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Zheng YL, Lu XL, Lin J, Chen HM, Yan XJ, Wang F, Xu WF. Direct effects of fascaplysin on human umbilical vein endothelial cells attributing the anti-angiogenesis activity. Biomed Pharmacother 2009; 64:527-33. [PMID: 19932581 DOI: 10.1016/j.biopha.2009.04.046] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 04/15/2009] [Indexed: 10/20/2022] Open
Abstract
Novel anti-angiogenesis activity of fascaplysin via VEGF blockage was recently revealed by our previous study in addition to the reported cyclin-dependent kinase 4 (CDK4) selective inhibition. To uncover more details of this pharmacologically prospective property, this study further investigated whether fascaplysin had direct anti-proliferation effects on human umbilical vein endothelial cells (HUVEC), which might be contributing to anti-angiogenesis. The results showed that G1 cell cycle arrest was induced by 2.6 μM fascaplysin in a time-dependent manner, and exhibited more sensitive than hepatocarcinoma cells BeL-7402 and Hela cells. Approximately 56.09 ± 2.63% of the cells were arrested at the G1 phase after 24h, and 64.94 ± 2.07% after 36 h, comparing to the 22.82 ± 1.2% in methanol treated cells. Apoptosis of HUVEC cells was induced by 1.3 μM fascaplysin and indicated by the sub-G1, Hoechst staining, terminal deoxynucleotidyl transferase dUTP-mediated nicked end labeling (TUNEL) assay, and annexin-V and propidium (PI) label. This apoptosis response was further confirmed by the detection of active caspase-3 and by western blotting using antibodies against Bax, Bcl-2, procaspase-8, and Bid, indicating that apoptosis in HUVEC cells may involve a mitochondria pathway, by the demonstration of an increase in the Bax/Bcl-2 ratio. Together, our results suggest that the anti-angiogenesis activity of fascaplysin is through the direct effects of cell cycle arrest and apoptosis on HUVEC.
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Chang YC, Lin JW, Wang LC, Chen HM, Hwang JJ, Chuang LM. Association of intraocular pressure with the metabolic syndrome and novel cardiometabolic risk factors. Eye (Lond) 2009; 24:1037-43. [PMID: 19816514 DOI: 10.1038/eye.2009.247] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Cheng SJ, Huang CF, Chen YC, Lee JJ, Chang HH, Chen HM, Chiang ML, Kuo MY, Kok SH, Tseng CY. Ultrastructural changes of posterior lingual glands after hypoglossal denervation in hamsters. J Anat 2009; 214:163-70. [PMID: 19166479 DOI: 10.1111/j.1469-7580.2008.01019.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Posterior lingual glands consist of two sets of minor salivary glands that serve important functions in oral physiology. To investigate the hypothesis that the hypoglossal nerve provides sympathetic innervation to the posterior lingual glands, we examined ultrastructural changes in the glands following hypoglossal denervation. In the posterior deep lingual glands (of von Ebner), the serous acinar cells showed a decrease in the number of secretory granules and an increase in lipofuscin accumulation. The ratios of cells containing lipofuscin granules were 11.39, 36.49 and 50.46%, respectively, of the control, 3- and 7-day post-axotomy glands (P < 0.001). Intraepithelial phagocytotic activity was increased. The mucous acinar cells in the posterior superficial lingual glands (of Weber) also showed degenerative changes after hypoglossal denervation. One week after nerve transection, marked cytoplasmic vacuolation and fragmentation of organelles were frequently observed. Degenerative changes were also found in unmyelinated axons associated with the glands. We provide the first evidence of the structural and functional connections between the sympathetic component of the hypoglossal nerve and posterior lingual glands.
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Hung CS, Lin JW, Hsu CN, Chen HM, Tsai RY, Chien YF, Hwang JJ. Using brachial-ankle pulse wave velocity to associate arterial stiffness with cardiovascular risks. Nutr Metab Cardiovasc Dis 2009; 19:241-246. [PMID: 18815016 DOI: 10.1016/j.numecd.2008.07.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2008] [Revised: 07/12/2008] [Accepted: 07/14/2008] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND AIMS This study aimed to elucidate the relationship between brachial-ankle pulse wave velocity (baPWV) and conventional cardiovascular risk factors. METHODS AND RESULTS A total of 192 subjects with low to intermediate risk was enrolled in a cardiovascular evaluation program. A multiple regression model was built to find significant cardiovascular biomarkers for predicting baPWV. A logistic regression model was developed to associate baPWV and other biomarkers with the risk of cardiac diastolic dysfunction. A total of 123 men (mean age: 52.6+/-12.0) and 69 women (mean age: 51.7+/-10.4) was included. Age, blood pressure, C-reactive protein, serum homocysteine, heart rate, and blood urea nitrogen were positively predictive of increased pulse wave velocity. In turn, baPWV increased the risk (odds ratio: 1.257 for each m/s, 95% CI: 1.105 approximately 1.430, p<0.001) and high-density lipoprotein decreased the risk for cardiac diastolic dysfunction (0.962 for each mg/dl, 95% CI: 0.925 approximately 1.000, p=0.05). The correlation between baPWV and Framingham 10-year risk was moderate (men: r=0.306, p=0.002; women r=0.548, p<0.001). CONCLUSION The results suggest that baPWV is a composite risk factor for early atherosclerotic change and a predictor for the development of diastolic dysfunction and long-term cardiovascular risk.
