An Improved Enrichment Broth for Isolation of Escherichia coli O157, with Specific Reference to Starved Cells, from Radish Sprouts

An enrichment broth was developed for the efficient isolation of Escherichia coli O157 from radish sprouts. The broth was buffered peptone water containing 0.5% sodium thioglycolate (STG-BPW), which was designed to allow growth of E. coli O157 in starved and unstarved states. However, this medium suppressed the growth of non-carbohydrate-fermenting obligate aerobes whose colonial appearance on sorbitol MacConkey agar containing cefixime and tellurite (CT-SMAC) resembled that of E. coli O157. Both starved and unstarved cells of E. coli O157 experimentally inoculated into radish sprouts were successfully recovered with STG-BPW enrichment in all cases, most of which showed marked disappearance of E. coli O157-like colonies on CT-SMAC.     

Effect of triethylenepentaminehexaacetic acid on the renal damage in cadmium-treated Syrian hamsters

Cadmium (Cd)-induced nephropathy was treated by triethylene-pentaminehexaacetic acid (TTHA) in male Syrian hamsters. Hamsters injected three times a week with 3 mg/kg body wt CdCl₂ showed proteinuria, urinaryN-acetyl-β-d-inglucosaminidase (NAG), and fractional excretion of sodium (FENa) when compared to saline-injected control. Cd-treated hamsters injected ip with TTHA 10 mg/kg body wt five times a week showed reduction of renal damage, including reductions in urinary protein (from 6.7±2.2 to 4.3±0.5 mg/d) and NAG (0.17±0.06 to 0.04±0.02 U/d). Urinary excretion of Cd was significantly increased (from 87±51.3 to 3052±1485 mg/L) by TTHA administration. Cd concentration in renal cortical tissue was slightly reduced (26.4±3.0 to 21.8±2.7 mg/g. protein). Excretion of malondialdehyde (MDA) was increased only in Cd-injected hamsters (to 2.1±1.6 nM/L), and elevated MDA in renal cortical tissue was not reduced by the administration of TTHA (1041±105 vs 1104±358 nM/g protein). Glutathione (GSH) concentration in the renal cortex was significantly elevated after Cd administration and further increased after TTHA administration (5.5±2.1 to 9.8±2.0 μg/50 mg protein). There were no marked effects on creatinine clearance (Ccr) and hematocrit. Moreover, renal morphological changes were improved significantly by treatment with TTHA. We demonstrated the efficacy of TTHA in the treatment of Cd-induced nephropathy in hamsters. Although the precise mechanism of the TTHA effects on Cd-induced nephropathy has not been elucidated, it might involve GSH reducing the elevated MDA concentration in renal tissue.     

Differential Localization of the γ3 and γ12 Subunits of G Proteins in the Mammalian Brain

Abstract: The localization of two forms of the γ subunit of G proteins, γ₃ and γ₁₂, was examined in the mammalian brain. Concentrations of these two γ subunits increased markedly, as did those of glial fibrillary acidic protein, during postnatal development in the rat cerebral cortex. In aged human brains, by contrast, the concentration of γ₃ tended to decrease with age, whereas that of γ₁₂ in the temporal cortex increased slightly. An immunohistochemical study of human brains revealed that γ₃ was abundant in the neuropil, whereas γ₁₂ was localized in glial cells. In the hippocampal formation of aged human brains, levels of γ₁₂-positive cells, as well as levels of glial fibrillary acidic protein- and vimentin-positive astrocytes, increased, in particular in the CA1 subfield and the prosubiculum, in which there was a decrease in the number of pyramidal cells. The appearance of γ₁₂-positive cells associated with the loss of pyramidal cells was also observed in the hippocampus of rats that had been treated with kainic acid. These results indicate that γ₁₂ is strongly expressed in reactive astrocytes. In a study of cultured neural cells, we found that γ₁₂ was predominant in glioma cells, such as C6 and GA-1 cells, in contrast with the specific localization of γ₃ in PC12 pheochromocytoma cells, which are neuron-like cells. Taken together, the results indicate that γ₃ and γ₁₂ are selectively expressed in neuronal and glial cells, respectively, and that concentrations of γ₃ and γ₁₂ in the brain are related to the numbers and/or extent of maturation of these cells.     

