La técnica de polarización fluorescente para el diagnóstico de Brucella en Chaetophractus villosus / Technique of fluorescence polarization for the diagnosis of Brucella in Chaetophractus villosus / A técnica de polarização fluorescente para o diagnóstico de Brucella em Chaetophractus villosus

La brucelosis es una enfermedad muy extendida por todo el mundo. El diagnóstico se realiza mediante el uso de diferentes técnicas, entre ellas el aislamiento del agente etiológico o por serología detectando anticuerpos específicos. Todos estos métodos están estandarizados y validados en general para las distintas especies animales de interés zootécnico. En animales silvestres pueden utilizarse los mismos procedimientos serológicos, pero cada uno debe ser validado para la especie animal estudiada. El objetivo de este trabajo fue comprobar si la técnica de Polarización Fluorescente (FPA) utilizada para la determinación de anticuerpos contra Brucella en bovinos puede ser usada para el diagnóstico de Brucella en el armadillo (Chaetophractus villosus). Para ello se tomaron 150 muestras de sangre de Chaetophractus villosus. Veinticuatro muestras fueron positivas por medio de las técnicas de antígeno bufferado en placa, seroaglutinación lenta en tubo, 2-mercaptoetanol y fijación del complemento. Las mismas muestras resultaron positivas a la técnica de Polarización Fluorescente, estableciéndose un límite de corte de 82 mP. El índice Kappa registrado fue de 1 para todos los tests de diagnóstico comparados con FPA (IC: 0,84-1).

Brucellosis is a disease widespread throughout the world. The diagnosis is made through the use of different techniques including the isolation of the etiological agent or by serology detecting specific antibodies. All these methods are standardized and validated in general for animal species of zoo-technical interest. In wild animals, serological procedures may be used, but each should be validated for the particular animal species studied. The objective of this work was to verify if the technique of Fluorescent Polarization used for the determination of antibodies against Brucella in ruminants can be used for the diagnosis of Brucella in Chaetophractus villosus. To this aim, s 150 blood samples of Chaetophractus villosus were taken. Twenty-four samples were positive by the techniques of Antigen Buffered in Plate, serum agglutination test (SAT), 2-mercaptoethanol (2-ME) agglutination test and complement fixation test (CFT). The same samples were also positive by Fluorescent Polarization, and a cut-off limit of 82 mP was established. The KAPPA index was 1 for all diagnostic tests compared to FPA (CI: 0.84-1).

A brucelose é uma doença muito espalhada pelo mundo. O diagnóstico é feito por meio de diferentes técnicas, incluindo o isolamento do agente etiológico ou por sorologia detectando anticorpos específicos. Todos esses métodos são padronizados e validados em geral para diferentes espécies animais de interesse zootécnico. Em animais silvestres podem ser utilizados os mesmos métodos serológicos, mas cada um tem de ser validado para a espécie de animal estudada. O objectivo deste estudo foi testar se a técnica de Polarização Fluorescente utilizada para a determinação de anticorpos contra Brucella em bovinos pode ser utilizada para o diagnóstico de Brucella em tatu (Chaetophractus villosus). Para isso, 150 amostras de sangue de Chaetophractus villosus foram coletadas. Vinte e quatro amostras foram positivas por técnicas de antígeno bufferado em placa, soroaglutinação lenta em tubo, 2-mercaptoetanol e fixação do complemento. As mesmas amostras foram positivas para a técnica de Polarização Fluorescente, estabelecendo um limite de corte de 82 mP. O índice Kappa registrado foi de 1 para todos os testes de diagnóstico em comparação com FPA (CI: 0,84-1).

Brucelosis en el zorro gris pampeano (Pseudalopex gymnocercus) en la provincia de La Pampa (Argentina) / Brucelosis in the grey fox of the pampas (Pseudalopex gymnocercus) in La Pampa province (Argentina)

Brucella abortus (Br abortus) es una de las principales causas de abortos y pérdidas reproductivas en el ganado bovino. Los fetos abortados y sus fluidos fetales son la mayor fuente de infección. Es así como la enfermedad puede llegar a animales silvestres cuando ingieren esos tejidos. El objetivo de este trabajo fue determinar la prevalencia serológica de brucelosis en el zorro gris pampeano (Pseudalopex gymnocercus). Se tomaron muestras de sangre de 41 zorros de la región centro-este de la provincia de La Pampa, Argentina. Para determinar la presencia de anticuerpos específicos contra Br abortus se utilizaron las Pruebas de Polarización de la Fluorescencia (FPA), Seroaglutinación en Microplaca (SAP) y Seroaglutinación en Microplaca con 2-mercaptoetanol (2-ME). Sobre un total de 41 sueros procesados por FPA, en 7 (17,1%) se detectaron anticuerpos contra Br abortus. Sólo 34 sueros fueron analizados por las pruebas de SAP y 2-ME, encontrando 5 (14,7%) y 4 (11,8%) muestras positivas, respectivamente. Los resultados permiten inferir que el zorro gris pampeano es susceptible a infectarse con Br. abortus a una tasa de incidencia importante. Es necesario realizar futuros estudios para establecer el rol del zorro en la transmisión de la enfermedad y sus consecuencias en esta especie.

