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Hwang SJ, Ballantyne CM, Sharrett AR, Smith LC, Davis CE, Gotto AM, Boerwinkle E. Circulating adhesion molecules VCAM-1, ICAM-1, and E-selectin in carotid atherosclerosis and incident coronary heart disease cases: the Atherosclerosis Risk In Communities (ARIC) study. Circulation 1997; 96:4219-25. [PMID: 9416885 DOI: 10.1161/01.cir.96.12.4219] [Citation(s) in RCA: 909] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Recruitment of circulating leukocytes at sites of atherosclerosis is mediated through a family of adhesion molecules. The function of circulating forms of these adhesion molecules remains unknown, but their levels may serve as molecular markers of subclinical coronary heart disease (CHD). METHODS AND RESULTS To determine the ability of circulating vascular cell adhesion molecule-1 (VCAM-1), endothelial-leukocyte adhesion molecule-1 (E-selectin), and intercellular adhesion molecule-1 (ICAM-1) to serve as molecular markers of atherosclerosis and predictors of incident CHD, we studied 204 patients with incident CHD, 272 patients with carotid artery atherosclerosis (CAA), and 316 control subjects from the large, biracial Atherosclerosis Risk In Communities (ARIC) study. Levels of VCAM-1 were not significantly different among the patients with incident CHD, those with CAA, and control subjects. Higher levels of E-selectin and ICAM-1 were observed for the patients with CHD (means [ng/mL]: E-selectin, 38.4; ICAM-1, 288.7) and those with CAA (E-selectin, 41.5; ICAM-1, 283.6) compared with the control subjects (E-selectin, 32.8; ICAM-1, 244.2), but the distributions were not notably different between the patients with CHD and CAA. Results of logistic regression analyses indicated that the relationship of ICAM-1 and E-selectin with CHD and CAA was independent of other known CHD risk factors and was most pronounced in the highest quartile. The odds of CHD and CAA were 5.53 (95% CI, 2.51-12.21) and 2.64 (95% CI, 1.40-5.01), respectively, for those with levels of ICAM-1 in the highest quartile compared with those in the lowest quartile. Odds of CAA were 2.03 (95% CI, 1.14-3.62) for those with levels of E-selectin in the highest quartile compared with those in the lowest quartile. CONCLUSIONS These data indicate that plasma levels of ICAM-1 and E-selectin may serve as molecular markers for atherosclerosis and the development of CHD.
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Ko JA, Park HJ, Hwang SJ, Park JB, Lee JS. Preparation and characterization of chitosan microparticles intended for controlled drug delivery. Int J Pharm 2002; 249:165-74. [PMID: 12433445 DOI: 10.1016/s0378-5173(02)00487-8] [Citation(s) in RCA: 293] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Chitosan microparticles were prepared with tripolyphosphate (TPP) by ionic crosslinking. The particle sizes of TPP-chitosan microparticles were in range from 500 to 710 microm and encapsulation efficiencies of drug were more than 90%. The morphologies of TPP-chitosan microparticles were examined with scanning electron microscopy. As pH of TPP solution decreased and molecular weight (MW) of chitosan increased, microparticles had more spherical shape and smooth surface. Release behaviors of felodipine as a model drug were affected by various preparation processes. Chitosan microparticles prepared with lower pH or higher concentration of TPP solution resulted in slower felodipine release from microparticles. With decreasing MW and concentration of chitosan solution, release behavior was increased. The release of drug from TPP-chitosan microparticles decreased when cross-linking time increased. These results indicate that TPP-chitosan microparticles may become a potential delivery system to control the release of drug.
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293 |
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Gonzalez H, Hwang SJ, Davis ME. New class of polymers for the delivery of macromolecular therapeutics. Bioconjug Chem 1999; 10:1068-74. [PMID: 10563777 DOI: 10.1021/bc990072j] [Citation(s) in RCA: 269] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cationic polymers show promise for the in vitro and in vivo delivery of macromolecular therapeutics. Known cationic polymers, e.g., poly(L)lysine (PLL) and polyethylenimine (PEI), have been employed in native and modified forms for the delivery of plasmid DNA (pDNA) and reveal varying levels of toxicity. Here, we report the preparation of a new class of cationic polymers that are specifically designed to deliver macromolecular therapeutics. Linear, cationic, beta-cyclodextrin (beta-CD)-containing polymers (CD-polymers) are synthesized by copolymerizing difunctionalized beta-CD monomers (AA) with other difunctionalized comonomers (BB) such that an AABBAABB product is formed. The beta-CD polymers are able to bind approximately 5 kbp pDNA above polymer to DNA (+/-) charge ratios of 1.5, compact the bound pDNA into particles of approximately 100-150 nm in size at charge ratios above 5+/-, and transfect cultured cells at charge ratios above 10+/-. In vitro transfections with the new beta-CD-polymers are comparable to the best results obtained in our hands with PEI and Lipofectamine. Some cell line-dependent toxicities are observed for serum-free transfections; however, no toxicity is revealed at charge ratios as high as 70+/- in transfections conducted in 10% serum. Single IV and IP doses as high as 200 mg/kg in mice showed no mortalities.
