Biomedical subjects

Wen-Chieh Chen

Publications and source records attributed to Wen-Chieh Chen.

6 recordsLinked to original sources

PubMed2006

Genetic susceptibility to carbamazepine-induced cutaneous adverse drug reactions.

The anticonvulsant carbamazepine (CBZ) frequently causes cutaneous adverse drug reactions (cADRs), including maculopapular eruption (MPE), hypersensitivity syndrome (HSS), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). We reported that SJS/TEN caused by CBZ is strongly associated with the HLA-B*1502 gene in Han Chinese. Here, we extended our genetic study to different types of CBZ-cADRs (91 patients, including 60 patients with SJS/TEN, 13 patients with hypersensitivity syndrome and 18 with maculopapular exanthema versus 144 tolerant controls). We used MALDI-TOF mass spectrometry to screen the genetic association of 278 single nucleotide polymorphisms (SNPs), which cover the major histocompatibility complex (MHC) region, tumor necrosis factor-alpha, heat shock protein and CBZ-metabolic enzymes, including CYP3A4, 2B6, 2C8, 2C9, 1A2 and epoxide hydrolase 1. In addition, we genotyped 20 microsatellites in the MHC region and performed HLA-typing to construct the recombinant map. We narrowed the susceptibility locus for CBZ-SJS/TEN to within 86 kb flanking the HLA-B gene on the extended B*1502 haplotype, and confirmed the association of B*1502 with SJS/TEN [Pc=1.6x10, odds ratio (OR)=1357; 95% confidence interval (CI)=193.4-8838.3]. By contrast to CBZ-SJS/TEN, HLA-B*1502 association was not observed in the MPE or HSS groups: MPE was associated with SNPs in the HLA-E region and a nearby allele, HLA-A*3101 (Pc=2.2x10, OR=17.5; 95% CI=4.6-66.5), and HSS with SNPs in the motilin gene (Pc=0.0064, OR=7.11; 95% CI=3.1-16.5) located terminal to the MHC class II genes. No SNPs in genes involved in CBZ metabolism were associated with CBZ-induced cADRs. Our data suggest that HLA-B*1502 could contribute to the pathogenesis of CBZ-SJS/TEN, and that genetic susceptibility to CBZ-induced cADRs is phenotype-specific.

Anticonvulsants↗

PubMed2005

Data mining of tree-based models to analyze freeway accident frequency.

INTRODUCTION: Statistical models, such as Poisson or negative binomial regression models, have been employed to analyze vehicle accident frequency for many years. However, these models have their own model assumptions and pre-defined underlying relationship between dependent and independent variables. If these assumptions are violated, the model could lead to erroneous estimation of accident likelihood. Classification and Regression Tree (CART), one of the most widely applied data mining techniques, has been commonly employed in business administration, industry, and engineering. CART does not require any pre-defined underlying relationship between target (dependent) variable and predictors (independent variables) and has been shown to be a powerful tool, particularly for dealing with prediction and classification problems. METHOD: This study collected the 2001-2002 accident data of National Freeway 1 in Taiwan. A CART model and a negative binomial regression model were developed to establish the empirical relationship between traffic accidents and highway geometric variables, traffic characteristics, and environmental factors. RESULTS: The CART findings indicated that the average daily traffic volume and precipitation variables were the key determinants for freeway accident frequencies. By comparing the prediction performance between the CART and the negative binomial regression models, this study demonstrates that CART is a good alternative method for analyzing freeway accident frequencies. IMPACT ON INDUSTRY: By comparing the prediction performance between the CART and the negative binomial regression models, this study demonstrates that CART is a good alternative method for analyzing freeway accident frequencies.

Accidents, Traffic↗

PubMed2005

Caldimonas taiwanensis sp. nov., a amylase producing bacterium isolated from a hot spring.

During screening for amylase-producing bacteria, a strain designated OnlT was isolated from a hot spring located in Pingtung area, which is near the very southern part of Taiwan. Cells of this organism were Gram-negative rods motile by means of a single polar flagellum. Optimum conditions for growth were 55 degrees C and pH 7. Strain On1(T) grew well in minimal medium containing starch as the sole carbon source, and its extracellular products expressed amylase activity. The 16S rRNA gene sequence analysis indicates that strain On1(T) is a member of beta-Proteobacteria. On the basis of a phylogenetic analysis of 16S rDNA sequences, DNA-DNA similarity data, physiological and biochemical characteristics, as well as fatty acid compositions, the organism belonged to the genus Caldimonas and represented a novel species within this genus. The predominant cellular fatty acids of strain On1(T) were 16:0 (about 30%), 18:1 omega 7c (about 20%) and summed feature 3 (16:1 omega 7c or 15:0 iso 2OH or both [about 31%]). Its DNA base ratio was 65.9 mol% G + C. We propose to classify strain On1(T) (= BCRC 17405T = LMG 22827T) as Caldimonas taiwanensis sp. nov.