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Chen HM, Wu JJ, Tsai PF, Wann JY, Yan JJ. Evaluation of the capability of the VITEK 2 system to detect extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates, in particular with the coproduction of AmpC enzymes. Eur J Clin Microbiol Infect Dis 2009; 28:871-4. [PMID: 19214606 DOI: 10.1007/s10096-009-0713-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Accepted: 01/25/2009] [Indexed: 10/21/2022]
Abstract
A total of 317 Klebsiella pneumoniae and 291 Escherichia coli nonduplicate isolates were tested by the VITEK 2 system to evaluate its capability to detect extended-spectrum beta-lactamases (ESBLs) among putative ESBL-producing isolates, in particular those with the coproduction of AmpC enzymes. beta-lactamases produced by the test isolates had been characterised. The sensitivity and specificity for ESBLs were 98.9% and 98.5%, respectively. Ninety of the isolates were AmpC (CMY-2, CMY-8 or DHA-1) and ESBL (SHV and/or CTX-M) coproducers, and 74 isolates (82.2%) of them were flagged as ESBL producers. Our study indicates that the VITEK 2 system is an acceptable tool for ESBL detection among K. pneumoniae and E. coli isolates for laboratories where both imported AmpC and ESBLs are prevalent.
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Kuriya B, Cheng CK, Chen HM, Bykerk VP. Validation of a prediction rule for development of rheumatoid arthritis in patients with early undifferentiated arthritis. Ann Rheum Dis 2008; 68:1482-5. [DOI: 10.1136/ard.2008.092676] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Objective:To validate a model which predicts progression from undifferentiated arthritis (UA) to RA, in a Canadian UA cohort.Methods:The prediction rule, comprising variables which are scored from 0 to 13, with higher scores reflecting an increased risk of RA, was applied to baseline characteristics of all patients with UA. Progression to RA was determined at 6 months.Results:105 patients were identified. By 6 months, 80 (76%) had developed RA while 25 (24%) had developed another diagnosis. Number of tender and swollen joints, rheumatoid factor positivity, anti-cyclic citrullinated peptide positivity, poor functional status and high disease activity were associated with development of RA (p<0.01). Median prediction score was 8.0 for progressors, 5.0 for non-progressors. With these cut-off points, 18 (72%) patients with scores ⩽5 did not develop RA, while 35 (97%) with scores ⩾8 did develop RA.Conclusions:High scores in our cohort predicted those who progressed to RA by 6 months. Baseline scores ⩾8 corresponded with higher rates of progression.
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Ullman E, Fan Y, Stawowczyk M, Chen HM, Yue Z, Zong WX. Autophagy promotes necrosis in apoptosis-deficient cells in response to ER stress. Cell Death Differ 2008; 15:422-5. [PMID: 17917679 PMCID: PMC3140950 DOI: 10.1038/sj.cdd.4402234] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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Chen HM, Chiu CC, Wu JR, Chen YF. A simple model for variant congenital cardiac anomalies. Thorac Cardiovasc Surg 2007; 55:433-7. [PMID: 17902065 DOI: 10.1055/s-2007-965303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND Traditionally, echocardiography, computed tomography and angiocardiography are used to detect the anatomy of congenital cardiac defects. Either pediatric cardiologists or cardiac surgeons mentally reconstruct these images into a vague imaginary three-dimensional heart, but such an image usually includes unnecessary surrounding structures which may mask the defects to be detected. METHOD We use a perspective view model to draw a more stereoscopic picture of complex hearts instead of the simple two-dimensional sketch. With this model we have the ability to display cardiovascular anatomy in a three-dimensional structure to increase the understanding and appreciation of the complex spatial relationships in the majority of congenital hearts. RESULTS Through these drawn images the physiology and structural defects of hearts may be understood more easily and explained more clearly in comparison to two-dimensional representations. CONCLUSION The simple perspective drawing is not used to replace the three-dimensional examinations, but it is helpful in reconstructing a model of the heart based on the information we obtain through serial examinations, and such a model may be used to teach medical students, as well as to explain defects to patients' families.