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Huang H, Kim HJ, Chang EJ, Lee ZH, Hwang SJ, Kim HM, Lee Y, Kim HH. IL-17 stimulates the proliferation and differentiation of human mesenchymal stem cells: implications for bone remodeling. Cell Death Differ 2009; 16:1332-43. [PMID: 19543237 DOI: 10.1038/cdd.2009.74] [Citation(s) in RCA: 186] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Interleukin-17 (IL-17) is a cytokine secreted primarily by T(H)-17 cells. Although IL-17 is primarily associated with the induction of tissue inflammation, the other biological roles of IL-17, including non-immune functions, have yet to be thoroughly explored. Here, we report that T-cell-produced IL-17 can induce proliferation of human bone marrow-derived mesenchymal stem cells (hMSCs) in a manner dependent on the generation of reactive oxygen species (ROS). Rac1 GTPase and NADPH oxidase 1 (Nox1) are activated by IL-17 to produce ROS, which in turn stimulates hMSC proliferation. The activation of the MEK-ERK pathway is also crucial for IL-17-dependent hMSC proliferation. TRAF6 and Act1 are required to activate Nox 1 and to phosphorylate MEK on IL-17 stimulation. Interestingly, IL-17 not only accelerates the proliferation of hMSCs, but also induces their migration, motility, and osteoblastic differentiation. Furthermore, IL-17 induces the expression of M-CSF and receptor activator of NF-kappaB ligand (RANKL) on hMSCs, thereby supporting osteoclastogenesis both in vivo and in vitro. On the basis of these results, we suggest that IL-17 can function as a signal to induce extensive bone turnover by regulating hMSC recruitment, proliferation, motility, and differentiation.
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Research Support, Non-U.S. Gov't |
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186 |
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Hwang SJ, Bellocq NC, Davis ME. Effects of structure of beta-cyclodextrin-containing polymers on gene delivery. Bioconjug Chem 2001; 12:280-90. [PMID: 11312690 DOI: 10.1021/bc0001084] [Citation(s) in RCA: 185] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Linear cationic beta-cyclodextrin-based polymers (betaCDPs) are capable of forming polyplexes with nucleic acids and transfecting cultured cells. The betaCDPs are synthesized by the condensation of a diamino-cyclodextrin monomer A with a diimidate comonomer B. In this paper, the effects of polymer structure on polyplex formation, in vitro transfection efficiency and toxicity are elucidated. By comparison of the betaCDPs to polyamidines lacking cyclodextrins, the inclusion of a cyclodextrin moiety in the comonomer A units reduces the IC50s of the polymer by up to 3 orders of magnitude. The spacing between the cationic amidine groups is also important. Different polymers with 4, 5, 6, 7, 8, and 10 methylene units (betaCDP4, 5, 6, 7, 8, and 10) in the comonomer B molecule are synthesized. Transfection efficiency is dependent on comonomer B length with up to 20-fold difference between polymers. Optimum transfection is achieved with the betaCDP6 polymer. In vitro toxicity varied by 1 order of magnitude and the lowest toxicity is observed with betaCDP8. The LD40 of the betaCDP6 to mice is 200 mg/kg, making this polymer a promising agent for in vivo gene delivery applications.
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Choi BY, Park HJ, Hwang SJ, Park JB. Preparation of alginate beads for floating drug delivery system: effects of CO(2) gas-forming agents. Int J Pharm 2002; 239:81-91. [PMID: 12052693 DOI: 10.1016/s0378-5173(02)00054-6] [Citation(s) in RCA: 179] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Floating beads were prepared from a sodium alginate solution containing CaCO(3) or NaHCO(3) as gas-forming agents. The solution was dropped to 1% CaCl(2) solution containing 10% acetic acid for CO(2) gas and gel formation. The effects of gas-forming agents on bead size and floating properties were investigated. As gas-forming agents increased, the size and floating properties increased. Bead porosity and volume average pore size, as well as the surface and cross-sectional morphology of the beads were examined with Mercury porosimetry and Scanning Electron Microscopy. NaHCO(3) significantly increased porosity and pore diameter than CaCO(3). Incorporation of CaCO(3) into alginate solution resulted in smoother beads than those produced with NaHCO(3). Gel strength analysis indicated that bead strength decreased with increasing gas-forming agent from 9 to 4 N. Beads incorporating CaCO(3) exhibited significantly increased gel strength over control and NaHCO(3)-containing samples. Release characteristics of riboflavin as a model drug were studied in vitro. Release rate of riboflavin increased proportionally with addition of NaHCO(3). However, increasing weight ratios of CaCO(3) did not appreciably accelerate drug release. The results of these studies indicate that CaCO(3) is superior to NaHCO(3) as a gas forming agent in alginate bead preparations. The enhanced buoyancy and sustained release properties of CaCO(3)-containing beads make them an excellent candidate for floating drug dosage systems (FDDS).
