Formation of 5,16-androstadien-3 beta-ol from pregnenolone in human testicular microsomes

A microsomal fraction of testicular tissue from a patient with prostatic carcinoma was incubated with [4-14C]pregnenolone in the presence of an NADPH-generating system for different periods of time. The metabolites were separated by Sephadex LH-20 column chromatography and then identified by thin-layer chromatography, radio-gas chromatography, and crystallization studies. Pregnenolone was converted to a major metabolite, 5-androstene-3 beta,17 beta-diol via 17-hydroxypregnenolone and then dehydroepiandrosterone. Another major metabolite was 5,16-androstadien-3 beta-ol, which increased with the time of incubation and accumulated in the incubation medium. After 120 min of incubation, 34.6% of the precursor was converted to 5-androstene-3 beta,17 beta-diol and 15.1% to 5,16-androstadien-3 beta-ol. In addition to the above-mentioned steroids, 16 alpha-hydroxypregnenolone, 5-pregnene-3 beta,20 alpha-diol, and 5-androstene-3 beta,17 alpha-diol were identified as minor metabolites of pregnenolone. From these results it was concluded that human testicular microsomes possess enzymic activities for the synthesis of 5,16-androstadien-3 beta-ol, as well as androgens from pregnenolone.     

Pleiotropic Alteration of Activities of Several Toxins and Enzymes in Mutants of Staphylococcus aureus

Pleiotropic alteration of several genetic characters including toxin production was quantitatively shown with a strain of Staphylococcus aureus of phage type 80, 81 which had been given a very specific genetic marker (temperature sensitivity of mannitol fermentation) to avoid confusion by contamination. Thus, alpha-hemolysin hyperproducers obtained by N-methyl-N'-nitro-N-nitrosoguanidine (NTG) mutagenesis were very often hyperproducers of DNase, coagulase, and protease. Their colonies were less yellow than the parent. DNase hyperproducers obtained after NTG mutagenesis were also often hyperproducers of alpha-hemolysin, coagulase, and protease, with colonies less yellow than the parent. Almost all of the revertants obtained by mutagenesis with ethyl methane sulfonate with respect to alpha-hemolysin or DNase were shown to have simultaneously become hypoproducers of alpha-hemolysin, DNase, and protease. Since the pleiotropic alteration of multiple functions was thus quantitatively confirmed, the mechanism underlying this phenomenon should probably be related to a regulatory mechanism common to them.     

Variation in virulence of Coxsackie virus B3 in the hearts of mice. I. Comparison of mortality and virus growth in the heart and other organs

Virulence of Coxsackie virus B3 (CB3) was compared in mice between strain SK-74 isolated from a patient and strain T-70 isolated from a healthy child as well as between prototype strain Nancy and its mouse-passaged derivative strain PMH. Strain SK-74 showed a high mortality (40-80%), while strain T-70 did not induce deaths in mice (mortality: 0%). Strain PMH showed a high mortality (65-85%), but strain Nancy did not cause deaths in the mice. In agreement with the mortality trend, virus titers in the heart and other organs of mice inoculated with strain SK-74 and PMH were higher than those in mice inoculated with T-70 and Nancy strains. Since virus titers in the heart remained higher than those in other organs, the heart was regarded as the main organ in which CB3 could replicate and induce cell degeneration. The present results suggest that a marked variation in virulence in the hearts of mice among CB3 strains occurred and that passage through the hearts of mice enhances the virulence of CB3 in the hearts of mice.     

Variation in virulence of Coxsackie virus B3 in the heart of mice, II. Pathological comparison

Histopathological analysis of the heart in adult mice inoculated with Coxsackie virus B3 (CB3) strains revealed that strain SK-74 isolated from a patient suffering from severe diarrhea and fever produced severe myocarditis but strain T-70 isolated from a healthy child induced no lesion in the hearts of mice tested, and that intensities of myocardial lesions in mice inoculated with strain PMH were higher than those in mice inoculated with prototype strain Nancy. The results support the conclusion in the preceding paper that strain SK-74 is virulent but strain T-70 is avirulent in mice. The results also partially indicated that the virulence of prototype strain Nancy in the heart of mice is enhanced by passages of the strain in the heart of mice. All four strains of CB3 produced lesions in the pancreas although lesions induced by strain T-70 were less marked than those induced by the remaining three strains.     

Enzymatic separation of hardly separable mixtures of structural isomers

Lipase-meditated separation of six hardly separable mixtures of structural isomers was carried out. It has become apparent that the hydrolysis rate of the C(5)-acetoxyl group of methyl (±)-5-acetoxy-4-aryl-(2E)-pentenoate possessing the ortho-substituents in the aromatic ring was slower than that of the corresponding compound with no substituents at the ortho-position. The hydrolysis rate of the C(5)-acetoxyl group of methyl (±)-5-acetoxy-2-aryl-(3E)-pentenoate possessing a remote reaction site from the ortho-substituents in the aromatic ring was proved to be faster than that of methyl (±)-5-acetoxy-4-aryl-(2E)-pentenoate.     

Rapid identification of specific genes in E. coli by hybridization to membranes containing the ordered set of phage clones

A simplified protocol for the hybridization of labeled oligonucleotides and other radiolabeled DNAs to membranes is described and used for the detection of specific recombinant phage in the ordered miniset collection representing virtually the entire E. coli genome.