Immunostimulation of antibody-producing cells and humoral antibody to fish bacterins by a biological response modifier

Numbers of splenic antibody-producing cells and humoral antibody titres were elevated during immunization regimes in rainbow trout when the bacterins Yersinia ruckeri or Aeromonas salmonicida O-antigen preparations were mixed with the immunostimulator FK-565. Fish sampled 14 days after injection showed a marked increase in the immune response when doses of 5, 10 or 100 μg of antigen were used. The immunostimulator may aid initial antigen uptake and processing.     

Rapid identification of Vibrio anguillarum by Colony hybridization

A 562 base pair fragment of DNA from a serotype A strain of Vibrio anguillarum was cloned into pUC9 and used as a hybridization probe for the rapid identification of Vibrio anguillarum by colony hybridization. The probe was tested on nine different fish pathogens, 15 Vibrio isolates, 2 organisms closely related to Vibrio, and 9 serotypes of V. anguillarum. The probe hybridized only with the DNA of V. anguillarum serotypes A and H. The sequence of the 562 nucleotides have been determined. This probe allows rapid, reliable, and specific detection of V. anguillarum in freshwater ayu, Plecoglossus altivelis.     

Peroxidation of lipids and growth inhibition induced by UV-B irradiation

Cotyledons excised from dark-grown seedlings of cucumber (Cucumis sativus L.) were cultured in vitro under UV radiation at different wavelengths, obtained by passage of light through cut-off filters with different transmittance properties. Growth and the synthesis of chlorophyll (Chl) in cotyledons were inhibited and malondialdehyde was accumulated upon irradiation at wavelengths below 320 nm. Exogenous application of scavengers of free radicals reversed the growth inhibition induced by UV-B. Measurement of the fluorescence of Chl a suggested that electron transfer in photosystems was affected by UV-B irradiation. On the basis of these results, the involvement is postulated of active species of oxygen in damages to thylakoid membranes and the growth inhibition that are induced by UV-B irradiation.Abbreviations Chl chlorophyll - F_m maximal fluorescence (dark) - F_m maximal fluorescence (light) - F_v variable fluorescence (dark) - F_v variable fluorescence (light) - MDA malondialdehyde - O₂ Superoxide radical - PS photosystem - q_N non-photochemical quenching of fluorescence - q_P photochemical quenching of fluorescence - UV-B_BE biologically effective UV-B radiation - WL(T = 0.5) wavelength at which 50% transmittance occurs     

Characterization of acrolein-induced protein cross-links

Lipid peroxidation products contribute to protein aggregation that occurs during oxidative stress in a number of degenerative disorders. Acrolein (ACR), a highly toxic lipid peroxidation aldehyde, is a strong cross-linking agent of cellular components such as proteins. To understand the mechanisms of oxidative stress-induced protein aggregation, this study characterized the ACR modification of chain B from bovine insulin by mass spectrometry. To identify the cross-linking sites, the ACR-treated peptide was digested with a protease and the resulting peptides were analysed by liquid chromatography-tandem mass spectrometry. Inter- and intra-molecular cross-linking adducts were identified between amino groups and the side chain of histidine in the peptide. These results indicated that the ACR-induced cross-links were accompanied by two reactions, namely Michael addition and Schiff base formation. In conclusion, the use of mass spectrometric techniques provided chemical evidence for protein cross-linking with ACR.     

Increase of salt dependence of halophilic nucleoside diphosphate kinase caused by a single amino acid substitution

Nucleoside diphosphate kinase (HsNDK) from an extremely halophilic archaea, Halobacterium salinarum, is composed of a homo hexamer, assembled as a trimer of basic dimeric units. It requires >2 M NaCl for refolding, although it does not require NaCl for stability or enzymatic activity below 30 °C. A HisN111L mutant with an N-terminal extension sequence containing hexa-His tag, in which Asn111 was replaced with Leu, was designed to be less stable between basic dimeric units. This mutant can lose between 6 and 12 hydrogen bonds between basic dimeric units in the hexamer structure. The HisN111L mutant had enhanced salt requirements for enzymatic activity and refolding even though the secondary structure of the HisN111L mutant was confirmed to be similar to the control, HisNDK, in low and high salt solutions using circular dichroism. We reported previously that G114R and D148C mutants, which had enhanced interactions between basic dimeric units, showed facilitated refolding and stabilization in low salt solution. The results of this study help to elucidate the process for engineering industrial enzymes by controlling subunit–subunit interactions through mutations.     