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Comparative Study |
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179 |
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Hwang SJ, Beaty TH, Panny SR, Street NA, Joseph JM, Gordon S, McIntosh I, Francomano CA. Association study of transforming growth factor alpha (TGF alpha) TaqI polymorphism and oral clefts: indication of gene-environment interaction in a population-based sample of infants with birth defects. Am J Epidemiol 1995; 141:629-36. [PMID: 7702037 DOI: 10.1093/oxfordjournals.aje.a117478] [Citation(s) in RCA: 162] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In this study of infants with isolated birth defects, 69 cleft palate only cases, 114 cleft lip with or without cleft palate cases, and 284 controls with noncleft birth defects (all born in Maryland between 1984 and 1992) were examined to test for associations among maternal exposures, genetic markers, and oral clefts. A significantly higher frequency of positive family history of birth defects among both groups of oral cleft cases compared with controls was seen in these data. While there was a modest increase in the less common C2 allele at the TaqI site in the transforming growth factor alpha (TGF alpha) locus among cleft palate only infants compared with the birth defect controls, the association appeared to reflect an underlying interaction between maternal smoking and infant genotype. This apparent gene-environment interaction was also found among those reporting no family history of any birth defect. Infants carrying the rarer C2 allele who were exposed to maternal smoking of 10 or fewer cigarettes per day showed a 6.16-fold increase in risk for cleft palate only (95% confidence interval 1.09-34.7), while similar infants whose mothers smoked more than 10 cigarettes per day showed an 8.69-fold higher risk (95% confidence interval 1.57-47.8). However, the dose-response relation was not significant.
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Hwang SJ, Luo JC, Chu CW, Lai CR, Lu CL, Tsay SH, Wu JC, Chang FY, Lee SD. Hepatic steatosis in chronic hepatitis C virus infection: prevalence and clinical correlation. J Gastroenterol Hepatol 2001; 16:190-5. [PMID: 11207900 DOI: 10.1046/j.1440-1746.2001.02407.x] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND AIMS Hepatic steatosis is a histological characteristic in patients with chronic hepatitis C virus (HCV) infection. The aim of this study was to evaluate the prevalence of hepatic steatosis in Chinese patients with chronic hepatitis C, and to look for possible correlation with various histopathological changes and to look for possible correlation with various clinical and pathologic variables. METHODS One hundred and six patients were enrolled, and patients with alcoholism or diabetes mellitus were excluded. Clinical, biochemical and virologic data, including HCV genotype and serum HCV-RNA titer and histological findings, were compared between patients with and without hepatic steatosis. RESULTS Fifty-five (52%) of the 106 patients with chronic hepatitis C had hepatic steatosis. Patients with hepatic steatosis had significantly higher mean serum levels of triglyceride and gamma-glutamyl transpeptidase, higher body mass index, and a higher incidence of obesity compared with patients without hepatic steatosis. No significant differences in serum HCV-RNA titer and HCV genotype or the response to interferon therapy were noted between the two groups. Histological analysis showed patients with hepatic steatosis had a significantly higher mean fibrotic score than patients without hepatic steatosis (1.9 +/- 1.2 vs 1.3 +/- 1.0; P = 0.016). There were no significant differences in the severity of necroinflammation, the presence of lymphoid aggregation/follicle or bile duct damage between the two groups. Multivariate logistic regression analysis showed that independent predictors associated with hepatic steatosis were obesity or a histology fibrotic score of > or = 2. CONCLUSION It was found that 52% of Chinese patients with chronic hepatitis C had hepatic steatosis. Patients with hepatic steatosis were more frequently obese and had more severe hepatic fibrosis.
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Comparative Study |
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123 |
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Hsieh WJ, Lin HC, Hwang SJ, Hou MC, Lee FY, Chang FY, Lee SD. The effect of ciprofloxacin in the prevention of bacterial infection in patients with cirrhosis after upper gastrointestinal bleeding. Am J Gastroenterol 1998; 93:962-6. [PMID: 9647029 DOI: 10.1111/j.1572-0241.1998.00288.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Cirrhotic patients with upper gastrointestinal bleeding are prone to bacterial infection. The aim of this study was to investigate the efficacy of prophylactic intestinal decontamination with oral ciprofloxacin for the prevention of bacterial infections in cirrhotic patients with upper gastrointestinal bleeding. METHODS A total of 120 cirrhotic patients with acute upper gastrointestinal bleeding were enrolled. Sixty patients received ciprofloxacin 500 mg twice daily given orally or through nasogastric tube immediately after upper gastrointestinal endoscopic examination; drug administration continued for 7 days. The remaining 60 patients, who received placebo, served as controls. RESULTS The incidence of proven bacterial infection in the ciprofloxacin-treated group was significantly lower than that of placebo group (10% vs 45%, p < 0.001). The incidences of bacteremia, spontaneous bacterial peritonitis, and urinary tract infection in the ciprofloxacin-treated group were significantly lower than those in the placebo group (0% vs 23%, 3.3% vs 13%, and 5% vs 18%, respectively; p < 0.05, respectively). Multivariate logistic regression analysis showed that a lack of prophylactic treatment with ciprofloxacin and severity of cirrhosis were the independent significant predictors for cirrhotic patients with acute gastrointestinal bleeding with infection. CONCLUSIONS Prophylactic intestinal decontamination with oral ciprofloxacin is effective in the prevention of bacterial infections in patients with cirrhosis who were suffering from acute upper gastrointestinal hemorrhage.
