351
|
Lee HT, Lee YJ, Chung SJ, Shim CK. Effect of prokinetic agents, cisapride and metoclopramide, on the bioavailability in humans and intestinal permeability in rats of ranitidine, and intestinal charcoal transit in rats. RESEARCH COMMUNICATIONS IN MOLECULAR PATHOLOGY AND PHARMACOLOGY 2000; 108:311-23. [PMID: 11958284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
To investigate the effect of two prokinetic drugs, cisapride and metoclopramide, on the bioavailability of drugs, a marker drug, ranitidine, was administered to healthy volunteers following pre-treatments with or without the prokinetic agents. Cisapride or metoclopramide HCl (a respective dose of 10 mg) was administered orally 30 min prior to an oral administration of ranitidine (300 mg). Serum samples were collected for a 12 h period after the administration of ranitidine and the concentration of ranitidine was determined by an HPLC method. The bioavailability parameters of the groups with the prokinetic agent pretreatment were compared with those of the control group. In addition, the effects of these prokinetic drugs on the in vitro apparent permeability of ranitidine across the rat jejunum in the Ussing chamber, and on the in vivo intestinal transit of charcoal meals in rats were also examined. The Tmax of ranitidine in human subjects was shortened significantly by the either of the pretreatments (i.e., with cisapride and metoclopramide). The AUC(inf) of ranitidine in human subjects was also decreased significantly in the case of cisapride pretreatment. However, no changes were observed for the values of Cmax and T(1/2) by the pretreatments. Rat studies revealed that cisapride and metoclopramide had no influence on the in vitro permeability of ranitidine or the in vivo intestinal transit of charcoal meals. Therefore, these data indicated that the changes in the bioavailability parameters (i.e., Tmax and AUC(inf)) in humans are not related with the intestinal permeability or intestinal transit of ranitidine. The shortened Tmax of ranitidine appears to be due to accelerated gastric emptying of the drug. However, underlying mechanisms for the decreased AUC(inf) of ranitidine in the case of cisapride pretreatment are currently unclear.
Collapse
|
352
|
Cho HR, Choi DH, Ko BK, Nam CW, Park KM, Lee YJ, Lee SG, Lee JS, Lee KA, Lee EA, Ju SA, Kim BS. Cold preservation of rat cultured hepatocytes: the scoparone effect. Transplant Proc 2000; 32:2325-7. [PMID: 11120185 DOI: 10.1016/s0041-1345(00)01684-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
353
|
Lee YJ. Growth hormone therapy in Turner syndrome. ACTA PAEDIATRICA TAIWANICA = TAIWAN ER KE YI XUE HUI ZA ZHI 2000; 41:292-3. [PMID: 11198933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
|
354
|
Park JH, Choi EA, Cho EW, Lee YJ, Park JM, Na SY, Kim KL. Detection of cellular receptors specific for the hepatitis B virus preS surface protein on cell lines of extrahepatic origin. Biochem Biophys Res Commun 2000; 277:246-54. [PMID: 11027670 DOI: 10.1006/bbrc.2000.3661] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Hepatitis B virus infection is primarily mediated by the interaction of the preS region of the viral envelope protein with its still unknown cellular receptor. Using recombinantly expressed preS proteins, the distribution of preS-binding receptors on cell lines from extrahepatic origins was determined by immunofluorescence and flow cytometry. In contrast to human liver cell lines, most cell lines from extrahepatic origins did not bind preS proteins. Nevertheless, exceptions were found in the bone marrow-derived cell line, KG-1, and the osteogenic sarcoma cell line SaOS-2, as well as in the previously reported EBV-transformed B-cell line, Wa. To determine the biochemical nature of these receptors, Wa-cells were cell surface biotinylated and the preS-binding receptors were isolated by immunoprecipitation. A specific band with a molecular weight of approximately 30 kDa was identified in a SDS-polyacrylamide gel, which further characterization is expected to provide clues regarding the infection mechanism of HBV in hepatic- and extra-hepatic cells.
Collapse
|
355
|
Lee SG, Lee YJ, Park KM, Hwang S, Min PC. One hundred and eleven liver resections for hilar bile duct cancer. JOURNAL OF HEPATO-BILIARY-PANCREATIC SURGERY 2000; 7:135-41. [PMID: 10982605 DOI: 10.1007/s005340050167] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A positive correlation between absence of residual tumor at resection margins and long-term survival in the treatment of hilar bile duct carcinoma has encouraged some surgeons to use a more radical approach, including liver/portal vein resection and combined pancreatoduodenectomy. However, if liver resection is associated with significant morbidity and mortality, it may not produce any overall benefit. This review was undertaken in an attempt to determine whether liver resection is a safe procedure and whether if has any beneficial effect over that of local bile duct excision alone, in terms of achieving curative resection and long-term survival. The records of 151 patients with hilar bile duct carcinoma surgically treated between June 1989 and December 1997 at the Asan Medical Center, Seoul, were retrospectively analyzed. Surgical resection was possible in 128 patients. The remaining 23 patients had surgical palliative drainage. Local bile duct excision alone was performed in 17 patients. Liver resection for tumor extending to secondary bile ducts or hepatic parenchyma was performed in 111 patients; portal vein resection was necessary in 29 of these 111 patients (26.1%) and pancreatoduodenectomy was combined in 18 patients (16.2%). Seven patients died during hospitalization after liver resection, an operative mortality of 6.3%. Margins of bile duct resection were free of tumor on histologic examination in 4 of the 17 local bile duct excisions, but in 86 of the 111 liver resections. The cumulative survival rate after local bile duct excision was 85.7% at 1 year, 42.9% at 2 years, 21.4% at 3 years, and 0% at 4 years. However, the survival rate after liver resection (excluding operative mortality) was 97.1% at 1 year, 72.8% at 2 years, 55.3% at 3 years, and 24.0% at 5 years. Survival and the percentage of patients with tumor-free resection margins after liver resection were superior to those after local bile duct excision. Resection of hilar bile duct carcinoma offers long-term survival only when surgery is aggressive and includes liver resection.
