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Dai X, Chan YC, So AC. Digital speckle correlation method based on wavelet-packet noise-reduction processing. APPLIED OPTICS 1999; 38:3474-3482. [PMID: 18319947 DOI: 10.1364/ao.38.003474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Despite the advantages of being highly sensitive and nondestructive, the digital speckle correlation method (DSCM) may have difficulties in detecting tiny defects such as delaminations in multilayer ceramic capacitors. This is because the presence of background noise always complicates the data processing. We present a new algorithm, which employs the wavelet-packet noise-reduction process together with the improved DSCM, to improve data processing. Both the computational error and the noise are shown to be reduced successfully by this new algorithm. The accuracy (or precision) of the improved DSCM is increased after operation of the wavelet-packet noise-reduction process. The most important feature of this new algorithm is that it can extract a small hillock signal from a large noisy background in a DSCM deformation result. This helps to save time in the detection of tiny defects, such as delamination, in a miniaturized electronic component.
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Yao S, Cai W, Dai X. [Neuroendocrine mechanisms of impact by experimental stress on plasma glucose level in STZ KM mice]. ZHONGHUA YI XUE ZA ZHI 1999; 79:332-4. [PMID: 11715470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
OBJECTIVE To explore the neuroendocrine mechanisms of effects by experimental stress on plasma glucose level in streptozotocin induced mice(STZ mice). METHODS Forty STZ mice were divided randomly into Group A (STZ mice, stress) and Group B (STZ mice, no stress), and 20 normal KM mice in Group C (normal mice, stress) and Group D (normal mice, no stress). Group A and Group C were exposed to multiple stressors (restrain, rotation, crowding) for 6 weeks. Before and after the experiment, blood glucose(BG) levels were measured. By the end of experiment, blood and hypothalamus samples were collected to measure plasma insulin(I) concentrations, insulin sensitivity index(ISI), plasma norepinphine(NE), epinphin(EPI) and beta endorphin(beta-EP) concentrations. RESULTS After stress, the BG levels significantly increased and I concentrations decreased in Group A. Group A showed a greater decrease of ISI than that in Group B. There was significant difference in plasma NE and EPI concentrations among groups, and Group A showed marked increase. There was no significant difference in beta-EP concentrations among groups. There were low to moderate correlations among these variables after stress. CONCLUSION The STZ mice likely have altered adrenergic sensitivity to stress, which might play a leading role in the neuroendocrine mechanism of hyperglycemia of STZ mice after stress. The beta-EP might participate in this process of regulating glucose metabolism.
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Abstract
Regulation of transcription occurs through complex interactions of RNA polymerase and accessory proteins with specific DNA sequences and with each other. The DNA template topology influences the interaction of RNA polymerase with the promoter and its response to repressors, activators and the intracellular milieu through the formation of altered DNA structures or of nucleoprotein complexes. Recent developments on the role of DNA structures in transcription regulation are discussed.
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254
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Dai X, Zhou Y, Yu X. [Effect of ginseng injection in treating congestive heart failure and its influence on thyroid hormones]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 1999; 19:209-11. [PMID: 11783267] [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 observe the effect of Ginseng injection on congestive heart failure (CHF) and its influence on thyroid hormones. METHODS Fifty-four Patients of CHF were divided into two groups. On the basis of conventional treatment of western medicine, the Ginseng injection was given to the treated group additionally. Blood level of triiodothyronine (T3), thyroxine (T4), reverse triiodothyronine (rT3) and thyroid stimulating hormone (TSH) of all patients were determined before and after treatment by radioimmunoassay. RESULTS There were significant difference between the treated group and the control group in cure rate and mean course of therapy. The levels of T3 and T4 of all patients were lower than those of the normal control before treatment, and rT3 were higher. Two weeks after treatment, T3 and T4 level in all patients increased significantly and rT3 level significantly decreased(P < 0.05, P < 0.01). CONCLUSION Ginseng injection has a good effect on patients with CHF. It also has regulatory effect on thyroid hormones.
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Abstract
Potential roles of trophins in the normal and injured spinal cord are largely undefined. However, a number of recent studies suggest that adult spinal cord expresses neurotrophin receptors and responds to the neurotrophins, brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3), particularly after injury. The data indicate that trophins may enhance regrowth after damage and may represent a new therapeutic approach to injury. Neurotrophins are reportedly present in the spinal cord, but the cellular localization is unknown. This information is critical to begin delineating mechanisms of actions. To approach this problem, we examined whether spinal cord glia express BDNF and NT3 in vivo and have begun to define cellular distribution. Specific antibodies directed against the neurotrophins were utilized to visualize neurotrophin protein. Initial studies indicated that small cells in the white matter of adult rat spinal cord express BDNF and NT3. Large neurotrophin-positive neurons were also identified in the ventral cord. To identify the neurotrophin-positive cells, co-localization studies were performed utilizing neurotrophin polyclonal antisera together with monoclonal antibodies directed against the astrocyte marker, glial fibrillary acidic protein (GFAP). In the white matter of adult spinal cord, GFAP-positive and GFAP-negative cells expressed BDNF and NT3. Our study suggests that astrocyte and non-astrocyte cells provide trophic support to the adult spinal cord.
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256
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Xiang J, Dai X, Peng S, Chen H, Liu Y, Li J, Chen D, Li L. [Spectroscopic study of the 1pig Rydberg states of Na2]. GUANG PU XUE YU GUANG PU FEN XI = GUANG PU 1999; 19:1-4. [PMID: 15818899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Six highly excited 1pig states of the Na2 molecule have been investigated by optical-optical double resonance (OODR) flourescence excitation spectroscopy. Absolute vibrational numberings are determined and molecular constants and RKR potential curves are obtained. The lowest 10 1pig states have been relabeled according to the hydrogenic nllambda characters of the Rydberg orbital and classified into core-penetrating and core-nonpenetrating Rydberg states.
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Xiang J, Dai X, Peng S, Liu Y, Shang J, Chen D, Li L. [The application of ion detection in the study of spectroscopy of Na2]. GUANG PU XUE YU GUANG PU FEN XI = GUANG PU 1999; 19:11-12. [PMID: 15818902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Ion detection technique has been successfully used in the study of Rydberg states of Na2 by pulse optical-optical double resonance. High-lying Rydberg states near ionization limit have been observed and high sensitive and high gain spectra have been obtained. This technique is very useful for molecular spectroscopy.
