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Chen TC, Humpierres J, Hanna D, Perregaux SB, Puschett JB. Volume expansion-induced changes in renal tubular membrane protein phosphorylation. Biochem Biophys Res Commun 1987; 143:74-80. [PMID: 3827931 DOI: 10.1016/0006-291x(87)90631-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The influence of volume expansion (VE) on the in vitro phosphorylation of membrane protein in the proximal brush border membrane (BBM) of the thyroparathyroidectomized (TPTX) rat was studied in the presence and absence of cyclic AMP and the results were compared to those obtained in control TPTX and intact animals. The results indicate that the cyclic AMP-independent phosphorylation of a protein band (Mr = 72,000) was stimulated both by VE and by the presence of parathyroid hormone in the circulation, whereas the cyclic AMP-dependent phosphorylation of membrane proteins (Mr = 40,000, 52,000 and 87,000) was inhibited by the same maneuvers. These findings, taken together with data previously available, which demonstrate inhibition of BBM phosphate transport following VE, may provide a link between alterations in phosphate transport in renal BBM vesicles and the phosphorylation of membrane proteins. The results further suggest that membrane protein phosphorylation may be a common mechanism by which a number of agents and maneuvers induce an inhibition of renal tubular phosphate transport.
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302
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Chen TC, Kuo JS. [Evaluation of the relation of distal surface caries of the mandibular second molar with the mandibular third molar]. CHANGGENG YI XUE ZA ZHI 1986; 9:186-93. [PMID: 3454710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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303
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Badimon JJ, Kottke BA, Chen TC, Chan L, Mao SJ. Quantification and immunolocalization of apolipoprotein E in experimental atherosclerosis. Atherosclerosis 1986; 61:57-66. [PMID: 3730054 DOI: 10.1016/0021-9150(86)90113-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We developed a radioimmunoassay for rabbit apolipoprotein E (apo E) for studying their plasma apo E levels and its accumulation in the aorta of rabbits fed a cholesterol diet. Delipidation of plasma did not increase the apo E immunoreactivity and this immunoreactivity was indistinguishable from that in an apo E-phospholipid complex. The antigenic determinants of apo E in lipoprotein particles were therefore fully reacted with our goat anti-apo E antibodies. In our assay system, the non-ionic detergent Tween-20 was found to be necessary to significantly reduce the non-specific binding of 125I-labeled apo E to polystyrene tubes, and yet not interfere with the assay. In rabbits (n = 6) fed a high cholesterol (1%) diet, plasma apo E increased at least 10-fold above baseline levels and reached maximal levels within 17-20 days after the onset of cho-diet feeding. These levels were sharply reduced only 10 days after resuming a normal diet. Plasma total cholesterol levels went through a similar pattern. Thus, the plasma cholesterol concentration can simply be used to monitor the increase of apo E in cholesterol-fed rabbits. All the cholesterol-fed rabbits developed atherosclerotic fatty streak lesions and apo E located mostly in the thoracic region and was significantly correlated with the accumulation of lipids in the areas of lesion. In addition, the apo E deposition was limited to the aortic areas where lipids were present. On the other hand, apo A-I was not detectable in any lesion area. Our data suggest that apo E or apo E-containing lipoproteins, may be involved in the development of atherosclerosis in cholesterol-fed rabbits.
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304
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Chen TC. [Studies on a new technic for performing end colostomy using an auto suture]. IGAKU KENKYU. ACTA MEDICA 1985; 55:103-7. [PMID: 3907244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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305
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Chen KH, Cann H, Chen TC, Van West B, Cavalli-Sforza L. Genetic markers of an aboriginal Taiwanese population. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 1985; 66:327-37. [PMID: 3857010 DOI: 10.1002/ajpa.1330660310] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A group of Taiwan aborigines, the Toroko, was typed for 21 classical genetic loci. This is part of an ongoing program aimed at a comprehensive study of Taiwan aborigines. In this first paper a short summary of historical, archeological, and anthropological data in the literature is made, and results of the present survey are compared with older results from other aborigine tribes. An analysis of other neighboring populations from southeast Asia has also been carried out in order to give a preliminary answer to the question of origin of Taiwanese aborigines. Fifteen populations were studied for 13 loci by tree analysis, principal components, and isolation by distance. Tree analysis and principal component analysis gave results in fairly good agreement and indicate three major population clusters: a northeast cluster (Ainu, Korea, Japan, and Ryukyu); a southeast cluster (south China, Thailand, Vietnam, Philippines, Taiwan, and Toroko); and a third cluster including Malaya and Borneo. The positions of Polynesia, Micronesia, and Melanesia are somewhat peripheral. Analysis of the tree shows some potential cases of convergence, perhaps owing to admixture, and of divergence. The analysis of isolation by distance shows that geographic propinquity is a reasonably good predictor of general similarity in this area.
