Lok-Beng Koay
Taipei Medical University
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Featured researches published by Lok-Beng Koay.
Clinical Cancer Research | 2007
Jaw-Yuan Wang; Shiu-Ru Lin; Deng-Chyang Wu; Chien-Yu Lu; Fang-Jung Yu; Jan-Sing Hsieh; Tian-Lu Cheng; Lok-Beng Koay; Yih-Huei Uen
Purpose: In this study, a high-sensitivity colorimetric membrane array method was used to detect circulating tumor cells (CTC) in the peripheral blood of colorectal cancer (CRC) patients with normal perioperative serum carcinoembryonic antigen (CEA) levels. This membrane array method was evaluated as a potential diagnostic and postoperative surveillance tool. Study Design: Membrane arrays consisting of a panel of mRNA markers that include human telomerase reverse transcriptase, cytokeratin-19, cytokeratin-20, and CEA mRNA were used to detect CTCs in the peripheral blood of 157 postoperative CRC patients with normal perioperative serum CEA levels and in 80 healthy individuals. Digoxigenin-labeled cDNA were amplified by reverse transcription-PCR from the peripheral blood samples, which were then hybridized to the membrane array. The sensitivity, specificity, and accuracy of membrane arrays for the detection of CTCs were then calculated. Results: Using the four markers in combination, expression of any three markers or all the four markers in this panel was significantly correlated with the clinicopathologic characteristics, including depth of tumor invasion, lymph node metastasis, tumor-node-metastasis stage, and postoperative relapse (all P < 0.05). The interval between the detection of all four positive molecular markers and subsequent elevated CEA ranged from 3 to 8 months (median 6 months). The expression of all four mRNA markers was an independent predictor for postoperative relapse. CRC patients with all four mRNA markers expression showed a significantly poorer survival rate than those with less than four positive markers. Conclusions: The constructed membrane array method was helpful in the early prediction of postoperative relapse in CRC patients with normal perioperative serum CEA levels.
Cancer Epidemiology, Biomarkers & Prevention | 2009
Hao-Hsien Lee; Yih-Huei Uen; Chi-Shu Sun; Ming-Jen Sheu; Hsing-Tao Kuo; Lok-Beng Koay; Ching-Yih Lin; Ching-Cherng Tzeng; Chia-Ju Cheng; Ling-Yu Tang; Sun-Lung Tsai; Andrew H.-J. Wang
Background: Up-regulation of Wnt-1 protein has been reported in hepatitis B virus (HBV)–related and hepatitis C virus (HCV)–related hepatocellular carcinoma (HCC) tissues and cell lines. It is known to play a fundamental role in signaling cancer progression, whereas its prognostic role in HCC remains unexplored. Methods: As a prognostic biomarker, this study analyzed Wnt-1 protein expression in 63 histology-verified HCC patients receiving curative resection. In each paired tumor and nontumor specimen, Wnt-1 levels were semiquantitatively measured by Western blotting and expressed by tumor/nontumor ratio. The data were further correlated with quantitative real-time PCR as well as with β-catenin and E-cadherin expression by immunohistochemistry. Cumulative tumor recurrence-free survival curves were constructed using the Kaplan-Meier method and compared by the log-rank test. Results: The results showed that 26 (group I) and 37 (group II) HCC patients had an expression ratio of Wnt-1 ≥1.5 and <1.5, respectively. The amount of Wnt-1 estimated by tumor/nontumor ratio correlated with the results by quantitative real-time PCR. High tumor Wnt-1 expression correlated with enhanced nuclear β-catenin accumulation, diminished membranous E-cadherin expression, and increased tumor recurrence after curative tumor resection. Conclusions: These results suggest that Wnt-1 may be used as a predisposing risk factor for HCC recurrence. The use of tumor Wnt-1 as prognostic biomarker may identify patients with HBV- and/or HCV-related HCC patients with a high risk of tumor recurrence who may then benefit from further intensive therapy after surgery. (Cancer Epidemiol Biomarkers Prev 2009;18(5):1562–9)
Journal of The Chinese Medical Association | 2007
Yih-Huei Uen; Yi Chen; Chen-Yi Kuo; Kuo-Chang Wen; Lok-Beng Koay
Background: Two alternative surgical techniques for elective laparoscopic cholecystectomy (LC), low‐pressure insufflation of the peritoneal cavity and abdominal wall lifting (AWL), have been developed over time to minimize the disadvantages associated with CO2‐elicited pneumoperitoneum. To the best of our knowledge, the 2 methods have seldom been compared as regards their relative advantages and disadvantages. Methods: Eighty patients scheduled for elective LC were randomized into either a low‐pressure (8 mmHg) CO2 insufflation method (LPLC) group, or a gasless technique using a subcutaneous abdominal wall lifting device (GLC group). The duration of the surgical procedure, the surgical results including level of postoperative pain, and perioperative cardiopulmonary function changes experienced by the members of both groups were compared. Results: Laparoscopic surgery was completed for all but 1 patient from each group due to an inadequate surgical‐site exposure. There was no mortality for study participants, and no major complications were noted for members of either group. The LPLC group evidenced a shorter surgical duration as compared to the GLC group (77 ± 28 minutes vs. 98 ± 27 minutes, respectively; p < 0.01) and a lower incidence of postoperative shoulder pain (2/38 vs. 8/39, respectively; p < 0.05), although significant differences in intraoperative pulmonary function were noted (an increased PaCO2, PetCO2 and peak‐airway pressure and decreased arterial blood pH; p < 0.01) for the LPLC group compared to the GLC group. Conclusion: Both alternative methods for this type of surgery appeared feasible and safe for LC. Low‐pressure CO2 pneumoperitoneum had a shorter surgical duration and less postoperative shoulder pain compared to the GLC technique, but did not feature any other advantage over the AWL technique with regard to impact on cardiopulmonary function.
