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Han C, Qiao G, Hubbert NL, Li L, Sun C, Wang Y, Yan M, Xu D, Li Y, Lowy DR, Schiller JT. Serologic association between human papillomavirus type 16 infection and esophageal cancer in Shaanxi Province, China. J Natl Cancer Inst 1996; 88:1467-71. [PMID: 8841021 DOI: 10.1093/jnci/88.20.1467] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND The existence of large geographic variations in the prevalence of esophageal cancer in some countries, such as China, indicates that environmental risk factors may be important in the development of this disease. Some studies have implicated genital-mucosal strains of human papillomaviruses (HPVs) in the etiology of this cancer. PURPOSE We conducted a case-control study in Shaanxi Province, China, an area with a population at high risk for esophageal cancer, to assess the association of this disease with infection by HPV type 16 (HPV16), the most common cancer-associated genital-mucosal HPV type. METHODS Ninety individuals with esophageal cancer and 121 cancer-free control subjects were identified among the patients in two hospitals in Xi'an, Shaanxi Province. The control subjects were matched to the case patients on the basis of age and sex. Blood specimens were drawn from all study subjects, and serum was isolated by routine methods. The presence of HPV16 antibodies in serum samples was determined by use of an enzyme-linked immunosorbent assay (ELISA) that used baculovirus-derived HPV16 virus-like particles as the antigen. A similar ELISA that used bovine papillomavirus type 1 (BPV1) virus-like particles as the antigen controlled for the specificity of HPV16 seroreactivity. Data from the HPV16 and the BPV1 assays were normalized with respect to results obtained in each assay with a control serum of known HPV16 seroreactivity. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to examine the association between HPV16 seroreactivity and esophageal cancer. Reported P values are two-sided. RESULTS The mean seroreactivity to HPV16 virus-like particles was significantly higher for the cancer patients than for the control subjects (mean value +/- standard deviation = 0.85 +/- 0.22 versus 0.74 +/- 0.18; P<.0001). When the cancer patients and control subjects were compared by sex and age groups, the differences in mean seroreactivity remained statistically significant. The difference in mean seroreactivity to BPV1 virus-like particles between cancer patients and control subjects was not statistically significant (0.81 +/- 0.28 versus 0.88 +/- 0.32; P = .12); this result was not altered when sex and age groups were compared. By use of a cutoff point for HPV16 seropositivity that was established in studies of cervical neoplasia, 24% of the cancer patients were seropositive compared with 7% of the control subjects, yielding a sex- and age-adjusted OR of 4.5 (95% CI = 1.8-11.9). In general, the OR for esophageal cancer increased with increasing HPV16 seroreactivity. CONCLUSIONS AND IMPLICATIONS HPV16 infection may be a risk factor for esophageal cancer. Further studies of the association between HPV16 infection and the incidence of esophageal cancer are needed.
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Wang SZ, Zhou RJ, Yan M. [Nursing of surgical closure of cerebrospinal rhinorrhea from sella turcica by the extranasal ethmoidal approach]. ZHONGHUA HU LI ZA ZHI = CHINESE JOURNAL OF NURSING 1996; 31:329-31. [PMID: 8945151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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353
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Jiang Y, Yan M, Gralla JD. A three-step pathway of transcription initiation leading to promoter clearance at an activation RNA polymerase II promoter. Mol Cell Biol 1996; 16:1614-21. [PMID: 8657136 PMCID: PMC231147 DOI: 10.1128/mcb.16.4.1614] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The progress of transcription bubbles during inhibition in vitro was followed in order to learn how RNA polymerase II begins transcription at the activated adenovirus E4 promoter. The issues addressed include the multiple roles of ATP, the potential effect of polymerase C-terminal domain phosphorylation, and the ability of polymerase to clear the promoter for reinitiation. The results lead to a three-step model for the transition from closed complex to elongation complex, two steps of which use ATP independently. In the first step, studied previously, ATP is hydrolyzed to open the DNA strands over the start site. In a second step, apparently independent of ATP, transcription bubbles move into the initial transcribed region where RNA synthesis can stall. In the third step, transcripts can be made as polymerase is released from these stalled positions with the assistance of an ATP-dependent process, likely phosphorylation of the polymerase C-terminal domain. After this third step, the promoter becomes cleared, allowing for the reinitiation of transcription.
