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Biomedical subjects

W C Tsai

Publications and source records attributed to W C Tsai.

At least 19 recordsLinked to original sources
PubMed2007

Expression of the serine protease, matriptase, in breast ductal carcinoma of Chinese women: correlation with clinicopathological parameters.

Matriptase is a serine protease expressed by cells of surface epithelial origin, including epithelial breast tumor cells. Matriptase cleaves and activates proteins implicated in the progression of cancer and represents a potential prognostic and therapeutic target. The aim of this study was to examine matriptase expression in breast tumors of Chinese women and to identify its clinicopathological correlations. Immunohistochemical analysis of matriptase was performed in tissue microarrays of 251 breast tumors including 30 fibroadenomas, 59 ductal carcinomas in situ (DCIS), 38 grade I invasive ductal carcinomas (IDC), 79 grade II IDC, and 45 grade III IDC. The matriptase scores were significantly higher in the tumors than their non-tumor counterparts (178+/-12 for fibroadenoma; 275+/-11 for DCIS; 299+/-10 for grade I IDC; 251+/-10 for grade II IDC; and 314+/-11 for grade III IDC). In cases of IDC, matriptase scores were significantly correlated with tumor staging and nodal staging. Our findings demonstrate that matriptase is over-expressed in breast ductal carcinoma of Chinese women. It therefore may be a good biomarker for diagnosis and treatment of malignant breast tumors.

Adult↗
PubMed2006

Decreased B cells and IgA-secreting B cells partially explain the high prevalence of IgA deficiency in dialysis patients.

AIMS: We previously reported 2 hemodialysis (HD) patients with recurrent infections and selective immunoglobulin A deficiency (IgAD). We further demonstrated that serum IgA levels were lower and the prevalence of IgAD was higher in uremic patients. The exact mechanisms of IgAD in uremic patients largely remained unclear. In some patients, it was caused by anti-IgA antibody neutralization and subsequent destruction. We performed the present study to survey if there is any defect in IgA production. MATERIALS AND METHODS: 288 patients were initially included for examination of serum immunoglobulins. 16 normal persons, 16 dialysis patients without IgAD, and 12 dialysis patients with IgAD were enrolled after the initial examination. Blood was drawn into heparinized tubes. WBC counts and lymphocyte percentage were examined by a CBC counter. Lymphocytes were separated by the Ficoll-Paque method. Flow cytometry was utilized to isolate the B cell and IgA-secreting B cell after staining with CD 19 phycoerythrin and FITC-conjugated rabbit anti-human IgA antibody. RESULTS: There is no significant difference between WBC counts or total lymphocyte counts of these 3 groups. However, we found a lower percentage of total lymphocyte counts in dialysis patients, either with or without IgAD. The total B cell numbers were lower in dialysis patients with IgAD. In addition, there were fewer IgA-secreting B cells in dialysis patients with IgAD. CONCLUSION: Decreased B cell and IgA-secreting B cell counts are seen in uremic patients with IgAD. This, in turn, indicates that there might be a defect of IgA production in some patients, rather than IgA destruction by anti-IgA antibodies as seen in some other patients. Further study is needed to investigate the mechanisms of decreased B cells and IgA-secreting B cells.

Adult↗
PubMed2005

Replication of association of IL1 gene complex members with ankylosing spondylitis in Taiwanese Chinese.

OBJECTIVE: To test the association of interleukin 1 (IL1) gene family members with ankylosing spondylitis (AS), previously reported in Europid subjects, in an ethnically remote population. METHODS: 200 Taiwanese Chinese AS patients and 200 ethnically matched healthy controls were genotyped for five single nucleotide polymorphisms (SNPs) and the IL1RN.VNTR, markers previously associated with AS. Allele, genotype, and haplotype frequencies were compared between cases and controls. RESULTS: Association of alleles and genotypes of the markers IL1F10.3, IL1RN.4, and IL1RN.VNTR was observed with AS (p<0.05). Haplotypes of pairs of these markers and of the markers IL1RN.6/1 and IL1RN.6/2 were also significantly associated with AS. The strongest associations observed were with the marker IL1RN.4, and with the two-marker haplotype IL1RN.4-IL1RN.VNTR (both p = 0.004). Strong linkage disequilibrium was observed between all marker pairs except those involving IL1B-511 (D' 0.4 to 0.9, p<0.01). CONCLUSIONS: The IL1 gene cluster is associated with AS in Taiwanese Chinese. This finding provides strong statistical support that the previously observed association of this gene cluster with AS is a true positive finding. These authors contributed equally to the study.