Collapse
|
356
|
Huang Y, Lee YJ, Chen MR, Hsu CH, Lin SP, Sung TC, Chang SC, Chang JG. Polymorphism of transmembrane region of MICA gene and Kawasaki disease. EXPERIMENTAL AND CLINICAL IMMUNOGENETICS 2000; 17:130-7. [PMID: 10899738 DOI: 10.1159/000019132] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Kawasaki disease is a febrile disease of children complicated with vasculitis of the coronary arteries and potential aneurysm formation. It has been recognized worldwide and appears to be increasing in frequency. Studies have found that Kawasaki disease is associated with major histocompatibility complex (MHC) class I B antigens. The MHC-class-I-chain-related gene A (MICA) is located near HLA-B. It has a triplet repeat microsatellite polymorphism in the transmembrane region. We investigated the microsatellite polymorphism in children with Kawasaki disease and controls. Seventy children (46 boys), age at diagnosis 1.68 +/- 1.69 years, with Kawasaki who were treated with aspirin as well as intravenous gamma-globulin were enrolled. Control subjects consisted of 154 children (87 boys), age 2.81 +/- 2.12 years. Phenotype frequency of allele A4 in patients with aneurysm formation was significantly lower than in patients without aneurysms [relative risk (RR) = 0.06, 95% confidence interval (CI) = 0.01-0.48, p = 0.00469, pc = 0.0232] and showed a similar tendency when compared with controls. Gene frequency of allele A4 was also significantly lower in patients who developed aneurysms than in patients who did not (RR = 0.07, 95% CI = 0.01-0.57, p = 0.0057, pc = 0.0282). Gene frequency of allele A5 showed a tendency to be higher in patients who developed aneurysms than in controls (RR = 2.35, 95% CI = 0.98-5.63, p = 0.0486, pc = 0. 220). Allele A5.1 tended to be negatively associated with Kawasaki disease (RR = 0.57, 95% CI = 0.35-0.93, p = 0.022, pc = 0.105). Our study showed that allele A4 was negatively associated with coronary aneurysm formation in Kawasaki disease. This suggests that allele A4 protects the children with Kawasaki disease from developing coronary aneurysms after aspirin and gamma globulin therapy.
Collapse
|
357
|
Sim KB, Cho BK, Lee YJ, Lee MS, Wang KC. Chronological changes of re-closure capacity in surgically induced spinal open neural tube defects of chick embryos. Neurosci Lett 2000; 292:151-4. [PMID: 11018299 DOI: 10.1016/s0304-3940(00)01435-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
To investigate the re-closure capacity of surgically induced spinal open neural tube defects (ONTD) and its correlation to the cell proliferation activity in embryonic stages, longitudinal incisions of 3- or 6-somite lengths were made in neural tubes of chick embryos at Hamburger and Hamilton stage 18-19, and the length of the ONTDs was measured on postoperative days 2, 3, 5, 7, and 10. The results demonstrated that re-closure occurred more actively when the incision length was shorter. The chronological changes in the re-closure capacity of the ONTDs paralleled the proliferative activity of the neural tube. We conclude that surgically induced spinal ONTDs may be remodeled in early chick embryos and that manipulation of cell dynamics can enhance the re-closure process in the embryonic spinal cord tissue.