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Kuo WL, Abe M, Rhee J, Eves EM, McCarthy SA, Yan M, Templeton DJ, McMahon M, Rosner MR. Raf, but not MEK or ERK, is sufficient for differentiation of hippocampal neuronal cells. Mol Cell Biol 1996; 16:1458-70. [PMID: 8657119 PMCID: PMC231130 DOI: 10.1128/mcb.16.4.1458] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
To elucidate signal transduction pathways leading to neuronal differentiation, we have investigated a conditionally immortalized cell line from rat hippocampal neurons (H19-7) that express a temperature sensitive simian virus 40 large T antigen. Treatment of H19-7 cells with the differentiating agent basic fibroblast growth factor at 39 degrees C, the nonpermissive temperature for T function, resulted in the activation of c-Raf-1, MEK, and mitogen-activated protein (MAP) kinases (ERK1 and -2). To evaluate the role of Raf-1 in neuronal cell differentiation, we stably transfected H19-7 cells with v-raf or an oncogenic human Raf-1-estrogen receptor fusion gene (deltaRaf-1:ER). deltaRaf-1:ER transfectants in the presence of estradiol for 1 to 2 days expressed a differentiation phenotype only at the nonpermissive temperature. However, extended exposure of the deltaRaf-1:ER transfectants to estradiol or stable expression of the v-raf construct yielded cells that extended processes at the permissive as well as the nonpermissive temperature, suggesting that cells expressing the large T antigen are capable of responding to the Raf differentiation signal. deltaRaf-1:ER, MEK, and MAP kinase activities in the deltaRaf-1:ER cells were elevated constitutively for up to 36 h of estradiol treatment at the permissive temperature. At the nonpermissive temperature, MEK and ERKs were activated to a significantly lesser extent, suggesting that prolonged MAP kinase activation may not be sufficient for differentiation. To test this possibility, H19-7 cells were transfected or microinjected with constitutively activated MEK. The results indicate that prolonged activation of MEK or MAP kinases (ERK1 and -2) is not sufficient for differentiation of H19-7 neuronal cells and raise the possibility that an alternative signaling pathway is required for differentiation of H19-7 cells by Raf.
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Moore JA, Chen A, Yan M, Hurlburt AP, Poulter CD. Identification of the gltX gene encoding glutamyl-tRNA synthetase from Methanobacterium thermoautotrophicum. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1305:113-6. [PMID: 8597593 DOI: 10.1016/0167-4781(95)00234-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The gltX gene encoding glutamyl-tRNA synthetase from Methanobacterium thermoautotrophicum has been cloned, sequenced, and identified. The gene is located immediately downstream of idsA in an operon containing at least three additional ORFs. The deduced protein sequence from gltX contains conserved regions (HIGH and KMSKS) indicative of a class I aminoacyl-tRNA synthetase.
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356
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Liu X, Fang Q, Yan M. [A study on cAMP and Ca-CaM of the epithelium in human normal and cataractous lenses]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 1996; 32:107-9. [PMID: 9206225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE The study was designed to study the relationship between calcium-calmodulin (Ca-CaM) and cyclic adenosine monophosphate (cAMP) systems and their possible cataractogenic effects. METHODS We measured cAMP, Ca and Ca-CaM in the epithelium of human normal and cataractous lenses by enzymic and radioimmunoassay methods. RESULTS The levels of Ca-CaM in the epithelium of senile cataractous lens were higher, while of cAMP were lower than that in the normal lens. CONCLUSION The results imply that the low level of cAMP might cause the high level of calcium in the lens which is possibly a cataractogenic factor. The dangerous role of calcium is amplified by the elevation of Ca-CaM.
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Bokemeyer D, Sorokin A, Yan M, Ahn NG, Templeton DJ, Dunn MJ. Induction of mitogen-activated protein kinase phosphatase 1 by the stress-activated protein kinase signaling pathway but not by extracellular signal-regulated kinase in fibroblasts. J Biol Chem 1996; 271:639-42. [PMID: 8557667 DOI: 10.1074/jbc.271.2.639] [Citation(s) in RCA: 132] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The intracellular mechanisms involved in the activation of extracellular signal-regulated kinase (ERK) are relatively well understood. However, the intracellular signaling pathways which regulate the termination of ERK activity remain to be elucidated. Mitogen-activated protein kinase phosphatase 1 (MKP-1) has been shown to dephosphorylate and inactivate ERK in vitro and in vivo. In the present study, we show in NIH3T3 fibroblasts that activation of the stress-activated protein kinase (SAPK) pathway by either specific extracellular stress stimuli or via induction of MEKK, an upstream kinase of SAPK, results in MKP-1 gene expression. In contrast, selective stimulation of the ERK pathway by 12-O-tetradecanoylphorbol-13-acetate or following expression of constitutively active MEK, the upstream dual specificity kinase of ERK did not induce the transcription of MKP-1. Hence, these findings demonstrate the existence of cross-talk between the ERK and SAPK signaling cascades since activation of SAPK induced the expression of MKP-1 that can inactivate ERK. This mechanism may modulate the cellular response to stimuli which employ the SAPK signal transduction pathway.
