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941.
The design and synthesis of a novel class of 7-azaspiro[3.5]nonane GPR119 agonists are described. In this series, optimization of the right piperidine N-capping group (R2) and the left aryl group (R3) led to the identification of compound 54g as a potent GPR119 agonist. Compound 54g showed a desirable PK profile in Sprague-Dawley (SD) rats and a favorable glucose lowering effect in diabetic rats.  相似文献   
942.
Summary Immunoreactivity of substance P, calcitonin gene-related peptide, vasoactive intestinal polypeptide, neuropeptide Y, and galanin is localized in nerve fibres distributed in the fungiform and filiform papillae of the tongue of the bullfrog,Rana catesbeiana. A combination of indirect double immunofluorescence labelling and a multiple dye filter system clearly demonstrated that all substance P fibres in the connective tissue core of the fungiform and filiform papillae, and within the rim of ciliated cells located on the top of the fungiform papillae showed coexistence with calcitonin gene-related peptide. A few fibres in the epithelial discs, which are located in the centre of the top of the fungiform papillae, showed the immunoreactivity of calcitonin gene-related peptide alone. There were no substance P fibres which showed coexistence with vasoactive intestinal polypeptide, galanin, and neuropeptide Y. In high magnification images, substance P and vasoactive intestinal polypeptide, and substance P and galanin fibres were recognized as two interwined fibres within the same thin nerve bundle. No immunoreactivity of leucine- and methionine-enkephalins can be detected. These findings suggest that the chemoreceptor function of the bullfrog gustatory organ may be under the control of complicated peptidergic innervation.  相似文献   
943.
The leaves of monocotyledonous plants create a developmental sequence of cells and plastids from the base to the apical portion. We investigated fatty-acid and lipid compositions in successive leaf sections of light- and dark-grown wheat (Triticum aestivum L. cv. Chihoku) seedlings. The most notable change in the fatty acid composition was the increase of linolenic acid (18:3) with maturation of leaf cells, which occurred both in light- and dark-grown leaf tissues. In light-grown leaves, the increase of 18:3 with maturation was mainly attributed to the increase of monogalactosyldiacylglycerol (MGD) and also to the increase of the 18:3 level of MGD. In dark-grown leaves, the increase of 18:3 in the leaf apex was caused by the increase of the levels of MGD and digalactosyldiacylglycerol (DGD) and also by the increase of the 18:3 levels of within these two lipids. Since MGD and DGD are mainly found in plastid membranes, these findings indicate that both the synthesis of galactolipids and the formation of 18:3 these lipids take place during plastid development. The plastid ω-3 fatty acid desaturase is responsible for the formation of 18:3 in plastid membrane lipids. To investigate the regulation of desaturation, we isolated a gene for wheat plastid ω-3 fatty acid desaturase (TaFAD7). The mRNA level of TaFAD7 in light-grown leaves was much higher than that in dark-grown leaves. During the greening of etiolated leaves the level of TaFAD7 mRNA increased significantly, accompanied by an increase of the 18:3 level of total fatty acids. On the other hand, the levels of TaFAD7 mRNA were almost the same in all the leaf sections of both light- and dark-grown leaf tissues. These results suggest that the effect of the expression of the TaFAD7 gene on the increase of the 18:3 level is different between the leaf development under continuous light- or dark-conditions and the light-induced greening process of etiolated leaves. The increase of 18:3 content of MGD (or MGD and DGD) with maturation is apparently regulated not solely by the level of TaFAD7 mRNA.  相似文献   
944.
Summary The outer tangential wall (OTW) of epidermal cells of azuki bean epicotyls has a crossed polylamellate structure, in which lamellae of longitudinal cellulose microfibrils alternate with lamellae of transverse cellulose microfibrils. This implies that the cyclic reorientation of cortical microtubules (MTs) from longitudinal to transverse and from transverse to longitudinal occurs on the OTW. Treatment with a solution that contained no auxin caused the accumulation of cells with longitudinal MTs, suggesting that auxin is required for the reorientation of MTs from longitudinal to transverse during the reorientation cycle. Treatment with 6-dimethylaminopurine (DMAP), an inhibitor of protein kinases that promoted the reorientation of MTs from transverse to longitudinal, resulted in the accumulation of cells with longitudinal MTs. Subsequent treatment with auxin caused a marked increase in the percentage of cells with transverse MTs and then a decrease in the percentage, indicating that the reorientation of MTs from longitudinal to transverse and then from transverse to longitudinal occurred during treatment with auxin. The percentage of cells with transverse MTs decreased more slowly in segments that had been pretreated with gibberellin A3 (GA) than in segments that had been pretreated without GA, suggesting that GA, in cooperation with auxin, caused the suppression of the reorientation of MTs from transverse to longitudinal.Abbreviations BL brassinolide - BSA bovine serum albumin - GA gibberellin A3 - DMAP 6-dimethylaminopurine - DMSO dimethylsulfoxide - FITC fluorescein isothiocyanate - IAA indoleacetic acid - MT microtubule - OTW outer tangential wall - PBS phosphate-buffered saline Dedicated to Professor Eldon H. Newcomb in recognition of his contributions to cell biology  相似文献   
945.
