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C-H Chen

Publications and source records attributed to C-H Chen.

At least 37 records · Page 2Linked to original sources
PubMed2005

Angiotensin-converting enzyme gene insertion/deletion polymorphism is associated with risk of oral precancerous lesion in betel quid chewers.

To investigate whether angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism is related to the risk of oral precancerous lesions (OPL) in Taiwanese subjects who chew betel quid, a total of 61 betel quid chewers having OPL were compared with 61 asymptomatic betel quid chewers matched for betel quid chewing duration and dosage. The frequency of homozygote for ACE D variant is significantly higher in the case subjects than that of the controls (44.3 vs 24.6%; P = 0.0108). The adjusted odds ratio of the D homozygous for the risk of OPL is 8.10 (95% confidence interval (CI) = 2.04-32.19, P = 0.003). In the allelic base analysis, the D allele is also significantly associated with higher risk of OPL. When grouping the study subjects by smoking status, the association between ACE I/D polymorphism and risk of OPL was only observed in nonsmokers. Our results support the theory that genetic factors may contribute to the susceptibility of OPL and suggest that smoking and genetic factors may be differently involved in the development of OPL.

Adult↗
PubMed2005

The role of transcatheter arterial embolization for patients with unresectable hepatocellular carcinoma: a nationwide, multicentre study evaluated by cancer stage.

BACKGROUND: Transcatheter arterial embolization is a major palliative treatment for unresectable hepatocellular carcinoma, but the survival benefit of transcatheter arterial embolization is controversial. AIM: To evaluate the role of transcatheter arterial embolization in different stage of unresectable hepatocellular carcinoma and to select patients who can get the best benefit from the treatment. METHODS: From 1991 to 1995, 476 patients who had unresectable hepatocellular carcinoma from four medical centres in Taiwan were enrolled. Among them, 425 underwent transcatheter arterial embolization, and 51 received supportive treatment alone. The survivals between the two groups were compared. RESULTS: Among the 476 patients, transcatheter arterial embolization can significantly prolong survival. The 1-, 2-, and 5-year survival rates for patients who underwent transcatheter arterial embolization were 60.2%, 39.3%, and 11.5%; and the rates for patients who underwent supportive treatment were 37.3%, 17.6%, and 2%, respectively (P = 0.0002). The survival benefit of transcatheter arterial embolization was observed in patients between Cancer and the Liver Italian Program 0 and Cancer and the Liver Italian Program 4. In multivariate analysis, transcatheter arterial embolization, tumour size <5 cm and earlier Cancer and the Liver Italian Program stage were independent factors associated with a better survival. CONCLUSIONS: For patients who fulfilled the criteria of transcatheter arterial embolization, embolization can serve as a primary treatment for patients with unresectable hepatocellular carcinoma. The survival benefit of transcatheter arterial embolization is regardless of tumour stages.

Carcinoma, Hepatocellular↗
PubMed2005

Characterization of new O3:K6 strains and phylogenetically related strains of Vibrio parahaemolyticus isolated in Taiwan and other countries.

AIMS: We analysed the genetic divergence in the pandemic new O3:K6 and phylogenetically related (new O3:K6-like) strains and compare these two groups in terms of virulence and other biological traits. METHODS AND RESULTS: A total of 160 new O3:K6, new O3:K6-like and other strains of Vibrio parahaemolyticus isolated in Taiwan and other countries were collected and their clonal relationships analysed using SfiI-pulsed-field gel electrophoresis. All of the new O3:K6 and new O3:K6-like strains were grouped in cluster I with five new patterns identified. A O6:K18 strain was identified as a new member of the new O3:K6-like strains in addition to O4:K68, O1:KUT and O1:K25 strains. All of the lipopolysaccharide preparations of the selected strains exhibited closely spaced quadruplet banding patterns with similar mobility. The two groups of strains exhibited 100% sequence identity in the internal sequences of the toxR and laf genes, and also displayed similar virulence properties as determined with a suckling mouse model. CONCLUSIONS: The new O3:K6 and new O3:K6-like strains were highly similar in virulence and in several other phenotypical and genotypical traits. SIGNIFICANCE AND IMPACT OF THE STUDY: This work demonstrated the spread and divergence of the pandemic and related clone of V. parahaemolyticus with similar virulence.