Asian People↗
PubMed2005

Study of undifferentiated spondyloarthropathy among first-degree relatives of ankylosing spondylitis probands.

OBJECTIVE: To estimate in a Chinese population the prevalence of undifferentiated spondyloarthropathy (USpA) among first-degree relatives (FDRs) of ankylosing spondylitis (AS) probands, and to compare the clinical features of familial USpA with those of sporadic USpA. METHODS: The FDRs of two separate cohorts of consecutive AS probands were evaluated for the prevalence of USpA, using the Modified New York criteria and the European Spondylitis Study Group criteria for AS and SpA, respectively. Sporadic USpA and FDRs of non-SpA rheumatic patient probands served as separate controls. RESULTS: Among the 301 FDRs of 102 AS probands, 7.0% were USpA. This was 1000 times higher than the 147 FDRs of 40 non-SpA probands (P = 0.00230). Within the AS families, USpA was less male-dominated than AS (33.3 vs 72.5%) (P = 0.006). The only feature distinguishing familial from sporadic USpA was that the percentages of HLA B27 were 100 and 50%, respectively (P<0.001). CONCLUSION: USpA and AS coexist in the same Chinese families, both being predisposed by HLA B27. In these families, a female gender favours the development of USpA rather than AS. A significant subset of sporadic USpA (HLA B27-negative group) has a different genetic predisposition compared with familial USpA.

Adult↗
PubMed2005

Evaluation of the dose rate distribution for an air-type 60Co irradiation facility.

The dose rate distributions in the 29,000-Ci 60Co irradiation facility in National Tsing Hua University were investigated by measurements and calculations. The dose rate measurements were performed using radiochromic dye films and an Exradin A2 ion chamber mounted on a PC-controlled motorised vertical translation stage. The calculations were made by using the three-dimensional point kernel code QAD-CGGP with detailed source composition and geometry modelling. The scattered gamma rays from the walls of the irradiation cell were also evaluated by using the Monte Carlo code MCNP.

Air↗
PubMed2004

Absolute instabilities in a high-order-mode gyrotron traveling-wave amplifier.

The absolute instability is a subject of considerable physics interest as well as a major source of self-oscillations in the gyrotron traveling-wave amplifier (gyro-TWT). We present a theoretical study of the absolute instabilities in a TE01 mode, fundamental cyclotron harmonic gyro-TWT with distributed wall losses. In this high-order-mode circuit, absolute instabilities arise in a variety of ways, including overdrive of the operating mode, fundamental cyclotron harmonic interactions with lower-order modes, and second cyclotron harmonic interaction with a higher-order mode. The distributed losses, on the other hand, provide an effective means for their stabilization. The combined configuration thus allows a rich display of absolute instability behavior together with the demonstration of its control. We begin with a study of the field profiles of absolute instabilities, which exhibit a range of characteristics depending in large measure upon the sign and magnitude of the synchronous value of the propagation constant. These profiles in turn explain the sensitivity of oscillation thresholds to the beam and circuit parameters. A general recipe for oscillation stabilization has resulted from these studies and its significance to the current TE01 -mode, 94-GHz gyro-TWT experiment at UC Davis is discussed.

Journal Article↗
PubMed2004

HLA-B60 and B61 are strongly associated with ankylosing spondylitis in HLA-B27-negative Taiwan Chinese patients.

