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Kong F, Yang J, Zhen Z, Liang T, Zhu D, Gao R, Xie G. Gene cloning and molecular characterization of a β-glucosidase from Thermotoga naphthophila RUK-10: an effective tool for synthesis of galacto-oligosaccharide and alkyl galactopyranosides. Chem Res Chin Univ 2015. [DOI: 10.1007/s40242-015-5179-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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102
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Cheng C, Sun WK, Liu R, Wang RM, Chen YH, Wang Y, Li JL, Lu XB, Gao R. Comparison of gene expression of Toll-like receptors and antimicrobial peptides in immune organs and tissues between Yorkshire and Tibetan pigs. Anim Genet 2015; 46:272-9. [PMID: 25917299 DOI: 10.1111/age.12286] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2015] [Indexed: 11/29/2022]
Abstract
Toll-like receptors (TLRs), an important family of pattern-recognition receptors, and antimicrobial peptides (AMPs) contribute to the first line of innate protection of mammals against microbes. To compare characteristics of innate immunity between Tibetan and Yorkshire pigs, we investigated the mRNA abundance of TLR genes (TLR1-TLR9) and two AMP-encoding genes (PBD-1 and PR-39) in thymus, spleen, blood, palatine tonsils, and mesenteric and pulmonary hilar lymph nodes of the two breeds at ages of 6, 12 and 24 weeks using quantitative real-time PCR. Results showed that all mRNAs were detected in all tissues. Transcript levels of the major TLR genes of Tibetan pigs were significantly higher than those of Yorkshires in most tissues of the immune system, with a higher abundance of porcine (PBD-1) (beta-defensin-1) and PR-39 mRNA in lymphoid organs and tissues, especially blood, palatine tonsils, and mesenteric and pulmonary hilar lymph nodes. Our data suggest that Tibetan pigs have stronger innate immunity for triggering local and/or systemic immune responses to eliminate infections with pathogenic microorganisms.
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Dong Y, Huang J, Li G, Li L, Li W, Li X, Liu X, Liu Z, Lu Y, Ma A, Sun H, Wang H, Wen X, Xu D, Yang J, Zhang J, Zhao H, Zhou J, Zhu L, Committee Members:, Bai L, Cao K, Chen M, Chen M, Dai G, Ding W, Dong W, Fang Q, Fang W, Fu X, Gao W, Gao R, Ge J, Ge Z, Gu F, Guo Y, Han H, Hu D, Huang W, Huang L, Huang C, Huang D, Huo Y, Jin W, Ke Y, Lei H, Li X, Li Y, Li D, Li G, Li X, Li Z, Liang Y, Liao Y, Liu G, Ma A, Ma C, Ma D, Ma Y, Shen L, Sun J, Sun C, Sun Y, Tang Q, Wan Z, Wang H, Wang J, Wang S, Wang D, Wang G, Wang J, Wu Y, Wu P, Wu S, Wu X, Wu Z, Yang J, Yang T, Yang X, Yang Y, Yang Z, Ye P, Yu B, Yuan F, Zhang S, Zhang Y, Zhang R, Zhang Y, Zhang Y, Zhao S, Zhou X. Guidelines for the prevention, diagnosis, and treatment of infective endocarditis in adults: The Task Force for the Prevention, Diagnosis, and Treatment of Infective Endocarditis in Adults of Chinese Society of Cardiology of Chinese Medical Association, and of the Editorial Board of Chinese Journal of Cardiology. Eur Heart J Suppl 2015. [DOI: 10.1093/eurheartj/suv031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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104
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Yang J, Di X, Wang M, Gao R. Gene clone and characterization of a novel thermostable β-galactosidase with transglycosylation activity from Thermotoga naphthophila RUK-10. Chem Res Chin Univ 2015. [DOI: 10.1007/s40242-015-5032-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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105
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Li C, Zuo W, Tong X, Hu H, Qiao L, Song J, Xiong G, Gao R, Dai F, Lu C. A composite method for mapping quantitative trait loci without interference of female achiasmatic and gender effects in silkworm,Bombyx mori. Anim Genet 2015; 46:426-32. [DOI: 10.1111/age.12311] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2015] [Indexed: 11/27/2022]
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106
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Mao R, Zhang Y, Ren L, Tian L, Gao R, Ge H, Yin F. SU-E-T-293: Dosimetric Analysis of Microscopic Disease in SBRT for Lung Cancers. Med Phys 2015. [DOI: 10.1118/1.4924655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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107
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Li R, Perez B, Jian H, Gao R, Dong M, Guo Z. Acyl-peptide releasing enzyme from Sulfolobus tokodaii (ST0779) as a novel promiscuous biocatalyst for aldol addition. CATAL COMMUN 2015. [DOI: 10.1016/j.catcom.2015.03.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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108
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Zhang Y, Yin F, Mao R, Gao R, Ren L. WE-AB-303-01: FEATURED PRESENTATION: A Dual-Detector Phase-Matched Digital Tomosynthesis (DTS) Imaging Scheme Using Aggregated KV and MV Projections for Intra-Treatment Lung Tumor Tracking. Med Phys 2015. [DOI: 10.1118/1.4925866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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109