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Lin Y, Lee LC, Yan M. Generation of dynamic pressure pulses downstream of the bow shock by variations in the interplanetary magnetic field orientation. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/95ja02985] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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359
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Yan M. An empirical study on the impact of marital residence arrangement upon gender preference in reproduction. CHINESE JOURNAL OF POPULATION SCIENCE 1996; 8:133-41. [PMID: 12291965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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360
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Jiang Y, Yan M, Gralla JD. Abortive initiation and first bond formation at an activated adenovirus E4 promoter. J Biol Chem 1995; 270:27332-8. [PMID: 7592996 DOI: 10.1074/jbc.270.45.27332] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Abortive initiation at the adenovirus E4 promoter was studied by following the production of RNA formed from the initiating nucleotides UpA and CTP. Formation of a specific short RNA via a reaction with appropriate alpha-amanitin sensitivity required promoter, activator, and ATP. In the absence of any of these, an alpha-amanitin-resistant reaction led to lower levels of a product of unknown origin. The alpha-amanitin-sensitive reaction required open promoter complexes, as assayed directly by permanganate probing. This reaction was not blocked by the inhibition of polymerase C-terminal domain kinase activity or by the lack of DNA supercoiling. Thus, formation of the initial bond of the mRNA appears to require activator and ATP to open the DNA but not phosphorylation of the polymerase C-terminal domain. In addition, the abortive initiation reaction was strongly suppressed when all elongation substrates were present, suggesting that cycling to produce high amounts of abortive product is strongly disfavored during productive initiation at this promoter.
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361
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Yan M, Song H, Xie N, Zhang L. [Changes of intestinal flora in senile mouse models and the antagonistic activity of the root of Astragalus membraceus (Fisch) Bge]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1995; 20:624-6, inside backcover. [PMID: 8679084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Inhaled by mice, ozone induced stronger free radical reaction in the organism and led to a series of changes similar to senility. In this way the senility mouse models were established to observe the changes of intestinal flora in senile mice. The senile mice were given the root of Astrogolus membraceus decoction orally. The results showed that the imbalance of intestinal flora in these mice was recovered.
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362
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Yan M, Rothberg LJ, Kwock EW, Miller TM. Interchain Excitations in Conjugated Polymers. PHYSICAL REVIEW LETTERS 1995; 75:1992-1995. [PMID: 10059181 DOI: 10.1103/physrevlett.75.1992] [Citation(s) in RCA: 157] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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363
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Yan M, Chen SP, Mitchell TE, Gay DH, Vyas S, Grimes RW. Atomistic studies of energies and structures of (hk0) surfaces in NiO. ACTA ACUST UNITED AC 1995. [DOI: 10.1080/01418619508239586] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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364
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Yan M. [Care of complications of percutaneous plugging of patent arterial duct]. ZHONGHUA HU LI ZA ZHI = CHINESE JOURNAL OF NURSING 1995; 30:365-6. [PMID: 8631085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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365
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Cui D, Yan M, Wong S, Zhang X, Xu D. [Chemical constituents of stems and leaves of Fritillaria ussuriensis Maxim]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1995; 20:298, 320. [PMID: 7492363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Three compounds were isolated from stems and leaves of Fritillaria ussuriensis. They were identified as adenosine, galacitiol and succinic acid.
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366
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Yan M, Gong X, Zhang Y. [Effects of glucocorticoid on PMN adhesion induced by TNF]. ZHONGHUA ZHENG XING SHAO SHANG WAI KE ZA ZHI = ZHONGHUA ZHENG XING SHAO SHANG WAIKF [I.E. WAIKE] ZAZHI = CHINESE JOURNAL OF PLASTIC SURGERY AND BURNS 1995; 11:99-102. [PMID: 7648511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
TNF was used as a stimulating factor to study the effects of glucocorticoid (GC) on polymorphonuclear leucocyte (PMN) adhesion. The results showed that tumor necrosis factor (TNF) could increase the PMN adhesion markedly, and Dex could not inhibit the PMN adhesion induced by TNF, but it had a certain effect of prevention. PMN adhesion was increased prominently when Dex and RU 38486 were given after TNF pretreatment.
