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Yi-Ju Chen

Publications and source records attributed to Yi-Ju Chen.

14 recordsLinked to original sources
PubMed2007

Predicting factors of interstitial lung disease in dermatomyositis and polymyositis.

The aim of this study was to define the predicting factors and evaluate the prognosis of interstitial lung disease in dermatomyositis/polymyositis. For the period 1995-2005, we retrospectively reviewed the clinical information and laboratory data of 56 patients who were diagnosed as definite and probable dermatomyositis and polymyositis. Interstitial lung disease is common (41.9%) in these patients. Dyspnoea and cough were the two most common initial presentations. Anti-Jo1 antibody was more common in those with interstitial lung disease. Univariate and multivariate analyses identified primary idiopathic dermatomyositis subtype, cough and dyspnoea at onset to be the three independent clinical predicting factors of interstitial lung disease. High serum lactate dehydrogenase level (>400 U/l) was inversely associated with development of interstitial lung disease (OR 0.088, p=0.031). Serum lactate dehydrogenase level and presence of anti-Jo1 antibody can serve as laboratory indicators of lung complications. Patients with malignancy and older age at onset (more than 60 years) had poorer prognosis for dermatomyositis/polymyositis (p=0.047 and p=0.035, respectively). Interstitial lung disease did not affect the survival of dermatomyositis/polymyositis patients.

Adult↗
PubMed2006

Elevated plasma osteopontin associated with gastric cancer development, invasion and survival.

OBJECTIVE: Osteopontin (OPN) has been found to be valuable in diagnosis and predicting the prognosis of a variety of malignancies. The aims of the present study are to evaluate the usefulness of plasma OPN level for predicting gastric cancer development, invasion and survival. PATIENTS AND METHODS: One hundred and thirty two gastric cancer patients and 93 healthy controls were enrolled. Real-time quantitative reverse-transcription polymerase chain reaction and immunohistochemical staining were used to detect OPN expression in gastric cancer tissues. Plasma levels of OPN were measured by enzyme-linked immunosorbent assay. Plasma OPN levels were compared with gastric cancer development, clinicopathological features and outcomes. RESULTS: Expression of OPN mRNA was significantly higher in gastric cancer tissues compared with non-tumour tissues. Most OPN immunoactivity was localised to cancer cells. The median plasma OPN level was significantly higher in patients than in controls (p<0.0001), and significantly higher in patients with advanced stages, serosal invasion, lymph node metastasis, lymphatic invasion, venous invasion and liver metastasis. Logistic regression showed that high plasma OPN level (greater than 67.3 ng/ml) is significantly associated with advanced stages, serosal invasion, lymph node metastasis, lymphatic invasion, venous invasion and liver metastasis. Plasma OPN level demonstrated significant association with patient survival (p<0.0001), especially in the subgroups with invasive phenotypes. On Cox multivariate analysis, elevated plasma OPN level was an independent risk factor for poor survival (p<0.0001). CONCLUSIONS: Elevated plasma OPN level is significantly associated with gastric cancer development, invasive phenotypes and survival. Plasma OPN level may have potential usefulness as a diagnostic and prognostic factor for gastric cancer.

Adenocarcinoma↗
PubMed2005

Genome sequencing in microfabricated high-density picolitre reactors.

The proliferation of large-scale DNA-sequencing projects in recent years has driven a search for alternative methods to reduce time and cost. Here we describe a scalable, highly parallel sequencing system with raw throughput significantly greater than that of state-of-the-art capillary electrophoresis instruments. The apparatus uses a novel fibre-optic slide of individual wells and is able to sequence 25 million bases, at 99% or better accuracy, in one four-hour run. To achieve an approximately 100-fold increase in throughput over current Sanger sequencing technology, we have developed an emulsion method for DNA amplification and an instrument for sequencing by synthesis using a pyrosequencing protocol optimized for solid support and picolitre-scale volumes. Here we show the utility, throughput, accuracy and robustness of this system by shotgun sequencing and de novo assembly of the Mycoplasma genitalium genome with 96% coverage at 99.96% accuracy in one run of the machine.

Electrophoresis, Capillary↗
PubMed2005

Novel and established potassium channel openers stimulate hair growth in vitro: implications for their modes of action in hair follicles.

