Nod2-dependent regulation of innate and adaptive immunity in the intestinal tract

The gene encoding the Nod2 protein is frequently mutated in Crohn's disease (CD) patients, although the physiological function of Nod2 in the intestine remains elusive. Here we show that protective immunity mediated by Nod2 recognition of bacterial muramyl dipeptide is abolished in Nod2-deficient mice. These animals are susceptible to bacterial infection via the oral route but not through intravenous or peritoneal delivery. Nod2 is required for the expression of a subgroup of intestinal anti-microbial peptides, known as cryptdins. The Nod2 protein is thus a critical regulator of bacterial immunity within the intestine, providing a possible mechanism for Nod2 mutations in CD.     

Chromatographic and immunological identification of gonadotropin-releasing hormone in five marine teleosts

Brain extracts from bluefin tuna, Thunnus thynnus, red seabream, Pagrus major, black seabream, Acanthopagrus schlegeli, red spotted grouper, Epinephelus akaara and Japanese flounder, Paralichthys olivaceus, were analyzed by high performance liquid chromatography (HPLC) and specific radioimmunoassays. Immunoreactive material co-eluting from HPLC with salmon gonadotropin-releasing hormone (GnRH) and chicken GnRH-II, respectively, was found in all five species. In addition, a GnRH immunoreactive fraction showing the same HPLC retention time as lamprey GnRH-I was detected in the brain extracts of all species examined when using an unspecific radioimmunoassay which detects several GnRH forms, including lamprey GnRH-I. In the Japanese flounder brain extract, a fourth GnRH immunoreactive fraction was detected with the unspecific radioimmunoassay which did not co-elute with any of the six synthetic GnRH standards used in the present study.     

Improving the accuracy of estimating grain weight by discriminating each grain impact on the yield sensor

This study was aimed at accurately estimating total weight of harvested grain on a combine by simply attaching a small yield sensor in the grain tank and by processing the output of the sensor. The yield sensor was first installed in a grain tank of a 1.2 m-swath Japanese-style (head-feeding or jidatsu) combine, and the weight was estimated from individual impulses received at each rotation of a grain-releasing device i.e. an auger blade. A non-linear relation was assumed between the weight of grain released and the impulse received, and the parameters of the non-linear model were optimized to minimize the sum of squares between the estimated and actual weight of grain accumulated at each run of the combine. A threshold for the output discriminated between actual release and no release of the grain from the auger blade. The appropriate range of the threshold was 4–6 times the root-mean squared output of the sensor without throughput (F _rms ) of grain. The aim was to enhance the accuracy of the estimation of grain weight by disregarding signals that did not relate to the accumulation of grain in the tank. Two methods of calculating the impulses were proposed after the discrimination: “successive addition” and “interval addition”, and two non-linear models of converting impulses into the weight of grain: “odd function model” and “positive function model”. The use of the odd function model with the impulse calculated by the interval addition was the most robust, and root-mean squared relative errors of calibration and validation were both stable and around 2.5 % at a threshold of 5F _rms . In the confirmatory experiment with a larger 1.8 m-swath Japanese-style grain combine equipped with the same sensor, the odd function model with the interval addition achieved root-mean squared relative error of 3.6 % at calibration and 4.4 % at validation at a threshold of 5F _rms .     

Inhibition of p16 tumor suppressor gene expression via promoter hypermethylation in canine lymphoid tumor cells

To investigate the epigenetic regulation of the p16 gene in canine lymphoid tumor cells, its methylation status was examined in four canine lymphoid tumor cell lines. In three canine lymphoid tumor cell lines (CLBL-1, GL-1, and UL-1) with low-level p16 mRNA expression, 20 CpG sites in the promoter region of p16 gene were consistently methylated although all of the CpG sites were not methylated in another cell line (CL-1) and normal lymph node cells. The expression level of p16 mRNA in these three cell lines was restored after cultivation in the presence of a methylation inhibitor, 5-Aza-2′-deoxycitidine, indicating inactivation of p16 gene via hypermethylation. This study revealed the inactivation of p16 gene through hypermethylation of its CpG island in a fraction of canine lymphoid tumor cells.     

Changes in the respiratory quinone profile of a soil treated with pesticides

The effects of the pesticides fenitrothion, chlorothalonil, chloropicrin, linuron, and simazine on the structure of microbial communities in a Nagoya University Farm soil (Typic Palehumult) were assessed for 28 days by monitoring changes in respiratory quinone profiles. Pesticides were applied to the soil at 10 times the recommended rates. Fenitrothion, linuron, and simazine did not significantly affect the total amount of quinones (an indicator of microbial biomass), the diversity of the quinones (an indicator of taxonomic diversity of the microbial community), or the composition of the quinone species (an indicator of community structure). Chlorothalonil decreased the diversity of quinones immediately after application, but no significant effect was observed after 3 days of incubation. The amount and composition of the quinones were not affected by chlorothalonil application. Application of chloropicrin decreased the amount and diversity of the quinones for 28 days. A continuous change in the structure of the microbial community in the chloropicrin-treated soil was documented by the change in the dominant quinone species. No change was observed in the control soil. It was suggested that quinone profile analysis is a potential method to detect the effect of pesticide on a soil microbial community. Less pronounced changes in the quinone profile indicated that changes in the structure of a soil microbial community may be masked by the persistent quinones from killed microorganisms.     