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Clinical Trial |
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90 |
10
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Park JS, Sohn CI, Hwang SJ, Choi HS, Park JH, Kim HJ, Park DI, Cho YK, Jeon WK, Kim BI. Quality and effect of single dose versus split dose of polyethylene glycol bowel preparation for early-morning colonoscopy. Endoscopy 2007; 39:616-9. [PMID: 17611916 DOI: 10.1055/s-2007-966434] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND STUDY AIMS The conventional procedure of ingestion of an entire dose of polyethylene glycol solution on the day before early-morning colonoscopy may result in poor bowel preparation. The aim of this study was to evaluate the efficacy and effect of a split-dose ingestion of polyethylene glycol for early-morning colonoscopy. METHODS A total of 303 age- and sex-matched consecutive individuals presenting for medical check-ups were randomly assigned to receive either 4 L of polyethylene glycol solution with a soft diet on the day before colonoscopy (n = 152; group A), or 3 L of polyethylene glycol solution with a soft diet on the preceding day and then 1 L of the solution on the day of colonoscopy (n = 151; group B). The quality of bowel preparation was evaluated using the Ottawa scale, and the time to cecal intubation and the technical difficulty during the procedure were also recorded. RESULTS There was no difference in compliance between group A (single-dose) and group B (split-dose). The quality of bowel preparation was better in group B compared with group A. When the participants were categorized according to compliance (good compliance, 116 in group A, 119 in group B; poor compliance, 36 in group A, 32 in group B), the quality of the bowel preparation had a higher score in the good compliance compared with the poor compliance group, and in group B this difference was usually significant. CONCLUSIONS Split-dose bowel preparation with polyethylene glycol solution provided a better quality preparation than the conventional method for patients undergoing early-morning colonoscopy.
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Randomized Controlled Trial |
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86 |
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Hwang SJ, Haers PE, Zimmermann A, Oechslin C, Seifert B, Sailer HF. Surgical risk factors for condylar resorption after orthognathic surgery. ORAL SURGERY, ORAL MEDICINE, ORAL PATHOLOGY, ORAL RADIOLOGY, AND ENDODONTICS 2000; 89:542-52. [PMID: 10807709 DOI: 10.1067/moe.2000.105239] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The purpose of this study was to look for surgical risk factors for condylar resorption after orthognathic surgery. STUDY DESIGN Seventeen patients of a group of 452 patients who had undergone orthognathic surgery consecutively and who were in accordance with the inclusion criteria of this study showed postoperative condylar resorption (group I). Preoperative cephalometric characteristics and surgically induced movements of this group were compared with a control group of 17 of 452 patients (group II) in whom postoperative condylar resorption and skeletal relapse did not develop, despite mandibular retrognathism (ANB angle >4 degrees) and high mandibular plane angle (>40 degrees). RESULTS The kind of osteosynthesis used was not significantly different between the 2 groups. The amount of surgical advancements and the vertical movements of the jaws were not significantly different between the 2 groups. However, the distal (P =.005) and proximal (P =.007) mandibular segments were rotated significantly further counterclockwise in group I. Surgically induced posterior condylar displacement occurred significantly more frequently (P =.007) in group I. CONCLUSIONS Counterclockwise rotation of the distal and proximal mandibular segments and surgically induced posterior condylar displacement seem to be important surgical risk factors for postoperative condylar resorption. Therefore, these movements seem to be contraindicated in patients who are at high risk.
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85 |
12
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Hwang SJ, Haers PE, Sailer HF. The role of a posteriorly inclined condylar neck in condylar resorption after orthognathic surgery. J Craniomaxillofac Surg 2000; 28:85-90. [PMID: 10958420 DOI: 10.1054/jcms.2000.0129] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recently, it has been reported that a posteriorly inclined condylar neck is associated with condylar resorption following orthognathic surgery, although its role in resorption remains unknown. By cephalometric screening of 240 patients with Angle Class II occlusion 2 years after orthognathic surgery, 11 patients with postoperative condylar resorption were identified. The preoperative posterior inclination of the condylar neck and the surgical risk factors mentioned in the literature, particularly surgically induced counterclockwise rotation of the mandibular proximal segment were evaluated. In all 11 cases, the condylar neck was clearly inclined posteriorly. Counterclockwise rotation of the proximal segment was also observed in all cases, and it amounted to 6.7 degrees (2.5-12 degrees) on average. The contributing role of a posteriorly inclined condylar neck in connection with surgical mandibular movement in postoperative condylar resorption is discussed.
