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Ahmad QR, Allen RC, Andersen TC, Anglin JD, Barton JC, Beier EW, Bercovitch M, Bigu J, Biller SD, Black RA, Blevis I, Boardman RJ, Boger J, Bonvin E, Boulay MG, Bowler MG, Bowles TJ, Brice SJ, Browne MC, Bullard TV, Bühler G, Cameron J, Chan YD, Chen HH, Chen M, Chen X, Cleveland BT, Clifford ETH, Cowan JHM, Cowen DF, Cox GA, Dai X, Dalnoki-Veress F, Davidson WF, Doe PJ, Doucas G, Dragowsky MR, Duba CA, Duncan FA, Dunford M, Dunmore JA, Earle ED, Elliott SR, Evans HC, Ewan GT, Farine J, Fergani H, Ferraris AP, Ford RJ, Formaggio JA, Fowler MM, Frame K, Frank ED, Frati W, Gagnon N, Germani JV, Gil S, Graham K, Grant DR, Hahn RL, Hallin AL, Hallman ED, Hamer AS, Hamian AA, Handler WB, Haq RU, Hargrove CK, Harvey PJ, Hazama R, Heeger KM, Heintzelman WJ, Heise J, Helmer RL, Hepburn JD, Heron H, Hewett J, Hime A, Howe M, Hykawy JG, Isaac MCP, Jagam P, Jelley NA, Jillings C, Jonkmans G, Kazkaz K, Keener PT, Klein JR, Knox AB, Komar RJ, Kouzes R, Kutter T, Kyba CCM, Law J, Lawson IT, Lay M, Lee HW, Lesko KT, Leslie JR, Levine I, Locke W, Luoma S, Lyon J, Majerus S, Mak HB, Maneira J, Manor J, Marino AD, McCauley N, McDonald AB, McDonald DS, McFarlane K, McGregor G, Meijer Drees R, Mifflin C, Miller GG, Milton G, Moffat BA, Moorhead M, Nally CW, Neubauer MS, Newcomer FM, Ng HS, Noble AJ, Norman EB, Novikov VM, O'Neill M, Okada CE, Ollerhead RW, Omori M, Orrell JL, Oser SM, Poon AWP, Radcliffe TJ, Roberge A, Robertson BC, Robertson RGH, Rosendahl SSE, Rowley JK, Rusu VL, Saettler E, Schaffer KK, Schwendener MH, Schülke A, Seifert H, Shatkay M, Simpson JJ, Sims CJ, Sinclair D, Skensved P, Smith AR, Smith MWE, Spreitzer T, Starinsky N, Steiger TD, Stokstad RG, Stonehill LC, Storey RS, Sur B, Tafirout R, Tagg N, Tanner NW, Taplin RK, Thorman M, Thornewell PM, Trent PT, Tserkovnyak YI, Van Berg R, Van de Water RG, Virtue CJ, Waltham CE, Wang JX, Wark DL, West N, Wilhelmy JB, Wilkerson JF, Wilson JR, Wittich P, Wouters JM, Yeh M. Measurement of day and night neutrino energy spectra at SNO and constraints on neutrino mixing parameters. PHYSICAL REVIEW LETTERS 2002; 89:011302. [PMID: 12097026 DOI: 10.1103/physrevlett.89.011302] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2002] [Indexed: 05/23/2023]
Abstract
The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted 8B spectrum, the night minus day rate is 14.0%+/-6.3%(+1.5%)(-1.4%) of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the nu(e) asymmetry is found to be 7.0%+/-4.9%(+1.3%)(-1.2%). A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution.
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Ahmad QR, Allen RC, Andersen TC, D Anglin J, Barton JC, Beier EW, Bercovitch M, Bigu J, Biller SD, Black RA, Blevis I, Boardman RJ, Boger J, Bonvin E, Boulay MG, Bowler MG, Bowles TJ, Brice SJ, Browne MC, Bullard TV, Bühler G, Cameron J, Chan YD, Chen HH, Chen M, Chen X, Cleveland BT, Clifford ETH, Cowan JHM, Cowen DF, Cox GA, Dai X, Dalnoki-Veress F, Davidson WF, Doe PJ, Doucas G, Dragowsky MR, Duba CA, Duncan FA, Dunford M, Dunmore JA, Earle ED, Elliott SR, Evans HC, Ewan GT, Farine J, Fergani H, Ferraris AP, Ford RJ, Formaggio JA, Fowler MM, Frame K, Frank ED, Frati W, Gagnon N, Germani JV, Gil S, Graham K, Grant DR, Hahn RL, Hallin AL, Hallman ED, Hamer AS, Hamian AA, Handler WB, Haq RU, Hargrove CK, Harvey PJ, Hazama R, Heeger KM, Heintzelman WJ, Heise J, Helmer RL, Hepburn JD, Heron H, Hewett J, Hime A, Howe M, Hykawy JG, Isaac MCP, Jagam P, Jelley NA, Jillings C, Jonkmans G, Kazkaz K, Keener PT, Klein JR, Knox AB, Komar RJ, Kouzes R, Kutter T, Kyba CCM, Law J, Lawson IT, Lay M, Lee HW, Lesko KT, Leslie JR, Levine I, Locke W, Luoma S, Lyon J, Majerus S, Mak HB, Maneira J, Manor J, Marino AD, McCauley N, McDonald AB, McDonald DS, McFarlane K, McGregor G, Meijer Drees R, Mifflin C, Miller GG, Milton G, Moffat BA, Moorhead M, Nally CW, Neubauer MS, Newcomer FM, Ng HS, Noble AJ, Norman EB, Novikov VM, O'Neill M, Okada CE, Ollerhead RW, Omori M, Orrell JL, Oser SM, Poon AWP, Radcliffe TJ, Roberge A, Robertson BC, Robertson RGH, Rosendahl SSE, Rowley JK, Rusu VL, Saettler E, Schaffer KK, Schwendener MH, Schülke A, Seifert H, Shatkay M, Simpson JJ, Sims CJ, Sinclair D, Skensved P, Smith AR, Smith MWE, Spreitzer T, Starinsky N, Steiger TD, Stokstad RG, Stonehill LC, Storey RS, Sur B, Tafirout R, Tagg N, Tanner NW, Taplin RK, Thorman M, Thornewell PM, Trent PT, Tserkovnyak YI, Van Berg R, Van de Water RG, Virtue CJ, Waltham CE, Wang JX, Wark DL, West N, Wilhelmy JB, Wilkerson JF, Wilson JR, Wittich P, Wouters JM, Yeh M. Direct evidence for neutrino flavor transformation from neutral-current interactions in the Sudbury Neutrino Observatory. PHYSICAL REVIEW LETTERS 2002; 89:011301. [PMID: 12097025 DOI: 10.1103/physrevlett.89.011301] [Citation(s) in RCA: 170] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2002] [Indexed: 05/23/2023]
Abstract
Observations of neutral-current nu interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current (NC), elastic scattering, and charged current reactions and assuming the standard 8B shape, the nu(e) component of the 8B solar flux is phis(e) = 1.76(+0.05)(-0.05)(stat)(+0.09)(-0.09)(syst) x 10(6) cm(-2) s(-1) for a kinetic energy threshold of 5 MeV. The non-nu(e) component is phi(mu)(tau) = 3.41(+0.45)(-0.45)(stat)(+0.48)(-0.45)(syst) x 10(6) cm(-2) s(-1), 5.3sigma greater than zero, providing strong evidence for solar nu(e) flavor transformation. The total flux measured with the NC reaction is phi(NC) = 5.09(+0.44)(-0.43)(stat)(+0.46)(-0.43)(syst) x 10(6) cm(-2) s(-1), consistent with solar models.
