Stimulation of NK-like YT cells via leukocyte function-associated antigen (LFA)-1. Possible involvement of LFA-1-associated tyrosine kinase in signal transduction after recognition of NK target cells

The YTA-1 anti-LFA-1 alpha mAb activates protein tyrosine kinase (PTK), augments NK cytotoxicity, and induces proliferation of fresh CD3- large granular lymphocytes. We demonstrate here that LFA-1 is physically associated in the YT human NK-like cell line cells with a PTK(s) that is distinct from Src family PTKs such as Lck, Fyn, or Lyn. In vitro kinase assays revealed similar association of protein kinase activity with LFA-1 in normal CD3- large granular lymphocytes. Tyrosine phosphorylation of the proteins associated with LFA-1 drastically increased in YT cells after stimulation with NK-sensitive K562 cells but not with NK-resistant P815 cells. Furthermore, pretreatment of YT cells with TS1/22 anti-LFA-1 alpha and TS1/18 anti-LFA-1 beta mAbs abrogated not only the cytotoxicity against K562 cells but also an increase in tyrosine phosphorylation of LFA-1-associated molecules induced by K562 stimulation. These results provide biochemical evidence that the PTK(s) associated with LFA-1 is involved in the signal transduction that follows the recognition of NK target cells.     

Primary structure of the novel bacterial rhodopsin from extremely halophilic archaeon Haloarcula japonica strain TR-1

A novel bacterial rhodopsin was identified in Haloarcula japonica strain TR-1. The gene encoding the bacterial rhodopsin was cloned and sequenced. The structural gene consisted of an open reading frame of 750 nucleotides encoding 250 amino acids. The deduced amino acid sequence of the Ha. japonica bacterial rhodopsin showed the highest homology to those of cruxrhodopsins.     

Nuclear targeted suppression of NF-kappa B activity by the novel quinone derivative E3330

The activation of NF-kappa B consists of at least three steps: degradation of I kappa B alpha, translocation of NF-kappa B into the nucleus, ai post-translational modification of NF-kappa B (e.g., phosphorylation of p65). In the present study, we found that a novel quinone derivative E3330 selectively inhibited NF-kappa B-mediated gene expression without affecting any of these steps. E3330, when included in the culture medium, suppressed NF-kappa B DNA-binding activity in PMA-induced Jurkat cell nuclear extracts, suggesting that the inhibition by E3330 of NF-kappa B-mediated gene expression was due to its ability to suppress NF-kappa B DNA-binding activity. Fractionation of the nuclear extracts by column chromatography revealed that a nuclear factor enhanced NF-kappa B DNA-binding activity and that this enhancing activity was interrupted after treatment with E3330. Moreover, a major polypeptide with a molecular mass of 40 kDa was found to be in the highly purified fraction containing the NF-kappa B-enhancing activity and predominantly bind E3330. Taken together, these results suggest that the NF-kappa B activity, after dissociation from I kappa B, is enhanced by a nuclear factor that is active irrespective of PMA treatment, and the nuclear factor-mediated enhancement is selectively inhibited by E3330. Thus, we conclude that E3330 may belong to a novel class of anti-NF-kappa B drugs.     

Neurotoxicodynamics of the interaction between ciprofloxacin and foscarnet in mice

The potential for convulsions induced by the coadministration of ciprofloxacin (CPFX) and foscarnet (PFA) may be due not to a change in the distribution of CPFX to the brain but to a potential CPFX-induced inhibition of gamma-aminobutyric acid (GABA)-GABA(A) receptor binding in the presence of PFA.     

