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991.
R B Lingham B H Arison L F Colwell A Hsu G Dezeny W J Thompson G M Garrity M M Gagliardi F W Hartner P L Darke 《Biochemical and biophysical research communications》1991,181(3):1456-1461
L-689,502 is a potent inhibitor of HIV-1 protease activity in vitro. Microbial biotransformations of L-689,502 by cultures belonging to the genus Streptomyces sp. were performed. Extracts of culture broths were examined for the production of metabolites of L-689,502 that could inhibit HIV-1 protease activity. One culture, MA 6804 (Streptomyces lavendulae, ATCC 55095), produced L-694,746 that, while being structurally related to L-689,502, is a novel metabolite and a potent inhibitor of HIV-1 protease. 相似文献
992.
Hsu Chih-Yun Yu Nai-Wen Ku Hung-Hai Chang Li-Tze Liu Hwan-Wun 《Development, growth & differentiation》1991,33(3):201-208
Female tadpoles of Rana catesbeiana were laparotomized at metamorphic stages XI-XIII and an empty capsule or one containing cyanoketone (CK), which is an inhibitor of Δ5 -3β-hydroxysteroid dehydrogenase (Δ5 -3β-HSD), was implanted intraperitoneally. Ovarian activity of Δ5 -3β-HSD was examined histochemically 2 months later, estradiol-17β (E2 ) secretion by the ovaries was measured by RIA 4 months later and histological changes of the ovaries were examined 6 months later. The Δ5 -3β-HSD activity of the CK-treated ovaries was much lower than that of controls. E2 secretion per froglet by CK-treated ovaries was about one third that of controls (p<0.001). Histological examination showed various degrees of masculinization of the ovaries, about 28% of which were totally transformed into testis-like structures.
As a result of suppressed Δ5 -3β-HSD activity, dehydroepiandrosterone would have accumulated, resulting in deficient E2 secretion and, therefore, ovarian masculinization. In tadpoles, this effect does not depend on the pituitary, whereas interrenal hyperplasia and hyperactivity do, indicating that interrenal function is not essential for ovarian masculinization. From these findings and our previous results, we suggest that disturbance of steroidogenesis by CK in the ovaries results in their masculinization. 相似文献
As a result of suppressed Δ
993.
CME‐1, a novel polysaccharide,suppresses iNOS expression in lipopolysaccharide‐stimulated macrophages through ceramide‐initiated protein phosphatase 2A activation
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![点击此处可从《Journal of cellular and molecular medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Joen‐Rong Sheu Zhih‐Cherng Chen Ming‐Jen Hsu Shwu‐Huey Wang Kuo‐Wei Jung Wei‐Fan Wu Szu‐Han Pan Ruei‐Dun Teng Chih‐Hao Yang Cheng‐Ying Hsieh 《Journal of cellular and molecular medicine》2018,22(2):999-1013
CME‐1, a novel water‐soluble polysaccharide purified from Ophiocordyceps sinensis mycelia, has anti‐oxidative, antithrombotic and antitumour properties. In this study, other major attributes of CME‐1, namely anti‐inflammatory and immunomodulatory properties, were investigated. Treating lipopolysaccharide (LPS)‐stimulated RAW 264.7 cells with CME‐1 concentration‐dependently suppressed nitric oxide formation and inducible nitric oxide synthase (iNOS) expression. In the CME‐1‐treated RAW 264.7 cells, LPS‐induced IκBα degradation and the phosphorylation of p65, Akt and mitogen‐activated protein kinases (MAPKs), including extracellular signal‐regulated kinase, c‐Jun N‐terminal kinase and p38, were reduced. Treatment with a protein phosphatase 2A (PP2A)‐specific inhibitor, significantly reversed the CME‐1‐suppressed iNOS expression; IκBα degradation; and p65, Akt and MAPK phosphorylation. PP2A activity up‐regulation and PP2A demethylation reduction were also observed in the cells. Moreover, CME‐1‐induced PP2A activation and its subsequent suppression of LPS‐activated RAW 264.7 cells were diminished by the inhibition of ceramide signals. LPS‐induced reactive oxygen species (ROS) and hydroxyl radical formation were eliminated by treating RAW 264.7 cells with CME‐1. Furthermore, the role of ceramide signalling pathway and anti‐oxidative property were also demonstrated in CME‐1‐mediated inhibition of LPS‐activated primary peritoneal macrophages. In conclusion, CME‐1 suppressed iNOS expression by up‐regulating ceramide‐induced PP2A activation and reducing ROS production in LPS‐stimulated macrophages. CME‐1 is a potential therapeutic agent for treating inflammatory diseases. 相似文献
994.
