2,049 research outputs found

    Novel spectrophotometric method for the determination of azithromycin in pharmaceutical formulations based on its charge transfer reaction with quinalizarin

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    This paper proposes a new method for simple and fast spectrophotometric determination of azithromycin in pharmaceutical formulations. The method is based on the charge transfer reaction between the azithromycin and quinalizarin in methanol medium. In order to achieve maximum sensitivity the effect of some chemical variables such as the type of solvent, reagent concentration and reaction time were evaluated. The reaction was characterized in terms of stability of the product formed and its stoichiometry, and the apparent molar absorptivity and association constant were derived. Best conditions for the analytical determination of azithromycin were observed in methanol medium with a quinalizarin concentration of 50 mg L-1. At these conditions, the radical anion (absorbing specie) was formed in the medium immediately after mixing of the reagents and showed maximum absorption at 564 nm. The method presented a limit of detection of 0.35 mg L-1 and a limit of quantification of 1.2 mg L-1. It was successfully applied in the determination of azithromycin in three commercial pharmaceutical formulations of azithromycin and no matrix interferences were observed

    Influencia de la dinámica de estuarios sobre la variabilidad espacial de macrobentos a lo largo de la plataforma continental del sudeste de Brasil

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    Along the southeast continental shelf of Brazil, the Paraíba do Sul River (PSR) plays a fundamental role in sediment and nutrient transport. This study focuses on the contribution of the PSR and its effect on the benthic macrofauna. Physical and chemical analyses of the sediment were conducted, and the macrofauna were identified and counted. Multivariate analyses were used to compare the distribution patterns of the benthic assemblages related to the depth gradient over two sampling periods. The principal component analysis showed that shallow waters assemblages are mostly influenced by the environmental descriptors temperature, salinity and chlorophyll a, whereas pheophytin, degree of sediment sorting, total carbonate and organic carbon were correlated with benthic assemblages at greater depths. The high organic enrichment reflected an increase in surface and sub-surface deposit feeders such as the polychaetes Spiophanes sp. and Prionospio cristata and the crustacean Phtisica marinain the deeper stations, with a corresponding decrease in other trophic groups. This study provides evidence of differences in organic matter sources, from primary production in shallow waters to detritus in deep waters. These sources provide different niches for the corresponding macrofaunal assemblages along the continental shelf adjacent to the PSR, with species richness and abundance of benthic populations related to the river output.A lo largo de la plataforma continental del sudeste de Brasil, el río Paraíba do Sul (RPS) juega un papel fundamental en el transporte de sedimento y nutrientes. Este estudio se enfoca en la contribución del RPS y sus efectos sobre la macrofauna bentónica. Se condujeron análisis físicos y químicos del sedimento, y la macrofauna fue identificada y contada. Se realizaron análisis multivariados para comparar los patrones de distribución de los ensamblajes bentónicos relacionados al gradiente de profundidad en dos periodos de muestreo. El análisis de componentes principales (ACP) mostró que los ensamblajes de aguas poco profundas son influenciados principalmente por los descriptores ambientales de temperatura, salinidad, y clorofila a, mientras que la feofitina, grado de clasificación de sedimentos, carbonato total y el carbón orgánico estaban correlacionados a los ensamblajes bentónicos a mayores profundidades. El alto enriquecimiento orgánico se refleja en un incremento de detritívoros superficiales y sub-superficiales como los poliquetos Spiophanes sp. y Prionospio cristata y el crustáceo Phtisica marinaen las estaciones más profundas, con el decrecimiento correspondiente en otros grupos tróficos. Este estudio provee evidencia de diferencias entre fuentes de materia orgánica, desde la producción primaria en aguas poco profundas hasta detrito en aguas profundas, que proveen distintos nichos a los ensamblajes macrofaunales correspondientes a lo largo de la plataforma continental adyacente al RPS, con la riqueza de especies y abundancia de las poblaciones bentónicas relativas al flujo del rio

    USE OF COMBINATION OF FLUORESCENT PROBES TO IDENTIFY SPERM SUBPOPULATIONS FOR QUALITY ASSESSMENT OF FRESH AND CRYOPRESERVED CANINE SEMEN. PRELIMINARY RESULTS

