RESUMEN
The authors have obtained several variants of liposomal forms of human alpha 2-interferon. The forms intended to preserve antiviral activity with regard to the methods of liposomal formation were comparatively studied. It has been found that liposomal formation through stirring caused no decrease in antiviral activity.
Asunto(s)
Interferón Tipo I/administración & dosificación , Efecto Citopatogénico Viral , Portadores de Fármacos , Humanos , Interferón Tipo I/farmacología , Interferón alfa-2 , Interferón-alfa , Liposomas , Métodos , Proteínas Recombinantes , Virus de la Estomatitis Vesicular Indiana/efectos de los fármacosRESUMEN
The technique is described for obtaining pH-sensitive biotinylated liposomes. The liposomes included phosphatidyl ethanolamine, oleic acid, cholesterol, biotin amidocaproyl phosphatidyl ethanolamine, with a molar ratio of 7:3:3:0.1 or 4:2:4:0.1. The fluorescein stain calcein at ++self-limited concentration, 32-P-dTTP, or DNA was incorporated into the internal liposome medium. The liposomes were stable in neutral or mildly alkaline medium but became leaky and showed agglutination at pH 5.7. Liposomes were agglutinated in the presence of avidin and bound specifically to the layer of avidin on the surface of immunological plates. The apparent liposome affinity to the avidin layer was up to 10(-11) M. The avidin-biotin system allows for specific binding of liposomes to human lymphocytes via biotinylated anti-CD5-antibodies. A simple, convenient, and rapid procedure has been elaborated for the binding of water-soluble substances (plasmid DNA included) to liposomes without DNA destruction.
Asunto(s)
Avidina/farmacología , Biotecnología/métodos , Biotina/farmacología , ADN/administración & dosificación , Liposomas/administración & dosificación , Linfocitos/efectos de los fármacos , Fosfatidiletanolaminas/farmacología , Plásmidos , Sitios de Unión , ADN/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Técnicas In Vitro , Linfocitos/metabolismoRESUMEN
In electrophysiological experiments with a preparation of the isolated Helix pomatia brain, a study was made of the effect of pulsed irradiation with high-energy electrons (20 MeV) on membrane potentials and pulse activity of "silent", pacemaking and postsynaptic neurons. It was shown that after irradiation with 150 and 300 Gy (dose rate 5 Gy/s and pulse frequency 50 Hz) "silent" neurons retain their excitability. Pacemaking neurons responded to radiation by a drastic increase in spontaneous pulse activity followed by its transfer to a clipped then to an irregular one. At the same time, the discharge frequency increased in the postsynaptic neurons.
Asunto(s)
Encéfalo/efectos de la radiación , Electrones , Neuronas/efectos de la radiación , Animales , Caracoles Helix , Técnicas In Vitro , Potenciales de la Membrana/efectos de la radiación , Conducción Nerviosa/efectos de la radiación , Neuronas/fisiologíaRESUMEN
Acylation of protein amino groups by N'-hydroxysuccinimide ester of N-succinyl phosphatidylethanolamine in reverse micelles of diisooctylsulphosuccinate in hexane was studied. The experiment in a model system (glycine solution in reverse micelles) showed rate of acylation of amino groups to be by over an order of magnitude higher than rate of hydrolysis. Water-soluble proteins (alpha-chymotrypsin and IgG), modified by means of this method, can effectively bind liposomes without disturbing the integrity of liposomal membrane.