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Yoon JH, Lee ST, Park YH. Inter- and intraspecific phylogenetic analysis of the genus Nocardioides and related taxa based on 16S rDNA sequences. INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY 1998; 48 Pt 1:187-94. [PMID: 9542088 DOI: 10.1099/00207713-48-1-187] [Citation(s) in RCA: 440] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The 16S rDNAs from 38 strains of the genus Nocardioides, two Aeromicrobium species and Terrabacter tumescens were directly sequenced and then analysed. The mean nucleotide similarity value between the type strains of validly described Nocardioides species was 96.1 +/- 3.0%. The mean nucleotide similarity value between the type strains of validly described Nocardioides species and the two Aeromicrobium species was 93.7 +/- 1.4% T. tumescens was distantly related to the genera Nocardioides and Aeromicrobium. The mean intraspecific nucleotide similarity value of 16S rDNA sequences from Nocardioides albus was 99.5 +/- 0.5%. The mean intraspecific nucleotide similarity of 16S rDNA sequences from Nocardioides simplex was 100%, except for N. simplex strains ATCC 13260, ATCC 19565 and ATCC 19566, which were shown not to be members of the genus Nocardioides. 'Nocardioides flavus' strains IFO 14396T and IFO 14397, and 'Nocardioides fulvus' JCM 3335T showed a 16S rDNA similarity value of 100% with Nocardioides luteus KCTC 9575T and Nocardioides albus JCM 5854. 'N. fulvus' IFO 14399 shared its highest 16S rDNA similarity with Nocardioides sp. ATCC 39419 at 99%. 'N. fulvus' IFO 14399 and Nocardioides sp. ATCC 39419 formed a phylogenetic lineage distinct from the genera Nocardioides and Aeromicrobium. 'Nocardioides thermolilacinus' strains IFO 14335T and IFO 14336 displayed a close relationship to the genus Streptomyces. From 16S rDNA sequence analyses, it is considered that some strains that have been attributed to the genus Nocardioides should be taxonomically re-evaluated.
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440 |
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Um IC, Kweon HY, Park YH, Hudson S. Structural characteristics and properties of the regenerated silk fibroin prepared from formic acid. Int J Biol Macromol 2001; 29:91-7. [PMID: 11518580 DOI: 10.1016/s0141-8130(01)00159-3] [Citation(s) in RCA: 272] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Structural characteristics and thermal and solution properties of the regenerated silk fibroin (SF) prepared from formic acid (FU) were compared with those of SF from water (AU). According to the turbidity and shear viscosity measurement, SF formic acid solution was stable and transparent, no molecular aggregations occurred. The sample FU exhibited the beta-sheet structure, while AU random coil conformation using Fourier transform infrared (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry. The effects of methanol treatment on samples were also examined. According to the measurement of crystallinity (XRD) and crystallinity index (FTIR), the concept of long/short-range ordered structure formation was proposed. Long-range ordered crystallites are predominantly formed for methanol treated SF film while SF film cast from formic acid favors the formation of short-range ordered structure. The relaxation temperatures of SF films measured by dynamic thermomechanical analysis supported the above mechanism due to the sensitivity of relaxation temperature on the short-range order.
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Comparative Study |
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272 |
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Park IK, Kim TH, Park YH, Shin BA, Choi ES, Chowdhury EH, Akaike T, Cho CS. Galactosylated chitosan-graft-poly(ethylene glycol) as hepatocyte-targeting DNA carrier. J Control Release 2001; 76:349-62. [PMID: 11578748 DOI: 10.1016/s0168-3659(01)00448-5] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lactobionic acid bearing galactose group was coupled with chitosan for liver specificity, and poly(ethylene glycol) (PEG) was grafted to galactosylated chitosan (GC) for stability in water and enhanced cell permeability. Complex formation of galactosylated chitosan-graft-PEG (GCP)/DNA complexes was confirmed by agarose gel electrophoresis. Compared to GC/DNA complex, the stability of GCP/DNA complex could be enhanced. Particle sizes of GCP/DNA complexes decreased as the charge ratio of GCP to DNA increased and had a minimum value around 27 nm at the charge ratio of 5. Conformational change of DNA did not occur after complex formation with GCP compared to conformation of DNA itself. GCP/DNA complexes were only transfected into Hep G2 having asialoglycoprotein receptors (ASGR), indicative of specific interaction of ASGR on cells and galactose ligands on GCP.