The relationship between the development ofCoccinella septempunctata brucki Mulsant (Coleoptera: Coccinellidae) and its parasitoid,Perilitus coccinellae (Schrank) (Hymenoptera: Braconidae) was studied at two photoperiods (L 16:D8 and L 12: D12) at 26°C. The development ofP. coccinellae is well synchronized with the physiological state of the host,C. septempunctata, which can be parasitized not only as adult but also as larva or pupa. The parasitoid larva completed larval development within 19 days in a non-diapausing host, while in diapausing adults as well as in pupae held at diapause-averting conditions, the parasitoid larva ceased growth at the first instar. Growth was resumed when diapause of the host terminated or by the emergence of the adult host from the pupa. About 550 spheric cells, teratocytes, were liberated into the host hemocoel when the parasitoid egg hatched. The teratocytes increased in size in the active host, while their development was arrested in the diapausing host. Application of methoprene caused diapause termination of both host and parasitoid larva. The results indicate that the development of the larva ofP. coccinellae depends on the physiological conditions of the host,C. septempunctata brucki. The host-parasite relation thus represents an ‘endogenous synchronization’ in the sense of Schoonhoven's definition.  相似文献   
946.
The gene locus of Machado-Joseph disease (MJD) has recently been mapped within a 29-cM subregion of 14q chromosome. We did a linkage study of 24 multigenerational MJD Japanese pedigrees, in an attempt to narrow the candidate region of this gene. Pairwise and multipoint linkage analysis, together with haplotype segregation analysis, led to the conclusion that the MJD gene is located at the 6.8-cM interval between D14S256 and D14S81 (Zmax = 24.78, multipoint linkage analysis). D14S291 and D14S280, located at the center of this interval, showed no obligate recombination with the MJD gene (Zmax = 5.93 for D14S291 and 9.99 for D14S280). A weak, but significant, linkage disequilibrium of MJD gene was noted with D14S81 (P < .05) but not with D14S291 or D14S280. These results suggest that a 3.6-cM interval flanked by D14S291/D14S280 and D14S81 is the most likely location of the MJD gene and that it is closest to D14S81.  相似文献   
947.
As they respond to numerous extracellular and intracellularstimuli, plants develop various morphological features and thecapacity for a large variety of physiological processes duringtheir growth. If we are to understand the molecular basis ofsuch developments, we must elucidate the way in which signalsgenerated by such stimuli can be transduced into plant cellsand transmitted by cellular components to induce the appropriateterminal events. In yeast and animal systems, signal pathwaysthat are known collectively as MAPK (mitogen-activated proteinkinase) cascades have been shown to play a central role in thetransmission of various signals. The components of these pathwaysinclude the MAPK family, the activator kinases of the MAPK family(the MAPKK family) and the activator kinases of the MAPKK family(the MAPKKK family). The members of each respective family arestructurally conserved and signals are transmitted by similarphosphotransfer reactions at corresponding steps that are mediatedby a specific member of each family in turn. Both cDNAs andgenes that encode putative homologues of these components haverecently been isolated from plant sources. Some of them havebeen shown to be related not only structurally but also functionallyto members of the MAPK cascades of other organisms. These findingssuggest that plants have signal pathways that are analogousto the MAPK cascades in yeast and animal cells but it remainsto be proven that plant homologues do in fact constitute kinasecascades. Given the presence of so many homologues of MAPKsand MAPKKKs in a single plant species, namely, Arabidopsis thaliana,we can be fairly confident that the putative MAPK cascades areinvolved in various physiological processes in plants. (Received March 28, 1995; )  相似文献   
948.
949.
Intratumoral growth of Staphylococcus aureus Cowan I-derived AP332 was examined by subcutaneous inoculation of cocci in doses ranging from 18 to 1.8 × 105 CFU with Ehrlich ascites tumor cells. Inoculation of 18 CFU AP332 resulted in staphylococcal growth in one of five mice, and the proportion of mice established intratumoral infection increased with the initial inocula. Six other strains of S. aureus also grew in the tumor tissue, and none of the three strains of coagulase-negative staphylococci grew at all. Ethanol-killed tumor cells did not promote staphylococcal growth as vigorously as the live tumor cells, especially when the initial inoculum of AP332 was smaller than 104 CFU.  相似文献   
950.
A novel fibrinogenolytic protease was purified from Bacteroides fragilis strain YCH46. The protease was extracted from cells by ultrasonic treatment and was purified 425-fold with a recovery of 2.1% by sequential procedures using azocasein as a substrate. The purified protease showed a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an estimated molecular weight of 100 kDa, which was consistent with the value obtained by gel filtration, indicating a monomeric native structure. Its optimal pH, Km, and Vmax for azocasein were 7.5, 0.2%, and 286 U/min/mg, respectively. The protease activity was completely inhibited by addition of 1 mM Hg2+, Cu2+, Zn2+, diisopropyl fluorophosphate, N-ethylmaleimide or p-chloromercuribenzoate but not by the inhibitors of metalloprotease or aspartic protease, suggesting that the enzyme is a serine-thiol-like protease. The protease hydrolyzed azocasein, casein, fibrinogen, gelatin, and azocoll, but not bovine serum albumin, ovalbumin, fibrin, fibronectin, immunoglobulins, transferrin, hemoglobin or types I, III, and IV collagen. The enzyme also hydrolyzed the chromogenic substrates alanyl-alanine p-nitroanilide, L -valyl-alanine p-nitroanilide, alanyl-alanyl-valyl-alanine p-nitroanilide, and glycyl-proline p-nitroanilide, but was inert toward L -alanine p-nitroanilide, alanyl-alanyl-alanine p-nitroanilide, and N-α-benzoyl-DL -arginine p-nitroanilide. The protease completely hydrolyzed the α-chain of fibrinogen at 37 C within 10 hr and at the same time the time required for clotting of protease-treated fibrinogen by thrombin was prolonged. The fibrinogenolytic activity of a crude extract of B. fragilis was stronger than that of other species of the Bacteroides fragilis group tested: B. ovatus, B. distasonis, B. eggerthii, B. uniformis, and B. thetaiotaomicron. These results suggest that the fibrinogenolytic protease is an important biological factor in Bacteroides infection.  相似文献   
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