Collapse
|
358
|
Lee SG, Lee YJ, Park KM, Hwang S, Min PC. One hundred and eleven liver resections for hilar bile duct cancer. JOURNAL OF HEPATO-BILIARY-PANCREATIC SURGERY 2000. [PMID: 10982605 DOI: 10.1007/s005340000070135.534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A positive correlation between absence of residual tumor at resection margins and long-term survival in the treatment of hilar bile duct carcinoma has encouraged some surgeons to use a more radical approach, including liver/portal vein resection and combined pancreatoduodenectomy. However, if liver resection is associated with significant morbidity and mortality, it may not produce any overall benefit. This review was undertaken in an attempt to determine whether liver resection is a safe procedure and whether if has any beneficial effect over that of local bile duct excision alone, in terms of achieving curative resection and long-term survival. The records of 151 patients with hilar bile duct carcinoma surgically treated between June 1989 and December 1997 at the Asan Medical Center, Seoul, were retrospectively analyzed. Surgical resection was possible in 128 patients. The remaining 23 patients had surgical palliative drainage. Local bile duct excision alone was performed in 17 patients. Liver resection for tumor extending to secondary bile ducts or hepatic parenchyma was performed in 111 patients; portal vein resection was necessary in 29 of these 111 patients (26.1%) and pancreatoduodenectomy was combined in 18 patients (16.2%). Seven patients died during hospitalization after liver resection, an operative mortality of 6.3%. Margins of bile duct resection were free of tumor on histologic examination in 4 of the 17 local bile duct excisions, but in 86 of the 111 liver resections. The cumulative survival rate after local bile duct excision was 85.7% at 1 year, 42.9% at 2 years, 21.4% at 3 years, and 0% at 4 years. However, the survival rate after liver resection (excluding operative mortality) was 97.1% at 1 year, 72.8% at 2 years, 55.3% at 3 years, and 24.0% at 5 years. Survival and the percentage of patients with tumor-free resection margins after liver resection were superior to those after local bile duct excision. Resection of hilar bile duct carcinoma offers long-term survival only when surgery is aggressive and includes liver resection.
Collapse
|
359
|
Huang FY, Lee YJ, Lo FS, Wang CH, Lin SP, Hsu CH, Kao HA, Tsan KW, Chang JG. DQA1*Arg52,DQB1*nonAsp57, and DRB1*04 genotypes in Chinese children with insulin-dependent diabetes mellitus. EXPERIMENTAL AND CLINICAL IMMUNOGENETICS 2000; 15:33-45. [PMID: 9619398 DOI: 10.1159/000019051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ethnic comparisons are extremely important and useful for studying the HLA component involved in insulin-dependent diabetes mellitus (IDDM) predisposition. To date there have been only a few reports on the association of HLA loci and IDDM in Chinese. We report here a study on DQA1*Arg52, DQB1*nonAsp57, and DRB1*04 in IDDM children and control adults among Han Chinese living in Taiwan. One hundred and fourteen unrelated children (62 boys) with IDDM were studied. Their ages at diagnosis were between 0.3 and 15.0 years (6.8 +/- 3.6 years). The control population consisted of 120 randomly selected normal adults. DQA1*Arg52(+/+), DQB1*nonAsp57(+/+), and DRB1*04(+/-) were associated with IDDM (RR = 11.50, 2.21, and 2.82; p = 1.11 x 10(-15), 2.84 x 10(-3), and 1.98 x 10(-4), respectively). DQA1*Arg52, DQB1*nonAsp57, and DRB1*04 conferred risks for IDDM (RR = 12.79, 7.11, and 2.83; pc = 8.22 x 10(-4), 5.35 x 10(-3), and 5.68 x 10(-4), respectively). Combinations of DQA1*Arg52 and DRB1*04 conferred the highest risk for IDDM (RR = 19.64, pc = 5.4 x 10(-5)). DQA1*Arg52 was associated with IDDM in subjects with DQB1*nonAsp57+ (RR = 14.87, pc = 2.41 x 10(-4)) and DQB1*nonAsp57 was also associated with IDDM in subjects with DQA1*Arg52+ (RR = 8.41, pc = 1.54 x 10(-3)), suggesting that DQA1*Arg52 and DQB1*nonAsp57 are interacting. This study demonstrates that DQA1*Arg52, DQB1*nonAsp57, and DRB1*04 confer susceptibility for IDDM to Chinese children. A combination of DQA1*Arg52 and DRB1*04 confers the highest risk and it is suggested that a susceptibility gene might be situated between DQA1*Arg52 and DRB1*04 or both are synergistic. There is an interaction between DQA1*Arg52 and DQB1*nonAsp57 and homozygosity for DQA1*Arg52/DQB1*nonAsp57, which encodes four susceptibility DQ heterodimers, confers a high risk.
Collapse
|
360
|
Abstract
Oxidants such as H(2)O(2) can induce a low level of apoptosis at low concentrations but at higher concentrations cause necrosis. Higher concentrations of H(2)O(2) also inhibit the induction of apoptosis by chemotherapy drugs. One theory is that, at higher concentrations, H(2)O(2) causes direct oxidative inactivation of caspase-3 activity, thus preventing the apoptotic pathway from being used. We find that treatment of recombinant caspase-3 with H(2)O(2) can partially reduce its enzymatic activity: However, the following findings show that this does not occur in the cell. (1) The inhibition by H(2)O(2) of VP-16-induced apoptosis and cellular caspase-3 activity can be overcome by adding inhibitors of poly(ADP-ribose) polymerase (PARP) at sub-stoichiometric concentrations. (2) Delayed addition of H(2)O(2) to VP-16-treated cells prevents additional caspase induction but does not inhibit the caspase activity that has already been generated. (3) H(2)O(2) is a poor inhibitor of caspase-3 activity in cell lysates. (4) Addition of H(2)O(2) to cells inhibits activation of caspase-9, which is required for activation of caspase-3. We conclude that inhibition of caspase-3 activity in the cell occurs indirectly at a step located upstream of caspase-3 activation. H(2)O(2) acts in part by inducing DNA strand breaks and activating PARP, thus depleting the cells of ATP. When this pathway is blocked, even high concentrations of H(2)O(2) can induce caspase-9 and -3 activation and cause apoptosis.
