576
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Park GT, Jeon DW, Roh KH, Mun HS, Lee CH, Park CH, Kang KW, Kim SM, Kang JM, Park HC. A case of pancytopenia secondary to low-dose pulse methotrexate therapy in a patient with rheumatoid arthritis and renal insufficiency. Korean J Intern Med 1999; 14:85-7. [PMID: 10063319 PMCID: PMC4531911 DOI: 10.3904/kjim.1999.14.1.85] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Most reports on serious MTX toxicity have focused on hepatic abnormalities, while other effects, including hematologic reactions, have not been emphasized. We experienced a case of pancytopenia secondary to MTX therapy in a patient with RA and renal insufficiency. A 67-year-old woman with a 12-year history of active seropositive RA that was a response to non-steroidal anti-inflammatory drugs, hydroxychloroquinine and intra-articular steroid injections, had been followed up and was diagnosed as early chronic renal failure in October, 1993. Recently, because of significant morning stiffness and polyarthralgia, the decision was made to institute MTX treatment. This was begun as a single oral dose of 5mg/week. After 2 doses, the patient was admitted to the hospital with general weakness. Laboratory tests showed a hemoglobin level of 7.9 g/dl, WBC count 1800/mm3 and platelet count of 64000/mm3. The serum creatinine level was 6.1 mEq/dl and the BUN level was 82 mEq/dl. Liver function test results were normal, but the serum albumin level was 2.7 g/dl. The patient subsequently developed fever and blood transfusions, granulocyte colony stimulating factor (G-CSF) and intravenous prophylactic antibiotic therapy were required. Her condition was improved. In summary, Low-dose MTX-related adverse hematologic side effects, including fatal pancytopenia, are rare but are a cause of increasing concern in patients with RA and renal insufficiency. Close monitoring of associated risk factors, particularly impaired renal function, should be mandatory for all patients who are receiving MTX therapy.
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577
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Tsai YH, Lin MC, Hsieh MJ, Chen NH, Tsao TC, Lee CH, Huang CC. Spontaneous variability of arterial oxygenation in critically ill mechanically ventilated patients. Intensive Care Med 1999; 25:37-43. [PMID: 10051076 DOI: 10.1007/s001340050784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To assess the magnitude of spontaneous variability of arterial oxygenation and oxygen tension-based indices over time in medical intensive care unit (ICU) patients and to study whether high positive end-expiratory pressure (PEEP) or inverse inspiratory-to-expiratory (I:E) ratio ventilation (IRV) results in a greater variability than low PEEP with conventional I:E ratio ventilation. DESIGN Prospective study. SETTING Medical ICU in a tertiary medical center. PARTICIPANTS 23 patients requiring a pulmonary artery floating catheter for hemodynamic monitoring. INTERVENTION After being completely sedated, patients were randomized to receive pressure-control ventilation at setting A: high PEEP (15 cm H2O) with conventional I:E ratio (1:2) and setting B: inverse I:E ratio (2:1) with low PEEP (5 cm H2O) alternately, and then at setting C: low PEEP (5 cm H2O) with conventional I:E ratio (1:2). Each ventilation setting lasted 1 h. MEASUREMENTS AND RESULTS The arterial and mixed venous blood samples were measured simultaneously at baseline (time 0), and at 15, 30, 45, and 60 min thereafter. The coefficient of variation (CV) of arterial oxygen tension (PaO2) over time was 5.9 % for setting A, 7.2 % for setting B, and 6.9 % for setting C. ANOVA showed no significant differences in CVs of PaO2 between the three settings. Oxygen tension-based indices, alveolar-arterial oxygen difference (A-aDO2) and PaO2/ PAO2 (alveolar oxygen tension), displayed CVs equal to that of PaO2; the CV of A-aDO2/PaO2 was significantly greater than that of PaO2. CONCLUSIONS In critically ill medical ICU patients, despite sedation, the spontaneous variability in PaO2 over time is substantial. A high PEEP or IRV does not contribute to the increased variation in PaO2.
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578
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Shin HK, Do JC, Son JK, Lee CS, Lee CH, Cheong CJ. Quinoline alkaloids from the fruits of Evodia officinalis. PLANTA MEDICA 1998; 64:764-5. [PMID: 17253323 DOI: 10.1055/s-2006-957579] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A new quinoline derivative, 2-hydroxy-4-methoxy-3-(3'-methyl-2'-butenyl)-quinoline and five known quinoline alkaloids were isolated from the fruits of Evodia officinalis. The structure of 1 was determined by spectroscopic methods.