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25 |
82 |
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Lee DW, Hwang SJ, Park JB, Park HJ. Preparation and release characteristics of polymer-coated and blended alginate microspheres. J Microencapsul 2010. [DOI: 10.3109/02652040309178060] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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15 |
81 |
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Chan CC, Hwang SJ, Lee FY, Wang SS, Chang FY, Li CP, Chu CJ, Lu RH, Lee SD. Prognostic value of plasma endotoxin levels in patients with cirrhosis. Scand J Gastroenterol 1997; 32:942-6. [PMID: 9299675 DOI: 10.3109/00365529709011206] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Endotoxemia has frequently been observed in patients with cirrhosis. Previous studies have shown that cirrhotic patients with endotoxemia have a higher mortality than those without. We evaluated the clinical value of plasma endotoxin level in predicting short-term (3 months) and long-term (2 years) survival among cirrhotic patients and compared it with the Child-Pugh score. METHODS Plasma endotoxin levels were determined in 102 cirrhotic patients without clinical evidence of infection by a quantitative Limulus assay. The patients were followed up for 3 months to assess short-term survival and for 2 years for long-term survival. RESULTS Plasma endotoxin levels increased progressively as liver function deteriorated. In short-term survival analysis, plasma endotoxin levels were significantly higher in non-survivors than those in survivors (10.6 +/- 2.2 pg/ml versus 5.8 +/- 0.5 pg/ml; P < 0.05). Both plasma endotoxin and serum bilirubin levels, but not the Child-Pugh score, were significant factors in predicting short-term survival in multivariate analysis. In long-term survival analysis, plasma endotoxin levels did not differ significantly between survivors and non-survivors (6.1 +/- 0.6 pg/ml versus 7.3 +/- 1.1 pg/ml; P > 0.05) and was not an independent predictor of long-term survival. In contrast, both Child-Pugh score and serum bilirubin levels were significant predictors of long-term survival in multivariate analysis. CONCLUSIONS In patients with cirrhosis, plasma endotoxin levels progressively increase as liver function deteriorates and may be useful in predicting short-term survival.
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Hwang SJ, Beaty TH, Liang KY, Coresh J, Khoury MJ. Minimum sample size estimation to detect gene-environment interaction in case-control designs. Am J Epidemiol 1994; 140:1029-37. [PMID: 7985651 DOI: 10.1093/oxfordjournals.aje.a117193] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
As genetic markers become more available, case-control studies will be increasingly important in defining the role of genetic factors in disease causality. The authors estimate the minimum sample size needed to assure adequate statistical power to detect gene-environment interaction. One assumption is made: the prevalence of exposure is independent of marker genotypes among controls. Given the assumption, six parameters (three odds ratios, the prevalence of exposure, the proportion of those with the susceptible genotype, and the ratio of controls to cases) dictate the expected cell sizes in a 2 x 2 x 2 table contrasting genetic susceptibility, exposure, and disease. The three odds ratios reflect the association between disease and 1) exposure among non-susceptibles; 2) susceptible genotypes among nonexposed individuals; and 3) the gene-environment interaction itself, respectively. Given these parameters, the number of cases and controls needed to assure any particular Type I and Type II error rates can be estimated. Results presented here demonstrate that case-control designs can be used to detect gene-environment interaction when there is both a common exposure and a highly polymorphic marker of susceptibility.
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31 |
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Kim BK, Hwang SJ, Park JB, Park HJ. Preparation and characterization of drug-loaded polymethacrylate microspheres by an emulsion solvent evaporation method. J Microencapsul 2002; 19:811-22. [PMID: 12569029 DOI: 10.1080/0265204021000022770] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Microspheres containing the anti-hypertension drug, felodipine, were prepared by the emulsion solvent evaporation method (o/o) using acrylate methacrylate copolymers, Eudragit RL PO and Eudragit RS PO, as wall materials. In order to increase the encapsulation efficiency, a mixed solvent system comprising 1:1 proportions of acetonitrile and dichloromethane was used as a dispersed phase. The morphology of the microspheres was evaluated using a scanning electron microscope, which showed a spherical shape with smooth surface. The mean sphere diameter was between 9.5-13.2 microm and the microencapsulation efficiencies ranged from 51.4-80.4%. The release profiles and encapsulation efficiencies depended strongly on the structure of the polymers used as wall materials. The release rate of the Eudragit RS PO microspheres was much lower than that of Eudragit RL PO microspheres. Whereas Eudragit RL PO microspheres followed the Higuchi rule, Eudragit RS PO microspheres exhibited a triphasic release profile. It is concluded that drug release rate can be controlled by choice of polymer type.
