576
|
Lee HS. Characterization of carotenoids in juice of red navel orange (Cara Cara). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2001; 49:2563-8. [PMID: 11368636 DOI: 10.1021/jf001313g] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
High-performance liquid chromatography with photodiode array detection was applied for the separation and characterization of carotenoids from a red-fleshed navel orange (Cara Cara). Carotenoid pigments were extracted using hexane/acetone/ethanol and saponified using 10% methanolic potassium hydroxide. More than 29 carotenoid pigments were separated within 60 min using a ternary gradient (75% acetonitrile/25% methanol, methyl tert-butyl ether, and water) elution on a C(30) reversed-phase column. The presence of lycopene (3.9 +/- 1.1 ppm) and a relatively large percentage of beta-carotene were distinct differences in the pigment profile of this red navel orange juice as compared to the profile of standard navel orange juice. The juice color in the red navel was much deeper orange than that from navel orange; hue angle ranged from 84.1 to 89.4 for red navel compared to 98.2 to 100.5 for standard navel.
Collapse
|
577
|
Jeong CK, Lee HY, Kim SB, Choi SJ, Kim JH, Kim K, Han SS, Lee HS. Metabolism of flupyrazofos in the isolated perfused rat liver. PEST MANAGEMENT SCIENCE 2001; 57:427-431. [PMID: 11374159 DOI: 10.1002/ps.291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To investigate the hepatic metabolism of the new insecticide flupyrazofos [O,O-diethyl O-(1-phenyl-3-trifluoromethylpyrazol-5-yl) phosphorothioate], isolated rat liver was perfused with flupyrazofos under single-pass conditions. In outflow perfusate and bile, 1-phenyl-3-trifluoromethyl-5-hydroxyprazole (PTMHP), PTMHP-sulfate and PTMHP-glucuronide conjugates were identified as the metabolites of flupyrazofos. However, O,O-diethyl O-(1-phenyl-3-trifluoromethylpyrazol-5-yl) phosphate (flupyrazofos oxon) was not detected. A HPLC method with UV detection was used to investigate the hepatic disposition of flupyrazofos and its metabolite PTMHP. The concentrations of flupyrazofos, PTMHP and PTMHP conjugates in outflow perfusate reached steady-state levels within 20 min after commencing perfusion of 7.3 microM flupyrazofos. At steady state, the mean extraction ratio of flupyrazofos was 0.93 (+/- 0.01) and clearance was 26.1 (+/- 0.2) ml min-1 which nearly approached perfusate flow rate (28 ml min-1). PTMHP accounted for 55.7 (+/- 5.8)% of eliminated flupyrazofos and was recovered as unchanged PTMHP, PTMHP-sulfate and PTMHP-glucuronide in the bile as well as the outflow perfusate.
Collapse
|
578
|
Han OJ, Joe KH, Kim SW, Lee HS, Kwon NS, Baek KJ, Yun HY. Involvement of p38 mitogen-activated protein kinase and apoptosis signal-regulating kinase-1 in nitric oxide-induced cell death in PC12 cells. Neurochem Res 2001; 26:525-32. [PMID: 11513480 DOI: 10.1023/a:1010917129951] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Although nitric oxide (NO) plays key signaling roles in the nervous systems, excess NO leads to cell death. In this study, the involvement of p38 mitogen-activated protein kinase (p38 MAPK) and apoptosis signal-regulating kinase-1 (ASK1) in NO-induced cell death was investigated in PC12 cells. NO donor transiently activated p38 MAPK in the wild type parental PC12 cells, whereas the p38 MAPK activation was abolished in NO-resistant PC12 cells (PC 12-NO-R). p38 MAPK inhibitors protected the cells against NO-induced death, whereas the inhibitors were not significantly protective against the cytotoxicity of reactive oxygen species. Stable transfection with dominant negative p38 MAPK mutant reduced NO-induced cell death. Stable transfection with dominant negative mutant of ASK1 attenuated NO-stimulated activation of p38 MAPK and decreased NO-induced cell death. These results suggest that p38 MAPK and its upstream regulator ASK1 are involved in NO-induced PC12 cell death.