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306
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Chang FY, Chen TC, Lee SK. Real-time ultrasonography in the diagnosis of pancreatic tumors. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1985; 84:204-11. [PMID: 3891910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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307
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Chen TC, Mullen JP, Meglin NJ. Modulation of 1,25-dihydroxyvitamin D3 receptor by phospholipids and fatty acids. J Lipid Res 1984; 25:1306-12. [PMID: 6099395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The structural relationship between several lipids and their respective capacities to inhibit the specific binding of [3H]-1,25 (OH)2 vitamin D3 to chick intestinal cytosol preparations was investigated. The lipids investigated were: synthetic 3-sn-phosphatidylcholine and 3-sn-phosphatidic acid, egg yolk 3-sn-phosphatidylcholine and its corresponding phosphatidic acid, and free unsaturated fatty acids and their esters. The results indicate that at least three structural elements in the phospholipid molecule appear to be important; these are: 1) the structure of the fatty acid, 2) the anionic properties of the phospholipid phosphate group, and 3) the glycerol phosphate portion of the molecule. Our data also demonstrate that the position (1 or 2) and the amount (single vs. double) of unsaturated fatty acids in the phospholipid molecule do not play a major role in the receptor-1,25 (OH)2 vitamin D3 interaction. Furthermore, under equilibrium conditions, kinetic and Scatchard analysis suggest that phospholipids or free fatty acids may bind at a site different from the 1,25 (OH)2 vitamin D3 binding site, and therefore inhibit the hormone binding via a noncompetitive conformational change in the receptor molecule. A model for this phospholipid/free fatty acid binding site is proposed.
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308
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Dominguez JH, Pitts TO, Brown T, Puschett DB, Schuler F, Chen TC, Puschett JB. Prostaglandin E2 and parathyroid hormone: comparisons of their actions on the rabbit proximal tubule. Kidney Int 1984; 26:404-10. [PMID: 6597316 DOI: 10.1038/ki.1984.189] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Recent studies demonstrated that prostaglandin E2 (PGE2) participates in the regulation of glomerular and distal tubular function. A functional role for PGE2 on the proximal tubule has only recently been explored. Thus, we reported that PGE2 antagonizes the phosphaturic effect of PTH in the dog, which suggests that PGE2 may influence the transport functions of the mammalian proximal tubule. The present studies were designed to examine the direct effect of parathyroid hormone (PTH) and PGE2 on the fluxes of fluid (Jv) and phosphate (Jl-b PO4) in the rabbit proximal convoluted and straight tubules (PCT and PST). The activation of adenylate cyclase by the two agents was also examined. Finally, the combined effects of PTH and PGE2 on Jv and Jl-b PO4 were also studied in the PST. In the PCT, PTH (1 microgram/ml) inhibited Jv by 31% (P less than 0.05) but did not alter Jl-b PO4. PGE2 (10(-5) M) failed to act on either Jv or Jl-b PO4. In this segment, PTH stimulated adenylate cyclase but PGE2 did not. In the PST, PTH (1 microgram/ml) inhibited Jv and Jl-b PO4 by 34 and 20%, respectively (P less than 0.01). PGE2 (10(-5) M) also inhibited Jv and Jl-b PO4, by 33 and 12%, respectively (P less than 0.02). In contrast, PGF2 alpha, a related prostanoid, failed to influence these transport parameters. In the PST, PTH activated adenylate cyclase but PGE2 failed to do so. When both PTH (1 microgram/ml) and PGE2 (10(-7) M) were present simultaneously, Jv and Jl-b PO4 were comparable to that seen during control collections.(ABSTRACT TRUNCATED AT 250 WORDS)
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309
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Chang FY, Wang WB, Chen TC. Serum alpha-fetoprotein in nonneoplastic liver diseases. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1984; 83:765-72. [PMID: 6084045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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310
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Chang FY, Wang WB, Chen TC, Fong MS, Ma HW, Tu YC. [Arteriovenous malformation of stomach--a case report]. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1983; 82:476-80. [PMID: 6604131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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311
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Chen TC, De Figueiredo RJ. An image transform coding scheme based on spatial domain considerations. IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE 1983; 5:332-337. [PMID: 21869116 DOI: 10.1109/tpami.1983.4767395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Image transform coding is first briefly reviewed using conventional viewpoints. Then a new spatial domain interpretation is given to image transform coding. An improvement based on this viewpoint for the Fourier transform coding, which possesses simple spatial domain relations, is presented.