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Diav-Citrin O, Park YH, Veerasuntharam G, Polachek H, Bologa M, Pastuszak A, Koren G. The safety of mesalamine in human pregnancy: a prospective controlled cohort study. Gastroenterology 1998; 114:23-8. [PMID: 9428214 DOI: 10.1016/s0016-5085(98)70628-6] [Citation(s) in RCA: 141] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND & AIMS Mesalamine is a first-line drug in the treatment of inflammatory bowel disease. Information regarding human pregnancy experience with mesalamine has been scarce and uncontrolled despite its frequent use in women of childbearing age. The aim of this study was to examine the fetal safety of mesalamine. METHODS The Motherisk Program prospectively enrolled and followed up 165 women exposed to mesalamine during pregnancy, 146 of whom had first trimester exposure. Pregnancy outcome was compared with that of a matched control group, who were counseled for nonteratogenic exposure. RESULTS There was no increase in major malformations (1 of 127 [0.8%] for mesalamine vs. 5 of 131 [3.8%] for nonteratogenic controls; P = 0.23). There was an increase in the rate of preterm deliveries (13.0% for mesalamine vs. 4.7% for nonteratogenic controls; P = 0.02), a decrease in the mean maternal weight gain during pregnancy (13.1 +/- 6.3 kg for mesalamine vs. 15.6 +/- 6.0 kg for nonteratogenic controls; P = 0.0002), and a decrease in the mean birth weight (3253 +/- 546 g for mesalamine vs. 3461 +/- 542 g for nonteratogenic controls; P = 0.0005). There were no significant differences in the maternal obstetric history, rates of live births, miscarriages, pregnancy terminations, ectopic pregnancies, delivery method, or fetal distress between the groups. CONCLUSIONS This study suggests that mesalamine does not represent a major teratogenic risk in humans when used in the recommended doses.
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Clinical Trial |
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Lee J, Kim WS, Park YH, Park SH, Park KW, Kang JH, Lee SS, Lee SI, Lee SH, Kim K, Jung CW, Ahn YC, Ko YH, Park K. Nasal-type NK/T cell lymphoma: clinical features and treatment outcome. Br J Cancer 2005; 92:1226-30. [PMID: 15798768 PMCID: PMC2361983 DOI: 10.1038/sj.bjc.6602502] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Nasal-type NK/T cell lymphoma is an increasingly recognised disease entity of aggressive clinical behaviour. The objective of this study was to investigate clinical features and treatment outcomes in patients with nasal-type NK/T cell lymphoma. From January 1991 to December 2003, 26 patients diagnosed as nasal-type NK/T cell lymphoma were included in the analysis. One half of patients presented with poor performance status (ECOG ⩾2); 46% of patients were categorised as high intermediate or high-risk group according to IPI; and 46% of patients were diagnosed at advanced stage. The median survival for 26 patients with nasal-type NK/T cell lymphoma was 7.4 months (95% CI, 0.1, 16.9). The treatment outcome of primary anthracycline-based chemotherapy was poor: 60% CR rate in localised disease and 0% CR rate in advanced disease. After a median follow-up of 24.4 months (range 3.1–99.0) in patients with localised disease who had achieved a CR (range 29.6–165.7), three patients (50.0%) developed disease recurrence at 6.1, 21.8, and 52.1 months, respectively, and all patients presented with locoregional failure. The predictive factors for poor survival were of age greater than 60, advanced stage and poor performance in multivariate analysis. In conclusion, Nasal-type NK/T cell lymphomas showed a poor response to the conventional anthracycline-based chemotherapy, and thus an investigation for an innovative therapy is urgently needed to improve survival in these patients.
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Journal Article |
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138 |
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Park IK, Park YH, Shin BA, Choi ES, Kim YR, Akaike T, Cho CS, Park YK, Park YR. Galactosylated chitosan-graft-dextran as hepatocyte-targeting DNA carrier. J Control Release 2000; 69:97-108. [PMID: 11018549 DOI: 10.1016/s0168-3659(00)00298-4] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lactobionic acid bearing galactose group was coupled with chitosan for liver specificity, and dextran was grafted to galactosylated chitosan (GC) for stability in water. Compared to the GC/DNA complex, the stability of the galactosylated chitosan-graft-dextran (GCD)/DNA complex could be enhanced. The particle size of the GCD/DNA complexes decreased as the charge ratio of GCD to DNA increased. Conformational change of DNA did not occur after complex formation with GCD compared with the conformation of DNA itself. The GCD/DNA complexes were only transfected into Chang liver cells and that of Hep G2 having asialoglycoprotein receptors (ASGR), indicative of specific interaction of ASGRs on cells and galactose ligands on chitosan.
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134 |
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McGinnis KM, Gnegy ME, Park YH, Mukerjee N, Wang KK. Procaspase-3 and poly(ADP)ribose polymerase (PARP) are calpain substrates. Biochem Biophys Res Commun 1999; 263:94-9. [PMID: 10486259 DOI: 10.1006/bbrc.1999.1315] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We demonstrate here that both procaspase-3 (32 kDa) and PARP are calpain substrates. In calcium-channel opener maitotoxin-treated cells, a 30 kDa caspase-3 fragment is produced in a time and concentration-dependent manner. Formation of this fragment is prevented by calpain inhibitors but not by the pancaspase inhibitor, carbobenzoxy-Asp-CH(2)OC(O)-2,6-dichlorobenzene (Z-D-DCB) nor the selective proteasome inhibitor lactacystin. In maitotoxin-treated cells, PARP (113 kDa) is also cleaved into a 40 kDa immunoreactive fragment, in a calpain-inhibitor-sensitive manner. Both procaspase-3 and PARP are also cleaved in vitro by purified micro-calpain to a 30 kDa fragment and a 40 kDa fragment, respectively. Finally, we show that staurosporine-mediated caspase-3 activation is interrupted by maitotoxin pretreatment.