Collapse
|
579
|
Cheon KW, Lee HS, Parhar IS, Kang IS. Expression of the second isoform of gonadotrophin-releasing hormone (GnRH-II) in human endometrium throughout the menstrual cycle. Mol Hum Reprod 2001; 7:447-52. [PMID: 11331667 DOI: 10.1093/molehr/7.5.447] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We examined the expression of the protein and mRNA of the newly cloned isoform of human gonadotrophin-releasing hormone (GnRH-II) in the normal human endometrium during the menstrual cycle. Nested RT-PCR and sequence analysis revealed that two spliced variants of GnRH-II mRNA were expressed during the entire menstrual cycle, with the shorter transcript having a 21 nucleotide deletion in the region coding for GnRH-associated peptide. Using immunohistochemistry, we identified immunoreactive GnRH-II in both stromal and glandular epithelial cells during the entire menstrual phase. The immunostaining intensity was stronger during the early and mid-secretory phase compared with the proliferative and late-secretory phase. A large amount of immunoreactive GnRH-II was localized in the apical pole of the glandular lumen. Our results show that the second isoform of GnRH (GnRH-II) is expressed in the human endometrium during the entire menstrual phase. We also suggest that an increased expression of endometrial GnRH-II peptide, noted during the early and mid-secretory phase, may play an important role in human embryo implantation.
Collapse
|
580
|
Lee HS, Park CK, Joo KB, Shin HJ, Kim Y, Park DW, Lee WM, Park YW. Subcutaneous bronchogenic cyst: unusual unltrasonographic findings. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2001; 20:563-566. [PMID: 11345117 DOI: 10.7863/jum.2001.20.5.563] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
581
|
Cho KW, Lee HS, Rho JR, Kim TS, Mo SJ, Shin J. New lactone-containing metabolites from a marine-derived bacterium of the genus Streptomyces. JOURNAL OF NATURAL PRODUCTS 2001; 64:664-667. [PMID: 11374972 DOI: 10.1021/np000599g] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Six novel metabolites containing a lactone moiety as a common structural feature, along with the previously described (-)-blastmycinolactol, have been isolated from the cultivation broth of a bacterium of the genus Streptomyces isolated from marine sediment. On the basis of the results of combined spectroscopic analysis, the structures of the new compounds have been determined as butenolides and 3-hydroxy-gamma-butyrolactones.
Collapse
|
582
|
Kim JW, Kim HJ, Kim Y, Lee MS, Lee HS. Properties of the Corynebacterium glutamicum metC gene encoding cystathionine beta-lyase. Mol Cells 2001; 11:220-5. [PMID: 11355704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023] Open
Abstract
The metC gene encoding the cystathionine beta-lyase, the third enzyme in the methionine biosynthetic pathway, was isolated from Corynebacterium glutamicum by heterologous complementation of the Escherichia coli metC mutant. A DNA-sequence analysis of the cloned DNA identified two open-reading frames (ORFs) of ORF1 and ORF2 that consisted of 1,107 and 978 bp, respectively. A SDS-PAGE analysis identified a putative cystathionine beta-lyase band with approximate Mr of 41,000 that consisted of 368 amino acids encoded from ORF1. The translational product of the gene showed no significant homology with that of the metC gene from other organisms. Introduction of the plasmid containing the metC gene into C. glutamicum resulted in a 5-fold increase in the activity of the cystathionine beta-lyase. The putative protein product of ORF2, encoding a protein product of 35,574 Da, consisted of 325 amino acids and was identical to the previously reported aecD gene product, except for the existence of two different amino acids. Like the aecD gene, when present in multiple copies, the metC gene conferred resistance to S-(betaaminoethyl)-cysteine, which is a toxic lysine analog. However, genetic and biochemical evidence suggests that the natural activity of the metC gene product is to mediate methionine biosynthesis in C. glutamicum. Mutant strains of metC were constructed, and the strains showed methionine prototrophy. The mutant strains completely lost their ability to show resistance to the S-(beta-aminoethyl)-cysteine. These results suggest that, in addition to the transsulfuration, other biosynthetic pathway(s), such as a direct sulfhydrylation pathway, may be functional in C. glutamicum as a parallel biosynthetic route for methionine.