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Mahanivong C, Chen HM, Yee SW, Pan ZK, Dong Z, Huang S. Protein kinase C alpha-CARMA3 signaling axis links Ras to NF-kappa B for lysophosphatidic acid-induced urokinase plasminogen activator expression in ovarian cancer cells. Oncogene 2007; 27:1273-80. [PMID: 17724468 PMCID: PMC4513671 DOI: 10.1038/sj.onc.1210746] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We reported previously that a signaling pathway consisting of G(i)-Ras-NF-kappaB mediates lysophosphatidic acid (LPA)-induced urokinase plasminogen activator (uPA) upregulation in ovarian cancer cells. However, it is not clear what signaling components link Ras to nuclear factor (NF)-kappaB for this LPA-induced event. In the present study, we found that treatment of protein kinase C (PKC) inhibitors including conventional PKC (cPKC) inhibitor Gö6976 abolished LPA-induced uPA upregulation in ovarian cancer cell lines tested, indicating the importance of cPKC activity in this LPA-induced event. Indeed, LPA stimulation led to the activation of PKCalpha and Ras-PKCalpha interaction. Although constitutively active mutants of PKCalpha (a cPKC), PKCtheta (a novel PKC (nPKC)) and PKCzeta (an atypical PKC (aPKC)) were all able to activate NF-kappaB and upregulate uPA expression, only dominant-negative PKCalpha mutant attenuated LPA-induced NF-kappaB activation and uPA upregulation. These results suggest that PKCalpha, rather than PKC isoforms in other PKC classes, participates in LPA-induced NF-kappaB activation and uPA upregulation in ovarian cancer cells. To determine the signaling components downstream of PKCalpha mediating LPA-induced uPA upregulation, we showed that forced expression of dominant-negative CARMA3 or silencing CARMA3, Bcl10 and MALT1 with specific siRNAs diminished these LPA-induced events. Furthermore, we demonstrated that PKCalpha/CARMA3 signaling axis is important in LPA-induced ovarian cancer cell in vitro invasion.
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Chang CL, You C, Chen HM, Chiang CP, Chen CT, Wang CY. Autofluorescence lifetime measurement on oral carcinogenesis. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2004:2349-51. [PMID: 17270741 DOI: 10.1109/iembs.2004.1403681] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Normal and cancerous tissues have distinct autofluorescence lifetime because of their biophysical and biochemical differences. Protoporphyrin IX (PplX) is a useful fluorophore, which generally accumulates more in cancerous cells than in normal cells due to heme synthesis pathway, is often employed in photodynamic detection and therapy. Under 410nm excitation, the main emission peak of PplX is at 630nm. Autofluorescence lifetime at 630nm emission would be elongated if PplX gathered more in cells. In this study, we tried to find if there exist significant differences of autofluorescence lifetime at 630nm (under 410nm excitation) between normal and cancerous tissues for in vivo measurement. The result shows that normal tissues in general have shorter lifetime (about 2.8 approximately 3.5 ns) than that of abnormal tissues. The measured data suggest that lifetime would get longer in accordance with the degree of carcinogenesis. For cancer tissues, the average autofluorescence lifetime was extended to be about 10ns. Furthermore, the efficiency of treatment could also be defined refer to the time-series of lifetime decline.
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Chang JM, Kuo MC, Chen HM, Lee CH, Lai YH, Chen HC, Hwang SJ. Endothelin-1 regulates parathyroid hormone expression of human parathyroid cells. Clin Nephrol 2006; 66:25-31. [PMID: 16878432 DOI: 10.5414/cnp66025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE Parathyroid cells synthesize and release endothelin-1 (ET-1). ET-1 displays an in vitro inhibitory effect on basal parathyroid hormone (PTH) secretion and also counteracts PTH hypersecretion stimulated by low calcium. Such effects are further demonstrated in vivo, independent of the changes in calcitonin. We propose that ET-1 may regulate the pathogenesis of uremic hyperparathyroidism. However, this was not directly demonstrated in human parathyroid glands. DESIGN Hyperplastic parathyroid glands are obtained from the surgical operation for uremic hyperparathyroidism. Cells are isolated by enzyme digestion and treated with ET-1, and are assessed for PTH mRNA expression. PTH in the plasma and the medium is measured by a newly developed method to detect the whole PTH (1-84). PATIENTS Uremic patients with severe secondary hyperparathyroidism and ultrasonography-proved hypertrophy of parathyroid glands received elective surgical approaches under general anesthesia. The resected glands were immediately taken to the laboratory for fresh isolation. MEASUREMENTS Following ET-1 treatment, PTH mRNA expression is evaluated by RT-PCR method. ET-1 is detected with radioimmunoassay kit and PTH is measured by a new commercially available Duo PTH kit. RESULTS ET-1 exhibited a dose-dependent inhibitory effect (from 10(-12) - 10(-7) M) on PTH mRNA expression of parathyroid cells, either in the basal or in the low-calcium-stimulated states. Release of PTH into the medium is also gradually inhibited by the increase in ET-1 concentrations. CONCLUSIONS Our results demonstrate that ET-1 attenuates PTH mRNA expression in freshly isolated human parathyroid cells, and PTH release is also decreased. This result is consistent with our previously reported in vitro and in vivo experiments.