Although ATP-sensitive potassium (K(ATP)) channel openers, e.g., minoxidil and diazoxide, can induce hair growth, their mechanisms require clarification. Improved drugs are needed clinically. but the absence of a good bioassay hampers research. K(ATP) channels from various tissues contain subtypes of the regulatory sulfonylurea receptor, SUR, and pore-forming, K(+) inward rectifier subunits, Kir6.X, giving differing sensitivities to regulators. Therefore, the in vitro effects of established potassium channel openers and inhibitors (tolbutamide and glibenclamide), plus a novel, selective Kir6.2/SUR1 opener, NNC 55-0118, were assessed on deer hair follicle growth in serum-free median without streptomycin. Minoxidil (0.1-100 microM, p<0.001), NNC 55-0118 (1 mM, p<0.01; 0.1, 10, 100 microM, p<0.001), and diazoxide (10 microM, p<0.01) increased growth. Tolbutamide (1 mM) inhibited growth (p<0.001) and abolished the effect of 10 microM minoxidil, diazoxide and NNC 55-0118; glibenclamide (10 microM) had no effect, but prevented stimulation by 10 microM minoxidil. Phenol red stimulated growth (p<0.001), but channel modulator responses remained unaltered. Thus, deer follicles offer a practical, ethically advantageous in vitro bioassay that reflects clinical responses in vivo. The results indicate direct actions of K(ATP) channel modulators within hair follicles via two types of channels, with SUR 1 and SUR 2, probably SUR2B, sulfonylurea receptors.

Animals↗
PubMed2005

No correlation between BRAFV600E mutation and clinicopathological features of papillary thyroid carcinomas in Taiwan.

OBJECTIVE: Genetic alterations in four oncogenes, namely RAS point mutations, RET rearrangements (RET/PTC), NTRK1 rearrangements (TRK) and BRAF point mutations have been identified in human papillary thyroid carcinomas (PTCs). These oncogenes act along the RET/PTC(TRK)-RAS-BRAF-MEK-MAPK kinase pathway, mediating a number of cellular fates including growth, proliferation and survival in thyroid cells. In this study, we analysed mutations of BRAF in a cohort of PTCs. METHODS: To screen for BRAF mutations, the genomic DNA of 105 PTCs were amplified by polymerase chain reaction (PCR) with primers flanking exon 15 and PCR products were directly sequenced with an automatic sequencer. These results, together with data from our previous studies on RAS, RET rearrangements and NTRK1 rearrangements in the same tumours, were compared to determine their individual significance in the pathogenesis of PTCs in Taiwan. RESULTS: BRAF mutations were detected in 49 of 105 (47%) tumour samples. All mutations involved a thymine-to-adenine transversion at nucleotide 1799 and were heterozygous. There was no overlap between papillary carcinomas harbouring RET rearrangements, NTRK1 rearrangements and BRAF mutations. In this cohort, correlation between BRAF mutations and various clinicopathological parameters in 101 papillary carcinomas did not reveal any association with age at diagnosis, sex, tumour size, histological variants of PTC, multicentricity, cervical lymph node metastases, extrathyroidal invasion, distant metastases and clinical stage. CONCLUSIONS: BRAFV600E mutation is the most prevalent oncogene in PTCs in Taiwan. Our data did not suggest that BRAFV600E mutation could be a potentially useful marker of prognosis in patients with papillary carcinomas in the population studied.

Adult↗
PubMed2005

Forkhead box M1 regulates the transcriptional network of genes essential for mitotic progression and genes encoding the SCF (Skp2-Cks1) ubiquitin ligase.

The Forkhead box m1 (Foxm1) gene is critical for G(1)/S transition and essential for mitotic progression. However, the transcriptional mechanisms downstream of FoxM1 that control these cell cycle events remain to be determined. Here, we show that both early-passage Foxm1(-)(/)(-) mouse embryonic fibroblasts (MEFs) and human osteosarcoma U2OS cells depleted of FoxM1 protein by small interfering RNA fail to grow in culture due to a mitotic block and accumulate nuclear levels of cyclin-dependent kinase inhibitor (CDKI) proteins p21(Cip1) and p27(Kip1). Using quantitative chromatin immunoprecipitation and expression assays, we show that FoxM1 is essential for transcription of the mitotic regulatory genes Cdc25B, Aurora B kinase, survivin, centromere protein A (CENPA), and CENPB. We also identify the mechanism by which FoxM1 deficiency causes elevated nuclear levels of the CDKI proteins p21(Cip1) and p27(Kip1). We provide evidence that FoxM1 is essential for transcription of Skp2 and Cks1, which are specificity subunits of the Skp1-Cullin 1-F-box (SCF) ubiquitin ligase complex that targets these CDKI proteins for degradation during the G(1)/S transition. Moreover, early-passage Foxm1(-)(/)(-) MEFs display premature senescence as evidenced by high expression of the senescence-associated beta-galactosidase, p19(ARF), and p16(INK4A) proteins. Taken together, these results demonstrate that FoxM1 regulates transcription of cell cycle genes critical for progression into S-phase and mitosis.