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579
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Lee YH, Ji JD, Yeon JE, Byun KS, Lee CH, Song GG. Cryoglobulinaemia and rheumatic manifestations in patients with hepatitis C virus infection. Ann Rheum Dis 1998; 57:728-31. [PMID: 10070272 PMCID: PMC1752516 DOI: 10.1136/ard.57.12.728] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES To investigate the association of cryoglobulinaemia and rheumatic manifestations in Korean patients with hepatitis C virus (HCV) infection. METHODS Forty nine Korean patients with HCV infection were recruited. The prevalence, concentration, and type of cryoglobulin (by immunofixation), rheumatoid factor (RF), antinuclear antibody (ANA), and various rheumatological symptoms were investigated and HCV genotype was determined by polymerase chain reaction with genotype specific primer. RESULTS The prevalence of cryoglobulin was 59% in Korean HCV patients and the concentration of cryoglobulin was 9.8 (7.9) g/l (mean (SD)). The type of cryoglobulinaemia was identified in 23 (80%) of 29 HCV patients with cryoglobulinaemia and they were all type III. There were no differences in age, sex, history of operation and transfusion, proportion of liver cirrhosis between the patients with cryoglobulinaemia and those without cryoglobulinaemia. The frequencies of RF and ANA were 14% and 3.4% respectively in HCV patients with cryoglobulinaemia. There was no difference in HCV genotype between the patients with cryoglobulinaemia and those without cryoglobulinaemia. Clinical features of HCV patients were as follows: arthralgia/arthritis (35%), cutaneous manifestation (37%), Raynaud's phenomenon (8%), paresthesia (44%), dry eyes (22%), dry mouth (10%), oral ulcer (33%), and abdominal pain (14%). However, these rheumatological symptoms did not differ between the two groups. CONCLUSION Although the rheumatological symptoms were not different between HCV patients with and without cryoglobulinaemia, HCV patients showed various rheumatological manifestations. These result suggests that HCV infection could be included as one of the causes in patients with unexplained rheumatological symptoms.
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580
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Huang YH, Lee CH, Wu JC, Wang YJ, Chang FY, Lee SD. Functional pancreatic islet cell tumors with liver metastasis: the role of cytoreductive surgery and transcatheter arterial chemoembolization: a report of five cases. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 1998; 61:748-54. [PMID: 9884450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Malignant pancreatic islet tumors are slow-growing tumors. Their relatively benign behavior makes aggressive treatment worthwhile. From January, 1987, to January, 1998, five cases of malignant pancreatic islet tumors with liver metastasis were diagnosed at the Veterans General Hospital-Taipei. Of these, three were gastrinomas and the others were vasoactive intestinal peptide (VIPoma, 1 case) and insulinoma (1 case). Four patients (3 with gastrinomas and 1 with insulinoma) had undergone cytoreductive surgery when the diagnosis of metastasis was made. All five patients underwent transcatheter arterial chemoembolization (TACE). All patients had improved symptoms after cytoreductive surgery and TACE. The survival of patients who underwent combined surgery and TACE was 38 and 17 months in the two gastrinoma cases, more than eight months in one gastrinoma case and more than 20 months in the insulinoma case (these 2 patients are still alive). One VIPoma patient who underwent TACE survived for 12 months. In conclusion, treatment for metastatic pancreatic islet cell tumors require a multidisciplinary approach. Metastasis of the tumor is not a contraindication for aggressive therapy. Combined cytoreductive surgery and TACE can relieve symptoms and are of benefit for patients with pancreatic islet cell tumors with liver metastases.
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581
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Lucas KG, Filo F, Heilman DK, Lee CH, Emanuel DJ. Semiquantitative Epstein-Barr virus polymerase chain reaction analysis of peripheral blood from organ transplant patients and risk for the development of lymphoproliferative disease. Blood 1998; 92:3977-8. [PMID: 9867357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
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582
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Yoo CH, Lee CH, Park YH. Does congested intestinal blood during liver transplantation affect preservation-reperfusion injury? Transplant Proc 1998; 30:3686-7. [PMID: 9838618 DOI: 10.1016/s0041-1345(98)01194-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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583
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Bak YT, Kwon OS, Yeon JE, Kim JS, Byun KS, Kim JH, Kim JG, Lee CH, Choi YH, Kang DH. Endoscopic treatment in a case with extensive spontaneous intramural dissection of the oesophagus. Eur J Gastroenterol Hepatol 1998; 10:969-72. [PMID: 9872621 DOI: 10.1097/00042737-199811000-00012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Spontaneous intramural dissection of the oesophagus has been recognized as a separate clinical entity between a transmural oesophageal rupture (Boerhaave syndrome) and an oesophageal mucosal tear (Mallory-Weiss syndrome). It is important to differentiate this condition from myocardiac infarction, dissecting aneurysm and other acute surgical conditions. Conservative management is usually thought to be adequate. We report a case of spontaneous intramural oesophageal dissection, in which the symptom of dysphagia did not improve with the conservative management and an endoscopic incision of the septum between true and false lumens using a needle-type diathermy knife was done safely and effectively.
