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Biomedical subjects

Y-C Chen

Publications and source records attributed to Y-C Chen.

At least 19 recordsLinked to original sources
PubMed2007

Nuclear HBcAg and histology activity index as independent predictors of the expression of singly spliced HBV-RNA.

Although hepatitis B virus (HBV) RNA splicing has been reported by many researchers, the clinical significance of this event remains illusive. The present study was designed to investigate the clinical roles of singly spliced HBV-RNA. Liver biopsy tissues obtained from 32 consecutive patients were subjected to reverse transcriptase-polymerase chain reaction for the detection of singly spliced and unspliced HBV-RNA. Stepwise linear regression model was used to estimate the ratio of singly spliced to unspliced (S/US) HBV-RNA in the presence of the following variables: age, gender, aspartate aminotransferase, alanine aminotransferase, total bilirubin, alpha-foetoprotein, status of HBV e antigen (HBeAg), status of antibody to HBeAg, HBV-DNA, histology activity index (HAI), fibrotic score, grade of cytoplasmic HBV core antigen (HBcAg), grade of nuclear HBcAg, genotype, status of precore-stop-mutation, basal core promoter mutation, previous lamivudine therapy and superinfection by other hepatitis viruses. The results showed that HAI (beta = -0.2616; P = 0.011) and grade of nuclear HBcAg expression (beta = 0.5599; P =0.0067) were two independent predictors for the expression of singly spliced HBV-RNA. Further categorical analysis showed that patients with HAI score or=2 have significantly higher S/US ratios. In conclusion, nuclear HBcAg and HAI are two independent predictors for the expression of singly spliced HBV-RNA.

Adult↗
PubMed2006

Suberosin inhibits proliferation of human peripheral blood mononuclear cells through the modulation of the transcription factors NF-AT and NF-kappaB.

BACKGROUND AND PURPOSE: Extracts of Plumbago zeylanica containing suberosin exhibit anti-inflammatory activity. We purified suberosin from such extracts and studied its effects on a set of key regulatory events in the proliferation of human peripheral blood mononuclear cells (PBMC) stimulated by phytohemagglutinin (PHA). EXPERIMENTAL APPROACH: Proliferation of PBMC in culture was measured by uptake of 3H-thymidine; production of cytokines and cyclins by Western blotting and RT-PCR. Transcription factors NF-AT and NF-kappaB were assayed by immunocytochemistry and EMSA. KEY RESULTS: Suberosin suppressed PHA-induced PBMC proliferation and arrested cell cycle progression from the G1 transition to the S phase. Suberosin suppressed, in activated PBMC, transcripts of interleukin-2 (IL-2), interferon-gamma (IFN-gamma), and cyclins D3, E, A, and B. DNA binding activity and nuclear translocation of NF-AT and NF-kappaB induced by PHA were blocked by suberosin. Suberosin decreased the rise in intracellular Ca2+ concentration ([Ca2+]i) in PBMC stimulated with PHA. Suberosin did not affect phosphorylation of p38 and JNK but did reduce activation of ERK in PHA-treated PBMC. Pharmacological inhibitors of NF-kappaB, NF-AT, and ERK decreased expression of mRNA for the cyclins, IL-2, and IFN-gamma and cell proliferation in PBMC activated by PHA. CONCLUSIONS AND IMPLICATIONS: The inhibitory effects of suberosin on PHA-induced PBMC proliferation, were mediated, at least in part, through reduction of [Ca2+]i, ERK, NF-AT, and NF-kappaB activation, and early gene expression in PBMC including cyclins and cytokines, and arrest of cell cycle progression in the cells. Our observations provide an explanation for the anti-inflammatory activity of P. zeylanica.

Anti-Inflammatory Agents↗
PubMed2006

Mechanoelectrical feedback regulates the arrhythmogenic activity of pulmonary veins.