Collapse
|
583
|
Choi SJ, Lee HY, Kim SB, Kim JH, Lee SS, Yoo SD, Lee KC, Lee HS. Determination of growth hormone-releasing hexapeptide by reversed-phase high-performance liquid chromatography with electrochemical detection. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 754:461-6. [PMID: 11339289 DOI: 10.1016/s0378-4347(01)00030-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A novel HPLC method with electrochemical detection is described for the determination of a growth-hormone-releasing hexapeptide (GHRP-6). HPLC conditions, such as the column, mobile phase, and oxidation potential, were optimized for sensitivity and selectivity of analysis. GHRP-6 was separated on a reversed-phase CN column with 37% acetonitrile in 100 mM phosphate buffer (pH 7.0) as the mobile phase. The optimum electrochemical oxidation signal was obtained at 0.85 V vs. Ag/AgCl in a glassy carbon working electrode due to two electroactive tryptophans and a histidine residue. Solid-phase extraction using octadecyl cartridges was optimized for sample cleanup of GHRP-6 from serum samples and the method was successfully applied over the concentration range of 5 to 100 ng/ml of analyte. reserved.
Collapse
|
584
|
Lee HS. [DNA chip data mining]. Exp Mol Med 2001; 33:151-6. [PMID: 11708322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
DNA chip data routinely contain gene expression levels of thousands of genes and the analysis should be supported by various computational tools. To be brief, the analysis procedure consists of four steps including image scanning, image processing, mathematical interpretation and biological interpretation. In image processing step, we should detect the spots and measure the signals of the spots and the background. In mathematical interpretation step, first of all we should massage the measured signals to make them appropriate for further mathematical analysis. The massaged data could be analyzed by various computational methods especially when the data were generated for multiple samples comparisons. The clustering techniques including hierarchical clustering, k-means clustering, SOTA, SOM are the most popular methods in this step. Various other multivariate statistics and related machine learning techniques are being introduced and applied to DNA chip data analysis recently. And finally the most important step we should tackle is the biological interpretation task. Although the depth of the domain knowledge about the biological situation under which the data were generated is the most important factor to elucidate the biological context, it could be supported by various bioinformatics tools including MEDLINE abstract processing by NLP techniques or genetic network models constructed by Boolean networks algorithms.
Collapse
|
585
|
Lee HS, LePlae PR, Porter EA, Gellman SH. An Efficient Route to Either Enantiomer of Orthogonally Protected trans-3-Aminopyrrolidine-4-carboxylic Acid. J Org Chem 2001; 66:3597-9. [PMID: 11348151 DOI: 10.1021/jo001534l] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
586
|
Na DH, Park MO, Choi SY, Kim YS, Lee SS, Yoo SD, Lee HS, Lee KC. Identification of the modifying sites of mono-PEGylated salmon calcitonins by capillary electrophoresis and MALDI-TOF mass spectrometry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 754:259-63. [PMID: 11318423 DOI: 10.1016/s0378-4347(00)00599-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A capillary electrophoretic method (CE) was developed for the determination of the PEG-modification sites of three positional isomers of mono-PEG modified salmon calcitonins (mono-PEG-sCTs). Resistance to proteolytic degradation on the PEG modification sites resulted in different patterns of CE electropherograms for the tryptic digested mono-PEG-sCTs isomers, and the PEG modification sites were assigned accordingly. The PEG-modification sites were also confirmed directly by determining the molecular masses of the tryptic digested PEG-modified fragments of respective mono-PEG-sCT by the matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry.