Novel antioxidative metabolites in rat liver with ingested sesamin

Sesamin, a major lignan in sesame oil, is known to have many biological activities, especially protective effects against oxidative damage in the liver. As sesamin itself has no antioxidative properties in vitro, to elucidate the mechanism of its antioxidative effects, the reaction products of sesamin in rat liver homogenate were analyzed. The methylenedioxyphenyl moiety in the structure of sesamin was shown to be changed into a dihydrophenyl (catechol) moiety. The enzymatic reaction products in vitro were identified as (1R,2S,5R,6S)-6-(3,4-dihydroxyphenyl)-2-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3,3,0]octane and (1R,2S,5R,6S)-2,6-bis(3,4-dihydroxyphenyl)-3,7-dioxabicyclo[3,3,0]octane, which showed strong radical scavenging activities; the latter was a novel compound. The same metabolites were found as glucuronic acid and/or sulfic acid conjugates in substantial amounts in rat bile after oral administration of sesamin. It is suggested that sesamin is a prodrug and the metabolites containing the catechol moieties in their structures are responsible for the protective effects of sesamin against oxidative damage in the liver.     

Inhibition of phosphorus sorption to goethite, gibbsite, and kaolin by fresh and decomposed organic matter

The direct effects of dissolved organic matter (DOM) on the sorption of orthophosphate onto gibbsite, goethite, and kaolin were examined using a one-point phosphorus sorption index and the linear Tempkin isotherm model. DOM extracted from fresh and decomposed agricultural residues, as well as model organic and humic acids, were used. Changes in the chemical and sorptive characteristics of the DOM in the absence and presence of added orthophosphate (50 mg l⁻¹) were also determined. For residue-derived materials, DOM sorption to all minerals correlated well with percent hydrophobicity, apparent molecular weight, and phenolic acidity in the absence of added orthophosphate. Sorption of DOM to goethite and gibbsite was significantly decreased in the presence of added P. The correlation coefficient values of percent hydrophobicity, apparent molecular weight, and phenolic acidity to sorption also declined in the presence of added P. Thus, the addition of P substantially lowered fractionation of DOM after sorption to goethite and gibbsite. In contrast, few significant P sorption-induced differences were observed in the kaolin system. According to one-point P sorption results, DOM in the form of Aldrich humic acid, oxalate, and decomposed clover and corn residue, significantly inhibited P sorption to goethite at concentrations of 50 and 200 mg total soluble carbon (C_TS l⁻¹). Phosphorus sorption to gibbsite was significantly inhibited by 50 mg C_TS l⁻¹ derived from decomposed corn residue, fresh dairy manure residue, and oxalate solution. At 200 mg C_TS l⁻¹, all DOM solutions were found to inhibit P sorption to gibbsite. This study suggests that DOM inhibition of P sorption depends on the chemical properties of both the sorbent and the DOM itself. In general, DOM from decomposed organic materials inhibited P sorption to a greater extent than did DOM derived from fresh materials. This stronger inhibition highlights the importance of microbial processes in the release of soluble soil P, a key determinant of P availability to plants.     

Caffeoylsophorose in a red vinegar produced through fermentation with purple sweetpotato

Recently, a new red vinegar has been developed via fermentation with the storage root of purple-fleshed sweetpotato, Ipomoea batatas L. cv. Ayamurasaki. The red vinegar had a higher antioxidative activity than white or black vinegars. The red vinegar contained some new components possibly derived from the original purple sweetpotato. A major component was isolated using preparative HPLC, and the chemical structure was determined to be 6-O-(E)-caffeoyl-(2-O-beta-d-glucopyranosyl)-alpha-d-glucopyranose (caffeoylsophorose) by MS and NMR. Because the caffeoylsophorose showed a high antioxidative activity, it plays an important functional role in red vinegar as do anthocyanins and other components. Examination of the mechanism of formation is now in progress.     

Qualitative investigation on hydrothermal treatment of Hinoki (Chamaecyparis obtusa) bark for production of useful chemicals

Hydrothermal treatment of an outer layer of a bark of Hinoki (Chamaecyparis obtusa) tree was investigated qualitatively for the possibility of utilizing residual forest biomass to produce valuable chemicals. Experiments were carried out in a semibatch reactor apparatus that allows the study of the effect of reaction temperatures in a single run. Gas chromatography-mass spectrometry analyses show the presence of useful chemicals such as furfural, aromatic compounds (1,3-di-tert-butyl benzene and 2,4-di-tert-butyl phenol), and fatty acids (myristic acid, palmitic acid, and stearic acid) in the products.