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367
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Hou C, Zhang X, Fang Q, Shou T, Zeng L, Yan M, Zhou Y, Hu B, Li P. The analysis of disparity evoked potentials by a new form of static random-dot stereograms. YAN KE XUE BAO = EYE SCIENCE 1995; 11:48-52. [PMID: 8575607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE A new form of static random-dot stereograms free of monocular clues was designed as stimulus to elicit disparity evoked potentials. METHODS Disparity evoked potentials were recorded in 40 stereo-normal subjects. The stimulator was a white-black static random-dot stereograms generated by a computer and had no monocular clues. Every subject was tested in disparity stimulus, zero disparity stimulus, monocular stimulus and wearing prism condition. RESULTS A characteristic wide positive wave at about 250 ms was consistently recorded in disparity stimulus, which may be regarded as evidence of the presence of stereopsis. In contrast, recordings for zero disparity stimulus, monocular vision, stimulus and wearing prism condition all demonstrated a markedly difference from recording for disparity stimulus.
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368
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Yan M, Dai T, Deak JC, Kyriakis JM, Zon LI, Woodgett JR, Templeton DJ. Activation of stress-activated protein kinase by MEKK1 phosphorylation of its activator SEK1. Nature 1994; 372:798-800. [PMID: 7997270 DOI: 10.1038/372798a0] [Citation(s) in RCA: 602] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A kinase distinct from the MEK activator Raf, termed MEK kinase-1 (MEKK), was originally identified by virtue of its homology to kinases involved in yeast mating signal cascades. Like Raf, MEKK is capable of activating MEK in vitro. High-level expression of MEKK in COS-7 cells or using vaccinia virus vectors also activates MEK and MAPK, indicating that MEKK and Raf provide alternative means of activating the MAPK signalling pathway. We have derived NIH3T3 cell sublines that can be induced to express active MEKK. Here we show that induction of MEKK does not result in the activation of MAPK, but instead stimulates the stress-activated protein kinases (SAPKs) which are identical to a Jun amino-terminal kinase. We find that MEKK regulates a new signalling cascade by phosphorylating an SAPK activator, SEK1 which in turn phosphorylates and activates SAPK.
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369
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Antoniadis H, Rothberg LJ, Papadimitrakopoulos F, Yan M, Galvin ME, Abkowitz MA. Enhanced carrier photogeneration by defects in conjugated polymers and its mechanism. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:14911-14915. [PMID: 9975836 DOI: 10.1103/physrevb.50.14911] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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370
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Tarshis LC, Yan M, Poulter CD, Sacchettini JC. Crystal structure of recombinant farnesyl diphosphate synthase at 2.6-A resolution. Biochemistry 1994; 33:10871-7. [PMID: 8086404 DOI: 10.1021/bi00202a004] [Citation(s) in RCA: 298] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The synthesis of farnesyl diphosphate (FPP), a key intermediate in the isoprenoid biosynthetic pathway required for the synthesis of cholesterol and in the formation of prenylated proteins, is catalyzed by the enzyme farnesyl diphosphate synthase (FPS). The crystal structure of avian recombinant FPS, the first three-dimensional structure for any prenyltransferase, was determined to 2.6-A resolution. The enzyme exhibits a novel fold composed entirely of alpha-helices joined by connecting loops. The enzyme's most prominent structural feature is the arrangement of 10 core helices around a large central cavity. Two aspartate-rich sequences that are highly conserved among the isoprenyl diphosphate synthase family of prenyltransferases, and are essential for enzymatic activity, were found on opposite walls of this cavity, with the aspartate side chains approximately 12 A apart and facing each other. The location and metal ion binding properties of these sequences suggest that the conserved aspartate residues participate in substrate binding of catalysis.
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Yan M, Rothberg LJ, Papadimitrakopoulos F, Galvin ME, Miller TM. Defect quenching of conjugated polymer luminescence. PHYSICAL REVIEW LETTERS 1994; 73:744-747. [PMID: 10057526 DOI: 10.1103/physrevlett.73.744] [Citation(s) in RCA: 183] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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372
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Yan M, Templeton DJ. Identification of 2 serine residues of MEK-1 that are differentially phosphorylated during activation by raf and MEK kinase. J Biol Chem 1994; 269:19067-73. [PMID: 8034665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The signal transduction kinase MEK (mitogen-activated protein (MAP) or extracellular signal-regulated (Erk) kinase)-1 is activated via phosphorylation by MEKK (MEK kinase) and raf kinases. We show here that these two kinases phosphorylate rat MEK-1 exclusively on two serine codons, Ser218 and Ser222. Phosphorylation of MEK-1 on serines 218 and 222 is both necessary and sufficient for MEK-1 to be activated and able to phosphorylate MAP kinase. A mutant form of MEK-1 that replaces these two codons with alanine cannot be activated, and one that substitutes glutamic acid residues in place of these 2 serines is active independent of activation by phosphorylation. These sites of activation occur in a region of MEK-1 that is similar to sites of activating phosphorylation in several other serine/threonine kinases, suggesting that this region may represent a conserved "activating domain" of many kinases. MEKK and raf display differences in site preference between these two codons, with MEKK showing preference for the amino acid at codon 218 and raf phosphorylating each residue approximately equally. This site preference might result in differences in the temporal or subsequent substrate patterns of MEK activation that result from these two activation pathways.