BACKGROUND: Atrial fibrillation is commonly associated with dilated pulmonary veins. Stretch has been shown to have mechano-electrical effects. OBJECTIVE: To investigate whether stretch can increase the arrhythmogenic activity of the pulmonary veins. METHODS: The transmembrane action potentials were recorded from rabbit pulmonary veins before and after stretch (100 and 300 mg). Gadolinium and streptomycin (stretch-activated ion channel blockers) were each perfused into the pulmonary veins under a 300-mg stretch. RESULTS: Stretch (0, 100 and 300 mg) force dependently increased the incidence of spontaneous activity (22%, 48% and 83%; p<0.05), mean (standard deviation (SD)) firing rates of spontaneous activity (1.7 (0.2), 2.1 (0.3) and 3 (0.2) Hz; p<0.05) and incidence of early post-depolarisations (9%, 26% and 61%; p<0.05) and delayed post-depolarisations (0%, 4% and 30%; p<0.05) in 23 pulmonary veins. In the seven preparations with spontaneous activity after the 300-mg stretch, gadolinium (1, 3 and 10 mumol/l) decreased the incidence of spontaneous activity by 43%, 29% and 14%, respectively (p<0.05), and decreased the firing rate from 2.9 (0.1) Hz to 0.8 (0.4), 0.3 (0.1) and 0.1 (0.1) Hz, respectively (p<0.05). Streptomycin (10 and 40 mumol/l) decreased the incidence of spontaneous activity by 71% and 29%, respectively (p<0.05), and decreased the firing rate from 2.9 (0.1) Hz to 1.6 (0.4) and 0.5 (0.3) Hz, respectively (p<0.05). CONCLUSION: Stretch is an important factor in the electrical activity of the pulmonary vein. Stretch-induced arrhythmogenic activity of the pulmonary vein may contribute to the genesis of atrial fibrillation.

Action Potentials↗
PubMed2006

Clinical significance of anti-GM-CSF antibodies in idiopathic pulmonary alveolar proteinosis.

BACKGROUND: The role of anti-granulocyte-macrophage colony stimulating factor (GM-CSF) antibodies as a diagnostic marker in idiopathic pulmonary alveolar proteinosis (iPAP) remains unclear. METHODS: Anti-GM-CSF antibodies were detected in blood and bronchoalveolar lavage fluid (BAL) fluid in 13 patients with iPAP. Three patients with secondary PAP, 35 with other pulmonary disorders, and 10 subjects without lung lesions acted as controls. Blood samples only were obtained from 30 healthy medical personnel. Anti-GM-CSF antibodies were detected using immunoblotting and measured semi-quantitatively by serial dilution or concentration methods. The relationship between antibodies and reported severity indicators for iPAP was analysed. RESULTS: Anti-GM-CSF antibodies could be detected in both blood and BAL fluid samples in 12 of 13 iPAP patients and were undetectable in blood and/or BAL fluid from the other subjects studied. BAL fluid levels of anti-GM-CSF antibodies were highly correlated with the severity indicators for iPAP, including serum lactate dehydrogenase (LDH) levels, arterial oxygen tension, alveolar-arterial oxygen tension difference, (AaPO2), lung carbon monoxide transfer factor, and some lesion scores on chest radiographs and computed tomographic scans. In contrast, blood anti-GM-CSF antibodies were not significantly correlated with the severity indicators evaluated. In addition, patients with iPAP who required subsequent therapeutic lung lavage had significantly higher values of serum LDH, AaPO2, and BAL fluid anti-GM-CSF antibodies, and significantly lower values of PaO2. CONCLUSIONS: In addition to serum LDH levels, PaO2 and AaPO2, BAL fluid levels of anti-GM-CSF antibodies might reflect disease severity in patients with iPAP and predict the need for subsequent therapeutic lung lavage. These findings may expand the role of anti-GM-CSF antibodies in iPAP.

Adolescent↗
PubMed2006

Isolated ocular motor nerve palsy in dural carotid-cavernous sinus fistula.