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Gao R, Wang H, Zhang Y, Mao R, Ren L, Yin F. SU-E-I-40: Phantom Research On Monochromatic Images Taken by Dual CBCT with Multiple Energy Sets. Med Phys 2015. [DOI: 10.1118/1.4924037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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110
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Gao XH, Gao R, Tian YZ, McGonigle P, Barrett JE, Dai Y, Hu H. A store-operated calcium channel inhibitor attenuates collagen-induced arthritis. Br J Pharmacol 2015; 172:2991-3002. [PMID: 25651822 DOI: 10.1111/bph.13104] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Revised: 01/20/2015] [Accepted: 01/27/2015] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND AND PURPOSE Store-operated calcium (SOC) channels are thought to play a critical role in immune responses, inflammatory diseases and chronic pain. The aim of this study was to explore the potential role and mechanisms of SOC channels in collagen-induced arthritis (CIA). EXPERIMENTAL APPROACH The CIA mouse model was used to examine the effects of the SOC channel inhibitor YM-58483 on CIA and arthritic pain. Hargreaves' and von Frey hair tests were conducted to measure thermal and mechanical sensitivities of hind paws. elisa was performed to measure cytokine production, and haematoxylin and eosin staining was used to assess knee histological changes. Western blot analysis was performed to examine protein levels. KEY RESULTS Pretreatment with 5 or 10 mg · kg(-1) of YM-58483 reduced the incidence of CIA, prevented the development of inflammation and pain hypersensitivity and other signs and features of arthritis disease. Similarly, treatment with YM-58483 after the onset of CIA: (i) reversed the clinical scores; (ii) reduced paw oedema; (iii) attenuated mechanical and thermal hypersensitivity; (iv) improved spontaneous motor activity; (v) decreased periphery production of IL-1β, IL-6 and TNF-α; and (vi) reduced spinal activation of ERK and calmodulin-dependent PKII (CaMKIIα). CONCLUSIONS AND IMPLICATIONS This study provides the first evidence that inhibition of SOC entry prevents and relieves rheumatoid arthritis (RA) and arthritic pain. These effects are probably mediated by a reduction in cytokine levels in the periphery and activation of ERK and CaMKIIα in the spinal cord. These results suggest that SOC channels are potential drug targets for the treatment of RA.
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Ma D, Fang Q, Wang P, Gao R, Sun J, Li Y, Hu XY, Wang JS. Downregulation of HO-1 promoted apoptosis induced by decitabine via increasing p15INK4B promoter demethylation in myelodysplastic syndrome. Gene Ther 2015; 22:287-96. [DOI: 10.1038/gt.2015.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 11/08/2014] [Accepted: 12/16/2014] [Indexed: 11/09/2022]
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Gao R, Ma D, Wang P, Sun J, Wang J, Fang Q. Role of heme oxygenase-1 in demethylating effects on SKM-1 cells induced by decitabine. GENETICS AND MOLECULAR RESEARCH 2015; 14:17788-98. [DOI: 10.4238/2015.december.22.3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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113
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Yu X, Hao W, Xie G, Wang Y, Gao R. Clone, purification and characterization of thermostable aminopeptidase ST1737 from Sulfolobus tokodaii. Chem Res Chin Univ 2014. [DOI: 10.1007/s40242-014-4314-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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114
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Boyle MJ, Gao R, Frampton CMA, Coleman B. Removal of the syndesmotic screw after the surgical treatment of a fracture of the ankle in adult patients does not affect one-year outcomes. Bone Joint J 2014; 96-B:1699-705. [DOI: 10.1302/0301-620x.96b12.34258] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Our aim was to compare the one-year post-operative outcomes following retention or removal of syndesmotic screws in adult patients with a fracture of the ankle that was treated surgically. A total of 51 patients (35 males, 16 females), with a mean age of 33.5 years (16 to 62), undergoing fibular osteosynthesis and syndesmotic screw fixation, were randomly allocated to retention of the syndesmotic screw or removal at three months post-operatively. The two groups were comparable at baseline. One year post-operatively, there was no significant difference in the mean Olerud–Molander ankle score (82.4 retention vs 86.7 removal, p = 0.367), the mean American Orthopedic Foot and Ankle Society ankle-hindfoot score (88.6 vs 90.1, p = 0.688), the mean American Academy of Orthopedic Surgeons foot and ankle score (96.3 vs 94.0, p = 0.250), the mean visual analogue pain score (1.0 vs 0.7, p = 0.237), the mean active dorsiflexion (10.2° vs 13.0°, p = 0.194) and plantar flexion (33.6° vs 31.3°, p = 0.503) of the ankle, or the mean radiological tibiofibular clear space (5.0 mm vs 5.3 mm, p = 0.276) between the two groups. A total of 19 patients (76%) in the retention group had a loose and/or broken screw one year post-operatively. We conclude that removal of a syndesmotic screw produces no significant functional, clinical or radiological benefit in adult patients who are treated surgically for a fracture of the ankle. Cite this article: Bone Joint J 2014;96-B:1699–1705.