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Liu HL, Huang CM, Lim SN, Kuan WC, Chen HM, Wu T, Hsu YY. SU-FF-I-68: False Positive Analysis of Functional MRI During Simulated Deep Brain Stimulation. Med Phys 2006. [DOI: 10.1118/1.2240748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Patton KT, Chen HM, Joseph L, Yang XJ. Decreased annexin I expression in prostatic adenocarcinoma and in high-grade prostatic intraepithelial neoplasia. Histopathology 2006; 47:597-601. [PMID: 16324197 DOI: 10.1111/j.1365-2559.2005.02300.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS To analyse annexin I expression in prostatic carcinoma. Annexin I belongs to a family of structurally related calcium and phospholipid-binding proteins implicated in signal transduction, DNA replication, cell proliferation and apoptosis. The decreased expression of annexin I, II and VII proteins has been reported in different types of cancer. METHODS AND RESULTS Using immunohistochemistry, we analysed annexin I expression in 77 cases of prostatic adenocarcinoma (Gleason score 6, N = 40; Gleason scores 7-8, N = 27; and Gleason scores 9-10, N = 10) and high-grade prostatic intraepithelial neoplasia (PIN, N = 50). Immunoreactivity of annexin I in tumour cells was evaluated as negative (< 5% of cells), focally positive (5-25% of cells) or positive (> 25% of cells). In contrast to positive staining in adjacent benign prostatic epithelium, annexin I expression was decreased (focally positive) in 76% of cases of high-grade PIN (P < 0.0001) and was decreased or absent in 81% of prostatic adenocarcinomas (P < 0.0001). Annexin I expression in all higher grade tumours (Gleason scores 7-10) was only focally positive or absent. CONCLUSIONS Expression of annexin I inversely correlates with the increasing histological grade of prostatic adenocarcinoma. By showing a progressive loss of annexin I expression in high-grade PIN, intermediate-grade and high-grade cancer, our findings suggest that the loss of annexin I expression occurs early in prostatic tumorigenesis and becomes more prominent throughout tumour progression. The loss of expression of annexin I may serve as a useful marker of prostate cancer development and progression.
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Lin J, Yan XJ, Zheng L, Ma HH, Chen HM. Cytotoxicity and apoptosis induction of some selected marine bacteria metabolites. J Appl Microbiol 2005; 99:1373-82. [PMID: 16313410 DOI: 10.1111/j.1365-2672.2005.02741.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To study the potential apoptosis effects of cytotoxic marine bacterial metabolites on human HeLa cell line. METHODS AND RESULTS After HeLa cells were routinely cultured, tetrazolium-based colorimetric assay for cytotoxicity was performed to screen the marine bacteria extracts showing 12 strains active. To find the potential active strain with apoptosis mechanism, a battery of apoptosis assays, including AO/EB staining, TUNEL assay (terminal-deoxynucleotidyl transferase mediated nick end labelling), gel electrophoresis and flow cytometry, were used to determine whether apoptosis was involved in HeLa cell cytotoxicity of marine bacterial extracts. The results indicated that four strains could induce cell shrinkage, cell membrane blebbing, formation of apoptotic body and DNA fragmentation. CONCLUSIONS Crude extracts of 12 of 153 strains of marine bacteria showed cytotoxic effects with ID50 ranged from 77.20 to 199.84 microg ml(-1), in which eight strains of bacteria were associated bacteria. The metabolites in the strains of QD1-2, NJ6-3-1, NJ1-1-1 and SS6-4 were able to induce HeLa cells apoptosis. Furthermore, the assessment by flow cytometry indicated that the hypodiploid apoptotic cells increased in a time-dependent manner, suggesting that induced apoptosis occurred from 24 h to 48 h after the extracts treatment. SIGNIFICANCE AND IMPACT OF THE STUDY Our results suggested that the compounds from fermentation in these four marine bacterial strains could be candidates for developing apoptosis specific anti-tumour agents with lower toxicity. This study indicated that associated marine bacteria could be good source to find cytotoxic metabolites, and some cytotoxic marine bacterial metabolites could have apoptosis mechanisms.
