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Chang CT, Wu CS, Yang JT. Circular dichroic analysis of protein conformation: inclusion of the beta-turns. Anal Biochem 1978; 91:13-31. [PMID: 9762080 DOI: 10.1016/0003-2697(78)90812-6] [Citation(s) in RCA: 964] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The mean residue ellipticity, [theta], at any wavelength, lambda, of a protein in aqueous solution is expressed as [theta]lambda = fH[theta]H infinity(1-k/n) + f beta[theta]beta + ft[theta]t + fR[theta]R with two constraints: 1 > or = fj > or = 0 and sigma fj = 1. The subscripts H, beta, t, and R refer to the helix, beta-form, beta-turn, and unordered form. The fractions, fj's, of 15 proteins are based on X-ray crystallography, ft refers to the net beta-turn after cancelling those residues having dihedral angles of opposite sign. The [theta]H infinity of an infinite helix and its chain-length dependence factor, k, were computed from the myoglobin data (Chen et al., 1974, Biochemistry 13, 3350). The average number of residues per helical segment, n, for 15 proteins was about 10, which can be used for proteins of unknown structure. The reference spectra of other three structural elements are computed by a least-squares method. Once the reference spectra are chosen, the same equation above can be used to estimate the fractions of the secondary structure of a protein from its CD data points between 190 and 240 nm at 1-nm intervals. The computed helical content is usually good to excellent (concanavalin A is a notable exception). Inclusion of the beta-turn in the analysis improves the correlation for the estimates of the beta-form, but the computed beta t values are not significantly correlated with the X-ray results. Matrix formulation proves the equivalence of the least-squares method and the integral curve-fitting.
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964 |
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Davidson D, Barefield ES, Kattwinkel J, Dudell G, Damask M, Straube R, Rhines J, Chang CT. Inhaled nitric oxide for the early treatment of persistent pulmonary hypertension of the term newborn: a randomized, double-masked, placebo-controlled, dose-response, multicenter study. The I-NO/PPHN Study Group. Pediatrics 1998; 101:325-34. [PMID: 9480993 DOI: 10.1542/peds.101.3.325] [Citation(s) in RCA: 218] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVES To assess the dose-related effects of inhaled nitric oxide (I-NO) as a specific adjunct to early conventional therapy for term infants with persistent pulmonary hypertension (PPHN), with regard to neonatal outcome, oxygenation, and safety. METHODS Randomized, placebo-controlled, double-masked, dose-response, clinical trial at 25 tertiary centers from April 1994 to June 1996. The primary endpoint was the PPHN Major Sequelae Index ([MSI], including the incidence of death, extracorporeal membrane oxygenation (ECMO), neurologic injury, or bronchopulmonary dysplasia [BPD]). Patients required a fraction of inspired oxygen [FIO2] of 1.0, a mean airway pressure >/=10 cm H2O on a conventional ventilator, and echocardiographic evidence of PPHN. Exogenous surfactant, concomitant high-frequency ventilation, and lung hypoplasia were exclusion factors. Control (0 ppm) or nitric oxide (NO) (5, 20, or 80 ppm) treatments were administered until success or failure criteria were met. Due to slowing recruitment, the trial was stopped at N = 155 (320 planned). RESULTS The baseline oxygenation index (OI) was 24 +/- 9 at 25 +/- 17 hours old (mean +/- SD). Efficacy results were similar among NO doses. By 30 minutes (no ventilator changes) the PaO2 for only the NO groups increased significantly from 64 +/- 39 to 109 +/- 78 Torr (pooled) and systemic arterial pressure remained unchanged. The baseline adjusted time-weighted OI was also significantly reduced in the NO groups (-5 +/- 8) for the first 24 hours of treatment. The MSI rate was 59% for the control and 50% for the NO doses (P = .36). The ECMO rate was 34% for control and 22% for the NO doses (P = .12). Elevated methemoglobin (>7%) and nitrogen dioxide (NO2) (>3 ppm) were observed only in the 80 ppm NO group, otherwise no adverse events could be attributed to I-NO, including BPD. CONCLUSION For term infants with PPHN, early I-NO as the sole adjunct to conventional management produced an acute and sustained improvement in oxygenation for 24 hours without short-term side effects (5 and 20 ppm doses), and the suggestion that ECMO use may be reduced.
