Relationships between colony morphotypes and oil tolerance in Rhodococcus rhodochrous

A mucoidal strain of Rhodococcus rhodochrous was resistant to 10% (vol/vol) n-hexadecane, while its rough derivatives were sensitive. When the extracellular polysaccharide (EPS) produced by the mucoidal strain was added to cultures of the rough strains, the rough strains gained resistance to n-hexadecane. Thus, EPS confer tolerance to n-hexadecane in members of the genus Rhodococcus.     

Biting reduces acute stress-induced oxidative stress in the rat hypothalamus

We investigated the inhibitory effect of para-masticatory activity, namely biting, on restraint stress-induced oxidative stress. A blood brain barrier-permeable nitroxyl spin probe, 3-methoxycarbonyl-2,2,5,5,-tetramethylpyrrolidine-1-oxyl (MC-PROXYL), was administered to rats and L-band electron spin resonance (ESR) and ESR-computerized tomography (ESR-CT) imaging were used to show that the decay rate constant of MC-PROXYL in the hypothalamus of isolated brain after 30 min of restraint stress was more rapid than in unrestrained control rats, suggesting that restraint was associated with oxidative stress. Interestingly, biting during restraint stress caused the decay rate constant of MC-PROXYL in isolated brain to approach that of the control group. These observations suggest that biting suppresses oxidative stress induced by restraint stress, and that the anti-stress effect of masticatory motor activity movements, such as biting, are important for reducing the adverse effects associated with exposure to psychological stressors.     

ERVK9, transposons and the evolution of MHC class I duplicons within the alpha-block of the human and chimpanzee

The genomic sequences within the alpha-block (approximately 288-310 kb) of the human and chimpanzee MHC class I region contains ten MHC class I genes and three MIC gene fragments grouped together within alternating duplicated genomic segments or duplicons. In this study, the chimpanzee and human genomic sequences were analyzed in order to determine whether the remnants of the ERVK9 and other retrotransposon sequences are useful genomic markers for reconstructing the evolutionary history of the duplicated MHC gene families within the alpha-block. A variety of genes, pseudogenes, autologous DNA transposons and retrotransposons such as Alu and ERVK9 were used to categorize the ten duplicons into four distinct structural groups. The phylogenetic relationship of the ten duplicons was examined by using the neighbour joining method to analyze transposon sequence topologies of selected Alu members, LTR16B and Charlie9. On the basis of these structural groups and the phylogeny of the duplicated transposon sequences, a duplication model was reconstructed involving four multipartite tandem duplication steps to explain the organization and evolution of the ten duplicons within the alpha-block of the chimpanzee and human. The phylogenetic analysis and inferred duplication history suggests that the Patr/HLA-F was the first MHC class I gene to have been fixed and not required as a precursor for further duplication within the alpha-block of the ancestral species.     

Trichoblastoma of the skin occurring in the breast. A case report

BACKGROUND: Trichoblastoma is a rare benign skin appendage tumor constituted mostly of follicular germinative cells. It can arise on any part of the body except the palms, soles, nail units and mucosal membranes. No case of it in breast skin has been reported before. Furthermore, fine needle aspiration cytology findings on this lesion have not been described before. CASE: A 76-year-old female presented with a firm nodule in her left breast. The tumor was well demarcated, about 1.5 cm in diameter. Fine needle aspiration cytology revealed clusters composed of relatively uniform cells with a high nuclear/cytoplasmic ratio. In the midst of some clusters, the tumor cells had a more abundant cytoplasm. Fibrocellular interstitium or dense cyanophilic acellular material occasionally was attached to them. The tumor cells had oval or fusiform nuclei that had fine, evenly dispersed chromatin. To exclude a diagnosis of breast cancer, it is important to recognize that the clusters are composed of basaloid cells with focal squamous eddies and that there is at least focally peripheral palisading. The histopathologic diagnosis was trichoblastoma. CONCLUSION: Fine needle aspiration cytology can distinguish trichoblastoma from malignant diseases of the breast and may be used to diagnose the lesion in conjunction with clinical findings.     

Stem cell factor and interleukin-3 induce stepwise generation of erythroid precursor cells from a basic fibroblast growth factor-dependent hematopoietic stem cell line, A-6

A multipotent immature myeloid cell population was produced from a basic fibroblast growth factor (bFGF)-dependent hematopoietic stem cell line, A-6, when cultured with stem cell factor (SCF) replacing bFGF. Those cells were positive for stem cell markers, c-kit and CD34, and a myeloid cell marker, F4/80. Some cell fractions were also positive for Mac-1, a macrophage marker or Gr-1, a granulocytic maker, but negative for an erythroid marker TER119. They also showed the expression of mRNA for the myeloid-specific PU.1 but did not that for the erythroid-specific GATA-1. Among various cytokines, interleukin-3 (IL-3) induced erythroid precursor cells that expressed the erythroid-specific GATA-1 and beta-major globin. The quantitative analysis showed that erythroid precursor cells were newly produced from the immature myeloid cells by cultivation with IL-3. SCF and IL-3 induced stepwise generation of erythroid precursor cells from an A-6 hematopoietic stem cell line.     

Relationships between Colony Morphotypes and Oil Tolerance in Rhodococcus rhodochrous

A mucoidal strain of Rhodococcus rhodochrous was resistant to 10% (vol/vol) n-hexadecane, while its rough derivatives were sensitive. When the extracellular polysaccharide (EPS) produced by the mucoidal strain was added to cultures of the rough strains, the rough strains gained resistance to n-hexadecane. Thus, EPS confer tolerance to n-hexadecane in members of the genus Rhodococcus.