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Johnson RB, Gilbert JA, Cooper RC, Parsell DE, Stewart BA, Dai X, Nick TG, Streckfus CF, Butler RA, Boring JG. Effect of estrogen deficiency on skeletal and alveolar bone density in sheep. J Periodontol 2002; 73:383-91. [PMID: 11990439 DOI: 10.1902/jop.2002.73.4.383] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND This study provides a longitudinal assessment of changes in alveolar and skeletal bone mineral density (BMD) in ovariectomized animals. METHODS Following ovariectomy (OVX) (n = 6) or sham-operation (n = 6) intraoral radiographs were made at 4-month intervals and serum 17-beta-estradiol, osteocalcin, and interleukin (IL)-6, urinary deoxypyridinium, and salivary IL-6, deoxypyridinium, and osteocalcin concentrations were evaluated. Twelve months after surgery, animals were sacrificed and the mandible and radius/ulna removed. Bones were sectioned and radiographed. Mean BMD and cortical thicknesses were calculated from each region. RESULTS OVX animals had a progressive decrease in serum 17-beta-estradiol, increased serum osteocalcin and IL-6, urinary deoxypyridinium and salivary IL-6, osteocalcin and deoxypyridinium (P < 0.001), suggesting that they were becoming osteoporotic. The BMD of the radius/ulna and mandibular alveolar bone was significantly reduced in OVX animals (P < 0.05 and P < 0.001, respectively). Reduced alveolar bone BMD became evident in OVX animals 6 months after surgery and became more severe during the subsequent 6 months. Alveolar crestal height was also significantly reduced in OVX animals (P < 0.001). These biochemical and density changes preceded a significant reduction in serum 17-beta-estradiol, which occurred between 4 and 8 months following surgery. CONCLUSIONS Serial measurements of alveolar BMD predicts loss of skeletal BMD in OVX sheep. Changes in alveolar BMD precede estrogen deficiency, suggesting that early signs of reduced BMD may be detected in peri-menopausal women. The presence of biomarkers of bone metabolism within saliva and their correlation with reduced BMD suggests that saliva could be used as an adjunct screening method for assessment of skeletal bone density.
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204
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Dai X, Warren TH. Dioxygen activation by a neutral beta-diketiminato copper(I) ethylene complex. Chem Commun (Camb) 2001:1998-9. [PMID: 12240258 DOI: 10.1039/b105244f] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis and structure of two thermally stable neutral beta-diketiminato copper(I) olefin complexes are presented along with the structure of a Cu(II)2(mu-OH)2 dimer that results from the reaction of the Cu(I) ethylene complex with O2 via the proposed intermediacy of a Cu(III)2(mu-O)2 species.
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Wen Y, Dai X, Wang C, Li L, Fu F, Wang X, Tang X, Liu H, Hua C, Pan J. [A retrospective clinical study of 6539 cases of malignant oral-maxillofacial tumors]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2001; 19:296-9. [PMID: 12539484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE The aim of this study is to obtain the general information of post-operation malignant oral-maxillofacial tumor patients in forty-seven years. METHODS A total of 6539 patients with malignant oral-maxillofacial tumors in the hospital of stomatology, west china university of medical sciences, from 1953 to 2000 were retrospected. RESULTS The average age of patients with malignant oral-maxilloficial tumor is 48.7 years old. The ratio of male to female is 2.31:1. The most common original malignant tumors in this oral-maxillofacial region are malignant oral tumors, malignant maxillary tumors, malignant mandibular tumors, and malignant sialoma successively. As to the original tissues of tumors, there were 5869 cases of epithelial tumors, and made up 89.75% of all the investigated patients. Tumors came from lymphatic and hematopoietic systems and mesoderm were much less those came from epithelia. There were 4177 cases of squamous cell carcinomas and the percentage was 63.88%. CONCLUSION The incidence rate of malignant tumors in oral-maxillofacial region tends to increase, and the average age of patients also rose. The ratio of male to female decreases gradually. Epithelial tumors, especially squamous cell carcinomas are very common tumors happening in this region.
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Meng J, Dai X, Chang JC, Lopareva E, Pillot J, Fields HA, Khudyakov YE. Identification and characterization of the neutralization epitope(s) of the hepatitis E virus. Virology 2001; 288:203-11. [PMID: 11601892 DOI: 10.1006/viro.2001.1093] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The neutralization epitope(s) of the hepatitis E virus (HEV) was studied by an in vitro neutralization assay using antibodies obtained by immunization of mice with 51 overlapping 30-mer synthetic peptides spanning the region 221-660 amino acids (aa) of the HEV open reading frame 2 encoded protein (pORF2) and 31 overlapping recombinant proteins of different sizes derived from the entire pORF2 of the HEV Burma strain. Antibodies against synthetic peptides and short recombinant proteins of approximately 100 aa did not neutralize HEV, suggesting the HEV neutralization epitope(s) is conformation-dependent. However, one recombinant protein of approximately 400 aa in length comprising the pORF2 sequence at position 274-660 aa as well as all truncated derivatives of this protein containing region 452-617 aa elicited antibodies, demonstrating HEV neutralizing activity. These findings establish for the first time that the minimal size fragment, designated pB166, that can efficiently model the neutralization epitope(s) is 166 aa in length and is located at position 452-617 aa of the HEV pORF2. Additionally, antibodies against pB166 were found to cross-neutralize three different HEV genotypes, suggesting that a common neutralization epitope(s) may exist within the different HEV genotypes. Thus, recombinant proteins constructed in this study may be considered as potential candidates for the development of an HEV subunit vaccine as well as for the development of highly sensitive and specific diagnostic tests.
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Ahmad QR, Allen RC, Andersen TC, Anglin JD, Bühler G, Barton JC, Beier EW, Bercovitch M, Bigu J, Biller S, Black RA, Blevis I, Boardman RJ, Boger J, Bonvin E, Boulay MG, Bowler MG, Bowles TJ, Brice SJ, Browne MC, Bullard TV, Burritt TH, Cameron K, Cameron J, Chan YD, Chen M, Chen HH, Chen X, Chon MC, Cleveland BT, Clifford ET, Cowan JH, Cowen DF, Cox GA, Dai Y, Dai X, Dalnoki-Veress F, Davidson WF, Doe PJ, Doucas G, Dragowsky MR, Duba CA, Duncan FA, Dunmore J, Earle ED, Elliott SR, Evans HC, Ewan GT, Farine J, Fergani H, Ferraris AP, Ford RJ, Fowler MM, Frame K, Frank ED, Frati W, Germani JV, Gil S, Goldschmidt A, Grant DR, Hahn RL, Hallin AL, Hallman ED, Hamer A, Hamian AA, Haq RU, Hargrove CK, Harvey PJ, Hazama R, Heaton R, Heeger KM, Heintzelman WJ, Heise J, Helmer RL, Hepburn JD, Heron H, Hewett J, Hime A, Howe M, Hykawy JG, Isaac MC, Jagam P, Jelley NA, Jillings C, Jonkmans G, Karn J, Keener PT, Kirch K, Klein JR, Knox AB, Komar RJ, Kouzes R, Kutter T, Kyba CC, Law J, Lawson IT, Lay M, Lee HW, Lesko KT, Leslie JR, Levine I, Locke W, Lowry MM, Luoma S, Lyon J, Majerus S, Mak HB, Marino AD, McCauley N, McDonald AB, McDonald DS, McFarlane K, McGregor G, McLatchie W, Meijer Drees R, Mes H, Mifflin C, Miller GG, Milton G, Moffat BA, Moorhead M, Nally CW, Neubauer MS, Newcomer FM, Ng HS, Noble AJ, Norman EB, Novikov VM, O'Neill M, Okada CE, Ollerhead RW, Omori M, Orrell JL, Oser SM, Poon AW, Radcliffe TJ, Roberge A, Robertson BC, Robertson RG, Rowley JK, Rusu VL, Saettler E, Schaffer KK, Schuelke A, Schwendener MH, Seifert H, Shatkay M, Simpson JJ, Sinclair D, Skensved P, Smith AR, Smith MW, Starinsky N, Steiger TD, Stokstad RG, Storey RS, Sur B, Tafirout R, Tagg N, Tanner NW, Taplin RK, Thorman M, Thornewell P, Trent PT, Tserkovnyak YI, Van Berg R, Van de Water RG, Virtue CJ, Waltham CE, Wang JX, Wark DL, West N, Wilhelmy JB, Wilkerson JF, Wilson J, Wittich P, Wouters JM, Yeh M. Measurement of the rate of nu(e) + d --> p + p + e(-) interactions produced by (8)B solar neutrinos at the Sudbury Neutrino Observatory. PHYSICAL REVIEW LETTERS 2001; 87:071301. [PMID: 11497878 DOI: 10.1103/physrevlett.87.071301] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2001] [Indexed: 05/23/2023]
Abstract
Solar neutrinos from (8)B decay have been detected at the Sudbury Neutrino Observatory via the charged current (CC) reaction on deuterium and the elastic scattering (ES) of electrons. The flux of nu(e)'s is measured by the CC reaction rate to be straight phi(CC)(nu(e)) = 1.75 +/- 0.07(stat)(+0.12)(-0.11)(syst) +/- 0.05(theor) x 10(6) cm(-2) s(-1). Comparison of straight phi(CC)(nu(e)) to the Super-Kamiokande Collaboration's precision value of the flux inferred from the ES reaction yields a 3.3 sigma difference, assuming the systematic uncertainties are normally distributed, providing evidence of an active non- nu(e) component in the solar flux. The total flux of active 8B neutrinos is determined to be 5.44+/-0.99 x 10(6) cm(-2) s(-1).