OBJECTIVES: Carriage of HLA-B60 has been shown to increase the risk of ankylosing spondylitis (AS) in B27-positive Caucasian patients, but the association in B27-negative cases is less certain. This study assessed HLA class I gene associations in Chinese HLA-B27-negative AS patients. METHODS: Forty-one Chinese HLA-B27-negative AS patients fulfilling the modified New York diagnostic criteria for AS were recruited, and 11 383 HLA-B27-negative blood donors were used for comparison. HLA-A and -B typing was done with the microlymphocytotoxicity assay. RESULTS: Among the B27-negative AS patients, 21 were male and 20 were female. Of HLA-B alleles, only B60 and B61 significantly increased susceptibility to AS in HLA-B27-negative patients (P<0.001). CONCLUSIONS: In Taiwan Chinese, carriage of B60 is increased in HLA-B27-negative AS patients. The association between B61 and HLA-B27-negative AS patients has not been reported previously. Whether the gene involved is HLA-B60 or B61 or another gene in linkage disequilibrium with these genes is unknown.

Adult↗
PubMed2004

Cytochrome p450 1Al gene polymorphisms in patients with psoriatic arthritis.

OBJECTIVE: To investigate the associations of cytochrome p450 1A1 (CYP1A1) gene polymorphisms with susceptibility to psoriatic arthritis in Taiwan. METHODS: CYP1A1 gene polymorphisms were determined in 52 patients with psoriatic arthritis and in 90 healthy controls by polymerase chain reaction/restriction fragment length polymorphism. RESULTS: The genotype frequency of CYP1A1 4889A/G was significantly increased in patients with psoriatic arthritis in comparison with healthy controls. The phenotype frequency of CYP1A1 4889G was also significantly increased in patients with psoriatic arthritis. The genotype frequency of CYP1A1 4887C/A was significantly higher in patients with psoriatic arthritis than in controls. The allele and phenotype frequencies of 4887A were also significantly increased in patients with psoriatic arthritis. We also found that the association of CYP1A1 4887A with psoriatic arthritis was independent of 4889G but a synergistic effect was present between CYP1A1 4887A and 4889G. The CYP1A1 4889A/G and 4887C/A polymorphisms were not associated with the manifestations and severity of psoriatic arthritis. CONCLUSION: CYP1A1 4887A and 4889G may be precipitating factors for susceptibility to psoriatic arthritis in Taiwan. An additive effect was found between CYP1A1 4887A and 4889G.

Arthritis, Psoriatic↗
PubMed2004

Psoriatic patients with arthropathy show significant expression of free HLA class I heavy chains on circulating monocytes: a potential role in the pathogenesis of psoriatic arthropathy.

BACKGROUND: Surface free heavy chains on monocytes were recently implicated in playing a role in the pathogenesis of several forms of arthritis. OBJECTIVES: To determine the expression of surface free heavy chains (recognized by monoclonal antibody HC10) on peripheral blood mononuclear cells of psoriatic patients with or without arthropathy. METHODS: Twenty-eight psoriatic patients from the dermatology outpatient clinic were included in this study. Blood samples were collected during outpatient visits and clinical characteristics of the patients were documented. Quantitative analyses of circulating mononuclear cells were performed using flow cytometry. RESULTS: Circulating monocytes showed higher expression of HC10 compared with circulating lymphocytes (P < 0.05). Psoriatic patients with arthropathy showed elevated expression of HC10 on peripheral blood monocytes compared with those without arthropathy (P < 0.05). Among the arthropathic group, those without the human leucocyte antigen (HLA)-B27 allele showed even higher expression of HC10 on circulating monocytes compared with those possessing HLA-B27 (P < 0.05). The polyarthropathic subgroup showed the highest HC10 expression, but the level of expression was not high enough to be of statistical significance compared with other arthropathic subgroups. No correlation was found between psoriatic skin involvement and the expression of HC10 on circulating monocytes. CONCLUSIONS: The presence of free heavy chains on circulating monocytes is closely associated with psoriatic arthropathy, while the expression of free heavy chains on circulating monocytes has no significant influence on psoriatic skin lesions.

