251
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Knop RH, Chen CW, Mitchell JB, Russo A, McPherson S, Cohen JS. Adaptive cellular response to hyperthermia: 31P-NMR studies. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 845:171-7. [PMID: 3995087 DOI: 10.1016/0167-4889(85)90174-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Dynamic intracellular ATP and Pi levels were measured non-invasively for Chinese hamster V79 cells by 31P-NMR under conditions of thermotolerance and heat-shock protein induction. High densities of cells were embedded in agarose strands, placed within a standard NMR sample tube, and perfused with medium maintained either at 37 or 43 degrees C at pH 7.35. Cell survival and heat-shock protein synthesis were assessed either from parallel monolayer cultures or cells dislodged from the agarose strands post-treatment. Thermotolerance (heat resistance) and heat-shock protein synthesis was induced by a 1 h exposure to 43 degrees C followed by incubation for 5 h at 37 degrees C. After the 5 h incubation at 37 degrees C, marked thermal resistance was observed in regard to survival with concomitant synthesis of two major heat-shock proteins at 70 and 103 kDa. Studies were also conducted where tolerance and heat-shock protein synthesis were partially inhibited by depletion of cellular glutathione (GSH) prior to and during heat treatment. Dynamic measurement of intracellular ATP of cells heated with or without GSH depletion revealed no change in steady-state levels immediately after heating or during the 5 h post-heating incubation at 37 degrees C where thermotolerance and heat-shock proteins develop. These data are consistent with other reported data for mammalian cells and indicate that the steady-state ATP levels in mammalian cells remain unchanged during and after the acquisition of the thermotolerant state.
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252
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Borah B, Chen CW, Egan W, Miller M, Wlodawer A, Cohen JS. Nuclear magnetic resonance and neutron diffraction studies of the complex of ribonuclease A with uridine vanadate, a transition-state analogue. Biochemistry 1985; 24:2058-67. [PMID: 4016100 DOI: 10.1021/bi00329a038] [Citation(s) in RCA: 129] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The complex of ribonuclease A (RNase A) with uridine vanadate (U-V), a transition-state analogue, has been studied with 51V and proton NMR spectroscopy in solution and by neutron diffraction in the crystalline state. Upon the addition of aliquots of U-V at pH 6.6, the C epsilon-H resonances of the two active-site histidine residues 119 and 12 decrease in intensity while four new resonances appear. Above pH 8 and below pH 5, these four resonances decrease in intensity as the complex dissociates. These four resonances are assigned to His-119 and His-12 in protonated and unprotonated forms in the RNase-U-V complex. These resonances do not titrate or change in relative area in the pH range 5-8, indicating a slow protonation process, and the extent of protonation remains constant with ca. 58% of His-12 and ca. 26% of His-119 being protonated. The results of diffraction studies show that both His-12 and His-119 occupy well-defined positions in the RNase-U-V complex and that both are protonated. However, while the classic interpretation of the mechanism of action of RNase based on the proposal of Findlay et al. [Findlay, D., Herries, D. G., Mathias, A. P., Rabin, B. R., & Ross, C. A. (1962) Biochem. J. 85, 152-153] requires both His-12 and His-119 to be in axial positions relative to the pentacoordinate transition state, in the diffraction structure His-12 is found to be in an equatorial position, while Lys-41 is close to an axial position. Hydrogen exchange data show that the mobility and accessibility of amides in the RNase-U-V complex do not significantly differ from what was observed in the native enzyme. The results of both proton NMR in solution and neutron diffraction in the crystal are compared and interpreted in terms of the mechanism of action of RNase.
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253
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Zhang JQ, Wang SX, Chen CW. [Biologic and morphologic characteristics of the BCaP-37 human breast cancer cell line]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 1985; 23:241-3, 255. [PMID: 4017778] [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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254
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Chen CW, Braun R, Thomas CA. Mapping of restriction enzyme cuts by a new two-dimensional procedure. EXPERIENTIA 1984; 40:921-3. [PMID: 6088282 DOI: 10.1007/bf01946440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A new procedure has been worked out to establish restriction maps. The method is fast, does not in general require labeled DNA and has been applied to map the linear palindromic rDNA of Physarum with the restriction enzyme Bst EII.