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218 |
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Garber A, Henry RR, Ratner R, Hale P, Chang CT, Bode B. Liraglutide, a once-daily human glucagon-like peptide 1 analogue, provides sustained improvements in glycaemic control and weight for 2 years as monotherapy compared with glimepiride in patients with type 2 diabetes. Diabetes Obes Metab 2011; 13:348-56. [PMID: 21205128 PMCID: PMC3084519 DOI: 10.1111/j.1463-1326.2010.01356.x] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
AIMS Most treatments for type 2 diabetes fail over time, necessitating combination therapy. We investigated the safety, tolerability and efficacy of liraglutide monotherapy compared with glimepiride monotherapy over 2 years. METHODS Participants were randomized to receive once-daily liraglutide 1.2 mg, liraglutide 1.8 mg or glimepiride 8 mg. Participants completing the 1-year randomized, double-blind, double-dummy period could continue open-label treatment for an additional year. Safety data were evaluated for the full population exposed to treatment, and efficacy data were evaluated for the full intention-to-treat (ITT) and 2-year completer populations. Outcome measures included change in glycosylated haemoglobin (HbA1c), fasting plasma glucose (FPG), body weight and frequency of nausea and hypoglycaemia. RESULTS For patients completing 2 years of therapy, HbA1c reductions were -0.6% with glimepiride versus -0.9% with liraglutide 1.2 mg (difference: -0.37, 95% CI: -0.71 to -0.02; p = 0.0376) and -1.1% with liraglutide 1.8 mg (difference: -0.55, 95% CI: -0.88 to -0.21; p = 0.0016). In the ITT population, HbA1c reductions were -0.3% with glimepiride versus -0.6% with liraglutide 1.2 mg (difference: -0.31, 95% CI: -0.54 to -0.08; p = 0.0076) and -0.9% with liraglutide 1.8 mg (difference: -0.60, 95% CI: -0.83 to -0.38; p < 0.0001). For both ITT and completer populations, liraglutide was more effective in reducing HbA1c, FPG and weight. Over 2 years, rates of minor hypoglycaemia [self-treated plasma glucose <3.1 mmol/l (<56 mg/dl)] were significantly lower with liraglutide 1.2 mg and 1.8 mg compared with glimepiride (p < 0.0001). CONCLUSION Liraglutide monotherapy for 2 years provides significant and sustained improvements in glycaemic control and body weight compared with glimepiride monotherapy, at a lower risk of hypoglycaemia.
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146 |
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Egbertson MS, Chang CT, Duggan ME, Gould RJ, Halczenko W, Hartman GD, Laswell WL, Lynch JJ, Lynch RJ, Manno PD. Non-peptide fibrinogen receptor antagonists. 2. Optimization of a tyrosine template as a mimic for Arg-Gly-Asp. J Med Chem 1994; 37:2537-51. [PMID: 8057299 DOI: 10.1021/jm00042a007] [Citation(s) in RCA: 145] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Inhibitors of platelet-fibrinogen binding offer an opportunity to interrupt the final, common pathway for platelet aggregation. Small molecule inhibitors of the platelet fibrinogen receptor GPIIb/IIIa were prepared and evaluated for their ability to prevent platelet aggregation. Compound 23m (L-700,462/MK-383) inhibited in vitro platelet aggregation with an IC50 of 9 nM and demonstrated a selectivity of > 24,000-fold between platelet and human umbilical vein endothelial cell fibrinogen receptors. Dose-dependent inhibition of ex vivo platelet aggregation induced by ADP was achieved with i.v. infusions of 0.1-10 micrograms/kg/min of 23m in anesthetized dogs, with 10 micrograms/kg/min completely inhibiting platelet aggregation during the entire 6 h infusion protocol. Platelet aggregatability returned rapidly after the termination of the 23m infusions. These features suggest that 23m may be useful in the treatment of arterial occlusive disorders.
