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Biomedical subjects

J H Yen

Publications and source records attributed to J H Yen.

At least 19 recordsLinked to original sources
PubMed2005

On-site mercury-contaminated soils remediation by using thermal desorption technology.

In this study, the thermal desorption process was used to treat a mercury-contaminated soils in Taipei. A series of bench or pilot plant experiments were also performed the optimized operation condition. The results showed that the concentrations of residual mercury in all treated soils were below 2 mg/kg, some even lower than 0.05 mg/kg. The supernatant and exhaust gas stream of the condensed desorbed mercury vapor in the remediation site were also met with the effluent standard. The total fee was estimated to be US 3,557,000 dollars, when treating contaminated soil leading to a unit treatment cost of US 834 dollars/m3 of soil.

Absorption↗
PubMed2005

Novel electrodeposition behavior of Ni on porous anodic alumina templates without a conductive interlayer.

During template-assisted electrodeposition, single-crystalline metallic nanowires could be obtained only when the overpotential is low. However, an unusual electrodeposition behavior on the PAA/Si substrate without a conductive interlayer between the template and Si is described in the present study. Through the electrical breakdown of the template, Ni nanodots, nanowires and nanotubes could be obtained by only changing the electrodeposition voltage on the same substrate. The mechanisms leading to the formation of various nanostructures are described in detail and compared with those for the conventional template-assisted electrodeposition process. The electrodeposition first occurred on the pore wall instead of from the underlying substrate, leading to the formation of some Ni nanotubes at a more negative voltage. Besides, single-crystalline Ni nanowires could also be formed even when the electrodeposition voltage was as negative as -40 V, indicating that the formation of single-crystalline metallic nanowires under a large overpotential is possible.

Journal Article↗
PubMed2005

Antibody to severe acute respiratory syndrome (SARS)-associated coronavirus spike protein domain 2 cross-reacts with lung epithelial cells and causes cytotoxicity.

Both viral effect and immune-mediated mechanism are involved in the pathogenesis of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) infection. In this study, we showed that in SARS patient sera there were autoantibodies (autoAbs) that reacted with A549 cells, the type-2 pneumocytes, and that these autoAbs were mainly IgG. The autoAbs were detectable 20 days after fever onset. Tests of non-SARS-pneumonia patients did not show the same autoAb production as in SARS patients. After sera IgG bound to A549 cells, cytotoxicity was induced. Cell cytotoxicity and the anti-epithelial cell IgG level were positively correlated. Preabsorption and binding assays indicated the existence of cross-reactive epitopes on SARS-CoV spike protein domain 2 (S2). Furthermore, treatment of A549 cells with anti-S2 Abs and IFN-gamma resulted in an increase in the adherence of human peripheral blood mononuclear cells to these epithelial cells. Taken together, we have demonstrated that the anti-S2 Abs in SARS patient sera cause cytotoxic injury as well as enhance immune cell adhesion to epithelial cells. The onset of autoimmune responses in SARS-CoV infection may be implicated in SARS pathogenesis.

Autoantibodies↗
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↗
PubMed2001

Major histocompatibility complex class I-recognizing receptors are disease risk genes in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a heterogeneous syndrome of which a subset of patients develops vascular inflammation. The genetic determinants that confer risk for rheumatoid vasculitis are not known, but patients with vascular complications are known to have an expansion of CD4(+)CD28(null) T cells, a cell population potentially involved in endothelial damage. CD4(+)CD28(null) T cell clones isolated from RA patients with vasculitis were found to express killer cell immunoglobulin-like receptors (KIRs) with the stimulatory KIR2DS2 often present in the absence of opposing inhibitory receptors with related specificities. To test the hypothesis that the KIR2DS2 gene is involved in the development of vasculitis, association studies were performed. The KIR2DS2 gene was significantly enriched among patients with rheumatoid vasculitis compared with normal individuals (odds ratio 5.56, P = 0.001) and patients with RA but no vasculitis (odds ratio 7.96, P = 0.001). Also, the distribution of human histocompatibility leukocyte antigen (HLA)-C, the putative ligand for KIRs, was significantly different in patients with rheumatoid vasculitis in comparison with the control populations. These data suggest that HLA class I-recognizing receptors and HLA class I genes are genetic risk determinants that modulate the pattern of RA expression. Specifically, KIR2DS2 in conjunction with the appropriate HLA-C ligand may have a role in vascular damage by regulating CD4(+)CD28(null) T cells.

