Objetivo: estudiar la frecuencia de positividad de las pruebas serológicas en pacientes con biopsias compatible con enfermedad celiaca. Material y métodos: estudio transversal. Se incluyeron pacientes con biopsia duodenal histológicamente compatible con enfermedad celiaca y determinación de anticuerpos antigliadina, antiendomisio y antitransglutaminasa IgA. Definimos como caso de enfermedad celiaca a quienes tuvieran biopsia positiva y anticuerpos antiendomisio y/o antitransglutaminasa positivos. Resultados: 31 pacientes fueron incluidos de los cuales 6 fueron antiendomisio positivo, 5 fueron antitransglutaminasa positivo y antigliadina fue positivo en 14. Por lo tanto de 31 pacientes con cambios histológicos compatibles con enfermedad celiaca sólo 10 tuvieron serología diagnóstica. Sólo uno de los pacientes tuvo positividad tanto para antitransglutaminasa como para antiendomisio. Conclusiones: a) encontramos que la mayoría de biopsias de duodeno con un cuadro histológico sugerente de enfermedad celiaca no se corresponden con serología diagnóstica de esta enfermedad; b) encontramos baja coincidencia en la positividad serológica entre antiendomisio y antitransglutaminasa. / Objective: to study the frequency of positive serology for celiac disease (CD) in patients with duodenal biopsies suggestive of this disease. Material and methods: cross sectional study. We included patients with duodenal biopsies histologically compatible with CD and antigliadin, antiendomysial and IgA antitransglutaminase antibodies. We defined a “case” of CD if there was a positive biopsy and either antiendomisial or antitransglutaminase positive antibodies. Results: thirty one patients were included in our study. Six were antiendomysial positive and 5 antitransglutaminase positive while the antigliadin was positive in 14 cases. Therefore, out of 31 patients only 10 had a serology compatible with CD and only one had positive both antibodies, antiendomysial and antitransglutaminase. Conclusions: a) we have found that most of the duodenal biopsies compatible with CD are not diagnosed with positive serology; and b) we found a low correlation between serological diagnostic tests.

Os efeitos clastogênicos causados por diferentes cepas Ureaplasma urealyticum e por cepas do gênero Mycoplasma foram avaliados \"in vitro\", utilizando-se culturas temporárias de linfócitos humanos. Inibições, total ou parcial da mitose foram produzidos pelos sorotipos II, III e X de Ureaplasma urealyticum, independentemente das concentrações dos inóculos de micoplasmas utilizados. Já os sorotipos I, VII e XII do Ureaplasma urealyticum, a cepa Mycoplasma hominis ATCC 23114 e a cepa Mycoplasma pneumoniae foram influenciadas pela concentração dos micoplasmas. Mitoses alteradas foram observadas nas cepas Ureaplasma urealyticum VIII, IX e X. A maior frequência de alterações foram de gaps cromatídicos e quebras cromatídicas. Os resultados obtidos neste modelo experimental \"in vitro\" revelaram haver comportamentos diferentes entre os vários sorotipos de Ureaplasma urealyticum e entre espécies do gênero Mycoplasma. Essas diferenças observadas, \"in vitro\", poderão de alguma forma contribuir para melhor compreensão dos efeitos da colonização desses microorganismos em humanos. / Clastogenic effect caused by different strains of Ureaplasma urealyticum and by strains of Mycoplasma sp were evaluated in vitro by using temporary cultures of human linphocytes. Mitotic inhibitions, either total or partial were produced by serotypes lI, III and X of Ureaplasma urealyticum, indenpendently of the concentration of microorganisms used. Otherwise, the kind of clastogenic effect of Ureaplasma urealyticum of serotypes I, VII and XII, Mycoplasma hominis strain 23144 and Mycoplasma pneumoniae varied with the different concentrations of these mycoplasmas used in the test. Mitotic alterations were observed in Ureaplasma urealyticum of sorotypes VII, IX and X. Cromatidic gaps and cromatidic rupture were the most frequent kind of alterations evidenced. The results obtained in the present in vitro experiment revealed that the occurence of different kind of clastogenic effect depends on the serotypes of Ureaplasma urealyticum and on the strains of Mycoplasma sp. The variability of the effect obtained will contribute to the better comprehension of the effects of colonization of these microorganisms in humans and stimulate future in vivo investigation.

