Anticorpos Anti-Receptor da TSH na Doença de Graves

Neste trabalho os AA avaliam a sensibilidade, especificidade e valor predictivo do doseamen to dos anticorpos anti-receptor da TSH (TRAb) no diagnóstico da doença de Graves. A população estudada incluiu 80 doentes com doença de Graves recentemente diagnosticada e sem tratamento prévio (grupo 1), 63 doentes com outras patologias tiroideias (grupo II) e 60 indivíduos sem patologia tiroideia (grupo III). Utilizaram uma técnica de radioreceptor, o kit TRAK Henning, que considera positividade> 14 U TRAb L, negatividade 9 e zona cinzenta entre estes 2 valores. No grupo 1, 11 doentes tinham TRAb negativo e 7 situavam-se na zona cinzenta. No grupo II apenas 2 doentes tinham TRAb de 9 e todos os indivíduos do grupo controlo tinham TRAb negativo. Para efeito estatístico foram excluidos os doentes com valores na zona cinzenta. Os valores de sensibilidade e especificidade para o método ensaiado foram respectivamente de 84,5° o e 10000. O valor predictivo foi de 1000 o, o que permite afirmar com segurança que um doente com hipertiroidismo e TRAb positivo tem doença de Graves.

Anti-Phospholipase A2 Receptor Antibodies in the Diagnosis of Idiopathic Membranous Nephropathy

Circulating anti-phospholipase A2 receptor antibodies (anti-PLA2R) have been described in 70% to 80% of the patients with idiopathic membranous nephropathy (iMN), but not in patients with secondary membranous nephropathy or other glomerular diseases. The goal of this study was to evaluate the sensitivity and specificity of the assay for anti-PLA2R in the diagnosis of iMN. Anti-PLA2R IgG, Elisa and immunofluorescence tests were used to detect circulating anti-PLA2R. These tests were applied in 53 patients who had a kidney biopsy. Of these, 38 had histological diagnosis of membranous nephropathy (MN) and the remaining had other glomerular diseases. The MN was classified as idiopathic in 33 patients after clinical exclusion of secondary causes. Anti-PLA2R were positive in 57.6% of the patients with iMN. All patients with secondary membranous nephropathy or other glomerular diseases did not show circulating anti-PLA2R. The sensitivity was 57.6% (CI 39.2-74.5) and specificity 100% (CI 47.8-100), AUC 0.788; p < 0.0001 for the detection of iMN. 71.4% of the iMN patients that tested negative for anti-PLA2R were in partial or complete remission. The detection of anti-PLA2R in the studied population had a specificity of 100% for the iMN diagnosis. Prior treatments seem to make the test negative and contribute to a lower sensitivity.

Hipotiroidismo Associado a Anticorpos Anti-Receptor da Hormona TSH com Ação Bloqueadora Determinada In Vitro

Thyroid-stimulating hormone-receptor autoantibodies normally causes hyperthyroidism. However, they might have blocking activity causing hypothyroidism. A 11-year-old girl followed due to type 1 diabetes mellitus, celiac disease and euthyroid lymphocytic thyroiditis at diagnosis. Two years after the initial evaluation, thyroid-stimulating hormone was suppressed with normal free T4; nine months later, a biochemical evolution to hypothyroidism with thyroid-stimulating hormone-receptor autoantibodies elevation was seen; the patient remained always asymptomatic. Chinese hamster ovary cells were transfected with the recombinant human thyroid-stimulating hormone -receptor, and then exposed to the patient's serum; it was estimated a 'moderate' blocking activity of these thyroid-stimulating hormone-receptor autoantibodies, and concomitantly excluded stimulating action. In this case, the acknowledgment of the blocking activity of the serum thyroid-stimulating hormone-receptor autoantibodies, supported the hypothesis of a multifactorial aetiology of the hypothyroidism, which in the absence of the in vitro tests, we would consider only as a consequence of the destructive process associated to lymphocytic thyroiditis.

Development of an affinity pair “Tag-Receptor” for recombinant protein expression and purification

Dissertação apresentada para a obtenção do Grau de Mestre em Biotecnologia, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Glucocorticoid-induced tumor necrosis factor receptor expression in patients with cervical human papillomavirus infection