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Dai X, Wang Y, Yang B, Zhou J. [Expression of otsA gene in tobacco and improvement stress tolerance]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 2001; 41:427-31. [PMID: 12552907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
The Escherichia coli trehalose-6-phosphate synthase gene(otsA) was engineered under the control of cauliflower mosaic virus regulatory sequences (CaMV35S) for expression in plants. OtsA gene was incorporated into the chromosome DNA by Agrobacterium-mediated transfer and expressed in Nicotiana tabacum. The otsA gene transgenic plant exhibited multiple phenotypic alteration: improved stunted growth and drought tolerance. The detached leaves from the transgenic plant, their water loss slower than that of the controls. Trehalose accumulated in transgenic plant was determined by HPLC suggest that synthesis of the sugar improving plant to stress tolerance.
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209
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Dai X, Ruan D, Chen J, Wang M, Cai L. The effects of lead on transient outward currents of acutely dissociated rat dorsal root ganglia. Brain Res 2001; 904:327-40. [PMID: 11406131 DOI: 10.1016/s0006-8993(01)02505-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The effects of Pb2+ on transient outward currents (TOCs) were investigated on rat dorsal root ganglia (DRG) neurons at postnatal days of 15 approximately 21, using the conventional whole-cell patch-clamp technique. In media-sized (35 approximately 40 microm) neurons and in the presence of 50 mM TEA, TOCs that preliminarly included an A-current (IA) and a D-current (ID), were clearly present and dominant. Application of Pb2+ lengthened the initial delay of TOCs and increased the onset-peak time in a concentration-dependent manner. The amplitudes of initial outward current peak were reduced with increasing Pb2+ concentrations. The inhibitory effects of Pb2+ on TOCs were reversible with 80 approximately 90% of current reversed in 2 approximately 10 min at 1 approximately 400 microM Pb2+. For the normalized activation curves fitted by a single Boltzmann equation under each condition, there was a shift to more depolarized voltages with increasing concentrations of Pb2+. The V1/2 and the slope factor (k) increased from 12.76+/-1.49 mV and 15.31+/-1.66 mV (n=10) under control condition to 39.91+/-5.44 mV (n=10, P<0.01) and 21.39+/-3.13 mV (n=10, P<0.05) at 400 microM Pb2+, respectively, indicating that Pb2+ decreased the activation of TOCs. For the normalized steady-state inactivation curves, the V1/2 and the k increased from -92.31+/-2.72 and 8.59+/-1.36 mV (n=10) to -55.65+/-3.67 (n=10, P<0.01) and 23.02+/-2.98 mV (n=10, P<0.01) at 400 microM Pb2+, respectively. The curves were shifted to more depolarized voltages by Pb2+, indicating that channels were less likely to be inactivated at higher concentrations of Pb2+ at any given potential. The fast (tf) and slow (ts) decay time-constants were both significantly increased by increasing concentrations of Pb2+ (n=10, P<0.05), indicating that Pb2+ increased the decay time-course of TOCs. These effects were concentration-dependent and partly reversible following washing. Ca2+ modulated the TOCs gating and might share same binding site with Pb2+, for which Ca2+ had very low affinity. In summary, the results demonstrated that Pb2+ was a dose- and voltage-dependent, and reversible blocker of TOCs in rat DRG neurons. After Pb2+ application, normal sensory physiology of DRG neurons was affected, and these neurons might display aberrant firing properties that resulted in abnormal sensations. This variation caused by Pb2+ could underlie the toxical modulation of sensory input to the central nervous system.
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210
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Goldman D, Hankin M, Li Z, Dai X, Ding J. Transgenic zebrafish for studying nervous system development and regeneration. Transgenic Res 2001; 10:21-33. [PMID: 11252380 DOI: 10.1023/a:1008998832552] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Alpha1 tubulin gene expression is induced in the developing and regenerating CNS of vertebrates. Therefore, alpha1 tubulin gene expression may serve as a good probe for mechanisms underlying CNS development and regeneration. One approach to identify these mechanisms is to work backwards from the genome. This requires identification of alpha1 tubulin DNA sequences that mediate its developmental and regeneration-dependent expression pattern. Therefore, we generated transgenic zebrafish harboring a fragment of the alpha1 tubulin gene driving green fluorescent protein expression (GFP). In these fish, and similar to the endogenous gene, transgene expression was dramatically induced in the developing and regenerating nervous system. Although transgene expression generally declined during maturation of the nervous system, robust GFP expression was maintained in progenitor cells in the retinal periphery, lining brain ventricles and surrounding the central canal of the spinal cord. When these cells were cultured in vitro they divided and gave rise to new neurons. We also show that optic nerve crush in adult fish re-induced transgene expression in retinal ganglion cells. These studies identified a relatively small region of the alpha1 tubulin promoter that mediates its regulated expression pattern in developing and adult fish. This promoter will be extremely useful to investigators interested in targeting gene expression to the developing or regenerating nervous system. As adult transgenic fish maintain transgene expression in neural progenitors, these fish also provide a valuable resource of labeled adult neural progenitor cells that can be studied in vivo or in vitro. Finally, these fish should provide a unique in vivo system for investigating mechanisms mediating CNS development and regeneration.
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Wang AC, Dai X, Luu B, Conrad DJ. Peroxisome proliferator-activated receptor-gamma regulates airway epithelial cell activation. Am J Respir Cell Mol Biol 2001; 24:688-93. [PMID: 11415933 DOI: 10.1165/ajrcmb.24.6.4376] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The peroxisome proliferator-activated receptors (PPARs) are nuclear hormone transcription factors that regulate genes associated with lipid and glucose metabolism. Recent evidence suggests that PPAR-gamma may also act as a negative immunomodulator. To investigate the potential role of PPAR-gamma in regulating airway inflammation, we characterized the expression and function of PPAR-gamma in airway epithelial cells. Airway epithelial cells constitutively express PPAR-gamma-specific messenger RNA and protein. Further, airway epithelial PPAR-gamma is inducible by interleukin (IL)-4 in NIH-A549 cells. Two PPAR-gamma agonists, the prostaglandin D2 metabolite 15-deoxy-(Delta)(12,14) prostaglandin J2 (15d-PGJ2) and a thiazolidinedione, ciglitazone, were used to study the effects of PPAR-gamma activation on airway epithelial cytokine expression. Activation of PPAR-gamma stimulated a PPAR-responsive reporter gene in a ligand-specific manner. In NIH-A549 cells, both ligands also blocked the cytokine-induced expression of the inducible form of nitric oxide synthase in a dose-dependent manner. In contrast, ciglitazone alone had a slight effect on cytokine-induced IL-8 secretion, but markedly inhibited IL-8 secretion from cells pretreated with IL-4. The demonstration of PPAR-gamma expression and function in airway epithelial cells expands the immunoregulatory role of PPARs and suggests a critical role for PPAR-gamma in antagonizing proinflammatory pathways in the airways.
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Zhou J, Yang B, Dai X. [Detection of trehalose in transgenic tobacco by HPLC with ELSD]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 2001; 41:378-80. [PMID: 12549096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
The E. coli trehase synthalose gene(otsA) was transferred into Nicotiana tabacum mediated by Agrobacterium, but the method for detecting low concentration of trehalose in transgenic plant was not available. The high performance liquid chromatograph(HPLC) with evaporative light-scatting detector(ELSD) using water: methyl cyanide(1:2.6 v/v) as mobile phase was established in this work. An ODS column Zorbax RX-SIL was employed. the trehalose detection limits of ELSD was 5 mg/L. From the linear relationship between the logarithm of trehalose concentration and the logarithm of peak area, it was shown there was 14.7 micrograms.(g FW)-1 in transgenic plant. The data strongly confirmed that trehalose was responsible for the improved stress tolerance of the tobacco.