The incidence of dural carotid-cavernous sinus fistula (DCCF) presenting as isolated ocular motor nerve palsies without congestive ocular features is unknown. We reviewed the DCCF patients in our hospital during the last 10 years to elucidate the clinical and neuroradiological features of DCCF with isolated ocular motor nerve palsy. Eleven amongst the 33 DCCF patients presented isolated ocular motor nerve palsy. All the 11 patients underwent brain CT/CT angiography (CTA) and/or MRI/MR angiography (MRA), before the digital subtraction angiography (DSA). The compromised nerves were the oculomotor nerve in eight (72.7%), abducens nerve in two (18.2%) and trochlear nerve in one (9.1%). Brain CT and/or CTA were conducted in four patients but all unremarkable. MRI and/or MRA were performed in nine patients and six of them showed compatible findings of DCCF. The diagnoses of DCCFs were confirmed by DSA and all were posterior-draining type. The outcome was good, with a total recovery rate of 54.5% within 12 months. Thirty-three percent (11 of 33) of our DCCF patients presented with isolated ocular motor nerve palsy, which is not uncommon. MRI and MRA are of value in the initial evaluation, but DSA is necessary for the accurate diagnosis and treatment planning.

Abducens Nerve↗
PubMed2006

Prospective cohort study comparing sequential organ failure assessment and acute physiology, age, chronic health evaluation III scoring systems for hospital mortality prediction in critically ill cirrhotic patients.

The aim of the study was to evaluate the usefulness of sequential organ failure assessment (SOFA) and acute physiology, age, chronic health evaluation III (APACHE III) scoring systems obtained on the first day of intensive care unit (ICU) admission in predicting hospital mortality in critically ill cirrhotic patients. The study enrolled 102 cirrhotic patients consecutively admitted to ICU during a 1-year period. Twenty-five demographic, clinical and laboratory variables were analysed as predicators of survival. Information considered necessary to calculate the Child-Pugh, SOFA and APACHE III scores on the first day of ICU admission was also gathered. Overall hospital mortality was 68.6%. Multiple logistic regression analysis revealed that mean arterial pressure, SOFA and APACHE III scores were significantly related to prognosis. Goodness-of-fit was good for the SOFA and APACHE III models. Both predictive models displayed a similar degree of the best Youden index (0.68) and overall correctness (84%) of prediction. The SOFA and APACHE III models displayed good areas under the receiver-operating characteristic curve (0.917 +/- 0.028 and 0.912 +/- 0.029, respectively). Finally, a strong and significant positive correlation exists between SOFA and APACHE III scores for individual patients (r(2) = 0.628, p < 0.001). This investigation confirms the grave prognosis for cirrhotic patients admitted to ICU. Both SOFA and APACHE III scores are excellent tools to predict the hospital mortality in critically ill cirrhotic patients. The overall predictive accuracy of SOFA and APACHE III is superior to that of Child-Pugh system. The role of these scoring systems in describing the dynamic aspects of clinical courses and allocating ICU resources needs to be clarified.

APACHE↗
PubMed2006

The rationale of fever surveillance to identify patients with severe acute respiratory syndrome in Taiwan.

STUDY OBJECTIVE: To establish a predictive scoring system and to determine its effectiveness for severe acute respiratory syndrome (SARS) cases confirmed by RT-PCR in patients with fever. METHODS: A study was conducted of 484 consecutive patients seen in the emergency department (ED) of our tertiary care center during the SARS outbreak in Taiwan. The scoring system was divided into triage and screening station stages. Data were analysed with multivariable and logistic regression analysis. RESULTS: Of 737 patients who presented to our ED for possible SARS from March to June 2003, we enrolled 484 patients with a temperature >38.0 degrees C (>100.3 degrees F) (age >18 years). Dyspnoea, diarrhoea, travel, close contact, hospital exposure, and household history were identified as predictive indicators in the triage stage. The triage score was the total of six items. With a one-point cutoff value, the sensitivity and specificity were 81.8% (18/22) and 73.6% (340/462). Leukocytosis, thrombocytopenia, lymphopenia, and CXR were identified as predictive indicators in the fever screening stage. Screening station scores (the sum of 10 items) consisted of triage scores, white blood cell count, and CXR. With a three-point cutoff value, the sensitivity and specificity were 95.5% (21/22) and 87.2% (403/462). CONCLUSIONS: Syndromic and traditional surveillance play a role in early identification of SARS in an endemic area. The SARS scoring system described is easily applicable and highly effective in screening patients during outbreaks.