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312
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McGowan JA, Chen TC, Fragola J, Puschett JB, Rosenblatt M. Parathyroid hormone: effects of the 3-34 fragment in vivo and vitro. Science 1983; 219:67-9. [PMID: 6849118 DOI: 10.1126/science.6849118] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The biologically active fragment ofparathyroid hormone, consisting of residues 1-34, and its in vitro antagonist, fragment 3-34, were administered separately or in combination to chronically thyroparathyroidectomized dogs. These fragments were also studied in vitro with dog renal cortical membranes. Fragment 3-34 inhibited the stimulation of adenylate cyclase by fragment 1-34 in vitro, but had no agonist or antagonistic effects on renal phosphate transport in vivo.
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313
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Winaver J, Fragola J, Chen TC, Sylk DB, Robertson JS, Puschett JB. Potentiation by calcium of the proximal tubular transport effects of parathyroid hormone. MINERAL AND ELECTROLYTE METABOLISM 1982; 8:275-88. [PMID: 6300634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Previous studies from this laboratory have demonstrated that a low ('physiological') dose of parathyroid hormone (PTH) effects a phosphaturia in chronically thyroparathyroidectomized (TPTX), hypocalcemic dogs, similar in magnitude to that seen in normal intact animals, without altering proximal tubular reabsorption. In addition, cyclic AMP did not increase following this amount of PTH, despite the phosphaturia. Since calcium is an important modulator of transport events, we studied the effects of restoring serum calcium (Ca) to normal before administering a physiological dose of PTH (0.3-0.5 U/kg). In hypocalcemic dogs given only physiological amounts of PTH, percentage phosphate excretion (%EPO4) rose from 3.81 +/- 1.48 to 18.29 +/- 5.69% (p less than 0.025) without any alteration in proximal tubular function. Ca infusion alone likewise did not change %EPO4 or proximal tubular transport. However, calcium-infused dogs given a physiological dose of PTH showed a reduction in proximal tubular fractional phosphate reabsorption from 0.73 +/- 0.04 to 0.63 +/- 0.04 (p less than 0.005), as well as an increase in %EPO4 (from 5.64 +/- 1.69 to 15.86 +/- 2.82%, p less than 0.001), without any increase in urinary or tissue cyclic AMP. We conclude that the elevation of the serum Ca to normal restores the ability of PTH in physiological amounts to alter proximal tubular PO4 transport. The data also suggest that this action of PTH is mediated by Ca, rather than by the adenylate cyclase system.
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314
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Chang FY, Chen CF, Chen TC, Fong MS. [Primary small intestinal malignancies]. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1982; 81:1056-61. [PMID: 6960134] [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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315
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Winaver J, Chen TC, Fragola J, Robertson G, Slatopolsky E, Puschett JB. Alterations in renal tubular water transport induced by parathyroid hormone: evidence for both antidiuretic hormone-mediated and independent effects. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 1982; 99:457-73. [PMID: 6278038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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316
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Abstract
This paper deals with occupational exposure in the academic sector of the Republic of China during the past two decades. The Tsing-Hua film badges were used for personnel monitoring. The radiation sources available in the research institutes and universities are listed and illustrated. The number, sex, age and per capita dose equivalent for the radiation workers in the past 21 yr are analyzed. The radioisotope production rate and the dose equivalent received by the workers are compared, and the results indicate that radiation protection has been greatly improved during last decade.