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Comparative Study |
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145 |
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136 |
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Chen IS, Chang CT, Sheen WS, Teng CM, Tsai IL, Duh CY, Ko FN. Coumarins and antiplatelet aggregation constituents from Formosan Peucedanum japonicum. PHYTOCHEMISTRY 1996; 41:525-30. [PMID: 8821432 DOI: 10.1016/0031-9422(95)00625-7] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Four new khellactone esters, (-)-trans-3'-acetyl-4'-senecioylkhellactone, (+-)-cis-3'-acetyl-4'-tigloylkhellactone, (+-)-cis-4-tigloylkhellactone, (+)-trans-4'-tigloylkhellactone, together with 14 known coumarins, isoimperatorin, psoralen, bergapten, xanthotoxol, cnidilin, (-)-selinidin, (-)-deltoin, (+)-pteryxin, (+)-peucedanocoumarin III, xanthotoxin, imperatorin, (+)-marmesin, (+)-oxypeucedanin hydrate, (+)-peucedanol and three chromones, eugenin, (-)-hamaudol, (+)-visamminol, have been isolated from the root of Formosan Peucedanum japonicum. The structures of the new compounds were elucidated by spectral data. The identities of (+)-trans-3'-tigloyl-4'-acetylkhellactone, formerly reported as a new compound, and (+)-cis-3'-angeloyl-4'-acetyl-khellactone, with the known (+)-peucedanocoumarin III and (+)-pteryxin, respectively, are discussed. Among the isolates, seven compounds, eugenin, (-)-selinidin, (+)-pteryxin, imperatorin, bergapten, cnidilin and (+)-visamminol, show strong antiplatelet aggregation activity in vitro.
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Lipkin PH, Davidson D, Spivak L, Straube R, Rhines J, Chang CT. Neurodevelopmental and medical outcomes of persistent pulmonary hypertension in term newborns treated with nitric oxide. J Pediatr 2002; 140:306-10. [PMID: 11953727 DOI: 10.1067/mpd.2002.122730] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To determine the medical and neurodevelopmental outcome of children with moderately severe persistent pulmonary hypertension of the newborn (PPHN) treated with or without inhaled nitric oxide (I-NO). STUDY DESIGN Term infants with PPHN and a baseline oxygenation index of 24 +/- 9 at study entry were randomly assigned to early treatment with placebo or initial doses of I-NO (5, 20, and 80 ppm). Outcome was measured at approximately 1 year by frequency of hospitalization, growth, and neurodevelopmental and audiologic evaluation. RESULTS Of 155 children enrolled, 144 survived, and there was follow-up for 133. No significant differences between the placebo and the I-NO groups were seen in any long-term outcome. Rehospitalization occurred in 22%, and growth did not differ. The composite neurodevelopment and audiologic outcome showed impairment in 46% of the infants. There were major neurologic abnormalities in 13%, cognitive delays in 30%, and hearing loss in 19% of the infants. CONCLUSIONS Moderately severe PPHN at 24 hours after birth is associated with high rates of rehospitalization and disability at 1 year. Adverse outcomes were the same in I-NO and control groups.
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Clinical Trial |
23 |
88 |
8
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Chang CT, Fan MH, Kuo FC, Sung HY. Potent fibrinolytic enzyme from a mutant of Bacillus subtilis IMR-NK1. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2000; 48:3210-3216. [PMID: 10956093 DOI: 10.1021/jf000020k] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A mutant of Bacillus subtilis IMR-NK1, which is used for the production of domestic "natto" in Taiwan, produced high fibrinolytic enzyme activity by solid-state fermentation using wheat bran as medium. In addition, a strong fibrinolytic enzyme was purified from the cultivation media. The purified enzyme was almost homogeneous, as examined by SDS-PAGE and capillary electrophoresis. The enzyme had an optimal pH of 7.8, an optimal temperature of 55 degrees C, and a K(m) of 0.15% for fibrin hydrolysis. The molecular mass estimated by gel filtration was 31.5 kDa, and the isoelectric point estimated by isoelectric focusing electrophoresis was 8.3. The enzyme also showed activity for hydrolysis of fibrinogen, casein, and several synthetic substrates. Among the synthetic substrates, the most sensitive substrate was N-succinyl-Ala-Ala-Pro-Phe-pNA. PMSF and NBS almost completely inhibited the activity of the enzyme. These results indicate that the enzyme is a subtilisin-like serine protease, similar to nattokinase from Bacillus natto.