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Dai X, Qu P, Dreyfus CF. Neuronal signals regulate neurotrophin expression in oligodendrocytes of the basal forebrain. Glia 2001; 34:234-9. [PMID: 11329185 DOI: 10.1002/glia.1057] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Previous studies suggest that oligodendrocytes express trophic molecules, including neurotrophins. These molecules have been shown to influence nearby neurons. To determine whether neuronal signals may, in turn, affect oligodendrocyte-derived trophins, we examined regulation of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) mRNA expression in cultured oligodendrocytes of the basal forebrain. Neuronal signals had distinct effects on individual neurotrophins. KCl elicited increases in BDNF mRNA, but did not affect expression of NGF or NT-3. The cholinergic agonist, carbachol, increased expression of NGF, but did not affect expression of BDNF or NT-3. Glutamate elicited a decrease in BDNF, but did not affect expression of NGF or NT-3. This glutamate effect is not due to toxicity, since the number of total cells was unchanged, while the number of mature myelin basic protein positive (MBP+) cells increased. Our observations suggest that individual neuronal signals distinctly influence the trophic function of oligodendrocytes.
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Hu S, Wu K, Yi H, Dai X, Cui D. Voltammetric determination of cadmium(II) using a chemically modified electrode. FRESENIUS' JOURNAL OF ANALYTICAL CHEMISTRY 2001; 370:101-3. [PMID: 11393227 DOI: 10.1007/s002160100700] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
An 1-(pyridylazo)-2-naphthol modified glassy carbon electrode has been investigated as sensor for the measurement of trace levels of Cd2+. Cd2+ is deposited on the surface of a PAN modified glassy carbon electrode at -1.10 V (vs. SCE) via forming Cd2+-PAN and subsequent reduction at the electrode. In the following step, Cd-PAN is oxidized, and voltammograms are recorded by scanning the potential in a positive direction. Calibration plots were found to be linear in the range 2 x 10(-8) mol/L to 8 x 10(-7) mol/L. The detection limit was 5 x 10(-10) mol/L, and the coefficient of variation, determined on one single electrode at a concentration of 5 x 10(-7) mol/L, was calculated to be 3.2% (n = 5). Using this new kind of modified electrode, trace levels of Cd(II) in water samples were determined; the average recovery was calculated to be 98.78%.
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Wen T, Ming D, Dai X, Dai J, Evenson WE. Type of inversion problem in physics: an inverse emissivity problem. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 63:045601. [PMID: 11308905 DOI: 10.1103/physreve.63.045601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2000] [Indexed: 05/23/2023]
Abstract
Inversion problems have recently drawn vast amounts of attention from the physics community due to their potential widespread applications. In this Rapid Communication, a different type of inversion problem in physics is proposed: an inverse emissivity problem, which aims to determine the emissivity g(nu) by measuring only the total radiated power J(T). Like other inverse problems, this one has potential for important practical applications. An exact solution is obtained for the proposed inverse problem. A unique existence theorem and techniques for eliminating divergences are also presented. A universal function set (UFS) suggested for numerical calculations is shown to be very useful in a numerical example. The UFS makes this inversion method practical and convenient for realistic calculations.
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McCrae RR, Yang J, Costa PT, Dai X, Yao S, Cai T, Gao B. Personality profiles and the prediction of categorical personality disorders. J Pers 2001; 69:155-74. [PMID: 11339794 DOI: 10.1111/1467-6494.00140] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Personality disorders (PDs) are usually construed as psychiatric categories characterized by a unique configuration of traits and behaviors. To generate clinical hypotheses from normal personality trait scores, profile agreement statistics can be calculated using a prototypical personality profile for each PD. Multimethod data from 1,909 psychiatric patients in the People's Republic of China were used to examine the accuracy of such hypotheses in the Interpretive Report of the Revised NEO Personality Inventory. Profile agreement indices from both self-reports and spouse ratings were significantly related to PD symptom scores derived from questionnaires and clinical interviews. However, accuracy of diagnostic classification was only modest to moderate, probably because PDs are not discrete categorical entities. Together with other literature, these data suggest that the current categorical system should be replaced by a more comprehensive system of personality traits and personality-related problems.
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Ariza X, Pineda O, Vilarrasa J, Shipps GW, Ma Y, Dai X. Bocdene and Mocdene Derivatives of Catechols and Catecholamines. Org Lett 2001; 3:1399-401. [PMID: 11348244 DOI: 10.1021/ol015754c] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction in text] Catechols react chemoselectively, in the presence of either alcohols, 1,2-diols, or simple phenols, with tert-butyl propynoate and with methyl propynoate to give 2-Boc-ethylidene (Bocdene) and 2-Moc-ethylidene (Mocdene) acetals, respectively, in 96-100% yields within 30 min at room temperature, provided that 150 mol % of DMAP is added. Cleavage of these acetals with pyrrolidine readily takes place (at room temperature!) in 95-100% yields. By taking advantage of the features of Bocdene acetals, novel catecholamine-related phosphate mimetics have been prepared.
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Dai X, Zhang T, He D, Zhang X. MIMO system invertibility and decoupling control strategies based on ANN αth-order inversion. ACTA ACUST UNITED AC 2001. [DOI: 10.1049/ip-cta:20010283] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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219
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Zhang J, Xie Y, Dai X, Wei W. Monitoring of Lactobacillus fermentation process by using ion chromatography with a series piezoelectric quartz crystal detector. J Microbiol Methods 2001; 44:105-11. [PMID: 11165339 DOI: 10.1016/s0167-7012(00)00238-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A new method monitoring Lactobacillus fermentation process, which combines ion chromatography (IC) with a series piezoelectric quartz crystal (SPQC) technique, is presented in this paper. Monitoring of the fermentation process was realized by examining the rate of production of lactic acid. An automatic membrane dialyser was used for the pretreatment of the sample in on-line monitoring. A mixture of p-hydroxybenzoic acid and N,N-diethylethanolamine was adopted as mobile phase and its flow rate was 0.8 ml/min. The effects of some fermentation conditions were also discussed in detail. Accordingly, the optimal fermentation conditions were obtained. This method is simple and convenient while the results obtained are accurate and reliable.
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220
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Xiao H, Dai X, Mao X. [Inhibition of voltage-activated outward delayed rectifier potassium channel currents in dorsal root ganglion neurons of rats by lead]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 2001; 35:108-10. [PMID: 11413681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
OBJECTIVE To study the effect of lead on voltage-activated outward delayed rectifier potassium channel currents in acute isolated dorsal root ganglion (DRG) neurons of adult rats. METHODS Patch clamp technique was employed to record the whole cell of DRG in adult rats. RESULTS In the experiments, delayed rectifier (IK) potassium currents channel was recorded and activation was voltage-dependent. The threshold concentration of lead (Pb2+) for IK was 1 mumol/L, which reduced potassium current by (8.6 +/- 0.8)%, 4 mumol/L of Pb2+ reduced the current by (38.6 +/- 6.2)%, and 8 mumol/L of Pb2+ reduced the current by (63.0 +/- 5.1)%. The action of lead was rapid and its effect would be reversed rapidly to various extent by washing. CONCLUSION Higher outward delayed rectifier potassium channel currents, which could be reversed.
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Yang J, McCrae RR, Costa PT, Yao S, Dai X, Cai T, Gao B. The cross-cultural generalizability of Axis-II constructs: an evaluation of two personality disorder assessment instruments in the People's Republic of China. J Pers Disord 2001; 14:249-63. [PMID: 11019748 DOI: 10.1521/pedi.2000.14.3.249] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We examined the reliability, cross-instrument validity, and factor structure of Chinese adaptations of the Personality Diagnostic Questionnaire (PDQ-4+; N = 1,926) and Personality Disorders Interview (PDI-IV; N = 525) in psychiatric patients. Comparisons with data from Western countries suggest that the psychometric properties of these two instruments are comparable across cultures. Low to modest agreement between the PDQ-4+ and PDI-IV was observed for both dimensional and categorical personality disorder evaluations. When the PDI-IV was used as the diagnostic standard, the PDQ-4+ showed higher sensitivity than specificity, and higher negative predictive power than positive predictive power. Factor analyses of both instruments replicated the four-factor structure O'Connor and Dyce (1998) found in Western samples. Results suggested that conceptions and measures of DSM-IV personality disorders are cross-culturally generalizable to Chinese psychiatric populations.