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Kim HJ, Bang SM, Lee J, Kwon HC, Suh C, Kim HJ, Lee JH, Ryoo BY, Park YH, Kwon JM, Oh SY, Lee HR, Kim K, Jung CW, Park K, Kim WS. High-dose chemotherapy with autologous stem cell transplantation in extranodal NK/T-cell lymphoma: a retrospective comparison with non-transplantation cases. Bone Marrow Transplant 2006; 37:819-24. [PMID: 16547486 DOI: 10.1038/sj.bmt.1705349] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To determine the role of high-dose chemotherapy and autologous stem cell transplantation (HDC/ASCT) in extranodal NK/T-cell lymphoma patients, we conducted a retrospective analysis. In our previous study, we searched for patients who had received HDC/ASCT and identified 16 eligible patients and compared the treatment outcome with historical control group (n=246). Nine patients received HDC/ASCT in the first (CR1) or second complete remission (CR2), while seven patients received HDC/ASCT as salvage. Twelve of 16 patients achieved or maintained CR after HDC/ASCT. Among the 12 patients, five patients relapsed. Estimated 2-year overall survival (OS) and relapse-free survival (RFS) rates were 71.3+/-12.4% and 25.8+/-14.3%, respectively. There was a tendency of better survival in patients who received HDC/ASCT as compared to those who did not (P=0.091). In subset analysis, patients who underwent HDC/ASCT at CR (P=0.049) and patients with stage III or IV (P=0.001) had a favorable outcome. Patients with NKIPI 3,4 or EUNKTL, who underwent HDC/ASCT had more prolonged survival without statistical significance (P=0.055 and 0.056). In conclusion, HDC/ASCT may be considered as a treatment option for patients with extranodal NK/T-cell lymphoma, especially those in CR, with advanced disease (stage III/IV or EUNKTL) and high NKIPI scores.
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Journal Article |
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128 |
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Yoo HS, Lee SU, Park KY, Park YH. Molecular typing and epidemiological survey of prevalence of Clostridium perfringens types by multiplex PCR. J Clin Microbiol 1997; 35:228-32. [PMID: 8968913 PMCID: PMC229544 DOI: 10.1128/jcm.35.1.228-232.1997] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Clostridium perfringens has been classified into five toxigenic types (A through E) on the basis of its capability to produce major lethal toxins (alpha, beta, epsilon, and iota toxins). Seroneutralization with mice or guinea pigs has been used to type each toxin, but this conventional method has some disadvantages. Therefore, we used a molecular biological technique to type the bacterium in the present study. A multiplex PCR was developed for this purpose. This method has several advantages in comparison with seroneutralization with mice or guinea pigs. By this method, we also investigated the most prevalent type(s) of the organism in Korean calves, piglets, and chickens showing clinical symptoms such as diarrhea, enterotoxemia, and necrotic enteritis. Only type A was isolated from calves and chickens, while type C (2 of 14 isolates), in addition to type A, was isolated from piglets. These results suggested that seroneutralization could be replaced by our new method and that type A of C. perfringens is the most prevalent type in livestock in Korea.
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research-article |
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Suh KS, Roh HR, Koh YT, Lee KU, Park YH, Kim SW. Clinicopathologic features of the intraductal growth type of peripheral cholangiocarcinoma. Hepatology 2000; 31:12-7. [PMID: 10613721 DOI: 10.1002/hep.510310104] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The clinicopathologic features of the intraductal growth (IG) type of peripheral cholangiocarcinoma (PCC) were examined retrospectively. Out of 112 patients who underwent surgery for PCC at Seoul National University Hospital, Seoul, Korea, between January 1980 and December 1997, 16 were classified as having the IG type. Thirteen were men and 3 were women. Their ages ranged from 38 to 73 years with a mean age of 55.9 years. Abdominal pain was the most common symptom and jaundice was found in 18.8%. Five patients had associated clonorchiasis and 6 patients experienced hepatolithiasis. Tumor sizes ranged from 0.5 cm to 14.0 cm with a mean of 4.3 cm. The tumor was located in the right lobe in 7 cases and the left lobe in 9 cases. Thirteen patients underwent major hepatic resection, and 3 underwent minor resection, involving a subsegmentectomy. Mucin was found in the bile in 4 cases. Pathology showed papillary adenocarcinoma with a background of adenomatous hyperplasia, and the absence of lymph node metastasis in all cases. The tumors were confined to the mucosa in 5 cases. Out of the 16 hepatic resections, 1 was palliative due to a positive margin. In 2 of the patients who underwent minor resections, recurrences developed, and 1 of these died 56 months after resection. Out of the 16 patients, 15 remain alive, ranging from 1 to 13 years, postoperatively. In conclusion, the IG type of PCC should be distinguished from other types of PCC because a favorable prognosis can be expected after complete surgical resection.
