Characterization of extracellular glucoamylase from the ectomycorrhizal mushroom <Emphasis Type="Italic">Lyophyllum shimeji</Emphasis>

To investigate the function of amylases in the fruit-body formation of an ectomycorrhizal fungus, Lyophyllum shimeji, we purified the extracellular amylase in the medium of this fungus. The purified enzyme was obtained from 1.7l stationary culture filtrate, with 4.2% recovery, and showed a single protein band on SDS-PAGE. The molecular mass was about 25kDa. The enzyme was most active at around 40°C and pH 5.0 and stable over pH 4.5–6.5 for 30min at 37°C. This amylase was remarkably activated by the presence of Ca²⁺ ion (7.7 times that of the control), but Ba²⁺ and Ag⁺ completely inhibited the activity. The amylase readily hydrolyzed the -1,4 glucosidic linkage such as dextrin and amylose A (MW, 2900), converting into glucose, and hydrolyzed the -1,6 glucosidic linkage of isomaltohexaose and amylopectin. However, the enzyme did not hydrolyze the cyclic polysaccharides. On the other hand, when a low molecular mass amylose A was hydrolyzed by this amylase, -anomer glucose was produced. From these results, we concluded that the amylase from L. shimeji seems to be a glucoamylase.     

Effect of cyanocobalamin and p-toluic acid on the fatty acid composition of Schizochytrium limacinum (Thraustochytriaceae, Labyrinthulomycota)

Changes in the fatty acid composition of docosahexaenoic acid (DHA)-producing Schizochytrium limacinum SR21 were investigated. The addition of cyanocobalamin, which is an active component of vitamin B₁₂, decreased the content of odd-chain fatty acids such as pentadecanoic acid (C15:0) and heptadecanoic acid (C17:0). Cyanocobalamin may upregulate the cobalamin-dependent methylmalonyl-CoA mutase, which converts propionic acid to succinic acid, thereby decreasing the content of odd-chain fatty acids. The addition of p-toluic acid resulted in a decrease in docosapentaenoic acid (DPA, 22:5n-6) content and an increase in eicosapentaenoic acid (EPA, 20:5n-3) content in a dose-dependent manner. Two additional peaks of fatty acids, characterized as Δ4,7,10,14-eicosatetraenoic acid (20:4n-7) and Δ4,7,10,14-docosatetraenoic acid (22:4n-9), were detected.     

Inhibitory effects of capsaicinoids on fatty acid desaturation in a rat liver cell line

The inhibitory effects of such vanillylamides as capsaicin and nine capsaicinoids on fatty acid desaturation in liver cells were investigated by using the cultured rat liver cell line, BRL-3A. When capsaicin was added to the medium, it had a relatively strong inhibitory effect on delta6 desaturation and clear inhibitory effects on delta5 and C24delta16 desaturation (delta16 desaturation of C24-polyunsaturated fatty acids). Capsaicinoids with side carbon chain lengths of C10:0 and C12:0 expressed the maximum inhibitory effects of the nine capsaicinoids on fatty acid desaturation in the BRL-3A cells. The inhibitory effects of the capsaicinoids were not correlated with their pungency.     

Homozygous CYP2B6 *6 (Q172H and K262R) correlates with high plasma efavirenz concentrations in HIV-1 patients treated with standard efavirenz-containing regimens

Efavirenz (EFV) is metabolized by cytochrome P450 2B6 (CYP2B6) in the liver. We analyzed the genotypes of CYP2B6 and their contribution to plasma EFV concentrations in 35 EFV-treated patients in International Medical Center of Japan. The mean plasma EFV concentration of patients with CYP2B6 *6/*6 (Q172H and K262R) (25.4+/-7.5 microM, +/-SD, n = 2) was significantly higher than that of patients with genotypes *6 heterozygote (9.9+/-3.3 microM, n = 10) or without alleles *6 (8.0+/-2.6 microM, n = 23) (p < 0.0001). To confirm our result, we further analyzed nine patients (three with high EFV concentrations and arbitrarily selected six with normal EFV concentrations) treated in Osaka National Hospital, and it resulted that the only three patients with the high concentrations were the *6/*6 holder. EFV dose could be decreased in those patients harboring the genotype to reduce toxicity with compromising potency, representing the first step of the Tailor-Made therapy of HIV-1 infection.     

Microbial hydroxylation of indole to 7-hydroxyindole by Acinetobacter calcoaceticus strain 4-1-5

A screening study yielded Acinetobacter calcoaceticus strain 4-1-5, which is capable of hydroxylating indole to 7-hydroxyindole. Strain 4-1-5 grew on terephthalate as the sole source of carbon and energy and hydroxylated indole to 7-hydroxyindole by cometabolism of indole using terephthalate as cosubstrate. Strain 4-1-5 produced 0.574 mM of 7-hydroxyindole at 2.38 mM indole in 24 h with the cell growth.     