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Streckfus C, Bigler L, Dellinger T, Dai X, Cox WJ, McArthur A, Kingman A, Thigpen JT. Reliability assessment of soluble c-erbB-2 concentrations in the saliva of healthy women and men. ORAL SURGERY, ORAL MEDICINE, ORAL PATHOLOGY, ORAL RADIOLOGY, AND ENDODONTICS 2001; 91:174-9. [PMID: 11174594 DOI: 10.1067/moe.2001.111758] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND The protein c-erb B-2, also known as Her2/neu, is a prognostic breast cancer marker assayed in tissue biopsy specimens from women diagnosed with malignant tumors. Current studies suggest that soluble fragments of the c-erb B-2 oncogene may be released from the cell surface and become detectable in patients with a carcinoma of the breast. Consequently, the purpose of this study is to assay soluble c-erb B-2 protein in the saliva of healthy men and women to determine the reliability of the assay. METHODS To determine the diagnostic utility of this oncogene, we assayed the soluble form of the c-erb B-2 protein in the saliva with an enzyme-linked immunosorbent assay. The study population consisted of 10 healthy women and 9 healthy men who were serially sampled for saliva 3 times a day for a 5-day period. Saliva was collected from each subject at 9 AM, 4 PM, and 9 PM during the 5-day period. RESULTS We found the presence of c-erb B-2 protein in the saliva of both groups of subjects. The salivary levels of c-erb B-2 were not significantly different when compared for gender differences. Likewise, the results suggest that sampling during various times of the day for salivary c-erb B-2 levels has no effect on marker concentration. Reliability analyses showed that supervised salivary collections were more reliable than unsupervised collections. CONCLUSIONS The results of this pilot study suggest that the assay for salivary c-erb B-2 protein is reliable and might have potential use in the initial detection and follow-up screening for the recurrence of breast cancer in both men and women.
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Valantine H, Zhu D, Wen P, Panchal SN, Dai X. Impact of type 1 diabetes on microvascular vs. macrovascular involvement with TXCAD: is there a difference in models of the disease? J Heart Lung Transplant 2001; 20:186-187. [PMID: 11250312 DOI: 10.1016/s1053-2498(00)00385-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Li L, Dai X, Liu Y, Clevenger JO, Field RW, Jeung GH, Geum N, Lyyra AM. The Predissociation of the 1(3)Sigma(-)(g) State of (7)Li(2). JOURNAL OF MOLECULAR SPECTROSCOPY 2001; 205:139-145. [PMID: 11148118 DOI: 10.1006/jmsp.2000.8247] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The predissociation of the 1(3)Sigma(-)(g) v >/= 10 levels of (7)Li(2) has been observed by pulsed and continuous-wave perturbation-facilitated optical-optical double-resonance spectroscopy (PFOODR). Our ab initio calculation shows that the inner wall of the 1(3)Sigma(-)(g) potential intersects the 1(3)Pi(g) repulsive potential at internuclear distance R = 2.00 Å. The predissociation is due to a DeltaS = 0, DeltaLambda = +/-1 rotational-electronic interaction with the repulsive 1(3)Pi(g) state. Copyright 2001 Academic Press.
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Dai X, Omori H, Okumura Y, Ando M, Oki H, Hashimoto N, Baba H. Bone grafting in cementless total hip replacement for congenital dysplasia of the hip. INTERNATIONAL ORTHOPAEDICS 2000; 24:260-3. [PMID: 11153454 PMCID: PMC3619901 DOI: 10.1007/s002640000133] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We reviewed 27 cementless primary total hip replacements in patients with osteoarthrosis secondary to congenital dysplasia of the hip. Autogenous bone grafting was used as augmentation. On average the follow-up period was 9 years. Two hips were revised and three acetabular components were considered loose. In hips with loose cups the average graft coverage was significantly greater than in stable hips. The use of a cementless acetabular component is encouraging for reconstruction, although extensive grafting should be avoided. Our study suggests that cementless reconstruction in dysplastic hips yields a satisfactory outcome.
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226
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Dai X, Xiang T, Ng TK, Su Z. Probing superconducting phase fluctuations from the current noise spectrum of pseudogapped metal-superconductor tunnel junctions. PHYSICAL REVIEW LETTERS 2000; 85:3009-3012. [PMID: 11005990 DOI: 10.1103/physrevlett.85.3009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2000] [Indexed: 05/23/2023]
Abstract
We study the current noise spectra of a tunnel junction of a metal with strong pairing phase fluctuation and a superconductor. It is shown that there is a characteristic peak in the noise spectrum at the intrinsic Josephson frequency omega(J) = 2eV when omega(J) is smaller than the pairing gap but larger than the pairing scattering rate. In the presence of an ac voltage, the tunneling current noise shows a series of characteristic peaks with increasing dc voltage. Experimental observation of these peaks will give direct evidence of the pair fluctuation in the normal state of high- T(c) superconductors and the pair decay rate can be estimated from the half width of the peaks.
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Wang Y, Dai X, Wang Y, Zhou J. [Cloning and expression of otsA gene in E. coli]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 2000; 40:470-4. [PMID: 12548756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
1.5 kb of otsA gene encoding trehalose synthase has been cloned by PCR amplification. The DNA fragment was ligated to multi-copy vector and transformed to otsBA deleted and otsA deficient strains of E. coli separately. The transformants exhibited growth as well as the otsBA+ wild type on medium containing 0.5 mol/L NaCl. Trehalose was synthesized and accumulated in the transformed cells under osmotic pressure, which was determined by thin layer chromatograph. The results confirmed that otsA gene was functionally expressed in the recipient strains. These studies suggested that engineering otsA gene and trehalose accumulation into crop plants may improve drought and salinity tolerance.
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228
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Wang C, Gao Q, Fu F, Wen Y, Dai X, Gong H, Lu X. [Treatment of hemangioma in oral and maxillofacial region with pingyangmycin injection]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2000; 18:317-9. [PMID: 12539650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To investigate the indication and result in hemangioma in oral and maxillofacial region with Pingyangmycin injection. METHODS 1282 patients (554 males and 728 females) with hemangioma in oral and maxillofacial region have been treated in our hospital during the 10-year period from May 1990 to March 1999. The patients range between 0.5-84 years old. Lip, cheek and tongue were usually involved. 1211 patients were treated with injection of Pingyangmycin(about 0.89 mg/ml) and dexamethasone (about 0.55 mg/ml), 1 time/1-2 weeks. RESULTS The curative rates of cavernous hemangioma and strawberry hemangioma were 93.87% and 84.90%, but that of plexiform hemangioma was 22.22% and those of portwine stain and central hemangioma of the jaws were 0%, respectively. Serious complications associated with Pingyangmycin injection, such as pulmonary fibrosis were not seen. CONCLUSION Injection of Pingyangmycin is selective primary method for cavernous and strawberry hemangioma treatment.
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Abstract
The Tetrahymena group I ribozyme was modified by replacing all 99 component uridine residues with 5-bromouridine. This resulted in a 13-fold reduction in catalytic efficiency in the RNA-catalyzed phosphoester-transfer reaction compared to the behavior of the unmodified ribozyme. A population of 10(13) variant ribozymes was constructed, each containing 5-bromouridine in place of uridine. Five successive 'generations' of in vitro evolution were carried out, selecting for improved phosphoester transferase activity. The evolved molecules exhibited a 27-fold increase in catalytic efficiency compared to the wild-type bromouridine-containing ribozyme, even exceeding that of the wild-type ribozyme in the non-brominated form. Three specific mutations were found to be responsible for this altered behavior. These mutations enhanced activity in the context of 5-bromouridine, but were detrimental in the context of unmodified uridine. The evolved RNAs not only tolerated but came to exploit the presence of the nucleotide analogue in carrying out their catalytic function.