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Moon JS, Lee AR, Kang HM, Lee ES, Kim MN, Paik YH, Park YH, Joo YS, Koo HC. Phenotypic and genetic antibiogram of methicillin-resistant staphylococci isolated from bovine mastitis in Korea. J Dairy Sci 2008; 90:1176-85. [PMID: 17297092 DOI: 10.3168/jds.s0022-0302(07)71604-1] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Staphylococcus aureus belongs to the group of major contagious mastitis pathogens, whereas the coagulase-negative staphylococci (CNS) are also capable of causing opportunistic bovine mastitis. Many of these strains are resistant to penicillin or ampicillin because of the long-term use of beta-lactam antibiotics in agricultural and healthcare settings. Based on the simple and highly specific coagulase genotyping by PCR-RFLP used for discriminating among Staph. aureus strains, the relationship between phenotypic antibiogram and the polymorphism of coagulase gene was determined in this study. The staphylococci strains (835 Staph. aureus and 763 CNS) were isolated from 3,047 bovine mastitic milk samples from 153 dairy farms in 8 provinces from 1997 to 2004 in the Republic of Korea. Twenty-one (2.5%) Staph. aureus and 19 (2.4%) CNS strains were resistant to methicillin [oxacillin minimum inhibitory concentration (MIC) > or = 4 microg/mL]. The mecA gene was also found in 13 methicillin-resistant Staph. aureus (MRSA) and 12 methicillin-resistant CNS (MRCNS) isolates with a significantly higher detection rate of the mecA gene in MRSA with high MIC (> or = 16 microg/mL) compared with those with MIC < or = 8 microg/mL. Methicillin-resistant Staph. aureus and MRCNS were also more resistant to other antibiotics (ampicillin, cephalothin, kanamycin, and gentamicin) than methicillin-susceptible staphylococci. Among 10 different coa PCR-RFLP patterns (A to J) in 706 Staph. aureus strains, the main types were A (26.9%), B (17.0%), G (10.5%), and H (15.4%), with the frequent observation of the A and H types (6 and 10 isolates) in MRSA. This study indicates that major epidemic Staph. aureus clones may be spread between different dairy farms, and the profile of coa genotype can be applied for epidemiological investigations and control of bovine mastitis, particularly one caused by MRSA with specific prevalent coa types.
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Research Support, Non-U.S. Gov't |
17 |
116 |
12
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Kim YH, Chang WH, Bang OY, Kim ST, Park YH, Lee PKW. Long-term effects of rTMS on motor recovery in patients after subacute stroke. J Rehabil Med 2010; 42:758-64. [DOI: 10.2340/16501977-0590] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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109 |
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Moon HS, Choi YJ, Park YH, Kim SG. New simple endoscopic operations for interstitial pregnancies. Am J Obstet Gynecol 2000; 182:114-21. [PMID: 10649165 DOI: 10.1016/s0002-9378(00)70499-6] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVES Our aim was to report a new approach of endoscopic management (endoloop and encircling suture methods) for interstitial or cornual pregnancy and to determine the safety and effectiveness of these procedures and their effects on subsequent pregnancies. STUDY DESIGN This is an uncontrolled retrospective review of 24 patients treated for interstitial pregnancies through endoscopic operations with 14 to 72 months of follow-up at a large urban medical center. Blood loss, operation time, changes of serum human chorionic gonadotropin levels, the resumption of menstruation, and subsequent pregnancy after operation were analyzed. RESULTS Among 24 interstitial pregnancies, 3 had ruptured at the time of operation and 21 had not ruptured. Treatment consisted of either the vasopressin and electric cauterization method, the endoloop before evacuation of the conceptus method, or the encircling suture before evacuation of the conceptus method. The blood loss and operation time (mean +/- SD) for unruptured cases were 133 +/- 134 mL and 51.6 +/- 7.6 minutes in the vasopressin and electric cauterization group (n = 3), 32 +/- 22 mL and 28.5 +/- 6.4 minutes in the endoloop group (n = 15), and 40 +/- 17 mL and 35.0 +/- 5.0 minutes in the encircling suture group (n = 3). In 3 patients with ruptured pregnancy treated with the endoloop method, the blood loss and operation time (mean +/- SD) were 1100 +/- 854 mL and 82.5 +/- 51.6 minutes. Any of these operative methods resulted in rapid decline of serum human chorionic gonadotropin levels within 1 week with the exception of 1 case, in which the endoloop method was used; this patient needed additional treatment with methotrexate. Seventeen patients desired pregnancy in the future, and 15 eventually became pregnant. One of these 15 pregnancies ended in an ectopic pregnancy on the opposite side 6 months after the interstitial pregnancy. Three ended in a spontaneous abortion, and 11 were delivered by elective cesarean section at term before labor started. Operative records of cesarean section in 8 patients delivered at our institution showed little or no adhesions or defect in the cornual area of the previous operation. CONCLUSION The endoloop method and the encircling suture method are simple, safe, effective, and nearly bloodless. There were no uterine ruptures in the pregnancies subsequent to these methods of endoscopic management.