Antigens, CD↗
PubMed2001

Environmental dissipation of fungicide triphenyltin acetate and its potential as a groundwater contaminant.

The effects of various factors on fungicide triphenyltin acetate dissipation in selected soil types were studied; temperature is clearly the most important factor of these. Residues of this fungicide in Fangtzupo clay loam and Lanyang loam incubated at 30 degrees C for 32 days (water content 100, 70, or 40% of field capacity) were 25% of the original amounts. In soil samples incubated at 10, 30, or 40 degrees C with 100% field capacity water content, residues were 80, 26, and 5.5% for Fangtzupo soil, respectively, and 83, 26, and 7.0% for Lanyang soil, respectively. No significant difference in dissipation rate was found between sterilized and unsterilized soil, suggesting that microbial degradation is not an important factor in this process. Rapid degradation rates were observed-half-lives of 8.3 to 19.4 days in Fangtzupo clay loam and 8.0 to 16.3 days in Lanyang loam at temperatures ranging from 30 to 40 degrees C (soil water content of 100, 70, and 40% of field capacity). Significant increases in half-life (approximately 150 days) occurred at lower temperatures (10 degrees C) in both soil types. The potential of triphenyltin acetate to contaminate groundwater was tested using the behavior assessment and groundwater pollution-potential models. Results indicate that the leaching rate of the fungicide is very slow (1.0 cm day(-1)) under normal conditions.

Biodegradation, Environmental↗
PubMed2001

Preparation and value assignment of Standard Reference Material 968c Fat-Soluble Vitamins, Carotenoids, and Cholesterol in Human Serum.

Standard Reference Material 968c Fat-Soluble Vitamins, Carotenoids, and Cholesterol in Human Serum provides certified values for retinal, delta-, gamma-, and alpha-tocopherol, trans- and total beta-carotene, and cholesterol in human serum. Values are also reported for 16 additional compounds including lutein, zeaxanthin, alpha- and beta-cryptoxanthin, lycopene, alpha-carotene, retinyl palmitate, and 25-hydroxyvitamin D. The certified values for the fat-soluble vitamins and carotenoids in SRM 968c were based on the agreement of results from the means of at least two liquid chromatographic methods used at the National Institute of Standards and Technology (NIST) and from the medians from an interlaboratory comparison study among institutions that participate in the NIST Micronutrients Measurement Quality Assurance Program. The assigned values for cholesterol in the SRM are the means of results obtained using the NIST definitive method, gas chromatography-isotope dilution mass spectrometry.

Calibration↗
PubMed2001

Biodegradation of phenanthrene in river sediment.

The aerobic biodegradation potential of phenanthrene (a polycyclic aromatic hydrocarbon [PAH]) in river sediment was investigated in the laboratory. Biodegradation rate constants (k1) and half-lives (t1/2) for phenanthrene (5 microg/g) in sediment samples collected at five sites along the Keelung River in densely populated northern Taiwan ranged from 0.12 to 1.13 l/day and 0.61 to 5.78 day, respectively. Higher biodegradation rate constants were noted in the absence of sediment. Two of the sediment samples were capable of biodegrading phenanthrene at initial concentrations 5-100 microg/g; lower biodegradation rates occurred at higher concentrations. Optimal biodegradation conditions were determined as 30 degreesC and pH 7.0. Biodegradation was not significantly influenced by the addition of such carbon sources as acetate, pyruvate, and yeast extract, but was significantly influenced by the addition of ammonium, sulfate, and phosphate. Results show that anthracene, fluorene, and pyrene biodegradation was enhanced by the presence of phenanthrene, but that phenanthrene treatment did not induce benzo[a]pyrene biodegradation during a 12-day incubation period.