Brucellosis is produced by several species of Brucella. Brucella abortus causes abortion and reproductive loss in bovine cattle. In the epidemiology of brucellosis, aborted fetus and their fetal fluids are the main source of infection and dissemination. Although the biological cycle and the disease consequences to domestic cattle have been widely studied, it is not the case with wild fauna. The objective of this study was to determine the serologic prevalence to brucellosis in the grey fox of the pampas (Pseudalopex gymnocercus). To that purpose, 41 foxes were sampled in the centre-east area of La Pampa province (Argentina). Blood samples for serologic studies were collected. A test of agglutination in microplate (SAP), another SAP with the addition of 2-mercapto-etanol (2-ME) and a test of polarization of the fluorescence (FPA) were used for the diagnosis of antibodies against Brucella abortus. For this, 17.1%, 14.7% and 11.8% was the prevalence found by FPA, SAP and SAP with 2-ME. More studies will be necessary to know the role of foxes in disease transmission and maintenance as well as the consequence of the diseases in foxes.

Mecanismo de ação do metotrexato e avalição clínica de sua associação com a cloroquina no controle de artrite reumatóide juvenil / Methotrexate action mechanism and clinical assessment of its association with chroquine in juvenile rheumatoid arthritis control

Estudaram-se a eficácia clínica do uso do metotrexato (MTX) e sua associação com a cloroquina (CQ) para o controle da artrite reumatóide juvenil, e o mecanismo bioquímico de inibição celular do MTX. A resposta clínica foi obtida através da avaliação de dor, edma e número de articulações acometidas;a avaliação cinética do MTX no plasma e urina, bem como o estudo dos indicadores de atividade da doença: proteína C-reativa (PCR), substância amilóide A (SAA), velocidade de hemossedimentação (VHS), fibrinogênio e "alfa"-glicoproteína ácida foram feitos em pacientes, cuja idade variou de 12 a 25 anos. Todos os pacientes apresentaram relativo controle da doença e nao mostraram diferença significativa, com relação...

Deconvolution of the fluorescence spectra into its component Gaussians: a method to analyze the binding of coumarin to bovine serum albumin.

7-N,N-Diethylamino-4-methylcoumarin, (cou-1), a readily available laser dye binding to bovine serum albumin (BSA), at room temperature has been studied by steady state fluorescence spectroscopy. Existing methods of analysis of the binding to obtain the binding parameters are based on the change in fluorescence intensity at a particular wavelength. These methods are not convenient when there is a gradual shift in the emission maxima for increasing protein concentration. In this paper we present a method to obtain the binding constants of cou-1 to BSA using a Windows '95 based package to deconvolute the asymmetrical spectrum (fluorescence intensity versus wave number curve) into two Gaussians, each corresponding to the binding of the fluorophore to a particular site. This method is convenient to analyze the binding constant data and obtain the binding parameters of each binding site, and can also provide information about the microenvironment of each site, relating micropolarity and microviscosity.

Hormonal-induced changes on lipidi composition and DPH fluorescence anisotropy of erithrocyte ghost from pre-and postmenopausal women

Fluorescence anisotropy determination were performed on hypotonically lysed red blood cells from 12 healthy, free living, premenopausal and 10 postmenopausal women fed a self-selected diet. Fatty acid composition of phospholipids and cholesterol esters, lipid/lipid and lipid/protein ratios were also determined in erythrocyte ghosts along the menstrual cycle or during hormonal replacemente therapy. The postmenopausal women were treated with transdermal 17-beta estradiol (approx. delivery rate of 50 mug/day) for a 5-week period and with a combination of percutaneous administration of estradiol and orally administered medroxyprogesterone acetate (5 mg/day) for 5 weeks more. Premenopausal women were studied in the mid-follicular and mid-luteal phases of their menstrual cycles. Membrane fluidity in cells from the luteal phase was greater than that observed in the follicular phase. After estradiol treatment, postmenopausal women exhibited a significant raise in the fluorescence anisotropy. The association with progesterone prevented the estrogen-induced increase of the anisotropy values. Estrogen administration also produced an increment in the relative content of cholesterol and membrane proteins that was reverted by progesterone addition. Changes induced by estradiol treatment in the fatty acid pattern of phospholipids and cholesterol esters were characterized by an increment in the monoenoic/saturated fatty acid ratio and linoleic relative content, with a concomitant decrease in the proportion of arachidonic and docosatetraenoic acids. These results suggest that the modification of the desaturase activities may be involved in a mechanism by which these hormonal-induced changes take place. The present study demonstrated that human erythrocyte fluidity is under hormonal control subjected through changes in the proportion and quality of the membrane lipids.