Mutagenic properties of 2-amino-N6-hydroxyadenine in Salmonella and in Chinese hamster lung cells in culture

The mutagenicity of the base analogue, 2-amino-N6-hydroxyadenine (AHA), was tested in Salmonella typhimurium TA100 and TA98 and in Chinese hamster lung (CHL) cells. AHA showed very potent mutagenicity in TA100 without S9 mix, inducing 25,000 revertants/micrograms. The mutagenicity increased about 2-fold upon addition of S9 mix containing 10 microliters S9. AHA was found to be one of the strongest mutagens for TA100. Addition of S9 mix containing 100 microliters S9 induced no significant increase of revertants with AHA at amounts up to 50 ng per plate. AHA was also mutagenic for the frameshift mutant, TA98, without S9 mix, the mutagenicity for TA98 being about 1/1000 of that for TA100. When the mutagenicity of AHA was tested in CHL cells, with diphtheria toxin resistance (DTr) as a selective marker in the absence of S9 mix with a 3-h treatment of cells, DTr mutants increased dose-dependently at concentrations of 2.5-15 micrograms/ml. When cells were incubated with AHA for 24 h, a 200-fold increase in the number of DTr mutants was observed; the mutagenicity was 500-fold higher than that of ethyl methanesulfonate. This marked increase of mutagenicity by prolonged incubation may indicate that AHA induces mutations mainly after incorporation into DNA. The addition of a small amount of S9 increased the mutagenicity obtained with a 3-h treatment 2-fold, but a larger amount of S9 decreased the mutagenicity as was found with S. typhimurium TA100.     

Two new species of the genusAmblyeleotris (Pisces: Gobiidae) from the Ryukyu Islands,Japan

Two new shrimp-associated gobies,Amblyeleotris yanoi sp. nov. andA. masuii sp. nov. are described on the basis of specimens from Iriomote-jima Island and Okinawa-jima Islands, Okinawa Prefecture, Japan.A. yanoi is distinguished from other members of the genus by the combination of the following characters: 14 anal fin soft rays, 19 pectoral fin rays, 97–103 longitudinal scales, a candle flame-shaped marking on the caudal fin, a very low membrane connecting the pelvic fins and absence of a ventral frenum.A. masuii differs from all other congeners by having 92–97 longitudinal scales, the length of the interpelvic connecting membrane relative to the longest pelvic fin ray (0.43–0.66), black blotches on the sides of the chin, and blue spots on the opercle and preopercle.     

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.     

Studies on Biologically Active Substances Formed by Bacilli

The products of several Bacillus strains were investigated on rabbit serum calcium decreasing, oxytocic and toad heart function promoting activities. These products were obtained from the clear supernatant fluid of the culture medium after the cells were removed by centrifugation.

For the production of rabbit serum calcium decreasing substance, Bacillus subtilis K and Bacillus natto No. 8 were found to be usefull, Bacillus megaterium KM, Bacillus cereus var. mycoides and Bacillus subtilis K produced oxytocic principle. Bacillus subtilis K, Bacillus brevis and Bacillus megaterium KM also produced toad heart function promoting factor.

A procedure was developed to obtain the electrophoretically homogenous rabbit serum calcium decreasing substance from culture filtrate of Bacillus subtilis K. The crude substance was obtained as isoelectric precipitate by adjusting the culture filtrate to pH 3.0. The crude substance was purified by gel filtration on a Sephadex G-75 column, isoelectric fractionation and chromatography on DEAE-cellulose column. The purified preparation was shown to be homogenous by Tiselius electrophoresis but was separated into two bands by polyacrylamide electrophoresis. The chemical analysis of this biologically active substance indicated this substance to be a lipoprotein. The substance decreased rabbit serum calcium level about 12% at 6~8hr after intravenous injection (dose; 0.5 mg/kg body weight).     