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77 |
17
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Chu CW, Hwang SJ, Luo JC, Lai CR, Tsay SH, Li CP, Wu JC, Chang FY, Lee SD. Clinical, virologic, and pathologic significance of elevated serum alpha-fetoprotein levels in patients with chronic hepatitis C. J Clin Gastroenterol 2001; 32:240-4. [PMID: 11246354 DOI: 10.1097/00004836-200103000-00014] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Elevated serum alpha-fetoprotein (AFP) in patients with chronic hepatitis C is not uncommonly seen, but the pathogenesis of this phenomenon remains unclear. The aims of this study were to assess the prevalence of elevated serum AFP in patients with chronic hepatitis C and to evaluate the clinical, virologic, and histopathologic significance of this phenomenon. One hundred and fifteen Chinese patients with a histologic diagnosis of chronic hepatitis C were enrolled. None had evidence of hepatocellular carcinoma by image study at enrollment and for at least 2 years' follow-up. Of the 115 patients, 33 (29%) had elevated serum AFP (more than 12 ng/mL). There was a significantly lower mean serum albumin (4.0 +/- 0.1 vs. 4.3 +/- 0.1 gm/dL, p <0.001) and higher mean scores for periportal necroinflammation (3.3 +/- 0.3 vs. 2.3 +/- 0.2, p = 0.007) and fibrosis (2.3 +/- 0.2 vs. 1.1 +/- 0.1, p < 0.001) in patients with elevated serum AFP when compared with patients without elevated serum AFP. Patients with elevated serum AFP had significantly more incidences of genotype 1b infection when compared with patients without elevated serum AFP (77% vs. 51%, p = 0.021). Mean serum hepatitis C virus (HCV) RNA titer showed no significant difference between the two groups. Multivariate logistic regression analysis showed that as serum albumin of less than 4.2 gm/dL, a histology fibrotic score of more than 3, and HCV genotype 1b infection were significantly independent predictors associated with elevated serum AFP. In conclusion, elevated serum AFP levels were significantly correlated with lower serum albumin levels, advanced fibrosis/cirrhosis, and genotype 1b infection in patients with chronic hepatitis C.
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McDaniel R, Kao CM, Hwang SJ, Khosla C. Engineered intermodular and intramodular polyketide synthase fusions. CHEMISTRY & BIOLOGY 1997; 4:667-74. [PMID: 9331407 DOI: 10.1016/s1074-5521(97)90222-2] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Modular polyketide synthases (PKSs) are very large multifunctional enzyme complexes that synthesize a number of medicinally important natural products. The modular arrangement of active sites has made these enzyme systems amenable to combinatorial manipulation for the biosynthesis of novel polyketides. Here, we investigate the involvement of subunit interactions in hybrid and artificially linked PKSs with several series of intermodular and intramodular fusions using the erythromycin (6-deoxyerythronolide B synthase; DEBS) and rapamycin (RAPS) PKSs. RESULTS Several two-module and three-module derivatives of DEBS were constructed by fusing module 6 to either module 2 or module 3 at varying junctions. Polyketide production by these intramodular fusions indicated that the core set of active sites remained functional in these hybrid modules, although the ketoreductase domain of module 6 was unable to recognize unnatural triketide and tetraketide substrates. Artificial trimodular PKS subunits were also engineered by covalently linking modules 2 and 3 of DEBS, thereby demonstrating the feasibility of constructing single-chain PKSs. Finally, a series of fusions containing DEBS and RAPS domains in module 2 of an engineered trimodular PKS revealed the structural and functional tolerance for hybrid modules created from distinct PKS gene clusters. CONCLUSIONS The general success of the intermodular and intramodular fusions described here demonstrates significant structural tolerance among PKS modules and subunits and suggests that substrate specificity, rather than protein-protein interactions, is the primary determinant of molecular recognition features of PKSs. Furthermore, the ability to artificially link modules may considerably simplify the heterologous expression of modular PKSs in higher eukaryotic systems.
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Idler DR, Bazar LS, Hwang SJ. Fish gonadotropin(s). II. Isolation of gonadotropin(s) from chum salmon pituitary glands using affinity chromatography. ENDOCRINE RESEARCH COMMUNICATIONS 1975; 2:215-35. [PMID: 170056 DOI: 10.3109/07435807509053850] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A highly purified gonadotropic hormone preparation has been obtained from chum salmon (Oncorhynchus keta) pituitaries by extraction with ethanolic or aqueous buffer, affinity chromatography on Con A Sepharose and gel filtration on Sephadex G-75 superfine. A purified fraction from Sephadex G-75 averaged 448 mug NIH-LH-S18/mg glycoprotein as measured by the uptake of radiophosphate into chick testes. A total of 1.1 g of salmon gonadotropin (s) (SG)/kg fresh tissue was recovered when the isolation began with an aqueous extraction. Analytical polyacrylamide gel electrophoresis (P.A.G.E.) of the purified fraction from Sephadex G-75 displayed a single broad zone in non-dissociating conditions and two bands in 8 M urea. Polyacrylamide gel electrofocusing yielded six sharp bands with an isoelectric point range of 4.38 to 5.05, and four bands with an isoelectric point range of 4.31 to 4.95 in 8 M urea. A molecular weight of 41,000 was determined by gel filtration. A subunit molecular weight of 17,800 +/- 10% was found by P.A.G.E. in 0.1% sodium dodecyl sulphate (SDS), suggesting that native SG consists of two subunits. Purified preparations were highly stable in Tris-Cl buffers and retained their activity for several months when stored at -73 degrees C.
