Effect of glutamine on protein synthesis in isolated intestinal epithelial cells

The purpose of this study was to determine the etiologic factors of denture stomatitis. Fifteen subjects with clinical evidence of localized simple denture stomatitis, fifteen subjects without clinical signs of denture stomatitis, and forty-five subjects with clinical evidence of generalized simple denture stomatitis were investigated clinically and mycologically. Subjects were evaluated according to age, sex, duration of denture usage, smoking habits, frequency of denture brushing, overnight denture wearing, pH level of saliva and degree of candidal colonization and candidal formation. Salivary samples and swabs were taken from the palate and the mucosal surfaces of the dentures investigated mycologically in order to identify the yeast colonies. Smears were taken from the palate and investigated in order to identify candidal formation. No statistically significant relationship was found between denture stomatitis and age, sex, duration of denture usage, frequency of denture brushing, overnight denture wearing or pH level of saliva. There was however, a statistically significant relationship between denture stomatitis and denture hygiene, smoking habits, candidal colonization and candidal formation.     

Development of a liquid tin microjet target for an efficient laser-produced plasma extreme ultraviolet source

A regenerative tin liquid microjet target was developed for a high average power extreme ultraviolet (EUV) source. The diameter of the target was smaller than 160 microm and good vacuum lower than 0.5 Pa was maintained during the operation. A maximum EUV conversion efficiency of 1.8% at the Nd:yttrium-aluminum-garnet laser intensity of around 2 x 10(11) Wcm(2) with a spot diameter of 175 microm (full width at half maximum) was observed. The angular distribution of the EUV emission remained almost isotropic, whereas suprathermal ions mainly emerged toward the target normal.     

Inhibitory effect of zinc on beta-hexosaminidase release from RBL-2H3 cells by synthetic chemicals

The effects of foods and chemicals related to food hygiene on degranulation were evaluated using a method for assaying the enzyme activity of beta-hexosaminidase as an index of chemical mediator release from RBL-2H3 cells in vitro. Using a previously developed assay system, we had found a large number of inhibitors and promoters of degranulation of RBL-2H3 cells. In the present study, we examined the inhibitory effect of zinc chloride on the degranulation (beta-hexosaminidase release) from RBL-2H3 cells with or without antigen in the presence of the degranulation-promotive chemicals, namely, 4 food additives, 7 pesticides and 2 veterinary drugs. These promotive chemicals were classified into two types on the basis of inhibitory profile by zinc chloride: 1) those which showed marked degranulation-inhibitory action when the cells were stimulated with antigen, such as butylhydroxyanisole, dibutylhydroxytoluene, EPN, cis- and trans-permethrin, prothiofos, pyridaben, terbufos, 2) those which showed marked degranulation-inhibitory action whether the cells were stimulated with antigen or not, such as butyl p-hydroxybenzoate, o-phenylphenol, bitertanol, salinomycin. In conclusion, zinc had a dramatic inhibitory effect on enhanced degranulation induced by synthetic chemicals in vitro.     

Effects of veterinary drugs on beta-hexosaminidase release from rat basophilic leukemia cells (RBL-2H3)

Little is known about the effects of residual veterinary drugs on the allergic reaction, except for the antigenicity of antibiotics and synthetic antimicrobials. Therefore, 59 kinds of veterinary drugs were investigated for their effects on the IgE receptor-mediated beta-hexosaminidase release from RBL-2H3 cells as an index of immediate allergic reaction. We found that the antibiotics chlorotetracycline, doxycycline, monensin, the synthetic antimicrobial pyrimethamine and the steroid hormone testosterone inhibited beta-hexosaminidase release. Most of the veterinary drugs showed no action, though the ionophores lasalocid, salinomycin and the steroid hormone hexestrol promoted beta-hexosaminidase release from injured cells. Based on the residual levels of these drugs and the frequencies of detection in actual food samples, it seems unlikely that these drugs have any immediate allergic effect in practice.     

A tapered parallel plate waveguide for frequency up-conversion of terahertz radiation

A tapered parallel plate waveguide was developed for frequency up-conversion experiments in the terahertz (THz) region by flash ionization. The element at the plasma-source-wave interaction area determines the conversion efficiency. It causes THz pulses to converge to a narrow plate separation, which is smaller than the wavelength. The waveguide exhibited good performance for transmitting p-polarized THz pulses in a 50 μm separation, making it suitable for flash ionization experiments.     

An organo-metallic polymer used in powder metallurgy: The effect of polycarbosilane in iron-chromium alloy

A new material was developed by introducing an organo-metallic polymer into powder metallurgy. In the uniform mixture of Fe- 13Cr^* alloy powder and polycarbosilane (PC) usingn-hexane, the Fe-13Cr particles were coated with PC. The product of Fe-13Cr + 10wt% PC, obtained by hot-pressing the mixture, was subjected to an oxidation test, high-temperature hardness measurement and a wear resistance test, and found to be superior in all respects to that without the PC addition. The structure was observed by transmission electron microscope and it was found that grains of CrSi₂ and Cr₇ C₃ about 0.1m in size, dispersed uniformly in the Fe-13Cr + 10% PC, contributed to improvement of the mechanical properties. Observation by scanning electron microscope showed some difference in the formation of the oxidation film between Fe-13Cr and Fe-13Cr+10% PC. This new alloy, while adding an organo-metallic polymer to powder metallurgy, has several outstanding features with the possibility of many applications in the future.     

Occurrence of an organochlorine synergist S-421 in fish and shellfish

S-421 is a synergist for pyrethroid and organophosphorus pesticides, and is widely used in termiticides or commercial household insecticides. S-421 is mutagenic, stable and ubiquitous in the environment, and has been detected in household dust, surface water, sediments and rain-water. Here we describe the concentration of S-421 residues in domestic and imported fish collected in Osaka. S-421 was extracted with acetone/hexane, purified through silica gel 40 and quantified by ECD-GC. S-421 was detected in 36 out of 44 samples of domestic fish and shellfish analyzed, at a level of < 0.2 to 2.3 ng/g (mean: 0.6 ng/g), and in 27 out of 43 imported samples at a level of < 0.2 to 1.0 ng/g (mean: 0.2 ng/g). The levels of S-421 detected in fish were lower than those of DDTs and almost the same as those of HCHs. More attention should be paid to the behavior in the environment of S-421, as well as other persistent organochlorine pollutants, such as HCHs, DDTs and chlordane.