Asunto(s)
Anomalías del Ojo , Enfermedades Hereditarias del Ojo , Enfermedades del Iris , Humanos , Segmento Anterior del Ojo/diagnóstico por imagen , Segmento Anterior del Ojo/anomalías , Anomalías del Ojo/complicaciones , Anomalías del Ojo/diagnóstico , Enfermedades Hereditarias del Ojo/complicaciones , Enfermedades Hereditarias del Ojo/diagnósticoRESUMEN
Nosiheptide (9671 R.P.) isolated from Streptomyces actuosus 40037 (NRRL 2954) is a sulfur-containing polypeptidic antibiotic, quite different from all the other members of this family. Very active in vitro against gram-positive bacteria, it is inactive in vivo in experimentally infected mice. Not toxic, even at high dose, it may be used as a feed additive for chickens and pigs and it shows a favourable effect on the growth and conversion index.
Asunto(s)
Antibacterianos , Streptomyces/análisis , Alimentación Animal , Animales , Bacterias/efectos de los fármacos , Pollos , Evaluación Preclínica de Medicamentos , Aditivos Alimentarios , Espectrometría de Fluorescencia , Espectrofotometría Infrarroja , Porcinos , Tiazoles/aislamiento & purificación , Tiazoles/farmacologíaAsunto(s)
Adyuvantes Inmunológicos/inmunología , Lipoproteínas/inmunología , Oligopéptidos/inmunología , Streptomyces/inmunología , Acetilmuramil-Alanil-Isoglutamina/inmunología , Animales , Formación de Anticuerpos , Cobayas , Hipersensibilidad Tardía , Ratones , Oligopéptidos/síntesis química , Ácidos Pimélicos/síntesis química , Ácidos Pimélicos/inmunologíaRESUMEN
From crude extracts of a Streptomyces strain exhibiting immunopotentiating effects, a tetrapeptide was isolated and its structure established as L Ala leads to D isoGlu leads to L, L Dap comes from Gly. This peptide was devoid of biological activity but its chemical coupling with lauric acid gave a substance endowed with adjuvant and immunostimulating properties. This substance and the corresponding synthetic lauroyltetrapeptide were as active in this respect as the muramyl-dipeptide, thus far considered as the minimal adjuvant-active structure of bacterial cell walls: the presence of a sugar moiety is therefore not a prerequisite for immunopotentiating activities.
Asunto(s)
Adyuvantes Inmunológicos , Glicopéptidos/inmunología , Streptomyces/inmunología , Animales , Formación de Anticuerpos , Ácidos Láuricos , Ratones/inmunología , Ácidos Murámicos , Oligopéptidos/aislamiento & purificación , Bazo/inmunologíaRESUMEN
Emericid is a new polyether polycyclic ionophore antibiotic excreted by Streptomyces hygroscopicus (DS 24 367). Active in vitro against Gram-positive bacteria, it is ineffective in vivo. At a 0.006-0.02% level in the diet it protects chickens and rabbits against coccidiosis.
Asunto(s)
Antibacterianos , Streptomyces/metabolismo , Animales , Antibacterianos/biosíntesis , Antibacterianos/uso terapéutico , Fenómenos Químicos , Química , Pollos , Éteres/biosíntesis , Ionóforos/biosíntesis , Pruebas de Sensibilidad Microbiana , ConejosRESUMEN
Mengo virus double-stranded ribonucleic acid (dsRNA) was obtained on a semi-industrial scale from infected cultures of BHK-21 cells grown in suspension. Yield of the extraction and purification operations was small (about 22 mg from 10(11) cells in a 100-liter culture). Physicochemical characterization of this dsRNA gave an estimated molecular weight close to 4 x 10(6), a density of 1.59 (similar to that of the poliovirus dsRNA), and a thermal transition midpoint of 94 C. This product was a little more toxic for the mouse, by the intravenous route, than polyriboinosinic . polyribocytidylic acid (poly I:C) and strictly comparable in this respect to poliovirus dsRNA. The interferon-inducing capacity in the mouse and the antiviral activities in the mouse (infected with encephalomyocarditis, Semliki Forest, influenza, foot-and-mouth disease, and murine hepatitis viruses) and in the rabbit (Shope fibroma virus) of the ultraviolet light-inactivated product were practically identical, on a quantitative basis, with those of poly I:C. In vitro and in vivo experiments showed the dsRNA from Mengo virus to be slightly but significantly more resistant than poly I:C to the inactivating effect of human serum.