Collapse
|
587
|
Kang JL, Pack IS, Hong SM, Lee HS, Hah JS, Nam W, Leonard S, Castranova V. Zinc tetrakis(N-methyl-4'-pyridyl) porphyrinato is an effective inhibitor of stimulant-induced activation of RAW 264.7 cells. Toxicol Appl Pharmacol 2001; 172:140-9. [PMID: 11298500 DOI: 10.1006/taap.2001.9144] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
One proposed mechanism for the development of silica-induced fibrosis is prolonged pulmonary inflammation and lung damage resulting from the secretion of reactive mediators from alveolar macrophages. Metalloporphyrins have antioxidative and antiinflammatory activities. However, the molecular basis for the antiinflammatory action of zinc tetrakis(N-methyl-4'-pyridyl) porphyrinato (ZnTMPyP) has not been elucidated. The objective of this study was to determine whether ZnTMPyP exhibited the ability to inhibit the production of reactive oxygen species (ROS), the activation of NF-kappaB, or the secretion of IL-1 in RAW 264.7 cells, and whether such inhibitory activity was related to the ROS-scavenging ability of ZnTMPyP. The results indicate that, although ZnTMPyP is not cytotoxic to RAW 264.7 cells, it is a potent inhibitor in ROS production by RAW 264.7 cells in response to various stimulants, such as silica, zymosan, or phorbol myristate acetate. ZnTMPyP is also effective in reducing stimulant-induced DNA-binding activity of NF-kappaB and silica-induced tyrosine phosphorylation of IkappaB-alpha. ZnTMPyP also inhibits LPS-induced IL-1 production. However, ZnTMPyP exhibits relatively weak ability to directly scavenge hyroxyl or superoxide radicals. On the basis of effective concentrations of ZnTMPyP, these results suggest that ZnTMPyP directly acts as an inhibitor of cellular activation in addition to exhibiting an antioxidant effect. Therefore, it is suggested that further studies concerning the effects of ZnTMPyP using in vivo oxidative stress models or its effects on the cytotoxic process of human diseases associated with lung inflammation and injury are warranted. In addition, ZnTMPyP may be a useful tool to investigate the molecular mechanisms involved in stimulant-induced signal pathways.
Collapse
|
588
|
Woo DK, Kim HS, Lee HS, Kang YH, Yang HK, Kim WH. Altered expression and mutation of beta-catenin gene in gastric carcinomas and cell lines. Int J Cancer 2001. [PMID: 11241321 DOI: 10.1002/1097-0215(20010320)95:2<108::aid-ijc1019>3.0.co;2-#] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
beta-catenin serves not only as a structural component of the E-cadherin-mediated cell-cell adhesion system, but also as a signaling molecule of the Wnt/wingless pathway. Deregulated expression of beta-catenin and mutations of the gene have been identified in a number of human malignancies. To determine the role of beta-catenin defects in stomach cancer, we investigated beta-catenin exon 3 mutations and altered protein expression in 77 primary gastric carcinomas and 11 cell lines. In addition, the immunohistochemical expression pattern of beta-catenin in 303 consecutive gastric cancers was determined and their relationships with clinicopathologic features and patient outcome were investigated. This study revealed 5% (4 of 77) tumors and 27% (3 of 11) cell lines with beta-catenin gene alteration, 6 missense mutations, and 1 interstitial deletion. These genetic changes were shown to correlate closely with nuclear localization of the protein (p = 0.001). In an immunohistochemical analysis, abnormal expressions of beta-catenin, such as nuclear accumulation and loss of membranous distribution, were detected in 27% (81 of 303) of tumors overall. These altered beta-catenin expressions were more commonly observed in 37% (58 of 158) diffuse type gastric carcinomas (p < 0.001). Loss of membranous beta-catenin staining was associated with poor survival (p = 0.045). In conclusion, our results demonstrate that beta-catenin mutations are common in gastric cancer cell lines but occur infrequently in gastric carcinoma tissues. These mutations are one of the causes of the nuclear accumulation of beta-catenin. Frequent abnormalities of beta-catenin expression in gastric carcinoma support the idea that both structural and signaling functions of the protein play a critical role in gastric carcinogenesis.