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Zeng J, Zheng D, Dai X. [Research on biotherapeuticeffect anticancerous remedies]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 1999; 19:59-61. [PMID: 11783262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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259
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Hieber V, Dai X, Foreman M, Goldman D. Induction of alpha1-tubulin gene expression during development and regeneration of the fish central nervous system. JOURNAL OF NEUROBIOLOGY 1998; 37:429-40. [PMID: 9828048 DOI: 10.1002/(sici)1097-4695(19981115)37:3<429::aid-neu8>3.0.co;2-n] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The alpha1- and alpha2-tubulin encoding genes were cloned from a goldfish genomic DNA library. alpha1- and alpha2-tubulin RNA expression was examined in developing and adult retinas. These studies demonstrated increased alpha1-tubulin RNA in presumptive ganglion cells that grow axons early in retinal development and in adult retinal ganglion cells whose optic axons had been damaged. The alpha2-tubulin RNA was undetectable in developing retina and constitutively expressed in adult retinal ganglion cells regardless of optic nerve crush. To determine if these changes in alpha1-tubulin RNA reflected changes in alpha1-tubulin promoter activity, we introduced into zebrafish embryos and adult goldfish retinal explants expression vectors harboring the alpha1-tubulin gene's promoter. These studies showed that the alpha1-tubulin promoter confers a developmentally regulated, neuron-restricted pattern of reporter gene expression in vivo and its activity is increased in adult retinal neurons induced to regenerate their axons. Promoter deletions defined regions of alpha1-tubulin DNA necessary for this pattern of expression. These results suggest that DNA sequences necessary for alpha1-tubulin gene induction during central nervous system development and regeneration are contained within the alpha1-tubulin gene's 5'-flanking DNA and that this promoter will be useful for identifying these elements and their DNA binding proteins.
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260
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Dai X, Schonbaum C, Degenstein L, Bai W, Mahowald A, Fuchs E. The ovo gene required for cuticle formation and oogenesis in flies is involved in hair formation and spermatogenesis in mice. Genes Dev 1998; 12:3452-63. [PMID: 9808631 PMCID: PMC317232 DOI: 10.1101/gad.12.21.3452] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/1998] [Accepted: 09/09/1998] [Indexed: 11/24/2022]
Abstract
The Drosophila svb/ovo gene gives rise to differentially expressed transcripts encoding a zinc finger protein. svb/ovo has two distinct genetic functions: shavenbaby (svb) is required for proper formation of extracellular projections that are produced by certain epidermal cells in late-stage differentiation; ovo is required for survival and differentiation of female germ cells. We cloned a mouse gene, movo1 encoding a nuclear transcription factor that is highly similar to its fly counterpart in its zinc-finger sequences. In mice, the gene is expressed in skin, where it localizes to the differentiating cells of epidermis and hair follicles, and in testes, where it is present in spermatocytes and spermatids. Using gene targeting, we show that movo1 is required for proper development of both hair and sperm. movo1(-/-) mice are small, produce aberrant hairs, and display hypogenitalism, with a reduced ability to reproduce. These mice also develop abnormalities in kidney, where movo1 is also expressed. Our findings reveal remarkable parallels between mice and flies in epidermal appendage formation and in germ-cell maturation. Furthermore, they uncover a phenotype similar to that of Bardet-Biedl syndrome, a human disorder that maps to the same locus as human ovo1.
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261
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Dai X, Kloster M, Rothman-Denes LB. Sequence-dependent extrusion of a small DNA hairpin at the N4 virion RNA polymerase promoters. J Mol Biol 1998; 283:43-58. [PMID: 9761672 DOI: 10.1006/jmbi.1998.2096] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bacteriophage N4 virion RNA polymerase promoters contain five to seven-base inverted repeats separated by three bases and centered at position -12 from the site of transcription initiation. We have previously shown that these inverted repeats extrude as hairpins at physiological superhelical densities in a Mg(II)-dependent manner. Mg(II)-dependent hairpin extrusion at promoters P1 and P2 displays quantitative differences in reactivity to structural probes at different DNA superhelical densities, with extrusion at P2 being more favored at low superhelical density. Analyses of mutant promoters using structure-specific probes revealed that specific sequences, at the closing base-pair of the hairpin and at the loop (i.e. 5'-C-GXA-G-3' where X=G, A, T), are required for extrusion of the small promoter hairpins at physiological superhelical density. The sequence-dependent requirements for extrusion of the small N4 promoter hairpins may be generally applicable for other such sequences found both in prokaryotic and eukaryotic genomes.
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262
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Wang H, Sui X, Li J, Dai X, Ma D. [Isolation and identification of Agrobacterium spp. from cherry crown galls and their sensitivities to agrocin 84]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 1998; 38:381-5. [PMID: 12549403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Crown galls were sampled from cherry yards of Shandong, Hebei, and Liaoning provinces. 46 pathogenic strains were isolated. Physiological and biochemical tests revealed that 4 strains were Agrobacterium tumefaciens(bio. 1) and that the other 42 strains were A. rhizogenes (bio. 2), according to the classifications and nomenclatures of the genus Agrobacterium and the species revised by Sawada et al and Bouzar. The Ti plasmids of all strains were nopaline type. All strains were sensitive to agrocin 84, which suggested that crown gall disease of cherry could be controlled by K84 strain.