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317
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Chang FY, Chen TC, Fong MS, Lin S, Yeh SH. Alphafetoprotein levels measured by radioimmunoassay in various liver malignancies. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1982; 81:224-31. [PMID: 6178794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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318
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Puschett JB, McGowan J, Fragola J, Chen TC, Rosenblatt M, Keutmann H. Difference in renal tubular transport effects of 1-34 and 1-84 parathyroid hormone (PTH). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1982; 151:81-2. [PMID: 7180673 DOI: 10.1007/978-1-4684-4259-5_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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319
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Weber MA, Drayer JI, Priest RT, Chen TC. Participation of the renin system in treatment-resistant hypertension as measured by acute blockade of the angiotensin converting enzyme. Am J Nephrol 1982; 2:6-11. [PMID: 6295161 DOI: 10.1159/000166575] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The acute blood pressure response to the angiotensin converting enzyme inhibitor, captopril, was used to measure participation of the renin-angiotensin system in treatment-resistant hypertension. By 2 h after a single 25-mg oral captopril dose in patients still receiving a diuretic-vasodilator-beta-blocker combination, systolic and diastolic blood pressures had fallen significantly; the decrease in diastolic pressure correlated with the control (immediately pre-captopril) plasma renin activity (r = 0.64, p less than 0.001). Apart from its possible contribution to the underlying hypertension, this captopril-identified renin component may have reflected diuretic and vasodilator-induced renin stimulation that could not adequately be prevented by the renin-lowering properties of the beta-blocker. Captopril, and perhaps other specific antirenin drugs, therefore, may be valuable adjuncts to treatment in patients with hypertension refractory to conventional therapy.
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320
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Chen TC, Puschett JB. Modulation of parathyroid hormone-sensitive adenylate cyclase and arginine vasopressin-sensitive adenylate cyclase by calcium and GTP. Arch Biochem Biophys 1981; 212:660-7. [PMID: 6798940 DOI: 10.1016/0003-9861(81)90410-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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321
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Dominguez JH, Chen TC, Fragola J, Puschett JB. Inhibition of the renal tubular effects of parathyroid hormone on phosphate transport by prostaglandin E2. Endocrinology 1981; 109:2267-9. [PMID: 6946926 DOI: 10.1210/endo-109-6-2267] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The infusion of PGE2 into TPTX dogs abolishes the phosphaturic action of PTH in vivo. This effect occurs only if PGE2 infusion precedes the administration of PTH. The infusion of PGE2 in vivo induces a state of refractoriness of PTH-sensitive adenylate cyclase in renal middle medulla from TPTX dogs in vitro. These results suggest that PGE2 inhibits the biological effects of PTH, in part by altering the events related to PTH activation of renal adenylate cyclase. These effects of PGE2, a local mediator, suggest that the renal tubular cell may modulate its responses to multiple and antagonistic stimuli by altering local renal prostaglandins.
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322
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Chen TC, Puschett JB. Evidence for an endogenous parathyroid hormone-sensitive adenylate cyclase activator. Biochem Biophys Res Commun 1981; 100:1471-6. [PMID: 7295311 DOI: 10.1016/0006-291x(81)90684-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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323
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Chen TC, Weber MA. Effects of di-isopropylfluorophosphate and isopropanol on the measurement of plasma renin activity. Clin Chim Acta 1980; 107:217-22. [PMID: 7002369 DOI: 10.1016/0009-8981(80)90449-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Since the protease inhibitor, di-isopropylfluorophosphate (DFP), inhibits the cryoactivation of inactive renin, its addition to stored plasma should prevent unintended renin activation and thereby minimize this source of inaccuracy in the assay of plasma renin activity. However, we have found that 6 mmol/l DFP in stored frozen plasma actually reduced plasma renin activity from 4.89 +/- 0.13 (S.D.) to 2.48 +/- 0.17 ng . ml-1 . h-1 (p < 0.001). This effect did not occur if DFP was added immediately before assay, suggesting that the decreased renin activity reflected an action of DFP on components of the renin system during storage rather than any interference with the assay method itself. The organic solvent isopropanol, which is required to dilute the DFP, appeared responsible for this phenomenon, for when the isopropanol alone, in concentrations of 20 and 40 microliter/ml, was added to stored frozen plasma it decreased plasma renin activity from 3.6 +/- 0.3 to 2.2 +/- 0.1 and 0.6 +/- 0.1 ng . ml-1 . h-1, respectively (p < 0.001 in each case). Correspondingly, plasma renin substrate concentrations were decreased to 71% and 6% of control, indicating that the renin activity reductions produced by isopropanol were due to its denaturation of substrate. Moreover, addition of exogenous sheep renin substrate (1400 ng/ml) immediately before assay restored plasma renin activity to control. Thus, although DFP effectively prevents inadvertent renin activation in stored frozen plasma, it would seem important that subsequent assays for plasma renin activity be performed in the presence of added exogenous substrate.
