粘虫棉铃虫对杀虫剂活性的相关性

研究了37种杀虫剂对粘虫、棉铃虫活性的相关性。结果表明,粘虫对杀虫剂的活性和棉铃虫是一致的,其直线回归式：Y＝164．36＋0．646X相关系数（R）为0．953。R值受棉铃虫对拟菊酯抗性的影响。     

Investigation on recombinant hirudin via oral route

The possibility for oral administration of peptide recombinant hirudin variant (rHV2-K47) as an anticoagulant agent was evaluated in several aspects. The proteolytic properties of rHV2-K47 and its stability during storage were examined by in vitro experiments. Radiolabeled rHV2-K47 was infused into the duodenum of rats and rHV2-K47 absorbed into serum was shown to be intact by electrophoresis pattern. The in vivo coagulation time of blood from mouse was prolonged significantly after oral administration of rHV2-K47. The bioavailability (F) of rHV2-K47 via oral route reached 10.11% in comparison with intravenous administration as gold standard. All the results suggested that rHV2-K47 could be delivered successfully via the oral route.     

DNA damage during G2 phase does not affect cell cycle progression of the green alga Scenedesmus quadricauda

DNA damage is a threat to genomic integrity in all living organisms. Plants and green algae are particularly susceptible to DNA damage especially that caused by UV light, due to their light dependency for photosynthesis. For survival of a plant, and other eukaryotic cells, it is essential for an organism to continuously check the integrity of its genetic material and, when damaged, to repair it immediately. Cells therefore utilize a DNA damage response pathway that is responsible for sensing, reacting to and repairing damaged DNA. We have studied the effect of 5-fluorodeoxyuridine, zeocin, caffeine and combinations of these on the cell cycle of the green alga Scenedesmus quadricauda. The cells delayed S phase and underwent a permanent G2 phase block if DNA metabolism was affected prior to S phase; the G2 phase block imposed by zeocin was partially abolished by caffeine. No cell cycle block was observed if the treatment with zeocin occurred in G2 phase and the cells divided normally. CDKA and CDKB kinases regulate mitosis in S. quadricauda; their kinase activities were inhibited by Wee1. CDKA, CDKB protein levels were stabilized in the presence of zeocin. In contrast, the protein level of Wee1 was unaffected by DNA perturbing treatments. Wee1 therefore does not appear to be involved in the DNA damage response in S. quadricauda. Our results imply a specific reaction to DNA damage in S. quadricauda, with no cell cycle arrest, after experiencing DNA damage during G2 phase.     

Experimental RNomics and genomic comparative analysis reveal a large group of species-specific small non-message RNAs in the silkworm Bombyx mori

Accumulating evidences show that small non-protein coding RNAs (ncRNAs) play important roles in development, stress response and other cellular processes. The silkworm is an important model for studies on insect genetics and control of lepidopterous pests. Here, we have performed the first systematic identification and analysis of intermediate size ncRNAs (50-500 nt) in the silkworm. We identified 189 novel ncRNAs, including 141 snoRNAs, six snRNAs, three tRNAs, one SRP and 38 unclassified ncRNAs. Forty ncRNAs showed significantly altered expression during silkworm development or across specific stage transitions. Genomic comparisons revealed that 123 of these ncRNAs are potentially silkworm-specific. Analysis of the genomic organization of the ncRNA loci showed that 32.62% of the novel snoRNA loci are intergenic, and that all the intronic snoRNAs follow the pattern of one-snoRNA-per-intron. Target site analysis predicted a total of 95 2'-O-methylation and pseudouridylation modification sites of rRNAs, snRNAs and tRNAs. Together, these findings provide new clues for future functional study of ncRNA during insect development and evolution.     

甾体激素对C6细胞摄取甘氨酸的快速作用

目的 :探讨甾体激素对C6细胞摄取甘氨酸快速作用的非基因组织机制。方法 :应用液体闪烁技术 ,通过检测C6细胞在加入了甾体激素和 /或其它试剂后摄入标记甘氨酸量的改变 ,确定甾体激素的作用。结果 :C6细胞高亲合力的甘氨酸依赖于钠离子和氯离子。皮质酮 ,孕酮 ,地塞米松可快速抑制这种摄取 ,雌二醇 ,脱氧皮质酮无显著的抑制作用 ,表明甾体激素作用有特异性。皮质酮的作用在 10 4 -8～ 10 -6 mmol/L范围内效应与浓度成正相关。皮质酮偶联牛血清蛋白后作用依然存在。RU38486 能部分阻断皮质酮的效应。细胞外液钙离子缺乏时皮质酮的作用基本消失。结论 :虽然皮质酮 ,孕酮 ,地塞米松神经胶质细胞和神经元摄取甘氨酸的快速作用不一样 ,但均是非基因组机制。     

Isoform-selective inhibition of chrysin towards human cytochrome P450 1A2. Kinetics analysis,molecular docking,and molecular dynamics simulations

Our kinetics studies demonstrated that the nature product chrysin exhibited a high inhibitory affinity of 54 nM towards human cytochrome P450 1A2 and was comparable to α-naphthoflavone (49 nM), whereas it represented a moderate affinity of 5225 nM against human cytochrome P450 2C9. However, it remains unclear how this inhibitor selectively binds 1A2. To better understand the isoform selectivity of chrysin, molecular docking and molecular dynamics simulations were performed. Chrysin formed a strong H-bond with Asp313 of 1A2. The stacking interactions with Phe226 also contributed to its tight binding to 1A2. The larger and much more open active site architectures of 2C9 may explain the weaker inhibitory affinity of chrysin towards 2C9. The predicted binding free energies suggest that chrysin preferred 1A2 (ΔG_{bind, pred} = ?23.11 kcal/mol) to 2C9 (?20.41 kcal/mol). Additionally, the present work revealed that 7-hydroxy-flavone bound to 1A2 in a similar pattern as chrysin and represented a slightly less negative predicted binding free energy, which was further validated by our kinetics analysis (IC₅₀ = 240 nM). Results of the study can provide insight for designing novel isoform-selective 1A2 inhibitors.     

Ectopic Osteoid and Bone Formation by Three Calcium-Phosphate Ceramics in Rats,Rabbits and Dogs

Calcium phosphate ceramics with specific physicochemical properties have been shown to induce de novo bone formation upon ectopic implantation in a number of animal models. In this study we explored the influence of physicochemical properties as well as the animal species on material-induced ectopic bone formation. Three bioceramics were used for the study: phase-pure hydroxyapatite (HA) sintered at 1200°C and two biphasic calcium phosphate (BCP) ceramics, consisting of 60 wt.% HA and 40 wt.% TCP (β-Tricalcium phosphate), sintered at either 1100°C or 1200°C. 108 samples of each ceramic were intramuscularly implanted in dogs, rabbits, and rats for 6, 12, and 24 weeks respectively. Histological and histomorphometrical analyses illustrated that ectopic bone and/or osteoid tissue formation was most pronounced in BCP sintered at 1100°C and most limited in HA, independent of the animal model. Concerning the effect of animal species, ectopic bone formation reproducibly occurred in dogs, while in rabbits and rats, new tissue formation was mainly limited to osteoid. The results of this study confirmed that the incidence and the extent of material-induced bone formation are related to both the physicochemical properties of calcium phosphate ceramics and the animal model.