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Meng J, Pillot J, Dai X, Fields HA, Khudyakov YE. Neutralization of different geographic strains of the hepatitis E virus with anti-hepatitis E virus-positive serum samples obtained from different sources. Virology 1998; 249:316-24. [PMID: 9791023 DOI: 10.1006/viro.1998.9346] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A recently developed polymerase chain reaction (PCR)-based cell culture neutralization assay was used to investigate cross-neutralization of known hepatitis E virus (HEV) strains obtained from various HEV-endemic regions of the world with different anti-HEV-positive serum samples. Serum specimens obtained from cynomolgus macaques experimentally infected with strains from Burma, Mexico, or Pakistan cross-neutralized the infectivity of each strain as well as an isolate from Morocco. Serum samples obtained either from infected patients who reside in HEV-endemic regions of the world or from U.S. residents who became infected while traveling to such regions also neutralized all four strains. In contrast, antibodies obtained from rabbits immunized with full-length Burma strain ORF2 protein neutralized only the Burma and Pakistan strains, not the Mexico or Morocco strains. In addition, antibodies obtained from guinea pigs immunized with an N-terminal truncated Burma strain ORF2 protein neutralized each strain except the Morocco strain. These data strongly suggest that antibodies elicited during an HEV infection demonstrate broad HEV neutralizing activity, whereas antibodies elicited after immunization with recombinant Burma ORF2 protein demonstrate a more limited ability to neutralize various HEV strains obtained from different regions of the world endemic for the disease.
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264
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Dai X, Rothman-Denes LB. Sequence and DNA structural determinants of N4 virion RNA polymerase-promoter recognition. Genes Dev 1998; 12:2782-90. [PMID: 9732275 PMCID: PMC317147 DOI: 10.1101/gad.12.17.2782] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/1989] [Accepted: 07/07/1998] [Indexed: 11/24/2022]
Abstract
Coliphage N4-coded, virion-encapsidated RNA polymerase (vRNAP) is able to bind to and transcribe promoter-containing double-stranded DNAs when the template is supercoiled and Escherichia coli single-stranded DNA-binding protein (Eco SSB) is present. We report that vRNAP-promoter recognition and activity on these templates require specific sequences and a hairpin structure on the template strand. Hairpin extrusion, induced by Mg(II) and physiological superhelical density, is essential to provide the correct DNA structure for polymerase recognition, as mutant promoters that do not form hairpins show reduced in vitro activity. Therefore, a supercoil-induced DNA structural transition regulates N4 vRNAP transcription. Eco SSB activates transcription at physiological superhelical densities by stabilizing the template-strand hairpin. Specific sequences at the promoters are conserved to provide proper contacts for vRNAP, to support hairpin extrusion, or both. We propose a model for in vivo utilization of the vRNAP promoters, and discuss the roles of DNA supercoiling and Eco SSB in promoter activation.
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265
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Zhou B, Dai X, He A. [Molecular marker as an indicator in presaging prognosis of human lung adenocarcinoma]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 1998; 19:231-3. [PMID: 10322679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
The paper discusses 93 cases of human lung adenocarcinoma in terms of molecular-epidemiology. The relationship between p21 protein and p53 protein and proliferating cell nuclear antigen (PCNA) was analysed by immunohischemical methods. Prognosis by Cox model was used for prosnosis prediction of adenocarcinoma in human lung. Results showed that the prognosis of adenocarcinoma was poor when of p21 protein expression was positive and the relative ratio was 2.08. However, p53 protein expression was not related to the prognosis of adenocarcinoma. The higher the positive rate of PCNA was, the poorer the prognosis of adenocarcinoma oppeared, with a ratio of 3.27.
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266
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Zeng J, Dai X, Yang J. [159 sterility patients of yang-deficiency of spleen and kidney treated by shouwu huanjing capsule]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 1998; 18:477-9. [PMID: 11477832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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267
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Jiang X, Cubitt WD, Berke T, Zhong W, Dai X, Nakata S, Pickering LK, Matson DO. Sapporo-like human caliciviruses are genetically and antigenically diverse. Arch Virol 1998; 142:1813-27. [PMID: 9672639 DOI: 10.1007/s007050050199] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Sapporo-like human caliciviruses (HuCVs) comprise one of three genogroups of HuCVs associated with acute gastroenteritis. Phylogenetic analysis has shown that Sapporo-like HuCVs are related more closely to animal caliciviruses than to other known HuCVs. We produced 3.2 kb cDNA fragments from the 3' end to three Sapporo-like HuCVs that were associated with acute gastroenteritis in children (Houston/86, Houston/90, and London/92). Sequence analysis of the 3.2 kb cDNAs showed that two of the three viruses had a genomic organization similar to that of other Sapporo-like strains and the third strain (London/92) lacked an open reading frame overlapping the 5' end of the capsid gene. Alignment of the capsid sequences of these three strains showed 44-78% amino acid identity among the three strains. Phylogenetic analysis of the aligned sequences indicated the three strains are related but each belongs to a distinct genetic cluster. The genetic differences are associated with antigenic differences in that an enzyme immune assay (EIA) specific for the prototype Sapporo/82 strain detected the Houston/86 strain, but not the Houston/90 and London/92 strains. In vitro transcription and translation of viral cDNA containing the predicted capsid gene of Houston/90 resulted in a protein of 63 K, which is immunoprecipitated by sera from children infected with the strain. Genetically and antigenically distinct strains in the Sapporo-like HuCVs have not been described previously and the occurrence of such diverse strains in the same community likely increases the importance of these strains as a cause of illness in children.
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Li K, Yuan Y, Dai X, Qao X. [Determination of triptolide in extract from leigongteng (Tripterygium Wilfordii Hook. F.) by RP-HPLC]. Se Pu 1998; 16:356-7. [PMID: 11367766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023] Open
Abstract
A reversed-phase liquid chromatographic method has been developed and validated for the analysis of triptolide in extract from Leigongteng (Tripterygium Wilfordii Hook. F.). The drugs were eluted with petroleum-ethyl acetate on a neutral alumina cartridge and then measured by HPLC using a Hypersil C18 column and acetonitrile-water (40:60, V/V) mobile phase. Triptolide was quantified by ultraviolet absorbance at 210 nm. The method proved to be linear in the range of 0.25-4.00 mg/L with a regression coefficient of 0.9997. The lower limit of detection of triptolide was 0.1 mg/L. Intra-day and inter-day coefficients of variation of assay for triptolide were 1.9%-6.5% (n = 5) and 2.7%-7.8% (n = 5), respectively. The recoveries of the method were 89.8%-92.0%.
