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Belo Horizonte, Brazil

de Arruda M.M.,University of Brasilia | Figueiredo F.B.,Institute Pesquisa Clinica Evandro Chagas | Cardoso F.A.,Fundacao Ezequiel Dias FUNED | Hiamamoto R.M.,University of Sao Paulo | And 5 more authors.
PLoS ONE | Year: 2013

Background: American visceral leishmaniasis is caused by the protozoan Leishmania infantum. Dogs are the main reservoirs in the domestic transmission cycle. The limited accuracy of diagnostic tests for canine leishmaniasis may contribute to the lack of impact of control measures recommended by the Brazilian Ministry of Health. The objective of this study was to estimate the accuracy of two enzyme-linked immunosorbent assays employing L. major or L. infantum antigens and their reliability between three laboratories of different levels of complexity. Methods: A validation study of ELISA techniques using L. major or L. infantum antigens was conducted. Direct visualization of the parasite in hematoxylin/eosin-stained histopathological sections, immunohistochemistry, and isolation of the parasite in culture.were used as gold standard. An animal that was positive in at least one of the tests was defined as infected with L. infantum. Serum samples collected from 1,425 dogs were analyzed. Samples were separated in three aliquots and tested in three different laboratories. Sensitivity, specificity and the area under de ROC curve were calculated and the reliability was evaluated between the participant laboratories. Results: The sensitivity was 91.8% and 89.8% for the L. major and L. infantum assays, respectively. The specificity was 83.75% and 82.7% for the L. major and L. infantum assays, respectively. The area under de ROC curve was 0.920 and 0.898 for L. major and L. infantum, respectively. The mean intraclass correlation coefficients between laboratories ranged from 0.890 to 0.948 when L. major was used as antigen, and from 0.818 to 0.879 when L. infantum was used. Interpretation: ELISA tests using L. major or L. infantum antigens have similar accuracy and reliability. Our results do not support the substitution of the L. major antigen of the ELISA test currently used for the diagnosis of canine visceral leishmaniasis in Brazil. © 2013 de Arruda et al.

Diniz D.M.,Institute Ensino e Pesquisa da Santa Casa | De Souza A.H.,Lutheran University of Brazil | Pereira E.M.R.,Federal University of Minas Gerais | Da Silva J.F.,Institute Ensino e Pesquisa da Santa Casa | And 8 more authors.
Pharmacology Biochemistry and Behavior | Year: 2014

The effects of intrathecal administration of the toxins Phα1β and ω-conotoxin MVIIA were investigated in visceral nociception induced by an intraperitoneal injection of acetic acid and an intracolonic application of capsaicin. The pretreatments for 2 h with the toxins reduced the number of writhes or nociceptive behaviors compared with the control mice. Phα1β administration resulted in an Imax of 84 ± 6 and an ID50 of 12 (5-27), and ω-conotoxin MVIIA resulted in an Imax of 82 ± 9 and an ID50 of 11 (4-35) in the contortions induced by the intraperitoneal injection of acetic acid. The administration of Phα1β resulted in an Imax of 64 ± 4 and an ID50 of 18 (9-38), and ω-conotoxin MVIIA resulted in an Imax of 71 ± 9 and an ID50 of 9 (1-83) in the contortions induced by intracolonic capsaicin administration. Phα1β (100/site) or ω-conotoxin MVIIA (30 pmol/site) pretreatments caused a reduction in CSF glutamate release in mice intraperitoneally injected with acetic acid or treated with intracolonic capsaicin. The toxin pretreatments reduced the ROS levels induced by intraperitoneal acetic acid injection. Phα1β, but not ω-conotoxin MVIIA, reduced significantly the ROS levels induced by intracolonic capsaicin administration.