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324
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Chen TC, Knapp RD, Rohde MF, Brainard JR, Gotto AM, Sparrow JT, Morrisett JD. Magnetic resonance studies of apolipoprotein C-I nitroxide labeled or [13C]methyl enriched at methionine-38. Biochemistry 1980; 19:5140-6. [PMID: 6257278 DOI: 10.1021/bi00563a032] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
One of the three proposed lipid-binding regions of the human apolipoprotein C-I (apo-C-I) is an amphipathic helix which extends from residue 33 to residue 53 and includes a single methionine at sequence position 38. The involvement of the sequence around methionine-38 in phospholipid binding has been evaluated with paramagnetic and nuclear reported groups attached to the thiomethyl moiety. This moiety has been spin-labeled with N-(2,2,6,6-tetramethylpiperidinyl-1-oxy)bromoacetamide or 13C enriched with 13CH3I. As determined from its EPR spectrum, the nitroxide at Met-38 of apoC-I had a rotational correlation time (tau C) of 0.22 ns. When dimyristoylphosphatidylcholine (DMPC) was bound to the spin-labeled apoprotein, tau c increased to 0.35 ns, indicating decreased motion for the methionyl side chain. The line width (nu 1/2) and spin--lattice relaxation time (T1) for the thiomethyl resonance of 13C-enriched apoC-I in 10 mM phosphate buffer was 6.0 Hz and 320 ms, respectively. When the protein solution was made 1.6 M in Gdn-HCl, these values changed to 2.6 Hz and 970 ms, respectively. Upon addition of DMPC multilamellar liposomes to [13C]apoC-I in 1.6 M Gdn-HCl, the line width increased to 4.7 Hz and the T1 decreased to 380 ms. These results strongly suggest that methionine-38 of apoC-I resides in a region of the apoprotein which undergoes significant secondary and/or tertiary structural change upon disaggregation/unfolding in Gdn-HCl and upon interaction with phospholipid.
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325
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Chen TC, Rosenblatt M, Puschett JB. Effects of calcium on a parathyroid hormone-sensitive adenylate cyclase inhibitor. Biochem Biophys Res Commun 1980; 94:1227-32. [PMID: 6772185 DOI: 10.1016/0006-291x(80)90550-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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326
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Howell WL, Chen TC. Supraorbital opacity pulses during carotid artery compression: a method for the detection of carotid obstruction. IEEE Trans Biomed Eng 1980; 27:84-7. [PMID: 7353899 DOI: 10.1109/tbme.1980.326711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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327
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Cote TE, Chen TC, Kebabian JW. Guanosine triphosphate: an endogenous compound in the rabbit cerebellar cortex which couples the beta-adrenergic receptor to adenylate cyclase. Brain Res 1980; 181:127-38. [PMID: 6243221 DOI: 10.1016/0006-8993(80)91263-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The guanyl nucleotides GTP and GDP are endogenous factors in the rabbit cerebellum which contribute to the in vitro coupling of the beta-adrenergic receptor to adenylate cyclase. Repeated washing of the particulate material removes these endoactivity to beta-adrenergic agonists. The endogenous GTP and GDP, isolated by high pressure liquid chromatography, mimic the ability of the supernatant both to restore the coupling of receptor and enzyme and to increase basal enzyme activity. The effectiveness of GDP reflects its conversion to GTP during the assay. GTP does not affect either the number of [3H]dihydroalprenolol binding sites or the affinity of these sites for L-isoproterenol; furthermore, GTP does not cause a shift in activation affinity of enzyme activity for isoproterenol. Thus, the guanyl nucleotides are endogenous constituents of the mammalian brain which are essential for the functional 'coupling' of beta-adrenergic receptors to adenylate cyclase.