Photoluminescence excitation spectroscopy of the dense exciton gasinvolved in the lasing transition in ZnSe epitaxial layers

The lasing transition in ZnSe epitaxial layers has been investigated at 77 K. The lowest lasing threshold (I_th) was achieved when the layers were resonantly excited at the photon energy of the exciton level. It was found that the exciton level at the excitation intensity just above the I_th was red-shifted by about 16 meV compared with the free exciton line (2.792 eV) under weak excitation condition. The energy difference between the exciton line and the lasing peak was about 19 meV at I=I_th and increased with increasing excitation intensity up to I=8×I_th. This suggests that the stimulated emission occurs due to the inelastic exciton-exciton scattering process at this temperature     

Kinetic analysis of benzyl alcohol oxidation by alcohol oxidase in aqueous—organic two-phase systems

Alcohol oxidase-catalyzed oxidation of benzyl alcohol to benzaldehyde was studied in three two-liquid phase systems involving butyl acetate, xylene and n-decane. A more highly hydrophobic solvent resulted in more favorable partitioning of the substrate into the aqueous phase and less deleterious effect on the enzyme activity. As a result, the overall production of aldehyde was highest with the n-decane system and lowest with the butyl acetate system. In addition, the organic solvent served as an extractant for the product, which acted both as a competitive inhibitor and as a denaturant of the enzyme. The time courses of benzaldehyde production were simulated by a simple mathematical model assuming Michaelis–Menten kinetics in the aqueous phase, enzyme deactivation by organic solvents and the equilibrium partitioning of the reagents between the two phases.     

The Job Content Questionnaire (JCQ): an instrument for internationally comparative assessments of psychosocial job characteristics

Part I discusses the Job Content Questionnaire (JCQ), designed to measure scales assessing psychological demands, decision latitude, social support, physical demands, and job insecurity. Part II describes the reliability of the JCQ scales in a cross-national context using 10,288 men and 6,313 women from 6 studies conducted in 4 countries. Substantial similarity in means, standard deviations, and correlations among the scales, and in correlations between scales and demographic variables, is found for both men and women in all studies. Reliability is good for most scales. Results suggest that psychological job characteristics are more similar across national boundaries than across occupations.     

Kinetic study of isotopic exchange reaction between hydrogen and water vapor over a pt/sdbc hydrophobic catalyst sheet

The isotopic exchange reaction between hydrogen and water vapor was studied for the temperature range 313 K to 353 K using 2.2% platinum supported on a hydrophobic styrene-divinylbenzene copolymer (SDBC) sheet. With increasing relative humidity, the exchange rate increased, giving a stepped profile with a knee shape, and the reaction order with respect to hydrogen increased from almost zero to first order. In order to explain this unusual behavior, a simple kinetic model was proposed assuming that the water molecules are adsorbed in a multilayer on the platinum surface, and are subject to the exchange equivalent to finite number of layers. On the other hand, this multilayer of adsorbed water inhibits the transfer of HD to the platinum surface.     

Conducting properties of radical-cation salts of BEDT-TTP

Compressed pellets of BEDT-TTP chemically doped by such oxydizing reagents as I₂ and Br₂ have shown high conductivity. Electrochemically obtained EDT-TTP salts have also exhibited metallic conductivity.     

Growth and protective potentials of attenuated strains of equid herpesvirus 1 in the lungs of mice

Attenuated equid herpesvirus 1 (EHV-1) strains with different passage histories in bovine kidney cells (BKC), i.e. BK77, BK161, BK271 and BK343, were examined for their growth in mouse lungs after intranasal inoculation. BK77 and BK161 were recovered from lungs with almost the same titres, and were found to be about 100 times lower than that of the parent HH1 strain. The growth abilities of high-passaged BK271 and BK343 were markedly reduced. Although partial growth of BK343 in the lungs of athymic nude mice was observed, the virus was almost eradicated from their lungs within 1 week. By contrast, the parent HH1 persisted in the lungs of nude mice for at least 1 week. The mice immunized with the BKC-passaged viruses were partially protected against subsequent challenge with the parent HH1. Antibodies were detected by ELISA. These results demonstrate that, although serial BKC-passage lowered the growth ability of the parent HH1, the descendant viruses still have a partial protective potential in mice.