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269
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Yin D, Dai X, Rao X. [Yishen huanshuai recipe retard progression of chronic renal failure]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 1998; 18:402-4. [PMID: 11477814] [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 investigate the effect of Yishen Huanshuai recipe (YSHSR) on the progression of chronic renal failure (CRF). METHODS Forty-six patients with CRF were divided into two groups: group A (self-controlled group, n = 18), whose treatment was subdivided into two stages. During the first stage, the patients treated with low protein diet and controlling blood pressure, while in the second stage, YSHSR was given. Group B(n = 28), whose treatment plan was similar with that of group A in second stage. The rate of progression of CRF was estimated by slope of the creatinine reciporcal (dl/mg) with time (month). RESULTS Mean slope of the creatinine reciprocal with time from the group A during the first stage was -0.0104 +/- 0.0021, while during the second stage, it was -0.0034 +/- 0.0018. There was significant difference between them (P < 0.05). Mean slope from the group B was -0.0047 +/- 0.0020. There was also significant difference between that from the group B and that from the group A during the first stage (P < 0.05). CONCLUSIONS Low protein and controlling blood pressure plus YSHSR therapy could markedly retard the rate of progression of CRF.
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270
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Yang L, Yuan Y, Dai X. [Determination of felodipine concentration in human plasma by GC-ECD and study of its pharmacokinetics]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 1998; 33:461-4. [PMID: 12016918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
A rapid, accurate and sensitive gas chromatographic method using electron-capture detector (GC-ECD) was developed for the determination of felodipine concentration in human plasma. Nimodipine was used as internal standard. The plasma samples were extracted using a mixture of ethyl ether and n-hexane (2:1) to give mean recoveries of 97.3% of felodipine. The extracts were separated by a 5% SE-30 glass packed column (2 m x 3 mm). The detection limits for felodipine was 0.25 ng.ml-1. The precisions (RSD%, n = 5) of within-day and day-to-day were less than 5.09% and 8.62%, respectively. The pharmacokinetic parameters of felodipine in ten men were investigated by this method. The concentration-time curve was fitted to a two-compartment model. Its main pharmacokinetic parameters were: T1/2 alpha = 0.76 h, T1/2 beta = 16.09 h, Cmax = 4.78 ng.ml-1, Tmax = 2.01 h, AUC = 45.2 h.ng.ml-1.
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271
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Jiang X, Dai X, Goldblatt S, Buescher C, Cusack TM, Matson DO, Pickering LK. Pathogen transmission in child care settings studied by using a cauliflower virus DNA as a surrogate marker. J Infect Dis 1998; 177:881-8. [PMID: 9534959 DOI: 10.1086/515253] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Two regions of cauliflower mosaic virus DNA were designed as markers to study pathogen transmission in a child care home (CCH) and child care center (CCC) and in homes of CCC children. The DNA markers were stable for 1 month in the environment. The DNA markers were introduced into the environment through sensitized objects, and spread in the environment was traced by detection of the markers with polymerase chain reaction. The DNA markers spread rapidly in both the CCH and CCC after introduction and spread more rapidly in the toddler room than in the infant room of the CCC. Hand touching of contaminated areas was the major factor leading to spread of the markers. Hand washing and surface wiping decreased spread of the markers. The markers spread minimally from room to room in the CCC but were detected in the children's homes after introduction of markers in the CCC.
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272
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Dai X, Snyder WE, Bilbro GL, Williams R, Cowan R. Left-ventricle boundary detection from nuclear medicine images. J Digit Imaging 1998; 11:10-20. [PMID: 9502322 PMCID: PMC3453152 DOI: 10.1007/bf03168721] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We present here a new algorithm for segmentation of nuclear medicine images to detect the left-ventricle (LV) boundary. In this article, other image segmentation techniques, such as edge detection and region growing, are also compared and evaluated. In the edge detection approach, we explored the relationship between the LV boundary characteristics in nuclear medicine images and their radial orientations: we observed that no single brightness function (eg, maximum of first or second derivative) is sufficient to identify the boundary in every direction. In the region growing approach, several criteria, including intensity change, gradient magnitude change, gradient direction change, and running mean differences, were tested. We found that none of these criteria alone was sufficient to successfully detect the LV boundary. Then we proposed a simple but successful region growing method--Contour-Modified Region Growing (CMRG). CMRG is an easy-to-use, robust, and rapid image segmentation procedure. Based on our experiments, this method seems to perform quite well in comparison to other automated methods that we have tested because of its ability to handle the problems of both low signal-to-noise ratios (SNR) as well as low image contrast without any assumptions about the shape of the left ventricle.
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273
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Dai X. [Yeast Pichia pastoris--a notable heterologous gene expression system]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 1997; 37:483-5. [PMID: 11189384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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274
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Johnson RB, Gilbert JA, Cooper RC, Dai X, Newton BI, Tracy RR, West WF, DeMoss TL, Myers PJ, Streckfus CF. Alveolar bone loss one year following ovariectomy in sheep. J Periodontol 1997; 68:864-71. [PMID: 9379331 DOI: 10.1902/jop.1997.68.9.864] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
There is little information concerning the incidence of alveolar bone loss in estrogen-deficient women. Ovariectomized sheep are valid models for study of the effects of estrogen deficiency on bone metabolism. The objective of this study was to compare alveolar bone loss in control (C) and ovariectomized sheep (OVX) at 3 and 12 months following surgery. OVX animals had decreased serum levels of 17-beta-estradiol and increased serum levels of osteocalcin, IL-6, and urinary levels of deoxypyridinoline which, taken together, suggest development of osteoporosis. The mean probing depths and percentage of sites with pocket depths 4 to 6 mm and > 6 mm were significantly greater in OVX than C at each time period and in OVX were significantly greater at 12 months that at 3 months. Gingival tissue interleukin-6 (IL-6) levels (but not the number of IL-6(+) cells) were elevated adjacent to deep periodontal pockets; however, there was no significant elevation of levels of the proinflammatory cytokines IL-1 beta and IL-8 within gingiva. Taken together, the data suggest a systemic contribution for progression of periodontal disease associated with estrogen deficiency. This may involve upregulation of systemic IL-6 synthesis and transfer to gingiva in serum, resulting in enhanced IL-6 accumulation within the gingival tissues or reduced bone density allowing for a greater amount of alveolar bone loss.