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373
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Yan M, Templeton D. Identification of 2 serine residues of MEK-1 that are differentially phosphorylated during activation by raf and MEK kinase. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)32275-5] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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374
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Yan M, Rothberg L, Hsieh BR, Alfano RR. Exciton formation and decay dynamics in electroluminescent polymers observed by subpicosecond stimulated emission. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:9419-9422. [PMID: 10009740 DOI: 10.1103/physrevb.49.9419] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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375
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Yan M, Cai SX, Wybourne MN, Keana JF. N-hydroxysuccinimide ester functionalized perfluorophenyl azides as novel photoactive heterobifunctional cross-linking reagents. The covalent immobilization of biomolecules to polymer surfaces. Bioconjug Chem 1994; 5:151-7. [PMID: 8031878 DOI: 10.1021/bc00026a007] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The synthesis of N-hydroxysuccinimide (NHS) functionalized perfluorophenyl azides (PFPAs) 2 and 3 is described together with a general method for the covalent modification of polymer surfaces using heterobifunctional, photoactivable cross-linking reagents 1 and 3. The NHS-active ester group becomes covalently attached to the polymer surface via an efficient CH bond insertion reaction of the photogenerated, highly reactive nitrene intermediate derived from the PFPA. The NHS ester is capable of further reaction with a variety of primary amine-containing reagents including biomolecules by way of amide formation. The method is illustrated as follows. Photolysis of polystyrene (PS) and poly-(3-octylthiophene) (P3OT) thin films spin-coated with NHS PFPA ester 1 or 3 gave films 8 or 9, respectively. Each film was then exposed to an aqueous solution of horseradish peroxidase (HRP), giving films 10 or 11, respectively. The amounts of HRP immobilized on PS and P3OT were calculated from enzyme activity assays to be 0.5 +/- 0.1 ng/mm2 for 10a, 1.0 +/- 0.2 ng/mm2 for 11a, 0.2 +/- 0.1 ng/mm2 for 10b, 0.3 +/- 0.1 ng/mm2 for 11b. Using this surface functionalization methodology, biotin-streptavidin-biotin-HRP was constructed on the PS film. The storage stability of HRP thus immobilized through the extended linker, biotin-streptavidin-biotin, was enhanced as compared to that of HRP directly immobilized on the PS surface.
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Yan M, Rothberg LJ, Papadimitrakopoulos F, Galvin ME, Miller TM. Spatially indirect excitons as primary photoexcitations in conjugated polymers. PHYSICAL REVIEW LETTERS 1994; 72:1104-1107. [PMID: 10056618 DOI: 10.1103/physrevlett.72.1104] [Citation(s) in RCA: 161] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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377
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Mei QD, Yan M, Huang XL. [Immunohistochemical study and treatment result of small cell lung carcinoma using combination chemotherapy]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1994; 16:43-6. [PMID: 8033748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Sixty eight cases of small cell lung carcinoma (SCLC) were treated with Combination chemotherapy regimen of COCE or COMP. Among them, 22 cases received radiotherapy after chemotherapy, and 14 cases were studied with antibodies of NSE (neuron-specific enolase), CCH-A (chromogranin A), CEA (carcino-embryonic antigen) and keratin using an immunohistochemical ABC method. The total remission rate was 58.8% and the MST was 12.8 months. The CR+PR of COCE treated group was 74.3% and the MST was 12.9 months. The CR+PR of COMP treated group was 37.8% and the MST was 10 months. There was statistically significant difference between results of the COCE and COMP-treated groups. The MST of cases who received radiotherapy after chemotherapy was 15 months (COCE 17.3 months, COMP 12 months). It indicated that COCE regimen was more effective than COMP one. The immunohistochemical result showed that 44.4% (6/14) of the cases were positive with NSE and/or CCH-A, and their MAT was longer than that of NSE and/or CCH-A negative cases. It suggests that SCLC with neuroendocrine differentiation has a better prognosis.