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584
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Lee CH, Chinpaisal C, Wei LN. Cloning and characterization of mouse RIP140, a corepressor for nuclear orphan receptor TR2. Mol Cell Biol 1998; 18:6745-55. [PMID: 9774688 PMCID: PMC109258 DOI: 10.1128/mcb.18.11.6745] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/1998] [Accepted: 08/14/1998] [Indexed: 11/20/2022] Open
Abstract
The mouse homologue of the human receptor-interacting protein 140 (RIP140) was isolated from a mouse embryonic cDNA library in yeast two-hybrid screening experiments by using the ligand binding domain (LBD) of nuclear orphan receptor TR2 as the bait. The receptor-interacting domains of mouse RIP140 were mapped to the regions containing the LXXLL motif (where L is leucine and X is any amino acid), and the RIP140-interacting domain of TR2 was mapped to its C-terminal 10- to 20-amino-acid sequence, a putative activation function 2 (AF-2) region. In a GAL4 reporter system and a reporter driven by the proximal region of the TR2 promoter, RIP140 functioned as a corepressor for both a GAL4 DNA binding domain (BD)-TR2 fusion and the wild-type receptor. When tethered to the BD of GAL4, RIP140 exerted a trans-repressive effect on the GAL4 reporter. In addition, RIP140 suppressed the retinoic acid (RA) receptor-mediated RA induction in a dose-dependent manner. Finally, it was demonstrated that in the presence of RIP140, a cytosolic, green fluorescent protein-tagged TR2 LBD translocated into the nucleus, and TR2 and RIP140 were coimmunoprecipitated from the cell extract, indicating that the interaction between RIP140 and the LBD of TR2 occurred in vivo. The potential biological role of RIP140 in TR2-modulated transcriptional activity is discussed.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Amino Acid Sequence
- Animals
- Binding Sites/genetics
- Cloning, Molecular
- DNA-Binding Proteins
- Genes, Reporter/genetics
- Green Fluorescent Proteins
- Luminescent Proteins/immunology
- Mice
- Microscopy, Fluorescence
- Molecular Sequence Data
- Nuclear Proteins/chemistry
- Nuclear Receptor Interacting Protein 1
- Nuclear Receptor Subfamily 2, Group C, Member 1
- RNA, Messenger/analysis
- Receptors, Thyroid Hormone/metabolism
- Repressor Proteins/chemistry
- Saccharomyces cerevisiae Proteins
- Sequence Alignment
- Sequence Analysis, DNA
- Transcription Factors/genetics
- Transcription, Genetic/genetics
- Transfection/genetics
- Tretinoin/pharmacology
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585
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Fok TF, Lee CH, Wong EM, Lyon DJ, Wong W, Ng PC, Cheung KL, Cheng AF. Risk factors for Enterobacter septicemia in a neonatal unit: case-control study. Clin Infect Dis 1998; 27:1204-9. [PMID: 9827270 DOI: 10.1086/514974] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Thirty cases of Enterobacter aerogenes or Enterobacter cloacae septicemia diagnosed over a 32-month period in a tertiary care neonatal unit were enrolled in a case-control study. Each case patient was matched with two controls (patients occupying the cots nearest the case patient when the latter developed septicemia). Of the 32 perinatal characteristics evaluated, 11 were identified by univariate analysis to be significantly associated with the infection. These included parents being residents of the Vietnamese refugee camps, respiratory distress syndrome, necrotizing enterocolitis, umbilical arterial catheterization, umbilical venous catheterization, bladder catheterization, mechanical ventilation, antibiotic treatment, peripheral venous catheterization, nasogastric intubation, and parenteral nutrition. Multivariate analysis, however, showed that preceding bladder catheterization and ongoing parenteral nutrition were the only independent risk factors for enterobacter septicemia. Strict aseptic technique in the preparation of parenteral nutrition fluid and avoidance of bladder catheterization are measures that may reduce the risk of enterobacter sepsis for newborns.
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586
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Ng PC, Fok TF, Lee CH, Cheung KL, Li CK, So KW, Wong W, Yuen PM. Is homozygous alpha-thalassaemia a lethal condition in the 1990s? Acta Paediatr 1998; 87:1197-9. [PMID: 9846925 DOI: 10.1080/080352598750031220] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
Abstract
Two cases of homozygous alpha-thalassaemia who received active treatment in accordance with parental wishes are reported. One infant survived and the other, although successfully weaned off mechanical respiratory support, unexpectedly developed portal vein thrombosis and died. Homozygous alpha-thalassaemia, a condition previously considered to be universally fatal, and an indication for therapeutic abortion, is now potentially curable with advances in diagnostic technology and treatment. However, active management of these cases raises serious ethical questions and has major financial implications on the health-care system. Invasive prenatal and intensive postnatal interventions should remain experimental and cannot be recommended as routine clinical practice until the questions of long-term neurodevelopmental outcome, and the morbidity and mortality associated with bone-marrow transplantation have been fully addressed. As a result of advances in information technology, more and more parents of affected foetuses are likely to request active treatment.