Adult↗
PubMed2005

Clinical significance of cytogenetics and interphase fluorescence in situ hybridization analysis in newly diagnosed multiple myeloma in Taiwan.

BACKGROUND: The incidence of multiple myeloma (MM) is lower in Asia than in Western countries. However, it is not known whether cytogenetic abnormalities (CA) characteristic of MM in Asia differ from those documented in the West. PATIENTS AND METHODS: We analyzed CA by conventional cytogenetics (CG) and/or fluorescence in situ hybridization (FISH), assessed their clinical significance in 150 Chinese MM patients and compared our data with that derived from Western countries. RESULTS: CA were detected by CG (CG_CA) in 44 (29.3%) of the 150 patients and by FISH (FISH_CA) in 59 (67%) of the 88 patients studied. Presence of either CG_CA or FISH_CA was associated with a poor prognosis. Patients with CG_CA and hyperdiploid chromosomes, always associated with several trisomies, had a longer survival (median 25 months versus 12 months; P=0.025) in comparison with those with non-hyperdiploid chromosomes, usually associated with a monosomy 13/partial deletion of 13q (Delta13) and a rearrangement of 14q32. A novel recurrent CG_CA, add(19)(p13), was found in four patients: all males with immunoglobulin G/lambda isotypes, extramedullary myeloma at diagnosis and a poor prognosis. Three groups of patients with significantly different survival, CG_Delta13, FISH_Delta13 but without CG_Delta13, and neither CG_Delta13 nor FISH_Delta13 (median 9 versus 15 versus 32 months; P=0.013) were identified. CONCLUSIONS: We conclude that MM CA in our patients are similar to those noted in Western countries, and that combined CG and FISH analysis can predict prognosis. The clinical significance of add(19)(p13) needs to be further investigated.

Aged↗
PubMed2005

Using human plasma supplemented medium to cultivate human bone marrow-derived mesenchymal stem cell and evaluation of its multiple-lineage potential.

The objective of this study was to evaluate the proliferation and the multiple-lineage differentiation capacity when bone marrow mesenchymal stem cells (BMSCs) were cultured short-term in autologous serum/plasma instead of fetal calf serum (FCS). The BMSCs from 12 donors were cultivated individually in 10% autogenic plasma or serum, with or without bFGF and EGF growth factors. Cell proliferation was examined by a Tetrazolium assay (MTT) after passages 1, 3, and 5. A medium supplemented with 10% human plasma or serum was sufficient to propagate BMSCs. However, no significant proliferation was shown when bFGF and EGF (20 ng/mL each) were added into the medium with autologous serum/plasma. We examined, inductions of adipogenesis, osteogenesis, and chondrocytogenesis, as capacities of multiple-lineage differentiation of cultivated BMSCs (passages 8). Differentiation was investigated by both RT-PCR and immunohistochemistry staining (IHC). Qualitative evidence demonstrated the differentiation capacity was preserved in cultivated BMSCs with autologous serum/plasma.

Bone Marrow Cells↗
PubMed2005

Sibutramine improves insulin sensitivity without alteration of serum adiponectin in obese subjects with Type 2 diabetes.