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25 |
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Barone G, Chang CT, Choc MG, Klein JB, Marsh CL, Meligeni JA, Min DI, Pescovitz MD, Pollak R, Pruett TL, Stinson JB, Thompson JS, Vasquez E, Waid T, Wombolt DG, Wong RL. The pharmacokinetics of a microemulsion formulation of cyclosporine in primary renal allograft recipients. The Neoral Study Group. Transplantation 1996; 61:875-80. [PMID: 8623152 DOI: 10.1097/00007890-199603270-00005] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This study was a randomized, double-blind, 12-week comparison of the pharmacokinetics, safety, and tolerability of two cyclosporine (CsA) formulations, cyclosporine emulsion capsules and oral solution for microemulsion and cyclosporine, in the postoperative management of renal transplant patients. Of the 101 patients, aged 18 to 65, who entered the study, 89 were evaluable for pharmacokinetics. Initial dosage was 10 mg/kg per day, administered twice daily in two equal doses. Dosages were adjusted to achieve target CsA concentrations. The pharmacokinetic (PK) parameters (dose-normalized) of greatest interest were maximum blood concentration (C(max)/dose), time to reach maximum concentration (t(max), area under the blood concentration-vs.-time curve (AUC/dose), and trough blood concentrations (Co h/dose). The relative CsA bioavailabilty was found to be significantly enhanced with cyclosporine emulsion compared with cyclosporine with a 16% to 31% increase in AUC and a 32% to 42% increase in C(max). Intrapatient variability of PK parameters was significantly lower with cyclosporine emulsion than with cyclosporine for AUC, C(oh), t(max), and C(max) in many instances. This indicates a more consistent, rapid, and more complete total absorption of CsA. Despite higher CsA C(max) levels and AUCs with cyclosporine emulsion, safety and tolerability (detailed in a parallel report) were comparable to those of cyclosporine. The PK advantages of cyclosporine emulsion over cyclosporine are either independent of food conditions or possibly reflective of more consistent absorption of CsA with cyclosporine emulsion. The findings suggest that de novo use of cyclosporine emulsion may simplify and improve management of organ transplant recipients and that the PK advantages of cyclosporine emulsion may translate into clinical benefits.
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Clinical Trial |
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10
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Tseng CJ, Pao CC, Tseng LH, Chang CT, Lai CH, Soong YK, Hsueh S, Jyu-Jen H. Lymphoepithelioma-like carcinoma of the uterine cervix: association with Epstein-Barr virus and human papillomavirus. Cancer 1997; 80:91-7. [PMID: 9210713 DOI: 10.1002/(sici)1097-0142(19970701)80:1<91::aid-cncr12>3.0.co;2-a] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND The presence of Epstein-Barr virus (EBV) has not been documented in previous reports of lymphoepithelioma-like carcinoma (LELC) of the uterine cervix by either polymerase chain reaction or in situ hybridization, and the histogenesis of the tumor remains unknown. Additionally, a relationship between human papillomavirus (HPV) and cervical LELC also has not been reported. METHODS In this article, the authors describe the clinical and histopathologic findings for 15 patients with cervical carcinoma that had a histologic pattern of LELC. The polymerase chain reaction detected the presence of EBV and HPV DNA sequences in cervical LELC. RESULTS All 15 tumors showed a typical syncytial growth pattern of undifferentiated cells with prominent lymphocytic infiltration. The detection rate of the EBV gene sequence in tissue samples from patients with LELC was more frequent than that in control patients with squamous cell carcinoma of the cervix (11 of 15 patients, 73.3%, vs. 4 of 15 patients, 26.7%; P = 0.01). However, the detection rate of HPV-16 and HPV-18 DNA was significantly lower in patients with LELC tumors than in patients with cervical squamous cell carcinoma (3 of 15 patients, 20.0%, vs. 12 of 15 patients, 80.0%; P = 0.001). After a median follow-up of 3.9 years (range, 1.8-5.3 years), the 15 patients showed no evidence of disease or metastasis after radical hysterectomy or radiotherapy. CONCLUSIONS The finding of EBV associations in cervical LELC supports the hypothesis that EBV may be involved in the pathogenesis of tumors that arise in the cervix. It is possible that cervical LELC may follow a different pathway in the pathogenesis of LELC in Asian women as compared with the more common forms of squamous cell carcinoma.
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Tseng CJ, Chang CT, Lai CH, Soong YK, Hong JH, Tang SG, Hsueh S. A randomized trial of concurrent chemoradiotherapy versus radiotherapy in advanced carcinoma of the uterine cervix. Gynecol Oncol 1997; 66:52-8. [PMID: 9234921 DOI: 10.1006/gyno.1997.4721] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The purpose of our study was to determine whether the chemoradiation is better than radiotherapy alone with respect to survival and treatment toxicity in patients with advanced carcinoma of the cervix. From October 1990 to April 1995, a total of 122 patients with advanced cervical carcinoma were included in this study and randomly assigned to either radiotherapy or concurrent chemotherapy and radiotherapy. The patients in the concurrent group received cisplatin, vincristine, and bleomycin every 3 weeks for a total of four courses, in combination with radiotherapy concurrently. Sixty patients were randomized to the concurrent chemoradiotherapy, and 62 were randomized to the radiotherapy alone. A tumor response was observed in 88.3% of the patients in concurrent group and in 74.2% of the patients in radiotherapy group (P = 0.04). After a median follow-up of 46.8 months, the overall disease-free survival and actuarial survival rate at 3 years were 51.7 and 61.7% in the concurrent group, and 53.2 and 64.5% in the radiotherapy group, respectively. Treatment-related toxicity appears to be higher with the combination of radiotherapy and chemotherapy compared with radiotherapy alone (36.7% versus 17.7%, P = 0.02). However, analysis by Kaplan-Meier method showed that the actuarial survival was not statistically different between the chemoradiotherapy and radiotherapy groups (mean survival time: 38.1 months versus 41.5 months, P = 0.27). In conclusion, this study showed that concurrent multiagent chemoradiotherapy did not prove to be a superior definitive therapy over radiotherapy alone for patients with advanced cervical carcinoma.