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Chen YF, Lee CS, Lin CC, Su SF, Chen ML, Hsieh CC, Chen HM, Chiu CC, Lu YH, Liang HY, Yen HW, Hwang YS, Lin YT. Twenty-year follow-up of the Carpentier-Edwards standard porcine bioprosthesis in the Oriental population. THE JOURNAL OF CARDIOVASCULAR SURGERY 2003; 44:691-9. [PMID: 14735029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
AIM The 20-year period long-term results of porcine bioprosthetic valve use are limited. In addition, the majority of these reports come from Western countries. Given the scanty information reported in Oriental countries, this study was therefore designed to examine 20-year long-term results in patients who received a Carpentier-Edwards porcine bioprosthetic valve in an effort to contribute further information on the long-term clinical performance of porcine prosthetic valves from a viewpoint of results in the Oriental population. METHODS From July 1979 to April 2001, 82 patients received valve replacement with a standard Carpentier-Edwards porcine valve. There were 40 men and 42 women with a mean age of 42.3+/-15.1 years (range 16 to 73 years). Follow-up time extended more than 20 years (mean 10.9+/-3.2 years, range 0.5 to 21.5 years ) for a total of 719.5 patient-years. RESULTS The overall operative mortality was 16.9% (14 of 83 procedures). At 5, 10, 15, and 20 years, the actuarial survival rate of patients was 71.7%, 66.9%, 55.5%, and 44.4%, respectively. Actuarial estimates of freedom from structural valvular deterioration (SVD) at 5, 10, 15, and 17 years were 96.3%, 64.0%, 24.3%, and 24.3%, respectively; from reoperation 96.3%, 64.5%, 24.5%, and 24.5%; from operated valvular endocarditis 96.8%, 92.6%, 92.6%, and 92.6%; and from overall thromboembolism 96.3%, 88.5%, 67.2%, and 52.2%. In normal sinus rhythm, actuarial estimates of freedom from thromboembolism at 5, 10, 15, and 17 years were 100.0%, 100.0%, 81.8%, and 81.8%, respectively. Whereas for those in patients with atrial fibrillation, the estimates of freedom from thromboembolism were 94.5%, 82.4%, 57.7%, and 38.5%. CONCLUSION This study demonstrates the very satisfactory 20-year period long-term performance of freedom from bleeding events, thromboembolism (except in patients with atrial fibrillation), and valvular endocarditis in Oriental patients undergoing replacement with a porcine valve. However, the remarkable rate of SVD and reoperation ensued at 6 years after bioprosthesis implanted which does not differ from the series reported from Western countries.
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Chen KS, Wang WC, Chen HM, Lin CF, Hsu HC, Kao JH, Hu MT. Motorcycle emissions and fuel consumption in urban and rural driving conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2003; 312:113-122. [PMID: 12873404 DOI: 10.1016/s0048-9697(03)00196-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This work reports sampling of motorcycle on-road driving cycles in actual urban and rural environments and the development of representative driving cycles using the principle of least total variance in individual regions. Based on the representative driving cycles in individual regions, emission factors for carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NO(x)=NO+NO(2)) and carbon dioxide (CO(2)), as well as fuel consumption, were determined using a chassis dynamometer. The measurement results show that the representative driving cycles are almost identical in the three largest cities in Taiwan, but they differ significantly from the rural driving cycle. Irrespective of driving conditions, emission factors differ insignificantly between the urban and rural regions at a 95% confidence level. However, the fuel consumption in urban centers is approximately 30% higher than in the rural regions, with driving conditions in the former usually poor compared to the latter. Two-stroke motorcycles generally have considerably higher HC emissions and quite lower NO(x) emissions than those of four-stroke motorcycles. Comparisons with other studies suggest that factors such as road characteristics, traffic volume, vehicle type, driving conditions and driver behavior may affect motorcycle emission levels in real traffic situations.