Animals↗
PubMed2005

Mononeuropathy multiplex and chylothorax as earlier manifestations of pulmonary tuberculosis.

Mononeuropathy multiplex (MNM) and chylothorax are rare clinical disorders. The concurrence of these two disorders with Mycobacterium tuberculosis infection has not been reported. We herein report a patient who was initially diagnosed with fever of unknown origin and MNM, and then developed chylothorax. Pulmonary tuberculosis was proved 1 month after chylothorax appeared. With low-dose prednisolone 15 mg day(-1) and anti-tuberculosis drugs, all these disorders completely resolved 1 year later.

Aged↗
PubMed2005

Development of highly potent and selective dynorphin A analogues as new medicines.

Dynorphin A (Dyn A), a 17 amino acid peptide H-Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Pro-Lys-Leu-Lys-Trp-Asp-Asn-Gln-OH, is a potent opioid peptide which interacts preferentially with kappa-opioid receptors. Research in the development of selective and potent opioid peptide ligands for the kappa-receptor is important in mediating analgesia. Several cyclic disulphide bridge-containing peptide analogues of Dyn A, which were conformationally constrained in the putative message or address segment of the opioid ligand, were designed, synthesized and assayed. To further investigate the conformational and topographical requirements for the residues in positions 5 and 11 of these analogues, a systematic series of Dyn A(1-11)-NH2 cyclic analogues incorporating the sulphydryl-containing amino acids L- and D-Cys and L- and D-Pen in positions 5 and 11 were synthesized and assayed. Cyclic lactam peptide analogues were also synthesized and assayed. Several of these cyclic analogues, retained the same affinity and selectivity (vs. the mu- and delta-receptors) as the parent Dyn A(1-11)-NH2 peptide in the guinea-pig brain (GPB), but exhibited a much lower activity in the guinea-pig ileum (GPI), thus leading to centrally vs. peripherally selective peptides. Studies of the structure-activity relationship of Dyn A peptide provide new insights into the importance of each amino acid residue (and their configurations) in Dyn A analogues for high potency and good selectivity at kappa-opioid receptors. We report herein the progress towards the development of Dyn A peptide ligands, which can act as agonists or antagonists at cell surface receptors that modulate cell function and animal behaviour using various approaches to rational peptide ligand-based drug design.

Animals↗
PubMed2005

Incidence rates of oral cancer and oral pre-cancerous lesions in a 6-year follow-up study of a Taiwanese aboriginal community.

BACKGROUND: In a previous article, we reported the prevalence rates of oral mucosal lesions in an aboriginal community from an epidemiological survey of oral pre-cancerous lesions. METHODS: Since 1997, the authors have started regular follow-up of the study population originally investigated. Thus, it has been possible to obtain incidence rates for the various oral pre-cancerous lesions and conditions. RESULTS: There were 194 persons without any oral lesion in the 1997 screening. During the clinical follow-up investigation and during the analysis of biopsies from pre-cancerous lesions, we discovered six new lesions (including cancer and pre-cancerous lesions) from five participants. All of the five persons were areca/betel quid chewers, and only one mixed areca/betel quid chewing with cigarette smoking habit. The age-standardized incidence rates for quid lesion, oral submucous fibrosis (OSF) and squamous cell carcinoma (SCC) were 267.0, 374.1 and 146.2 per 100,000 person-years, respectively, for areca/betel quid chewers. CONCLUSIONS: As compared with the rates from India and the general Taiwanese population, the study community encountered a serious problem of oral lesions.

Adult↗
PubMed2005

The effects of chewing areca/betel quid with and without cigarette smoking on oral submucous fibrosis and oral mucosal lesions.