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587
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Lee CH, Vyavahare N, Zand R, Kruth H, Schoen FJ, Bianco R, Levy RJ. Inhibition of aortic wall calcification in bioprosthetic heart valves by ethanol pretreatment: biochemical and biophysical mechanisms. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1998; 42:30-7. [PMID: 9740004 DOI: 10.1002/(sici)1097-4636(199810)42:1<30::aid-jbm5>3.0.co;2-p] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The effectiveness of ethanol pretreatment on preventing calcification of glutaraldehyde-fixed porcine aortic bioprosthetic heart valve (BPHV) cusps was previously demonstrated, and the mechanism of action of ethanol was attributed in part to both lipid removal and a specific collagen conformational change. In the present work, the effect of ethanol pretreatment on BPHV aortic wall calcification was investigated using both rat subdermal and sheep circulatory implants. Ethanol pretreatment significantly inhibited calcification of BPHV aortic wall, but with less than complete inhibition. The maximum inhibition of calcification of BPHV aortic wall was achieved using an 80% ethanol pretreatment; calcium levels were 71.80+/-8.45 microg/mg with 80% ethanol pretreatment compared to the control calcium level of 129.90+/-7.24 microg/mg (p = 0.001). Increasing the duration of ethanol exposure did not significantly improve the inhibitory effect of ethanol on aortic wall calcification. In the sheep circulatory implants, ethanol pretreatment partly prevented BPHV aortic wall calcification with a calcium level of 28.02+/-4.42 microg/mg compared to the control calcium level of 56.35+/-6.14 microg/mg (p = 0.004). Infrared spectroscopy (ATR-FTIR) studies of ethanol-pretreated BPHV aortic wall (vs. control) demonstrated a significant change in protein structure due to ethanol pretreatment. The water content of the aortic wall tissue and the spin-lattice relaxation times (T1) as assessed by proton nuclear magnetic resonance spectroscopy did not change significantly owing to ethanol pretreatment. The optimum condition of 80% ethanol pretreatment almost completely extracted both phospholipids and cholesterol from the aortic wall; despite this, significant calcification occurred. In conclusion, these results clearly demonstrate that ethanol pretreatment is significantly but only partially effective for inhibition of calcification of BPHV aortic wall and this effect may be due in part to lipid extraction and protein structure changes caused by ethanol. It is hypothesized that ethanol pretreatment may be of benefit for preventing bioprosthetic aortic wall calcification only in synergistic combination with another agent.
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588
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Yu Z, Lee CH, Chinpaisal C, Wei LN. A constitutive nuclear localization signal from the second zinc-finger of orphan nuclear receptor TR2. J Endocrinol 1998; 159:53-60. [PMID: 9795341 DOI: 10.1677/joe.0.1590053] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The orphan nuclear receptor TR2 and its truncated isoform deleted in the ligand binding domain (LBD) were localized exclusively in the nuclei as revealed by two methods of detection. An anti-hemagglutinin (HA) antibody detected specific nuclear localization of HA-tagged receptors and the green fluorescent protein (GFP)-tagged receptors were found to be distributed in the nuclei of living cells. By deletion analyses, the sequence responsible for targeting this receptor into the nucleus was defined. A stretch of 20 amino acid residues (KDCVINKHHRNRCQYCRLQR) within the second zinc-finger of this receptor is required for its nuclear localization and this signal is constitutively active. No nuclear localization signal was found in the N-terminus or the LBD. The GFP-tagged receptor remained biologically active, as evidenced by its repressive activity on the reporter that carried a binding site for this receptor, a direct repeat-5 (DR5). An electrophoretic mobility shift assay was performed to characterize the binding property of TR2 and its truncated isoform. TR2 bound to the DR5 as dimers whereas its truncated isoform bound as monomers.