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255
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Fujii S, Nakazono N, Ishii K, Lin CC, Sheu MM, Chen CW, Fujinaga K. Molecular epidemiology of adenovirus type 8 (Ad 8) in Taiwan: four subtypes recovered during the period of 1980-1981 from patients with epidemic keratoconjunctivitis. JAPANESE JOURNAL OF MEDICAL SCIENCE & BIOLOGY 1984; 37:161-9. [PMID: 6098752 DOI: 10.7883/yoken1952.37.161] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Adenovirus type 8 (Ad 8) has been the major and important causative agent of epidemic keratoconjunctivitis (EKC). By enzymatic cleavage analysis with five endonucleases, PstI, HindIII, BamHI, SalI and SstI, 27 out of 149 Ad 8 isolates recovered from patients with EKC during the period from July, 1980 to July, 1981 in Kaohsiung, Taiwan, were studied. By cleavage patterns, 27 Ad 8 isolates in Kaohsiung were classified into four subtypes which were found to be different from the subtypes (Ad 8A, Ad 8B) prevalent in Sapporo (1).
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256
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Knop RH, Chen CW, Mitchell JB, Russo A, McPherson S, Cohen JS. Metabolic studies of mammalian cells by 31P-NMR using a continuous perfusion technique. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 804:275-84. [PMID: 6743691 DOI: 10.1016/0167-4889(84)90130-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Levels of ATP and Pi in metabolically active Chinese hamster lung fibroblasts were monitored noninvasively by 31P-NMR over many hours and under a variety of conditions. The cells were embedded in a matrix of agarose gel in the form of fine threads which were continuously perfused in a standard NMR tube. The small diameter of the thread allows rapid diffusion of metabolites and drugs into the cells. The changes in ATP and Pi levels were followed as a function of time in response to perfusion with a glucose-containing medium, with isotonic saline and with a medium containing 2,4-dinitrophenol, an uncoupler of oxidative phosphorylation. This gel-thread perfusion method should enable routine NMR studies of cellular metabolism, and may have other potential biological applications.
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257
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Wang CS, Hwang TL, Jan YY, Chou FF, Jeng LB, Chen CW, Chen MF. Highly selective vagotomy in the treatment of perforated duodenal ulcer. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1984; 83:470-6. [PMID: 6590780] [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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258
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Chen CW, Cohen JS, Myers CE, Sohn M. Paramagnetic metalloporphyrins as potential contrast agents in NMR imaging. FEBS Lett 1984; 168:70-4. [PMID: 6705923 DOI: 10.1016/0014-5793(84)80208-2] [Citation(s) in RCA: 102] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Several water-soluble paramagnetic metalloporphyrins were found to increase significantly the relaxation rate (1/T1) of water. Such compounds are known to be selectively retained by tumors in animals, and consequently we identify them as potential contrast agents for tumors in NMR imaging.
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259
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Howard FB, Chen CW, Cohen JS, Miles HT. Poly(d2NH2A-dT): effect of 2-amino substituent on the B to Z transition. Biochem Biophys Res Commun 1984; 118:848-53. [PMID: 6704109 DOI: 10.1016/0006-291x(84)91472-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The effect of 2-amino substitution in adenosine (which permits formation of three hydrogen bonds to T) on the B to Z transition was examined in synthetic DNA of alternating purine-pyrimidine sequence. Results of CD, IR, and 31P NMR experiments show that (d2NH2A-dT)n undergoes a cooperative transition to a different helical structure under the same conditions as the B to Z transition of (dG-dC)n.
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260
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Chou FF, Chen MF, Jan YY, Wang CS, Chen CW, Jeng LB. The treatment of leg varicose veins with hypertonic saline--heparin injections. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1984; 83:206-10. [PMID: 6587000] [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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261
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Chen MF, Jan YY, Chou FF, Wang CS, Jeng LB, Chen CW. Use of fiberoptic choledochoscope in common bile duct and intrahepatic duct exploration. Gastrointest Endosc 1983; 29:276-8. [PMID: 6642159 DOI: 10.1016/s0016-5107(83)72631-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This report summarizes our experience with 339 consecutive flexible fiberoptic choledochoscopic examinations performed in the course of 598 common bile duct explorations for biliary tract stones. Routine choledochoscopy added 5 to 10 minutes to the operation and caused no complications. In 81 of the patients, additional stones were discovered with choledochofiberscopy after completion of routine bile duct exploration. Postoperative cholangiography demonstrated a retained stone in 57 patients (two in the common bile duct and 55 in the intrahepatic ducts). Forty-two patients with stones retained in the intrahepatic ducts were diagnosed during operation with the fiberoptic choledochoscope, but those stones were very difficult for us to remove. The accuracy of postexploratory choledochoscopy in diagnosis of stones in the common bile duct and intrahepatic ducts was 99.0% and 90.5%, respectively. Choledochofiberscopy is useful in exploration of the common bile duct and a safe procedure in the diagnosis of biliary tract stones during operation.