OBJECTIVES: The purpose of this study was to investigate the risk of areca/betel quid chewing with or without cigarette smoking on oral submucous fibrosis (OSF) and other oral mucosal lesions. METHODS: A stratified case-control study was designed. There were in total 102 patients with oral mucosal lesions or OSF (confirmed pathologically) in the case group. OSF (n = 62) and oral mucosal lesions (n = 62) in 102 subjects were separately analyzed for men and women investigating their risks. RESULTS: For OSF, people with both smoking and chewing habits had a statistically significant odds ratio (OR) 8.68 (95% CI = 1.87, 40.23). For the group of people with chewing habit only and without any lifetime cigarette smoking habit, the OR was 4.51 (95% CI = 1.20, 16.94). For other oral mucosal lesions, people with mixed habits and chewing only had also significant risks (OR = 8.37 and 3.95, respectively). For both OSF and other oral lesions, the ORs of mixed habits and chewing only were both higher in women than in men. CONCLUSIONS: The areca/betel quid used in Taiwan does not contain any tobacco product. The only way of areca/betel quid could synergize with any tobacco product is through cigarette smoking. A statistically significant association with oral mucosal lesions and OSF was still found in the group of areca/betel quid chewing only.

Adult↗
PubMed2005

Inhibition of angiotensin II induced endothelin-1 gene expression by 17-beta-oestradiol in rat cardiac fibroblasts.

OBJECTIVE: To examine whether 17-beta-oestradiol (E(2)) may alter angiotensin II (Ang II) induced cell proliferation and to identify the putative underlying signalling pathways in rat cardiac fibroblasts. DESIGN: Cultured rat cardiac fibroblasts were preincubated with E(2) then stimulated with Ang II. [(3)H]Thymidine incorporation and endothelin-1 (ET-1) gene expression were examined. The effect of E(2) on Ang II induced NADPH oxidase activity, reactive oxygen species (ROS) formation, and extracellular signal regulated kinase (ERK) phosphorylation were tested to elucidate the intracellular mechanism of E(2) in proliferation and ET-1 gene expression. RESULTS: Ang II increased DNA synthesis, which was inhibited with E(2) (1-100 nmol/l). E(2), but not 17-alpha-oestradiol, inhibited Ang II induced ET-1 gene expression as shown by northern blotting and promoter activity assay. This effect was prevented by co-incubation with the oestrogen receptor antagonist ICI 182,780 (1 micromol/l). E(2) also inhibited Ang II increased NADPH oxidase activity, ROS formation, ERK phosphorylation, and activator protein-1 mediated reporter activity. CONCLUSIONS: The results suggest that E(2) inhibits Ang II induced cell proliferation and ET-1 gene expression, partially by interfering with the ERK pathway through attenuation of ROS generation. Thus, this study provides important new insight regarding the molecular pathways that may contribute to the proposed beneficial effects of oestrogen on the cardiovascular system.

Angiotensin II↗
PubMed2005

Primary intraosseous carcinoma of the mandible.

Primary intraosseous carcinoma (PIOC) is a rare lesion in the jawbone. We report a case of de novo PIOC of the mandible, first seen by the family dentist. Our case highlights that radiographic examination is one of the most effective methods for detecting PIOCs.

Aged↗
PubMed2004

Effects of tannic acid and its related compounds on food mutagens or hydrogen peroxide-induced DNA strands breaks in human lymphocytes.