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MESH Headings
- Animals
- COS Cells
- Cell Nucleus/chemistry
- Cell Nucleus/metabolism
- DNA/genetics
- DNA/metabolism
- Electrophoresis
- Genes, Reporter
- Green Fluorescent Proteins
- Luminescent Proteins/metabolism
- Microscopy, Fluorescence
- Nuclear Receptor Subfamily 2, Group C, Member 1
- Protein Isoforms
- Receptors, Cytoplasmic and Nuclear/analysis
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Steroid/analysis
- Receptors, Steroid/metabolism
- Receptors, Thyroid Hormone/analysis
- Receptors, Thyroid Hormone/metabolism
- Recombinant Fusion Proteins/genetics
- Transfection
- Zinc Fingers
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589
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Pang VF, Lee CH, Chiou MT, Yu JF, Jeng CR, Ting CT. Biliary cystadenoma in a striped skunk (Mephitis mephitis). J Vet Diagn Invest 1998; 10:357-60. [PMID: 9786524 DOI: 10.1177/104063879801000408] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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590
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Abstract
P-glycoproteins (Pgp) are comprised of a small family of plasma membrane proteins whose abundance in cultured cells is often associated with the multidrug resistance phenotype. Overexpression of Pgp has been observed in many types of human cancers, but the molecular basis for this overexpression has not been established. We have used primary monolayer cultures of adult rat hepatocytes and a stepwise model of rat liver carcinogenesis to study the regulation of Pgp gene expression. We observed a marked overexpression of Pgp, specifically the class II Pgp, in both systems. In addition, we observed that a number of unrelated genes including alpha-tubulin, beta-actin, gamma-actin, cytokeratin 8, cytokeratin 18, and c-myc are overexpressed in cultured hepatocytes, and they are also overexpressed during liver carcinogenesis and in transplantable tumors. Nuclear run-on assays showed no increase in the transcriptional activity of Pgp genes in transplantable liver tumors compared to normal liver. Studies of in vivo mRNA stability, however, revealed that all three Pgp mRNAs were relatively stable in transplantable liver tumors (t(1/2) > 12 h), in contrast to what was found in normal liver (t(1/2) < 2 h). In addition, mRNA for several other genes, including alpha-tubulin, c-myc, and cyclin D1, all appear to be stabilized in the tumors. These findings suggest that the overexpression of Pgp genes in rat liver tumors may be the result of a mechanism involving stabilization of a diverse group of mRNAs.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- Animals
- Connexins/genetics
- Cyclin D1/genetics
- Gene Expression Regulation, Neoplastic
- Genes, myc/genetics
- Liver Neoplasms
- Male
- Neoplasm Transplantation
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred F344
- Transcription, Genetic/physiology
- Tubulin/genetics
- Tumor Cells, Cultured/chemistry
- Tumor Cells, Cultured/metabolism
- Tumor Cells, Cultured/transplantation
- Gap Junction beta-1 Protein
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591
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Lee CH, Leeds P, Ross J. Purification and characterization of a polysome-associated endoribonuclease that degrades c-myc mRNA in vitro. J Biol Chem 1998; 273:25261-71. [PMID: 9737991 DOI: 10.1074/jbc.273.39.25261] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The regulation of mRNA half-lives is determined by multiple factors, including the activity of the messenger RNases (mRNases) responsible for destroying mRNA molecules. Previously, we used cell-free mRNA decay assays to identify a polysome-associated endonuclease that cleaves c-myc mRNA within the coding region. A similar activity has been solubilized and partially purified from a high salt extract of adult rat liver polysomes. Based on a correlation between protein and enzyme activity, the endonuclease is tentatively identified as a approximately 39-kDa protein. It cleaves the coding region stability determinant of c-myc mRNA with considerable specificity. Cleavages occur predominantly in an A-rich segment of the RNA. The endonuclease is resistant to RNase A inhibitors, sensitive to vanadyl ribonucleoside complex, and dependent on magnesium. In these and other respects, the soluble enzyme we have purified resembles the polysome-associated c-myc mRNase.
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592
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Lee CH, Chinpaisal C, Wei LN. A novel nuclear receptor heterodimerization pathway mediated by orphan receptors TR2 and TR4. J Biol Chem 1998; 273:25209-15. [PMID: 9737983 DOI: 10.1074/jbc.273.39.25209] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A unique heterodimerization pathway involving orphan receptors TR2 and TR4 is demonstrated. TR2 and TR4 preferentially form heterodimers in solution as well as on DNA elements containing a direct repeat-5 (DR5). The in vitro interaction between TR2 and TR4 is demonstrated by the yeast and the mammalian two-hybrid interaction assays, the pull-down assay, and the gel mobility shift assay. The in vivo interaction is demonstrated by following the intracellular localization of fusion receptors tagged with a green fluorescent protein. The dimerization is mediated by the ligand binding domains, and the three leucine residues on helix 10 of TR2 are critical for this interaction. In addition, coexpression of these two receptors exerts a much stronger repressive activity on a DR5-containing reporter than expressing either receptor alone. In the developing testis, TR2 and TR4 are coexpressed in the same testicular cell populations and exhibit a parallel pattern of expression along development. The preferential heterodimerization between TR2 and TR4 and their coexistence in specific germ cell populations suggest a physiological role of TR2/TR4 heterodimers in germ cell development.
