Minimum chemical requirements for adhesin activity of the acid-stable part of Candida albicans cell wall phosphomannoprotein complex

This study was conducted to define adhesive characteristics of the acid-stable moiety of the Candida albicans phosphomannoprotein complex (PMPC) on adherence of this fungus to marginal zone macrophages of the mouse spleen. Complete digestion of the acid-stable moiety (Fr.IIS) of the C. albicans PMPC with an alpha-mannosidase or hydrolysis with 0.6 N sulfuric acid destroyed adhesin activity, as determined by the inability of the soluble digests to inhibit yeast cell adherence to the splenic marginal zone. Fr.IIS adhesin activity was decreased following digestion with an alpha-1,2-specific mannosidase. Oligomannosyls consisting of one to six mannose units, which were isolated from the acid-stable part of the PMPC, did not inhibit yeast cell binding and thus do not function alone as adhesin sites in the PMPC. To gain more insight into the minimum requirements for adhesin activity, PMPCs were isolated from a Saccharomyces cerevisiae wild-type strain and from mutant strains mnn1, mnn2, and mnn4; the PMPCs were designated scwt/Fr.II, scmn1/Fr.II, scmn2/Fr.II, and scmn4/Fr.II, respectively. S. cerevisiae scmn2/Fr.II lacks oligomannosyl side chain branches from the outer core mannan, and scmn2/Fr.II was the only PMPC without adhesin activity. S. cerevisiae scwt/Fr.II, scmn1/Fr.II, and scmn4/Fr.II showed adhesin activities less than that of C. albicans Fr.II. These three S. cerevisiae PMPCs are generally similar to Fr. IIS, except that the S. cerevisiae structure has fewer and shorter side chains. Immunofluorescence microscopy show that the acid-stable part of the PMPC is displayed homogeneously on the C. albicans yeast cell surface, which would be expected for a surface adhesin. Our results indicate that both the mannan core and the oligomannosyl side chains are responsible for the adhesin activity of the acid-stable part of the PMPC.     

Effects of age and sex on sodium chloride sensitivity: association with plasma renin activity

The mechanism by which excessive NaCl intake raises blood pressure has not been fully clarified. The present study was undertaken in 87 Japanese inpatients with essential hypertension to investigate the interrelation among effects of age, sex and the renin-angiotensin system on NaCl sensitivity. After ingesting a regular NaCl diet (170 mmol/day) for one week, subjects were placed sequentially on a week of low NaCl diet (50 mmol/day) and a week of high NaCl diet (340 mmol/day). NaCl sensitivity defined as the difference in mean blood pressure between the low and high NaCl diets did not differ between genders. NaCl sensitivity was positively correlated with age and the change in PRA. The fall in PRA after NaCl loading was significantly smaller in women than in men. By multiple regression analysis, age and the change in PRA independently contributed to the change in mean blood pressure. Furthermore, the interaction between sex and the change in PRA was selected as a statistically significant variable. In conclusion, NaCl sensitivity of blood pressure is independently associated with age and the inadequate suppression of the renin-angiotensin system. Because the contribution of the change in PRA to NaCl sensitivity was greater in women than in men, the mechanism of blood pressure elevation after NaCl loading may differ between genders.     

Gel permeation chromatography using controlled-porosity glass. II. Polyacrylamide aqueous solutions

In a study of polyacrylamide in solutions we have required the rapid characterization on chromatographies. The application to the aqueous solution of the GPC using controlled-porosity glass has been examined from both the viewpoint of the effect of salt addition and the GPC mechanism. An adequate addition to neutral salt, 0.005M KCI to the eluent, gave rise to the elution behaviors being in accord with the hydrodynamic volume concept of the GPC separation.     

The influence of a fibre structure on optical loss in a graded-index fibre

For designing a fibre structure, the influence of structural parameters on optical loss is investigated experimentally for a graded-index fibre. The fibre with large cladding/outer-layer index difference and small cladding thickness is found to have large excess loss near excitation points, such as a launching point and a splicing point.     

Crystallographic Properties of Ge/Si Heterojunctions Fabricated by Wet Wafer Bonding

Ge/Si heterojunctions formed by wet wafer bonding were observed using transmission electron microscopy and energy-dispersive x-ray spectroscopy. For the samples annealed at 880°C, there was a transition layer at the heterointerface with modified regions in the Si and Ge extending 20 nm to 30 nm from the interface. In these modified regions, crystal defects were observed, and a large amount of Ge was detected on the Si side of the junction. For the samples annealed at 250°C or 350°C, the transition layers had an amorphous-like structure with a thickness of about 10 nm. No modified layer or enlargement of lattice spacing was observed.     

Control of nano-sized interlayer space of lamellar vanadyl benzylphosphate

Nano-sized interlayer space of lamellar vanadyl benzylphosphate was controlled by water content in starting solution. Depending on the water content, three types of lamellar vanadyl benzylphosphate having basal spacings of 1.4 nm, 1.9 nm and 2.3 nm were obtained. It was suggested that the difference in the concentrations of benzyl and hydroxyl groups in the interlayer leads to the variation of the interlayer space.     

Transport of direct dye into cellulose membrane

The dyeing process for a cellulose membrane–direct dye system is analyzed based on a parallel transport mechanism of surface and pore diffusion with Freundlich isotherm. Numerical solutions were obtained in order to clarify how the surface and pore diffusion resistances affect the uptake curve. The numerical solutions were also compared with an analytical solution for surface diffusion control to establish the range where the analytical solution can be considered as an acceptable approximation. The uptake curves in the cellulose membrane-chromophore (C.I. Direct Yellow 12) system in the presence of inorganic electrolyte were measured. The rate of adsorption and the maximum amount of adsorption increased with an increase in the concentration of those electrolytes. The rate of adsorption was approximately controlled by the surface diffusion rather than by pore diffusion. The surface diffusivities of the dye were little affected by either the concentration and or nature of the electrolyte.     

Two-temperature chemically-non-equilibrium modeling of argon induction plasmas with diatomic gas

A non-equilibrium modeling of argon–oxygen and argon–hydrogen induction thermal plasmas was performed without thermal and chemical equilibrium assumptions. Reaction rates of dissociation and recombination of diatomic gas and ionization were taken into account with two-temperature modeling. A substantial deviation from LTE exists near the torch wall in argon–oxygen induction plasmas under atmospheric pressure, while small deviation in argon–hydrogen plasmas results from the large collision frequency between electrons and hydrogen atoms.     

Radiation-induced bystander effects induce radioadaptive response by low-dose radiation

When normal human fibroblast cells (MRC-5) received a priming irradiation of 3-20 mGy 4 h prior to irradiation with 1000 mGy, the number of DNA double-stranded breaks (DSBs) decreased significantly to 18.2-18.7 per cell compared with 21 per cell when there was no priming irradiation. This result indicates that a priming irradiation of 3-20 mGy induces a radioadaptive response in MRC-5. The authors' previous study had indicated that DSBs induced by ≤ 20 mGy are due to a radiation-induced bystander effect. These findings suggest that radiation-induced bystander effects might contribute to induction of the radioadaptive response. To test this hypothesis, MRC-5 were suspended in lindane, an inhibitor of radiation-induced bystander effects, which was added to the medium for the priming irradiation of 3-20 mGy. Lindane inhibited the protective effect of priming irradiation on DSBs caused by subsequent irradiation with 1000 mGy. Thus, radiation-induced bystander effects may play a role in radioadaptive responses.