Analysis of metabolic pathway using hybrid properties

Given a compounds-forming system, i.e., a system consisting of some compounds and their relationship, can it form a biologically meaningful pathway? It is a fundamental problem in systems biology. Nowadays, a lot of information on different organisms, at both genetic and metabolic levels, has been collected and stored in some specific databases. Based on these data, it is feasible to address such an essential problem. Metabolic pathway is one kind of compounds-forming systems and we analyzed them in yeast by extracting different (biological and graphic) features from each of the 13,736 compounds-forming systems, of which 136 are positive pathways, i.e., known metabolic pathway from KEGG; while 13,600 were negative. Each of these compounds-forming systems was represented by 144 features, of which 88 are graph features and 56 biological features. "Minimum Redundancy Maximum Relevance" and "Incremental Feature Selection" were utilized to analyze these features and 16 optimal features were selected as being able to predict a query compounds- forming system most successfully. It was found through Jackknife cross-validation that the overall success rate of identifying the positive pathways was 74.26%. It is anticipated that this novel approach and encouraging result may give meaningful illumination to investigate this important topic.     

不同降水条件下科尔沁沙地南缘疏林草地樟子松针叶δ13C和叶性状特征

通过比较不同自然降水年份(极端干旱和极端湿润)19年生疏林草地樟子松的针叶δ¹³C、比叶面积和干物质含量,结合土壤含水量和地下水埋深,探讨了极端降水对樟子松水分利用的影响.结果表明: 干旱年份(2009)樟子松林土壤含水量显著低于湿润年份(2010),但樟子松当年生针叶的δ¹³C在两年间没有显著差异,且两年相同月份间亦无显著差异;干旱年份当年生针叶的比叶面积显著低于湿润年份,而不同年份间干物质含量的差异不显著.在两种极端降水条件下,樟子松的水分利用效率没有明显变化,主要通过改变当年生针叶的比叶面积来适应降水量的变化.对于地下水埋深高于3.0 m的疏林草地樟子松人工林生态系统,极端干旱不会严重影响樟子松的存活和生长.     

Development of pig embryos by nuclear transfer of cultured fibroblast cells

Pig fibroblast cells were transferred to enucleated oocytes by micromanipulation and electrofusion. The donor cells used for nuclear transfer were synchronized in presumptive G0 by serum starvation. In the first experiment, nuclear transfer was performed with fibroblasts that had either a smooth or a rough surface. A significant difference (p < 0.05) in the percentage of chromosome condensation (39.5%, 15/38 and 16.6%, 5/30) and nuclear formation (36.8%, 14/38 and 16.3%, 8/49) was found between the reconstructed embryos derived from the cells with smooth surface and with rough surfaces, respectively. The percentage of chromosome condensation (42.5%, 17/40 and 19.6%, 11/56) and nuclear formation (38.3%, 23/60 and 18.8%, 9/48) were higher (p < 0.05) in reconstructed embryos derived from small (15 microm) donor cells compared to large donor cells (20 microm), respectively. The percentage nuclei at 3 different time points (3, 6, and 9 hours in culture medium) was higher (p = 0.003) in the reconstructed embryos activated by thimerosal and dithiothreitol (20%, 36%, and 41.3%) compared to those without activation treatment (0%, 11.8%, and 22.2%). In addition, there was an increased percentage with nuclei as the time in culture increased from 3 to 9 hours (p = 0.029). The percentages of chromosome condensation (34.6%; 9/26) and nuclear formation (33.3%; 9/27) in nuclear transfer embryos were similar. The rate of blastocysts/morulae development (14.0%; 6/43) was low. However, 2 cavitated embryos (presumptive blastocysts) with 14 and 11 nuclei and 1 morula with 8 nuclei were obtained. This together with the above evidence indicate that the nuclei from pig fibroblast cells can be partially reprogrammed, which suggests that transfer of nuclei from fibroblast cells to in vitro matured oocytes resulting in production of identical or genetically altered pigs may be possible.     

中国新栎盾蚧属一新种及二新纪录种(同翅目:蚧总科:盾蚧科)

记述新栎盾蚧属Neoquernaspis Howell et Takagi,1981一新种,即细管新栎盾蚧N.leptosipha sp.nov和2种中国分布新纪录种,即石柯新栎盾蚧N.beshearae Liu et Tippins,1988和尼泊尔新栎盾蚧N.nepalensis (Takagi,1977),并编制了该属中国已知种类检索表,新种模式标本和新纪录标本保存于西北农业大学昆虫博物馆。     

The specific binding activities of human urinary radioiodinated colony-stimulating factor-1 to various human tissue cells

1. Colony-stimulating factor (CSF-1) was isolated from a large volume of fresh normal human urine by 5 steps of purification and enrichment. 2. The purification factor is 100,000 fold and the purified compound exhibits a 2.16 x 10(7) U/mg of protein sp. act. 3. The isolated CSF-1 is a sialoglycoprotein with 41.5% of carbohydrate. The almost complete removal of this carbohydrate moiety (up to 91%) was achieved by incubation with trifluoromethane sulfonic acid. 4. The deglycosylated CSF-1 (DG-CSF-1) possesses an apparent Mr 38,000 compared to native CSF-1 with an initial Mr 57,000 (Goa et al., 1988). 5. The features of the interaction of radio-iodinated [125I]CSF-1 with single cell suspensions from various human tissues (bone marrow, spleen, blood, peritoneal cavity, alveolar lavage, lymph node and thymus), were studied. 6. The binding activity of peritoneal macrophages was the highest among the cells examined and erythrocytes, thymus and blood granulocytes showed no CSF-1 binding. 7. On incubation with [125I]CSF-1 at 0 degrees C, cellular binding of [125I]CSF-1 reached a stable maximum within 16 hr. This is in contrast to the association behaviour at higher temperature. 8. At 37 degrees C, cellular associated [125I]CSF-1 levels reached, within 90 min, an unstable maximum which was up to 10 times less than that occurring under the same conditions at 0 degree C. From the Scatchard plot analysis, we obtained the affinity constant and the number of receptor(s). 9. The binding site is sensitive to trypsin. 10. The receptor alone, (labelled by cross-linking to [125I]CSF-1 with di-succinylimidyl-suberate), is a polypeptide with an approx. Mr 110,000. 11. Our results showed that the receptor of CSF-1 is a tyrosin-kinase.     

