Behavioral characteristics of old female Japanese monkeys in a free-ranging group

Fourteen female Japanese monkeys of the Arashiyama-B group ranging in age from 11 to 29 years were observed to elucidate the behavioral characteristics of aging monkeys. A positive significant correlation was found between the occurrences of rest and age, and a negative significant correlation between the occurrences of auto-grooming and age. Younger female monkeys tended to be in contact with or in proximity to group members, while older female monkeys tended to spend much more time alone. As for the grooming interactions, younger female monkeys more often groomed others than did older female monkeys. Also, the former engaged in grooming more frequently than in being groomed, while the latter spent more time in being groomed than in grooming. The old female monkeys showed no marked decline in rank, but some of them were surpassed by their adult daughters.     

Enhancing the fungicidal activity of amphotericin B via vacuole disruption by benzyl isothiocyanate,a cruciferous plant constituent

Amphotericin B (AmB), a typical polyene macrolide antifungal agent, is widely used to treat systemic mycoses. In the present study, we show that the fungicidal activity of AmB was enhanced by benzyl isothiocyanate (BITC), a cruciferous plant-derived compound, in the budding yeast, Saccharomyces cerevisiae. In addition to forming a molecular complex with ergosterol present in fungal cell membranes to form K⁺-permeable ion channels, AmB has been recognized to mediate vacuolar membrane disruption resulting in lethal effects. BITC showed no effect on AmB-induced plasma membrane permeability; however, it amplified AmB-induced vacuolar membrane disruption in S. cerevisiae. Furthermore, the BITC-enhanced fungicidal effects of AmB significantly decreased cell viability due to the disruption of vacuoles in the pathogenic fungus Candida albicans. The application of the combinatorial antifungal effect of AmB and BITC may aid in dose reduction of AmB in clinical antifungal therapy and consequently decrease side effects in patients. These results also have significant implications for the development of vacuole-targeting chemotherapy against fungal infections.     

The Schizosaccharomyces pombe cdc6 gene encodes the catalytic subunit of DNA polymerase δ

The cdc6 mutants of Schizosaccharomyces pombe have been classified as being defective in progression through the G2 phase of the cell cycle. We cloned an S. pombe gene that could complement the temperature-sensitive growth of the cdc6-23 mutant. Unexpectedly, the cloned gene was allelic to pol3, which encodes the catalytic subunit of DNA polymerase δ. Integration mapping confirmed that cdc6 and pol3 are identical. The cdc6-23 mutant carries one amino acid substitution in the conserved N3 region of Pol3. Received: 17 October 1996 / Accepted: 19 November 1996     

Purification and characterization of glyoxalase I from Pseudomonas putida

Glyoxalase I was purified to apparent homogeneity from Pseudomonas putida. The enzyme was a monomer with a molecular weight of 20,000. The enzyme was most active at pH 8.0. The Km values for methylglyoxal and 4,5-dioxovale-rate are 3.5 mM and 1.2 mM, respectively. Contrary to the case of eukaryotic enzymes, chelating agents showed little inhibitory effects on the enzyme activity. Among the metal ions tested, Zn++ specifically and completely inhibited the activity of the enzyme at a millimolar level. The properties of bacterial glyoxalase I were quite different from mammalian and yeast enzymes.     

Chemical, physicochemical and spectrophotometric properties of crystalline chlorophyll-protein complexes from Lepidium virginicum L

Two kinds of water-soluble chlorophyll-protein complexes were prepared from leaves of Lepidium virginicum L., one (CP661) from the plant cultivated in a green house from seeds collected near Mono Lake, CA, and the other (CP-663) from a plant collected at Narashino, Chiba, Japan, by ammonium sulfate fractionation followed by column chromatography on DEAE-cellulose and Sephacryl S-200. The chlorophyll . proteins were further purified by crystallization. CP661 has absorption peaks at 661, 468, 439, 419, 380, 339 and 272 nm. CP663 had absorption peaks at 663, 469, 438, 419, 379, 338 and 272 nm. Estimated molecular weights were 78 000 for CP661 and 80 000 for CP663 by gel filtration chromatography and 83 000 for CP661 and 107 000 for CP663 by an equilibrium sedimentation method. 1 mol chlorophyll . protein contained 4 mol chlorophyll a and b with ratios of 1.0 in CP661 and 1.6 to 1.9 in CP663, but no carotenoids. These characters are different from those of chlorophyll-protein complexes which are prepared from the thylakoid membranes of chloroplasts with detergents.     