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Hwang SJ, Lin HC, Chang CF, Lee FY, Lu CW, Hsia HC, Wang SS, Lee SD, Tsai YT, Lo KJ. A randomized controlled trial comparing octreotide and vasopressin in the control of acute esophageal variceal bleeding. J Hepatol 1992; 16:320-5. [PMID: 1487608 DOI: 10.1016/s0168-8278(05)80663-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This randomized controlled trial was conducted to compare the efficacy of intravenous infusion of octreotide (a synthetic long-acting somatostatin analogue) with vasopressin in 48 cirrhotic patients with endoscopically proven bleeding esophageal varices. Twenty-four patients received a continuous infusion of octreotide 25 micrograms/h for 24 h after an initial bolus of 100 micrograms and another 24 patients received a continuous infusion of vasopressin 0.4 U/min for 24 h. Bleeding was initially controlled after 6 h of drug infusion in 88% (21/24) and 54% (13/24) of the patients treated with octreotide and vasopressin respectively (p = 0.03). Complete control of bleeding after 24 h of drug infusion was achieved in 15 (63%) patients receiving octreotide and in 11 (46%) patients receiving vasopressin (p > 0.05). Side effects during drug infusion such as headache, chest pain and abdominal pain were significantly lower in the octreotide group (3/24) than in the vasopressin group (11/24). Serum gastrin and insulin levels fell significantly following octreotide infusion, but plasma glucose levels remained unchanged. Mortality related to bleeding esophageal varices was no different between the two groups. This report showed that octreotide infusion was more effective and had fewer side effects than vasopressin in initial controlling of acute esophageal variceal bleeding until an elective endoscopic sclerotherapy could be performed.
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Tsai YC, Hung CC, Hwang SJ, Wang SL, Hsiao SM, Lin MY, Kung LF, Hsiao PN, Chen HC. Quality of life predicts risks of end-stage renal disease and mortality in patients with chronic kidney disease. Nephrol Dial Transplant 2009; 25:1621-6. [DOI: 10.1093/ndt/gfp671] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Chou KJ, Fang HC, Bai KJ, Hwang SJ, Yang WC, Chung HM. Tuberculosis in maintenance dialysis patients. Nephron Clin Pract 2001; 88:138-43. [PMID: 11399916 DOI: 10.1159/000045974] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In this investigation, we tried to find the incidence and characteristics of tuberculosis (TB) in dialysis patients previously found only in a small number of cases. We collected the cases of newly diagnosed TB patients in Taiwan during 1997. Simultaneously, all dialysis patients were collected and matched with the TB cases to identify the dialysis patients who had also contracted TB. The annual incidence of the dialysis population was 493.4/100,000, 6.9 times that of the general population (71.1/100,000). The annual incidence for the male dialysis population was 573.3, the incidence was 479.2 for the female dialysis population. The incidence for the general population was 97.1 and 43.7/100,000, respectively. Although the 1-year mortality rate due to TB (1.7 vs. 1.9%, p > 0.05) was similar in both populations, the non-TB mortality was much higher in the dialysis population than that in the general population (25.6 vs. 11.1%, p < 0.05). Finally, the 1-year mortality rate of dialysis patients with TB is 3.3 times higher than that in dialysis patients without TB (27.3 vs. 8.3%, p < 0.05). The findings suggest that uremia modifies the behavior of TB, jeopardizes female and younger dialysis patients, poses a higher risk of extrapulmonary dissemination, and predicts a higher overall mortality.
