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991.
Lina Li Lei Chang Stéphane Pellet-Rostaing François Liger Marc Lemaire René Buchet Yuqing Wu 《Bioorganic & medicinal chemistry》2009,17(20):7290-7300
Presence of basic calcium phosphate in knee joints of osteoarthritis patients could be prevented by inhibiting tissue non-specific alkaline phosphatase (TNAP) activity. Levamisole or the L stereoisomer of tetramisole (a known TNAP inhibitor) has been used as a treatment for curing rheumatoid arthritis but its therapeutical use is limited due to side effects. We report the synthesis and the TNAP inhibition property of benzo[b]thiophene derivatives, among which benzothiopheno-tetramisole and benzothiopheno-2,3-dehydrotetramisole, which could be involved in a drug therapy for osteoarthritis. Two water soluble racemic benzothiopheno-tetramisole and -2,3-dehydrotetramisole with apparent inhibition constants Ki = 85 ± 6 μM and 135 ± 3 μM (n = 3) comparable to that of enantiomeric levamisole 93 ± 4 μM were found. Several novel derivatives showed more pronounced inhibition properties towards intestinal alkaline phosphatase than TNAP. 相似文献
992.
Mingliang Chen Xiaoye Shen Daofeng Li Lei Ma Jiangli Dong Tao Wang 《Plant Physiology and Biochemistry》2009,47(11-12):1089-1094
Zn is an essential micronutrient in plants, and the mechanisms of Zn homeostasis are under intensive study. In this report, we have identified MtMTP1, a Zn transporter of the CDF family in the legume model plant Medicago truncatula. The ORF of the MtMTP1 cDNA encodes a protein consisting of 407 amino acid residues with a predicted molecular mass of 45 kDa. Like other metal tolerance proteins (MTPs) in plants, heterologous expression of MtMTP1 can complement the Zn-susceptible zrc1 cot1 yeast double mutant. The expression pattern was studied by quantitative fluorescent PCR. The expression of MtMTP1 was detected in all vegetative organs with the highest level of expression observed in leaves. With Zn supplementation its expression in roots was reduced while its expression in stems was increased in the first 2 days. No obvious changes were detected in leaves. Inoculation with Rhizobium meliloti down-regulated its expression in roots. 相似文献
993.
Hongli Li Yingbiao Zhi Shuqing An Lei Zhao Changfang Zhou Zifa Deng Shuping Gu 《Ecological Engineering》2009,35(4):544-552
The exotic species Spartina anglica C.E. Hubbard has been experiencing dieback in coastal China during the past decade, while it is invading other places in the world. Thus, an explanation for the dieback of the populations in coastal China would be helpful for controlling invasions of S. anglica in other places of the world. Both field and greenhouse experiments were conducted to determine the possible role of density in the dieback of the populations in China. The density effects were tested by maintaining six density levels in field experiments and three density levels in greenhouse experiments over 7 months. The results showed that growth, asexual reproduction and biomass accumulation in medium density were significantly higher than those in other density treatments for field experiments. The growth and asexual reproduction in high-density patches were lowest among the treatments in the field. Data showed the same pattern for the greenhouse experiments. The results implied that density regulation had a great effect on most of the studied parameters. Because the species is surviving at high density along the Chinese coast, and has a much lower growth rate due to strong intraspecific competition, and also because high-density populations may decline into low density populations due to resource exhaustion, high plant density might be one of the important factors in the dieback of S. anglica. 相似文献
994.