Fragile X expression in thymidine-prototrophic and auxotrophic human-mouse somatic cell hybrids under low and high thymidylate stress conditions

Expression of the fragile X site fra(X)(q27.3) was studied in thymidine-prototrophic and auxotrophic human-mouse somatic cell hybrids. In these cells, low thymidylate stress, achieved by 5-fluoro-2'-deoxyuridine (FdU) treatment and by limiting the exogenous supply of thymidine (dT), induced fragile X expression. High thymidylate stress, produced by supplying excess amounts of dT, was also effective in inducing fragile X expression, even in a hybrid clone that retained a fragile X chromosome as the only human chromosome; addition of deoxycytidine (dC) completely abolished this effect. In contrast, 5-bromo-2'-deoxyuridine (BrdU) did not induce fragile X expression. Cell-cycle analysis of BrdU-deprived thymidine-auxotrophic hybrid cells indicated that one round of DNA replication under thymidylate stress conditions is sufficient for fragile X expression. Our results suggest that the expression is an intrinsic property of the fragile site itself, which is believed to be composed of replicon clusters with pyrimidine-rich DNA sequence(s).     

Studies on the Glucanase of Sclerotinia Libertiana

Glucanase-treatment of yeast cells was shown to increase the glucose fermenting activity, and decrease the sucrose and maltose fermenting activity. Also, lipase–and phospholipase–treatment decreased the fermenting activity on these sugars. However, the effects on the disaccharide fermenting activity could be reversed under various growth conditions of the yeast cells.

From these results, structural factors envolved in the transport of fermentable sugars into yeast cells are discussed.     

Effect of molar ratio of fluorescent dye to IgG on the detection of lymphocyte surface immunoglobulins by immunofluorescence

Labeled antibodies with different F/P molar ratios of FITC to protein (F/P molar ratio) were used for the detection of surface immunoglobulin (S-Ig) of human and mouse lymphocytes by membrane immunofluorescence, and the following results were obtained. 1. The percentage of S-Ig bearing cells increased markedly when labeled anti-human H- or L-chains antibodies were used with higher F/P molar ratios. The investigation of frozen kidney sections of mice injected with human immunoglobulin revealed that such an increase of the positive ratio in S-Ig was caused by increased non-specific adsorption of the fraction of labeled antibody with a high F/P molar ratio. 2. This non-specific adsorption phenomenon was observed at various intensities in materials from different species; materials from mcie showed less non-specific adsorption than those from humans. 3. It was possible to exclude reactivity with an Fc receptor using the top one third of the supernatant of labeled antibody centrifuged at 150,000 for 30 min.     

Characterization of translucent segments observed in an smbA mutant of Escherichia coli

Abstract The smbA gene of Escherichia coli is essential for cell proliferation. The smbA2 mutant shows cold-sensitive colony formation at 22°C. A novel morphological phenotype, formation of a translucent segment at midcell or at a cell pole, was observed by phase-contrastt microscopy at a high frequency in the smbA2 mutant cells incubated in L medium lacking NaCl at 22°C, but not observed in L medium containing 1% NaCl or 20% sucrose at the same temperature. No translucent segment was observed in the wild-type cells in any of the media used. Electron microscopic observation revealed that the translucent segments resulted from the enlargement of a periplasmic space by separation of the inner membrane from the peptidoglycan layer and the outer membrane.