Adsorption↗
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↗
PubMed2001

HLA-DQA1 genotyping in patients with rheumatoid arthritis in Taiwan.

To investigate the role of HLA-DQA1 genotypes and their interaction with HLA-DRB1 in the pathogenesis of rheumatoid arthritis (RA) in Taiwan, HLA-DQA1 was determined in 71 patients with RA and 108 healthy controls by SSP-PCR method. HLA-DRB1 and HLA-DQA1 were simultaneously detected in 55 RA patients and 101 healthy controls. PCR/SSOP method was used to determine the HLA-DRB1 genotypes, and the subtypes of HLA-DR4 were determined by cloning and sequencing. The phenotypic frequency of HLA-DQA1*0301 was significantly lower in RA than in controls, and, in contrast, the HLA-DQA1*0302 and DQA1*0303 were significantly higher in RA than in controls. The associations of DQA1*0301, *0302, and *0303 with RA were independent of DR4 and DRB1*0405. Moreover, the interactions between HLA-DR4 and HLA-DQA1*0302 or DQA1*0303 could enhance the development of RA. We also found that the prevalence of bone erosion and seropositivity of rheumatoid factor (RF) were significantly higher in HLA-DQA1*0303 positive RA patients than in healthy controls. HLA-DQA1*0302 and DQA1*0303 are the risk factors for susceptibility to RA, while HLA-DQA1*0301 is a protective factor. A synergistic effect for the susceptibility to RA can be found between HLA-DR4 and HLA-DQA1*0302 or DQA1*0303. We also found that the HLA-DQA1*0303 was related to bone erosion and seropositivity of RF in RA patients.

Alleles↗
PubMed2001

Familial Mediterranean fever in a Taiwanese patient.

Familial Mediterranean fever is a rare disease characterized by cyclic attacks of fever, serositis and strong family background. Here we report a 22-year-old man who suffered from recurrent fever accompanied by chest and abdominal pain for more than 10 years. The attack frequency was about once per 2-3 weeks. Although he consulted many clinics and even received appendectomy at the age of 15, no definite diagnosis was given. During the admission, many laboratory examinations failed to show any abnormality except mild leukocytosis and elevated C-reaction protein. Image studies including chest X ray and abdominal CT scan showed negative result but, interestingly, Gallium-67 scan showed a hot spot in right lower chest and right lower abdomen. After prophylaxis with colchicine 1.0 mg per day, he has enjoyed more than 2 years without the above symptoms.

Adult↗
PubMed2001

Tumor necrosis factor promoter polymorphisms in patients with rheumatoid arthritis in Taiwan.

OBJECTIVE: To investigate the association of tumor necrosis factor (TNF) promoter polymorphisms with rheumatoid arthritis (RA) in Taiwan. METHODS: TNF promoter polymorphisms at positions -238, -244, -308, -376, -857, and -863 were determined in 97 patients with RA and 97 healthy controls using the PCR-RFLP method. RESULTS: The phenotypic frequency of TNF-308A was significantly lower in patients with RA than in healthy controls. This finding can only be found in HLA-DR4 negative patients, not in DR4 positive RA patients and controls. The TNF promoter polymorphisms at positions -238, -244, -308, -376, -857, and -863 were not related to the clinical manifestations of RA patients. CONCLUSION: TNF-308A itself or a neighboring gene may be a protective factor for the development of RA in the HLA-DR4 negative population in Taiwan. TNF promoter polymorphisms were not associated with the clinical manifestations of patients with RA in Taiwan.

Arthritis, Rheumatoid↗
PubMed2001

Carbon dioxide flux density in cultivated rice paddy field.