Essential role for the Pak4 protein kinase in extraembryonic tissue development and vessel formation
Yanmei Tian Liang Lei Marta Cammarano Tanya Nekrasova Audrey Minden 《Mechanisms of development》2009,126(8-9):710-720
Pak4 is a member of the group B family of Pak serine/threonine kinases, originally identified as an effector protein for the Rho GTPase Cdc42. Pak4 knockout mice are embryonic lethal and do not survive past embryonic day 11.5. Previous work on Pak4 knockout mice has focused on studying the phenotype of the embryo. Abnormalities in the extraembryonic tissue, however, are common causes of early embryonic death in knockout mice. Extraembryonic tissue associated with the Pak4-null embryos was therefore examined. Abnormalities in both yolk sacs and placentas resulted when Pak4 was deleted. These included a lack of vasculature throughout the extraembryonic tissue, as well as an abnormally formed labyrinthine layer of the placenta. Interestingly, epiblast-specific deletion of Pak4 using a conditional knockout system, did not rescue the embryonic lethality. In fact, it did not even rescue the extraembryonic tissue defects. Our results suggest that the extraembryonic tissue abnormalities are secondary to defects that occur in response to epiblast abnormalities. More detailed analysis suggests that abnormalities in vasculature throughout the extraembryonic tissue and the epiblast may contribute to the death of the Pak4-null embryos. 相似文献
995.
PurposeThe purpose of this study was to investigate the anti-angiogenic properties of julibroside J8, a triterpenoid saponin isolated from Albizia julibrissin.MethodsIn the presence of juliborside J8, the growth of human microvascular endothelial cells (HMEC-1), four human tumor cell lines, and a normal cell line (MRC-5) was evaluated by MTT assay. The in vivo anti-angiogenic effect of julibroside J8 was evaluated on a chorioallantoic membrane (CAM) and in transplanted colon carcinoma cells in a nude mice neovascularisation model.ResultsTreatment with 0.5–4 μg/ml julibroside J8 resulted in dose-dependent inhibition of growth, migration, and tube formation in HMEC-1 cells; julibroside J8 also inhibited the formation of microvessels on CAM at a concentration of 10–50 μg/egg and reduced vessel density within tumor at a concentration of 0.5–3 mg/kg.ConclusionsJulibroside J8 may be a potent anti-angiogenetic and cytotoxic drug; further investigation is warranted. 相似文献
996.
Chuck T. Chen Zhen Liu Melissa Ouellet Frédéric Calon Richard P. Bazinet 《Prostaglandins, leukotrienes, and essential fatty acids》2009,80(2-3):157-163
Analyses of brain phospholipid fatty acid profiles reveal a selective deficiency and enrichment in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively. In order to account for this difference in brain fatty acid levels, we hypothesized that EPA is more rapidly β-oxidized upon its entry into the brain. Wild-type C57BL/6 mice were perfused with either 14C-EPA or 14C-DHA via in situ cerebral perfusion for 40 s, followed by a bicarbonate buffer to wash out the residual radiolabeled polyunsaturated fatty acid (PUFA) in the capillaries. 14C-PUFA-perfused brains were extracted for chemical analyses of neutral lipid and phospholipid fatty acids. Based on the radioactivity in aqueous, total lipid, neutral lipid and phospholipid fractions, volume of distribution (VD, μl/g) was calculated. The VD between 14C-EPA- and 14C-DHA-perfused samples was not statistically different for total lipid, neutral lipids or total phospholipids. However, the VD of 14C-EPA in the aqueous fraction was 2.5 times higher than that of 14C-DHA (p=0.025), suggesting a more extensive β-oxidation than DHA. Furthermore, radiolabeled palmitoleic acid, a fatty acid that can be synthesized de novo, was detected in brain phospholipids from 14C-EPA but not from 14C-DHA-perfused mice suggesting that β-oxidation products of EPA were recycled into endogenous fatty acid biosynthetic pathways. These findings suggest that low levels of EPA in brain phospholipids compared to DHA may be the result of its rapid β-oxidation upon uptake by the brain. 相似文献
997.
998.