Adolescent↗
PubMed2002

A 588-gene microarray analysis of the peripheral blood mononuclear cells of spondyloarthropathy patients.

OBJECTIVES: To identify genes which are more highly expressed in the peripheral blood mononuclear cells (PBMC) of patients with spondyloarthropathy (SpA), rheumatoid arthritis (RA) and psoriatic arthritis (PsA), in comparison to normal subjects. METHODS: A 588-gene microarray was used as a screening tool to select a panel of such genes from PBMC of these subjects and of normal subjects. Results were then validated by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The following genes were more highly expressed in arthritis patients than in normal subjects: macrophage differentiation marker MNDA (myeloid nuclear differentiation antigen), MRP8 and MRP14 (migratory inhibitory factor-related proteins); signalling molecules JAK3 (janus kinase 3) and MAP kinase p38 (mitogen-activated protein kinase); receptors TNFR2/p75, C-C-chemokine receptor type 1 (CCR1), C-X-C-chemokine receptor type 4 (CXCR4) and integrin beta1; and the cytokines/chemokines interleukin (IL) 1beta and IL-8. Expression of CXCR4 was unexpectedly high among all arthritis subjects. Using RT-PCR, ELISA and immunohistology, expression of stromal cell-derived factor 1 (SDF-1) was demonstrated in arthritis joints. CONCLUSIONS: The CXCR4/SDF-1 is a potential pro-inflammatory axis for RA, PsA and SpA.

Adolescent↗
PubMed2001

Surface characteristics of Bacillus cereus and its adhesion to stainless steel.

The ability of a Bacillus cereus strain, isolated from spoiled milk, to adhere to the surface of stainless steel chips was evaluated during its growth in diluted tryptic soy broth (DTSB). The number of cells that adhered to the surface increased markedly as the culture reached the end of the log phase and entered stationary phase, and continued to increase with further incubation. The surface properties of cells from the log, stationary, and late stationary phases were measured by hydrophobic interaction chromatography (HIC) and electrostatic interaction chromatography (ESIC). It was found that surface hydrophobicity of B. cereus vegetative cells from the late stationary phase was the highest followed by those from the stationary phase and the log phase cultures. While the vegetative cells prepared from stationary phase and log phase cultures, respectively, had the highest and the lowest surface charges. Adhesion of B. cereus vegetative cells to stainless steel was positively correlated with the cell surface hydrophobicity (R = 0.979). Surface hydrophobicity and surface positive charge noted on the spores harvested from diluted tryptic soy agar (DTSA) and Mn2+-tryptone glucose extract agar were higher than those harvested from the sucrose or lactose-added DTSA. A wide variation in the surface charge values was noted on the surface of various spores prepared from cultures grown on the four different media tested, while their ability to adhere to stainless steel chips in phosphate buffered saline (PBS) showed no significant difference (p > 0.05). Similarly, the number of spores or vegetative cells adhering to stainless steel suspended in PBS, milk or diluted milk (1000 x) did not differ significantly (p > 0.05).

Agar↗
PubMed2001

Distinct regulation of genes by bFGF and VEGF-A in endothelial cells.

A finely tuned balance of angiogenic inhibitors and inducers controls the activity of angiogenesis characterized by proliferation, migration and differentiation of endothelial cells. Among many angiogenic factors, basic fibroblast growth factor (bFGF) was first identified to be angiogenic whereas vascular endothelial growth factor A (VEGF-A) is an endothelial cell specific mitogen. In addition to being a specific mitogen, VEGF-A is also known as a vascular permeability factor. The majority of growth factors transduce their mitogenic signals from cell surface to nucleus where gene expression occurs. Whether these ligands utilize a distinct or a common molecular pathway to exert their biological effects on human endothelial cells remains elusive. We thus studied the expression profile of 884 human genes under the influence of either bFGF or VEGF-A alone in the context of human endothelial cells. A total of ninety-four genes were differentially regulated by more than two folds. The expression patterns of 32 genes are similar between the treatment of either factor alone whereas those of the remaining 62 genes are only regulated by one but not the other factor. Their function in the control of angiogenesis will be discussed and apoptotic signaling in the regulation of angiogenesis is also implicated.