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Hsu CC, Chang HY, Huang MC, Hwang SJ, Yang YC, Lee YS, Shin SJ, Tai TY. HbA1c variability is associated with microalbuminuria development in type 2 diabetes: a 7-year prospective cohort study. Diabetologia 2012; 55:3163-72. [PMID: 22923064 DOI: 10.1007/s00125-012-2700-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 07/25/2012] [Indexed: 12/16/2022]
Abstract
AIMS/HYPOTHESIS HbA(1c) variability has been shown to be an independent risk factor for nephropathy in patients with type 1 diabetes. In this study, we aimed to explore the association between HbA(1c) variability and microalbuminuria development in patients with type 2 diabetes. We also intended to test the applicability of serially measured HbA(1c) over 2 years for this risk assessment. METHODS Between 2003 and 2005, we recruited 821 middle-aged normoalbuminuric individuals with type 2 diabetes and followed them through to the end of 2010. The average follow-up time was 6.2 years. We defined microalbuminuria as a urine albumin to creatinine ratio of 30 mg/g (3.4 mg/mmol) or higher. HbA(1c) variability was calculated by the SD of serially measured HbA(1c). The Cox proportional hazards model was used to evaluate the association between HbA(1c) SD quartile and development of microalbuminuria. RESULTS The incidence of microalbuminuria for the overall population was 58.4, 58.6, 60.8 and 91.9 per 1,000 person-years for Q1- to Q4-adjusted HbA(1c) SD, respectively (p for trend = 0.042). Compared with patients in Q1, those in Q4 were about 37% more likely to develop microalbuminuria. The HR derived from a series of 2 year HbA(1c) measurements was similar to that from data collection for longer than 4 years. CONCLUSIONS/INTERPRETATION In addition to mean HbA(1c) values, HbA(1c) variability, even measured as early as 2 years, is independently associated with the development of microalbuminuria in patients with type 2 diabetes.
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Lee JH, Kim MJ, Choi WS, Yoon PY, Ahn KM, Myung H, Hwang SJ, Seo BM, Choi JY, Choung PH, Kim SM. Concomitant reconstruction of mandibular basal and alveolar bone with a free fibular flap. Int J Oral Maxillofac Surg 2004; 33:150-6. [PMID: 15050071 DOI: 10.1054/ijom.2003.0487] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2003] [Indexed: 11/18/2022]
Abstract
Repair of long-span mandibular defects with a free fibular flap is now a routine procedure. However, the bone height of the neo-mandible after reconstruction with a fibular flap is about half that of the dentulous mandible. When a fibular graft is placed only at the inferior border of the mandible, the resulting vertical discrepancy between the graft segment and the occlusal plane can adversely affect implant mechanics or denture stability and retention. To overcome these problems, we developed a technique for two-strut type mandibular reconstruction. A vascularized fibular segment is used to reconstruct the inferior basal portion of the neo-mandible, while a non-vascularized residual fibular segment is used to simulate the superior alveolar portion. We used this technique in 22 patients. Graft survival, graft resorption, and the ability to place implants were assessed as compared with those after the conventional one-strut type technique. The fibular segment grafted to the alveolar region was removed in one patient with intraoral wound dehiscence and in two with postoperative infection. All vascularized fibular flaps were successful. The resorption rate was 13.6+/-7.2% for non-vascularized segments and 3.0+/-3.7% for vascularized segments. Dental implants were placed in five of our 22 patients. The crown:fixture length ratio was improved to 1:1.7, as compared with a ratio of 1:1.21 with use of a conventional fibular flap. We conclude that our technique is very easy and safe and provides substantially improved lower-lip and cheek support and implant-prosthetic mechanics than conventional procedures for the repair of long-span mandibular defects.
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Hwang SJ, Wu JC, Lee CN, Yen FS, Lu CL, Lin TP, Lee SD. A prospective clinical study of isoniazid-rifampicin-pyrazinamide-induced liver injury in an area endemic for hepatitis B. J Gastroenterol Hepatol 1997; 12:87-91. [PMID: 9076631 DOI: 10.1111/j.1440-1746.1997.tb00353.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In order to evaluate the incidence, predisposing factors and clinical course of antituberculous drug-induced liver injury in hepatitis B surface antigen (HBsAg)-positive carriers and non-carriers, in an area endemic for hepatitis B, we prospectively followed 240 patients (154 male, 86 female; mean age 40 years) who had received daily isoniazid, rifampicin, ethambutol and pyrazinamide for the treatment of pulmonary tuberculosis. Patients with heavy alcohol consumption, with pretreatment serum alanine aminotransferase (ALT) elevation and who had less than 3 months post-treatment follow-up were excluded from the study. Thirty-one (13%) patients were positive for serum HBsAg before treatment. Sixty-three (26%; 95% CI: 21-32%) patients developed antituberculous drug-induced liver injury. The incidence of drug-induced liver injury was significantly more frequent in patients > 35 years of age than in patients < or = 35 years of age (33 vs 17%; P < 0.05), but was not different between HBsAg carriers and non-carriers (29 vs 26%; P > 0.05). Using step-wise logistic regression analysis, patient age > 35 years was the only independent variable for predicting antituberculous drug-induced liver injury, while sex, acetylator phenotype, HBsAg carrier status and severity of tuberculosis were not. The peak serum ALT levels in antituberculous drug-induced liver injury were not significantly different between HBsAg carriers and non-carriers. Only one 61-year-old HBsAg carrier developed severe jaundice after 6 months antituberculous therapy; he subsequently died of hepatic failure. In conclusion, the incidence of antituberculous drug-induced liver injury was significantly higher in patients > 35 years of age than in patients < or = 35 years of age, but was not different between HBsAg carriers and non-carriers. Mortality occurred in an aged HBsAg carrier superimposed with antituberculous drug-induced liver injury.
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