AIM: To evaluate the effect of sibutramine on weight loss, insulin sensitivity and serum adiponectin levels in obese patients with Type 2 diabetes. METHODS: This study is a randomized, double-blind, placebo-controlled parallel comparison study of sibutramine 15 mg/day and placebo. Forty-eight eligible obese patients with Type 2 diabetes (age between 30 and 75 years with body mass index > or = 27 kg/m(2)) were randomly assigned to receive either placebo (n = 24) or sibutramine (15 mg/day) (n = 24) for 6 months. Fifteen subjects in each group underwent meal tests and modified insulin suppression tests before and after 6 months' treatment. RESULTS: After 6 months of sibutramine treatment statistically significant changes from baseline were observed for body weight (85.4 +/- 2.5 vs. 82.9 +/- 2.4 kg, P < 0.005) and body mass index (32.0 +/- 0.7 vs. 31.4 +/- 0.6 kg/m(2), P < 0.05) without a significant alteration of waist-hip ratio (W/H), blood pressure, heart rate, glycaemic parameters or lipid profiles. The steady-state plasma glucose (SSPG) level during the modified insulin suppression test was significantly reduced in the sibutramine group (17.33 +/- 2.92 vs. 14.29 +/- 4.19 mmol/l, P < 0.05) despite similar steady-state plasma insulin (SSPI) concentrations. In addition, serum adiponectin and C-reactive protein (CRP) levels remained unchanged, although modest weight reduction was achieved after sibutramine treatment. There were also no significant correlations between changes in serum adiponectin and reduction of SSPG or body weight. Daily ambient plasma insulin and glucose concentrations in response to a test meal were not significantly different in subjects receiving sibutramine treatment. CONCLUSIONS: We conclude that treatment with sibutramine 15 mg once daily effectively reduces weight and enhances insulin sensitivity without alteration of serum adiponectin levels in obese patients with Type 2 diabetes.

Adiponectin↗
PubMed2005

Extracorporal liver support with molecular adsorbents recirculating system in patients with hepatitis B-associated fulminant hepatic failure.

Hepatitis B virus (HBV) infection is the most prevalent cause of fulminant hepatic failure (FHF) in the Far East. HBV-associated FHF is characterised by rapidly progressive end organ dysfunction/failure and a very poor prognosis. To investigate how molecular adsorbent recirculating system (MARS) treatment impacts multiple organ system function in HBV-associated FHF. Ten consecutive patients were treated with MARS in a period of 12 months. Clinical, biochemical and haemodynamic parameters were assessed before and after MARS. Various disease severity scoring systems including model for end-stage liver disease, APACHE II, APACHE III, sequential organ failure assessment and organ system failure scores were also assessed. There were significant improvements in hepatic encephalopathy grading (p < 0.001), mean arterial pressure (p < 0.001), plasma renin activity (p = 0.027), bilirubin (p < 0.001), ammonia (p = 0.001) and creatinine levels (p < 0.001). There were also significant improvements in all the scoring systems evaluated. Meanwhile, platelet count was significantly decreased (p < 0.001). One patient was successfully bridged to liver transplantation. Three patients were alive at 3 months of follow-up. MARS can improve multiple organ functions in HBV-associated FHF. On the basis of these findings, randomised controlled studies are indicated and justified.

Adult↗
PubMed2005

Comparison of lidocaine and bronchodilator inhalation treatments for cough suppression in patients with chronic obstructive pulmonary disease.

BACKGROUND: This study aimed to assess and compare the effectiveness of lidocaine and bronchodilator inhalation treatments for rapid cough suppression in patients with chronic obstructive pulmonary disease (COPD). METHODS: Prospective comparison study carried out in a tertiary emergency department. Consecutive COPD patients presenting with intractable cough were randomly assigned to receive lidocaine or terbutaline inhalation treatments for cough suppression. Patients with dyspnoea, unstable vital signs, and pneumonia or neoplasm on chest x ray were excluded. A subjective, 10 point questionnaire based cough severity score was used for assessing the outcome. RESULTS: The final study sample included 127 patients (mean (SD) age, 69.2 (12.1) years; 33.1% women) of whom 62 received nebulised lidocaine and 65 nebulised bronchodilator. The cough severity score was significantly reduced one hour after inhalation treatment with both lidocaine and bronchodilator, with no significant difference in efficacy. Common but mild side effects in the lidocaine group included oropharyngeal numbness and bitter taste, and, in the bronchodilator group, tremor and palpitation. Dyspnoea, dizziness, and nausea and vomiting were equally uncommon in both groups. None of these problems caused any of the patients to discontinue their treatments and no allergic reactions were reported. CONCLUSIONS: Both lidocaine and bronchodilator inhalation treatments are equally effective for short term cough suppression in patients with COPD.

Administration, Inhalation↗
PubMed2005

Randomised controlled trial comparing percutaneous radiofrequency thermal ablation, percutaneous ethanol injection, and percutaneous acetic acid injection to treat hepatocellular carcinoma of 3 cm or less.