Mitogen‐activated protein kinase phosphatase 1 reduces the replication efficiency of Bamboo mosaic virus in Nicotiana benthamiana
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Cheng‐Cheng Lee Yi‐Jhen Wu Chia‐Hsin Hsueh Yu‐Ting Huang Yau‐Heiu Hsu Menghsiao Meng 《Molecular Plant Pathology》2018,19(10):2319-2332
In plants, the mitogen‐activated protein kinase (MAPK) cascades are the central signaling pathways of the complicated defense network triggered by the perception of pathogen‐associated molecular patterns to repel pathogens. The Arabidopsis thaliana MAPK phosphatase 1 (AtMKP1) negatively regulates the activation of MAPKs. Recently, the AtMKP1 homolog of Nicotiana benthamiana (NbMKP1) was found in association with the Bamboo mosaic virus (BaMV) replication complex. This study aimed to investigate the role of NbMKP1 in BaMV multiplication in N. benthamiana. Silencing of NbMKP1 increased accumulations of the BaMV‐encoded proteins and the viral genomic RNA, although the same condition reduced the infectivity of Pseudomonas syringae pv. tomato DC3000 in N. benthamiana. On the other hand, overexpression of NbMKP1 decreased the BaMV coat protein accumulation in a phosphatase activity‐dependent manner in protoplasts. NbMKP1 also negatively affected the in vitro RNA polymerase activity of the BaMV replication complex. Collectively, the activity of NbMKP1 seems to reduce BaMV multiplication, inconsistent with the negatively regulatory role of MKP1 in MAPK cascades in terms of warding off fungal and bacterial invasion. In addition, silencing of NbMKP1 increased the accumulation of Foxtail mosaic virus but decreased Potato virus X. The discrepant effects exerted by NbMKP1 on different pathogens foresee the difficulty to develop plants with broad‐spectrum resistance through genetically manipulating a single player in MAPK cascades. 相似文献
995.
The implementation of the consensus on the management of Helicobacter pylori and barriers to consensus
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![点击此处可从《Helicobacter》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hsiu‐Chi Cheng Jyh‐Ming Liou Jiing‐Chyuan Luo Cheng‐Tang Chiu Ming‐Shiang Wu Yi‐Chia Lee Chun‐Ying Wu Deng‐Chyang Wu Ping‐I Hsu Chun‐Chao Chang Wei‐Lun Chang Jaw‐Town Lin Bor‐Shyang Sheu 《Helicobacter》2018,23(5)
Background
A consensus on the management of Helicobacter pylori has been developed. We aimed to assess whether dissemination through continuing medical education (CME) could enhance the adoption of this consensus among clinicians and to explore potential barriers to acceptance.Materials and methods
Four CME courses were held to disseminate the consensus. Adoption surveys were performed to evaluate participants’ behavior in the past and their commitment to adopt the consensus in future clinical practice after CME. The gaps and barriers to adoption were also surveyed.Results
A total of 240 physicians had attended the CME courses and received surveys with the 22 statements/substatements of the consensus. Before CME, adoption was good in six, fair in ten, and poor in six. After CME, 21 statements had either an initial >90% adoption or improvement to good or fair (P < 0.001), but one still had poor even though it showed improvement (P = 0.02). Although commitment was good or fair after CME, there was a >20% gap between “commitment” and “no barrier” to adoption for 11 statements, ten of which had a main barrier of financial incentives. Among the statements with fair or poor commitment after CME, less commitment to adoption and more barriers related to financial incentives were pronounced in clinicians serving in regional/district hospitals or clinics compared to those serving in medical centers.Conclusions
Continuing medical education may improve the adoption of the H. pylori consensus. The financial incentives were shown to be a main barrier to adoption of the consensus and should be improved. 相似文献996.