Xiao Hu Ge Qin Wang Zhong Ming Qian Li Zhu Fang Du Wing Ho Yung Lei Yang Ya Ke 《The Journal of nutritional biochemistry》2009,20(11):860-865
Iron plays a key pathophysiological role in a number of cardiac diseases. Studies on the mechanisms of heart iron homeostasis are therefore crucial for understanding the causes of excessive heart iron. In addition to iron uptake, cellular iron balance in the heart also depends on iron export. We provided evidence for the existence of iron exporter ferroportin 1 (Fpn1) in the heart in a recent study. The presence of hepcidin, a recently discovered iron regulatory hormone, was also confirmed in the heart recently. Based on these findings and the inhibiting role of hepcidin on Fpn1 in other tissues, we speculated that hepcidin might be able to bind with, internalize and degrade Fpn1 and then decrease iron export in heart cells, leading to an abnormal increase in heart iron and iron mediated cell injury. We therefore investigated the effects of hepcidin on the contents of Fpn1 and iron release in H9C2 cardiomyocyte cell line. We demonstrated that hepcidin has the ability to reduce Fpn1 content as well as iron release in this cell. The similar regulation patterns of hepcidin on the Fpn1 and iron release suggested that the decreased iron release resulted from the decreased content of Fpn1 induced by hepcidin. We also found that hepcidin has no significant effects on ceruloplasmin (CP) and hephaestin (Heph) — two proteins required for iron release from mammalian cells. The data imply that Fpn1, rather than Heph and CP, is the limited factor in the regulation of iron release from heart cells under physiological conditions. 相似文献
999.
Zhong Li Ruo-Wei Chen Heng-Yi Lei Zhong Shan Tao Bai Qiang Yu Hua-Liang Li 《World journal of microbiology & biotechnology》2009,25(5):745-752
We studied a novel bioflocculant, PX, that is produced from Bacillus Bacillus circulans X3, and has excellent flocculating activity with regard to its characterization and flocculating properties. The bioflocculant
was purified from supernatant by ethanol precipitation, dialysis and gel permeation chromatography (GPC). The major component
of PX was an acid polysaccharide including uronic (19.8%), pyruvic (6.5%) and acetic acids (0.7%). It consisted of galactose,
mannose, xylitol, rhamnose and galacturonic acid in an approximate molar ration of 5:4.1:3:2:1.2. The molecular weight of
PX was about 4.85 × 104 Da as determined by GPC. The infrared spectrum of the bioflocculant indicated the presence of carboxyl, hydroxyl, amino and
methoxyl groups. Studies of the flocculating properties revealed that it was stable at 60–100°C and pH 4–10. Moreover, it
could flocculate a kaolin suspension over a wide range of pH and temperature in the presence of CaCl2. 相似文献
1000.
Tao Zhang Lei Li Xiao-fen Wang Zhao-hai Zeng Yue-gao Hu Zong-jun Cui 《World journal of microbiology & biotechnology》2009,25(6):965-971
Silages are important feedstuffs. Homofermentative lactic acid bacterial inoculants are often used to control silage fermentation.
However, some research pointed out those homofermentative lactic acid bacteria (LAB) impaired the aerobic stability of wheat,
sorghum, and corn silages. Adding heterofermentative LAB can produce more acetic acid, thereby stabilizing silages during
aerobic exposure. Alfalfa is difficult to ensile. The present work was to study the effects of L. buchneri (heterofermentative LAB), alone or in combination with L. plantarum (homofermentative LAB) on the fermentation, aerobic stability, bacteria diversity and ruminal degradability of alfalfa silage.
After 90 days ensiling, the pH, NH3-N/TN, butyric acid content and molds counts of control were the highest. The inoculated silages had more lactic acid, acetic
acid content and more lactic acid bacteria than the control. Inoculating LAB inhibited harmful microorganisms, such as Enterobacterium and Klebsiella pneumoniae. The L. buchneri + L. plantarum-inoculated silage had more acetic acid and less yeasts than other three treatments (P < 0.05), and lower NH3-N/TN than control (P < 0.05). The CO2 production of L. buchneri + L. plantarum-inoculated silage was less than that of L. plantarum-inoculated silage (P < 0.05). Inoculating LAB in alfalfa silages can decrease pH, increase the production of lactic and acetic acids, reduce the
number of yeasts and molds, and inhibit Enterobacterium and K. pneumoniae. Inoculating with L. buchneri or L. buchneri + L. plantarum can improve aerobic stability of alfalfa silages. A combination of L. buchneri and L. plantarum is preferable because it enhanced alfalfa silage quality and aerobic stability. 相似文献