Quantitative structure—activity relationships of light-dependent herbicidal 4-pyridone-3-carboxanilides I. Effect of benzene ring substituents at the anilide moiety

A number of substituted 4-pyridone-3-carboxanilide derivatives show various degrees of light-dependent herbicidal activity. The effects of substituents at the anilide moiety on the activity against Echinochloa oryzicola were analysed quantitatively with physicochemical substituent parameters. The activity was shown to vary parabolically with total hydrophobicity (Σπ) of the anilide ring substituents as well as with the steric parameter (E_s) of the ortho-substituents. The E_s parameter for only the bulkier ortho-substituent, with the more negative value, but not for the two, was significant. The effect of substituents at the 1-position was expressible by indicator variables assigned to each 1-substituted series, the physicochemical rationalization being left for future analyses.     

The use of micro-beam X-ray diffraction for the characterization of starch crystal structure in rice mutant kernels of waxy, amylose extender, and sugary1

Micro-beam X-ray diffraction analyses were carried out on slices from wild-type rice and mutants. The method permitted the crystalline structure to be analyzed with less destruction of cells and fewer artificial effects that occur during the purification of starch from tissue and provided information concerning the localization and crystalline structure of starches distributed in the endosperm. The starch on kernel slices from the wild-type and waxy mutant, carrying a defect for the Granule-bound starch synthase I (GBSSI) gene, displayed an A-type of diffraction pattern; no difference in the crystalline patterns between starches located in the inner and outer region in a kernel were observed. A double mutant of the waxy and amylose extender (ae) mutant carrying a defect for the Starch branching enzyme IIb gene accumulated amylose-free B-type starches. The kernel slice from the double mutant of waxy and sugary1, mutated on the Isoamylase I locus, displayed an A-type diffraction pattern in the outer region and was amorphous in the inner region. A chain-length distribution analysis of polyglucans in kernels from wild-type and mutants showed that ae amylopectin had more long chains and less short chains than the wild-type and waxy amylopectin. On the other hand, the water-soluble polysaccharide in the inner region of the sugary1 endosperm had more short chains than the amylopectin in the outer region counterparts. These results indicate that branch chain length in amylopectin is crucial in determining the formation of A- and B-type starches.     

Age-related accumulation of persistent organic chemicals in captive king penguins (Aptenodytes patagonicus)

Persistent organic chemicals are non-biodegradable in nature and have a tendency to bioaccumulate in the top organisms of the food chain. We measured persistent organic chemicals, including polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and benzotriazole-based ultraviolet stabilizers (UV-BTs), in the serum of captive king penguins (Aptenodytes patagonicus) using gas chromatography with an electron capture detector and mass spectrometry to examine their age-related accumulation. PCBs, DDE, UV-PS, and UV-9 were detected in the blood of captive king penguins, and the concentrations of total PCBs, DDE, and UV-9 were positively correlated with age. These results suggest that there is a similar age-related accumulation of persistent organic chemicals in marine birds in the wild, and that older individuals are at a higher risk of contamination.     

Greater disruption due to failure of inhibitory control on an ambiguous distractor

Considerable evidence indicates that a stimulus that is subthreshold, and thus consciously invisible, influences brain activity and behavioral performance. However, it is not clear how subthreshold stimuli are processed in the brain. We found that a task-irrelevant subthreshold coherent motion led to a stronger disturbance in task performance than did suprathreshold motion. With the subthreshold motion, activity in the visual cortex measured by functional magnetic resonance imaging was higher, but activity in the lateral prefrontal cortex was lower, than with suprathreshold motion. These results suggest that subthreshold irrelevant signals are not subject to effective inhibitory control.     

Effect of extracts from <Emphasis Type="Italic">narezushi</Emphasis>, a fermented mackerel product,on cholesterol metabolism in Wistar rats