Os efeitos clastogênicos causados por diferentes cepas Ureaplasma urealyticum e por cepas do gênero Mycoplasma foram avaliados \"in vitro\", utilizando-se culturas temporárias de linfócitos humanos. Inibições, total ou parcial da mitose foram produzidos pelos sorotipos II, III e X de Ureaplasma urealyticum, independentemente das concentrações dos inóculos de micoplasmas utilizados. Já os sorotipos I, VII e XII do Ureaplasma urealyticum, a cepa Mycoplasma hominis ATCC 23114 e a cepa Mycoplasma pneumoniae foram influenciadas pela concentração dos micoplasmas. Mitoses alteradas foram observadas nas cepas Ureaplasma urealyticum VIII, IX e X. A maior frequência de alterações foram de gaps cromatídicos e quebras cromatídicas. Os resultados obtidos neste modelo experimental \"in vitro\" revelaram haver comportamentos diferentes entre os vários sorotipos de Ureaplasma urealyticum e entre espécies do gênero Mycoplasma. Essas diferenças observadas, \"in vitro\", poderão de alguma forma contribuir para melhor compreensão dos efeitos da colonização desses microorganismos em humanos. / Clastogenic effect caused by different strains of Ureaplasma urealyticum and by strains of Mycoplasma sp were evaluated in vitro by using temporary cultures of human linphocytes. Mitotic inhibitions, either total or partial were produced by serotypes lI, III and X of Ureaplasma urealyticum, indenpendently of the concentration of microorganisms used. Otherwise, the kind of clastogenic effect of Ureaplasma urealyticum of serotypes I, VII and XII, Mycoplasma hominis strain 23144 and Mycoplasma pneumoniae varied with the different concentrations of these mycoplasmas used in the test. Mitotic alterations were observed in Ureaplasma urealyticum of sorotypes VII, IX and X. Cromatidic gaps and cromatidic rupture were the most frequent kind of alterations evidenced. The results obtained in the present in vitro experiment revealed that the occurence of different kind of clastogenic effect depends on the serotypes of Ureaplasma urealyticum and on the strains of Mycoplasma sp. The variability of the effect obtained will contribute to the better comprehension of the effects of colonization of these microorganisms in humans and stimulate future in vivo investigation.

Chez les vertébrés gnathostomes, le système immunitaire repose en grande partie sur les lymphocytes T qui se développent dans un organe conservé évolutivement : le thymus. Chez les mammifères, cet organe constitue une cible privilégiée pour les œstrogènes. La question soulevée ici est donc de savoir si c’est également le cas chez les poissons téléostéens. Dans ce but, la distribution des différents sous-types de récepteurs aux œstrogènes a d’abord été étudiée dans le contexte d’une description de l’anatomie fonctionnelle du microenvironnement thymique. Par la suite, l’expression de gènes relatifs à la fonction thymique et aux différents sous-types de lymphocyte T a été analysée dans le thymus, le rein-antérieur et la rate de bars exposés au 17ß-œstradiol. De plus, la capacité de flambée oxydative a été évaluée sur des leucocytes du rein-antérieur et de rate à la suite d’expositions in vivo et in vitro. Finalement, la variation du nombre de thymocytes a été examinée sur des bars capturés durant trois ans. La thèse fournit de nouvelles connaissances concernant l’évolution des fonctions immunomodulatrices des œstrogènes sur la différenciation des cellules T. En effet, en plus d’une organisation morpho-fonctionnelle fortement conservée, la distribution des sous-types de récepteurs aux œstrogènes ainsi que les effets œstrogéniques apparaissent conservés au cours de l’évolution. Nos résultats suggèrent que, chez le bar comme chez les mammifères, les œstrogènes (1) stimulent une voie alternative de maturation des lymphocytes T ayant des propriétés similaires aux cellules immunitaires innées, (2) augmentent la tolérance immunitaire et (3) régulent la plasticité du thymus. / Jawed vertebrates have developed an efficient adaptive immune system partly based on T lymphocytes. They develop in an evolutionarily conserved organ, the thymus. In mammals, endogenous oestrogens are well known to regulate thymus function and plasticity. The question is, therefore, whether this is also the case in lower vertebrates, such as teleosts. To achieve these aims, firstly the distribution of oestrogen receptor subtypes was investigated on the background of a detailed description of the functional anatomy of the thymic microenvironment. Secondly, thymic function- and T cell-related gene expression was analysed in the thymus, the head-kidney and the spleen of sea bass exposed to 17ß-oestradiol. Moreover, the oxidative burst capacity in the two latter organs was evaluated in vivo and in vitro in leucocytes of the head-kidney and spleen following exposure to oestrogen. Eventually, age- and size-dependent variations in thymocyte number were examined in sea bass caught at various time points over three years. The thesis provides new insights into the evolution of the immunomodulatory function of oestrogen with respect to the thymic and peripheral T cell differentiation in vertebrates. As a matter of fact, in addition to a highly conserved morpho-functional organisation, the distribution of oestrogen receptor subtypes as well as the oestrogenic effects appear to be evolutionarily conserved. Our results suggest that in sea bass, similar to mammals, oestrogen (1) stimulates a thymic alternative pathway of T cell maturation with innate-like properties, (2) enhances immune tolerance by promoting Treg differentiation, and (3) actively regulate thymic plasticity.

HTLV-I is the first discovered human retrovirus and a causative agent of both adult T-cell leukemia (ATL) and HTLV-I-associated myelopathy (or tropical spastic paraparesis) (HAM/TSP). Previous models have been successful in providing insight into the progression of HTLV-I infection. The relative simplicity of HTLV as well as its similarities to HIV and other diseases allow HTLV-I research to have diverse applications. The development of HAM/TSP is precipitated by a CTL immune response. Previous models for CTL response to HTLV-I infection have had relatively simple behaviours. A novel sigmoidal CTL response function results in complex behaviours previously unobserved. We establish the existence of bistability between solutions corresponding to carrier and endemic states. In addition, both super- and sub-critical Hopf bifurcations as well as the resulting stable and unstable periodic solutions are observed. Analytical and numerical results are discussed, as well as the biological consequences of the aforementioned behaviours. / Applied Mathematics

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