Induction of IL-6 release from human T cells by PAR-1 and PAR-2 agonists

Proteinase-activated receptors (PAR) have been recognized as playing an important role in inflammation and immune response. However, little is known of the expression and function of PAR on human T cells. In this study, the expression of PAR on highly purified human T cells was determined and the secretion of IL-6 from cultured T cells in response to serine proteinases and agonist peptides of PAR was examined. The results showed that T cells express PAR-1, PAR-2 and PAR-3 proteins and genes. Thrombin, trypsin and tryptase, but not elastase, were able to stimulate concentration-dependent secretion of IL-6 from T cells following a 16 h incubation period. The specific inhibitors of thrombin, trypsin and tryptase inhibited the actions of these proteinases on T cells, indicating that the enzymatic activity is essential for their actions. Agonist peptides of PAR SFLLR-NH2, TFLLRN-NH2 and SLIGKV-NH2, but not TFRGAP-NH2, GYPGQV-NH2 and AYPGKF-NH2, are also capable of inducing IL-6 release from T cells. In conclusion, induction of IL-6 secretion from T cells by thrombin, trypsin and tryptase is probably through the activation of PAR, suggesting that serine proteinases are involved in the regulation of immune response of the body.     

Anticancer activities of a chemically sulfated polysaccharide obtained from Grifola frondosa and its combination with 5-Fluorouracil against human gastric carcinoma cells

Chemically sulfated polysaccharide (S-GAP-P) was derived from water-insoluble polysaccharide of Grifola frondosa mycelia. In this research, we investigated the anticancer effects of S-GAP-P and its combination with 5-fluorouracil (5-FU) on human gastric carcinoma SGC-7901 cells. Results showed that S-GAP-P distinctly inhibited SGC-7901 cells growth in a dose-dependent manner and induced cell apoptosis evidenced by characteristic DNA ladder and sub-G₀/G₁ peak. Furthermore, the combination of S-GAP-P (10–50 μg/ml) with 1 μg/ml 5-FU resulted in a significant inhibition on SGC-7901 cells growth, meaning the beneficial interaction between the two drugs. All these results suggested that S-GAP-P has evident anticancer activity through apoptotic induction and could significantly accelerate the anticancer activity of 5-FU.     

基于大鼠在体肠灌流模型研究白及有效部位在肠道的可吸收及代谢成分

为了考查白及有效部位在肠道的可吸收成分及其代谢特征。基于在体肠灌流模型,采用超高效液相色谱-四极杆-飞行时间质谱仪(UPLC-Q-TOF/MS)对收集到的健康SD大鼠循环肠灌流液、血清、胆汁进行分析检测,并结合对照品、质谱碎片信息和Masslynx V4.1工作站中的Single Mass Analysis功能,初步推测吸收和代谢产物的结构式。在大鼠血清和胆汁中,初步鉴定出1,4-二[4-(葡萄糖氧)苄基]-2-异丁基苹果酸、4-(葡萄糖氧)苄基]-2-异丁基苹果酸酯、α-异丁基苹果酸酯原型产物。在大鼠循环肠灌流液、血清和胆汁中,共鉴定出4-(葡萄糖氧)苄基]-2-异丁基苹果酸酯的脱糖后硫酸化代谢产物和二氢菲5的葡萄糖醛酸化代谢产物,其代谢产物主要生水解和葡萄糖醛酸化反应。该方法初步探究了白及有效部位在大鼠循环肠灌流液中可吸收成分和代谢特征,为阐释白及药材的药效物质基础提供实验依据。     

Flowering-Related RING Protein 1 (FRRP1) Regulates Flowering Time and Yield Potential by Affecting Histone H2B Monoubiquitination in Rice (Oryza Sativa)

Flowering time is a critical trait for crops cultivated under various temperature/photoperiod conditions around the world. To understand better the flowering time of rice, we used the vector pTCK303 to produce several lines of RNAi knockdown transgenic rice and investigated their flowering times and other agronomic traits. Among them, the heading date of FRRP1-RNAi knockdown transgenic rice was 23–26 days earlier than that of wild-type plants. FRRP1 is a novel rice gene that encodes a C3HC4-type Really Interesting Novel Gene (RING) finger domain protein. In addition to the early flowering time, FRRP1-RNAi knockdown transgenic rice caused changes on an array of agronomic traits, including plant height, panicle length and grain length. We analyzed the expression of some key genes associated with the flowering time and other agronomic traits in the FRRP1-RNAi knockdown lines and compared with that in wild-type lines. The expression of Hd3a increased significantly, which was the key factor in the early flowering time. Further experiments showed that the level of histone H2B monoubiquitination (H2Bub1) was noticeably reduced in the FRRP1-RNAi knockdown transgenic rice lines compared with wild-type plants and MBP-FRRP1-F1 was capable of self-ubiquitination. The results indicate that Flowering Related RING Protein 1 (FRRP1) is involved in histone H2B monoubiquitination and suggest that FRRP1 functions as an E3 ligase in vivo and in vitro. In conclusion, FRRP1 probably regulates flowering time and yield potential in rice by affecting histone H2B monoubiquitination, which leads to changes in gene expression in multiple processes.