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991.
992.
993.
Two distinct electroantennographycally active (EAG-active) components, A and B, and a weakly active component C were found in a solvent extract from virgin females of the Ishigaki strain of the tussock moth, Orgyia postica (Walker). Components A, B, and C were found in the extract of the females at 4.0, 0.5, and 4.0 ng/female respectively. Components A, B, and C were identified as (6Z,9Z,11S,12S)-11,12-epoxyhenicosa-6,9-diene [(11S,12S)-1: posticlure], (6Z)-henicos-6-en-11-one (2), and (6Z,9Z)-henicosa-6,9-diene (3), respectively. Component B was absent in the extract from the Okinawa strain, in which components A and C were present at 2.0 and 1.5 ng/female respectively. (11S,12S)-1 and the racemic mixture showed attractiveness for both the Okinawa and Ishigaki strains, whereas (11R,12R)-1 did not. The addition of 2 significantly reduced the trap catches with (11S,12S)-1 on the Okinawa strain which lacked 2, while there was no significant inhibitory effect on the Ishigaki strain. The addition of 3 to (11S,12S)-1 did not significantly affect trap catches at Ishigaki or Okinawa. This confirmed that the attractant pheromone of O. postica of the Ishigaki strain is also (11S,12S)-1.  相似文献   
994.
The effects of adenine and (or) guanosine concentration on the accumulation of inosine, xanthosine, adenosine and succino-adenosine were studied with various purine auxotrophs of Bacillus subtilis K strain. Genetical derepression of the common pathway enzymes resulted in increase in the accumulation of inosine, xanthosine and adenosine. Co-operative repression system of a common pathway enzyme, succino-AMP lyase with respect to adenine and guanosine, was confirmed under the condition of the accumulation test. From these and the relating other studies it was concluded that the synthesis of AMP was regulated mainly by the inhibition of PRPP amidotransferase by AMP and secondly by the repression of the common pathway enzymes by adenine and guanosine, that the synthesis of GMP was regulated mainly by the inhibition and repression of IMP dehydrogenase by guanine derivatives and that GMP was synthesized in preference to AMP at the branch point, IMP.  相似文献   
995.
Toluene is widely used as an organic solvent in various industries and commercial products. Recent investigations have shown that toluene may induce male reproductive dysfunctions and carcinogenicity. To clarify whether the toxicity results from the interference of endocrine systems or direct damage to reproductive organs, we examined the effects of toluene on the male reproductive system in rats, comparing to those of diethylstilbestrol (DES), a potent synthetic estrogen. Toluene (50, 500 mg/kg) or DES (2 mg/kg) injected subcutaneously to male Sprague-Dawley rats once a day for 10 days decreased the epididymal sperm counts and the serum concentrations of testosterone. The mRNA level for gonadotropin-releasing hormone receptor in the pituitary was decreased by DES, but not by toluene. On the contrary, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation in testes, the biological marker for oxidative DNA damage, was increased by toluene but not by DES. These results suggest that toluene induces reproductive toxicity via direct oxidative damage of spermatozoa, whereas DES affects endocrine systems via the hypothalamo-pituitary-gonadal axis. Morphological findings supported the idea. To determine the mechanism of 8-oxodG formation in vivo , we examined DNA damage induced by toluene metabolic products in vitro . Minor toluene metabolites, methylhydroquinone and methylcatechols, induced oxidative DNA damage, and the methylcatechols induced NADH-mediated 8-oxodG formation more efficiently than methylhydroquinone did. We propose that oxidative DNA damage in the testis plays a role in reproductive toxicity induced by toluene.  相似文献   
996.
High activity alkaline protease was obtained when the enzyme was immobilized on Dowex MWA-1 (mesh 20–50) with 10% glutaraldehyde in chilled phosphate buffer (M/15, pH 6.5). Activity yields of the protease and rennet were 27 and 29, respectively. The highest activities appeared at 60°C, pH 10 for alkaline protease and 50°C, pH 4.0 for rennet. The properties of both proteases were not essentially changed by the immobilization except that the Km values of both enzymes were increased about tenfold as a result of immobilization. Both proteases in the immobilized state were more stable than those in the free state at 60°C. Other peptide hydrolases, β-galactosidase, invertase, and glucoamylase, were successfully immobilized with high activities, but lipase, hexokinase, glucose-6-phosphate dehydrogenase, and xanthine oxidase became inactive.  相似文献   
997.
The stelar morphology of adult and/or juvenile plants of 24 species of Aspleniaceae was examined. A radial dictyostele with two leaf-traces and a single root-trace at each leaf-gap is the most common type in the Aspleniaceae, whereas dorsiventral dictyosteles are present inAsplenium sect. Hymenasplenium andA. lepturus. The dorsiventral steles differ among species with regard to ontogenetical changes and root characteristics. Peculiar stelar structures are described forA. griffithianum andDiplora d'urvillaei. The typical single root-trace often divides to give rise to several or many branchlets in the hypodermal layer of the lowermost part of the petiole. A bud occasionally forms at the abaxial base of the stipe and is supplied by the bud-trace which actually departs from the point of divergence of the root-trace branchlets. A solenostelic bud-trace was observed inA. lepturus.  相似文献   
998.
Two new species of the sciaenid genusNibea are described;N. squamosa from northern Australia and Papua New Guinea andN. microgenys from northern Australia. Both species differ from all known congeners in having a small, inferior mouth, with the lower jaw teeth uniform in size.N. squamosa is distinguished fromN. microgenys by a higher number of lateral line scales (57–60 vs. 48–50), the last pleural rib on the 11th vertebra (vs. 10th), and a longer and more slender caudal peduncle (length 25.9–30.4%SL, depth 6.3–7.9% SL vs. 21.5–26.3, 8.0–10.3).N. squamosa exhibits hyperostosis in some elements, such as the frontals and dorsal and anal pterygiophores.  相似文献   
999.
Mammalian oocytes contain the histone H1foo, a distinct member with low sequence similarity to other members in the H1 histone family. Oocyte-specific H1foo exists until the second embryonic cell stage. H1foo is essential for oocyte maturation in mice; however, the molecular function of this H1 subtype is unclear. To explore the function of H1foo, we generated embryonic stem (ES) cells ectopically expressing H1foo fused to an EGFP (H1foo-ES). Interestingly, ectopic expression of H1foo prevented normal differentiation into embryoid bodies (EBs). The EB preparations from H1foo-ES cells maintained the expression of pluripotent marker genes, including Nanog, Myc and Klf9, and prevented the shift of the DNA methylation profile. Because the short hairpin RNA-mediated knockdown of H1foo-EGFP recovered the differentiation ability, H1foo was involved in preventing differentiation. Furthermore, ChIP analysis revealed that H1foo-EGFP bound selectively to a set of hypomethylated genomic loci in H1foo-ES, clearly indicating that these loci were targets of H1foo. Finally, nuclease sensitivity assay suggested that H1foo made these target loci decondensed. We concluded that H1foo has an impact on the genome-wide, locus-specific epigenetic status.  相似文献   
1000.
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