Collapse
|
361
|
Park SH, Cho HN, Lee SJ, Kim TH, Lee Y, Park YM, Lee YJ, Cho CK, Yoo SY, Lee YS. Hsp25-induced radioresistance is associated with reduction of death by apoptosis: involvement of Bcl2 and the cell cycle. Radiat Res 2000; 154:421-8. [PMID: 11023606 DOI: 10.1667/0033-7587(2000)154[0421:hiriaw]2.0.co;2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We previously demonstrated the protective effect of the small heat-shock protein against oxidative damage induced by tumor necrosis factor alpha. Here we have extended our studies of the possible role of Hsp25 in ionizing radiation-induced damage. For these studies, we transfected murine fibroblast L929 cells with the Hsp25 gene and selected three stably transfected clones. Hsp25 overexpression conferred radioresistance as detected by clonogenic survival and induction of apoptosis. Interestingly, the Hsp25-transfected cells showed an increase in the level of the anti-apoptosis molecule Bcl2. We also observed alterations of cell growth in the Hsp25-transfected cells. The cell cycle time of Hsp25-transfected cells was 3-4 h slower than that of vector-transfected control cells. Flow cytometry analysis of synchronized cells at late G(1) phase by mimosine treatment also showed the growth delay in Hsp25-overexpressing cells. In addition, reduced cyclin D1, cyclin A and Cdc2 levels and increased levels of Cdkn1a (also known as p21(Waf)) were observed in Hsp25-transfected cells, which probably caused the reduction in cell growth. In addition, synchronization by mimosine treatment only partially altered radioresistance in the Hsp25-transfected cells. Taken together, these data suggest that Hsp25-induced radioresistance is associated with growth delay as well as induction of Bcl2.
Collapse
|
362
|
Kim YG, Lee YJ, Lee ED, Lee SD, Kwon JW, Kim WB, Shim CK, Lee MG. Bioequivalence assessment of closerin capsule to dura seromycin capsule of cycloserine after a single oral dose administration to healthy male volunteers. Int J Clin Pharmacol Ther 2000; 38:461-6. [PMID: 11073286 DOI: 10.5414/cpp38461] [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: 11/18/2022] Open
Abstract
AIM A bioequivalence study of the closerin capsules to the dura seromycin capsules was conducted. PATIENTS AND METHODS Twenty-four healthy male Korean volunteers received each medicine at the cycloserine dose of 250 mg in a 2 x 2 crossover study. There was a one-week washout period between the doses. Plasma concentrations of cycloserine were monitored by a high-performance liquid chromatography for over a period of 72 hours after the administration. AUCinf (the area under the plasma concentration-time curve from time zero to time infinity) was calculated by the linear-log trapezoidal method. Cmax (maximum plasma drug concentration) and Tmax (time to reach Cmax) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed AUCinf and Cmax, and untransformed Tmax. RESULTS There were no significant differences between the medications in AUCinf and Cmax. The point estimates and 90% confidence intervals for AUCinf (parametric) and Cmax (parametric) were, in point estimate (90% confidence interval), 0.992 (0.950 approximately 1.037) and 1.051 (0.965 approximatly 1.144), respectively, satisfying the bioequivalence criteria of the European Committee for Proprietary Medicinal Products and the US Food and Drug Administration Guidelines. The corresponding value of Tmax was 0.000 (-0.250 approximatly 0.125). Moreover, the modified Pitman-Morgan's adjusted F test and equal variance test (one-sided) indicated that the 2 medications were comparable in intra- and inter-individual variability in cycloserine bioavailability. CONCLUSION Therefore, these results indicate that the 2 medications of cycloserine are bioequivalent and, thus, may be prescribed interchangeably.
Collapse
|
363
|
Cheng CH, Chen MY, Lee YJ, Lee MC, Shu KH, Wu MY, Lian JD. Assessment of nutritional status in continuous ambulatory peritoneal dialysis patients: a comparison of bioelectric impedance and conventional methods. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 2000; 63:758-64. [PMID: 11076433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
BACKGROUND Nutritional status is an important factor in long term continuous ambulatory peritoneal dialysis (CAPD) prognoses. Conventionally, serum albumin is an indicator of nutritional status. More recently, protein catabolic rate and lean body mass have been calculated during peritoneal equilibrium testing to assess nutritional status. These have the advantage of providing an early indication of malnutrition before the serum albumin decreases. Bioelectric impedance analysis (BIA) of nutrition has the advantage of being the simplest procedure among all nutritional assessments. Standard nutritional assessments was compared with the BIA method. METHODS The protein catabolic rate and lean body mass was measured by the Keshaviah method. At the same time BIA was used to assess lean body mass, fat mass and fixed percentage of fat in 27 long-term CAPD patients, with and without peritoneal fluids. RESULTS Among the 27 patients, the protein catabolic rate was 0.95+/-0.5 g/kg/day and lean body mass was 37.4+/-0.5 kg measured by the conventional method. Using BIA, the lean body mass was 37.8+/-11.0 kg with peritoneal dialysate, which was strongly correlated with the conventional method (p<0.001). BIA of lean body mass was 37.4+/-9.2 kg without peritoneal dialysate, which was also significantly correlated to the conventional method (p<0.001). CONCLUSIONS BIA nutritional assessment of lean body mass was comparable to the conventional method of nutritional assessment. The presence or absence of peritoneal dialysate did not influence the BIA method for detection of lean body mass. BIA has the advantage of being a more simple procedure and can be used for the long-term assessment of nutritional status in CAPD patients.