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Comparative Study |
25 |
105 |
14
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Lee JS, Shin YK, Yoon JH, Takeuchi M, Pyun YR, Park YH. Sphingomonas aquatilis sp. nov., Sphingomonas koreensis sp. nov., and Sphingomonas taejonensis sp. nov., yellow-pigmented bacteria isolated from natural mineral water. Int J Syst Evol Microbiol 2001; 51:1491-1498. [PMID: 11491350 DOI: 10.1099/00207713-51-4-1491] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The taxonomic status of four strains from several mineral water sources in Taejon, Korea, was examined. The DNA base compositions of these strains ranged from 62 to 66 mol %. All of the strains contained sphingolipids and ubiquinone 10 as the main respiratory quinone. The cellular fatty acids of these strains included octadecenoic acid, hexadecanoic acid and 2-hydroxymyristic acid, without 3-hydroxy fatty acids. On the basis of morphological, physiological and chemotaxonomic characteristics, together with 16S rDNA sequence comparison and DNA-DNA reassociation data, three new species of the genus Sphingomonas are proposed for the strains isolated from natural mineral water: Sphingomonas aquatilis sp. nov. for strain JSS7T (= KCTC 2881T = KCCM 41067T), Sphingomonas koreensis sp. nov. for strains JSS26T (= KCTC 2882T = KCCM 41069T) and JSS28 (= KCTC 2883 = KCCM 41066) and Sphingomonas taejonensis sp. nov. for strain JSS54T (= KCTC 2884T = KCCM 41068T).
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Comparative Study |
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103 |
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Jeon HJ, Jeong YI, Jang MK, Park YH, Nah JW. Effect of solvent on the preparation of surfactant-free poly(DL-lactide-co-glycolide) nanoparticles and norfloxacin release characteristics. Int J Pharm 2000; 207:99-108. [PMID: 11036235 DOI: 10.1016/s0378-5173(00)00537-8] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The surfactant-free nanoparticles of poly(DL-lactide-co-glycolide) (PLGA) were prepared by dialysis method without surfactant and physicochemical properties such as particle size and drug contents were investigated against used initial solvent. The size of PLGA nanoparticles and drug contents were significantly changed by used initial solvent. The size of PLGA nanoparticles prepared from dimethylacetamide (DMAc), dimethylformamide (DMF), and dimethylsulfoxide (DMSO) as a initial used solvent was smaller than that of acetone. Selected initial solvent used to dissolve the copolymer significantly affects the size of nanoparticles and drug contents. It was shown that PLGA nanoparticles have spherical shapes from the results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations. It was thought that surfactant-free nanoparticles of PLGA entrapping norfloxacin (NFX) has nice drug loading capacity without free-drug on the surface of nanoparticles through the analysis of X-ray powder diffraction. From these results, it was showed the potential that the PLGA nanoparticles could be formed successively by dialysis method without surfactant. Release kinetics of NFX used as a model drug was governed by not only drug contents but also particle size parameter. The higher the drug contents and the larger the particle size resulted in slower the drug release.
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101 |
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Ha HK, Lee HJ, Kim H, Ro HJ, Park YH, Cha SJ, Shinn KS. Abdominal actinomycosis: CT findings in 10 patients. AJR Am J Roentgenol 1993; 161:791-4. [PMID: 8372760 DOI: 10.2214/ajr.161.4.8372760] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE The purpose of this study was to analyze the CT findings in 10 patients with abdominal actinomycosis to determine the appearance of lesions and the pattern of spread of the disease. MATERIALS AND METHODS We retrospectively reviewed the CT findings in 10 patients with pathologically proved actinomycosis. Involved areas were the pelvis (n = 4), greater omentum (n = 3), liver (n = 2), and kidney (n = 1). Contrast-enhanced (oral and IV) CT scans were available in all patients. Unenhanced CT scans were also available in six patients. RESULTS CT scans showed mostly solid masses with focal areas of diminished attenuation in seven patients and mostly cystic masses with thickened walls in three. CT findings confirmed the infiltrative nature of the disease, showing its tendency to invade across tissue planes and boundaries. Dense inhomogeneous contrast enhancement in the walls or solid components of masses was seen in eight patients. Minimal lymphadenopathy was seen in only two patients. CONCLUSION Although nonspecific, actinomycosis should be included in the differential diagnosis when CT scans show an infiltrative mass with unusual aggressiveness and dense inhomogeneous contrast enhancement, especially in patients with fever, leukocytosis, or long-term use of intrauterine contraceptive devices.