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593
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Li LF, Lin MC, Chen NH, Hsieh MJ, Lee CH, Tsao TC. Serodiagnosis of tuberculosis by enzyme-linked immunosorbent assay for anti-A60 and anti-A38. CHANGGENG YI XUE ZA ZHI 1998; 21:258-64. [PMID: 9849005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
BACKGROUND For early diagnosis of tuberculosis (TB), especially in the patients without adequate sputum specimens for examination, we found a simple, rapid and inexpensive method among many current available diagnostic tools, the enzyme-linked immunosorbent assay (ELISA). To investigate the diagnostic effectiveness of this method, we applied ELISA for detection of antigen 60 IgG and IgM as well as antigen 38 IgG antibodies at Chang Gung Memorial Hospital from April 1995 through June 1996. MATERIALS AND METHODS Sixty-seven patients were enrolled and divided into 3 groups, Group A (n = 24), patients with positive sputum acid-fast stain; Group B (n = 18), patients with lung cancer and negative sputum acid-fast stain; and Group C (n = 25), patients with chest roentgenogram (CXR) which were suggestive of TB but with negative acid-fast stain results or no sputum for examination. RESULTS For the A60 IgG antibody, we found a sensitivity rate of 91.7% for Group A and Group B, and 85.7% for Group C as well as an overall sensitivity of 89.5% but with lower specificity. For the A60 IgM antibody, a lower sensitivity (37.5%, 14.3%, 28.9%, respectively) was found but with higher specificity. For the A38 IgG antibody, we found a lower sensitivity (40%, 11.1%, 31%, respectively) but with higher specificity (100%, 71.4%, 90%, respectively). CONCLUSION With a high sensitivity but low specificity for diagnosis of TB, A60 IgG ELISA could be used as a rapid, simple screening test for patients with results suggestive of TB, especially in those who had no sputum or had negative sputum acid-fast stain results. Otherwise, A60 IgM or A38 IgG ELISA, with a high specificity, could be used as a reliable test in the diagnosis of pulmonary TB when the result is positive. In summary, although ELISA is a simple, rapid, inexpensive method, it is helpful but limited in the diagnosis of pulmonary TB.
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594
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Tang X, Bartlett MS, Smith JW, Lu JJ, Lee CH. Determination of copy number of rRNA genes in Pneumocystis carinii f. sp. hominis. J Clin Microbiol 1998; 36:2491-4. [PMID: 9705380 PMCID: PMC105150 DOI: 10.1128/jcm.36.9.2491-2494.1998] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Differential PCR was performed to determine the copy number of rRNA genes in Pneumocystis carinii f. sp. hominis. Two different reference genes, thymidylate synthase (TS) and beta-tubulin (BTU) genes, were used. Primers for the internal transcribed spacer (ITS) region of nuclear rRNA genes and either the TS or BTU gene were mixed together to perform PCR on seven different bronchoalveolar lavage specimens from patients with P. carinii pneumonia. The radioactivity derived from the incorporated radioactive nucleotides of each PCR product band was then used to calculate the copy number of the ITS relative to that of the TS or BTU gene. The copy number ratio between the ITS and the TS gene was determined to be 0.8, and that between the ITS and the BTU gene was also 0.8. These results suggest that the ITS has the same copy number as the TS or BTU gene. Since the copy number of the TS or BTU gene is presumed to be 1, the results also suggest that P. carinii f. sp. hominis has only one copy of the ITS and thus one copy of the nuclear rRNA genes. Therefore, two types of ITS sequences derived from a specimen would indicate that the patient is infected by two types of P. carinii f. sp. hominis.
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595
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Siu YK, Ng PC, Fung SC, Lee CH, Wong MY, Fok TF, So KW, Cheung KL, Wong W, Cheng AF. Double blind, randomised, placebo controlled study of oral vancomycin in prevention of necrotising enterocolitis in preterm, very low birthweight infants. Arch Dis Child Fetal Neonatal Ed 1998; 79:F105-9. [PMID: 9828735 PMCID: PMC1720837 DOI: 10.1136/fn.79.2.f105] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
AIMS To evaluate the effectiveness of oral vancomycin in the prophylaxis of necrotising enterocolitis in preterm, very low birthweight infants. METHODS A prospective, double blind, randomised, placebo controlled study in a tertiary referral centre of a university teaching hospital was conducted on 140 very low birthweight infants consecutively admitted to the neonatal unit. The babies were randomly allocated to receive oral vancomycin (15 mg/kg every 8 hours for 7 days) or an equivalent volume of placebo solution. Prophylaxis was started 24 hours before the start of oral feeds. All suspected cases of necrotising enterocolitis were investigated with a full sepsis screen and serial abdominal radiographs. Necrotising enterocolitis was diagnosed and staged according to modified Bell's criteria. RESULTS Nine of 71 infants receiving oral vancomycin and 19 of 69 infants receiving the placebo solution developed necrotising enterocolitis (p = 0.035). Infants with necrotising enterocolitis were associated with a significant increase in mortality (p = 0.026) and longer duration of hospital stay (p = 0.002). CONCLUSIONS Prophylactic oral vancomycin conferred protection against necrotising enterocolitis in preterm, very low birthweight infants and was associated with a 50% reduction in the incidence. However, widespread implementation of this preventive measure is not recommended, as it would only be effective in necrotising enterocolitis caused by Gram positive organisms and could increase the danger of the emergence of vancomycin resistant or dependent organisms. Its use should be restricted to a high prevalence nursery for a short and well defined period in a selected group of high risk patients.