Animals↗
PubMed2004

Ovarian fibroma in a 7-month-old infant: a case report and review of the literature.

Ovarian fibroma rarely occurs in prepubertal girls. We report an ovarian fibroma in a 7-month-old female infant presenting as a right abdominal mass. The tumour was composed of oval-to-spindle cells forming interlacing fascicles and intermingling with collagen fibres. Immunohistochemically, the tumour cells were weakly positive for estrogen receptor and progesterone receptor but negative for inhibin. To the best of our knowledge, this is the youngest case of ovarian fibroma up-to-date in the English literature. Because Gorlin's syndrome was not present in the patient's family, other factors such as germline or somatic mutations may predispose the occurrence of this ovarian fibroma in infancy.

Basal Cell Nevus Syndrome↗
PubMed2003

Effect of caloric restriction on Hprt lymphocyte mutation in aging rats.

Caloric restriction (CR) reduces tumor incidence and retards aging in laboratory animals, including non-human primates. Because of the relationships among mutation, disease susceptibility, and aging, we investigated whether or not CR affects the accumulation of somatic cell mutations in aging animals. Starting at approximately 2 months of age, male CD rats (Harlan Sprague-Dawley-derived) were placed on different levels of dietary intake: ad libitum (AL) feeding, and 90% (10% CR), 75% (25% CR) and 60% (40% CR) of the total calories consumed by AL animals. At 3, 6, 12, and 24 months after the beginning of CR, Hprt mutant frequencies (MFs) were determined. The MFs measured in spleen lymphocytes from AL and CR rats sacrificed at 3 months of dietary restriction were similar for all dietary groups. However, the MFs at 6, 12, and 24 months of CR were significantly higher in AL-fed rats compared with animals on 40% CR: (4.5+/-0.4)x10(-6) versus (3.3+/-0.3)x10(-6) (P=0.032) in 6 months CR rats; (10.3+/-2.3)x10(-6) versus (7.3+/-1.2)x10(-6) in 12 months CR rats (P=0.04), and (18.3+/-3.2)x10(-6) versus (7.8+/-1.0)x10(-6) (P=0.001) in 24 months CR rats. In addition, rats receiving 25% CR for 24 months had a MF, (10.7+/-2.0)x10(-6), between the 40% CR and AL rats. Multiplex PCR of the Hprt gene in mutant clones from 12 and 24 months 40% CR rats and the corresponding AL rats detected deletions in 42% of CR mutants and 19% of AL mutants. Because of the difference in Hprt MF in the two groups, the estimated MF associated with deletions in CR rats was similar to the deletion MF in AL rats. This observation implies that the lower MF in CR rats is due to a reduction in smaller Hprt mutations (i.e. base substitutions and frameshifts). The pattern of smaller Hprt mutations from AL rats suggests that many were produced by reactive oxygen species (ROS). The results indicate that CR reduces the accumulation of spontaneous somatic cell mutation in aging rats, especially those caused by base substitutions and frameshifts.

Aging↗
PubMed2003

Testing for differentially expressed genes with microarray data.

This paper compares the type I error and power of the one- and two-sample t-tests, and the one- and two-sample permutation tests for detecting differences in gene expression between two microarray samples with replicates using Monte Carlo simulations. When data are generated from a normal distribution, type I errors and powers of the one-sample parametric t-test and one-sample permutation test are very close, as are the two-sample t-test and two-sample permutation test, provided that the number of replicates is adequate. When data are generated from a t-distribution, the permutation tests outperform the corresponding parametric tests if the number of replicates is at least five. For data from a two-color dye swap experiment, the one-sample test appears to perform better than the two-sample test since expression measurements for control and treatment samples from the same spot are correlated. For data from independent samples, such as the one-channel array or two-channel array experiment using reference design, the two-sample t-tests appear more powerful than the one-sample t-tests.