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Clinical Trial |
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Davidson D, Barefield ES, Kattwinkel J, Dudell G, Damask M, Straube R, Rhines J, Chang CT. Safety of withdrawing inhaled nitric oxide therapy in persistent pulmonary hypertension of the newborn. Pediatrics 1999; 104:231-6. [PMID: 10429000 DOI: 10.1542/peds.104.2.231] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Because of case reports describing hypoxemia on withdrawal of inhaled nitric oxide (I-NO), we prospectively examined this safety issue in newborns with persistent pulmonary hypertension who were classified as treatment successes or failures during a course of I-NO therapy. METHODS Randomized, placebo-controlled, double-masked, dose-response clinical trial at 25 tertiary centers from April 1994 to June 1996. Change in oxygenation and outcome (death and/or extracorporeal membrane oxygenation) during or immediately after withdrawing I-NO were the principal endpoints. Patients (n = 155) were term infants, <3 days old at study entry with echocardiographic evidence of persistent pulmonary hypertension of the newborn. Exclusion criteria included previous surfactant treatment, high-frequency ventilation, or lung hypoplasia. Withdrawal from treatment gas (0, 5, 20, or 80 ppm) started once treatment success or failure criteria were met. Withdrawal of treatment gas occurred at 20% decrements at <4 hours between steps. RESULTS The patient profile was similar for placebo and I-NO groups. Treatment started at an oxygenation index (OI) of 25 +/- 10 (mean +/- SD) at 26 +/- 18 hours after birth. For infants classified as treatment successes (mean duration of therapy = 88 hours, OI <10), decreases in the arterial partial pressure of oxygen (PaO(2)) were observed only at the final step of withdrawal. On cessation from 1, 4, and 16 ppm, patients receiving I-NO demonstrated a dose-related reduction in PaO(2) (-11 +/- 23, -28 +/- 24, and -50 +/- 48 mm Hg, respectively). For infants classified as treatment failures (mean duration of therapy = 10 hours), no change in OI occurred for the placebo group (-13 +/- 36%, OI of 31 +/- 11 after the withdrawal process); however a 42 +/- 101% increase in OI to 46 +/- 21 occurred for the pooled nitric oxide doses. One death was possibly related to withdrawal of I-NO. CONCLUSION For infants classified as treatment successes, a dose response between the I-NO dose and decrease in PaO(2) after discontinuing I-NO was found. A reduction in I-NO to 1 ppm before discontinuation of the drug seems to minimize the decrease in PaO(2) seen. For infants failing treatment, discontinuation of I-NO could pose a life-threatening reduction in oxygenation should extracorporeal membrane oxygenation not be readily available or I-NO cannot be continued on transport.