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Hsu JW, Yan M, Jedju TM, Rothberg LJ, Hsieh BR. Assignment of the picosecond photoinduced absorption in phenylene vinylene polymers. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:712-715. [PMID: 10009349 DOI: 10.1103/physrevb.49.712] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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380
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Hawkins JG, Lee LC, Yan M, Lin Y, Perkins FW, Yamada M. A mechanism to produce a dawn-dusk component of plasma flow during magnetic reconnection in the magnetotail. ACTA ACUST UNITED AC 1994. [DOI: 10.1029/93ja02269] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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381
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Xing SH, Ge XQ, Yan M, Bian CF. [Effects of dl-tetrahydropalmatine on blood pressure and norepinephrine and epinephrine contents in peripheral tissues]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1994; 15:92-6. [PMID: 8010098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Administration of dl-tetrahydropalmatine (THP) i.v., ip, and ig lowered the pressure and concurrently slowed the heart rate in anesthetized rats. The hypotensive and bradycardic effects were not produced by injecting THP into the vertebral artery in anesthetized rabbits. These results suggest that the site of hypotensive action of THP may not be a central one. The HPLC coupled with electrochemical detection showed that the contents of norepinephrine (NE) in the heart, aorta, and femoral artery and epinephrine (E) in the adrenal gland were markedly reduced by THP (P < 0.01). A positive correlation was found between the hypotensive effect and the reduction of NE in the aorta and femoral artery (r = 0.97, P < 0.01).
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382
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Wang W, Yan M, Becker D, Sevilla MD. The influence of hydration on the absolute yields of primary free radicals in gamma-irradiated DNA at 77 K. II. Individual radical yields. Radiat Res 1994; 137:2-10. [PMID: 8265784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In this report we present an electron spin resonance (ESR) investigation of the yields of the individual free radicals formed in gamma-irradiated frozen DNA as a function of hydration and dose at 77 K. Analysis of the ESR spectra taken at low hydration shows that the ion radical composition remains nearly constant with dose and that few secondary radicals are formed even at high doses (above about 50 kGy). For fully hydrated samples, the radical composition changes dramatically with dose. Thymine anion radical (T-.) is found in abundance at low doses but nearly disappears at higher doses, with a corresponding increase in the N-3 deuterated cytosine anion radical (CD.). Guanine cation radical (G+.) decreases at high doses, with a concomitant increase in secondary radical species (S.). Analysis of the dose-response data for G values (the yields in microM/J), k values (the destruction constants) and k' values (a new constant that characterizes the change in G with dose) was performed for each of the DNA base free radicals present at 77 K. The G value for each of the base radicals increases with the hydration level. The k values for CD. and G+. increase slightly with hydration; however, that of T-. increases substantially. Destruction constants for neutral radicals such as TH. and CD. are found to be substantially smaller than those for ion radicals and provide an indication of the radical charge state. A negative k' value for T-. and a positive k' value for CD. are explained in terms of radiation effects that result in the formation of a deuterated cytosine base, i.e., C(N3)D+, which greatly increases cytosine's electron affinity. The ratio of anion radical to cation radical concentrations is found to be about 1.6 and is invariant with hydration. A speculation on the imbalance based on hole-hole combinations in spurs is presented.
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383
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Cai SX, Glenn DJ, Gee KR, Yan M, Cotter RE, Reddy NL, Weber E, Keana JF. Chlorinated phenyl azides as photolabeling reagents. Synthesis of an ortho,ortho'-dichlorinated arylazido PCP receptor ligand. Bioconjug Chem 1993; 4:545-8. [PMID: 8305523 DOI: 10.1021/bc00024a018] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The enhanced photolabeling properties of chlorinated phenyl azides are demonstrated by the synthesis and photolysis of methyl 4-azido-2,3,5,6-tetrachlorobenzoate (3) and methyl 4-azido-3,5-dichlorobenzoate (4). Photolysis of azide 3 in 1 M diethylamine/cyclohexane as the trapping medium gave 34% NH-insertion product. Similar photolysis of azide 4 gave 35% NH insertion product. These results demonstrate that chlorinated phenyl azides are significantly better at undergoing NH insertion than nonhalogenated analogs and suggest that improvement of existing aryl azide-based photolabels might be achieved by introduction of chlorine atoms on either side of the azide group. As an application, 3-azido-2,4-dichloro-10,5-(iminomethano)-10,11-dihydro-5H- dibenzo[a,d]cycloheptene (19), an analog of the potent PCP receptor ligand IDDC (14), was synthesized and its affinity for the PCP receptor was determined to be 6.3 +/- 0.7 microM (IC50 against [3H]MK801).