Blotting, Northern↗
PubMed2001

Chemokine-dependent neutrophil recruitment in a murine model of Legionella pneumonia: potential role of neutrophils as immunoregulatory cells.

The roles of CXC chemokine-mediated host responses were examined with an A/J mouse model of Legionella pneumophila pneumonia. After intratracheal inoculation of 10(6) CFU of L. pneumophila, the bacterial numbers in the lungs increased 10-fold by day 2; this increase was accompanied by the massive accumulation of neutrophils. Reverse transcription-PCR data demonstrated the up-regulation of CXC chemokines, such as keratinocyte-derived chemokine, macrophage inflammatory protein 2 (MIP-2), and lipopolysaccharide-induced CXC chemokine (LIX). Consistent with these data, increased levels of KC, MIP-2, and LIX proteins were observed in the lungs and peaked at days 1, 2, and 2, respectively. Although the administration of anti-KC or anti-MIP-2 antibody resulted in an approximately 20% decrease in neutrophil recruitment on day 2, no increase in mortality was observed. In contrast, the blockade of CXC chemokine receptor 2 (CXCR2), a receptor for CXC chemokines, including KC and MIP-2, strikingly enhanced mortality; this effect coincided with a 67% decrease in neutrophil recruitment. Interestingly, anti-CXCR2 antibody did not affect bacterial burden by day 2, even in the presence of a lethal challenge of bacteria. Moreover, a significant decrease in interleukin-12 (IL-12) levels, in contrast to the increases in KC, MIP-2, and LIX levels, was demonstrated for CXCR2-blocked mice. These data indicated that CXCR2-mediated neutrophil accumulation may play a crucial role in host defense against L. pneumophila pneumonia in mice. The increase in lethality without a change in early bacterial clearance suggested that neutrophils may exert their protective effect not through direct killing but through more immunomodulatory actions in L. pneumophila pneumonia. We speculate that a decrease in the levels of the protective cytokine IL-12 may explain, at least in part, the high mortality in the setting of reduced neutrophil recruitment.

Animals↗
PubMed2001

Bloodletting acupuncture of the engorged vein around Bl-40 (Wei-Chung) for acute lumbar sprain.

Bloodletting acupuncture is one of the most classic methods of acupuncture therapy, and is still popularly used to treat acute lumbar sprain in the oriental world. However, most physicians in the western world are not familiar with bloodletting acupuncture, though they may know ordinary acupuncture well. Furthermore based on the literature reviewed, there have been few studies which have investigated the effect of bloodletting acupuncture upon acute lumbar sprain. In this study, we tried to determine if bloodletting acupuncture is effective for acute lumbar sprain. In total, twelve patients were enrolled for analysis. Five patients were treated with ordinary acupuncture upon the contralateral SI-3 (Hou-Hsi) point alone. Seven patients were first treated with bloodletting acupuncture to the engorged vein around the ipisilateral Bl-40 (Wei-Chung), and then followed by ordinary acupuncture upon the contralateral SI-3. It was demonstrated that bloodletting acupuncture to the engorged vein around the ipisilateral Bl-40 followed by ordinary acupuncture upon the contralateral SI-3 had more pain relief than ordinary acupuncture upon the contralateral SI-3 alone (83 +/- 23% vs. 44 +/- 28%) (P < 0.01). And bloodletting acupuncture to the engorged vein around the ipisilateral Bl-40 decreased pain by 56 +/- 23%, similar to that of ordinary acupuncture upon the contralateral SI-3 alone (44 +/- 28%). These findings suggest that bloodletting acupuncture to the engorged vein around the ipisilateral Bl-40 (Wei-Chung) has a substantial contribution for treatment of acute lumbar sprain.

Acupuncture↗