Amylases↗

PubMed2005

Leprosy in the Department of Dermatology, Chang Gung Memorial Hospital at Kaohsiung from 1988 to 2004: a clinical and histopathologic study of 13 cases.

BACKGROUND: Leprosy has long been in Taiwan, but it has never been eradicated. Incidental cases are easily overlooked nowadays because most younger dermatologists are unfamiliar with this disease. METHODS: We review and analyze 13 cases diagnosed as leprosy at the Department of Dermatology, Chang Gung Memorial Hospital at Kaohsiung from 1988 to 2004, all of which were histopathologically proven. RESULTS: The ages of the 13 recruited patients ranged from 31 to 73 (mean, 58.6) years, without a gender preference (male: female, 7:6). Two male patients were under 40 years old; one was a foreign worker from Thailand and the other was a local person in Penghu working as the chief officer on a fishing boat. The most-common clinical subtype was lepromatous leprosy (5/13), followed by borderline lepromatous leprosy, borderline tuberculoid leprosy, and tuberculoid leprosy (each 2/13), and then borderline leprosy and indeterminate leprosy (each 1/13). The initial clinical impression before the histopathological diagnosis included granuloma annulare, generalized eczema, lymphoma, syphilis, papular urticaria, cutaneous tuberculous infection, Sweet's syndrome, erythema annulare centrifugum, and hematoma. Most of these patients only received irregular treatment after the diagnosis was made and were soon lost to follow-up. CONCLUSIONS: With increasing numbers of foreign workers and immigrants living in Taiwan in recent years, leprosy seems to have become a challenging diagnosis for younger dermatologists. Dermatologists should keep this ancient disease in mind and not overlook it. Because of the necessity of prolonged medication, complete treatment and long-term follow-up of leprosy cases will remain a major problem in public health.

Adult↗

PubMed2004

Acute generalized exanthematous pustulosis caused by celecoxib.

Acute generalized exanthematous pustulosis (AGEP) is a rapidly evolving, febrile, widespread, non-follicular pustular eruption mainly provoked by drugs. Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor containing a sulfonamide substitute, is now clinically widely used due to its advantage of lower rate of gastrointestinal irritation. We report a case of AGEP in a 61-year-old woman who presented with fever, widespread maculopapules, vesicles, bullae, tiny pustules and leukocytosis soon after the ingestion of celecoxib. The condition resolved rapidly within 10 days. AGEP was diagnosed based on clinical and histopathological findings. Skin patch testing showed positive reaction to 1% celecoxib without cross-reactivity to 1% sulfamethoxazole-trimethoprim.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2002

Finasteride in the treatment of Taiwanese men with androgenetic alopecia: a 12-month open-label study.

Finasteride 1 mg/day is effective in the treatment of androgenetic alopecia (AGA). Our open-label study assessed the efficacy and safety of finasteride for the treatment of Taiwanese men with AGA. We enrolled 34 Taiwanese men (aged 18-40 yr) with AGA of modified Norwood/Hamilton scale (MNHS) grade II-V. In investigator assessments at 12 months, five of 21 subjects (23.8%) had two-grade improvement in MNHS grade and 12 of 21 subjects (57.1%) had one-grade improvement; the others remained at the same grade. In global photographic evaluation, five of 31 subjects (15.1%) had observable hair growth at 6 months and 11 of 21 subjects (52.4%) had observable hair growth at 12 months. Patient self-assessment of hair growth was favorable across all questions in the treatment course, more significantly at 12 months than at 6 months; nine of 21 subjects (42.9%) were satisfied with their overall appearance at 12 months. Serum prostate specific antigen levels had decreased by 23.4% at 12 months. Adverse effects, including abnormal liver function (5/34), were minimal, and the causal relationship with finasteride could not be established. Thus, in Taiwanese men with AGA, finasteride 1 mg/day for 1 year slowed the progression of hair loss and increased hair growth.

Adolescent↗