RESUMO
An extensive survey was performed from 2002 to 2006 to detect and identify phytoplasmas associated with Chilean grapevines. Nested polymerase chain reaction assays using phytoplasma universal primer pairs P1/P7 and R16F2n/R2 detected phytoplasmas in 34 out of the 94 samples tested (36%). Restriction fragment length polymorphism (RFLP) analyses, cloning, and sequencing allowed identification of phytoplasmas belonging to ribosomal subgroups 16SrI-B, 16SrI-C, 16SrVII-A, and 16SrXII-A. The 16SrVII-A phytoplasma represents a new finding in grapevine; moreover, variability of the RFLP profile was observed in some of the 16SrXII-A phytoplasmas, indicating possible new ribosomal subgroups. Mixed phytoplasma infections and infections of phytoplasmas together with one or more viruses also occurred.
RESUMO
Bone marrow contains a population of mesenchymal stem cells with the ability to differentiate into cells that form bone, cartilage, adipose, and other connective tissues. Stem cells can be isolated from bone marrow aspirates and expanded in vitro. Presently, most stem cells studies have been performed in cells obtained from "healthy" control subjects. The goal of this study was to compare the functional characteristics of mesenchymal stem cells derived from "healthy" control and osteoporotic postmenopausal women to better understand the mechanisms involved in the pathogenesis of this disease. Osteoporotic and control stem cells have similar morphology and size and express similar cell surface antigens as evidenced by their reactivity with cell specific monoclonal antibodies. Mesenchymal stem cells from osteoporotic women differ from controls in having a lower growth rate than control cells, being refractory to the mitogenic effect of IGF-1, and exhibiting a deficient ability to differentiate into the osteogenic linage as evidenced by the alkaline phosphatase activity and calcium phosphate deposition. We conclude that in osteoporosis stem cell growth, proliferative response and osteogenic differentiation are significantly affected. Also, the study of mesenchymal stem cells from osteoporotic postmenopausal women may provide a better understanding of the mechanisms involved in the pathogenesis of the osteoporosis. It may also serve to test in vitro in rapid manner novel new therapeutic strategies.
Assuntos
Células-Tronco Hematopoéticas/patologia , Osteogênese , Osteoporose/patologia , Idoso , Fosfatase Alcalina/metabolismo , Estudos de Casos e Controles , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Feminino , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/enzimologia , Humanos , Técnicas In Vitro , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like I/farmacologia , Osteogênese/efeitos dos fármacos , Osteogênese/fisiologia , Osteoporose/enzimologiaRESUMO
The human androgen receptor is a member of the superfamily of steroid hormone receptors and contains three functional domains: an amino-terminal region involved in the expression of androgen regulated genes, a central cysteine-rich DNA binding region and a carboxy-terminal hormone binding region. Proper functioning of this protein is a prerequisite for normal male sexual differentiation and development. Androgen action is currently studied in vitro, using fibroblasts culture from genital skin and complementary DNA of the androgen receptor gene has been recently cloned and sequenced. During recent years a substantial progress has been made elucidating the structure-function relationship of the androgen receptor and the characterization of the molecular defects associated with androgen insensitivity syndromes. There appears to be a broad correlation between the degree of receptor dysfunction caused by the mutation and the patient phenotype.
Assuntos
Genes , Estrutura Terciária de Proteína , Receptores Androgênicos/genética , Humanos , Masculino , Receptores Androgênicos/fisiologiaAssuntos
Estradiol/farmacologia , Células Intersticiais do Testículo/metabolismo , Testosterona/biossíntese , Animais , Fenômenos Químicos , Química , Técnicas In Vitro , Células Intersticiais do Testículo/efeitos dos fármacos , Hormônio Luteinizante/farmacologia , Masculino , Ratos , Esteroides/metabolismo , Testículo/fisiologiaRESUMO
Studied were morphologically the organs of 10 cattle originating from two provinces of Cuba that suddenly succumbed ( muerte subita ). There were hemorrahagic diathesis, and histologically--general activation of the reticulo-endothelial system, nonsuppurative encephalomyocarditis, interstitial nonsuppurative hepatitis, nephritis, and pneumonia as well as catarrhal hemorrhagic gastroenteritis. In all cases there were among the lymphoid proliferations diffusely disseminated eosinophile leukocytes ( hyperergia ). This finding showed that the disease had run a subacute or chronic course which was made acute by the action of some stress factors (continuous running, intoxications oligoelement disturbances, etc.). The finding was also characteristic of reactive processes taking place under the action of some specific virus that probably took part in the etiology of the disease and required an intermediary host that remained unknown at the time.