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Wang MC, Chen HM. Forms and distribution of selenium at different depths and among particle size fractions of three Taiwan soils. CHEMOSPHERE 2003; 52:585-593. [PMID: 12738296 DOI: 10.1016/s0045-6535(03)00240-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The bioavailability of selenium in soils for plants depends more on its forms than on its total concentration. The purpose of the present study was to examine the solid-phase forms of selenium at different depths of three soil series representing major farming soil groups in Taiwan as well as the amounts of selenium in sand, silt and clay fractions of the soils. The study was conducted by means of sequential extraction to obtain the amounts of selenium and the distribution of various solid-phase forms of selenium at different depths of Pinchen (121 degrees 11(')E, 24 degrees 55(')N), Toulun-Sheto (120 degrees 55(')E, 24 degrees 50(')N), and Chunliao (120 degrees 25(')E, 23 degrees 57(')N) soil series. The amounts of metal oxide-bound form of selenium in the three soil series were the largest, with those of Pinchen and Toulun-Sheto soil series exceeding 50% of the total amounts of selenium and that of Chunliao soil series maintained at 30-40%. In the Pinchen and Toulun-Sheto soil series, the amounts of selenium in clay fractions were the largest, with a significant difference between the clays with and without metal oxides and organic matter removed. The amounts of selenium remained high in silt and/or sand fractions of the Chunliao soil series with metal oxides and organic matter removed. Metal oxide and organic matter contents of the three soil series mainly affect the amounts of various solid-phase forms of selenium and their distribution in different depths and particle size fractions of the soils. This observation of selenium associated with soil constituents was in good agreement with the results of the adsorption of selenite and selenate by the three soil series.
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Lin Q, Chen YX, Chen HM, Yu YL, Luo YM, Wong MH. Chemical behavior of Cd in rice rhizosphere. CHEMOSPHERE 2003; 50:755-761. [PMID: 12688487 DOI: 10.1016/s0045-6535(02)00216-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Chemical behavior of Cd in rice rhizosphere as affected or not by Pb was investigated. The NH4OAc extractable Cd in the rhizosphere was distinctly lower than that in bulk soil. The depletion of Cd in the rhizosphere could not be simply attributed to Cd uptake by rice. The observed phenomena could be attributed to the decreasing pH in the rhizosphere and the complexing capabilities of soluble exudates for Cd. Extractable Cd increased in both the rhizosphere and bulk soil after the addition of Pb, which might be caused by the replacement of Pb for Cd. The extractable Cd in the non-rhizosphere varied with the distance from the root surface, especially within 0-1 mm, which was greatly affected by the combined effects of mass flow, activation and fixation, and had the lowest extractable Cd. Pb addition affected the distribution of extractable Cd in the non-rhizosphere, implying that the affinity of Pb for organic matter was greater than that of Cd. The difference of Cd species between rhizosphere and bulk soil demonstrated that the transformation of exchangeable Cd (EXC-Cd) to OM-Cd (bound to organic matter) and FMO-Cd (bound to iron and manganese oxide) occurred in the rice rhizosphere due to the exudations from the rice root, the activity of microorganisms on the root surface and the activation of Fe and Mn oxides. The interaction between Pb and Cd resulted in the content of EXC-Cd being higher in the presence of Pb, whereas the OM-Cd content was lower in the presence of Pb.
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Chen HM, Sunamura M, Shibuya K, Yamauchi JI, Sakai Y, Fukuyama S, Mikami Y, Takeda K, Matsuno S. Early microcirculatory derangement in mild and severe pancreatitis models in mice. Surg Today 2002; 31:634-42. [PMID: 11495159 DOI: 10.1007/s005950170098] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
An in vivo microscopic technique was used to clarify the increase in microvascular permeability and enhanced leukocyte-endothelium interaction of pancreatic microcirculation in experimental pancreatitis of differing severity. Using bovine albumin fluorescein isothiocyanate (FITC) and carboxyfluorescein diacetate succinimidyl ester (CFDASE) as tracers, the change in permeability and the behavior of leukocytes in the acinar microcirculation were quantified during the initial 1, 2, 6, and 12h after the induction of caerulein pancreatitis in mice. Cold stress was added to produce the severe model. It was revealed that the early microcirculatory changes in the pancreas of caerulein pancreatitis included the increased permeability of endothelial lining and an accumulation of extravasated fluid in the perilobular space, which were more severe if cold stress was added. A decrease in flow velocity was also noted 2h after the onset of severe pancreatitis. Leukocyte adherence to the endothelial cells was not observed during the first 12h in either model of severity. In contrast, observation of the hepatic microcirculation revealed a significant number of adherent leukocytes 2h after the induction of severe pancreatitis. These results suggest that during the early course of acute pancreatitis, leukocyte adherence in the pancreatic microcirculation is a secondary event following the increase in pancreatic vascular permeability.