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Gao R, Jiang Y, Zhao Y. Magnetic field sensor based on anti-resonant reflecting guidance in the magnetic gel-coated hollow core fiber. OPTICS LETTERS 2014; 39:6293-6296. [PMID: 25361337 DOI: 10.1364/ol.39.006293] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A compact all-fiber magnetic field sensor based on the magnetic gel coated hollow core fiber (HCF) has been proposed and experimentally demonstrated. A double-layered Fabry-Perot resonator is formed by coating a magnetic gel layer on the surface of the HCF. Anti-resonant reflecting guidance of light can be achieved in the HCF, and leaky mode is induced at resonant wavelength of the double-layered Fabry-Perot resonator, which results in lossy dips in the transmission spectrum of the HCF. Due to the tunable magneto-elastic effect, the shape of the magnetic gel is deformed with the external magnetic field, which results in a change of the resonate condition for the double-layered Fabry-Perot resonator. The magnetic field can be measured by interrogating the wavelength of the lossy dip. The experimental results show that a magnetic field sensitivity of 245 pm/Oe is achieved.
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Wijns W, Steg PG, Mauri L, Kurowski V, Parikh K, Gao R, Bode C, Greenwood JP, Lipsic E, Alamgir F, Rademaker-Havinga T, Boersma E, Radke P, van Leeuwen F, Camenzind E. Endeavour zotarolimus-eluting stent reduces stent thrombosis and improves clinical outcomes compared with cypher sirolimus-eluting stent: 4-year results of the PROTECT randomized trial. Eur Heart J 2014; 35:2812-20. [DOI: 10.1093/eurheartj/ehu318] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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Guo L, Gao R, Xu J, Jin L, Cotrim AP, Yan X, Zheng C, Goldsmith CM, Shan Z, Hai B, Zhou J, Zhang C, Baum BJ, Wang S. AdLTR2EF1α-FGF2-mediated prevention of fractionated irradiation-induced salivary hypofunction in swine. Gene Ther 2014; 21:866-73. [PMID: 25030610 DOI: 10.1038/gt.2014.63] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Revised: 04/26/2014] [Accepted: 06/06/2014] [Indexed: 12/16/2022]
Abstract
Patients frequently experience a loss of salivary function following irradiation (IR) for the treatment of an oral cavity and oropharyngeal cancer. Herein, we tested if transfer of fibroblast growth factor-2 (FGF2) cDNA could limit salivary dysfunction after fractionated IR (7.5 or 9 Gy for 5 consecutive days to one parotid gland) in the miniature pig (minipig). Parotid salivary flow rates steadily decreased by 16 weeks post-IR, whereas blood flow in the targeted parotid gland began to decrease ~3 days after beginning IR. By 2 weeks, post-IR salivary blood flow was reduced by 50%, at which point it remained stable for the remainder of the study. The single preadministration of a hybrid serotype 5 adenoviral vector encoding FGF2 (AdLTR2EF1a-FGF2) resulted in the protection of parotid microvascular endothelial cells from IR damage and significantly limited the decline of parotid salivary flow. Our results suggest that a local treatment directed at protecting salivary gland endothelial cells may be beneficial for patients undergoing IR for oral cavity and oropharyngeal cancer.