Collapse
|
364
|
Abstract
The genomic organization of rat urocortin was determined using both cDNA and liver genomic DNA as templates for polymerase chain reactions. A single intron of 261 bp was found upstream to the ATG start codon, and the whole urocortin coding sequence was shown to be contained in a single exon. Relying on these results, oligonucleotide primers were designed, which can differentiate genomic DNA contamination from cDNA-derived signals in a reverse transcription-polymerase chain reaction. Tissue screening for urocortin expression revealed that the mid-brain is the major site of urocortin mRNA expression, and that other peripheral organs, including lymphoid tissues and peripheral blood lymphocytes, do not produce urocortin.
Collapse
|
365
|
Hahn Y, Lee YJ, Yun JH, Yang SK, Park CW, Mita K, Huh TL, Rhee M, Chung JH. Duplication of genes encoding non-clathrin coat protein gamma-COP in vertebrate, insect and plant evolution. FEBS Lett 2000; 482:31-6. [PMID: 11018518 DOI: 10.1016/s0014-5793(00)02033-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Coatomer is a major component of COPI vesicles and consists of seven subunits. The gamma-COP subunit of the coatomer is believed to mediate the binding to the cytoplasmic dilysine motifs of membrane proteins. We characterized cDNAs for Copg genes encoding gamma-COP from mouse, zebrafish, Drosophila melanogaster and Bombyx mori. Two copies of Copg genes are present in vertebrates and in B. mori. Phylogenetic analysis revealed that two paralogous genes had been derived from a single ancestral gene by duplication independently in vertebrates and in B. mori. Mouse Copg1 showed ubiquitous expression with the highest level in testis. Zebrafish copg2 was biallelically expressed in hybrid larvae in contrast to its mammalian ortholog expressed in a parent-of-origin-specific manner. A phylogenetic analysis with partial plant cDNA sequences suggested that copg gene was also duplicated in the grass family (Poaceae).
Collapse
|
366
|
Kwon TK, Baek S, Lee YJ, Lee Y, Kim J, Kim JH, Suh S, Suh M, Baek W, Bang O, Park J. Failure to induce inhibition of cyclin A and up-regulation of p21 expression in phorbol ester-resistant U937 cells by phorbol ester. Cancer Lett 2000; 157:211-8. [PMID: 10936682 DOI: 10.1016/s0304-3835(00)00492-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Differentiation resistant U937 cells were derived from parental U937 cells by selecting for continuously growing U937 cells in cell cultures continuously exposed to phorbol 12 myristate 13-acetate (PMA). Unlike in other known PMA resistant U937, the basal expression of protein kinase C (PKC) isozymes in these PMA resistant cells (R-U937) was significantly decreased. Subsequent analyses revealed differences between the wild type U937 and the R-U937 cells with respect to G1 phase arrest, which seemed to occur in U937 because of low levels of cdk2 kinase activity. This abolished cdk2 kinase activity is mainly due to inhibition of cdk2 phosphorylation, cyclin A down-regulation and cyclin dependent kinase inhibitor p21 up-regulation. Our data suggest that events down-stream of PKC activation may mediate cell cycle control. Thus, the R-U937 cells could be useful for further PKC mediated cell cycle control studies.
Collapse
|
367
|
Song EY, Kang SJ, Lee YJ, Park MH. HLA-DR2-associated DRB1 and DRB5 alleles and haplotypes in Koreans. Hum Immunol 2000; 61:937-41. [PMID: 11053638 DOI: 10.1016/s0198-8859(00)00155-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
There are considerable racial differences in the distribution of HLA-DR2-associated DRB1 and DRB5 alleles and the characteristics of linkage disequilibrium between these alleles. In this study, the frequencies of DR2-associated DRB1 and DRB5 alleles and related haplotypes were analyzed in 186 DR2-positive individuals out of 800 normal Koreans registered for unrelated bone marrow donors. HLA class I antigen typing was performed by the serological method and DRB1 and DRB5 genotyping by the PCR-single strand conformational polymorphism method. Only 3 alleles were detected for DR2-associated DRB1 and DRB5 genes, respectively: DRB1(*)1501 (gene frequency 8.0%), (*)1502 (3.2%), (*)1602 (0.9%); DRB5(*)0101 (8.0%), (*)0102 (3.2%), and (*)0202 (0.9%). DRB1-DRB5 haplotype analysis showed an exclusive association between these alleles: DRB1*1501-DRB5*0101 (haplotype frequency 8.0%), DRB1(*)1502-DRB5(*)0102 (3.2%), and DRB1(*)1602-DRB5(*)0202 (0.9%). The 5 most common DR2-associated A-B-DRB1 haplotypes occurring at frequencies of > or = 0.5% were A24-B52-DRB1(*)1502 (1.8%), A2-B62-DRB1(*)1501, A2-B54-DRB1(*)1501, A26-B61-DRB1(*)1501, and A24-B51-DRB1(*)1501. The remarkable homogeneity in the haplotypic associations between DR2-associated DRB1 and DRB5 alleles in Koreans would be advantageous for organ transplantation compared with other ethnic groups showing considerable heterogeneity in the distribution of DRB1-DRB5 haplotypes.