Introduction The progression of human papillomavirus (HPV) infection in the anogenital tract has been associated with the involvement of cells with regulatory properties. Evidence has shown that glucocorticoid-induced tumor necrosis factor receptor (GITR) is an important surface molecule for the characterization of these cells and proposes that GITR ligand may constitute a rational treatment for many cancer types. We aimed to detect the presence of GITR and CD25 in cervical stroma cells with and without pathological changes or HPV infection to better understand the immune response in the infected tissue microenvironment. Methods We subjected 49 paraffin-embedded cervical tissue samples to HPV DNA detection and histopathological analysis, and subsequently immunohistochemistry to detect GITR and CD25 in lymphocytes. Results We observed that 76.9% of all samples with high GITR expression were HPV-positive regardless of histopathological findings. High GITR expression (77.8%) was predominant in samples with ≥1,000 RLU/PCB. Of the HPV-positive samples negative for intraepithelial lesion and malignancy, 62.5% had high GITR expression. High GITR expression was observed in both carcinoma and high-grade squamous intraepithelial lesion (HSIL) samples (p = 0.16). CD25 was present in great quantities in all samples. Conclusions The predominance of high GITR expression in samples with high viral load that were classified as HSIL and carcinoma suggests that GITR+ cells can exhibit regulatory properties and may contribute to the progression of HPV-induced cervical neoplasia, emphasizing the importance of GITR as a potential target for immune therapy of cervical cancer and as a disease evolution biomarker.

Síntese de moléculas contendo a unidade de piperazina como potenciais agentes antipsicóticos

Tese de Doutoramente em Ciências (área de especialização em Química).

Influence of angiotensin II receptor subtypes of the paraventricular nucleus on the physiological responses induced by angiotensin II injection into the medial septal area

OBJECTIVE: We determined the effects of losartan and PD 123319 (antagonists of the AT1 and AT2 angiotensin receptors, respectively), and [Sar¹, Ala8] ANG II (a relatively peptide antagonist of angiotensin receptors) injected into the paraventricular nucleus (PVN) on water and 3% NaCl intake, and the diuretic, natriuretic, and pressor effects induced by administration of angiotensin II (ANG II) into the medial septal area (MSA) of conscious rats. METHODS: Holtzman rats were used . Animals were anesthetized with tribromoethanol (20 mg) per 100 grams of body weight, ip. A stainless steel guide cannula was implanted into the MSA and PVN. All drugs were injected in 0.5-mul volumes for 10-15 seconds. Seven days after brain surgery, water and 3% NaCl intake, urine and sodium excretion, and arterial blood pressure were measured. RESULTS: Losartan (40 nmol) and [Sar¹, Ala8] ANG II (40 nmol) completely eliminated whereas PD 123319 (40 nmol) partially blocked the increase in water and sodium intake and the increase in arterial blood pressure induced by ANG II (10 nmol) injected into the MSA. The PVN administration of PD 123319 and [Sar¹, Ala8] ANG II blocked whereas losartan attenuated the diuresis and natriuresis induced by MSA administration of ANG II. CONCLUSION: MSA involvement with PVN on water and sodium homeostasis and arterial pressure modulation utilizing ANGII receptors is suggested.

Effect of arginine vasopressin on the canine epicardial coronary artery: experiments on V1-receptor-mediated production of nitric oxide

OBJECTIVE: To determine whether arginine vasopressin releases endothelium-derived nitric oxide (EDNO) from the epicardial coronary artery. METHODS: We studied segments of canine left circumflex coronary arteries suspended in organ chambers to measure isometric force. The coronary artery segments were contracted with prostaglandin F2alpha (2 x 10-6M) and exposed to a unique, strong arginine vasopressin concentration (10-6M) or titrated concentrations (10-9 a 10-5 M). RESULTS: The unique dose of arginine vasopressin concentration (10-6M) induced transient, but significant (p<0.05), relaxation in arterial segments with endothelium, and an increase, not significant, in tension in arteries without endothelium. Endothelium-dependent relaxation to arginine vasopressin was inhibited by Ng-monomethyl-L-arginine (L-NMMA, 10-5M) or N G-nitro-L-arginine (L-NOARG) (10-4M), 2 inhibitors of nitric oxide synthesis from L-arginine. Exogenous L-arginine (10-4M), but not D-arginine (10-4M), reversed the inhibitory effect of L-NMMA on vasopressin-mediated vasorelaxation. Endothelium dependent relaxation to vasopressin was also reversibly inhibited by the vasopressin V1-receptor blocker d(CH2)5Try(Me) arginine vasopressin (10-6M) (n=6, P<0.05). CONCLUSION: Vasopressin acts through V1 endothelial receptors to stimulate nitric oxide release from L-arginine.