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Wang J, Lo JC, Foster A, Yu P, Chen HM, Wang Y, Tamada K, Chen L, Fu YX. The regulation of T cell homeostasis and autoimmunity by T cell-derived LIGHT. J Clin Invest 2001; 108:1771-80. [PMID: 11748260 PMCID: PMC209470 DOI: 10.1172/jci13827] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Costimulatory molecules on antigen-presenting cells (APCs) play an important role in T cell activation and expansion. However, little is known about the surface molecules involved in direct T-T cell interaction required for their activation and expansion. LIGHT, a newly discovered TNF superfamily member (TNFSF14), is expressed on activated T cells and immature dendritic cells. Here we demonstrate that blockade of LIGHT activity can reduce anti-CD3-mediated proliferation of purified T cells, suggesting that T cell-T cell interaction is essential for this proliferation. To test the in vivo activity of T cell-derived LIGHT in immune homeostasis and function, transgenic (Tg) mice expressing LIGHT in the T cell lineage were generated. LIGHT Tg mice have a significantly enlarged T cell compartment and a hyperactivated peripheral T cell population. LIGHT Tg mice spontaneously develop severe autoimmune disease manifested by splenomegaly, lymphadenopathy, glomerulonephritis, elevated autoantibodies, and severe infiltration of various peripheral tissues. Furthermore, the blockade of LIGHT activity ameliorates the severity of T cell-mediated diseases. Collectively, these findings establish a crucial role for this T cell-derived costimulatory ligand in T cell activation and expansion; moreover, the dysregulation of T cell-derived LIGHT leads to altered T cell homeostasis and autoimmune disease.
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Leung KW, Liaw YC, Chan SC, Lo HY, Musayev FN, Chen JZ, Fang HJ, Chen HM. Significance of local electrostatic interactions in staphylococcal nuclease studied by site-directed mutagenesis. J Biol Chem 2001; 276:46039-45. [PMID: 11598114 DOI: 10.1074/jbc.m106620200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this paper, we show that amino acids Glu(73) and Asp(77) of staphylococcal nuclease cooperate unequally with Glu(75) to stabilize its structure located between the C-terminal helix and beta-barrel of the protein. Amino acid substitutions E73G and D77G cause losses of the catalytic efficiency of 24 and 16% and cause thermal stability losses of 22 and 26%, respectively, in comparison with the wild type (WT) protein. However, these changes do not significantly change global and local secondary structures, based on measurements of fluorescence and CD(222 nm). Furthermore, x-ray diffraction analysis of the E75G protein shows that the overall structure of mutant and WT proteins is similar. However, this mutation does cause a loss of essential hydrogen bonding and charge interactions between Glu(75) and Lys(9), Tyr(93), and His(121). In experiments using double point mutations, E73G/D77G, E73G/E75G, and E75G/D77G, significant changes are seen in all mutants in comparison with WT protein as measured by fluorescence and CD spectroscopy. The losses of thermal stability are 47, 59, and 58%, for E73G/D77G, E73G/E75G, and E75G/D77G, respectively. The triple mutant, E73G/E75G/D77G, results in fluorescence intensity and CD(222 nm) close to those of the denatured state and in a thermal stability loss of 65% relative to the WT protein. Based on these results, we propose a model in which significant electrostatic interactions result in the formation of a locally stable structure in staphylococcal nuclease.
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Chiu CJ, Chiang CP, Chang ML, Chen HM, Hahn LJ, Hsieh LL, Kuo YS, Chen CJ. Association between genetic polymorphism of tumor necrosis factor-alpha and risk of oral submucous fibrosis, a pre-cancerous condition of oral cancer. J Dent Res 2001; 80:2055-9. [PMID: 11808761 DOI: 10.1177/00220345010800120601] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Many cytokines have been thought to play important roles in the pathogenesis of oral submucous fibrosis (OSF), an areca nut chewing-specific pre-cancerous condition characterized by the deposition of collagen in oral submucosa. Tumor necrosis factor-alpha (TNF-alpha), situated in the class III region of human leukocyte antigen (HLA), is a mediator with multiple functions, including the regulation of inflammatory reaction and transcriptions of collagen and collagenase. In total, 809 male subjects were recruited for assessment of the association of OSF with a bi-allelic promoter-region (-308) polymorphism on the TNFA gene. The high production allele, TNF2, was significantly lower among OSF subjects (n = 166) than in areca-chewing controls (n = 284). This association was independent of oral cancer status. The multivariate-adjusted odds ratio for the TNFA 11 genotype was 2.6 (95% confidence interval = 1.4-4.9; p = 0.004). The finding may imply a multifunctional etiological factor of TNF-alpha in OSF pathogenesis.