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Dai X, Sasaki O, Greivenkamp JE, Suzuki T. High accuracy, wide range, rotation angle measurement by the use of two parallel interference patterns. APPLIED OPTICS 1997; 36:6190-6195. [PMID: 18259466 DOI: 10.1364/ao.36.006190] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Based on the idea of measuring small rotation angles with a parallel interference pattern (PIP), a method is developed to measure large rotation angles accurately. Two parallel PIP's that have different periods are used to measure a rotation angle of an object. The measurement made with a small-period PIP provides a high accuracy, and the measurement made with a large-period PIP provides a wide range. An accurate measurement for wide-range angles is made by combining the two measured values. The accuracy of the phase detection is determined by the periods of two PIP's. Rotation angles from approximately -30 to 30 arc min can be measured with an accuracy of 0.2 arc sec. Analytical results are supported by experimental results.
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276
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Yan Z, Zhu D, Dai X, Wang Y. [Introduction and analysis of the information on projects received and supported in division of microbiology NSFC in 1996]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 1997; 37:237-44. [PMID: 9863217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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277
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Dai X, Greizerstein MB, Nadas-Chinni K, Rothman-Denes LB. Supercoil-induced extrusion of a regulatory DNA hairpin. Proc Natl Acad Sci U S A 1997; 94:2174-9. [PMID: 9122167 PMCID: PMC20060 DOI: 10.1073/pnas.94.6.2174] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Bacteriophage N4 virion RNA polymerase (N4 vRNAP) promoters contain inverted repeats, which form a 5- to 7-base-pair stem, 3-base loop hairpin that is required for vRNAP recognition. We show that, contrary to certain theoretical predictions, hairpin extrusion can occur at physiological superhelical densities in a Mg2+-dependent manner. Specific sequences on the template strand are required for hairpin extrusion. These sequences define stable DNA hairpins that are relatively unreactive to single strand-specific probes. In addition, a specific stable hairpin-inducing sequence can regulate transcription in vivo. Thus, a DNA structure, in its natural environment, is involved in transcriptional regulation.
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278
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Zhang L, Zhao G, Dai X, Duan J, Dou Y. Manifestation of Behcet's disease in the digestive tract. Chin Med J (Engl) 1997; 110:195-7. [PMID: 9594339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE To study the manifestations of Behcet's disease (BD) in the digestive tract and its differential diagnosis from common inflammatory bowel diseases. METHODS The symptoms and endoscopic, X-ray's or surgical characteristics of 24 cases of Behcet's disease with digestive tract manifestations were analysed. RESULTS The lesions mainly occurred in tileocecum, and frequently led to hemorrhage that required surgery. The recurrent rate was as high as 77.7%. CONCLUSION Importance should be attached to early diagnosis of BD of the digestive tract to prevent serious complications.
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279
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Ji X, Li S, Kong X, Xu G, Chen J, Dai X. Clinical significance of serum 7S collagen and type VI collagen levels for the diagnosis of hepatic fibrosis. Chin Med J (Engl) 1997; 110:198-201. [PMID: 9594340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE To measure serum 7S collagen (7S-C) and type VI collagen (VI-C) levels by radioimmunoassay (RIA) in Chinese patients with various liver disorders and in CCl4-treated SD rats, and to investigate the significance of the elevated levels of serum 7S-C and VI-C. METHODS Serum 7S-C and VI-C levels were measured in 40 healthy control subjects, 168 patients with various liver disorders and non-hepatic diseases, and 52 CCl4-treated SD rats by using RIA which was developed in our hospital. RESULTS Serum 7S-C and VI-C were significantly elevated in patients with chronic active hepatitis (CAH), liver cirrhosis (LC), hepatic cellular carcinoma (HCC) (P < 0.01 respectively), chronic persistent hepatitis (CPH), and some with non-hepatic diseases (P < 0.05). Serum 7S-C, serum laminin and hyaluronic acid were well correlated. Serum 7S-C and VI-C were not closely correlated. Both collagens were correlated with serum albumin/globulin ratio, aminotransferase and total bilirubin, not with alkaline phosphatase. In CCl4-treated SD rats, serum 7S collagen and type VI collagen levels were correlated with the degree of hepatic fibrosis. CONCLUSIONS Serum 7S collagen and type VI collagen are useful markers for diagnosing liver fibrosis. And the combined measurement of IV-C, VI-C and other markers of connective tissue metabolism or biochemical data seems to provide additional information to predict progressive hepatic fibrosis.
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280
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Liang Z, Ma D, Tang L, Hong Y, Luo A, Zhou J, Dai X. Expression of the spinach betaine aldehyde dehydrogenase (BADH) gene in transgenic tobacco plants. CHINESE JOURNAL OF BIOTECHNOLOGY 1997; 13:153-9. [PMID: 9429776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Plasmid pLS9 contains a 1.5-kb of spinach cDNA including its complete open reading frame. The 1.5-kb BADH cDNA was cut from pLS9 using restriction enzyme and was inserted into the expression cassette of plasmid pYH between the CaMV 35S promoter and polyA signal sequence. The 35S-BADH cDNA-polyA fragment of pYH was cloned into a polylinker cloning site of the binary vector pBin19. The resulting plasmid pBinBADH-S was transferred to Agrobacterium tumefacies LBA4404. The tobacco plants were transformed with strain LBA4404 containing pBinBADH-S, and more than ninety kanamycin-resistant transformants were selected. Polymerase chain reaction (PCR) detection showed that more than 60% of the transformed tobacco plants contained the foreign BADH gene. The Western blot analysis, BADH enzymatic assay, specific stain for BADH activity, and the test for salt tolerance showed that BADH gene was normally expressed in the transgenic tobacco plants. The BADH enzymes also presented in chloroplasts and cytosol of the transgenic plants. The transgenic tobacco plants having strong expression of BADH gene had strong ability to tolerate high salt stress.
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281
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Li J, Zhao F, Tian D, Dai X, Zhang X, Shi X, Lu X, Fang J. [Effect of xiaopiling granules on the treatment of gastric precancerous changes as detected by image analyzer and electronic microscope]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1996; 21:691-3 inside back cover. [PMID: 9812703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Therapeutic effect of Xiaopiling Granules on gastric precancerous changes was observed, using image analyzer and electronic microscope. The result indicated that the Granules could efficiently eliminate gastric mucositis, nourish gastric mucosa, soften or restrain dysplasia, ameliorate structure atypism and cell atypism of dysplasia, promote elimination of dysplasia and efficiently ameliorate the ultrastructure of gastric precancerous changes.
