Inhibitory Effect of Glycerin on Vibrio parahaemolyticus and Salmonella

In a study of the effect of glycerin in transport media on Vibrio parahaemolyticus and Salmonella, it was found that a concentration of 30% glycerin was highly inhibitory for V. parahaemolyticus and to a lesser degree for Salmonella. The incorporation of peptone or human feces in media did not reduce the inhibitory effect of glycerin. In media with 15% glycerin, viable counts of V. parahaemolyticus and Salmonella increased after 24 hr of incubation both in the presence and absence of feces. Due to the concurrent increase in the total bacterial count in the media containing feces, no enrichment effect was noted.     

Heritability of Eating Behavior Assessed Using the DEBQ (Dutch Eating Behavior Questionnaire) and Weight‐related Traits: The Healthy Twin Study

The heritability of eating behavior and body weight–related traits in Asian populations has not been reported. The purpose of this study was to estimate the heritability of eating behavior and the body weight–related traits of current weight and self‐reported past weight among twins and their families. Study subjects were 2,144 Korean, adult, same‐sex twins and their families at the ages between 20 and 65 years (443 monozygotic (MZ) and 124 dizygotic (DZ) twin pairs, and 1,010 individuals of their family). The Dutch Eating Behavior Questionnaire (DEBQ) was used to assess three eating behavior subscales measuring restraint, emotional eating, and external eating. A variance component approach was used to estimate heritability. After consideration of shared environmental effects and adjustment for age and sex effects, the heritability estimates ± s.e. among twins and their family members were 0.31 ± 0.036 for restraint, 0.25 ± 0.098 for emotional eating, 0.25 ± 0.060 for external eating, 0.77 ± 0.032 for measured current body weight, and 0.70 ± 0.051 for self‐reported weight at 20 years old. The three DEBQ subscales were associated with all weight related traits after adjustment for age and sex. These results suggest eating behaviors and weight‐related traits have a genetic influence, and eating behaviors are associated with obesity indexes. Our findings from Korean twin family were similar to those reported in Western populations.     

Stable ester conjugate between the Saccharomyces cerevisiae RAD6 protein and ubiquitin has no biological activity.

The RAD6 gene of Saccharomyces cerevisiae, which encodes a ubiquitin-conjugating enzyme, is required for DNA repair, DNA damage-induced mutagenesis and sporulation. To evaluate the biological relevance of the thioester adduct between RAD6 protein and ubiquitin, formed as an obligatory, transient intermediate during ubiquitin conjugation to substrates, we altered cysteine 88 in RAD6 to serine. Esterification with ubiquitin occurs at serine 88 in the mutant protein, but conjugation of ubiquitin to the test substrate histone H2A is inactivated. Phenotypically, strains harboring the rad6 Ser88 allele are indistinguishable from rad6 deletion (rad6 delta) mutant cells. These findings argue against ligation of ubiquitin at cysteine 88 acting as a functional switch of a cryptic biochemical activity in RAD6.     

Selection and proliferation of rapid growing cell lines from embryo derived cell cultures of yew tree (Taxus cuspidata Sieb. et Zucc)

Calli were induced from 300,000 embryos isolated from immature to mature stage of seeds collected on late September from 14 elite trees. When the embryos were cultured onto plastic Petri-dish containing 20 mL of modified B5 basal medium supplemented with 3% (w/v) sucrose, 500 mg/L casein hydrolysate, 250 mg/L myo-inositol, 0.5% (w/v) polyvinyl polypyrrolidon (PVPP), 2×MS vitamins, 0.5 mg/L gibberellic acid, and 10 mg/L 2,4-D after 2 weeks of culture, yellowish-white calli were immediately formed on the surfaces of embryos, and subcultured for 4 weeks in same culture medium. Because most of calli maintained for more than 3 months were revealed differences in their colors, surface texture, and growth rate, visual selection was made for first round screening. When the size of visually selected calli larger than 19 mm in their diameter were inoculated, persistent proliferation was observed. Among the plating methods tested for the selection of rapid growing cell lines at single cell and/or small cell aggregate level, 2-layer spread plating revealed as the best for single cell cloning. To enhance cell growth and maintain high rate of viability for long-term culture of yew cells in bioreactor, final cell volume less than 50% in SCV seemed to be the best. Time course study revealed that 30% of inoculum density was suitable for fed batch culture. Among the tested conditional media, the rate of 1∶2 (old medium: fresh medium) was recorded at the best for cell growth.     

Deactivation ofCandida rugosa lipase

Summary Deactivation ofCandida rugosa lipase was found to be complex. Hydrophobic interaction induced by iso-octane influenced the initial phase of deactivation, and increased the turn-over rate of the intermediate in the transition phase. After urea-treatment the structure of the last phase was not further influenced by thermal treatment, whereas that of initial phase was more sensitive to temperature change. Charge interaction was important in maintaining the structure during the deactivation, and especially anion charge might be a major factor.     