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    The use of fluorescent markers in the evaluation of sperm morphophysiology allows a better accuracy, compared to the subjective nature of some routine tests in semen qualification. In this study was used the combination of fluorescence probes: propionate iodide, Hoechst 33342 and FITC-PSA in fresh and thawed dog semen, to the identification of the following morphological subpopulations: II (intact plasma and acrosomal membranes), IL (intact plasma membrane and lesioned acrosomal membrane), LI (lesioned plasma membrane and intact acrosomal membrane) and LL (both membranes lesioned). When comparing the results obtained with the results of the tests used conventionally in semen evaluation (sperm motility and vigor, hypoosmotic test and morphological alterations), little correlation was observed. The II population declined from fresh semen to thawed, while LL population increased (p <0.05). The IL population was composed of extremely small numbers of cells but increased (p <0.05) from fresh semen to thawed semen. In the thawed semen the major defects had a positive correlation with the LL population (p <0.01). For the thawed semen, the results of the hypoosmotic test (number of cells that reacted to the medium) correlated positively with population II (p <0.025), that is, different from that observed in fresh semen. Although all tests were able to detect decrease in sperm quality post-thawing (p <0.05). The use of this fluorescent probe association allowed qualification and more accurately quantification of plasma membrane and acrosomal insults mediated by cryopreservation. El uso de marcadores fluorescentes en la evaluación de la morfofisiología espermática permite una mayor precisión, comparada con la naturaleza subjetiva de algunas pruebas de rutina en la valoración del semen. En este estudio se usó la combinación de pruebas fluorescentes: yoduro de propidio; Hoechst 33342 y FITC-PSA en semen fresco y descongelado de perro, para la identificación de las siguientes subpoblaciones morfológicas: II (membranas plasmática y acrosomal intactas), IL (membrana plasmática intacta y membrana acrosomal dañada), LI (membrana plasmática dañada y membrana acrosomal intacta) y LL (ambas membranas dañadas). Cuando se comparan los resultados obtenidos con los resultados de las pruebas usadas convencionalmente en la evaluación seminal (motilidad y vigor espermáticos, prueba hipoosmótica y alteraciones morfológicas), se observó poca correlación. La población II disminuyó desde el semen fresco al descongelado, mientras que la población LL se incrementó (p<0.05). la población IL estuvo compuesta por un número extremadamente pequeño de células, pero incremento (p<0.05) desde el semen fresco al descongelado. En el semen descongelado los defectos mayores tuvieron una correlación positiva con la población LL (p<0.01). En el semen descongelado, los resultados de la prueba hipoosmótica (número de células que reaccionan al medio) se correlacionaron positivamente con la población II (p<0.05). El uso de esta asociación de pruebas fluorescentes permitió la valoración y la cuantificación más precisa de los daños a la membrana plasmática y acrosomal mediados por la criopreservación.

    That anthropology was not for us

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    Special interview - Cadernos de Campo - 25 year

    The Genome of Anopheles darlingi, the main neotropical Malaria vector

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    Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vector–human and vector–parasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible a

    Manual Hippocampal Subfield Segmentation Using High-Field MRI: Impact of Different Subfields in Hippocampal Volume Loss of Temporal Lobe Epilepsy Patients

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    In patients with temporal lobe epilepsy (TLE), presurgical magnetic resonance imaging (MRI) often reveals hippocampal atrophy, while neuropathological assessment indicates the different types of hippocampal sclerosis (HS). Different HS types are not discriminated in MRI so far. We aimed to define the volume of each hippocampal subfield on MRI manually and to compare automatic and manual segmentations for the discrimination of HS types. The T2-weighted images from 14 formalin-fixed age-matched control hippocampi were obtained with 4.7T MRI to evaluate the volume of each subfield at the anatomical level of the hippocampal head, body, and tail. Formalin-fixed coronal sections at the level of the body of 14 control cases, as well as tissue samples from 24 TLE patients, were imaged with a similar high-resolution sequence at 3T. Presurgical three-dimensional (3D) T1-weighted images from TLE went through a FreeSurfer 6.0 hippocampal subfield automatic assessment. The manual delineation with the 4.7T MRI was identified using Luxol Fast Blue stained 10-μm-thin microscopy slides, collected at every millimeter. An additional section at the level of the body from controls and TLE cases was submitted to NeuN immunohistochemistry for neuronal density estimation. All TLE cases were classified according to the International League Against Epilepsy's (ILAE's) HS classification. Manual volumetry in controls revealed that the dentate gyrus (DG)+CA4 region, CA1, and subiculum accounted for almost 90% of the hippocampal volume. The manual 3T volumetry showed that all TLE patients with type 1 HS (TLE-HS1) had lower volumes for DG+CA4, CA2, and CA1, whereas those TLE patients with HS type 2 (TLE-HS2) had lower volumes only in CA1 (p ≤ 0.038). Neuronal cell densities always decreased in CA4, CA3, CA2, and CA1 of TLE-HS1 but only in CA1 of TLE-HS2 (p ≤ 0.003). In addition, TLE-HS2 had a higher volume (p = 0.016) and higher neuronal density (p &lt; 0.001) than the TLE-HS1 in DG + CA4. Automatic segmentation failed to match the manual or histological findings and was unable to differentiate TLE-HS1 from TLE-HS2. Total hippocampal volume correlated with DG+CA4 and CA1 volumes and neuronal density. For the first time, we also identified subfield-specific pathology patterns in the manual evaluation of volumetric MRI scans, showing the importance of manual segmentation to assess subfield-specific pathology patterns