Collapse
|
589
|
Kim SJ, Ha J, Jung IM, Ahn MS, Kim M, Lee HS, Cheong HI, Choi Y. Recurrent focal segmental glomerulosclerosis following renal transplantation in Korean pediatric patients. Pediatr Transplant 2001; 5:105-11. [PMID: 11328548 DOI: 10.1034/j.1399-3046.2001.005002105.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The recurrence of focal segmental glomerulosclerosis (FSGS) in transplants is a well-known problem in pediatric renal transplantation (Tx). Recently, the race of the recipient was recognized as a major variable associated with disease recurrence. In view of this finding, we report on our single-center experience of FSGS recurrence in Korean children, an ethnically homogeneous Far East Asian population. Clinical records and renal biopsy specimens, both native and graft, were reviewed for all pediatric renal Txs (recipient age < or = 18 yr) performed at Seoul National University Hospital from 1984 to 1999. Twenty-two children with primary FSGS received 22 allografts for renal replacement. The mean age of disease onset in these patients was 5.9 yr. The grafts were from 12 living-related, six living-unrelated, and four cadaveric donors, and all recipients were immunosuppressed with cyclosporin A (CsA)-based regimens. Post-transplant recurrence of FSGS was confirmed in nine patients (41%). Long-term graft survival in recurrent and non-recurrent groups was not significantly different. Risk factor analysis showed that patients with a disease duration shorter than 48 months (odds ratio 11.7, 95% CI 1.53-89.1) and a glomerulosclerosis percentage of < 55% by renal biopsy (odds ratio 16.0, 95% CI 1.45-176) were at greater risk of disease recurrence. These results suggest that Korean children are similar to non-African-American youngsters in the USA and Europe with respect to post-transplant recurrence of FSGS. The same may be true of other Far Eastern Asian children.
Collapse
|
590
|
Ku SK, Lee HS, Park KD, Lee JH. An immunohistochemical study on the pancreatic islets cells of the Mongolian gerbils, Meriones unguiculatus. J Vet Sci 2001; 2:9-14. [PMID: 14614288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023] Open
Abstract
In order to study the regional distribution and relative frequency of the immunoreactive endocrine cells in the pancreatic islets of the Mongolian gerbil, pancreatic sections of Meriones unguiculatus were immunostained using an immunohistochemical (PAP) method with four types of specific antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (PP). The pancreatic islets were subdivided into three portions (central region, mantle zone and peripheral region) according to their composition of immunoreactive cells. Spherical to spindle shaped insulin, glucagon, somatostatin and PP-immunoreactive cells were observed in this study. Insulin-immunoreactive cells were present in the central regions with high frequency, and a few of these cells were also demonstrated in the mantle zones. Glucagon-immunoreactive cells were mainly restricted to the mantle zones. However, rare examples were found in the peripheral regions. As for the glucagon-immunoreactive cells, somatostatin-immunoreactive cells were detected in the mantle zones and peripheral regions with moderate and rare frequencies, respectively. PP-immunoreactive cells were found in the mantle zones and peripheral regions with rare and moderate frequencies, respectively. In the mantle and the peripheral regions, cytoplasmic process of glucagon-, somatostatin- and PP-immunoreactive cells were intermingled. In conclusion, the regional distribution of endocrine cells in the pancreatic islets of Mongolian gerbil was found to be similar to that of other mammals, especially other rodents, except for the topographical different distribution of somatostatin which differs that of other rodents.
Collapse
|
591
|
Lee SJ, Song CW, Jeen YT, Chun HJ, Lee HS, Um SH, Lee SW, Choi JH, Kim CD, Ryu HS, Hyun JH. Prevalence of endoscopic reflux esophagitis among Koreans. J Gastroenterol Hepatol 2001; 16:373-6. [PMID: 11354273 DOI: 10.1046/j.1440-1746.2001.02464.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND AIM Although reflux esophagitis is believed to be common in the Western population, very few epidemiologic data on reflux esophagitis in Koreans are available. The aims of this study were to evaluate the prevalence of endoscopic reflux esophagitis in patients who came for a physical check-up at Korea University Hospital, and to study the relationship between various factors relevant to reflux disease. METHODS This study was carried out prospectively on 7,015 patients who received an esophagogastroduodenoscopy from September 1996 to December 1997. Most of the patients were free of symptoms and had come for their self-paid check-up. RESULTS The overall prevalence of reflux esophagitis was 3.4%, and most of the patients had a mild degree of esophagitis representing grade 1 in 98.3% and grade 2 in 1.7%. The male: female ratio for esophagitis was 7 : 1, and the body mass index (BMI) was significantly higher in patients with reflux esophagitis. A hiatal hernia was found in 166 patients with esophagitis (68.6%), but only in 9.2% patients without esophagitis (P < 0.05). Smoking and alcohol consumption were associated with the development of reflux esophagitis (P < 0.05). CONCLUSIONS The prevalence of endoscopic reflux esophagitis among Koreans is 3.4%, and most of the patients had a mild grade esophagitis. Smoking, alcohol consumption, the presence of a hiatal hernia and a higher BMI are associated with the development of reflux esophagitis.