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384
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Yan M, Sob M, Luzzi DE, Vitek V, Ackland GJ, Methfessel M, Rodriguez CO. Interatomic forces and atomic structure of grain boundaries in copper-bismuth alloys. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 47:5571-5582. [PMID: 10004502 DOI: 10.1103/physrevb.47.5571] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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385
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Jin X, Li J, Yan M. [Flavonoids in the seed of Cuscuta chinensis Lam]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1992; 17:292-4, inside backcover. [PMID: 1418564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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386
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Yan M, Lee LC, Priest ER. Fast magnetic reconnection with small shock angles. ACTA ACUST UNITED AC 1992. [DOI: 10.1029/92ja00170] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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387
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Yan M, Manor D, Weng G, Chao H, Rothberg L, Jedju TM, Alfano RR, Callender RH. Ultrafast spectroscopy of the visual pigment rhodopsin. Proc Natl Acad Sci U S A 1991; 88:9809-12. [PMID: 1946406 PMCID: PMC52810 DOI: 10.1073/pnas.88.21.9809] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We report on time-resolved absorption studies of the bovine visual pigment rhodopsin with subpicosecond resolution at room temperature. Our data show that bathorhodopsin, rhodopsin's early photoproduct, is photochemically formed in 3.0 +/- 0.7 ps. The data suggest that bathorhodopsin formation is kinetically preceded by two species along the rhodopsin-to-bathorhodopsin reaction coordinate. The first is identified with the vertically excited Franck-Condon state. This decays with an approximately 200-fs lifetime to an intermediate, which then decays to bathorhodopsin in 3.0 ps. We assign this intermediate to be an excited state transient near 90 degrees along the 11-12 torsional coordinate of rhodopsin's chromophore. Exchange of rhodopsin's exchangeable protons for deuterons does not affect the observed dynamics. These observations are both qualitatively and quantitatively consistent with molecular dynamics calculations, which model the rhodopsin to bathorhodopsin phototransition as a cis-trans isomerization along the 11-12 torsional coordinate of rhodopsin's chromophore.
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388
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Luzzi DE, Yan M, Sob M, Vitek V. Atomic structure of a grain boundary in a metallic alloy: Combined electron microscope and theoretical study. PHYSICAL REVIEW LETTERS 1991; 67:1894-1897. [PMID: 10044278 DOI: 10.1103/physrevlett.67.1894] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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389
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Yan M, Yin SY. [Primary color P-VEP in diabetic retinopathy]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 1991; 27:200-3. [PMID: 1935442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
148 normal eyes and 123 eyes of diabetic retinopathy patients were examined the red, green, blue primary color and black/white P-VEPs, with the conclusion that the latencies of P100 were significantly delayed in the diabetic group, particularly that of the blue color, which was also in positive correlation with the level of blood sugar and the duration of diabetes. The consistency of blue P-VEP with fluorescein angiographic examination in diabetic retinopathy was good, and the abnormality ratio of the former (73.0%) was higher than that of the latter (60.2%). The results indicated that S-wave cones were damaged more readily than were L-wave cones, and the blue P-VEP was sensitive in monitoring the injury to visual function in diabetes.
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390
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Yan M, Ling YL, Huang SS, Gong SQ, Xu ZX. Changes in pulmonary Cu-Zn contents in superior mesenteric artery occlusion shock of rabbit. Biol Trace Elem Res 1991; 29:281-8. [PMID: 1726410 DOI: 10.1007/bf03032684] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Contents of Cu and Zn of into-pulmonary blood (IPB), out-pulmonary blood (OPB), Lung tissue, and supernatant and macrophages of Lung Lavage were determined in superior mesenteric artery occlusion (SMAO) shock of rabbits. Zn of pulmonary tissue was 11.42 +/- 0.60 and 14.52 +/- 1.78 (micrograms/g wet wt) in SMAO shock and control groups, respectively. Content of Zn was found to be lower, Cu was not changed, and Cu/Zn ratio increased in lung tissue in SMAO shock. Contents of Cu and Zn in other samples were not changed. The results suggest that lower Zn in lung tissue related to acute lung injury.