The effect of tannic acid (TA), gallic acid (GA), propyl gallate (PA) and ellagic acid (EA) on DNA damage in human lymphocytes induced by food mutagens [3-amino-1-methyl-5H-pyrido (4,3-b) indole (Trp-P-2) and 2-amino-1-methyl-6-phenylimadazo (4,5-b) pyridine (PhIP) or H2O2 was evaluated by using single-cell electrophoresis (comet assay). The toxicity of these tested compounds (0.1-100 microg/ml) on lymphocytes was not found. These compounds did not cause DNA strand breaks at lower concentrations of 0.1-10 microg/ml. At a concentration of 100 microg/ml, TA and GA exhibited slight DNA damage, whereas PA and EA showed no DNA strand breaks. TA and its related compounds decreased the DNA strand breaks induced by Trp-P-2, PhIP or H2O2 at concentrations of 0.1-10 microg/ml. DNA repair enzymes endonuclease III (Endo III) and formamidopyrimidine-DNA glycoslase (FPG)] were used to examine the levels of oxidised pyrimidines and purines in human lymphocytes induced by H2O2. All the compounds at 10 microg/ml can reduce the level of FPG sensitive sites. However, only EA inhibited the formation of EndoIII sensitive sites. The results indicated that these compounds can enhance lymphocytes resistance towards DNA strand breaks induced by food mutagens or H2O2 in vitro.

DNA Damage↗
PubMed2004

Detection and quantification of copper-denitrifying bacteria by quantitative competitive PCR.

We developed a quantitative competitive PCR (QC-PCR) system to detect and quantify copper-denitrifying bacteria in environmental samples. The primers were specific to copper-dependent nitrite reductase gene (nirK). We were able to detect about 200 copeis of nirK in the presence of abundant non-specific target DNA and about 1.2 x 10(3)Pseudomonas sp. G-179 cells from one gram of sterilized soil by PCR amplification. A 312-bp nirK internal standard (IS) was constructed, which showed very similar amplification efficiency with the target nirKfragment (349 bp) over 4 orders of magnitude (10(3)-10(6)). The accuracy of this system was evaluated by quantifying various known amount of nirK DNA. The linear regressions were obtained with a R(2) of 0.9867 for 10(3)copies of nirK, 0.9917 for 10(4) copies of nirK, 0.9899 for 10(5) copies of nirK and 0.9846 for 10(6) copies of nirK. A high correlation between measured nirK and calculated nirK (slope of 1.0398, R(2)=0.9992) demonstrated that an accurate measurement could be achieved with this system. Using this method, we quantified nirK in several A-horizon and stream sediment samples from eastern Tennessee. In general, the abundance of nirK was in the range of 10(8)-10(9) copies g soil(-1) dry weight. The nirK content in the soil samples appeared correlated with NH(4)(N) content in the soil. The activities of copper-denitrifying bacteria were evaluated by quantifying cDNA of nirK. In most of sample examined, the content of nirK cDNA was less than 10(5) copies g soil(-1) dry weight. Higher nirK cDNA content (>10(6) copies g soil(-1) dry weight) was detected from both sediment samples at Rattlebox Creek and the Walker Branch West Ridge. Although the stream sediment samples at the Walker Branch West Ridge contained less half of the nirK gene content as compared to A-horizon sample, the activities of copper-denitrifying bacteria were almost 600 times higher than in the A-horizon sample.

Copper↗
PubMed2004

Sirolimus in chronic allograft nephropathy.

Chronic allograft nephropathy (CAN) is the most common cause of late renal transplant loss. Calcineurin inhibitor (CNI) nephrotoxicity is known to contribute to CAN. A sirolimus-based regimen way allow for early CNI reduction or elimination. The aim of the present study was to determine the efficacy and safety of a sirolimus-based regimen for CAN. From December 2001 to August 2003, kidney transplant (KTx) recipients with CAN were enrolled for treatment with sirolimus. Among 32 studied patients, 24 (75%) underwent graft biopsy before the initiation of sirolimus. Baseline maintenance immunosuppression consisted of cyclosporine/tacrolimus and prednisone with or without mycophenolate mofetil. The follow-up duration on sirolimus therapy was 8.5 +/- 5.9 months (range: 1 to 22 months). The average dosage of sirolimus was 1.8 +/- 0.5 mg/d at the end of follow-up. The mean trough level of sirolimus was 5.1 +/- 2.1 ng/mL. Sirolimus was effective in 16 (50%) patients while 3 (9.4%) patients improved (serum creatinine [Cr] decrease > 10%) and 13 (40.6%) maintained stable (change of serum Cr within 10%). Sirolimus was effective in 5 (35.7%) patients whose serum Cr was over 3.0 mg/dL but failed to rescue all four patients whose serum Cr was over 4.0 mg/dL. Eleven (68.8%) of 16 responders showed a reduction (29.8% +/- 13.8%) in CNI dosage. The most common adverse events were hyperlipidemia (37.5%), anemia (25%), and diarrhea (21.8%). Twelve patients discontinued sirolimus due to graft failure (4), severe infection (3), stroke related mortality (1), anemia (2), diarrhea (1), and edema (1). In conclusion, sirolimus is effective in 50% of KTx recipients with CAN, especially when the serum Cr is less than 3.0 mg/dL. However, the increased incidence of infection, diarrhea, and hyperlipidemia are of major concern.