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328
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Chen TC, Cote TE, Kebabian JW. Endogenous components of the striatum confer dopamine-sensitivity upon adenylate cyclase activity: the role of endogenous guanyl nucleotides. Brain Res 1980; 181:139-49. [PMID: 7350949 DOI: 10.1016/0006-8993(80)91264-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Repeated washing of the particulate material from rat striatum abolishes the dopamine-sensitivity of the adenylate cyclase activity. Readdition of the soluble fraction of the caudate homogenate restores the dopamine-sensitivity to the enzyme activity. Fractions, prepared with thin layer chromatography, containing endogenous GTP and GDP also restore dopamine-sensitivity to striatal adenylate cyclase activity. The effectiveness of GDP results from its conversion to GTP during the assay; when this conversion is eliminated, GDP can specifically block the coupling between the dopamine receptor and adenylate cyclase.
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329
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Chen TC, Bradley WA, Gotto AM, Morrisett JD. Binding of the chemical carcinogen, p-dimethylaminoazobenzene, by human plasma low density lipoproteins. FEBS Lett 1979; 104:236-40. [PMID: 225207 DOI: 10.1016/0014-5793(79)80822-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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330
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Chen TC, Sparrow JT, Gotto AM, Morrisett JD. Apolipoprotein A-II: chemical synthesis and biophysical properties of three peptides corresponding to fragments in the amino-terminal half. Biochemistry 1979; 18:1617-22. [PMID: 218625 DOI: 10.1021/bi00575a037] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Three peptide fragments of apolipoprotein A-II corresponding to residues 17--31, 12--31, and 7--31 have been synthesized by solid-phase techniques and purified to apparent homogeneity. Each of these fragments contains residues 18--30, a region previously proposed to possess potential amphipathic helical properties. Secondary structural changes of these synthetic fragments accompanying their interaction with phospholipid have been studied by circular dichroism. The magnitude of this interaction has been evaluated from the yields and stoichiometry of lipid-protein complexes isolated by density gradient ultracentrifugation. Fragment 17--31, the smallest peptide containing the proposed amphipathic helix, did not interact with dimyristoylphosphatidylcholine (DMPC) single bilayer vesicles at 24 degrees C; upon addition of DMPC, no ellipticity change could be detected nor could a stable lipid-peptide complex be isolated. However, fragments 12--31 and 7--31 did interact with phosphilipid; in the absence of lipid, both fragments had primarily disordered structures, but when isolated as DMPC-peptide complexes, both fragments possessed increased helical structure. The phospholipid:peptide molar ratio was 14:1 for fragment 12--31 and 27:1 for fragment 7--31. Studies of space-filling models of these fragments suggest that hydrophobicity and/or length are important properties of phospholipid binding apoproteins.
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331
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Chen TC, Ray DS. Replication of bacteriophage M13. XIV. Differential inhibition of the replication of M13 and M13 miniphage in a mutant of Escherichia coli defective in the 5' leads to 3' exonuclease associated with DNA polymerase I. J Virol 1978; 28:679-85. [PMID: 366176 PMCID: PMC525791 DOI: 10.1128/jvi.28.3.679-685.1978] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Previous studies have shown that M13 single-strand synthesis is inhibited at nonpermissive temperature in Escherichia coli polAexl, a temperature-sensitive mutant defective in the 5' leads to 3' exonuclease activity of polymerase I (T.-C. Chen and D. S. Ray, J. Mol. Biol. 106:589-604, 1976). Under these conditions the formation of covalently closed replicative form (RF) molecules is greatly reduced, and miniature forms of RF accumulate. We show here that the accumulation of mini-RFs is the consequence of a differential inhibition of the replication of unit-length phage and preexisting miniphage rather than a de novo production of miniphage. Mini-RFs do not accumulate even after as many as nine cycles of growth in the mutant host infected only with unit-length phage. Mixed infections of the mutant host with plaque-purified unit-length phage and a single cloned miniphage show that discontinuities in the mini-RFs are joined with higher efficiency than are those contained in unit-length RFs. After a shift to nonpermissive temperature during single-strand synthesis in cells infected with plaque-purified phage alone, M13 RFs are found largely as RFII molecules (RF form having one or more single-strand discontinuities) containing only a single discontinuity in the viral strand. The inability of the accumulated unit-length RFII molecules to actively replicate may reflect the presence of either a bound protein or RNA primer on the 5' terminus of the viral strand and provides further support for the existence of distinct initiation and termination events in the synthesis of the viral strand.