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Clinical Trial |
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68 |
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Vehaskari VM, Chang CT, Stevens JK, Robson AM. The effects of polycations on vascular permeability in the rat. A proposed role for charge sites. J Clin Invest 1984; 73:1053-61. [PMID: 6200500 PMCID: PMC425118 DOI: 10.1172/jci111290] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
This study investigated whether charge sites in the walls of the microvasculature may play a role in maintaining the impermeability of the nonrenal capillaries to albumin. All experiments were performed in nephrectomized rats, studied in the awake state. The intravenous injection of protamine sulfate (4 mg/100 g body wt dissolved in 0.9% saline) was followed by a mean increase of 29.1% in hematocrit and a decrease of 28.4% in plasma albumin concentration over a 10-min period, indicating a significant 50-60% loss of albumin from the vascular space; a finding confirmed by studies using exogenous 125I-labeled albumin. Changes persisted for the remaining 80 min of observation, and could be reproduced by the injection of two other polycations, hexadimethrine and poly-l-lysine. These effects were not prevented by the antihistamine diphenhydramine hydrochloride. In contrast to 125I-labeled albumin, 14C-labeled neutral dextran of comparable size was not confined to the vascular space; its apparent volume of distribution progressively increased during the 90 min of observation. Intravenous injection of protamine sulfate was followed by a significantly smaller loss of 14C-dextran (36.5%) than albumin (59.1%) from the vascular space (P less than 0.01). Protamine sulfate could not be demonstrated to result in any changes in the physicochemical characteristics of albumin. These observations suggest that the negative charge sites present in nonglomerular capillary walls have functions similar to equivalent sites present in the glomerular capillaries. Thus, charge sites could contribute to the low permeability of the microvasculature to negatively charged macromolecules such as albumin. This may be an important mechanism for retaining albumin in the vascular space and preventing edema formation in health.
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research-article |
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63 |
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Duggan ME, Naylor-Olsen AM, Perkins JJ, Anderson PS, Chang CT, Cook JJ, Gould RJ, Ihle NC, Hartman GD, Lynch JJ. Non-peptide fibrinogen receptor antagonists. 7. Design and synthesis of a potent, orally active fibrinogen receptor antagonist. J Med Chem 1995; 38:3332-41. [PMID: 7650686 DOI: 10.1021/jm00017a017] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The design, synthesis, and pharmacological evaluation of L-734,217, a potent, low-molecular weight, orally active fibrinogen receptor antagonist, is reported. A strategy for producing low-molecular weight inhibitors from the peptide c-[(Ac)CRGDC] A, previously reported from these laboratories, is outlined. This strategy combines a retrodesign analysis of the conformationally defined cyclic peptide A with stereochemical information present in the arginine-glycine-aspartic acid (RGD) tripeptide sequence, culminating with the discovery of L-734,217. L-734,217 inhibited the aggregation of human, dog, and chimpanzee platelets at concentrations below 100 nM and was found to be > 15000-fold less effective at inhibiting the attachment of human umbilical vein endothelial cells to fibrinogen, fibronectin, and vitronectin than it was at inhibiting the aggregation of platelets. L-734,217 showed significant ex vivo antiplatelet activity following oral administration in dogs and chimpanzees at doses of 1.0 and 2.0 mg/kg, respectively, and has been selected as a clinical candidate for development as an antithrombotic agent.
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Chang CT, Hain TC, Hutton JR, Wetmur JG. Effects of microscopic and macroscopic viscosity on the rate of renaturation of DNA. Biopolymers 1974; 13:1847-58. [PMID: 4413154 DOI: 10.1002/bip.1974.360130915] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Lin CL, Yang CW, Chiang CC, Chang CT, Huang CC. Long-term on-line hemodiafiltration reduces predialysis beta-2-microglobulin levels in chronic hemodialysis patients. Blood Purif 2001; 19:301-7. [PMID: 11244190 DOI: 10.1159/000046958] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Hemodiafiltration (HDF) is effective in delaying the surgical need for carpal tunnel syndrome in chronic hemodialysis patients, however, predialysis beta(2)-microglobulin levels were not reduced in most short-term studies. The aim of this study was to assess the effect of long-term and differing frequencies of on-line HDF on serum beta(2)-microglobulin levels in comparison to high-flux hemodialysis (HD). METHODS One hundred and twelve patients in the Chang Gung Memorial Hospital Dialysis Unit were divided into three groups to receive different frequencies of on-line HDF alternating with high-flux HD. Group 1 was treated once with HDF and twice with high-flux HD per week (n = 21). Group 2 was treated twice with HDF and once with high-flux HD per week (n = 33). Group 3 was treated with HDF three times per week (n = 58). Analysis was performed to compare the serum beta(2)-microglobulin levels in these groups and to high-flux HD. RESULTS After receiving HDF for a mean of 7.9 months, group 3 patients had a reduced predialysis beta(2)-microglobulin level (22.2 +/-5.3 vs. 34.8 +/-6.3 mg/l, p < 0.001), postdialysis beta(2)-microglobulin level (6.3 +/- 2.0 vs. 13.8 +/- 6.8 mg/l, p < 0.001) and an increased beta(2)-microglobulin reduction rate (76.1 +/- 5.6 vs. 61.1 +/- 13.3%, p = 0.03) when compared to high-flux HD. A significant improvement in URR (p = 0.0004), Kt/V (p = 0.0002) and TAC urea levels (p = 0.006) but not nPCR (p = 0.122) was found after patients had been treated with on-line HDF. The beta(2)-microglobulin reduction rate was positively correlated with the overall volume of the replacement solution per session (p < 0.0001). Patients in group 3 had lower predialysis beta(2)-microglobulin levels than those in group 1 and group 2 (22.2 +/- 5.3 vs. 25.2 +/- 7.2 vs. 26.0 +/- 4.2 mg/l, p = 0.02). Furthermore, an inverse correlation was found between the predialysis beta(2)-microglobulin level and the duration of HDF, if patients were treated for more than 12 months (p = 0.031). CONCLUSION On-line HDF has an increased dialysis efficiency compared to high-flux dialysis. Long-term HDF further reduced predialysis beta(2)-microglobulin levels, thus, it may provide an improved modality for renal replacement therapy.