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Park YH, Fox LK, Hamilton MJ, Davis WC. Bovine mononuclear leukocyte subpopulations in peripheral blood and mammary gland secretions during lactation. J Dairy Sci 1992; 75:998-1006. [PMID: 1578038 DOI: 10.3168/jds.s0022-0302(92)77842-4] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Florescence flow cytometry and monoclonal antibodies were used to analyze the composition of leukocytes from peripheral blood and mammary gland secretions. Samples were obtained from Holstein dairy cows, free of IMI, at six time points during the lactation cycle. The percentage of monocytes in peripheral blood mononuclear cells varied from 15 to 31%; the lowest percentage occurred at the early nonlactation period. The percentage of T lymphocytes from mammary gland secretions varied from 16% during the periparturient period to 62% at late lactation. The B lymphocytes varied from 7% at late lactation to 25% during the periparturient period. Macrophages varied from 21 to 69%; the highest percentage occurred during the periparturient period. The mean ratio of CD4+:CD8+ T lymphocytes in the peripheral blood and mammary gland secretions was 1.53 and .85, respectively. A subpopulation of activated CD8+ T lymphocytes present in mammary gland secretions throughout the lactation cycle coexpressed a new activation molecule, ACT2. Increases in the proportion of CD8+ T lymphocytes were associated with an increase in the percentage of CD8+, ACT2+ T lymphocytes. Activated CD8+ T lymphocytes may play an important role in the regulation and expression of the local immune response to pathogens.
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33 |
99 |
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Ojima I, Slater JC, Kuduk SD, Takeuchi CS, Gimi RH, Sun CM, Park YH, Pera P, Veith JM, Bernacki RJ. Syntheses and structure-activity relationships of taxoids derived from 14 beta-hydroxy-10-deacetylbaccatin III. J Med Chem 1997; 40:267-78. [PMID: 9022793 DOI: 10.1021/jm960563e] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A series of new taxoids derived from 14 beta-hydroxy-10-deacetylbaccatin III was synthesized by means of the beta-lactam synthon method. Most of the new taxoids thus synthesized possess excellent cytotoxicity against human ovarian (A121), non-small-cell lung (A549), colon (HT-29), and breast (MCF-7) cancer cell lines, and several of these taxoids show subnanomolar IC50 values which are severalfold to 1 order of magnitude better than those of paclitaxel and docetaxel. Modifications at the 3'- and 3'-N-positions exert marked effects on the activity. For the substituents at C-3', the cytotoxicity decreases in the order 2-furyl approximately 2-methyl-1-propenyl > or = 2-methylpropyl > (E)-1-propenyl > or = n-propyl > phenyl > > 2,2-dimethylpropyl. For the 3'-N substituents, the activity decreases in the order t-BuOCO > Ph > n-hexanoyl. A significant increase in the cytotoxicity against the doxorubicin-resistant human breast cancer cell line MCF7-R that expresses the multidrug resistance (MDR) phenotype is observed by the proper modification of the substituent at C-10. The observed remarkable effects of the substituents at C-10 on the activity against MCF7-R can be ascribed to the effective inhibition of the binding of these new taxoids to P-glycoprotein that is responsible for MDR.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Antineoplastic Agents, Phytogenic/chemical synthesis
- Antineoplastic Agents, Phytogenic/chemistry
- Antineoplastic Agents, Phytogenic/metabolism
- Antineoplastic Agents, Phytogenic/pharmacology
- Docetaxel
- Drug Resistance, Multiple
- Drug Resistance, Neoplasm
- Drug Screening Assays, Antitumor
- Humans
- Magnetic Resonance Spectroscopy
- Molecular Conformation
- Molecular Structure
- Paclitaxel/analogs & derivatives
- Paclitaxel/chemical synthesis
- Paclitaxel/chemistry
- Paclitaxel/metabolism
- Paclitaxel/pharmacology
- Structure-Activity Relationship
- Taxoids
- Tumor Cells, Cultured
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Comparative Study |
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Abstract
The use of 131I doses of several mCi for scans can stun the thyrocytes and thyroid cancer cells, whereas the usual dose (300 microCi) of 123I does not. We compared the diagnostic accuracy of the 123I (300 microCi) scans and that of 131I (3-10 mCi) scans in 155 patients. The diagnostic accuracy of a 123I scan in detecting functioning thyroid remnant/metastasis was 89.5% (77/86 scans) and that of a 131I scan was 92.9% (39/42) in 6 week-postoperative patients (p = 0.750). For radioablation therapy follow-up patients, the diagnostic accuracy of 123I in determining presence or absence of functioning remnant or metastasis was 69.4% (25/36) and that of 131I was 92.5% (49/53) with a p value of 0.079. The success rates for complete ablation of functioning tissue after radioiodine therapy administered after diagnostic 123I and after 131I were 72% (34/47) and 56% (24/43), respectively, with a p value of 0.125. Our study indicates the following: 1) for the first postoperative evaluation, the diagnostic accuracy of the 123I scan was essentially equal to that of the 131I scan, and the success rate of radioablation therapy appears to be better than 123I scan; and 2) for postablation follow-up surveys, the 131I scan appears to be better but carries the risk of stunning the functioning cells.