Collapse
|
368
|
Lee SH, Kim KA, Park YG, Seong IW, Kim MJ, Lee YJ. Identification and partial characterization of a novel hemolysin from Leptospira interrogans serovar lai. Gene 2000; 254:19-28. [PMID: 10974532 DOI: 10.1016/s0378-1119(00)00293-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
It has been suggested that leptospiral hemolysins are important in the virulence and pathogenesis of leptospirosis. We have isolated an Escherichia coli clone carrying the 7.8kb DNA insert from a genomic library of Leptospira interrogans serovar lai by plaque hybridization using a sequence derived from the sphingomyelinase C gene (sphA) of L. borgpetersenii. The clone showed a clear beta-hemolytic zone on sheep blood agar and high hemolytic activities on both human and sheep erythrocytes in liquid assays. The clone carried at least two genes responsible for the hemolytic activities, encoded by two open reading frames of 1662 and 816 nucleotides, which are named sphH and hap-1 (hemolysis associated protein-1), respectively. The SphH showed 75% homology to the SphA at the amino acid level, and the Hap-1 showed no significant homology in major databases. Interestingly, however, E. coli cells harboring sphH did not show sphingomyelinase or phospholipase activities. Moreover, SphH-mediated hemolysis was osmotically protected by polyethylene glycol 5000, suggesting that the hemolysis is likely to be caused by pore formation on the membrane. The SphH was successfully expressed in E. coli as a histidine (His)-SphH fusion protein. Both sphH and hap-1 were highly conserved among the Leptospira species, except for the absence of sphH in non-pathogenic L. biflexa serovar patoc. We concluded that the SphH is a novel hemolysin of a pathogenic Leptospira species, which may be a putative pore-forming protein.
Collapse
|
369
|
Kim SY, Park KW, Lee YJ, Back SH, Goo JH, Park OK, Jang SK, Park WJ. In vivo determination of substrate specificity of hepatitis C virus NS3 protease: genetic assay for site-specific proteolysis. Anal Biochem 2000; 284:42-8. [PMID: 10933854 DOI: 10.1006/abio.2000.4662] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hepatitis C virus (HCV) NS3 protease is responsible for the processing of the viral polyprotein and is considered as a primary target for the development of anti-HCV therapy. We have developed a genetic method in yeast to screen for good substrate sequences of the NS3 protease. A library of fusion proteins was constructed with a transcription factor, GAL4, linked to the intracellular domain of an integral membrane protein, STE2, by a randomized protease substrate sequence. In yeast cells expressing NS3 protease, the substrate sequences in the fusion proteins were specifically recognized and cleaved. This cleavage resulted in the release of GAL4 from the cytoplasmic membrane and the subsequent activation of reporter genes by GAL4, which was detected by the growth of yeast cells on selective media. Based on the analysis of 69 isolated substrate sequences, a consensus sequence was deduced: (Glu/Asp)-X-Val-Val-(Leu/Pro)-Cys / (Ser/Ala), with the scissile bond being located between Cys and Ser or Ala and X not being determined. This is largely consistent with the previous results obtained by biochemical methods. An oligopeptide containing the deduced sequence was highly efficiently cleaved in vitro by the purified NS3 protease. These data demonstrated that the present genetic method could be used as an efficient tool for the in vivo determination of substrate specificity of proteases.
Collapse
|
370
|
Hamamoto H, Hasegawa K, Nakaune R, Lee YJ, Makizumi Y, Akutsu K, Hibi T. Tandem repeat of a transcriptional enhancer upstream of the sterol 14alpha-demethylase gene (CYP51) in Penicillium digitatum. Appl Environ Microbiol 2000; 66:3421-6. [PMID: 10919801 PMCID: PMC92165 DOI: 10.1128/aem.66.8.3421-3426.2000] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the mechanism of resistance to demethylation inhibitors (DMI) in Penicillium digitatum by isolating the CYP51 gene, which encodes the target enzyme (P450(14DM)) of DMI, from three DMI-resistant and three DMI-sensitive strains. The structural genes of all six strains were identical, but in the promoter region, a unique 126-bp sequence was tandemly repeated five times in the DMI-resistant strains and was present only once in the DMI-sensitive strains. Constitutive expression of CYP51 in the resistant strains was about 100-fold higher than that in the sensitive strains. We introduced CYP51, including the promoter region, from a DMI-resistant strain into a DMI-sensitive strain, which rendered the transformants DMI resistant and increased CYP51 expression. We also found that if the number of copies of the repeat was reduced to two, resistance and CYP51 expression also decreased. These results indicate that the 126-bp unit acts as a transcriptional enhancer and that a tandem repeat of the unit enhances CYP51 expression, resulting in DMI resistance. This is a new fungicide resistance mechanism for filamentous fungi.
