690 research outputs found

    Comparação microscópica e proliferativa de fibroblastos gengivais de pacientes com gengiva normal e com fibromatose gengival hereditária

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    Hereditary gingival fibromatosis (HGF) is a rare oral condition, clinically manifested through a generalized and fibrotic enlargement of the gingiva, which may present as an isolated clinical finding or in association with other features, as part of a syndrome. The biological mechanisms involved in HGF are unknown, and the results of cell-culture studies are controversial. To elucidate the phenotypic and proliferative characteristics of HGF fibroblasts, we isolated 4 cell lines of gingival fibroblasts from members of the same family with HGF, and compared with gingival fibroblasts from 4 healthy patients (NG). HGF and NG fibroblasts, in subconfluent culture densities, showed typical morphological characteristics, such as spindle form with a central spherical nucleus and long cytoplasmatic prolongations, but in saturation density, HGF cells were shorter than control cells. The nucleus/cytoplasm relation was always smaller in all HGF cell lines, suggesting that the cellular reduction is derived from reduction or compaction of the cytoplasm and not of the nucleus. The proliferation rate was higher in fibroblasts from HGF than in the ones from NG. These results suggest that differences in the morphology and proliferation of HGF fibroblasts may be associated with the biological events involved in the pathogenesis of gingival overgrowth in HGF patients.Fibromatose gengival hereditária (FGH) é uma condição bucal rara clinicamente manifestada por um aumento gengival generalizado e fibrótico, podendo apresentar-se de forma isolada ou associada a outras alterações, como parte de síndromes. Os mecanismos biológicos envolvidos na FGH são desconhecidos, e os resultados de estudos de cultura celulares são controversos. Para elucidar as características fenotípicas dos fibroblastos de FGH, nós isolamos quatro linhagens celulares de fibroblastos de FGH de indivíduos de uma mesma família e comparamos as características morfológicas e proliferativas com fibroblastos provenientes de pacientes com gengiva clinicamente normal (GN). Fibroblastos de GN e FGH em condições de subconfluência celular apresentaram típicas características morfológicas, como formato fusiforme, núcleo central e longos prolongamentos citoplasmáticos, mas em condições de saturação da densidade celular, os fibroblastos de FGH apresentaram dimensões menores que as células controle. A relação núcleo/citoplasma foi sempre menor para todas as linhagens celulares de fibroblastos de FGH, sugerindo que a redução celular, é proveniente de uma redução ou compactação citoplasmática e não nuclear. A capacidade proliferativa de fibroblastos de FGH foi maior que a de fibroblastos de GN. Estes resultados sugerem que diferenças morfológicas e proliferativas dos fibroblastos de FGH podem estar associadas aos eventos biológicos envolvidos na etiopatogenia do aumento gengival observado em pacientes com FGH

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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