Adult↗
PubMed2004

De novo cancer occurrence after renal transplantation: a medical center experience in Taiwan.

INTRODUCTION: Renal transplantation has been advocated as the treatment of choice for end-stage renal disease. Organ transplantation increases the incidence of cancer through unclear mechanisms. A literature review showed that the most common neoplasms are of skin origin, which are uncommon in Eastern people. We reviewed cancer patterns in our renal transplant series. MATERIALS AND METHODS: From July 1981 to December 2002, among 560 renal transplantations performed in this hospital, we retrospectively surveyed cancer incidence, types, and usage of immunosuppressants. RESULTS: Twenty nine cancer cases 5.18% (incidence) included hepatocellular carcinoma (HCC) as the highest mortality rate (9 of 13 cases). Eight of these 13 cases were hepatitis B carriers. All four hepatitis C carriers expired three of them with unresectable multinodular tumors at diagnosis in Posttransplantation lymphoproliferative disorder (PTLD) was the second most common cancer (seven cases); all but one survived with reduced doses of or changes in immunosuppressants. No skin cancer other than four Kaposi's sarcomas with skin manifestations was detected in our series. DISCUSSIONS: HCC was the main cancer in our series. Accepting hepatitis B carriers as candidates for renal recipients and donors may be one of the causes. PTLD was the second most common cancer, while there were no skin cancers.

Adult↗
PubMed2004

Risks and quality-of-life changes in living kidney donors.

INTRODUCTION: Although the benefits of living donor organs for recipients are well documented, the risks and quality-of-life changes in living kidney donors are seldom reported. METHODS: From July 1992 to June 2002, all living kidney donors underwent regular follow-up at our hospital. The MOS 36-item short-form health survey (SF-36), a standardized questionnaire to measure quality of life, was used in this study. Furthermore, donor renal function and associate complications were assessed. RESULTS: Seventeen donors answered the questionnaire, including eight men and nine women of mean age of 41 years (range = 25 to 56). No perioperative mortality was noted. No proteinuria or hematuria was found during long-term follow-up. The mean serum creatinine level was 0.95 +/- 0.22 mg/dL before the operation. The postoperative mean serum creatinine levels at 6 months, 1 year, and 3 years were 1.22 +/- 0.34, 1.19 +/- 0.20, and 1.29 +/- 0.21 mg/dL, respectively. Two cases underwent scar revision and one complained long-term wound pain for more than 1 year. One donor became depressed because of graft failure in her son. The SF-36 scores were 84.4 +/- 4.4 (physical function), 84.0 +/- 4.7 (role-physical), 78.4 +/- 8.0 (body pain), 81.5 +/- 5.9 (general health), 83.2 +/- 3.7 (vitality), 83.9 +/- 5.9 (social functioning), 79.9 +/- 4.1 (role-emotional), and 78.6 +/- 2.3 (mental health), respectively. CONCLUSION: The quality-of-life changes and risks after donation are low; most donors are concerned about cosmetic problems and pain-related scar formation.

Adult↗