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Middleton S, Pither C, Gao R, Duncan S, Green J, Sharkey L, Chukualim B, Kratzing C, Woodward J, Gabe S, Jamieson N, Butler A. Adult Small Intestinal and Multivisceral Transplantation: Lessons Through the “Retrospecto-scope” at a Single UK Centre From 1991 to 2013. Transplant Proc 2014; 46:2114-8. [DOI: 10.1016/j.transproceed.2014.06.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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119
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Pither C, Green J, Butler A, Chukaulim B, West S, Gao R, Gabe S, Middleton S. Psychiatric Disorders in Patients Undergoing Intestinal Transplantation. Transplant Proc 2014; 46:2136-9. [DOI: 10.1016/j.transproceed.2014.06.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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120
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Gao R, Jiang Y, Jiang L. Multi-phase-shifted helical long period fiber grating based temperature-insensitive optical twist sensor. OPTICS EXPRESS 2014; 22:15697-15709. [PMID: 24977829 DOI: 10.1364/oe.22.015697] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A compact temperature-insensitive optical fiber twist sensor based on multi-phase-shifted helical long period fiber grating has been proposed and experimentally demonstrated in this paper. A multi-phase-shifted helical long period fiber grating is fabricated with a multi-period rotation technology. A π/2 and a 3π/2 phase shift is introduced in the helical long period fiber grating by changing the period. The helical pitch can be effectively changed with a different twist rate, which is measured by calculating the wavelength difference between two phase shift peaks. Although the wavelength of the phase shift peak also shifts with a change of the temperature, the wavelength difference between two phase shift peaks is constant due to two fixed phase shifts in the helical long period fiber grating, which is extremely insensitive to temperature change for the multi-phase-shifted helical long period fiber grating. The experimental results show that a sensitivity of up to 1.959 nm/(rad/m) is achieved.
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Wang D, Yang L, Gao R, Zhang X, Tan Y, Wu A, Zhu W, Zhou J, Zou S, Li X, Sun Y, Zhang Y, Liu Y, Liu T, Xiong Y, Xu J, Chen L, Weng Y, Qi X, Guo J, Li X, Dong J, Huang W, Zhang Y, Dong L, Zhao X, Liu L, Lu J, Lan Y, Wei H, Xin L, Chen Y, Xu C, Chen T, Zhu Y, Jiang T, Feng Z, Yang W, Wang Y, Zhu H, Guan Y, Gao GF, Li D, Han J, Wang S, Wu G, Shu Y. Genetic tuning of the novel avian influenza A(H7N9) virus during interspecies transmission, China, 2013. ACTA ACUST UNITED AC 2014; 19. [PMID: 24993557 DOI: 10.2807/1560-7917.es2014.19.25.20836] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A novel avian influenza A(H7N9) virus causing human infection emerged in February 2013 in China. To elucidate the mechanism of interspecies transmission, we compared the signature amino acids of avian influenza A(H7N9) viruses from human and non-human hosts and analysed the reassortants of 146 influenza A(H7N9) viruses with full genome sequences. We propose a genetic tuning procedure with continuous amino acid substitutions and reassorting that mediates host adaptation and interspecies transmission. When the early influenza A(H7N9) virus, containing ancestor haemagglutinin (HA) and neuraminidase (NA) genes similar to A/Shanghai/05 virus, circulated in waterfowl and transmitted to terrestrial poultry, it acquired an NA stalk deletion at amino acid positions 69 to 73. Then, receptor binding preference was tuned to increase the affinity to human-like receptors through HA G186V and Q226L mutations in terrestrial poultry. Additional mammalian adaptations such as PB2 E627K were selected in humans. The continual reassortation between H7N9 and H9N2 viruses resulted in multiple genotypes for further host adaptation. When we analysed a potential association of mutations and reassortants with clinical outcome, only the PB2 E627K mutation slightly increased the case fatality rate. Genetic tuning may create opportunities for further adaptation of influenza A(H7N9) and its potential to cause a pandemic.