Collapse
|
371
|
Spitz DR, Sim JE, Ridnour LA, Galoforo SS, Lee YJ. Glucose deprivation-induced oxidative stress in human tumor cells. A fundamental defect in metabolism? Ann N Y Acad Sci 2000; 899:349-62. [PMID: 10863552 DOI: 10.1111/j.1749-6632.2000.tb06199.x] [Citation(s) in RCA: 252] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recently, glucose deprivation-induced oxidative stress has been shown to cause cytotoxicity, activation of signal transduction (i.e., ERK1, ERK2, JNK, and Lyn kinase), and increased expression of genes associated with malignancy (i.e., bFGF and c-Myc) in MCF-7/ADR human breast cancer cells. These results have led to the proposal that intracellular oxidation/reduction reactions involving hydroperoxides and thiols may provide a mechanistic link between metabolism, signal transduction, and gene expression in these human tumor cells. The current study shows that several other transformed human cell types appear to be more susceptible to glucose deprivation-induced cytotoxicity and oxidative stress than untransformed human cell types. In a matched pair of normal and SV40-transformed human fibroblasts the cytotoxic process is shown to be dependent upon ambient O2 concentration. A theoretical model to explain the results is presented and implications to unifying modern theories of cancer are discussed.
Collapse
|
372
|
Kim SH, Song KJ, Shin YK, Kim JH, Choi SM, Park KS, Baek LJ, Lee YJ, Song JW. Phylogenetic analysis of the small hydrophobic (SH) gene of mumps virus in Korea: identification of a new genotype. Microbiol Immunol 2000; 44:173-7. [PMID: 10789504 DOI: 10.1111/j.1348-0421.2000.tb02479.x] [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: 11/27/2022]
Abstract
Viral RNAs extracted from fifteen mumps virus isolated from throat swab, saliva, blood, urine or CSF during mumps epidemics between 1997-1998 in Korea were amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) and compared by nucleotide sequencing of the small hydrophobic (SH) gene. The deduced amino acid sequences of the SH gene were aligned with the published sequences of mumps virus isolated in different geographic areas. A comparison of the SH gene of mumps viruses in Korea indicated 96.2-100% and 91.2-100% similarity at the nucleotide and amino acid levels, respectively. Phylogenetic analysis, using the neighbor-joining method, showed that Korean mumps virus strains formed a genetically distinct monophyletic group from previously reported genotypes based on the 315-bp length nucleotide and 57 deduced amino acid sequences of the SH gene, and possibly be designated as a new genotype (I).
Collapse
|
373
|
Song SH, Lee KH, Kang MS, Lee YJ. Role of paxillin in metabolic oxidative stress-induced cytoskeletal reorganization: involvement of SAPK signal transduction pathway and PTP-PEST gene expression. Free Radic Biol Med 2000; 29:61-70. [PMID: 10962206 DOI: 10.1016/s0891-5849(00)00326-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Previous studies have shown that glucose deprivation-induced cell death is associated with apoptosis, which is characterized by cellular membrane blebbing in multi-drug-resistant human breast carcinoma MCF-7/ADR cells. In this study, we investigated the mechanism of glucose deprivation-induced cytoskeletal reorganization, which is known to be responsible for the morphological alterations. An increase in the formation of focal adhesion and stress fibers was observed during the early period of glucose deprivation (1-2 h). However, a disappearance of focal adhesion complexes and a loss of stress fiber formation along with membrane blebbing were observed when glucose deprivation continued. These alterations were delayed in MCF-7/ADR cells transfected with bcl-2 and completely suppressed by treatment with an antioxidant, N-acetyl-L-cysteine. These results indicated that glucose deprivation-induced oxidative stress caused the cytoskeletal reorganization. The glucose deprivation-induced alteration of cytoskeletal organization was further investigated by studying a modification of paxillin, one of the focal adhesion proteins. Immunoblotting with anti-paxillin antibody showed that the paxillin band shifted from 68 kDa to about 80 kDa during 1-4 h of glucose deprivation. The mobility shift indicated the modification of paxillin. This possibility was further studied by an immunoprecipitation assay with anti-paxillin/anti-phosphotyrosine antibody and phosphoamino acid analysis (PAA). The immunoprecipitation study revealed that the level of tyrosine phosphorylation of paxillin was maintained for 2 h and then markedly decreased without a change in the total level of paxillin. The PAA study showed that paxillin is dephosphorylated on tyrosine concurrent with phosphorylation on serine/threonine. Expression of a dominant-negative mutant of c-Jun NH(2)-terminal kinase (JNK1) suppressed glucose deprivation-induced JNK1 activation, PTP-PEST gene expression, and alteration of paxillin. Taken together, these results suggest that the alteration of the phosphorylation/dephosphorylation of paxillin may be related to the cytoskeletal reorganization and these events are mediated by glucose deprivation-induced oxidative stress and the stress-activated protein kinase signal transduction pathway.
