RESUMO
HIV-1 Gag protein assembles at the plasma membrane of infected cells for viral particle formation. Gag targets lipids, mainly PI(4,5)P2, at the inner leaflet of this membrane. Here, we address the question whether Gag is able to trap specifically PI(4,5)P2 or other lipids during HIV-1 assembly in the host CD4+ T lymphocytes. Lipid dynamics within and away from HIV-1 assembly sites were determined using super-resolution microscopy coupled with scanning fluorescence correlation spectroscopy in living cells. Analysis of HIV-1-infected cells revealed that, upon assembly, HIV-1 is able to specifically trap PI(4,5)P2 and cholesterol, but not phosphatidylethanolamine or sphingomyelin. Furthermore, our data showed that Gag is the main driving force to restrict the mobility of PI(4,5)P2 and cholesterol at the cell plasma membrane. This is the first direct evidence highlighting that HIV-1 creates its own specific lipid environment by selectively recruiting PI(4,5)P2 and cholesterol as a membrane nanoplatform for virus assembly.
Assuntos
Colesterol/metabolismo , HIV-1/fisiologia , Nanopartículas/química , Fosfatidilinositol 4,5-Difosfato/metabolismo , Montagem de Vírus , Produtos do Gene gag do Vírus da Imunodeficiência Humana/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Sobrevivência Celular , Difusão , Humanos , Células Jurkat , Esfingomielinas/metabolismo , Vírion/metabolismoRESUMO
BACKGROUND: SynB family peptides conjugated to several drugs have been shown to increase the brain uptake and in vivo activities of these drugs via an adsorptive-mediated transcytosis mechanism. Based on both in vivo and in vitro experimental data, a cell uptake component has been added to our computational model of blood-brain barrier. METHODS: In situ brain perfusion, in vitro cell model and a computational cell uptake model have been used to discover brain-penetrating properties of SynB peptides and to screen libraries of new rationally designed peptide vectors suitable for brain drug delivery. RESULTS AND CONCLUSION: Starting from small peptide vectors that enhance the brain transport coefficient, the BBB platform has made it possible to design libraries of peptide vectors with enhanced transport properties.
Assuntos
Barreira Hematoencefálica/metabolismo , Fármacos do Sistema Nervoso Central/farmacocinética , Sistema Nervoso Central/metabolismo , Portadores de Fármacos/farmacocinética , Modelos Biológicos , Oligopeptídeos/farmacocinética , Sequência de Aminoácidos , Animais , Transporte Biológico , Portadores de Fármacos/química , Avaliação Pré-Clínica de Medicamentos , Humanos , Dados de Sequência Molecular , Oligopeptídeos/química , Biblioteca de Peptídeos , Prognóstico , RatosRESUMO
Hematologic and serum biochemical values were determined in blood samples from 217 donkeys (Equus asinus). Donkeys were classified on the basis of size, sex, age, and whether they were domestic or feral. Parametric (mean +/- 2 SD) and nonparametric (2.5th to 97.5th percentile) reference ranges were calculated for each analyte. For all donkeys, 26 of 46 analytes significantly departed from gaussian distribution. Serum lactate dehydrogenase activity in miniature donkeys was higher than that in other donkeys. Differential leukocyte counts in feral donkeys differed from those in other types in ways that suggested that the former had smaller parasite loads or experienced greater stress. Erythrocyte, lymphocyte, and platelet counts and fibrinogen, glucose, inorganic phosphorus, and potassium concentrations decreased with age. Eosinophil counts, mean corpuscular volume, and plasma protein, serum protein, and serum globulin concentrations increased with age. Female donkeys had significantly (P less than 0.05) higher mean corpuscular hemoglobin concentration and leukocyte and neutrophil counts than did male donkeys. Mean corpuscular hemoglobin increased with age, and females had higher values than did males of all age groups. An interaction between age and sex was observed for alkaline phosphatase activity, with a trend for decreased activity with age.
Assuntos
Animais Domésticos/sangue , Animais Selvagens/sangue , Constituição Corporal , Perissodáctilos/sangue , Fatores Etários , Animais , Contagem de Células Sanguíneas/veterinária , Feminino , Masculino , Valores de Referência , Fatores SexuaisRESUMO
Con el objeto de evaluar clínica y espirométricamente la eficacia y seguridad de clenbuterol comparativamente con terbutalina y placebo, se estudiaron 30 pacientes pediátricos divididos en tres grupos de 10 pacientes cada uno. Se diseñó un estudio simple siego con grupo control (placebo), aleatorio, prospectivo y obsevacional. La edad promedio de los tres grupos fue de 8.2 años, el peso de 29 Kg y la talla 130 cm; 19 pacientes gueron masculinos y 11 femeninos. El grupo I recibió clenbuterol solución, en dosis de 0.0012 mg/Kg día en dos tomas por siete días; el grupo II recibió terbutalina en dosis de 0.075 mg/Kg día en tres tomas por el mismo tiempo y el grupo III recibió placebo. Se observaron diferencias estadisticamente significativas en favor del grupo tratado con clenbuterol en FEV1 PMF y CV. Los efectos colaterales fueron sin importancia