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Zhang J, Gao R, Cao P, Yuan W. Additive effects of antiresorptive agents and exercise on lumbar spine bone mineral density in adults with low bone mass: a meta-analysis. Osteoporos Int 2014; 25:1585-94. [PMID: 24566585 DOI: 10.1007/s00198-014-2644-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Accepted: 11/26/2013] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Exercise has been recommended to increase bone mass and prevent osteoporosis. While current treatment of osteoporosis mainly involves the use of antiresorptive agents, it is unclear whether there are any additive effects in improving bone mass when antiresorptive agents and exercise are jointly used. METHODS A structured and comprehensive search of databases was undertaken along with hand searching of key journals and reference lists. The combined interventions of antiresorptive agents and exercise were examined for their additive effects on lumbar spine bone mineral density (BMD) among adults with low bone mass. Trial quality was assessed using the Jadad quality score. Study outcomes for analysis, absolute change (grams per square centimeter) or relative change (in percent) in BMD, at the lumbar spine were compared by calculating standardized mean difference (SMD) using fixed and random effect models. RESULTS Seven randomized controlled trials (RCT) met the predetermined inclusion criteria. The increase in lumbar spine BMD of the combined-intervention group was significantly greater than that of the antiresorptive agent-alone group (fixed effect model: SMD = 0.55; 95% confidence interval (CI) = 0.36, 0.75; overall effect Z-value = 5.51; p < 0.00001). Subgroup analyses also showed consistent results. Methodological quality of most included studies was scored 3 by the Jadad criterion, and publication bias was slight according to funnel plots. CONCLUSION It was found that combining antiresorptive agents with exercise had additive effects on improving lumbar spine bone mass gains in adults with low bone mass. To verify the additive effects further, more RCTs with longer duration and larger sample sizes are needed.
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Kong F, Wang Y, Cao S, Gao R, Xie G. Cloning, purification and characterization of a thermostable β-galactosidase from Thermotoga naphthophila RUK-10. Process Biochem 2014. [DOI: 10.1016/j.procbio.2014.02.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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124
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Lu D, Xie G, Gao R. Cloning, purification, and characterization of inorganic pyrophosphatase from the hyperthermophilic archaea Pyrococcus horikoshii. Protein Expr Purif 2014; 99:94-8. [PMID: 24755063 DOI: 10.1016/j.pep.2014.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 04/09/2014] [Accepted: 04/11/2014] [Indexed: 11/29/2022]
Abstract
The gene encoding inorganic pyrophosphatase (PPiase) from the hyperthermophilic archaea Pyrococcus horikoshii (Pho PPiase) was cloned in the Escherichia coli strain BL21/pET15b, and the recombinant PPiase was purified by Ni-chelating chromatography in only an one-step procedure. The PPiase showed optimal activity at 88°C and pH of 10.3. Kinetic analysis revealed Km, kcat, Vm of 14.27μM, 3436s(-1), and 34.35μmol/min/mg protein, respectively. Pho PPiase was stable against denaturant chemicals as well as heat. It retained 19.61% of the original activity after incubation at 100°C for 12h and 25.96% of the original activity in the presence of 8M urea after incubation at 50°C for 120h. Pho PPiase showed high specificity for inorganic pyrophosphate but low reactivity to sodium tripolyphosphate and sodium tetrapolyphosphate. ADP and ATP could not serve as substrates.
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Gao R, Du Y, Wang L, Nomura Y, Satar G, Gordon D, Gurevitz M, Goldin AL, Dong K. Sequence variations at I260 and A1731 contribute to persistent currents in Drosophila sodium channels. Neuroscience 2014; 268:297-308. [PMID: 24662849 DOI: 10.1016/j.neuroscience.2014.03.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 02/02/2014] [Accepted: 03/09/2014] [Indexed: 12/19/2022]
Abstract
Tetrodotoxin-sensitive persistent sodium currents, INaP, that activate at subthreshold voltages, have been detected in numerous vertebrate and invertebrate neurons. These currents are believed to be critical for regulating neuronal excitability. However, the molecular mechanism underlying INaP is controversial. In this study, we identified an INaP with a broad range of voltage dependence, from -60mV to 20mV, in a Drosophila sodium channel variant expressed in Xenopus oocytes. Mutational analysis revealed that two variant-specific amino acid changes, I260T in the S4-S5 linker of domain I (ILS4-S5) and A1731V in the voltage sensor S4 of domain IV (IVS4), contribute to the INaP. I260T is critical for the portion of INaP at hyperpolarized potentials. The T260-mediated INaP is likely the result of window currents flowing in the voltage range where the activation and inactivation curves overlap. A1731V is responsible for impaired inactivation and contributes to the portion of INaP at depolarized potentials. Furthermore, A1731V causes enhanced activity of two site-3 toxins which induce persistent currents by inhibiting the outward movement of IVS4, suggesting that A1731V inhibits the outward movement of IVS4. These results provided molecular evidence for the involvement of distinct mechanisms in the generation of INaP: T260 contributes to INaP via enhancement of the window current, whereas V1731 impairs fast inactivation probably by inhibiting the outward movement of IVS4.
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