Collapse
|
374
|
Lee CW, Song CS, Lee YJ, Mo IP, Garcia M, Suarez DL, Kim SJ. Sequence analysis of the hemagglutinin gene of H9N2 Korean avian influenza viruses and assessment of the pathogenic potential of isolate MS96. Avian Dis 2000; 44:527-35. [PMID: 11006999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Sequence analysis of the hemagglutinin (HA) gene of five Korean H9N2 avian influenza virus (AIV) isolates showed that these viruses were closely related and possibly came from the same source. Phylogenetic analysis of the HA1 subunit of H9 subtype isolates revealed that Korean AIV isolates were different from isolates from the poultry markets in Hong Kong in 1997. None of the Korean AIVs had multiple basic amino acids at the HA cleavage site that confer high pathogenicity to some H5 and H7 AIVs. Phylogenetic analysis of the nucleoprotein and matrix gene demonstrated that Korean isolates cluster with Eurasian origin AIVs. The pathogenic potential of one of the isolates (MS96) was assessed after several passages in 14-day-old embryonated chicken eggs (ECE). Fourteen-day-old ECE derivatives of MS96 showed increased HA titer and embryo mortality in eggs; this was apparent after the third passage in 14-day-old ECE. Sequence analysis of the cleavage site of MS96 after the third and tenth passages in 14-day-old ECE revealed no changes in the amino acid sequence. The pathogenicity of MS96 after the tenth passage in 14-day-old eggs (MS96p10(ECE14)) was tested with 4-wk-old specific-pathogen-free chickens. The 14-day-old derivative, MS96p10(ECE14), showed wider tissue tropism and induced more severe clinical signs than the parent virus. Furthermore, after intranasal inoculation of 86-wk-old broiler breeders and 30-wk-old layers, the MS96p10(ECE14) derivative induced more severe signs of depression than the parent virus as well as a transient drop in egg production.
Collapse
|
375
|
Hsieh TJ, Lin SR, Lee YJ, Shin SJ, Lai YH, Hsu CH, Tsai JH. Increased renal medullary endothelin-1 synthesis in prehypertensive DOCA- and salt-treated rats. Am J Physiol Renal Physiol 2000; 279:F112-21. [PMID: 10894793 DOI: 10.1152/ajprenal.2000.279.1.f112] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To investigate the role of renal endothelin-1 (ET-1) synthesis in water-sodium homeostasis, we measured mRNA expressions, protein levels, enzyme activity, and receptor binding of the renal ET-1 system in a DOCA- and salt-treated rat model. Male Wistar rats were divided into control and DOCA- and salt-treated (DOCA-Salt) groups. The DOCA-Salt group received 25 mg/kg body wt DOCA and was maintained on 1% NaCl drinking water. Rats were killed on days 1, 2, 4, and 10 of the experiment. Urinary ET-1-like immunoreactivity significantly increased from the second day in the DOCA-Salt group and correlated well with the urinary sodium excretion rate (r = 0.81, P < 0.001). Renal endothelin-converting enzyme (ECE) activity, ET-1, and ECE-1 mRNA expressions were significantly increased in the renal medullary area of DOCA-Salt rats. In situ hybridization and immunohistochemical studies showed that the increase in ET-1 synthesis was mainly localized in the inner medullary collecting ducts. The maximum binding of endothelin B receptor also increased from the second day in the renal medulla of the DOCA-Salt group. Our results suggest that renal medullary synthesized ET-1 may be a natriuretic factor and may participate in the intrarenal regulation of water and salt homeostasis in prehypertensive DOCA-and salt-treated rats.
Collapse
MESH Headings
- Animals
- Aorta/drug effects
- Aorta/metabolism
- Aspartic Acid Endopeptidases/genetics
- Aspartic Acid Endopeptidases/metabolism
- Blood Pressure/drug effects
- Body Weight/drug effects
- Desoxycorticosterone/pharmacology
- Disease Models, Animal
- Endothelin-1/biosynthesis
- Endothelin-1/genetics
- Endothelin-1/metabolism
- Endothelin-1/urine
- Endothelin-Converting Enzymes
- Hypertension/blood
- Hypertension/metabolism
- Immunohistochemistry
- In Situ Hybridization
- Kidney Medulla/drug effects
- Kidney Medulla/enzymology
- Kidney Medulla/metabolism
- Male
- Metalloendopeptidases
- Organ Size/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptor, Endothelin A
- Receptor, Endothelin B
- Receptors, Endothelin/genetics
- Receptors, Endothelin/metabolism
- Renin/blood
- Sodium Chloride, Dietary/blood
- Sodium Chloride, Dietary/pharmacology
- Sodium Chloride, Dietary/urine
- Water-Electrolyte Balance/drug effects
Collapse
|