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262
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Wang CS, Chou FF, Jan YY, Jeng LB, Chen CW, Chen PC, Chen MF. The early results of highly selective vagotomy plus pyloric dilatation or pyloroplasty for obstructing duodenal ulcers. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1983; 82:1187-95. [PMID: 6584545] [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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263
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Chen MF, Jan YY, Chou FF, Wang CS, Chen CW, Jeng LB, Huang CL. [Fatal complication in biliary surgery for cirrhotic patients]. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1983; 82:977-81. [PMID: 6418851] [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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264
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Abstract
Genomic DNA that has been digested with a restriction endonuclease and fractionated by electrophoresis on an agarose gel can be recovered on glass-fiber filters by a new blotting scheme. The DNA fragments in each fraction are then digested with a second restriction nuclease and then separated on a slab gel, resulting in a two-dimensional display of the restriction fragments. This rapid fingerprinting technique is useful in the analysis of complex genomes and in the isolation and cloning of particular sequences.
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265
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Chen CW, Cohen JS. Salt- and sequence-dependence of the secondary structure of DNA in solution by 31P-NMR spectroscopy. Biopolymers 1983; 22:879-93. [PMID: 6850053 DOI: 10.1002/bip.360220310] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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266
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Chen MF, Chang CH, Chou FF, Wang CS, Jan YY, Hsieh MJ, Jeng LB, Chen CW. [Experiences with the EEA stapling instrument for esophageal anastomosis]. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1983; 82:461-6. [PMID: 6577140] [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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267
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Chen MF, Chou FF, Wang CS, Jan YY, Jeng LB, Chen CW. [Spontaneous biliary enteric fistula]. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1983; 82:308-13. [PMID: 6576104] [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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268
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Chen CW, Jeng LB, Jan YY, Wang CS, Chou FF, Cheng MF. [Blunt abdominal trauma: a review of 217 cases undergoing surgery]. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1983; 82:321-6. [PMID: 6576106] [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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269
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Chou FF, Wang CS, Jeng LB, Chen CW, Chen JS, Jan YY, Chen MF. [Treatment of bleeding esophageal varices by esophageal transection with E.E.A. instrument]. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1982; 81:1382-7. [PMID: 6984458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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270
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Chen MF, Jan YY, Chou FF, Wang CS, Jeng LB, Chen CW. [Evaluation of operative choledochofiberscopy]. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1982; 81:1136-9. [PMID: 6960148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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271
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Jeng LB, Chen CW, Jan YI, Chou FF, Wang CS, Chen MF. [Diagnostic peritoneal lavage in abdominal trauma]. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1982; 81:1132-5. [PMID: 6960147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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272
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Chen CW, Huang FY. [Severe mycoplasmal pneumonia--report of 2 cases]. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1982; 81:1081-5. [PMID: 6960138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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273
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Smith SS, Yu JC, Chen CW. Different levels of DNA modification at 5'CCGG in murine erythroleukemia cells and the tissues of normal mouse spleen. Nucleic Acids Res 1982; 10:4305-20. [PMID: 6289271 PMCID: PMC320801 DOI: 10.1093/nar/10.14.4305] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The DNA of a Friend erythroleukemic cell line (clone DS-19) and that of mouse spleen from which it was derived were compared with respect to modification at 5'CCGG. Methylation patterns in clone DS-19 DNA were very different from those in normal spleen DNA. Our results suggest that the mechanism by which the internal cytosine in the 5'CCGG sequence is modified has been partially inactivated in clone DS-19. We observed a general decrease of about two-fold in total modification at this site in DS-19 DNA. This general decrease was shown to extend to 5'CCGG sites in specific classes of repeated sequences with two-dimensional displays of restriction fragments. Interspersed repeated sequences which are concertedly modified (i.e., modified at many different chromosomal locations) in spleen, were found to be unmodified at these locations in the cell line. However, we did not detect a difference in DNA modification at 5'CCGG with these techniques when uninduced and hexamethylene-bis-acetamide (HMBA) induced cells of clone DS-19 were compared. In other experiments, we obtained further evidence that selected classes of repeated sequences in Physarum polycephalum are methylated to the same extent independent of chromosomal location.
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274
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Chen CW, Breckinridge JB. Holographic Twyman-Green interferometer. APPLIED OPTICS 1982; 21:2563-2568. [PMID: 20396076 DOI: 10.1364/ao.21.002563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A dichromated gelatin off-axis Fresnel zone plate (OFZP) was designed, fabricated, and used in a new type of interferometer for optical metrology. This single hologram optical element combines the functions of a beam splitter, beam diverger, and aberrated null lens. Data presented show the successful application for an interferometric test of an f/6, 200-mm diam parabolic mirror.
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275
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Chen MF, Wang CS, Chou FF, Jan YY, Jeng LB, Chen CW. [A clinical analysis of fulminating acute cholangitis]. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1982; 81:745-51. [PMID: 6958802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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