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Clinical Trial |
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46 |
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Jen JF, Chang CT, Yang TC. On-line microdialysis-high-performance liquid chromatographic determination of aniline and 2-chloroaniline in polymer industrial wastewater. J Chromatogr A 2001; 930:119-25. [PMID: 11681569 DOI: 10.1016/s0021-9673(01)01185-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Determination of aniline and 2-chloroaniline in polymer industrial wastewater was examined using high-performance liquid chromatography with on-line microdialysis. After dilution, aniline and 2-chloroaniline in the sample were diffused through a cellular dialysis membrane into the perfusion stream under controlled conditions. Conditions for obtaining optimum dialysis efficiency such as flow-rate and polarity modifier in the perfusion stream, pH and added salt in the sample solution, as well as chromatographic conditions were investigated. The results indicate that the dialysis achieved at a sample matrix pH value of 9.5 with 0.1 M NaCl addition, and the perfusate at 10-microl/min flow-rate offered optimum dialysis efficiency. The aniline and 2-chloroaniline were well separated in an acceptable time on a reversed-phase C18 column eluted with 40% aqueous methanol solution at pH 7.0 and 1.0 ml/min flow-rate. The proposed method provided a very simple procedure to determine aniline and 2-chloroaniline in wastewater. Application was illustrated by the analysis of aniline and 2-chloroaniline in wastewater released from a polymer factory.
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Chang CT, Wu CY, Muirhead AR, Lombardi JR. The dipole moment in the lowest singlet pi formed from pi state of indole determined by the optical Stark effect. Photochem Photobiol 1974; 19:347-51. [PMID: 4841597 DOI: 10.1111/j.1751-1097.1974.tb06522.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Lin CL, Huang CC, Chang CT, Wu MS, Hung CC, Chien CC, Yang CW. Clinical improvement by increased frequency of on-line hemodialfiltration. Ren Fail 2001; 23:193-206. [PMID: 11417951 DOI: 10.1081/jdi-100103491] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND/AIMS In spite of the better efficiency of on-line hemodiafiltration (HDF) compared with conventional hemodialysis (HD), it is relatively expensive. The aim of this study was to assess the advantages in the biochemical, hemodynamic and clinical effects in uremic patients treated with on-line HDF and with different frequencies of combination high-flux HD. METHODS One hundred eleven patients were divided into four groups receiving different frequencies of on-line HDF (thrice, twice, once per week) and high-flux HD. RESULTS Hemodynamic parameters including maximum drop of systolic blood pressure, episodes of symptomatic hypotension and mean saline infusion volumes during dialysis were reduced when frequencies of on-line HDF were increased. Significant improvements in urea kinetic were observed when frequencies of on-line HDF were increased. On-line HDF significantly reduced the amount of erythropoietin needed and improved intra- and inter-dialysis symptoms, physical well-being, menstruation and skin pigmentation when frequency of HDF is increased to three time per week. CONCLUSION On-line HDF offers a better cardiovascular stability and clinical improvement. Thrice weekly on-line HDF offers a significant benefit when compared with lower frequencies of HDF per week and high-flux HD.
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Clinical Trial |
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Kim DS, Ashendel CL, Zhou Q, Chang CT, Lee ES, Chang CJ. Novel protein kinase C inhibitors: alpha-terthiophene derivatives. Bioorg Med Chem Lett 1998; 8:2695-8. [PMID: 9873605 DOI: 10.1016/s0960-894x(98)00468-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of alpha-terthiophene derivatives were prepared and their protein kinase C inhibitory activity were evaluated. The aldehyde derivatives were most potent inhibitors (IC50 < 1 microM). alpha-Terthiophene monoaldehyde was inactive in the inhibitions of protein kinase A, mitogen activated protein kinase and protein tyrosine kinase.