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230
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Dai X, Omori H, Okumura Y, Ando M, Oki H, Hashimoto N, Baba H. Serial measurement of polyethylene wear of well-fixed cementless metal-backed acetabular component in total hip arthroplasty: an over 10 year follow-up study. Artif Organs 2000; 24:746-51. [PMID: 11012546 DOI: 10.1046/j.1525-1594.2000.06571-2.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Serial radiographic measurements of polyethylene wear were performed in 38 hips (33 patients) with primary cementless total hip arthroplasty (THA). The average follow-up period was 131.8 months. All prostheses were assessed as radiographically stable at the latest follow-up. A two-dimensional method was used to calculate the relative migration of the femoral head center to the cup center. The average total linear wear and wear rate were 1.22 mm and 0.11 mm/year, respectively. The degree of wear in the first 2 postoperative years accounted for nearly 40% of the total wear at the end of the study (average follow up: 131.8 +/- 10.0 months, +/-SD). The migration of the femoral head at an average period of 3. 4 months after operation accounted for 56% of the amount of wear in the first 2 years. Wear rate decreased gradually with time and stabilized after the fourth year. However, in 2 patients, a progressive increase in the wear rate was associated with severe osteolysis and failure of THA. Both creep and wear contributed to the femoral penetration into the polyethylene liner. The influence of creep cannot be ruled out, especially in the early period after operation. Polyethylene wear is a multifactorial process, and the study of individual wear patterns might be useful in identifying patients who are at risk of late failure of THA.
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Abstract
The Tetrahymena group I ribozyme was modified by replacing all 99 component uridine residues with 5-bromouridine. This resulted in a 13-fold reduction in catalytic efficiency in the RNA-catalyzed phosphoester-transfer reaction compared to the behavior of the unmodified ribozyme. A population of 10(13) variant ribozymes was constructed, each containing 5-bromouridine in place of uridine. Five successive 'generations' of in vitro evolution were carried out, selecting for improved phosphoester transferase activity. The evolved molecules exhibited a 27-fold increase in catalytic efficiency compared to the wild-type bromouridine-containing ribozyme, even exceeding that of the wild-type ribozyme in the non-brominated form. Three specific mutations were found to be responsible for this altered behavior. These mutations enhanced activity in the context of 5-bromouridine, but were detrimental in the context of unmodified uridine. The evolved RNAs not only tolerated but came to exploit the presence of the nucleotide analogue in carrying out their catalytic function.
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232
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Ming D, Wen T, Dai J, Dai X, Evenson WE. Exact solution of the specific-heat-phonon spectrum inversion from the Mobius inverse formula. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 2000; 62:R3019-22. [PMID: 11088868 DOI: 10.1103/physreve.62.r3019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2000] [Indexed: 11/06/2022]
Abstract
The application of the Mobius inversion formula to the specific-heat-phonon spectrum inversion problem (SPI) initially appeared promising [N.X. Chen, Phys. Rev. Lett. 64, 1193 (1990); J. Maddox, Nature (London) 344, 377 (1990)]. However, no one has previously been able to obtain the exact Debye spectrum with the correct cut-off factor and frequency dependence from the Mobius formula. The main difficulty arises from the fact that the Mobius function &mgr;(n) is not completely known for large n in practice. In this paper, some exact solutions of SPI are obtained by using the Mobius inversion formula, most importantly the Debye spectrum as a special case, and the problem of the unknown Mobius function &mgr;(n) for large n is avoided. It is shown that the Mobius inversion formula can be useful for exact solutions to spectral inversion problems.
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Zhang XL, Tsui IS, Yip CM, Fung AW, Wong DK, Dai X, Yang Y, Hackett J, Morris C. Salmonella enterica serovar typhi uses type IVB pili to enter human intestinal epithelial cells. Infect Immun 2000; 68:3067-73. [PMID: 10816445 PMCID: PMC97533 DOI: 10.1128/iai.68.6.3067-3073.2000] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
DNA sequencing upstream of the Salmonella enterica serovar Typhi pilV and rci genes previously identified in the ca. 118-kb major pathogenicity island (X.-L. Zhang, C. Morris, and J. Hackett, Gene 202:139-146, 1997) identified a further 10 pil genes apparently forming a pil operon. The product of the pilS gene, prePilS protein (a putative type IVB structural prepilin) was purified, and an anti-prePilS antiserum was raised in mice. Mutants of serovar Typhi either lacking the whole pil operon or with an insertion mutation in the pilS gene were constructed, as was a strain in which the pilN to pilV genes were driven by the tac promoter. The pil(+) strains synthesized type IVB pili, as judged by (i) visualization in the electron microscope of thin pili in culture supernatants of one such strain and (ii) the presence of PilS protein (smaller than the prePilS protein by removal of the leader peptide) on immunoblotting of material pelleted by high-speed centrifugation of either the culture supernatant or sonicates of pil(+) strains. Control pil mutants did not express the PilS protein. A pilS mutant of serovar Typhi entered human intestinal INT407 cells in culture to levels only 5 to 25% of those of the wild-type strain, and serovar Typhi entry was strongly inhibited by soluble prePilS protein (50% inhibition of entry at 1.4 microM prePilS).
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Streckfus C, Bigler L, Dellinger T, Dai X, Kingman A, Thigpen JT. The presence of soluble c-erbB-2 in saliva and serum among women with breast carcinoma: a preliminary study. Clin Cancer Res 2000; 6:2363-70. [PMID: 10873088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The protein c-erbB-2, also known as Her2/neu, is a prognostic breast cancer marker assayed in tissue biopsies from women diagnosed with malignant tumors. Present studies suggest that soluble fragments of the c-erbB-2 oncogene may be released from the cell surface and become detectable in patients with carcinoma of the breast. Consequently, the purpose of this study was to assay the c-erbB-2 protein in the saliva and serum of women with and without carcinoma of the breast and to determine whether the protein possesses any diagnostic value. To determine the diagnostic utility of this oncogene, the soluble form of the c-erbB-2 protein was assayed in the saliva and serum using ELISA in three different groups of women. The three groups consisted of 57 healthy women, 41 women with benign breast lesions, and 30 women diagnosed with breast cancer. To compare the relative diagnostic utility of the c-erbB-2 protein, CA 15-3 was also measured. The CA 15-3 measurements served as a "gold standard" by which to compare the c-erbB-2 protein's diagnostic effectiveness. We found c-erbB-2 protein in the saliva and serum of all three groups of women. The salivary and serological levels of c-erbB-2 in the cancer patients, however, were significantly higher (P < 0.001) than the salivary and serum levels of healthy controls and benign tumor patients. Additionally, the c-erbB-2 protein was found to be equal to or to surpass the ability of CA 15-3 to detect patients with carcinoma. The results of the pilot study suggest that the c-erbB-2 protein may have potential use in the initial detection and/or follow-up screening for the recurrence of breast cancer in women.
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Wang X, Xiao H, Dai X, Liu X, Yu X, Wu J. [Effects of phoxim and fenvalerate on TTX-S and TTX-R sodium channels in the DRG neurons of adult rat]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 2000; 34:136-9. [PMID: 11860918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To study the joint neurotoxic effects of phoxim (Pho) and fenvalerate (Fen) on tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) Na(+) currents in dorsal root ganglion (DRG) neurons of adult rat. METHODS Whole cell patch clamp technique was used to test the effects of Pho and Fen on TTX-S and TTX-R sodium currents in DRG neurons. RESULTS The inactivation of TTX-R sodium channel was obviously slowed down by Fen. The tau(Na) of peak currents at doses of 10, 50 and 100 micromol/L Fen and control groups were (8.10 +/- 2.41) ms, (11.78 +/- 2.76) ms, P < 0.01, (8.76 +/-1.94) ms, P < 0.05 and (6.41 +/- 1.32) ms respectively. The inactivation of TTX-R sodium channel tail currents was also significantly delayed by Fen. The tau(Na) of the tail currents at doses of 10, 50, 100 micromol/L Fen and control groups were 6.11 +/- 0.52 (P < 0.05), 7.82 +/- 0.82 (P < 0.05), 7.23 +/- 1.09 (P < 0.05) and (4.91 +/- 0.97) ms separately. As compared with TTX-R sodium channel, the TTX-S sodium channel was less responsive to Fen exposure, which only led to slowly decay TTX-S sodium tail currents. There was no any effect of Pho on the TTX-S and TTX-R sodium channels. The mixed treatment of a Pho and Fen did not show joint effect on the sodium currents. CONCLUSION Both the peak and tail currents are changed by Fen, however, Fen has more remarkable effects on TTX-R than on TTX-S sodium channel. The combined exposure to Pho and Fen shows no joint effect on the sodium channel.