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Hong YF, Kang JG, Lee HY, Uhm HS, Moon E, Park YH. Sterilization effect of atmospheric plasma on Escherichia coli and Bacillus subtilis endospores. Lett Appl Microbiol 2008; 48:33-7. [PMID: 19018968 DOI: 10.1111/j.1472-765x.2008.02480.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS Escherichia coli and Bacillus subtilis spores were treated with an atmospheric plasma mixture created by the ionization of helium and oxygen to investigate the inactivation efficiency of a low-temperature plasma below 70 degrees C. METHODS AND RESULTS An electrical discharge plasma was produced at a radio frequency (RF) of 13.56 MHz, connected to a perforated circular electrode with a discharge spacing of 1-15 mm. The discharge gas was helium with 0-2% oxygen. For the plasma treatment, a dried E. coli cell or B. subtilis endospore suspension on a cover-glass was exposed to oxygen downstream of the plasma from holes in an RF-powered electrode. The sterilization effect of the RF plasma was highest with 0.2% oxygen, corresponding to the maximum production of oxygen radicals. CONCLUSIONS Oxygen radicals generated by RF plasma are effective for the destruction of bacterial cells and endospores. SIGNIFICANCE AND IMPACT OF THE STUDY Low-temperature atmospheric plasma can be used for the disinfection of diverse objects, especially for the inactivation of bacterial endospores.
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Journal Article |
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Hwang SS, Kim HH, Park SH, Kim SE, Jung JI, Ahn BY, Kim SH, Chung SK, Park YH, Choi KH. N-butyl-2-cyanoacrylate pulmonary embolism after endoscopic injection sclerotherapy for gastric variceal bleeding. J Comput Assist Tomogr 2001; 25:16-22. [PMID: 11176287 DOI: 10.1097/00004728-200101000-00003] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE The purpose of this work was to describe the radiologic and clinical manifestations of n-butyl-2-cyanoacrylate pulmonary embolism (PE) after endoscopic injection sclerotherapy (EIS) for gastric variceal bleeding. METHOD From 1992 to 1999, the medical records of 140 patients who had undergone EIS using n-butyl-2-cyanoacrylate were reviewed for identification of respiratory symptoms and amount of injection, and their pre- and postprocedure chest radiographs were reviewed to identify PE. In patients with PE, pre- and postprocedure chest radiographs (6/6), chest CT scans (3/6), lung perfusion scans (3/6), and follow-up chest radiographs (6/6) were analyzed retrospectively. RESULTS Radiographically evident PE was observed in 6 (4.3%) of 140 patients. In comparison with patients without emboli, these patients received a higher mean volume of injection (4.2 vs. 1.8 ml) (p = 0.0011). Four of the six patients with pulmonary emboli had respiratory symptoms. Chest radiographs and CT scans showed unusual tubular or nodular, radiopaque pulmonary emboli along the pulmonary vessels. Multiple peripheral, wedge-shaped, subsegmental perfusion defects were seen on perfusion lung scans. In five of six patients, the radiographic abnormalities showed complete or partial resolution. There were no fatalities directly associated with PE. CONCLUSION Radiographically evident PEs are uncommonly observed following EIS and appear to be more common in patients receiving a higher volume of liquid acrylate. Affected patients were either mildly symptomatic or asymptomatic, and there were no direct fatalities of this complication.