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Chen MF, Chen JC, Chiu DF, Ng CJ, Shyr MH, Chen HM. Prostacyclin analogue (OP-2507) induces delayed ex vivo neutrophil apoptosis and attenuates reperfusion-induced hepatic microcirculatory derangement in rats. Shock 2001; 16:473-8. [PMID: 11770047 DOI: 10.1097/00024382-200116060-00012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Leukocyte-endothelial adherence and changes of blood flow in microcirculation are associated with the development of ischemia-reperfusion injury in the liver. Polymorphonuclear neutrophil (PMN) apoptosis is essential to maintain homeostasis and plays a major role in limiting the reperfusion-related systemic effects. This study investigates the effects of a prostacyclin analogue (OP-2507) on hepatic ischemia-reperfusion injury. Adult, male Sprague-Dawley rats were used. Five groups were evaluated: (1) sham-operated control, n = 8; (2) ischemia control (1-h ischemia, 5-h reperfusion), n = 8; (3) intravenous infusion with OP-2507 ([15 cis-14-propylcyclohexyl]-16,17,18,19,20-pentanor-9-deoxy-9alpha,6-ni-trilo-PGF, methyl eater) at a dose of 1 microg/kg/min plus ischemia, n = 8; (4) intravenous infusion with OP-2507 at a dose of 0.1 microg/kg/min plus ischemia, n = 8, and (5) sham-operated control and intravenous infusion with OP-2507 at a dose of 1 microg/kg/min, N =8. Laser-Doppler flowmetry and an in vivo microscopy were used to investigate hepatic microcirculation. PMN apoptosis was quantitated by flow-cytometric labeling of DNA strand breaks. Tissue malondialdehyde and adenosine triphosphate were determined at the end of the experiment. Compared with the ischemia control group, OP-2507 significantly improved harmful insults following ischemia-reperfusion. The changes of mean systemic arterial pressure following ischemia-reperfusion have been significantly attenuated by OP- 2507 at both doses. OP-2507 lessened adherent leukocyte count in the post-sinusoid venules, and improved flow velocity in these areas. OP-2507 at both doses reduced malondialdehyde and increased adenosine triphosphate levels and this effect was dose-related. The activity of delayed ex vivo PMN apoptosis was significantly lower in the ischemia group than that of control and treatment groups. OP-2507 induced the activity of PMN apoptosis and its effect is dose-related, also. The PMN apoptosis activity is strongly correlated with parenchymal damages. This study demonstrates that OP-2507 treatment with ischemia may ameliorate the ischemia-reperfusion injury of the liver in the rat model, and increase spontaneous neutrophil apoptosis ex vivo.
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Tsai SJ, Wu MH, Lin CC, Sun HS, Chen HM. Regulation of steroidogenic acute regulatory protein expression and progesterone production in endometriotic stromal cells. J Clin Endocrinol Metab 2001; 86:5765-73. [PMID: 11739437 DOI: 10.1210/jcem.86.12.8082] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The regulation of steroidogenic acute regulatory protein (StAR) gene expression and the synthesis of steroids from cholesterol in ectopic endometriosis tissues were investigated. Peritoneal fluid and endometrial tissues were collected from patients with endometriosis and otherwise healthy women. Peritoneal progesterone and 17 beta-E2 concentrations were highest in early stage endometriosis compared with those in advanced stage endometriosis and in normal women. In concordance with the profile of peritoneal steroids, StAR mRNA and protein were greatest in ectopic implants of early endometriosis. In the advanced stage, concentrations of StAR mRNA and protein were also greater compared with those in normal endometrium. In contrast, P450 side-chain cleavage enzyme and 3 beta-hydroxysteroid dehydrogenase transcripts were not different between normal endometrium and ectopic endometriotic implants. Expression of StAR mRNA was detected in purified stromal, but not epithelial, cells. Treatment with PGE(2), but not TNF alpha, or IL-1 beta significantly increased StAR expression and thus induced progesterone production in cultured endometriotic stromal cells. These results demonstrated that aberrant expression of StAR in ectopic endometriotic tissues leading to increased peritoneal progesterone is associated with the formation of endometriosis. Induction of StAR gene expression by peritoneal PGE(2) in endometriotic stromal cells may further contribute to the development of endometriosis.
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Hsu JT, Chen HM, Jan YY, Chen MF. Chronic pancreatitis with pancreas divisum treated with pylorus-preserving pancreatoduodenectomy: a case report. HEPATO-GASTROENTEROLOGY 2001; 48:1770-1. [PMID: 11813621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Pancreas divisum, the most common congenital variant of pancreatic ductal anatomy, occurs when the ventral and dorsal pancreatic-buds fail to fuse. Herein, we report on a 42-year-old male suffering from chronic pancreatitis with pancreas divisum. Magnetic resonance cholangiopancreatography confirmed this diagnosis. A pylorus-preserving pancreatoduodenectomy was then performed. Pathological examination of the pancreas demonstrated chronic pancreatitis without malignancy. The postoperative clinical course was uneventful, and the patient was discharged 10 days after surgery.
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