A nuclear protein associated with cell divisions in plants

A nuclear protein, present in carrot meristems and rapidly proliferating cultured cells of carrot (Daucus carota L.) has been identified by the use of a monoclonal antibody (MAb 21D7). By combining the techniques of two-dimensional polyacrylamide gel analysis and blotting separated proteins onto nitrocellulose sheets, it was shown that the antibody detected a single polypeptide of apparent molecular mass (M _r) of 45000 and an isoelectric focusing point (pI) of 6.7. This protein was found by subcellular fractionation and immunofluorescence to be highly concentrated in the nucleoli of somatic and zygotic embryos of a wide range of plants. It was not detectable in logarthmically growing cells ofEscherichia coli, yeast, embryos ofDrosophila melanogaster or cultured C3H mouse cells. These data indicate that this protein is a highly conserved non-histone protein associated with nuclei of rapidly dividing plant cells.Abbreviations M _r apparent molecular mass - Da dalton - Ig immunoglobulins - MAb monoclonal antibody - SDS-PAGE sodium dodecyl sulfate-polyacrylamide gel electrophoresis - 2-D gel two-dimensional gel electrophoresis - 2,4-D 2,4-dichlorophenoxyacetic acid     

The ontogeny of the vascular cambium inGinkgo biloba roots

Observation was made on early ontogeny of vascular cambium in the developing root ofGinkgo biloba L. After completion of root elongation, the vascular meristem gradually acquires cambial characteristics. Strips of the periclinal division of cells in transverse section are observed on the inner side of phloem when the primary xylem and phloem in the stele have been established. The strips are united into a continuous layer between phloem and xylem. In tangenital section, the procambium shows a homogeneous structure, which is initially composed of short cells with transverse end walls and subsequently, of long cells with tapering ends. Then, the procambium is organized into two systems of cells; axial strands of short cells with transverse end walls resulting from the sporadic transverse divisions of long cells, and long cells with tapering ends. Still later, the short cells are divided frequently in a trasverse plane exhibiting one or a few cells in width and several decades of cells in height, while the long cells are elongated. The frequency of transverse divisions of the short cells decreases in subsequent stages. Eventually, the short cells in axial strands are vertically separated from one another by the elongation of neighboring long cells and by the decrease in the frequency of transverse divisions of short cells themselves. Cambial initials occur in two forms; ray initials a few cells in height and one cell in width derived from the short cells, and fusiform initials with tapering ends derived from the long cells.     

In vitro shoot regeneration from leaf mesophyll protoplasts of hybrid poplar (Populus nigra x P. maximowiczii)

Summary Protoplasts were isolated from leaf mesophyll of hybrid poplar (Populus nigra X P. maximowiczii) with a mean yield of 10.4 x 10⁶ protoplasts per g fresh weight using 2.0% Cellulase Onozuka R-10, 0.8% Macerozyme R-10, 1.2% Hemicellulase, 2.0% Driselase, and 0.05% Pectolyase Y-23 with CPW salts solution containing 0.6 M mannitol, 0.002 M DTT, 3 mM MES at pH 5.6. A liquid plating method produced the highest frequency of dividing protoplasts (48.6%) using an MS medium without NH₄NO₃. The highest percent of colony formation was 22.8%, produced with fabric supported semi-solid (0.5% w/v) agar plating method using the same culture medium. Growing cell colonies and/or micro-calli were transferred to a fresh semisolid agar medium containing 0.44 M BAP and 9.0 M 2,4-D. Multiple shoots were produced from protoplast-derived callus after culture on MS medium containing 6.8 M zeatin. After root induction on half-strength MS medium that lacked growth regulators, shoots were transferred to pots containing artificial soil mix.Abbreviations CPW Cell and Potoplast Wash solution - LPM Liquid Plating Method - LDM Liquid Drop Method - HDM Hanging Drop Method - FSPM Fabric supported Semi-solid agar Plating Method - DTT Dithiothreitol - MES 2-(N-morpholino) ethane sulfonic acid - BAP 6-benzylaminopurine - 2,4-D 2,4-dichlorophenoxy acetic acid - NAA -naphthalene acetic acid - MS Murashige and Skoog (1962)     

Triterpene glycosides from Schefflera octophylla.

In addition to 3-epi-betulinic acid, three triterpene glycosides were isolated from leaves of Schefflera octophylla. The structures of the glycosides have been determined as 28-O-[alpha-L-rhamnopyranosyl(1----4)-O-beta-D-glucopyranosyl(1----6)-be ta-D- glucopyranosides of 3 alpha-hydroxy-lup-20(29)-ene-23,28-dioic acid, 3 alpha,11 alpha- dihydroxy-lup20(29)-ene-23,28-dioic acid and 3-epi-betulinic acid by spectroscopic data and chemical transformations. The last two compounds were found for the first time in the plant kingdom.