O polimorfismo A1166C do receptor tipo 1 da angiotensina II no infarto agudo do miocárdio

RESUMO OBJETIVO:Avaliar a associação do polimorfismo A1166C do gene do receptor AT1 da angiotensina II (AT1R) com o infarto agudo do miocárdio e a severidade da doença arterial coronariana. MÉTODOS: Estudo prospectivo, transversal de 110 pacientes com infarto agudo do miocárdio submetidos à angiografia coronariana com lesão significante (> 50%) avaliada por três critérios de severidade: número de vasos lesados, morfologia da placa aterosclerótica e escore de risco coronariano. Sem lesões coronarianas 104 indivíduos controles. O polimorfismo A1166C do gene do AT1R foi determinado pela reação em cadeia da polimerase no DNA dos leucócitos do sangue periférico. Os fatores de risco coronariano clássicos foram analisados em todos os indivíduos. RESULTADOS: Na estratificação dos genótipos em relação aos fatores de risco apenas o tabagismo teve predominância nos heterozigotos AC (p = 0,02). A freqüência dos genótipos nos pacientes infartados foi de AA = 54,5%; AC = 35,5% e CC = 10%, sendo similar e não significativa em relação aos controles (p = 0,83). Não houve aumento do risco de infarto agudo do miocárdio nas comparações dos genótipos CC vs AA (OR = 1,35; IC-95% = 0,50 - 3,59), AC vs AA (OR = 1,03; IC-95% = 0,58 - 1,84 e AA+AC vs AA (OR = 1,33; IC-95% = 0,51 - 3,45). Nenhum dos critérios de severidade teve associação significativa com os genótipos. CONCLUSÃO: Os nossos resultados indicam não haver associação do polimorfismo A1166C do AT1R com o infarto agudo do miocárdio e nem com a severidade da doença arterial coronariana segundo nossos resultados.

Polimorfismo del general del receptor de vitamina D y densidad mineral ósea en mujeres porstmenopáusicas sanas u osteoporóticas de la Ciudad de Córdoba

La osteoporosis es considerada en la actualidad como uno de los problemas de salud humana más preocupantes en varias partes del mundo. El incremento de las expectativas de la vida promedio de los individuos tiende a incrementar el número de casos, lo cual hace que el problema pueda ser mayor en el futuro. Esta enfermedad compleja, relacionada con la edad, se caracteriza por una disminución de la densidad mineral ósea (conocida con la sigla inglesa BMD que significa bone mineral density), rigidez muscular, inestabilidad postural y alteraciones que conducen a fracturas o riesgo de fracturas. Una BMD baja parecería ser el principal factor de riesgo para el desarrollo de la osteoporosis y fracturas relacionadas. La enfermedad se confirma cuando el valor de BMD se encuentra 2,5 desviaciones estándar por debajo de la BMD correspondiente a individuos normales jóvenes. La densidad mineral ósea promedio es mayor en el hombre que en la mujer; se incrementa durante la adolescencia, se mantiene constante en la adultez. (...) (...) En la osteoporosis, el metabolismo del calcio también está alterado, de allí que el gen de VDR es considerado como uno de los factores a tener en cuenta en el desarrollo de esta enfermedad. El gen del VDR humano está localizado en el cromosoma 12, está constituido por 11 exones dispuestos en 75 Kb de ADN que da origen a un transcripto ARNm de aproximadamente 4800 nucleótidos que codifican por una proteína de 427 aa. El exón 9 es el más grande y contiene una larga región 3´ no traducida que produce un importante polimorfismo de secuencias en la región no codificante. Objetivos específicos: 1. Establecer la correlación entre el genotipo del receptor de vitamina D y la densidad mineral ósea en mujeres postmenopáusicas sanas y osteoporóticas en una muestra de población de la ciudad de Córdoba. 2. Analizar las frecuencias genotípicas del gen del receptor de vitamina D para Bsm-1 en mujeres sanas y osteoporóticas en relación a la edad y a los años después de la menopausia. 3. Determinar la relación entre marcadores óseos bioquímicos, el status de vitamina D y el genotipo Bsm-1. 4. Interpretar la utilidad del estudio del genotipo del receptor de vitamina D en el diagnóstico y pronóstico del desarrollo de la osteoporosis en la población femenina de la ciudad de Córdoba.

O polimorfismo VNTR no gene codificador do antagonista do receptor da interleucina-1 está associado com a doença arterial coronariana