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332
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Chen TC, Ray DS. Replication of bacteriophage M13. XIII. Structure and replication of cloned M13 miniphage. J Mol Biol 1978; 125:107-21. [PMID: 731688 DOI: 10.1016/0022-2836(78)90340-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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333
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Chen TC, Ray DS. Replication of bacteriophage M13. X. M13 replication in a mutant of Escherichia coli defective in the 5' leads to 3' exonuclease associated with DNA polymerase I. J Mol Biol 1976; 106:589-604. [PMID: 789894 DOI: 10.1016/0022-2836(76)90253-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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334
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Wang PL, Day EJ, Chen TC. Microbiological quality of frozen fried chicekn product obtained from a retail store. Poult Sci 1976; 55:1290-3. [PMID: 986046 DOI: 10.3382/ps.0551290] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Two brands of frozen fried chicken products were purchased monthly from a local supermarket for six months. Microbiological qualities of these samples were studied. The log number of mesophilic counts ranged from 2.90/g. to 4.78/g; log psychrophilic counts varied from 2.74/g. to 4.66/g.; and log Staphylococcus- 110 medium counts ranged from 2.84/g. to 4.54/g. Mean log microbial counts were higher in brand A samples than in brand B samples. No yeast or mold was detected and all samples were Salmonella negative. Most samples were negative in coliform test, except five samples had coliform MPN ranging from 0.5/g to 0.8/g. A total of 144 isolates of psychrophiles from 12 samples was tentatively identified to be members of Staphylococcus species. About 82.2% of the isolates belong to the Subgroup VI Staphylococcus according to Baird-Parker's classification. Another 17.8% of the isolates resembled Subgroup vi Staphylococcus except in phosphatase test.
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335
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Wang KY, Chang SF, Peng CF, Chen TC. Studies on shigella isolated in southern Taiwan. ZHONGHUA MINGUO WEI SHENG WU XUE ZA ZHI = CHINESE JOURNAL OF MICROBIOLOGY 1976; 9:13-8. [PMID: 1036983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
During 1969, a total of 1,476 fecal and rectal swab specimens was collected from children with diarrhea and 249 strains of shigella were isolated. The incidence was 16.9%. The serotypes of 249 strains were: Shigella dysenteriae, 1.6% (4 strains); S. flexneri, 73.1% (182 strains); S. boydii, 3.2 (8 strains) and S. sonnei, 22.1% (55 strains). There was no marked difference of the isolation rate throughout the whole year. The susceptibility of shigella isolates to chemotherapeutic agents were also investigated. The percentage of the strains susceptible to gentamicin was 97.2%; to cephaloridine, 93.2%; to kanamycin, 91.9%; to colistin, 91.6%; to hetacillin, 88.4%; to ampicillin, 82.4% and to nalidixic acid, 79.9%. The other tested chemotherapeutic agents were less effective.
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336
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Li CL, Ahlberg D, Lansdell H, Gravitz MA, Chen TC, Ting CY, Bak AF, Blessing D. Acupuncture and hypnosis: effects on induced pain. Exp Neurol 1975; 49:272-80. [PMID: 1183526 DOI: 10.1016/0014-4886(75)90210-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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337
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Chen TC, Levin RE. Isolation of Aeromonas sp. ATCC 29063, a phenol-producing organism, from fresh haddock. Appl Microbiol 1975; 30:120-2. [PMID: 1147610 PMCID: PMC187129 DOI: 10.1128/am.30.1.120-122.1975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Attempts to isolate phenol-producing organisms from stale haddock fillets failed. Several such isolates, however, were readily obtained from fresh haddock and were designated Aeromonas sp. Phenol was produced from L-tyrosine by these isolates.