AIMS: The aim of this study was to compare the outcomes of radiofrequency thermal ablation (RFTA), percutaneous ethanol injection (PEI), and percutaneous acetic acid injection (PAI) in the treatment of hepatocellular carcinoma (HCC). PATIENTS AND METHODS: A total of 187 patients with HCCs of 3 cm or less were randomly assigned to RFTA (n = 62), PEI (n = 62), or PAI (n = 63). Tumour recurrence and survival rates were assessed. RESULTS: One, two, and three year local recurrence rates were 10%, 14%, and 14% in the RFTA group, 16%, 34%, and 34% in the PEI group, and 14%, 31%, and 31% in the PAI group (RFTA v PEI, p = 0.012; RFTA v PAI, p = 0.017). One, two, and three year survival rates were 93%, 81%, and 74% in the RFTA group, 88%, 66%, and 51% in the PEI group, and 90%, 67%, and 53% in the PAI group (RFTA v PEI, p = 0.031; RFTA v PAI, p = 0.038). One, two, and three year cancer free survival rates were 74%, 60%, and 43% in the RFTA group, 70%, 41%, and 21% in the PEI group, and 71%, 43%, and 23% in the PAI group (RFTA v PEI, p = 0.038; RFTA v PAI, p = 0.041). Tumour size, tumour differentiation, and treatment methods (RFTA v PEI and PAI) were significant factors for local recurrence, overall survival, and cancer free survival. Major complications occurred in 4.8% of patients (two with haemothorax, one gastric perforation) in the RFTA group and in none in two other groups (RFTA v PEI and PAI, p = 0.035). CONCLUSIONS: RFTA was superior to PEI and PAI with respect to local recurrence, overall survival, and cancer free survival rates, but RFTA also caused more major complications.

Acetic Acid↗
PubMed2004

Partonic calculation of the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer.

We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer through the scattering off a parton in the proton. We relate the two-photon exchange amplitude to the generalized parton distributions which appear in hard exclusive processes. We find that when taking the polarization transfer determinations of the form factors as input, adding in the 2-photon correction does reproduce the Rosenbluth cross sections.

Journal Article↗
PubMed2004

Are current-induced forces conservative?

The expression for the force on an ion in the presence of current can be derived from first principles without any assumption about its conservative character. However, energy functionals have been constructed that indicate that this force can be written as the derivative of a potential. On the other hand, there exist specific arguments that strongly suggest the contrary. We propose physical mechanisms that invalidate such arguments and demonstrate their existence with first-principles calculations. While our results do not constitute a formal resolution to the fundamental question of whether current-induced forces are conservative, they represent a substantial step forward in this direction.

Journal Article↗
PubMed2004

Control of vancomycin-resistant enterococci in a hospital: a five-year experience in a Taiwanese teaching hospital.

In order to prevent transmission of hospital-acquired vancomycin-resistant enterococci (VRE), the infection control team (ICT) of the National Taiwan University Hospital (NTUH) introduced practical guidelines from January 1997 to June 2000. All patients at NTUH found to be infected or colonized with VRE were placed in strict contact and cohort isolation. Surveillance cultures were obtained from other patients in close proximity in order to determine any spread of VRE. If identified, these patients were also placed in contact and cohort isolation, and their isolates were subjected to antimicrobial susceptibility testing and molecular typing by pulsed-field gel electrophoresis. During this period, 20 patients were found to have VRE. Based on typing results, there were three occasions where the same VRE strain had spread between index patients and roommates or patients staying in neighbouring rooms. No further spread occurred after applying strict contact isolation for these patients. The hospital-acquired VRE infection rate was around 0.03 to 0.09 per 1000 discharges during the intervention period. After July 2000, however, members of the ICT did not actively monitor or implement any interventions to control VRE. The rate then increased to 0.20 per 1000 discharges in 2001. This study suggests that interventions for the control of VRE, based on the guidelines from the Hospital Infection Control Practice Advisory Committee, are effective for control of VRE spread. Failure to adhere to these guidelines may result in an increase in hospital-acquired VRE.

Adolescent↗