Collapse
|
592
|
Lee HS, Castle WS, Coates GA. High-performance liquid chromatography for the characterization of carotenoids in the new sweet orange (Earlygold) grown in Florida, USA. J Chromatogr A 2001; 913:371-7. [PMID: 11355835 DOI: 10.1016/s0021-9673(00)01029-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
High-performance liquid chromatography with photodiode array detection was developed for the separation and identification of carotenoids from a new sweet orange, Earlygold. Carotenoid pigments were extracted using hexane-acetone-ethanol and saponified using 10% methanolic potassium hydroxide. More than 25 carotenoid pigments were separated within 40 min using a ternary gradient (acetonitrile-methanol, methyl tert-butyl ether and water) elution on a C30 reversed-phase column. The carotenoid pattern of Earlygold was generally similar to the early season Hamlin but with some quantitative differences, especially with violaxanthin. Major carotenoids including violaxanthin, lutein, beta-cryptoxanthin, antheraxanthin, luteoxanthin, zeaxanthin, beta-carotene, and alpha-carotene were identified based on on-line spectral data obtained by a photodiode array detector, and comparison to the spectra of the standards and reported values. A numerical notation, the ratio of the peak heights between absorption bands, was also calculated to compare to the literature values.
Collapse
|
593
|
Kim IW, Lee HS, Lee YK, Jang MD, Par JH. Selectivity of amino-, cyano- and diol-bonded silica in reversed-phase liquid chromatography. J Chromatogr A 2001; 915:35-42. [PMID: 11358260 DOI: 10.1016/s0021-9673(01)00628-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Amino-, cyano- and diol-bonded silica stationary phases were characterized by estimating their characteristic interaction constants in reversed-phase liquid chromatography (RPLC) based on linear solvation energy relationships. Five characteristic interaction constants of the stationary phases, the hydrophobicity (v), polarizability (r), dipolarity (s), hydrogen bond (HB) acceptor basicity (a) and HB donor acidity strength (b) were determined by multiple regression analyses of logarithmic retention factors (k) for a set of test solutes measured on them in 10% (v/v) methanol-water vs. the solute properties represented by characteristic molecular volume (Vx), excess polarization (R2), dipolarity/polarizability (pi*), HB donor acidity (alpha) and HB acceptor basicity (beta). Magnitudes of the five constants for the phases in RPLC were compared with those in normal-phase LC to see the differences in chromatographic selectivity in the two LC modes.
Collapse
|
594
|
Lee YW, Kang IH, Kim SM, Lee HL, Koo TW, Lee HS, Hwang JJ. Population genetics of the hypervariable locus D12S391 in Koreans. Int J Legal Med 2001; 114:118-21. [PMID: 11197617 DOI: 10.1007/s004140000132] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The hypervariable short tandem repeat (STR) locus D12S391 was investigated in a Korean population and 34 fragments were sequenced to confirm the structure of alleles. From these sequenced fragments an allelic ladder containing 13 sequenced alleles was constructed. From 595 unrelated Koreans, 14 alleles were detected and one variant allele 19.3 was observed. The observed heterozygosity was 0.795 and no deviation from Hardy-Weinberg equilibrium was observed in the Korean population (p = 0.606). The allele frequency distribution in the Korean population was not similar to other racial or ethnic groups except for Egyptians, Yemenis, Japanese and Caucasoids from the Rhine area. No mutations were observed in the 702 meioses from 144 Korean families. This study demonstrates that the STR locus D12S391 is a useful tool for forensic identification and parentage testing.
