluor®), phenotypic assays were employed to evaluate the compound effect over Leishmania braziliensis (MHOM/BR/75/M2903) and Leishmania infantum (MHOM/BR/74/PP75) promastigotes viability. The ThermoFluor® results show that thiazolidine-2,4-dione derivatives have micromolar affinity to the target and equivalent activity on Leishmania cells. 2b is the most potent compound against L. infantum (EC50 = 23.45 ± 4.54 μM), whereas 2a is the most potent against L. braziliensis (EC50 = 44.16 ± 5.77 μM). This result suggests that lipophilic substituents on either—meta and/or—para positions of the benzylidene ring increase the potency against L. infantum. On the other hand, compound 2c (CE50 = 49.22 ± 7.71 μM) presented the highest selectivity index. [ABSTRACT FROM AUTHOR]

Background The physical characteristics of the environment influence the composition, distribution and behavior of the vectors and mammalian hosts involved in the transmission of visceral leishmaniasis (VL), thereby affecting the epidemiology of the disease. In Brazil, urbanization of human VL is a recent phenomenon and represents an issue of particular concern to local health authorities. The present study aimed to establish the degree of spatial dependency between canine and human VL in the municipality of Divinópolis, Minas Gerais, Brazil, and to identify priority risk areas in which stricter control measures should be implemented. Methods The selected canine population comprised 3,652 dogs distributed within 11 strata and 1,247 urban blocks. Serum samples were collected between March 2013 and February 2014. Serodiagnosis of dogs was performed using the enzyme-linked immunosorbent assay and the indirect fluorescent-antibody test. The blocks sampled for canine VL and the addresses of the 16 confirmed cases of human VL notified in Divinópolis during the period 2007-2013 were georeferenced. Spatial analysis of the data was performed using Kernel density estimation, Ripley's bivariate K-function and directional distribution methods. Results The overall prevalence of seropositive animals was 4.63% (range 3.95 - 5.31) (n =169) and varied in different strata between 0.9 (range 0.0 - 1.91) and 8.73% (range 5.65 - 11.81). A positive spatial dependency was detected between human and canine VL in which the occurrence of human cases of the disease tended to concentrate in locations that were close to areas with a higher incidence of canine VL. The priority risk area could be clearly distinguished from Kernel density estimation and standard deviational ellipse plots in which the human VL ellipse was totally enclosed within the canine VL ellipse. Conclusions The results presented herein will enable the Municipal Health Office of Divinópolis to devise a more effective management plan for human VL in which specific strategies would be applied to areas presenting different levels of risk. This spatial evaluation of leishmaniasis model could be applied in other urban areas of Brazil. [ABSTRACT FROM AUTHOR]

Introduction: Leishmaniasis is a set of tropical diseases widely distributed throughout the world. Publications concerning different aspects of leishmaniasis have shown an increasing trend in recent years, especially in Brazil, where this disease has been under continuous expansion. The present study analyzes the data and assess trends in publications on leishmaniasis in Brazil and worldwide. Methodology: The bibliometric analysis was performed on the Scopus database, addressing data on scientific publications about leishmaniasis in the first nineteen years of the 21st century. The tendency of the annual number of publications was analyzed by mean of linear regression equations. Results: The literature search identified 19.317 publications. Brazil was the country with the largest number of studies (24.88%). The annual growth rate for Brazilian publications was 4.66%, whereas worldwide publications grew 2.96%. The leading ten international authors contributed to 8.71% of the publications, whereas the ten principal Brazilian authors contributed to 4.31%. The largest collaboration network between authors was between Brazil and the United States. Oswaldo Cruz Foundation occupied the premier position in both worldwide and Brazilian ranking in number of publications. The international journal with the largest number of publications and SCImago Journal Rank indicator was PLOS Neglected Tropical Diseases. The Journal of Immunology had the highest H-index. Most of the research covered topics related to immunology and molecular biology. Conclusions: The data show relevant characteristics of the scientific production on leishmaniasis and demonstrate the fundamental role played by Brazil in the production of knowledge in this area of study. [ABSTRACT FROM AUTHOR]

• The coordination compounds IbuNi, IbuMn and IbuPd were coordinated through the oxygen atom of the deprotonated carboxylate. • IbuNi presented the highest index of selectivity. • IbuNi and IbuMn were able to reduce the infectivity. • IbuPd showed to be toxic. Leishmaniases are neglected diseases that represent a significant public health concern in several countries. In this study, nickel (II), manganese (II), and palladium (II) coordination compounds with ibuprofen were synthesized, and their potential leishmanicidal activity was evaluated. The compounds were characterized by molar conductimetry, electronics spectroscopy, infrared vibrational spectroscopy, 13C NMR, and elemental analysis, and the data were compared with literature. Comparison of the leishmanicidal activity of these compounds against promastigotes of Leishmania amazonensis and the cytotoxicity against lung fibroblast cells indicated that the IbuNi (nickel ibuprofen complex) compound was promising because it had the highest selectivity index (3.28) compared to the other compounds. In vitro tests on infected macrophages were performed and showed a decrease in infectivity of 31.21% at the concentration of 184.75 μM for the above compound and indicated that IbuPd (palladium ibuprofen complex) was toxic. [ABSTRACT FROM AUTHOR]