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282
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Dai X, Sasaki O, Greivenkamp JE, Suzuki T. Measurement of two-dimensional small rotation angles by using orthogonal parallel interference patterns. APPLIED OPTICS 1996; 35:5657-5666. [PMID: 21127572 DOI: 10.1364/ao.35.005657] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Based on measuring one-dimensional small rotation angles by using a parallel interference pattern (PIP), a method for measuring two-dimensional (2D) small rotation angles by using two different PIP's that are orthogonal to each other is proposed. We simultaneously measure the 2D small rotation angles Δθ and Δφ by detecting the phases of the orthogonal PIP's reflected by an object at two detection points. A sensitivity of 4.9 mrad/arcsec and a spatial resolution of 1.5 × 1.5 mm(2) are achieved in the measurement. Theoretical analysis and experimental results show that error ε(1) in the measurement of Δφ is almost equal to -0.01Δθ and error ε(2) in the measurement of Δθ is almost equal to -0.01Δφ. For small rotation angles of less than a few tens of arcseconds, the random errors whose standard deviations are 0.6 arcsec are dominant.
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283
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Lombardo A, Wang Y, Ni CZ, Dai X, Dickinson CD, Kodandapani R, Chiang S, White CA, Pio F, Xuong NH, Hamlin RC, Ruoslahti E, Ely KR. Conformational flexibility and crystallization of tandemly linked type III modules of human fibronectin. Protein Sci 1996; 5:1934-8. [PMID: 8880920 PMCID: PMC2143538 DOI: 10.1002/pro.5560050922] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Fibronectin is a large cell adhesion molecule that is composed of several functional domains. The cell-binding domain that binds to cell surface integrins consists of repeated homologous type III modules. In this study, recombinant fragments from the cell-binding domain of human fibronectin that participate in a newly characterized fibronectin-fibronectin interaction with FNIII1 were crystallized. In each case, the crystals had more than one fibronectin fragment in the asymmetric unit. Crystals of FNIII10-11 grew in the space group C2 with a = 117.1 A, b = 38.6 A, c = 80.6 A, beta = 97.2 degrees, and two molecules in the asymmetric unit. These crystals diffracted to 2.5 A resolution. Fragment FNIII8-11 and a shorter fragment, FNIII8-10, crystallized in hexagonal space groups with large unit cells and two to four molecules per asymmetric unit. Even very large crystals of these fragments did not diffract beyond 4 A. The crystal packing for this collection of fibronectin fragments suggests conformational flexibility between linked type III modules. The functional relevance of this flexibility for elongated versus compact models of the cell-binding domain of fibronectin is discussed.
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284
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285
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Joyce GF, Dai X, De Mesmaeker A. Amide Cleavage by a Ribozyme: Correction. Science 1996. [DOI: 10.1126/science.272.5258.15f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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286
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Joyce GF, Dai X, De Mesmaeker A. Amide cleavage by a ribozyme: correction. Science 1996; 272:18-9. [PMID: 8600526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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287
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Jiang Y, Xia S, Dai X. [Expression of CDKN2 gene product in human bronchogenic carcinoma]. ZHONGHUA JIE HE HE HU XI ZA ZHI = ZHONGHUA JIEHE HE HUXI ZAZHI = CHINESE JOURNAL OF TUBERCULOSIS AND RESPIRATORY DISEASES 1996; 19:81-3. [PMID: 9388844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To examine the expression of P16 protein in bronchogenic carcinoma and normal tissue adjacent to carcinoma and to determine the relationship between the gene and bronchogenic carcinoma. METHOD Using a rabbit polyclonal antibody against P16 (N-20), the expression of P16 protein was studied immunohistochemically on formalin fixed, paraffin embedded sections. RESULTS The cytoplasmic P16 protein was mainly present in normal bronchial epithelium (93.8%), serous gland (92.6%) and alveolar epithelium (71.4%), the expression levels of P16 were significantly lower in carcinoma tissues (61.9%) when compared to levels in their normal counterparts (P < 0.01). Among tumors, squamous cell carcinomas and small cell carcinomas exhibited lower P16 expression levels compared with adenocarcinomas (P < 0.01). The expression levels of P16 were lower in poorly-differentiated adenocarcinomas compared with those in well-differentiated adenocarcinomas (P < 0.05). CONCLUSIONS The results suggested that CDKN2 gene was a tumor suppressor gene, the inactivation of which were involved in the carcinogenesis of bronchogenic carcinoma and implicated in tumor differentiation.
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288
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Zhang J, Chen Y, Dai X, Wang S. Analysis of the N-glycosylation of the serum glycoproteins defined by Con A, PHA-E, RCA1 and WGA in Chinese patients with gastrointestinal diseases. CHINESE MEDICAL SCIENCES JOURNAL = CHUNG-KUO I HSUEH K'O HSUEH TSA CHIH 1996; 11:36-40. [PMID: 9206117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Glycoproteins from tumor cells isolated by Con A, PHA-E and RCA1, were coupled to horse radish peroxidase and then used as reporters to evaluate the oligosaccharides change on serum glycoproteins in digestive tract diseases and individual healthy persons. A value 2 standard deviation above the mean of the healthy person group was considered positive. The results indicated that the positive rates of the oligosaccharides bound with Con A, PHA-E and RCA1 were 51% (61/119), 70.6% (84/119), and 76.4% (91/119) in patients with gastric cancer; 53.3% (16/30), 46.7% (14/30) and 66.7% (20/30) in esophageal cancers; 28.5% (15/49), 49.0% (24/49) and 46.9% (23/49) in colorectal cancer; 78.1% (25/32), 81.3% (26/32) and 31.3% (10/32) in gallbladder tumors; 60.4% (29/48), 54.1% (26/48) and 39.5% (19/48) in hepatocellular cancer. The positive rates among the patients with benign diseases were also found to be 12.7% (16/126), 15.5% (20/126) and 26.2% (33/126). However, the expression of the oligosaccharide moieties recognized by WGA on the glycoprotein bound with Con A, was significantly lower in the serum of patients with tumors than in those with benign disease and in healthy individuals (P < 0.01, P < 0.01).