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Liang HL, Pan HB, Lee YH, Huang JS, Wu TD, Chang CT, Liang HL, Yang TL, Yang CF. Small functional adrenal cortical adenoma: treatment with CT-guided percutaneous acetic acid injection--report of three cases. Radiology 1999; 213:612-5. [PMID: 10551251 DOI: 10.1148/radiology.213.2.r99nv10612] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Two patients with Conn syndrome and one patient with Cushing syndrome underwent computed tomography (CT)-guided tumor ablation with a total of 5-11 mL of 50% acetic acid injected into their adrenal nodule (1.3-3.3 cm in diameter). No major complications were encountered during or after the procedure. All patients were symptom free with normal laboratory test results for at least 1-year follow-up. CT images showed complete cystic change with tumor size regression. Our preliminary results suggest that percutaneous acetic acid injection is a safe and effective alternative for treatment of small functional adrenal cortical adenoma.
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Elder CA, Moore M, Chang CT, Jin J, Charnick S, Nedelman J, Cohen A, Guzzo C, Lowe N, Simpson K. Efficacy and pharmacokinetics of two formulations of cyclosporine A in patients with psoriasis. J Clin Pharmacol 1995; 35:865-75. [PMID: 8786246 DOI: 10.1002/j.1552-4604.1995.tb04131.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The efficacy and pharmacokinetic profiles of two oral formulations of cyclosporine A (Sandimmune and Neoral; Sandoz Pharmaceuticals, East Hanover, NJ) were evaluated in 37 patients with moderate to severe plaque psoriasis in a randomized, double-blind, modified, crossover study. Cyclosporine A (150 mg twice daily), administered in either formulation, reduced the severity of plaque lesions: 94% of all patients reported at least moderate improvement and 70% reported complete clearing. Approximately 2 weeks of therapy were required for drug exposure to stabilize on either formulation. Cyclosporine A exposure from Neoral was significantly greater relative to that from Sandimmune across all study weeks. At the eighth week (before crossover), AUC and Cmax values for Neoral and Sandimmune were 5618 +/- 1705 versus 3202 +/- 596 ng.h/mL and 1283 +/- 337 versus 623 +/- 173 ng/mL, respectively. In crossover analysis at steady state, the relative oral bioavailability of cyclosporine from the Neoral formulation was 54% greater than that from Sandimmune. Some pharmacokinetic parameters showed less variability both between and within groups of patients taking Neoral versus Sandimmune. Both formulations were well tolerated, in that most adverse events were of mild severity.
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Clinical Trial |
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Chang CJ, Floss HG, Soong P, Chang CT. Identity of the antitumor antibiotic litmomycin with granaticin A. J Antibiot (Tokyo) 1975; 28:156. [PMID: 1112767 DOI: 10.7164/antibiotics.28.156] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Abstract
Delayed hypersensitivity can be induced in C57BL/6J mice by two subcutaneous injections of Merthiolate-killed Blastomyces dermatitidis yeast cells in Freund incomplete adjuvant. Development of delayed hypersensitivity peaked at the day 18 post-primary antigen-emulsion injection, as determined by footpad sensitivity tests. Mice rendered hypersensitive to B. dermatitidis were protected from the lethal effect of a blastomyces infection. The protection effects were shown both in mortality tests and in data from organ cultures as expressed by indices of resistance. Data from this study show that there is a close parallel relationship between host resistance and the prevailing level of delayed hypersensitivity.
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research-article |
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Abstract
STATEMENT OF PROBLEM Concerns of laser welding for titanium dental prostheses are the limited depth of laser beam penetration and extensive surface damage. PURPOSE This study used numerical heat transfer simulation to explain this behavior and offers an alternate multiple-pulsed method. MATERIAL AND METHODS A one-dimensional finite difference analysis was used to simulate heat transfer in pure titanium and gold during laser welding with a custom-constructed software program. RESULTS The thermal gradient profiles revealed the problem to be inherent in titanium's low thermal conductivity; gold did not have this problem. Time-elapsed multiple pulses on titanium relieved this problem by giving the energy time to diffuse into the depth of the material. CONCLUSIONS With single-pulse laser irradiation on titanium, an increase in power could not greatly increase melting depth. The excess energy only vaporized the material surface.
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Comparative Study |
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