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Yan Q, Pang Y, Yang J, Nong G, Ouyang X, Dai X. Characterization of the ecdysteroid UDP-glucosyltransferase gene of Spodoptera litura multinucleocapsid nucleopolyhedrovirus. CHINESE JOURNAL OF BIOTECHNOLOGY 2000; 15:113-9. [PMID: 10719631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The ecdysteroid UDP-glucosyltransferase (EGT) gene of Spodoptera litura multinucleocapsid nucleopolyhedrovirus (SpltMNPV), Guangzhouisolate was sequenced. The open reading frame of the gene is 1530 nucleotides long, encoding a putative protein of 509 amino acids with Mr of 58,500. The 5' noncoding region has a TATA box. A polyadenylation signal, AATAAA, is contained downstream of the translation stop codon. A putative signal peptide is present at the N-terminus of the protein. Homology comparison with other baculovirus egt genes showed that these genes are highly conserved. The SpltMNPV egt gene is closely related to that of Spodoptera littoralis nucleopolyhedrovirus (SliNPV) with the identities of 84% in nucleotide and 91% in amino acid, respectively. In this study, an alignment of amino acid sequences has been made and a tentative phylogenetic tree of twelve baculovirus egts is presented.
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Tang B, Zhou L, Chen X, Dai X, Peng Z. [Production and some properties of a thermophilic protease from Bacillus stearothermophilus WF146]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 2000; 40:188-92. [PMID: 12548943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
The factors affecting Bacillus stearothermophilus WF146 for thermophilic protease producing have been investigated, more than 600 units of enzyme in 1 mL of fermented culture could be achieved under suitable condition. The protease had a molecular weight around 34 kD estimated by SDS-PAGE, and functioned optimally at pH 8.0 and 80 degrees C, respectively. In addition, the enzyme exhibited high temperature tolerance and was stable at a wide range of pH, and Ca2+ played a key role for the stability of the enzyme. While the protease activity of the enzyme was strongly inhibited by PMSF, DFP and IAA, and was not affected by DTT.
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Dai X, Clevenger JO, Liu Y, Song M, Shang J, Chen D, Field RW, Li L. The 2(3)Delta(g) State of (7)Li(2). JOURNAL OF MOLECULAR SPECTROSCOPY 2000; 200:120-122. [PMID: 10662582 DOI: 10.1006/jmsp.1999.8033] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Using pulsed perturbation-facilitated optical-optical double resonance (PFOODR) spectroscopy, the 2(3)Delta(g) state of (7)Li(2) (electronic configuration (varsigma(g)2s) (4ddelta(g)), effective principal quantum number n* = 4.101) has been observed and assigned. Molecular constants and a RKR potential energy curve were obtained. The major molecular constants are Copyright 2000 Academic Press.
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Wang X, Dong W, Dai X, Wang A, Du J, Tao Z. Sorption and desorption of Eu and Yb on alumina: mechanisms and effect of fulvic acid. Appl Radiat Isot 2000; 52:165-73. [PMID: 10697722 DOI: 10.1016/s0969-8043(99)00133-5] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effects of pH, ionic strength and FA (fulvic acid) on the sorption and desorption of Eu(III) and Yb(III) on alumina were respectively investigated by using batch technique and radiotracers 152 + 154Eu and 169Yb. The distribution coefficients for sorption and desorption of Eu on alumina at pH 4.4, 4.6 and 5.7 in 1 mol/l NaCl solutions as a function of solid phase concentration were determined in the presence or absence of FA. The effects of pH, FA and ionic strength on the distribution coefficients for sorption and desorption of Yb on alumina were determined in 0.01-2.0 mol/l NaNO3. It was found that pH and FA influenced the sorption of Eu(III) and Yb(III) on alumina greatly. A surface hydrolysis model can satisfactorily and qualitatively explain the observations on bare alumina. The competition among the complexations of surface free hydroxyl groups, soluble and sorbed fulvic acids can satisfactorily and qualitatively explain the observations on the coated alumina.
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240
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Johnson RB, Zebrowski EJ, Dai X. Synergistic enhancement of collagenous protein synthesis by human gingival fibroblasts exposed to nifedipine and interleukin-1-beta in vitro. J Oral Pathol Med 2000; 29:8-12. [PMID: 10678710 DOI: 10.1034/j.1600-0714.2000.290102.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Gingival overgrowth commonly occurs coincident to therapy with calcium channel blockers. The biologic mechanism for this condition is unknown; however, many clinicians suggest that poor oral hygiene may contribute to development of the overgrowth. This study tests the hypothesis that collagenous protein synthesis by gingival fibroblasts is synergistically enhanced when they are exposed to both nifedipine (N) and the pro-inflammatory cytokine, interleukin-1-beta, a cytokine expressed in inflamed gingiva. Human gingival fibroblasts were isolated from biopsies of normal gingiva and cells separated into two groups. Group 1 was exposed to media containing 0, 5, 50, or 500 pg/ml IL-1-beta, or 10(-7) M N for 7 days; Group 2 was exposed to those concentrations of IL-1-beta +10(-7) M N. [3H]-proline was added to the medium for the final 24 h. Cells and matrix were harvested and radioactivity determined by liquid scintillation analysis. Means (d.p.m./10(3) cells) were compared by factorial ANOVA and Scheffé comparisons. Collagenous protein synthesis was significantly reduced by 5 pg/ml IL-1-beta +10(-7) M N and enhanced by 500 pg/ml IL-1-beta +10(-7) M N as compared to N or IL-1-beta alone. Thus, patients may be more susceptible to gingival overgrowth coincident to nifedipine therapy as a result of the synergistic enhancement of connective tissue synthesis by these agents.
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241
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Meng J, Cong M, Dai X, Pillot J, Purdy MA, Fields HA, Khudyakov YE. Primary structure of open reading frame 2 and 3 of the hepatitis E virus isolated from Morocco. J Med Virol 1999. [PMID: 9892396 DOI: 10.1002/(sici)1096-9071(199902)57:2<126::aid-jmv7>3.0.co;2-o] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The nucleotide sequence from position 5,014 to 7,186 of the hepatitis E virus (HEV) genome was determined using a set of 10 polymerase chain reaction (PCR) fragments amplified directly from a pool of fecal specimens obtained from patients with well-documented epidemic HEV infection in Morocco. This sequence contains the 3'-terminal region of open reading frame 1 (ORF1), full length ORF2 and ORF3, and a portion of the 3'-noncoding region. The HEV Morocco nucleotide sequence was compared with the corresponding sequences of 13 HEV strains. A region of ORF2 that overlaps with ORF3 was found to be the most conserved region of ORF2, whereas a protein segment encoded by this region was found to be the most variable. Theoretical RNA secondary structure analysis predicted that this region may be folded into a strong secondary structure that may constrain nucleotide sequence variability. In addition, the nucleotide sequence comparison revealed that the HEV Morocco sequence is most homologous to the sequences of the HEV Asian strains compared with the HEV Mexico, swine, and US strains. Phylogenetic analysis performed on the entire ORF2 and ORF3 sequences and on a small fragment of ORF2 allowed classification of the HEV Morocco strain together with a few other known African strains as a separate subtype within the Asian-African genotype.
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242
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Dai X, Xiang J, Liu Y, Li L. 8-10svarsigma, 8-10dvarsigma (1)Sigma(+)(g), and 10-15dpi (1)Pi(g) Rydberg States of Na(2). JOURNAL OF MOLECULAR SPECTROSCOPY 1999; 198:244-248. [PMID: 10547306 DOI: 10.1006/jmsp.1999.7973] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
With a sensitive space-charge-limited diode ionization detector, we studied 8-10svarsigma, 8-10dvarsigma (1)Sigma(+)(g), and 10-15dpi (1)Pi(g) Rydberg states of Na(2) and obtained their molecular constants for the first time. It is the first successful example of a diode ionization detector that is used in a pulsed OODR molecular spectroscopy experiment. Copyright 1999 Academic Press.
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243
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Dai X, Wang Y, Zhou J. [Sequence analysis of the mutated AOX2 promoter region in the Pichia pastoris]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 1999; 39:559-62. [PMID: 12555564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Spontaneous revertants of the AOX1-defective P. pastoris strain have been isolated, which were identified as phenotypically utilize methanol to grow as the wild type. The promoter region of the AOX2 gene from the revertant has been obtained by PCR amplification, and the DNA fragment is 1022 base pair in size. By the analysis of sequencing result and compared with the AOX2 gene sequences recorded in Gene Bank, two point mutations which at positions of -529 and -255(relative to the translation initiation codon) respectively, have been found. Since the positions are located in the AOX2 upstream repression sequences, the mutations may act interfere the repressor to combine with the functional sequences, and increase transcriptional activity. The above result implicated that the P. pastoris' ability to utilize methanol could be increased through modification the upper stream transcriptional regulation region in the AOX2 gene.