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289
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Glucksmann-Kuis MA, Dai X, Markiewicz P, Rothman-Denes LB. E. coli SSB activates N4 virion RNA polymerase promoters by stabilizing a DNA hairpin required for promoter recognition. Cell 1996; 84:147-54. [PMID: 8548819 DOI: 10.1016/s0092-8674(00)81001-6] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Bacteriophage N4 virion RNA polymerase transcription of double-stranded promoter-containing DNAs requires supercoiled template and E. coli single-stranded DNA-binding protein (EcoSSB); other single-stranded DNA-binding proteins cannot substitute. The DNA determinants of virion RNA polymerase binding at the promoter comprise a small template-strand hairpin. The requirement for EcoSSB is surprising, since single-stranded DNA-binding proteins destabilize hairpin structures. DNA footprinting of EcoSSB on wild-type and mutant promoters indicates that EcoSSB stabilizes the template-strand hairpin owing to the hairpin-loop sequences. Other single-stranded DNA-binding proteins destabilize the promoter hairpin, explaining the specificity of EcoSSB activation. We conclude that EcoSSB activates transcription by providing the appropriate DNA structure for polymerase binding. The existence of small hairpins stable to single-stranded protein binding suggests a novel mechanism that provides structural determinants for specific recognition in single-stranded DNA transactions by an otherwise nonspecific DNA-binding protein.
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290
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Miller A, Dai X, Choi M, Glucksmann-Kuis MA, Rothman-Denes LB. Single-stranded DNA-binding proteins as transcriptional activators. Methods Enzymol 1996; 274:9-20. [PMID: 8902792 DOI: 10.1016/s0076-6879(96)74004-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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291
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Lin C, Dai X, Sun X. [Expression of oncogene and anti-oncogene in mouse lung cancer induced by coal-burning smoke]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1995; 17:432-4. [PMID: 8697995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Previous epidemiology studies have shown association between coal burning and human lung cancer. To confirm relationship of coal burning to lung cancer formation and progression the expression of p53 and c-myc in 13 mouse lung cancer induced by coal-burning smoke and 5 mouse lung tissue control was studied by DNA-RNA in situ hybridization (ISH). Nine of 13 specimens showed c-myc overexpression but it occurred only 1 in 9 in the adjacent tissue. There was overexpression of p53 mRNA in all 13 lung cancer and 5 adjacent tissues. None in the controls was expression of p53 and c-myc detected. When compared to controls, there was significant higher expression of c-myc gene (P = 0.002) and p53 gene (P = 0.0001). The results confirm that overexpression of p53 and c-myc are common molecular events of lung cancer by coal-burning smoke and provide further evidence that smoke from coal burning is a causative agent of lung cancer.
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292
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Suarez SS, Dai X. Intracellular calcium reaches different levels of elevation in hyperactivated and acrosome-reacted hamster sperm. Mol Reprod Dev 1995; 42:325-33. [PMID: 8579847 DOI: 10.1002/mrd.1080420310] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Calcium plays a role in sperm motility hyperactivation and the acrosome reaction, but the relationship between cytoplasmic calcium (Ca2+in) levels in the two states was heretofore unknown. The Ca2+ indicator indo-1 was used to detect Ca2+in in moving hamster sperm in two sets of experiments. In the first experiment, activated, hyperactivated, and zona pellucida-induced acrosome-reacted/hyperactivated sperm were analyzed at the time of peak of activity for each state. In the second experiment, sperm in all states were analyzed at one time point. In both sets, mean Ca2+in in the acrosomal region, postacrosomal region, and flagellar midpiece was greater in hyperactivated sperm than in activated sperm, and in acrosome-reacted/hyperactivated sperm than in unreacted/hyperactivated sperm (P < 0.001). Ca2+in had increased to a greater extent in the midpiece than in the head in hyperactivated sperm, while the reverse was true for acrosome-reacted sperm. Oscillations at the frequency of the flagellar beat cycle were detected chiefly in the proximal flagellar midpiece of acrosome-reacted sperm, as they had been previously reported to occur in activated and hyperactivated sperm. Thus, Ca2+in may be maintained at two different elevated levels in sperm, and continues to oscillate after the acrosome reaction.
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293
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Jiang X, Cubitt D, Hu J, Dai X, Treanor J, Matson DO, Pickering LK. Development of an ELISA to detect MX virus, a human calicivirus in the snow Mountain agent genogroup. J Gen Virol 1995; 76 ( Pt 11):2739-47. [PMID: 7595381 DOI: 10.1099/0022-1317-76-11-2739] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
MX virus is a Snow Mountain agent (SMA) genogroup human calicivirus (HuCV) identified in a Mexican child with diarrhoea. An ELISA using hyperimmune antisera to the recombinant MX virus (rMX) capsid was developed to detect SMA genogroup HuCVs in stool specimens. The rMX ELISA detected the prototype MX virus, SMA, and Hawaii agent (HA), but not Norwalk virus (NV) or Sapporo virus. Twenty-three diarrhoea stool specimens from children attending day care centres in Norfolk, Virginia, were positive by the rMX ELISA and results were confirmed by reverse transcription-polymerase chain reaction (RT-PCR). Eight of 20 diarrhoea stool specimens from children in the United Kingdom previously shown to contain small round structured viruses (SRSVs) or HuCVs by electron microscopy were also positive by the rMX ELISA and RT-PCR. Sequence analysis of the RT-PCR products showed that all the rMX ELISA-positive viruses belong to the SMA genogroup. These data also showed that the SMA genogroup can be further divided into two subgroups: subgroup 1 includes prototypes SMA and HA, and subgroup 2 includes MX virus, minireovirus, Oth-25 and Bristol virus.