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391
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Yan M. [Effects of perioperative parenteral nutrition on immunocompetence in patients with gastric cancer]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 1990; 28:739-41, 782. [PMID: 2128263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To elucidate the effects of parenteral nutrition on the immunocompetence, we administrated parenteral nutritional support to the malnourished gastric cancer patients during perioperative periods. Changes of peripheral blood natural killer cytotoxicity (NKC) activity (LDH enzyme-release assay) and T lymphocyte subsets (OKT series monoclone antibody indirect fluorescent assay) were monitored before and after nutritional support. The results showed that one week of pre or postoperative parenteral nutrition significantly increased the NKC activity, T-helper, and T-helper/T-suppressor ratio. The total T lymphocytes count may also increase. T-suppressors remained unchanged no matter whether nutritional support was given or not. The authors believe that perioperative nutritional support could improve the immunocompetence of gastric cancer patients to some extent, and promote the restoration of immune depression caused by operation, but it could not eliminate the effects of immune depressing factor produced by the tumor. Intralipid can be used properly as non protein energy source without immunodepressing effects.
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392
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Liu Y, Yan M, Wang T, Pan M, Zhang W. [Effects of Acanthopanax giraldii Harms on coronary flow in isolated perfused guinea-pig heart and arrhythmia in other animals]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1990; 15:494-6, 513. [PMID: 2093325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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393
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Yan M. [Congestive heart failure treated by a combination of cyclovirobuxine D with digoxin]. ZHONG XI YI JIE HE ZA ZHI = CHINESE JOURNAL OF MODERN DEVELOPMENTS IN TRADITIONAL MEDICINE 1990; 10:88-9, 69. [PMID: 2364468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The patients with congestive heart failure which were treated by combination of digoxin with cyclovirobuxine D were described, with good result, of which prominating effect was 45.5%. Researchful result of 11 patients showed serum concentration of digoxin before and after combined treatment was not obviously different (P less than 0.05). Basis of pharmacokinetics was provided for using combined treatment of these drugs with long time and greater safeness.
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394
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Sevilla MD, Becker D, Yan M. The formation and structure of the sulfoxyl radicals RSO(.), RSOO(.), RSO2(.), and RSO2OO(.) from the reaction of cysteine, glutathione and penicillamine thiyl radicals with molecular oxygen. Int J Radiat Biol 1990; 57:65-81. [PMID: 1967295 DOI: 10.1080/09553009014550351] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
This work reports an electron spin resonance study of the reactions of cysteine, glutathione and penicillamine thiyl radicals with molecular oxygen in frozen aqueous solutions at low temperatures. For all three thiols, the thiyl radical, RS., is found to react with oxygen to form the thiol peroxyl radical, RSOO(.). On the absorption of visible light, RSOO(.) photoisomerizes to the sulfonyl radical, RSO2(.), which subsequently reacts with molecular oxygen to form RSO2OO(.), the sulfonyl peroxyl radical. The identities of the sulfonyl and sulfonyl peroxyl radicals were confirmed by their production by a different route, from sulfinic acid. Sulfinyl radicals, RSO(.), are found as the final radical species in the reactions of thiyl radicals and oxygen. Parallel 17O hyperfine couplings (A parallel) are reported for each sulfoxyl radical and a correlation between the spin density on oxygen and the reactivity of the radical is suggested. As a result of this correlation sulfonyl peroxyl radicals are predicted to be far more reactive than thiol peroxyl radicals. We also report molecular orbital calculations on the nature of the spin density distribution and the molecular geometry of the model radicals CH3SO2(.) and CH3SO2OO(.).
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395
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Jia YK, Luo HC, Zhan L, Jia TZ, Yan M. A study on the treatment of schizophrenia with He-Ne laser irradiation of acupoint. J TRADIT CHIN MED 1987; 7:269-72. [PMID: 3449708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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396
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Yan M. [Senile macular degeneration]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 1987; 23:313-6, 21. [PMID: 3129258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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397
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Yan M, Zhang Z, Lei XH, Xi YR, Xu YX. [Studies on the chemotherapy of filariasis. III. Synthesis of 5-nitro-2-thienylazomethine and 3,5-dinitro-2-thienylamine derivatives]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 1985; 20:219-23. [PMID: 4072690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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398
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Lu JM, Zhang YI, Yan M, Lei XH. [Synthesis and biological activities of some new 3-methyl-5-nitrofuran derivatives]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 1984; 19:660-6. [PMID: 6536177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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399
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Xi YR, Xu YX, Nie JH, Yan M, Zhang Z. [Filaricidal effect of 4 (5-nitrofuryl-2)-methylene amino compounds]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1984; 5:207-11. [PMID: 6239515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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400
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Zhang XP, Yan M, Shi HL, Lei XH. [Chemotherapeutic studies on schistosomiasis. XIV. Synthesis of coumaran derivatives and its analogs]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 1984; 19:306-8. [PMID: 6496108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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