FUNDAMENTO: A Doença Arterial Coronariana (DAC) é a aterosclerose das artérias coronárias que transportam o sangue para o coração. A aterosclerose é uma doença inflamatória. As variações gênicas das citocinas - como as associadas à família IL1 - fazem parte da patogênese da aterosclerose. OBJETIVO: O objetivo deste estudo foi determinar a relação entre os polimorfismos da família IL1 (VNTR do IL1RN, posições -511 e +3953 do IL1B) e a DAC na população turca. MÉTODOS: Um total de 427 indivíduos foram submetidos à angiografia coronariana e em seguida divididos da seguinte forma: 170 no grupo controle e 257 no grupo de pacientes com DAC. Os sujeitos com DAC foram divididos em dois subgrupos: 91 no grupo de Doença Coronariana em um único vaso (Single Vessel Disease - SVD) e 166 no grupo Doença Coronariana em múltiplos vasos (Multiple Vessel Disease - MVD). Os genótipos de IL1RN e IL1B (-511, +3953) foram determinados por reação em cadeia da polimerase (RCP), seguida de análise da digestão por enzima de restrição. RESULTADOS: Não foram observadas diferenças significantes nas distribuições de genótipos de IL1RN e IL1B (-511 e +3953) entre os sujeitos com DAC e os controles, ou entre sujeitos com MVD e controles. No entanto, observou-se uma relação significante no genótipo IL1RN 2/2 entre sujeitos portadores de SVD e controles (P= 0,016, x2: 10,289, OR: 2,94IC 95% 1,183 - 7,229). Tampouco foi observada diferença estatisticamente significante nas freqüências dos alelos de IL1RN e IL1B (-511 e +3953) entre os sujeitos com DAC e controles, os sujeitos com MVD e controles, ou ainda os sujeitos SVD e controles. CONCLUSÃO: Não foi observada nenhuma relação na freqüência alélica e nem na distribuição genotípica dos polimorfismos de IL1RN e IL1B entre sujeitos com DAC e grupos controle. No entanto, o genótipo IL1RN 2/2 pode representar um fator de risco para sujeitos com SVD na população turca.

Diseño del subsistema RF para el receptor SAR biestático en banda-C SABRINA

Este proyecto tiene como objetivo diseñar un nuevo receptor SAR biestático para el sistema SABRINA (SAR Bistatic fixed Receiver for INterferometric Applications) caracterizando el sistema que ya existía. El nuevo dispositivo deberá cumplir con las características y requisitos del escenario teniendo en cuenta la potencia recibida y el ruido de cuantificación de la tarjeta digitalizadora. Con este fin se introducen previamente conocimientos de teoría RADAR y SAR. Además, se deberá compactar al máximo el sistema para conseguir un receptor autocontenido que facilite su traslado. Para tal fin se ha incorporado a la caja del receptor un sintetizador programable que actúa de oscilador local de las cadenas de recepción y una fuente de alimentación que provee la tensión a todos los componentes activos del dispositivo. Por otra parte el proyecto ilustra las diferentes campañas de experimentos que se han realizado durante el periodo de trabajo.

Melanoma patients respond to a cytotoxic T lymphocyte-defined self-peptide with diverse and nonoverlapping T-cell receptor repertoires.

HLA-A2+ melanoma patients develop naturally a strong CD8+ T cell response to a self-peptide derived from Melan-A. Here, we have used HLA-A2/peptide tetramers to isolate Melan-A-specific T cells from tumor-infiltrated lymph nodes of two HLA-A2+ melanoma patients and analyzed their TCR beta chain V segment and complementarity determining region 3 length and sequence. We found a broad diversity in Melan-A-specific immune T-cell receptor (TCR) repertoires in terms of both TCR beta chain variable gene segment usage and clonal composition. In addition, immune TCR repertoires selected in the patients were not overlapping. In contrast to previously characterized CD8+ T-cell responses to viral infections, this study provides evidence against usage of highly restricted TCR repertoire in the natural response to a self-differentiation tumor antigen.

CD8 kinetically promotes ligand binding to the T-cell antigen receptor.

The mechanism of CD8 cooperation with the TCR in antigen recognition was studied on live T cells. Fluorescence correlation measurements yielded evidence of the presence of two TCR and CD8 subpopulations with different lateral diffusion rate constants. Independently, evidence for two subpopulations was derived from the experimentally observed two distinct association phases of cognate peptide bound to class I MHC (pMHC) tetramers and the T cells. The fast phase rate constant ((1.7 +/- 0.2) x 10(5) M(-1) s(-1)) was independent of examined cell type or MHC-bound peptides' structure. Its value was much faster than that of the association of soluble pMHC and TCR ((7.0 +/- 0.3) x 10(3) M(-1) s(-1)), and close to that of the association of soluble pMHC with CD8 ((1-2) x 10(5) M(-1) s(-1)). The fast binding phase disappeared when CD8-pMHC interaction was blocked by a CD8-specific mAb. The latter rate constant was slowed down approximately 10-fold after cells treatment with methyl-beta-cyclodextrin. These results suggest that the most efficient pMHC-cell association route corresponds to a fast tetramer binding to a colocalized CD8-TCR subpopulation, which apparently resides within membrane rafts: the reaction starts by pMHC association with the CD8. This markedly faster step significantly increases the probability of pMHC-TCR encounters and thereby promotes pMHC association with CD8-proximal TCR. The slow binding phase is assigned to pMHC association with a noncolocalized CD8-TCR subpopulation. Taken together with results of cytotoxicity assays, our data suggest that the colocalized, raft-associated CD8-TCR subpopulation is the one capable of inducing T-cell activation.