DNA, Complementary↗
PubMed2003

Normalization methods for analysis of microarray gene-expression data.

This paper investigates subset normalization to adjust for location biases (e.g., splotches) combined with global normalization for intensity biases (e.g., saturation). A data set from a toxicogenomic experiment using the same control and the same treated sample hybridized to six different microarrays is used to contrast the different normalization methods. Simple t-tests were used to compare two samples for dye effects and for treatment effects. The numbers of genes that reproducibly showed significant p-values for the unnormalized data and normalized data from different methods were evaluated for assessment of different normalization methods. The one-sample t-statistic of the ratio of red to green samples was used to test for dye effects using only control data. For treatment effects, in addition to the one-sample t-test of the ratio of the treated to control samples, the two-sample t-test for testing the difference between treated and control samples was also used to compare the two approaches. The method that combines a subset approach (median or lowess fit) for location adjustment with a global lowess fit for intensity adjustment appears to perform well.

Bias↗
PubMed2002

Molecular characterization of angiogenic properties of human oral squamous cell carcinoma cells.

Little is known about the specificity of angiogenic properties of oral cancer cells and the possible mechanisms. Stimulatory effects on proliferation and migration of human umbilical vein endothelial cells (HUVEC) characterized the angiogenic properties of oral cancer cells but not normal oral keratinocytes (NOK). ELISA found the presence of vascular endothelial growth factors (VEGF) both in the tested oral cancer cells and NOK. Attenuation of the proangiogenic effects by neutralizing VEGF antibodies suggests VEGF play a key role in the acquisition of the angiogenic phenotype in oral cancer cells. Western blotting of p53 and murine double mutant 2 (Mdm2) together with p53 DNA sequencing analysis indicate that p53 function loss by mutation or overexpression of Mdm2 occurred in all tested oral cancer cells regardless of their etiology. In summary, the angiogenic property of oral cancer cells is mediated by many factors in addition to VEGF and the functional status of p53.

Carcinoma, Squamous Cell↗
PubMed1999

Contacting and forming singularities: Distinguishing examples.

A thin film bridge breaks in a way that starts at one equilibrium state and ends at another equilibrium state. The dynamical trajectory that carries it from connected to disconnected provides rare evidence regarding the singularity of passage through topological change. This nonequilibrium trajectory, called a "forming" flow, is discussed in an attempt to frame it within the larger class of singularities for which bounding surfaces do not remain material surfaces. As a contrast, the weaker "contacting" singularity is illustrated by a stagnation flow where material points reach the stagnation point in finite time. A classification scheme based on pathology of the nonunique Lagrangian motions is suggested. New results for the disconnection example include healing of surgery in post-disconnection simulations, different dynamical scalings of the just-disconnected components and a comparison of post-disconnection simulation to experiment. (c) 1999 American Institute of Physics.

Journal Article↗
PubMedDate not supplied

Influence of COX-2 and local cytokine expressions in gastric ulcer mucosa by H. pylori and NSAID.

BACKGROUND/AIMS: H. pylori and NSAIDs are the two most important pathogenic factors in gastric ulcer. NSAIDs and H. pylori share common pathogenic characteristics, but have different effects in modulating COX-2 and local cytokines in gastric ulcer mucosa. This study was designed to explore the influence of COX-2 and local cytokine expressions in gastric ulcer mucosa induced by H. pylori infection and NSAID use. METHODOLOGY: Twenty-three patients were recruited. Sixteen subjects were infected with H. pylori. Fifteen patients used NSAIDs. Gastric biopsy specimens were obtained by endoscopy. COX-2 and local cytokine mRNA expressions were assessed by real-time RT-PCR. RESULTS: COX-2 and local cytokines were over-expressed in gastric ulcer and were positively intercorrelated. H. pylori did not alter COX-2 and local cytokine expressions in gastric ulcer, but induced IL-8 and COX-2 in antral mucosa. NSAIDs inhibited COX-2 expression in gastric ulcer, but had no effect on other local cytokines. COX-2 inhibition by NSAIDs in gastric ulcer was compatible with the findings that NSAIDs delayed gastric ulcer healing. CONCLUSIONS: H. pylori increased IL-8 and COX-2 in the antral mucosa, but did not influence COX-2 and local cytokines in gastric ulcer. NSAIDs inhibited COX-2 in gastric ulcer and delayed gastric ulcer healing.

Adult↗