Collapse
|
595
|
Han GR, Lee YW, Lee HL, Kim SM, Ku TW, Kang IH, Lee HS, Hwang JJ. A Korean population study of the nine STR loci FGA, VWA, D3S1358, D18S51, D21S11, D8S1179, D7S820, D13S317 and D5S818. Int J Legal Med 2001; 114:41-4. [PMID: 11197626 DOI: 10.1007/s004140000137] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
DNA typing was performed on 379 randomly selected unrelated Koreans using the nine short tandem repeat loci FGA, VWA, D3S1358, D18S51, D21S11, D8S1179, D7S820, D13S317 and D5S818 present in the AmpF/STR Profiler Plus PCR amplification kit. Allele frequencies, heterozygosity, power of discrimination, mean exclusion chance, and polymorphism information content of each locus were calculated by statistical analysis. All nine loci were in Hardy-Weinberg equilibrium. The combined discrimination index and the combined mean exclusion chance in Koreans was 2.31 x 10(-12) and 0.99983, respectively. By evaluation of 297 children from 128 families, 2 mutations were found at the FGA locus and 1 each at the D18S51 and D13S317 loci. This study demonstrates that this multiplex system is a useful and convenient tool for forensic identification and parentage testing in Korea.
Collapse
|
596
|
Chen CH, Chen GJ, Lee HS, Huang GT, Yang PM, Tsai LJ, Chen DS, Sheu JC. Expressions of cancer-testis antigens in human hepatocellular carcinomas. Cancer Lett 2001; 164:189-95. [PMID: 11179834 DOI: 10.1016/s0304-3835(01)00379-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Though regular sonographic examination can early detect small hepatocellular carcinoma, the therapeutic results remains unsatisfactory. Antigen-specific immunotherapy is an alternative approach for controlling tumors. The prerequisite for antigen-specific cancer immunotherapy is the identification of appropriate tumor antigens. Recently, a new category of tumor-specific shared antigens, called cancer-testis antigens, has been identified. The cancer-testis antigens have been found in a variety of cancers. However, the expression of cancer-testis antigens in human hepatocellular carcinomas is unknown. The aim of this current study is to investigate the expression of cancer-testis antigens in human hepatocellular carcinomas. Reverse-transcription polymerase chain reaction (RT-PCR) was used to investigate the expression of the SSX-1,-2,-4,-5, SCP-1, NY-ESO-1 genes in tumorous and corresponding non-tumorous liver tissues. In the 30 hepatocellular carcinomas studied, SSX-1,-2,-4,-5, SCP-1, and NY-ESO-1 mRNA expressions were detected in 24 (80%), 14 (46.7%), 22 (73.3%), 10 (33.3%), 2 (6.7%), and 11 (36.7%), respectively. Expressions of these genes were detected in few non-tumor liver tissues. The cancer-testis antigens are expressed in a high percentage of hepatocellular carcinomas. These cancer-testis antigen gene products are potential targets for antigen-specific immunotherapy of hepatocellular carcinoma.
Collapse
|
597
|
Woo DK, Kim HS, Lee HS, Kang YH, Yang HK, Kim WH. Altered expression and mutation of beta-catenin gene in gastric carcinomas and cell lines. Int J Cancer 2001; 95:108-13. [PMID: 11241321 DOI: 10.1002/1097-0215(20010320)95:2<108::aid-ijc1019>3.0.co;2-#] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
beta-catenin serves not only as a structural component of the E-cadherin-mediated cell-cell adhesion system, but also as a signaling molecule of the Wnt/wingless pathway. Deregulated expression of beta-catenin and mutations of the gene have been identified in a number of human malignancies. To determine the role of beta-catenin defects in stomach cancer, we investigated beta-catenin exon 3 mutations and altered protein expression in 77 primary gastric carcinomas and 11 cell lines. In addition, the immunohistochemical expression pattern of beta-catenin in 303 consecutive gastric cancers was determined and their relationships with clinicopathologic features and patient outcome were investigated. This study revealed 5% (4 of 77) tumors and 27% (3 of 11) cell lines with beta-catenin gene alteration, 6 missense mutations, and 1 interstitial deletion. These genetic changes were shown to correlate closely with nuclear localization of the protein (p = 0.001). In an immunohistochemical analysis, abnormal expressions of beta-catenin, such as nuclear accumulation and loss of membranous distribution, were detected in 27% (81 of 303) of tumors overall. These altered beta-catenin expressions were more commonly observed in 37% (58 of 158) diffuse type gastric carcinomas (p < 0.001). Loss of membranous beta-catenin staining was associated with poor survival (p = 0.045). In conclusion, our results demonstrate that beta-catenin mutations are common in gastric cancer cell lines but occur infrequently in gastric carcinoma tissues. These mutations are one of the causes of the nuclear accumulation of beta-catenin. Frequent abnormalities of beta-catenin expression in gastric carcinoma support the idea that both structural and signaling functions of the protein play a critical role in gastric carcinogenesis.