Unraveling Geometrical Site Confinement in Highly Efficient Iron‐Doped Electrocatalysts toward Oxygen Evolution Reaction
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Sung‐Fu Hung Ying‐Ya Hsu Chia‐Jui Chang Chia‐Shuo Hsu Nian‐Tzu Suen Ting‐Shan Chan Hao Ming Chen 《Liver Transplantation》2018,8(7)
Introduction of iron in various catalytic systems has served a crucial function to significantly enhance the catalytic activity toward oxygen evolution reaction (OER), but the relationship between material properties and catalysis is still elusive. In this study, by regulating the distinctive geometric sites in spinel, Fe occupies the octahedral sites (Fe3+(Oh)) and confines Co to the tetrahedral site (Co2+(Td)), resulting in a strikingly high activity (ηj = 10 mA cm?2 = 229 mV and ηj = 100 mA cm?2 = 281 mV). Further enrichment of Fe ions would occupy the tetrahedral sites to decline the amount of Co2+(Td) and deteriorate the OER activity. It is also found that similar tafel slope and peak frequency in Bode plot of electrochemical impedance spectroscopy indicate that Co2+(Td) ions are primarily in charge of water oxidation catalytic center. By means of electrochemical techniques and in situ X‐ray absorption spectroscopy, it is proposed that Fe3+(Oh) ions mainly confine cobalt ions to the tetrahedral site to restrain the multipath transfer of cobalt ions during the dynamic structural transformation between spinel and oxyhydroxide, continuously activating the catalytic behavior of Co2+(Td) ions. This material‐related insight provides an indication for the design of highly efficient OER electrocatalysts. 相似文献
997.
998.
Pei-Chun Lisa Hsu Maureen O’Callaghan Leo Condron Mark R. H. Hurst 《Plant and Soil》2018,425(1-2):43-55
Aims
The mechanisms by which rhizosphere bacteria increase the availability of mineral P precipitates for plant use are understudied. However, Paraburkholderia bryophila Ha185 is known to solubilize inorganic phosphate in vitro via a novel process. Therefore, this study aimed to demonstrate P solubilization by Ha185 in association with roots of perennial ryegrass (Lolium perenne L.).Methods
We developed a gnotobiotic plant assay to assess P solubilization by Ha185 on ryegrass roots under various nutrient conditions. A green fluorescent protein (GFP)-tagged derivative of Ha185 was used in conjunction with fluorescent microscopy and confocal microscopy to visualize colonization of ryegrass roots.Results
Ha185 solubilized mineral P (hydroxyapatite) in association with ryegrass roots and increased ryegrass growth by 20% under P-limited conditions. The GFP-tagged Ha185 strain colonized the rhizoplane and penetrated the primary root of ryegrass, possibly through “crack entry” at the point of lateral root emergence, but also by entering the epidermal cells via root hairs.Conclusions
Ha185 supported ryegrass growth under P-limited conditions, indicating this strain may improve availability of soil P for uptake by ryegrass. Tools developed in this study have broad application in the study of rhizobacteria-plant interactions.999.
Yu-Ru Su Chongzhi Di Stephanie Bien Licai Huang Xinyuan Dong Goncalo Abecasis Sonja Berndt Stephane Bezieau Hermann Brenner Bette Caan Graham Casey Jenny Chang-Claude Stephen Chanock Sai Chen Charles Connolly Keith Curtis Jane Figueiredo Manish Gala Li Hsu 《American journal of human genetics》2018,102(5):904-919
1000.
Cellular energy metabolism maintains young status in old queen honey bees (Apis mellifera)
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Cheng‐Yen Lu Jiantai Timothy Qiu Chin‐Yuan Hsu 《Archives of insect biochemistry and physiology》2018,98(4)
Trophocytes and oenocytes of queen honey bees are used in studies of cellular longevity, but their cellular energy metabolism with age is poorly understood. In this study, the molecules involved in cellular energy metabolism were evaluated in the trophocytes and oenocytes of young and old queen bees. The findings indicated that there were no significant differences between young and old queen bees in β‐oxidation, glycolysis, and protein synthesis. These results indicate that the cellular energy metabolism of trophocytes and oenocytes in old queen bees is similar to young queen bees and suggests that maintaining cellular energy metabolism in a young status may be associated with the longevity of queen bees. Fat and glycogen accumulation increased with age indicating that old queen bees are older than young queen bees. 相似文献