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294
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Li X, Dai X, He A. [T antigen test of sputum--a new simple method for the screening of lung cancer]. ZHONGHUA JIE HE HE HU XI ZA ZHI = ZHONGHUA JIEHE HE HUXI ZAZHI = CHINESE JOURNAL OF TUBERCULOSIS AND RESPIRATORY DISEASES 1995; 18:285-6, 317. [PMID: 8762480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The sputum specimens from 116 healthy persons and 216 cases of benign and malignant lung diseases were detected for T antigen using a strip test by enzyme galactose oxidase-Schiff sequence. The result shows that 165 cases of the 182 patients with lung cancer, confirmed by cytology and histology, had positive results, whereas 22/116 (19.0%) of healthy controls were positive. So the sensitivity was 90.7% and the specificity was 81.0%. In 28 cases of patients whose cytology of sputa showed various degrees of dysplasia, 21 were found T antigen positive, of which 15 patients were identified to be lung cancer in the follow-up study. In addition, three cases of early lung cancer in this study were also positive, suggesting that T antigen was expressed at an earlier stage in the malignant process. The study has indicated that T antigen test of sputum is a sensitive method for the diagnosis of lung cancer. It may also be a promising approach for the massive screening of lung cancer in terms of its rapidity, economy and simplicity.
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295
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Dai X, Sasaki O, Greivenkamp JE, Suzuki T. Measurement of small rotation angles by using a parallel interference pattern. APPLIED OPTICS 1995; 34:6380-6388. [PMID: 21060484 DOI: 10.1364/ao.34.006380] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We propose a method for measuring rotation angles by using a parallel interference pattern. At two points on a parallel interference pattern reflected by an object, we detect phase changes in the reflected parallel interference pattern caused by rotations of the object. A high sensitivity, or a high ratio of the phase change to the rotation angle, 17 mrad/arcsec, can be achieved by determining the positions of two detection points. A high spatial resolution of ~0.5 mm is also obtained. We analyze the measurement error caused by the alignment of the parallel interference pattern and a random measurement error caused by the phase detection. The theoretical analyses and the experimental results make the characteristics of the method clear and show that the method has an accuracy of 0.2 arcsec for small rotation angles.
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296
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Zhao F, Lu X, Dai X, Pu Y, Zhang X, Shi X, Fang J, Dong J, Tian D, Ma Q. [Effects of three kinds of decoction on histopathology of gastric mucosa, gastric pH and the content of bile acid in experimental chronic gastritis in rats]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1995; 20:488-92, inside backcover. [PMID: 8561888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Experimental chronic gastritis (ECG) models were established in rats by inserting a spring into pyloric canal as well as feeding sodium deoxycholate. An experiment was undertaken to observe the therapeutic effects of three formulas of traditional Chinese medicine "Shipitong", "Ganpingyangwei" and "Weile". The experimental results show that all of the three decoctions can reduce gastric pH and bile acid of the ECG rats and make gastric mucosal histomorphology of these rats change markedly.
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297
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Lu X, Zhao F, Dai X, Zhang X, Pu Y, Fang J, Shi X, Liu X, Zhou G, Ren Y. [Effects of 3 kinds of decoction on serum gastrin, gastrin cell density and the content of PGE2 of gastric antral mucosa in experimental chronic gastritis in rats]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1995; 20:361-4, 384. [PMID: 7646809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Experimental chronic gastritis (ECG) models were established in rats by inserting a spring into pyloric canal as well as feeding sodium deoxycholate. An experiment was undertaken to observe the therapeutic effects of three formulas of traditional Chinese medicine "Shipitong" (SPT), "Ganpingyangwei" (GPYW) and "Weile" (WL). The experimental results show that all of the three decoctions can make serum gastrin, gastrin cell density and amount of antral mucosal PGE2 of the ECG rats return to normal levels.
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298
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Noga BR, Fortier PA, Kriellaars DJ, Dai X, Detillieux GR, Jordan LM. Field potential mapping of neurons in the lumbar spinal cord activated following stimulation of the mesencephalic locomotor region. J Neurosci 1995; 15:2203-17. [PMID: 7891162 PMCID: PMC6578129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The spinal neurons involved in the control of locomotion in mammals have not been identified, and a major step that is necessary for this purpose is to determine where these cells are likely to be located. The principal objective of this study was to localize lumbar spinal interneurons activated by stimulation of the mesencephalic locomotor region (MLR) of the cat. For this purpose, extracellular recordings of MLR-evoked cord dorsum and intraspinal field potentials were obtained from the lumbosacral enlargement during fictive locomotion in the precollicular-postmammillary decerebrate cat preparation. Potentials recorded from the dorsal surface of the cord between the third lumbar (L3) and first sacral (S1) segments typically showed four short-latency positive waves (P1-P4). These P-waves were largest between the L4-L6 segments. The amplitude of the P2-4 waves increased with the appearance of locomotion and displayed rhythmic modulation during the locomotor step cycle. Microelectrode recordings from the L4-L7 spinal segments during fictive locomotion revealed the presence of both positive and negative short-latency MLR-evoked intraspinal field potentials, and were used to construct isopotential maps of the evoked potentials. Positive field potentials were observed throughout the dorsal horn of the L4-L7 spinal segments with the largest amplitude potentials occurring in laminae III-VI. Negative field potentials were found in laminae VI-X of the lumbar cord. The shortest latency negative field potentials were observed in lamina VII and at the border between laminae VI and VII and were considered to be evoked monosynaptically from the arrival of the descending volley. Short-latency mono- and disynaptic negative field potentials were also observed in lamina VIII. Longer latency, tri- and polysynaptic field potentials were observed in laminae VII and VIII. Many of the longer latency negative waves observed in laminae VII and VIII followed shorter latency negative potentials recorded from the same location. Laminae VII and VIII negative field potentials were largest in the L5-6 and L4-5 spinal segments, respectively. Negative field potentials were also evoked in the motor nuclei of the L4-7 spinal segments. The segmental latencies for these potentials indicate that they were evoked di- and trisynaptically.(ABSTRACT TRUNCATED AT 400 WORDS)
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299
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Xu Z, Dai X, Viehland D. Impurity-induced incommensuration in antiferroelectric La-modified lead zirconate titanate. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:6261-6271. [PMID: 9977164 DOI: 10.1103/physrevb.51.6261] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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300
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Dai X, Li JF, Viehland D. Weak ferroelectricity in antiferroelectric lead zirconate. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:2651-2655. [PMID: 9979034 DOI: 10.1103/physrevb.51.2651] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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