Narezushi extract was separated into peptide and nonpeptide fractions by ion-exchange column chromatography. The narezushi extract and fractions were administered to rats in a diet enriched with lipid and cholesterol for 30 days. In the narezushi extract and nonpeptide fraction groups, increases in triglyceride, total cholesterol, and low-density lipoprotein-cholesterol levels in the plasma and accumulation of total lipids and triglyceride in the liver were suppressed, while both lipid and cholesterol fecal excretion were increased. In the peptide fraction group, these effects were also observed, except for the suppressing effect on liver lipid accumulation. Narezushi extract administration tended to increase fecal bile acids and promoted the activity of cholesterol 7α-hydroxylase, the rate-limiting enzyme in the synthesis of bile acid from cholesterol in the liver. However, the activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme in the cholesterol synthesis system in the liver, decreased due to regulation by the feedback of lipid transportation from diet to the liver. These results suggest that both the increase in cholesterol and bile acid fecal excretion and the promotion of cholesterol 7α-hydroxylase activities are related to the hypocholesterolemic effects of narezushi extract. Amino acids and organic acids, which are abundantly contained in the nonpeptide fraction, seemed to have more intensive hypocholesterolemic effects than peptides existing in the peptide fraction.     

Structure of Fucoidan from Brown Seaweed Turbinaria ornata as Studied by Electrospray Ionization Mass Spectrometry (ESIMS) and Small Angle X-ray Scattering (SAXS) Techniques

The purpose of this study is to elucidate both the chemical and conformational structure of an unfractionated fucoidan extracted from brown seaweed Turbinaria ornata collected at Nha-trang bay, Vietnam. Electrospray ionization mass spectrometry (ESI-MS) was used for determining the chemical structure and small angle X-ray scattering (SAXS) provided conformational of the structure at the molecular level. The results showed that the fucoidan has a sulfate content of 25.6% and is mainly composed of fucose and galactose residues (Fuc:Gal ≈ 3:1). ESIMS analysis suggested that the fucoidan has a backbone of 3-linked α-l-Fucp residues with branches, →4)-Galp(1→ at C-4 of the fucan chain. Sulfate groups are attached mostly at C-2 and sometimes at C-4 of both fucose and galactose residues. A molecular model of the fucoidan was built based on obtained chemical structure and scattering curves estimated from molecular model and observed SAXS measurement were fitted. The results indicated that fucoidan under study has a rod-like bulky chain conformation.     

Neurohormonal and metabolic effects of medetomidine compared with xylazine in healthy cats

The purpose of this study was to investigate and compare the effects of medetomidine and xylazine on some neurohormonal and metabolic variables in healthy cats. Five cats were used repeatedly in each of 11 groups, which were injected intramuscularly with physiological saline solution (control), 20, 40, 80, 160, and 320 microg/kg of medetomidine, and 0.5, 1, 2, 4, and 8 mg/kg of xylazine. Blood samples were taken over 24 h from the jugular vein for determination of plasma glucose, insulin, cortisol, epinephrine, norepinephrine, glucagon, and nonesterified fatty acid concentrations. Both medetomidine and xylazine induced remarkable hyperglycemia that was dose-dependent except for the response to medetomidine from 0 to 3 h. Both agents suppressed epinephrine and norepinephrine release but not in a dose-dependent manner at the tested dosages. Both agents inhibited insulin release and lipolysis, with similar potency, and tended to suppress cortisol release. The glucagon levels did not change significantly in any of the groups. These results suggest that the effects of medetomidine and xylazine on glucose metabolism and catecholamine release may not be due only to the actions mediated by alpha2-adrenoceptors.     

Changes in circulating adiponectin and metabolic hormone concentrations during periparturient and lactation periods in Holstein dairy cows

Although our previous report demonstrated that adiponectin and AdipoR1 gene expressions changed among different lactation stages in the bovine mammary gland, its in vivo kinetics remain unclear in ruminant animals. In this study, we investigated the changes in circulating concentrations of adiponectin, as well as other metabolic hormones and metabolites, (i) during the periparturient period and (ii) among different lactation stages, in Holstein dairy cows. In experiment 1, serum adiponectin concentrations increased after parturition. Serum insulin concentrations were lower in the postpartum than prepartum period, whereas serum growth hormone (GH) concentrations increased in the postpartum period. Serum nonesterified fatty acids (NEFA) levels were increased during the postpartum period and were dependent on the parity. In experiment 2, there was no significant difference in plasma adiponectin concentrations among lactational stages. Plasma insulin concentrations tended to be lower in early lactation while plasma GH levels tended to be higher. Plasma NEFA concentrations were significantly lower in mid‐ and late‐lactation stages than non‐lactation stages. These findings indicate that elevation of serum adiponectin might be involved in energy metabolism just around parturition, and might exert its action through regulation of receptor expression levels in target tissues in each lactational stage in Holstein dairy cows.