Compilation of Japanese fisheries statistics for the Japanese eel, <Emphasis Type="Italic">Anguilla japonica</Emphasis>, since 1894: a historical dataset for stock assessment

Fishery sustainability and the extinction risk of the Japanese eel, Anguilla japonica, are of global concern. The landings of the Japanese eel in Japan comprise a large part of the landings in East Asia. This study provides a compiled dataset of the annual fisheries statistics of the Japanese eel in Japan for stock assessment. The Japanese government has been recording Japanese eel statistics annually since 1984 in five series of annual reports by conducting systematic questionnaire surveys of fisheries managers and associations; however, most of these data are stored in analog format. The key variables in the dataset include the harvest weight of eels, the harvest weight and number of seeds for aquaculture, the number of eels stocked, and the number of management entities engaged in the eel fishery. The levels of spatial aggregation of the variables include the site (river and lake), prefecture, inland and coastal waters, and total in Japan. We also incorporated location data (latitude and longitude) of the site and prefecture into the dataset. Eel harvest includes primarily yellow eels (late juvenile stage) and silver eels (mature stage). Seed harvest in inland waters includes glass eels (intermediate stage between leptocephalus and elver) and elvers (early juvenile stage). Seed harvest from coastal waters comprises glass eels. This dataset provides information to assess long-term trends in the Japanese eel population.     

Difference in response by two cyprinid species to predatory threat from the nocturnal catfish Silurus asotus

Response to predators may not be identical between different prey species with different life histories and body sizes, particularly when the threat of predation is not great. To clarify this hypothesis, we introduced two prey species (10 Japanese dace, Tribolodon hakonensis, and 10 pale chub, Zacco platypus) into each experimental pond (in total, 8 ponds×4 trials) in which benthic algae had been allowed to grow. The presence or absence of Far Eastern catfish, Silurus asotus, and a refuge for prey fish was used to produce four treatments. The presence of catfish and/or a refuge did not affect either the feeding behavior or growth rate of Japanese dace. In contrast, when catfish were present and no refuge was available, the incidence of bottom feeding for pale chub greatly decreased. Pale chub growth rate was low when catfish were present and a refuge was available, indicating that pale chub spent more of their time in the refuge and lost opportunities of acquiring food. Japanese dace can reach a threshold size at which the prey are safe from predation, but pale chub cannot, and this may explain the differences in response to predators of the two species.     

Distribution of NADPH-diaphorase-positive ascending interneurones in the crayfish terminal abdominal ganglion

Previous neuropharmacological studies have described the presence of a nitric oxide-cGMP signalling pathway in the crayfish abdominal nervous system. In this study we have analysed the distribution of putative nitric oxide synthase (NOS)-containing ascending interneurones in the crayfish terminal abdominal ganglion using NADPH-diaphorase (NADPHd) histochemistry. Ascending intersegmental interneurones were stained intracellularly using the fluorescent dye Lucifer yellow and the ganglia containing the stained interneurones subsequently processed for NADPHd activity. Fluorescence persisted throughout histochemical processing. These double-labelling experiments showed that 12 of 18 identified ascending interneurones were NADPHd positive. Thus many ascending interneurones that process mechanosensory signals in the terminal ganglion may contain NOS, and are themselves likely sources of NO which is known to modulate their synaptic inputs. Three clear relationships emerged from our analysis between the effects of NO on the synaptic inputs of interneurones, their output properties and their staining for NADPH-diaphorase. First were class 1 interneurones with no local outputs in the terminal ganglion, the NE type interneurones, which had sensory inputs that were enhanced by NO and were NADPHd positive. Second were class 1 interneurones with local and intersegmental output effects that had sensory inputs that were also enhanced by NO but were NADPHd negative. Third were class 2 interneurones with local and intersegmental outputs that had synaptic inputs that were depressed by the action of NO but were NADPHd positive. These results suggest that NO could selectively enhance specific synaptic connections and sensory processing pathways in local circuits.     

Developmental expression of HpNanos, the Hemicentrotus pulcherrimus homologue of nanos

The Hemicentrotus pulcherrimus homologue of nanos (HpNanos), that encodes a protein containing two CCHC zinc finger motifs, was isolated from a gastrula cDNA library. The accumulation of HpNanos mRNA during embryonic development and the spatial expression pattern are reported. Developmental northern blot analysis revealed that HpNanos mRNA markedly accumulated during the blastula stages, and then decreased in abundance at the mesenchyme blastula stage. The second phase of HpNanos mRNA expression occurred during gastrulation, after which the expression returned to a low level. Whole-mount in situ hybridization showed that the HpNanos was exclusively expressed in four to six small micromere-descendant cells at the blastula stage. The expression of HpNanos was restricted to the coelomic pouch, which gives rise to the mesoderm of the ventral surface of the adult rudiment, at the prism stage. These results suggest that HpNanos expression will be instrumental for future analyses of the function of small micromere-descendant cells and of the origin of germ cells during sea urchin development.