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338
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Chen TC, Levin RE. Taxonomic significance of phenethyl alcohol production by Achromobacter isolates from fishery sources. Appl Microbiol 1974; 28:681-7. [PMID: 4422523 PMCID: PMC186797 DOI: 10.1128/am.28.4.681-687.1974] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The formation of phenethyl alcohol from L-phenylalanine and ethanol by achromobacter isolates of fishery origin was found to be taxonomically significant for such organisms. Phenylpyruvate, the direct oxidative deamination product of L-phenylalanine, was found to serve as an intermediate precursor to phenethyl alcohol formation. Among ten Acinetobacter isolates examined, none produced phenethyl alcohol. Among nine Moraxella isolates examined, one produced phenethyl alcohol.
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339
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Chen TC, Nawar WW, Levin RE. Identification of major high-boiling volatile compounds produced during refrigerated storage of haddock fillets. Appl Microbiol 1974; 28:679-80. [PMID: 4424674 PMCID: PMC186796 DOI: 10.1128/am.28.4.679-680.1974] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The two major high-boiling volatile compounds produced during refrigerated storage of haddock fillets were found by gas chromatography and mass spectroscopy to be phenethyl alcohol and phenol.
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340
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Chen TC, Day EJ. Gentian violet as a possible fungal inhibitor in poultry feed: plate assays on its antifungal activity. Poult Sci 1974; 53:1791-5. [PMID: 4213944 DOI: 10.3382/ps.0531791] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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341
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Chen TC, Castillo L, Korycka-Dahl M, DeLuca HF. Role of vitamin D metabolites in phosphate transport of rat intestine. J Nutr 1974; 104:1056-60. [PMID: 4854171 DOI: 10.1093/jn/104.8.1056] [Citation(s) in RCA: 149] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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342
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Kubena LF, Chen TC, Deaton JW, Reece FN. Factors influencing the quantity of abdominal fat in broilers. 3. Dietary energy levels. Poult Sci 1974; 53:974-8. [PMID: 4841683 DOI: 10.3382/ps.0530974] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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343
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Kubena LF, Deaton JW, Chen TC, Reece FN. Factors influencing the quality of abdominal fat in broilers. 1. Rearing temperature, sex, age or weight, and dietary choline chloride and inositol supplementation. Poult Sci 1974; 53:211-4. [PMID: 4833030 DOI: 10.3382/ps.0530211] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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344
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Lam HY, Schnoes HK, DeLuca HF, Chen TC. 24,25-Dihydroxyvitamin D3. Synthesis and biological activity. Biochemistry 1973; 12:4851-5. [PMID: 4761971 DOI: 10.1021/bi00748a007] [Citation(s) in RCA: 44] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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345
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Lin JK, Chen TC, Chiang HH, Tung TC. Studies on the effect of riboflavin tetrabutyrate on the atherosclerosis induced by cholesterol feeding in rabbits. I. Effect of riboflavin tetrabutyrate on serum and hepatic lipids. TAIWAN YI XUE HUI ZA ZHI. JOURNAL OF THE FORMOSAN MEDICAL ASSOCIATION 1973; 72:440-9. [PMID: 4520341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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346
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Chen TC, DeLuca HF. Receptors of 1,25-dikydroxycholecalciferol in rat intestine. J Biol Chem 1973; 248:4890-5. [PMID: 4717530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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347
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Chen TC, Deluca HF. Stimulation of (3H)uridine incorporation into nuclear RNA of rat kidney by vitamin D metabolites. Arch Biochem Biophys 1973; 156:321-7. [PMID: 4730476 DOI: 10.1016/0003-9861(73)90370-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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348
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Tanaka Y, Chen TC, Deluca HF. Dependence of 25-hydroxycholecalciferol-1-hydroxylase regulation on RNA and protein synthesis. Arch Biochem Biophys 1972; 152:291-8. [PMID: 5072703 DOI: 10.1016/0003-9861(72)90218-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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349
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Fuccillo DA, Sever JL, Moder FL, Chen TC, Catalano LW, Johnson LD. Cytomegalovirus antibody in patients with carcinoma of the uterine cervix. Obstet Gynecol 1971; 38:599-601. [PMID: 4329117 DOI: 10.1097/00006250-197110000-00016] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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350
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Horta-Barbosa L, Krebs H, Ley A, Chen TC, Gilkeson MR, Sever JL. Progressive increase in cerebrospinal fluid measles antibody levels in subacute sclerosing panencephalitis. Pediatrics 1971; 47:782-3. [PMID: 5089768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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