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1.
J Gen Virol ; 94(Pt 5): 1058-1068, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23288423

RESUMO

Triatoma virus (TrV) is a member of the insect virus family Dicistroviridae and consists of a small, non-enveloped capsid that encloses its positive-sense ssRNA genome. Using cryo-transmission electron microscopy and three-dimensional reconstruction techniques combined with fitting of the available crystallographic models, this study analysed the capsids corresponding to mature and several RNA-empty TrV particles. After genome release, the resulting reconstruction of the empty capsids displayed no prominent conformational changes with respect to the full virion capsid. The results showed that RNA delivery led to empty capsids with an apparent overall intact protein shell and suggested that, in a subsequent step, empty capsids disassemble into small symmetrical particles. Contrary to what is observed upon genome release in mammalian picornaviruses, the empty TrV capsid maintained a protein shell thickness and size identical to that in full virions.


Assuntos
Capsídeo/metabolismo , Microscopia Crioeletrônica/métodos , Dicistroviridae/ultraestrutura , Genoma Viral/genética , Triatoma/virologia , Vírion/ultraestrutura , Animais , Cristalografia , Dicistroviridae/isolamento & purificação , Dicistroviridae/fisiologia , Concentração de Íons de Hidrogênio , Imageamento Tridimensional , Insetos Vetores/virologia , Microscopia Eletrônica de Transmissão/métodos , Modelos Moleculares , Estabilidade Proteica , RNA Viral/genética , Montagem de Vírus
2.
J Clin Periodontol ; 21(8): 533-9, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7989616

RESUMO

Previous studies have indicated that oxygen-free radicals may cause damage to the periodontal tissues. This study compared the luminol-dependent chemiluminescence response (after stimulation with either opsonized zymosan or phorbol myristate acetate (PMA) of peripheral blood polymorphonuclear leukocytes (PMN) isolated from human subjects with a healthy periodontium (n = 7), gingivitis (n = 8), adult periodontitis (n = 8), or early-onset periodontitis (n = 17). These results were also compared with those obtained in a larger reference group which consists of 50 subjects without infection or inflammation, selected on the basis of laboratory investigations. An enhanced response was defined as being 2 standard deviations above the reference group mean; a reduced response was defined as being 2 standard deviations below this mean. Although PMN from patients with either gingivitis or periodontitis were often functionally activated (when compared to the PMN from the reference group), no significant differences could be found between the 4 groups, with regard to the chemiluminescence response means obtained in a basal state or after stimulation.


Assuntos
Periodontite Agressiva/metabolismo , Neutrófilos/metabolismo , Periodontite/metabolismo , Adulto , Idade de Início , Periodontite Agressiva/patologia , Células Cultivadas , Radicais Livres/metabolismo , Gengivite/metabolismo , Gengivite/patologia , Humanos , Medições Luminescentes , Luminol/farmacologia , Neutrófilos/efeitos dos fármacos , Periodontite/patologia , Periodonto/metabolismo , Periodonto/patologia , Espécies Reativas de Oxigênio/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Zimosan/farmacologia
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