Generation of a purely clonal defective interfering influenza virus

Defective interfering (DI) influenza viruses carry a large deletion in a gene segment that interferes with the replication of infectious virus; thus, such viruses have potential for antiviral therapy. However, because DI viruses cannot replicate autonomously without the aid of an infectious helper virus, clonal DI virus stocks that are not contaminated with helper virus have not yet been generated. To overcome this problem, we used reverse genetics to generate a clonal DI virus with a PB2 DI gene, amplified the clonal DI virus using a cell line stably expressing the PB2 protein, and confirmed its ability to interfere with infectious virus replication in vitro. Thus, our approach is suitable for obtaining purely clonal DI viruses, will contribute to the understanding of DI virus interference mechanisms and can be used to develop DI virus‐based antivirals.     

Effect of Clostridium perfringens Beta Toxin on Blood Pressure of Rats

Guanethidine treatment or adrenal medullectomy significantly inhibited the elevation in blood pressure induced by Clostridium perfringens beta toxin, and the combination of the two drastically reduced the pressure rise, to less than 19% of that in control rats. When rats were pretreated with tetrodotoxin or hexamethonium, the toxin-evoked rise was significantly inhibited. Elevation in blood pressure induced by the toxin in spinal rats tended to be less than that in control rats. When investigated by a microscopical technique, arteriolar constriction in the mesenteric vasculature was observed after the blood pressure elevation induced by the toxin reached a maximum. Blood flow in the skin decreased with an increase in blood pressure following intravenous injection of the toxin. It is concluded that beta toxin acts on the autonomic nervous system and produces arterial constriction.     

Candida albicans and Candida parapsilosis Rapidly Up-Regulate Galectin-3 Secretion by Human Gingival Epithelial Cells

Galectin-3 is a β-galactoside-binding C-type lectin that plays an important role in innate immunity. The purpose of this study was to determine whether Candida albicans and Candida parapsilosis up-regulate galectin-3 secretion by human gingival epithelial cells and gingival fibroblasts. Ca9-22, a human gingival epithelial cell line, and human gingival fibroblasts were incubated in the presence or absence of C. albicans or C. parapsilosis without serum. Levels of secreted human galectin-3 in culture supernatants were measured by enzyme-linked immunosorbent assay. We also pretreated Ca9-22 cells with cytochalasin D (an actin polymerization inhibitor), ALLN (a calpain inhibitor) and LY294002 [a phosphatidylinositol-3 kinase (PI3K) inhibitor] to determine whether the up-regulation of galectin-3 secretion was mediated by cytoskeletal changes, protease activity, or PI3K signaling. Galectin-3 secretion was significantly and rapidly up-regulated by live C. albicans and C. parapsilosis, as well as heat-killed C. albicans. In addition, cytochalasin D, LY294002 and ALLN did not inhibit the up-regulation in galectin-3 secretion. These results suggest that both live and heat-killed C. albicans and C. parapsilosis may increase the activity of the innate immune system and invasion by other microorganisms via up-regulation of galectin-3 secretion.     

Ring chromosome 15 in a mother and her children

Summary A case of ring chromosome 15 passed on to the index patient's two children is reported, and possible reasons for the infrequent records of inheritance of ring chromosome are suggested.     

PISTIL DEVELOPMENT AND PARIETAL PLACENTATION IN THE PSEUDOMONOMEROUS OVARY OF ZELKOVA SERRATA (ULMACEAE)

Development of female flowers in Zelkova serrata was observed using epi-illuminated microscopy and scanning electron microscopy, with particular attention given to placentation. After the inception of staminodial primordia, the floral apex becomes flat, and the first and subsequently the second carpel primordia appear at opposite comers of the pistil primordium. Inside each carpel primordium a fossette forms. Through differential growth this depression becomes clear and the carpel wall encircles one side of the future placental region. The placental region is detectable even in early stages, but clear signs of ovule inception appear late when the placental region is elevated onto one side of the ovary wall by intercalary growth. Although the relative size of the two carpels varies among flowers, the placental position always appears to be the border between the two carpels and the floral apex. This suggests that the placentation of Zelkova is parietal. The ovule position in tricarpellate ovaries also suggests an evolutionary derivation from ovaries with parietal placentation. Parietal placentation appears to be the original condition in Urticales.     

Changes in membrane constituents and chemiluminescence in vitamin E-deficient red blood cells induced by the xanthine oxidase reaction

The oxidation of vitamin E-deficient rat red blood cells (RBCs) induced by the hypoxanthine-xanthine oxidase (HX-XOD) system has been performed in an aqueous suspension. The generation of chemiluminescence and the accumulation of thiobarbituric acid-reactive substances (TBARS) were observed initially and were followed by hemolysis. Interestingly, the total counts of chemiluminescence were closely related to the amount of TBARS. The predominant change of membrane proteins induced by the reaction was the depletion of spectrin bands in gel electrophoresis. When RBC ghosts were oxidized with HX-XOD, the sulfhydryl (SH) groups of membrane proteins decreased at an early stage of the incubation, which was coincident with the above protein alteration. Membrane alpha-tocopherol suppressed not only the formation of TBARS but also chemiluminescence and hemolysis; nevertheless, it did not inhibit the protein damage and the loss of SH groups. Moreover, it was concluded that the chemiluminescence observed during the oxidation of RBC membranes was associated mainly with the peroxidation of lipids and only to a minor extent with the oxidation of proteins.     

Primary photoprocesses of phytochrome. Picosecond fluorescence kinetics of oat and pea phytochromes

The primary photoprocesses of etiolated oat and pea phytochromes (Pr forms) are diffusion-modulated by the microscopic viscosity within the chromophore pocket. The chromophore pocket is preferentially accessible to glycerol but not to Ficoll. Glycerol preferentially retarded the rate (rate constant ca. 1-2 X 10(10) s-1) of the initial reaction from the Qy excited state of phytochrome, whereas it increased the long fluorescence lifetime (nanosecond) component that can be attributed to either an emitting intermediate or to modified/conformationally heterogeneous phytochrome populations. The picosecond time-resolved fluorescence spectra of different phytochrome preparations (i.e., full-length vs 6/10-kDa NH2-terminus truncated forms of phytochromes from monocot and dicot plants) revealed no significant differences. The spectra in the picosecond time scale showed no spectral shifts, but at longer time scales of up to approximately 1.90 ns, significant blue spectral shifts were observed. The shifts were more in the truncated than in the full-length pea phytochrome. Comparison of the fluorescence decay data and the picosecond time-resolved fluorescence spectra suggests differences in conformational flexibility/heterogeneity among the preparations of the monocot vs dicot phytochromes and the full-length native vs the amino terminus truncated phytochromes.     

Detection of point mutation in the tyrosinase gene of a Japanese albino patient by a direct sequencing of amplified DNA

Summary Enzymatic DNA amplification and direct DNA sequencing were used to detect a mutation in the tyrosinase gene of an albino patient. Single-base change could be detected by direct sequencing. This base change (G to A) is thought to result in an amino acid change (Arg to Gln) in tyrosinase of the patient.