Zoonotic onchocerciasis caused by a parasite from wild boar in Oita, Japan. A comprehensive analysis of morphological characteristics of the worms for its diagnosis

Histological examination of a nodule removed from the back of the hand of a 58-year-old woman from Oita, Kyushu, Japan showed an Onchocerca female sectioned through the posterior region of the worm (ovaries identifiable) and young (thin cuticle). Six Onchocerca species are enzootic in that area: O. gutturosa and O. lienalis in cattle, O. suzukii in serows (Capricornis crispus), O. skrjabini and an Onchocerca sp. in Cervus nippon nippon, and O. dewittei japonica in wild boar (Sus scrofa leucomystax). Diagnostic characters of female Onchocerca species, such as the cuticle and its ridges, change along the body length. Tables of the histologic morphology of the mid- and posterior body-regions of the local species are presented. In addition, it was observed that transverse ridges arose and thickened during the adult stage (examination of fourth stage and juvenile females of O. volvulus). The specimen described in this report, with its prominent and widely spaced ridges, was identified as O. d. japonica. Four of the 10 zoonotic cases of onchocerciasis reported worldwide were from Oita, three of them being caused by O. d. japonica, the prevalence of which in local wild boar was 22 of 24 (92%).     

Sex differences in the pharmacokinetics of pioglitazone in rats

Clinical studies have suggested that pioglitazone, an insulin sensitizer, has a stronger effect in women than in men. To determine the sex difference in the pharmacokinetics of pioglitazone, we examined the plasma and white adipose tissue levels of pioglitazone and its active metabolites (M-II, M-III and M-IV) in male and female rats treated with a single or repeated oral administration of pioglitazone (10 mg/kg). The AUCs of pioglitazone (149.6+/-22.6 vs. 103.3+/-14.0 microg.h/ml; P<0.01), M-III (31.4+/-8.1 vs. 20.2+/-4.7 microg.h/ml; P<0.05) and M-IV (41.9+/-15.5 vs. 14.1+/-1.6 microg.h/ml; P<0.01) were larger in female rats than in male rats, but the levels of M-II were similar. Any of the compounds did not accumulate in plasma after repeated administration. According to kinetic model analysis, the apparent elimination rate of pioglitazone and the formation rate of M-II were faster in male rats than in female rats. No significant sex difference was found in the tissue-to-plasma concentration ratios of pioglitazone or its active metabolites in white adipose tissue. These results suggest that there are sex differences in the plasma levels of pioglitazone and some of its active metabolites and that those differences are reflected in differences in white adipose tissue levels.     

C19 odd-chain polyunsaturated fatty acids (PUfas) are metabolized to C21-PUfas in a rat liver cell line, and curcumin, gallic acid, and their related compounds inhibit their desaturation

It was demonstrated that the rat liver cell line BRL-3A converted exogenous C19 odd chain-polyunsaturated fatty acids (PUFAs) into the corresponding C21- and C23-PUFAs as follows: 21:3n-8, 21:4n-8, 23:3n-8, and 23:4n-8 (from 19:3n-8); 21:4n-5, 21:5n-5, 23:4n-5, and 23:5n-5 (from 19:4n-5); 21:5n-2, 21:6n-2, 23:5n-2, and 23:6n-2 (from 19:5n-2). It presumed that these C19 PUFAs were converted through the mimic route to docosahexaenoic acid (22:6n-3) from eicosapentaenoic acid (20:5n-3). In addition, the characterization of the change of fatty acid composition of cellular lipids in rat liver cells were examined, using 19:4n-5 and several fatty acid desaturation inhibitors. Curcumin related compounds, curcumin, capsaicin, isoeugenol, 4-(4-hydroxy-3-methoxyphenyl)-3-buten-2-one, and gallic acid esters with near five carbon numbered alcohol had great changes of fatty acid composition of cellular lipids based on inhibition of the A6 desaturation of C24-PUFAs in rat liver cells.     

Synthesis of silicon-containing azole derivatives with magnesium bromide diethyl etherate,and an investigation of their fungicidal activities

Enhancement of magnesium bromide diethyl etherate in addition reaction of trimethylsilylmethylmagnesium chloride 5 to 2-(1H-1,2,4-triazol-1-yl)acetophenones 6 allowed us to prepare silicon-containing azole derivatives, which were tested for fungicidal activity and phytotoxicity. Among them, 2-(4-fluorophenyl)-1-(1H-1,2,4-triazol-1-yl)-3-trimethylsilylpropan-2-ol 1a was determined to be the most effective and potential candidate for novel fungicide.     

Selective foraging on terrestrial invertebrates by rainbow trout in a forested headwater stream in northern Japan

The important contribution of terrestrial invertebrates to the energy budget of drift-foraging fishes has been well documented in many forested headwater streams. However, relatively little attention has been focused on the behavioral mechanisms behind such intensive exploitation. We tested for the hypothesis that active prey selection by fishes would be an important determinant of terrestrial invertebrates contribution to fish diets in a forested headwater stream in northern Japan. Rainbow trout, Oncorhynchus mykiss, were estimated to consume 57.12 mg m^–2 day^–1 (dry mass) terrestrial invertebrates, 77% of their total input (73.89 mg m^–2 day^–1), there being high selectivity for the former from stream drift. Both the falling input and drift of terrestrial invertebrates peaked at around dusk, decreasing dramatically toward midnight. In contrast, both aquatic insect adults and benthic invertebrates showed pronounced nocturnal drift. Because the prey consumption rates of rainbow trout were high at dawn and dusk, decreasing around midnight, the greater contribution of terrestrial invertebrates to trout diet was regarded as being partly influenced by the difference in diel periodicity of availability among prey categories. In addition, selectivity also depended upon differences in individual prey size among aquatic insect adults, and benthic and terrestrial invertebrates, the last category being largest in both the stream drift and the trout diets. We concluded that differences in both the timing of supplies and prey size among the three prey categories were the primary factors behind the selective foraging on terrestrial invertebrates by rainbow trout.