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Comparative Study |
24 |
91 |
22
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Yoon JH, Lee KC, Weiss N, Kho YH, Kang KH, Park YH. Sporosarcina aquimarina sp. nov., a bacterium isolated from seawater in Korea, and transfer of Bacillus globisporus (Larkin and Stokes 1967), Bacillus psychrophilus (Nakamura 1984) and Bacillus pasteurii (Chester 1898) to the genus Sporosarcina as Sporosarcina globispora comb. nov., Sporosarcina psychrophila comb. nov. and Sporosarcina pasteurii comb. nov., and emended description of th. Int J Syst Evol Microbiol 2001; 51:1079-1086. [PMID: 11411676 DOI: 10.1099/00207713-51-3-1079] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A light-orange-coloured, facultatively anaerobic, rod-shaped bacterium (strain SW28T), which was isolated from seawater in Korea, was taxonomically studied by a polyphasic approach. This organism formed round terminal endospores in swollen sporangia. The peptidoglycan type is A4alpha, based on L-Lys-L-Ala-D-Asp. The predominant menaquinone is MK-7 and the major fatty acid is ante-C15:0. The G+C content of the DNA is 40 mol%. Phylogenetic analysis based on 16S rDNA sequences showed that strain SW28T falls within the radiation of a cluster comprising the rRNA group 2 bacilli and non-Bacillus-type organisms. Strain SW28T showed the highest degree of relatedness to the type strain of Sporosarcina ureae, sharing 96.8% 16S rDNA similarity. Levels of DNA-DNA relatedness between strain SW28T and S. ureae DSM 2281T and the type strains of some Bacillus species forming a coherent phylogenetic cluster are less than 12.5%. On the basis of phenotypic and chemotaxonomic characteristics, 16S rDNA sequence analysis and DNA-DNA relatedness data, it is proposed that strain SW28T should be placed in the genus Sporosarcina as a new species, Sporosarcina aquimarina sp. nov. The type strain is SW28T (= KCCM 41039T = JCM 10887T). From the results of the taxonomic re-evaluation, it is also proposed that Bacillus globisporus, Bacillus psychrophilus and Bacillus pasteurii be transferred to the genus Sporosarcina as Sporosarcina globispora, Sporosarcina psychrophila and Sporosarcina pasteurii, respectively.
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Comparative Study |
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88 |
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Kim DH, Baek JH, Chae YS, Kim YK, Kim HJ, Park YH, Song HS, Chung JS, Hyun MS, Sohn SK. Absolute lymphocyte counts predicts response to chemotherapy and survival in diffuse large B-cell lymphoma. Leukemia 2007; 21:2227-30. [PMID: 17554383 DOI: 10.1038/sj.leu.2404780] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
MESH Headings
- Antigens, CD20/biosynthesis
- Antineoplastic Combined Chemotherapy Protocols/administration & dosage
- Cyclophosphamide/administration & dosage
- Doxorubicin/administration & dosage
- Humans
- Lymphocyte Count
- Lymphocytes/cytology
- Lymphoma, B-Cell/drug therapy
- Lymphoma, B-Cell/mortality
- Lymphoma, B-Cell/pathology
- Lymphoma, Large B-Cell, Diffuse/drug therapy
- Lymphoma, Large B-Cell, Diffuse/mortality
- Lymphoma, Large B-Cell, Diffuse/pathology
- Medical Oncology/methods
- Multivariate Analysis
- Odds Ratio
- Prednisolone/administration & dosage
- Prognosis
- Time Factors
- Treatment Outcome
- Vincristine/administration & dosage
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Letter |
18 |
87 |
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Park YH, Zhang X, Rubakhin SS, Sweedler JV. Independent optimization of capillary electrophoresis separation and native fluorescence detection conditions for indolamine and catecholamine measurements. Anal Chem 1999; 71:4997-5002. [PMID: 10565288 DOI: 10.1021/ac990659r] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Separation conditions in capillary electrophoresis with native fluorescence detection often represent a compromise in terms of the separation and detection figures of merit. As both the separation and fluorescence properties greatly depend on pH, the ability to independently optimize pH in the separation capillary and the detection region can improve many complex separations. When using a sheath flow cell, the pH at the detection zone can be adjusted independently of the electrophoresis buffer pH. Using capillary electrophoresis with 257-nm excitation and native fluorescence detection, more than an order of magnitude improvement in the limits of detection for dopamine (from 1400 to 120 nM) and epinephrine (from 850 to 60 nM) is achieved by maintaining the basic separation conditions and an acidified sheath buffer. The detection of dopamine in an individual Aplysia californica cerebral ganglion neuron is demonstrated.
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Park IK, Ihm JE, Park YH, Choi YJ, Kim SI, Kim WJ, Akaike T, Cho CS. Galactosylated chitosan (GC)-graft-poly(vinyl pyrrolidone) (PVP) as hepatocyte-targeting DNA carrier. Preparation and physicochemical characterization of GC-graft-PVP/DNA complex (1). J Control Release 2003; 86:349-59. [PMID: 12526830 DOI: 10.1016/s0168-3659(02)00365-6] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Galactosylated chitosan was conjugated with poly(vinyl pyrrolidone) (PVP) as a hydrophilic group. The complex formation of GC-graft-PVP (GCPVP)/DNA complexes was confirmed by agarose gel electrophoresis. The morphology of the complex observed by atomic force microscopy had a compact and spherical shape, around 40 nm particle sizes at a charge ratio of 3. The binding strength of GCPVP 10K/DNA complex measured by ethidium bromide binding assay was superior to that of the GCPVP 50K/DNA one, probably attributable to its higher flexibility due to the smaller size, whereas the DNase I protection of GCPVP 10K/DNA complex was inferior to that of the GCPVP 50K/DNA one. This indicated that effective complex formation required both higher binding strength and minimal molecular weight of polycation enough to induce the condensation of DNA. The DNA-binding property of GCPVP mainly depended on the molecular weight of chitosan and composition of PVP.
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