Phylogeny of symbiotic methanogens in the gut of the termite Reticulitermes speratus

Abstract The phylogeny of a symbiotic methanogen inhabiting the gut of a lower termite, Reticulitermes speratus , was analysed without cultivation. The small subunit ribosomal RNA gene (ssrDNA) and a 640-bp portion of the gene encoding subunit A of methyl coenzyme M reductase ( mcrA ) were amplified from a mixed-population DNA of the termite gut by polymerase chain reaction and cloned. The nucleotide sequence of the ssrDNA and the predicted amino acid sequence of the mcrA product were compared with those of the known methanogens. Both comparisons indicated that the termite symbiotic methanogen belonged to the order Methanobacteriales but was distinct from the known members of this order.     

Clinical application of a live varicella vaccine (Oka strain) in a hospital

A total of 239 children, including 22 high-risk children and 55 non-high risk diseased children have been immunized with a live varicella vaccine (Oka strain) since June, 1978. No clinical reaction attributable to the vaccine has been observed. Of these children, 87 received emergency vaccination. Of 47 children receiving emergency vaccination because they had been in contact with varicella patients either in hospital, school or a playground, only 5 developed varicella and their symptoms were mild. Of 40 children receiving emergency vaccination because of exposure to varicella in their home, 10 developed mild varicella and 30 were protected. Clinical symptoms of varicella when seen seemed to be due to incomplete protection because the vaccine was given too late rather than to clinical reactions to the vaccine. During follow-up period of 6 to 66 months after vaccination, 8 children showed very mild rashes without fever as the result of exogenous varicella infection.     

A retarded rate of DNA replication and normal level of DNA repair in Werner's syndrome fibroblasts in culture

We investigated the cloning efficiency, DNA repair, and the rate of DNA replication in the skin fibroblasts from patients with Werner's syndrome (WS) of an autosomal recessive premature aging disease. Five WS strains exhibited normal levels of sensitivity toward X-ray and UV killings and repair of X-ray induced single strand breaks of DNA (rejoining) and UV damage to DNA (unscheduled DNA synthesis). The sedimentation of newly synthesizing DNA in alkaline sucrose gradients demonstrated a characteristic feature that only the elongation rate of DNA chains, estimated by the molecular weight increase, was significantly slower during early passages in WS cells than in normal Hayflick Phase II fibroblasts. In addition, plating efficiencies as well as the replicative potentials of five WS strains were more limited than those of normal cells under the identical culture conditions. It seems therefore that at least in the WS cells tested, the slow rate of DNA replication may be more related to the shortened lifespan and enhanced cell death, as manifestation of premature senescence at the cellular level, than be the DNA repair ability.     

Evolution of ribosomal proteins in Enterobacteriaceae.

The evolution of ribosomal proteins of about 70 bacterial strains belonging to the family Enterobacteriaceae has been studied by use of previously reported data (S. Osawa, T. Itoh, and E. Otaka, J. Bacteriol. 107:168-178, 1971) and those obtained in this paper. The proximity of the bacteria was quantified by co-chromatographing the differentially labeled ribosomal proteins from two strains on a column of carboxymethyl cellulose in various combinations. The were then classified into 12 groups (=species?) according to their ribosomal protein compositions and were placed in a phylogenic tree.     

Improved synthesis of 16alpha-hydroxylated androgens: intermediates of estriol formation in pregnancy.

16alpha-Hydroxyandrostenedione (16alpha-hydroxyandrost-4-ene-3,17-dione), 16alpha-hydroxytestosterone (16alpha,17beta-dihydroxyandrost-4-en-3-one) and 16alpha-hydroxydehydroepiandrosterone 3-sulfate (3beta, 16alpha-dihydroxyandrost-5-en-17-one 3-monosulfate) were synthesized by a new chemical approach with much improved yield. 16alpha-Bromoandrostendione was converted to the hydrazone of 16alpha-hydroxyandrostenedione which gave 16alpha-hydroxyandrostenedione on acid hydrolysis in total 63% yield. Oxidation of 16alpha-hydroxydehydroepiandrosterone with Jones' reagent also selectively afforded 16alpha-hydroxyandrostenedione. 16alpha-Hydroxytestosterone was observed by selective reduction of 16alpha-hydroxyandrostenedione with sodium borohydride. Reaction of 16alpha-hydroxydehydroepiandrosterone with chlorosulfonic acid in pyridine selectively gave the 3-monosulfate. The structure of the sulfate was deduced from its solvolysis to the starting material, and its acetylation and subsequent solvolysis to 16alpha-hydroxydehydroepiandrosterone 16-acetate. All procedures are suitable for large scale synthesis without the use of microorganisms.