    Subtractive phage display selection from canine visceral leishmaniasis identifies novel epitopes that mimic leishmania infantum antigens with potential serodiagnosis applications

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    Visceral leishmaniasis (VL) is a zoonotic disease that is endemic to Brazil, where dogs are the main domestic parasite reservoirs, and the percentages of infected dogs living in regions where canine VL (CVL) is endemic have ranged from 10% to 62%. Despite technological advances, some problems have been reported with CVL serodiagnosis. The present study describes a sequential subtractive selection through phage display technology from polyclonal antibodies of negative and positive sera that resulted in the identification of potential bacteriophage-fused peptides that were highly sensitive and specific to antibodies of CVL. A negative selection was performed in which phage clones were adhered to purified IgGs from healthy and Trypanosoma cruzi-infected dogs to eliminate cross-reactive phages. The remaining supernatant nonadhered phages were submitted to positive selection against IgG from the blood serum of dogs that were infected with Leishmania infantum. Phage clones that adhered to purified IgGs from the CVL-infected serum samples were selected. Eighteen clones were identified and their reactivities tested by a phage enzyme-linked immunosorbent assay (phage-ELISA) against the serum samples from infected dogs (n 31) compared to those from vaccinated dogs (n 21), experimentally infected dogs with cross-reactive parasites (n 23), and healthy controls (n 17). Eight clones presented sensitivity, specificity, and positive and negative predictive values of 100%, and they showed no crossreactivity with T. cruzi- or Ehrlichia canis-infected dogs or with dogs vaccinated with two different commercial CVL vaccines in Brazil. Our study identified eight mimotopes of L. infantum antigens with 100% accuracy for CVL serodiagnosis. The use of these mimotopes by phage-ELISA proved to be an excellent assay that was reproducible, simple, fast, and inexpensive, and it can be applied in CVL-monitoring programsThis work was supported by grants from the Pró-Reitoria de Pesquisa of UFMG (supported 03/2013), the Instituto Nacional de Ciência e Tecnologia em Nano-Biofarmacêutica (INCT Nano-Biofar), Rede Nanobiotec/Brasil-UFU (CAPES), PRONEX-FAPEMIG (APQ-01019- 09), FAPEMIG (APQ-00496-11 and APQ-00819-12), and CNPq (APQ- 472090/2011-9 and APQ-482976/2012-8). E.A.F.C. and L.R.G. are recipients of grants from CNPq. M.A.C.-F. is the recipient of a grant from FAPEMIG/CAPE

    Prospective Analysis of Food Consumption and Nutritional Status and the Impact on the Dietary Inflammatory Index in Women With Breast Cancer During Chemotherapy

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    Considering the implications of adverse effects of chemotherapy (CT) and the potential impact of diet on patients’ recovery, this study aimed to prospectively evaluate the association between the consumption of food groups, patients’ Dietary Inflammatory Index (DII®) scores, and their nutritional status. Anthropometric and dietary assessments of 55 women with breast cancer (BC) were performed at three time points. T0 is the time point after the first CT cycle, T1 is the time point after the intermediate CT cycle, and T2 is the time point after the last CT cycle. We identified a significant increase in weight, body mass index, and waist circumference during CT. Consumption of poultry and eggs was higher in T1 when compared to T2, while consumption of total fruit and total vegetables was higher at T0 compared to T1 and T2. The diet became more pro-inflammatory over the course of treatment (X2(2) = 61.127), and was related to higher abdominal adiposity. Total fruit (T0: R2 = 0.208, T1: R2 = 0.095, T2: R2 = 0.120) and total vegetable consumption (T0: R2 = 0.284, T1: R2 = 0.365, T2: R2 = 0.580) predicted DII® change at the three-time points. Meanwhile, consumption of total grains was significantly associated only with T1 (R2 = 0.084) and T2 (R2 = 0.118), and consumption of simple sugars was significantly associated only with T0 (R2 = 0.137) and T1 (R2 = 0.126). Changes in food consumption led to an increase in the inflammatory profile of the diet, suggesting the necessity to improve the guidelines during and after CT. These results reinforce the need to promote healthier eating practices in concert with maintaining a healthy nutritional status in women with BC treated with C
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