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596
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Lee CH, Shin IC, Kang JS, Koh HC, Ha JH, Min CK. Differential coupling of G alpha q family of G-protein to muscarinic M1 receptor and neurokinin-2 receptor. Arch Pharm Res 1998; 21:423-8. [PMID: 9875470 DOI: 10.1007/bf02974637] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The ligand binding signals to a wide variety of seven transmembrane cell surface receptors are transduced into intracellular signals through heterotrimeric G-proteins. Recently, there have been reports which show diverse coupling patterns of ligand-activated receptors to the members of Gq family alpha subunits. In order to shed some light on these complex signal processing networks, interactions between G alpha q family of G protein and neurokinin-2 receptor as well as muscarinic M1 receptor, which are considered to be new therapeutic targets in asthma, were studied. Using washed membranes from Cos-7 cells co-transfected with different G alpha q and receptor cDNAs, the receptors were stimulated with various concentrations of carbachol and neurokinin A and the agonist-dependent release of [3H]inositol phosphates through phospholipase C beta-1 activation was measured. Differential coupling of G alpha q family of G-protein to muscarinic M1 receptor and neurokinin-2 receptor was observed. The neurokinin-2 receptor shows a ligand-mediated response in membranes co-transfected with G alpha q, G alpha 11 and G alpha 14 but not G alpha 16 and the ability of the muscarinic M1 receptor to activate phospholipase C through G alpha q/11 but not G alpha 14 and G alpha 16 was demonstrated. Clearly G alpha q/11 can couple M1 and neurokinin-2 receptor to activate phospholipase C. But, there are differences in the relative coupling of the G alpha 14 and G alpha 16 subunits to these receptors.
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597
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Abstract
Nasal polyps are the most common mass lesion of the nasal cavity. Various pathogenetic mechanisms have been proposed. However, the cause is still largely unknown, and treatment methods have not been changed for several hundred years. In order to investigate the role of cytokines in the pathogenesis of nasal polyps, expression of cytokine messenger RNAs (mRNAs) in nasal polyps was investigated. We performed reverse transcriptase-polymerase chain reaction and Southern blot to examine gene expression of the cytokines interleukin (IL)-1 beta, IL-6, IL-8, transforming growth factor (TGF)-beta, IL-4, IL-5, and interferon (IFN)-gamma and compared the results with the gene expressions of these cytokines in normal nasal mucosa. Nasal polyp tissues were obtained from 14 patients undergoing polypectomy for nasal obstruction. Among them, 4 patients suffered from associated perennial allergic rhinitis. The mRNAs of IL-4 and IL-5 (Th2 cytokines) as well as IFN-gamma (Th1 cytokine) were expressed in all of the nasal polyps obtained from the 14 patients, irrespective of the presence or absence of allergy, while 2, 0, and 4 of 6 normal turbinate mucosae expressed IL-4, IL-5, and IFN-gamma mRNAs, respectively. The mRNAs of IL-1 beta, IL-6, IL-8, and TGF-beta were expressed in 6, 1, 2, and 3 of 6 normal turbinate mucosae, respectively, while the mRNAs of these cytokines were expressed in all of the 14 polyp tissues except IL-6 mRNA, which was expressed in 13 nasal polyp tissues. There were no differences in the mean density ratios of each cytokine band on Southern blot between polyp tissues with allergy and those without allergy. These results suggest that many cytokines are produced in nasal polyps, that they may play important roles in the pathogenesis of nasal polyps, and that allergy per se may not play a fundamental role in the pathogenesis of nasal polyps.