The carbon dioxide flux density in a subtropical cultivated rice paddy field were determined over four crop seasons (two consecutive years) at five stages of rice plant development, transplanting, active tillering, booting, flowering and ripening, and an idle period between crops. During 24 h sampling periods at those stages, the CO2 flux densities were measured and found to be -2,000 to 55,000 mg CO2/m2/day in the first year and 600 to 29,000 mg CO2/m2/day in the second year in acrylic chambers covering rice plants. The CO2 flux densities in glass domes without plants but with soil were -700 to 6,000 mg CO2/m2/day in the first year and 147 to 4,500 mg CO2/m2/day in the second year. The data for the CO2 flux density over an entire year are extrapolated. Although our non-controlled environment experiments have inherent drawbacks, the collected data indicate that continuous rice cultivation has a tendency to result in increased CO2 emissions.

Carbon Dioxide↗
PubMed2001

Systemic lupus erythematosus complicated by recurrent spontaneous pneumothorax--a case report.

Despite frequent pleuro-pulmonary involvement, spontaneous pneumothorax is rare in patients with systemic lupus erythematosus (SLE). Here, we report a 17-year-old female patient with SLE, complicated by multiple organs involvement. She initially presented with interstitial pneumonitis and pulmonary hemorrhage, followed by spontaneous pneumothorax and CNS involvement. The patient was treated with immunosuppressive agents, including steroid and cyclophosphamide pulse therapies. Spontaneous pneumothorax happened to her once again at a different location during treatment. After aggressive therapy, the disease activity of SLE gradually diminished, and pneumothorax had not recurred during the further follow-up. Therefore, the pneumothorax may occur in SLE patients with high disease activity.

Adolescent↗
PubMed2000

Killer cell activating receptors function as costimulatory molecules on CD4+CD28null T cells clonally expanded in rheumatoid arthritis.

Expansion of CD4+CD28null T cells is a characteristic finding in patients with rheumatoid arthritis. Despite lacking CD28 molecules, these unusual CD4 T cells undergo clonal proliferation and form large and long-lived clonal populations. They produce high levels of IFN-gamma, exhibit autoreactivity, and have cytolytic function. The mechanisms facilitating the expansion and longevity of CD4+CD28null T cell clones in vivo are unknown. Here, we report that CD4+CD28null, but not CD4+CD28+, T cells express MHC class I-recognizing receptors normally found on NK cells. CD4+CD28null T cells preferentially expressed killer cell activating receptors (KAR), often in the absence of killer cell inhibitory receptors. Cross-linking of KAR molecules enhanced the proliferative response to TCR-mediated stimulation, but not the cytolytic function of CD4+CD28null T cells, suggesting different signaling pathways in CD4 T cells and NK cells. Triggering of KAR signaling led to the phosphorylation of several cellular targets, although the pattern of phosphorylation differed from that induced by the TCR. Aberrant expression of KAR molecules in the absence of inhibitory receptors and in the appropriate HLA setting may lead to the clonal outgrowth of autoreactive CD4+CD28null T cells commonly seen in rheumatoid arthritis.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Potential of the insecticides acephate and methamidophos to contaminate groundwater.

The possible contamination of groundwater by the insecticides acephate and methamidophos was assessed using the behavior assessment model (BAM) and the groundwater pollution-potential model (GWP). The dissipation coefficients of the two insecticides in two soils (Annei silt loam and Pingchen silt clay loam) at different moisture contents (50 and 100% field capacity) and soil temperatures (20 and 30 degrees C) were studied by determining the degradation and adsorption of each insecticide in the soil. The movement of acephate and methamidophos was studied by leaching each insecticide in a soil column in the laboratory. The absorption coefficient of methamidophos was much higher than that of acephate in both types of soil. In the leaching test, methamidophos more easily leached out from the Pingchen soil column than from the Annei soil column. Methamidophos was rapidly degraded, with a half-life of 1.11 to 1.61 days in the Annei soil and 7.50 to 13.20 days in the Pingchen soil at different temperatures and soil water contents. Acephate was found to have a longer half-life than methamidophos in soil; however, the mobility of methamidophos in both soils was slower than that of acephate. The mobility of acephate in soil is somewhat faster than that of methamidophos, and thus acephate may lead to the contamination of groundwater much more easily than methamidophos under normal conditions.

Adsorption↗