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Li J, Dai X, Yang H, Fu J. [Vector construction for embryonic stem cell gene targeting of site specific point mutation mouse coagulation factor IX gene]. ZHONGHUA YI XUE YI CHUAN XUE ZA ZHI = ZHONGHUA YIXUE YICHUANXUE ZAZHI = CHINESE JOURNAL OF MEDICAL GENETICS 1999; 16:356-9. [PMID: 10581342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
OBJECTIVE To construct the recombinant vectors for embryonic stem(ES) cell gene targeting which contain the mouse coagulation factor IX (F IX) gene modified by PCR site-directed mutagenesis. METHODS Three site specific point mutations were introduced into exon 8 of mouse F IX gene respectively. The replacement targeting vectors were constructed and transfected into ES cells. The drug-resistant cell clones were picked after drug selection. RESULTS The construction of targeting vectors was successful and several drug-resistant ES cell clones were gained. CONCLUSION The site specific point mutation system can modify human gene in vitro more accurately. It is useful in the setting up of animal models.
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Dai X, Chen H, Liu Y, Li J, Xiang J, Chen D, Li L, Jeung G. The 6svarsigma, 6dvarsigma, and 7dvarsigma Rydberg (1)Sigma(+)(g) States and Two Doubly Excited (1)Sigma(+)(g) States of Na(2). JOURNAL OF MOLECULAR SPECTROSCOPY 1999; 198:239-243. [PMID: 10547305 DOI: 10.1006/jmsp.1999.7968] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Five highly excited (1)Sigma(+)(g) states of Na(2) were observed for the first time by pulsed optical-optical double resonance (OODR) fluorescence excitation spectroscopy. Three of the five states are assigned to the 6svarsigma (1)Sigma(+)(g), 6dvarsigma (1)Sigma(+)(g), and 7dvarsigma (1)Sigma(+)(g) Rydberg states. The other two states are assigned to doubly excited (1)Sigma(+)(g) states. Copyright 1999 Academic Press.
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Yu Z, Zhuang Y, Dai X. [Clinical study on tangshen mixture in treating diabetic nephropathy]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 1999; 19:524-6. [PMID: 11783183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To investigate the effects of Tangshen Mixture (TSM) on the serum glucose, quantity of proteinuria per 24 h, hypercoagulative status and oxidative injury in patients with diabetic nephropathy (DN). METHODS Ninety-three patients with DN were randomly divided into treated group and control group. 48 patients in the former were treated with insulin and TSM, while the latter was treated with insulin alone. Before and after treatment, the levels of fasting blood glucose (FBG), 2 h after meal blood glucose (PBG), 24 h urinary albumin (24 h-pro), endothelin (ET), alpha-granule membrane glycoprotein-140 (GMP-140), erythrocyte superoxide dismutase (ESOD), lipid peroxidase (LPO) were measured. RESULTS After two months treatment, compared with the control group the levels of ET and GMP-140, LPO, and 24 h-pro lowered obviously (P < 0.01, P < 0.05), and the level of ESOD increased (P < 0.05) in the treated group, no obvious change was found in control grout after treatment. CONCLUSION TSM could improve the hypercoagulative status, alleviate the renal free radical disturbances, and reduce the urinary protein loss.
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Johnson RB, Streckfus CF, Dai X, Tucci MA. Protein recovery from several paper types used to collect gingival crevicular fluid. J Periodontal Res 1999; 34:283-9. [PMID: 10633882 DOI: 10.1111/j.1600-0765.1999.tb02255.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The purpose of this study was to compare the efficiency of protein elution from several types of gingival crevicular fluid (GCF) collection papers when the volume of the inoculated protein and the elution methods were constant. Various concentrations of bovine serum albumin (BSA) and 14C-BSA were placed onto strips of Whatman #1 [W1], Whatman 3 MM chromatographic [W3], Periopaper (ProFlow) [P] and Periopaper (Harco) [H], and recovered proteins measured following a non-optimized centrifugal elution technique. There were significant differences in % recovery of BSA and 14C-BSA from the papers, which was dependent on both the type of paper and the concentration of the inoculated protein; that is, proteins at the lowest concentrations were less efficiently eluted from GCF collection papers than those at higher concentrations. Equations for regression lines of elution efficiency were quadratic. Thus, our data suggest significant differences in the efficiency for elution of BSA from absorbent papers when the volume of the inoculated fluid and the elution technique were constant. Previous variable or conflicting experimental data between research groups may have resulted from incomplete elution of proteins from GCF collection papers, possibly due to entrapment within, or binding of GCF proteins to the paper.
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Johnson RB, Serio FG, Dai X. Vascular endothelial growth factors and progression of periodontal diseases. J Periodontol 1999; 70:848-52. [PMID: 10476891 DOI: 10.1902/jop.1999.70.8.848] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Tissues become hemorrhagic and edematous coincident to periodontal diseases; however, there is little information concerning the biologic mechanisms which may produce these changes. Vascular endothelial growth factor (VEGF) is a macromolecule which enhances blood vessel growth and permeability. However, there is no information concerning gingival VEGF concentrations within normal or diseased gingiva. The purpose of this study was to assess changes in gingival concentrations of VEGF during initiation and progression of periodontal diseases and compare them to changes in the number of blood vessel profiles and concentration of recognized markers of periodontal disease severity (interleukin-6[IL-6]). METHODS Normal (non-hemorrhagic gingiva adjacent to a < or =3 mm gingival sulcus) and inflamed gingiva (hemorrhagic gingiva adjacent to a < or =3 mm, 4 to 6 mm, or >6 mm periodontal pocket) were studied. VEGF and IL-6 concentrations were assessed by ELISA and the number of blood vessels determined by histomorphometric techniques. Data were placed into one of the following groups: < or =3 mm, normal; < or =3 mm, diseased; 4 to 6 mm, diseased; and >6 mm, diseased. These groups were compared by factorial ANOVA and Scheffe comparisons. In addition, groups were compared by simple and multiple regression and regression ANOVA to determine possible correlations between them. RESULTS VEGF and IL-6 concentrations were significantly lower within normal than within diseased gingiva. The number of blood vessel profiles and mean IL-6 concentrations were highest in diseased tissues adjacent to >6 mm sulci and were significantly correlated with sulcular depth (P <0.001). In contrast, VEGF concentrations were highest within diseased gingiva adjacent to 4 to 6 mm periodontal pockets (P <0.001) and were not correlated with sulcular depth. CONCLUSIONS VEGF may be a factor in initiation and progression of gingivitis to periodontitis, possibly by promoting expansion of the vascular network coincident to progression of the inflammation.
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Dai X, Shi X, Pang Y, Su D. Prevention of baculovirus-induced apoptosis of BTI-Tn-5B1-4 (Hi5) cells by the p35 gene of Trichoplusia ni multicapsid nucleopolyhedrovirus. J Gen Virol 1999; 80 ( Pt 7):1841-1845. [PMID: 10423154 DOI: 10.1099/0022-1317-80-7-1841] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A typical apoptosis of BTI-Tn-5B1-4 (Hi5) cells induced by Heliothis armigera single capsid nucleopolyhedrovirus (HaSNPV) infection was completely suppressed by coinfection with Trichoplusia ni multicapsid nucleopolyhedrovirus polyhedron-negative recombinant (TnMNPV-SVI- G) (OCC-) at a low multiplicity of infection (6.5 x 10(-2)). To determine whether TnMNPV p35 alone was sufficient to inhibit the apoptosis, two recombinant plasmids containing the early promoter of p35, or the very late promoter of TnMNPV polh were constructed to study p35 function by transient expression assay. It was shown that expression of p35 alone could partially prevent HaSNPV-induced apoptosis but did not facilitate HaSNPV replication in Hi5 cells. The data suggests that both P35 of TnMNPV and other unknown gene products are required for the suppression of apoptosis and facilitation of HaSNPV replication in Hi5 cells.
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Rothman-Denes LB, Dai X, Davydova E, Carter R, Kazmierczak K. Transcriptional regulation by DNA structural transitions and single-stranded DNA-binding proteins. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 1999; 63:63-73. [PMID: 10384271 DOI: 10.1101/sqb.1998.63.63] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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