RESUMO
The insecticide effect of a lectin obtained from Ricinus communis (castor-oil plant) on a population of houseflies from San José de Las Lajas was evaluated. Assays were performed with adults and larvae. Mortality was higher as the time f exposure to the extract increased DL50 was of 353.4 p.p.m. after 72 hours of exposure. It was observed a remarkedly significant reduction of the pupal development in the presence of the extract, which shows its insecticide activity.
Assuntos
Moscas Domésticas , Inseticidas , Plantas , Ricina , Animais , Cuba , Relação Dose-Resposta a Droga , Inseticidas/isolamento & purificação , Dose Letal Mediana , Pupa , Ricina/isolamento & purificação , Fatores de TempoRESUMO
Dialysable Leucocyte Extract (DLE) is a low molecular weight dialysable material of disrupted peripheral human leucocytes with widespread effects on the immune system. We described the in vitro anti-HIV activity of DLE as well as its three chromatographic fractions (Fa, Fb and Fc). To determine the levels of inhibition on HIV replication by DLE we infected MT-4 cell cultures, using the Bru viral isolate at 0.05, 0.1, 0.5 and 1 m.o.i. Previously, MT-4 cells cultures were treated with DLE or fractions at non-toxic concentrations. Reverse transcriptase (RT) activity and p24 antigen were evaluated in culture supernatants at seven days postinfection. No effect was observed when MT-4 cells were incubated with DLE for 3 h. Whereas inhibition of HIV production was observed when MT-4 cells were pre-treated for a longer period of time. DLE inhibited p24 production and RT activity more than 50% at 0.1 m.o.i. More than 80% of inhibition was observed for all doses of DLE tested at 0.05 m.o.i. Higher viral doses (m.o.i. 0.5 and 1) were used to assess the antiviral activity of DLE fractions. Fraction Fb inhibits viral production more than 80%. Otherwise, fractions Fa and Fc did not show inhibitory effect for any viral dose used. These results indicate that DLE is able to modulate cell susceptibility to viral infection in vitro.
Assuntos
Fármacos Anti-HIV/farmacologia , Extratos Celulares/farmacologia , Infecções por HIV/tratamento farmacológico , Leucócitos/química , Leucócitos/imunologia , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/virologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Diálise , Infecções por HIV/imunologia , HIV-1/efeitos dos fármacos , HIV-1/fisiologia , Humanos , Replicação Viral/efeitos dos fármacosRESUMO
Ten Cryptococcus neoformans strains of human origin were studied in order to know their variety by using 2 different culture mediums: creatinine-bromothymol-blue-dextrose and glycine-cycloheximide-phenol red. The results obtained in the two mediums were not totally coincidental. The possible causes and the specificity of these mediums for identifying C. neoformans varieties are discussed.