Collapse
|
598
|
Jeong CK, Lee HY, Jang MS, Kim WB, Lee HS. Narrowbore high-performance liquid chromatography for the simultaneous determination of sildenafil and its metabolite UK-103,320 in human plasma using column switching. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 752:141-7. [PMID: 11254188 DOI: 10.1016/s0378-4347(00)00536-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A fully automated narrowbore high-performance liquid chromatography method with column switching was developed for the simultaneous determination of sildenafil and its active metabolite UK-103,320 in human plasma samples without pre-purification. Diluted plasma sample (100 microl) was directly introduced onto a Capcell Pak MF Ph-1 column (20x4 mm I.D.) where primary separation occurred to remove proteins and concentrate target substances using 15% acetonitrile in 20 mM phosphate solution (pH 7). The drug molecules eluted from the MF Ph-1 column were focused in an intermediate column (35x2 mm I.D.) by a valve switching step. The substances enriched in the intermediate column were eluted and separated on a phenyl-hexyl column (100x2 mm I.D.) using 36% acetonitrile in 10 mM phosphate solution (pH 4.5) when the valve status was switched back. The method showed excellent sensitivity (detection limit of 10 ng/ml), good precision (RSD < or = 2.3%) and accuracy (bias: +/-2.0%) and speed (total analysis time 17 min). The response was linear (r2 > or = 0.999) over the concentration range 10-1000 ng/ml.
Collapse
|
599
|
Lee HS, Gilliland SE, Carter S. Amylolytic Cultures of Lactobacillus acidophilus : Potential Probiotics to Improve Dietary Starch Utilization. J Food Sci 2001. [DOI: 10.1111/j.1365-2621.2001.tb11343.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
600
|
Song SY, Chung JW, Han JK, Lim HG, Koh YH, Park JH, Lee HS, Kim CY. Liver abscess after transcatheter oily chemoembolization for hepatic tumors: incidence, predisposing factors, and clinical outcome. J Vasc Interv Radiol 2001; 12:313-20. [PMID: 11287508 DOI: 10.1016/s1051-0443(07)61910-1] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
PURPOSE To evaluate the incidence of, predisposing factors for, and clinical outcome of liver abscess developing in patients with hepatic tumors after transcatheter oily chemoembolization (TOCE). MATERIALS AND METHODS During the past 6-year period, 2,439 patients with hepatic tumors underwent a total of 6,255 TOCE procedures. With a retrospective review of medical records, the authors evaluated the occurrence of liver abscess, the statistical significance of potential predisposing factors including portal vein obstruction, metastatic tumors, biliary abnormalities (type 1, simple biliary obstruction; type 2, status prone to ascending biliary infection), malignant gastrointestinal mucosal lesions, and additional gelatin sponge particle embolization in liver abscess formation, and the clinical outcome of abscess. RESULTS Fifteen liver abscesses occurred in 14 patients (0.2%). Liver abscesses developed in three of 987 (0.3%) TOCE procedures for portal vein obstruction, three of 114 (2.6%) procedures for metastatic tumors, one of 49 (1.8%) for type 1 biliary abnormality, four of 55 (7.4%) for type 2 biliary abnormality, two of 18 (11.1%) for malignant gastrointestinal mucosal lesion, and nine of 2,108 (0.4%) for additional gelatin sponge particle embolization. Univariate and multivariate statistical analysis showed that type 2 biliary abnormality was a significant predisposing factor. The mortality related to liver abscess occurred in two patients (13.3%). Thirteen liver abscesses were successfully treated with parenteral antibiotics and percutaneous catheter drainage. However, irreversible deterioration of liver function occurred in two patients. Two of nine further TOCE procedures in three patients caused recurrent septicemia and liver abscess. CONCLUSION The biliary abnormality prone to ascending biliary infection was the most important predisposing factor to the development of liver abscess after TOCE. Postembolic liver abscess could be effectively managed with percutaneous catheter drainage.
Collapse
|