RESUMEN
We examined the diurnal variations and the effects of 48-hour fasting on hematological and serum biochemical values to obtain basic physiological data on ten male and seven female Göttingen minipigs 6 to 16 months of age. For all hematological parameters examined (RBC, HCT, HGB, WBC and PLT), there was no diurnal variation in either sex, but red blood cell parameters were affected by fasting, with an increase in males and a decrease in females. Three serum biochemical parameters (GOT, UN and i.p.) for males and four (GOT, UN, Ca and i.p.) for females exhibited diurnal variation. These variations were eliminated by fasting. The BIL level in males was increased by fasting, and the color of serum was yellowish. Fe concentration in both sexes and CRE and Mg levels in males were decreased by fasting. These findings are basic data for various experiments on minipigs, and indicate that great care is required in establishing feeding times and fasting intervals and in the analysis of results of experiments on minipigs.
Asunto(s)
Células Sanguíneas/fisiología , Ritmo Circadiano/fisiología , Ayuno/fisiología , Porcinos Enanos/fisiología , Animales , Recuento de Células Sanguíneas , Análisis Químico de la Sangre , Femenino , Masculino , PorcinosRESUMEN
A novel inhibitor of topoisomerases designated as topostatin was isolated from the culture filtrate of Thermomonospora alba strain No. 1520. The inhibitory activity of topostatin was shown to be pH- and temperature-dependent with a maximum around at pH 6 and 28 degrees C. The stability of topostatin decreased with decreasing pH and rising temperature. Topostatin inhibited topoisomerases I and II in a competitive manner with respect to DNA. The inhibitor also inhibited some restriction endonucleases such as Sca I, Hind III and Pst I, but not Alu I, Bam HI, Eco RI, RNase A, DNase I, DNase II and DNA ligase. Topostatin did not induce the nuclear accumulation of p53 protein by DNA damage in the normal human cells.
Asunto(s)
Lactamas/farmacología , Inhibidores de Topoisomerasa I , Inhibidores de Topoisomerasa II , Núcleo Celular/metabolismo , Desoxirribonucleasas de Localización Especificada Tipo II/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Fibroblastos , Humanos , Concentración de Iones de Hidrógeno , Temperatura , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
A novel inhibitor of topoisomerases designated as topostatin was isolated from the culture filtrate of Thermomonospora alba strain No. 1520. Topostatin inhibited the relaxation of supercoiled pBR322 DNA by calf thymus topoisomerase I, and also inhibited the relaxation of supercoiled pBR322 DNA and decatenation of kinetoplast DNA by human placenta topoisomerase II. Topostatin had neither ability to stabilize the cleavable complex nor ability to intercalate into DNA strands. The inhibitor exhibited growth inhibitory activity against the tumor cells (SNB-75 and SNB-78) of central nervous system, but did not exhibit any antimicrobial activity against Gram-positive and Gram-negative bacteria, yeasts and fungi.