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598
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Chinpaisal C, Lee CH, Wei LN. Mechanisms of the mouse orphan nuclear receptor TR2-11-mediated gene suppression. J Biol Chem 1998; 273:18077-85. [PMID: 9660764 DOI: 10.1074/jbc.273.29.18077] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mouse orphan nuclear receptor TR2-11 functions as a repressor for reporter genes containing a direct repeat-5 or direct repeat-4 hormone response element. The functional domains responsible for its suppressive activity are defined, including the DNA-binding domain and the ligand-binding domain. The C-terminal 30 amino acid residues can be deleted without compromising its suppressive activity, whereas a deletion for 40 amino acids completely abolishes the suppressive activity and receptor dimerization, and reduces the DNA-binding affinity. Point mutation at three conserved leucine residues located on the predicted dimer interface abolishes the suppressive activity, receptor dimerization and its DNA binding property. However, mutation at two consecutive glutamate residues located within the hinge between the last two helices of the ligand-binding domain (helix 10 and helix 11 according to the human retinoid receptor X alpha structure) drastically reduces its DNA-binding affinity and abrogates the suppressive activity without compromising its ability to dimerize, indicating that receptor dimerization property can be functionally uncoupled from its suppressive activity. A transferable, active silencing activity is encoded within the DEF segment of the receptor molecule, as evidenced by the suppression of a GAL4 reporter by a chimeric protein containing the DNA-binding domain of GAL4 and the DEF segment of TR2-11. Moreover, the C-terminal 49 amino acid sequence is required for this trans-suppressive activity. It is suggested that TR2-11 functions as a repressor, mediated by mechanisms requiring high affinity DNA binding, receptor dimerization, and active silencing.
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MESH Headings
- Amino Acid Sequence
- Animals
- DNA/metabolism
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/physiology
- Dimerization
- Genes, Reporter/drug effects
- Humans
- Mice
- Molecular Sequence Data
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Nuclear Proteins/physiology
- Nuclear Receptor Co-Repressor 1
- Nuclear Receptor Subfamily 2, Group C, Member 1
- Point Mutation
- Receptors, Retinoic Acid/metabolism
- Receptors, Steroid/genetics
- Receptors, Steroid/physiology
- Receptors, TNF-Related Apoptosis-Inducing Ligand
- Receptors, Thyroid Hormone/genetics
- Receptors, Thyroid Hormone/physiology
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/metabolism
- Repressor Proteins/metabolism
- Repressor Proteins/physiology
- Retinoid X Receptors
- Saccharomyces cerevisiae Proteins
- Structure-Activity Relationship
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Tretinoin/pharmacology
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599
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Lee CH, Cowburn D, Kuriyan J. Peptide recognition mechanisms of eukaryotic signaling modules. Methods Mol Biol 1998; 84:3-31. [PMID: 9666439 DOI: 10.1385/0-89603-488-7:3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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600
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Manjunath S, Lee CH, VanWinkle P, Bailey-Serres J. Molecular and biochemical characterization of cytosolic phosphoglucomutase in maize. Expression during development and in response to oxygen deprivation. PLANT PHYSIOLOGY 1998; 117:997-1006. [PMID: 9662542 PMCID: PMC34954 DOI: 10.1104/pp.117.3.997] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/1997] [Accepted: 03/30/1998] [Indexed: 05/18/2023]
Abstract
Phosphoglucomutase (PGM) catalyzes the interconversion of glucose (Glc)-1- and Glc-6-phosphate in the synthesis and consumption of sucrose. We isolated two maize (Zea mays L.) cDNAs that encode PGM with 98.5% identity in their deduced amino acid sequence. Southern-blot analysis with genomic DNA from lines with different Pgm1 and Pgm2 genotypes suggested that the cDNAs encode the two known cytosolic PGM isozymes, PGM1 and PGM2. The cytosolic PGMs of maize are distinct from a plastidic PGM of spinach (Spinacia oleracea). The deduced amino acid sequences of the cytosolic PGMs contain the conserved phosphate-transfer catalytic center and the metal-ion-binding site of known prokaryotic and eukaryotic PGMs. PGM mRNA was detectable by RNA-blot analysis in all tissues and organs examined except silk. A reduction in PGM mRNA accumulation was detected in roots deprived of O2 for 24 h, along with reduced synthesis of a PGM identified as a 67-kD phosphoprotein on two-dimensional gels. Therefore, PGM is not one of the so-called "anaerobic polypeptides." Nevertheless, the specific activity of PGM was not significantly affected in roots deprived of O2 for 24 h. We propose that PGM is a stable protein and that existing levels are sufficient to maintain the flux of Glc-1-phosphate into glycolysis under O2 deprivation.
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MESH Headings
- Aerobiosis
- Amino Acid Sequence
- Cloning, Molecular
- Cytosol/enzymology
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Genes, Plant/genetics
- Hypoxia
- Isoenzymes/analysis
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Molecular Sequence Data
- Multigene Family/genetics
- Phosphoglucomutase/genetics
- Phosphoglucomutase/metabolism
- Phosphoproteins/analysis
- Plant Roots/enzymology
- Plant Roots/metabolism
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Homology, Amino Acid
- Transcription, Genetic/genetics
- Zea mays/chemistry
- Zea mays/enzymology
- Zea mays/genetics
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