Homostachydrine is a Xenobiotic Substrate of OCTN1/SLC22A4 and Potentially Sensitizes Pentylenetetrazole-Induced Seizures in Mice

Neurochemical Research - Understanding of the underlying mechanism of epilepsy is desired since some patients fail to control their seizures. The carnitine/organic cation transporter OCTN1/SLC22A4...     

A novel,potent, and orally active VLA-4 antagonist with good aqueous solubility: trans-4-[1-[[2-(5-Fluoro-2-methylphenylamino)-7-fluoro-6-benzoxazolyl]acetyl]-(5S)-[methoxy(methyl)amino]methyl-(2S)-pyrrolidinylmethoxy]cyclohexanecarboxylic acid

We have carried out the optimization of substituents at the C-3 or the C-5 position on the pyrrolidine ring of VLA-4 antagonist 3 with 2-(phenylamino)-7-fluorobenzoxazolyl moiety for the purpose of improving in vivo efficacy while maintaining good aqueous solubility. As a result, we successfully increased in vitro activity in the presence of 3% human serum albumin and achieved an exquisite lipophilic and hydrophilic balance of compounds suitable for oral administrative regimen. The modification resulted in the identification of zwitterionic compound 7n with (5S)-[methoxy(methyl)amino]methylpyrrolidine, which significantly alleviated bronchial hyper-responsiveness to acetylcholine chloride at 12.5 mg/kg, p.o. in a murine asthma model and showed favorable aqueous solubility (JP1, 89 μg/mL; JP2, 462 μg/mL). Furthermore, this compound showed good oral bioavailability (F = 54%) in monkeys.     

Isolation and Constitution of a Xylan from Bamboo

A xylan from bamboo culm was isolated by extraction with aikali of chlorite holocellulose and fractional precipitation as a copper complex. The structure was investigated by means of examination of acid components by controlled hydrolysis, methylation analysis, and periodate oxidation. As a result, 4-O-methyl-α-D-glucuronic acid and 2-O-(4-O-methyl-α-D-glucopyranosyluronic acid) D-xylose were isolated and identified as acid components of the bamboo xylan. Hydrolysis of the fully methylated products afforded 2,3,5-tri-O- methyl-L-arabinose (1.6 moles), 2,3,4-tri-O-methyl-D-xylose (1.2 moles), 2,3,4,6-tetra-O-methyl-D-glucose(0.4 moles), 2,3-di-O-methyl-D-xylose (35.8 moles) and mono-O-methyl-D-xylose (2.6 moles). In addition to the above methylated sugars, 2,3,4-tri-O-methyl-D-glucuronic acid and partially methylated aldobiouronic acid were separated by cellulose column chromatography and identified. These results suggest that the bamboo xylan consists mainly of a linear backbone of 1,4-linked β-D-xylopyranose unit, to which L-arabinofuranose and 4-O-methyl-D-glucuronic acid were attached as a single side chain unit at C₂ or C₃.

Additional evidence for a linear chain structure has been given by periodate oxidation. On oxidation by periodate, the bamboo xylan consumed 1.09 moles of periodate and produced 0.05 mole of formic acid per anhydroxylose unit.     

An exact test for the association between the disease and alleles at highly polymorphic loci with particular interest in the haplotype analysis

The association analysis between the disease and genetic alleles is one of the simple methods for localizing the susceptibility locus in the genes. For revealing the association, several statistical tests have been proposed without discussing explicitly the alternative hypotheses. We therefore specify two types of alternative hypotheses (i.e., there is only one susceptibility allele in the locus, and there is an extension or shortening of alleles associated with the disease) and derive exact tests for the respective hypotheses. We also propose to combine these two tests when the prior knowledge is not sufficient enough to specify one of these two hypotheses. In particular, these ideas are extended to the haplotype analysis of three-way association between the disease and bivariate allele frequencies at two closely linked loci. As a by-product, a factorization of the probability distribution of the three-way cell frequencies under the null hypothesis of no three-way interaction is obtained.