Galvao M.A.,Federal University of Ouro Preto | da Silva J.C.,Fundacao Ezequiel Dias FUNED | Teixeira M.C.,Federal University of Ouro Preto
Engenharia Sanitaria e Ambiental | Year: 2013

Laboratory studies were performed at the Central Laboratory of Public Health of Minas Gerais in order to validate the process of infectious waste decontamination (subgroup A1) from the public health service and identify possible flaws in the procedure preliminary to its final disposal. We evaluated both the decontamination of disposable waste packed in thermo-resistant plastic bags as well and the decontamination process of reusable waste from the Tuberculosis Laboratory packed in metallic boxes. The results of the first study indicated a significant deficiency in waste treatment, while in the second case efficacy was demonstrated. Preventive and corrective measures were proposed and adopted as a result of this work and are described herein.

Pereira L.S.A.,Federal University of Minas Gerais | Carneiro M.F.,Fundacao Ezequiel Dias FUNED | Botelho B.G.,Federal University of Minas Gerais | Sena M.M.,Federal University of Minas Gerais | Sena M.M.,Instituto Nacional Of Ciencia E Tecnologia Em Bioanalitica
Talanta | Year: 2016

Calibration transfer is commonly used for spectra obtained in different spectrometers or other conditions. This paper proposed the use of calibration transfer between spectra recorded for the same samples in different physical forms. A new method was developed for the direct determination of nevirapine in solid pharmaceutical formulations based on diffuse reflectance near infrared spectroscopy (NIRS) and partial least squares (PLS). This method was developed with 50 powder mixtures and then, successfully extended to the quantification in intact tablets by using calibration transfer with double window piecewise direct standardization (DWPDS). This chemometric strategy provided good results with a small number of tablet transfer samples, only seven, prepared out of the narrow range of active principle ingredients (API) content around the nominal value of the formulation (100%). The method was fully validated in the working range of 83.0-113.9% of nevirapine and the use of DWPDS allowed to significantly decreasing the root mean square error of prediction (RMSEP) from 4.8% (tablets predicted by a model built with only powder samples) to 2.6%. The range of relative errors decreased from -5.1/8.7% to -4.6/3.3%. Considering that the amount of raw materials demanded for preparing tablets is up to ten times higher than for powder mixtures, this type of application is of particular interest in pharmaceutical analysis. In the context of process analytical technology (PAT), the use of the same multivariate model in different steps of the production is very advantageous, saving time and labor. © 2015 Elsevier B.V. All rights reserved.

Salceda E.,Autonomous University of Puebla | Zaharenko A.J.,Butantan Institute | Peigneur S.,Catholic University of Leuven | Lopez O.,Autonomous University of Puebla | And 4 more authors.
Peptides | Year: 2014

Sea anemones produce ion channels peptide toxins of pharmacological and biomedical interest. However, peptides acting on ligand-gated ion channels, including acid-sensing ion channel (ASIC) toxins, remain poorly explored. PhcrTx1 is the first compound characterized from the sea anemone Phymanthus crucifer, and it constitutes a novel ASIC inhibitor. This peptide was purified by gel filtration, ion-exchange and reversed-phase chromatography followed by biological evaluation on ion channels of isolated rat dorsal root ganglia (DRG) neurons using patch clamp techniques. PhcrTx1 partially inhibited ASIC currents (IC50 ∼ 100 nM), and also voltage-gated K+ currents but the effects on the peak and on the steady state currents were lower than 20% in DRG neurons, at concentrations in the micromolar range. No significant effect was observed on Na+ voltage-gated currents in DRG neurons. The N-terminal sequencing yielded 32 amino acid residues, with a molecular mass of 3477 Da by mass spectrometry. No sequence identity to other sea anemone peptides was found. Interestingly, the bioinformatic analysis of Cys-pattern and secondary structure arrangement suggested that this peptide presents an Inhibitor Cystine Knot (ICK) scaffold, which has been found in other venomous organisms such as spider, scorpions and cone snails. Our results show that PhcrTx1 represents the first member of a new structural group of sea anemones toxins acting on ASIC and, with much lower potency, on Kv channels. Moreover, this is the first report of an ICK peptide in cnidarians, suggesting that the occurrence of this motif in venomous animals is more ancient than expected. © 2013 Elsevier Inc.

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