Journal of Medical Virology | 2009
Kuan-Ta Wu; Kun-Ming Chung; I.-Che Feng; Ming-Jen Sheu; Hsing-Tao Kuo; Lok-Beng Koay; Chin-Yih Lin; Ling-Yu Tang; Sun-Lung Tsai
Sporadic cases of acute hepatitis E virus (HEV) infection with production of anti‐HEV IgM have been reported occasionally in Taiwan despite no reported outbreaks in the past. This study was undertaken to determine whether serological markers correlated with virus detection. From 2002 to 2006, 72 reported cases of acute hepatitis E seropositive for anti‐HEV IgM in Taiwan were enrolled for investigation. Acute phase serum samples were collected for detection of HEV RNA, HBV DNA, HCV RNA, and GBV‐C RNA by PCR. The results showed that viral sequences of HEV, HBV, HCV and GBV‐C were detected in 54 (75%), 21 (29.2%), 9 (12.5%), and 22 (30.6%) of cases, respectively. Acute hepatitis A co‐infection was excluded in all patients because none were seropositive for anti‐HAV IgM and, nine patients (12.5%) did not seroconvert to anti‐HEV IgG. These results suggest that serum markers did not correlate completely with viremia in the diagnosis of acute HEV infection. Multiple viruses may co‐infect with acute hepatitis E virus in Taiwan. Detection of hepatitis E viremia together with seropositivity for anti‐HEV IgM and followed by seroconversion to anti‐HEV IgG should be included in the diagnostic criteria for HEV infection. J. Med. Virol. 81:1734–1742, 2009.
Human Immunology | 2011
Lok-Beng Koay; I-Che Feng; Ming-Jen Sheu; Hsing-Tao Kuo; Chin-Yih Lin; Jyh-Jou Chen; Shih-Ling Wang; Ling-Yu Tang; Sun-Lung Tsai
Acute exacerbations (AEs) of chronic hepatitis B (CH-B) are thought to be the result of breakdown of immune tolerance on the natural history of chronic hepatitis B virus (HBV) infection. Immune tolerance to HBV maintained in CH-B patients without hepatitis is under the control of the hosts forkhead box p3-expressing regulatory T cells (Tregs). Its breakdown mimics the occurrence of autoimmune diseases. Severe AEs may lead to liver decompensation and mortalities. Consequently, AEs are currently the major therapeutic targets in patient treatment. In this study, we employed the SYFPEITHI scoring system to identify epitopes on HBV core antigen (HBcAg) for the construction of human leukocyte antigen class II tetramers to measure HBcAg-specific Treg frequencies (Tregf). Upregulation of Treg gene profiling accompanied by increased HBcAg-specific Tregf was detected in AE patients with sustained remission (SR) to anti-HBV therapy. Depletion of Tregs from peripheral blood mononuclear cells enhanced proliferation to HBcAg. HBcAg-specific Treg clones inhibited the killing capacity of cytotoxic T lymphocyte clones in an antigen-independent manner. A greater posttherapy increase in HBcAg-specific Tregf correlated with a higher SR rate to anti-HBV therapy. These results suggest that HBcAg-specific Tregs function as suppressor effectors and confer SR to anti-HBV therapy.
European Journal of Gastroenterology & Hepatology | 2009
Ming-Jen Sheu; Hsing-Tao Kuo; Ching-Yih Lin; Lok-Beng Koay; Chuan Lee; Jyh-Jou Chen; Ling-Yu Tang; Sun-Lung Tsai
Background Acute exacerbation (AE) of chronic hepatitis B virus (HBV) infection in cancer chemotherapy patients and in organ transplant recipients receiving immunosuppressants may cause catastrophe and high mortality. Hence, immediate treatment with nucleoside analogues for such patients has become a consensus. Anti-HBV therapeutic trials in Asia have shown that AE of chronic hepatitis B (CH-B) may result in increased sustained remission (SR) rate with lamivudine monotherapy. Nonetheless, AE episodes in CH-B patients may evolve uneventfully and lead to spontaneous remission. Thus, the policy of immediate anti-HBV therapy for AE patients reaches an impasse. Once treatment is initiated, life long HBV suppression may be necessary. Objective To determine whether lamivudine monotherapy during an AE of CH-B results in an increase in SR compared with no therapy. Methods A cohort of 154 CH-B patients seropositive for hepatitis B e antigen with AE formed the study group. This included 102 cases receiving a nationwide therapeutic trial of 18-month lamivudine monotherapy that were compared with 52 cases with no therapy. All were observed for at least 30 months, which encompassed the 18-month on treatment period and a 12-month posttreatment follow-up. Results No significant increase was observed in the SR rate in the lamivudine treatment group compared with the spontaneous remission rate in the untreated patients (P=0.782, Fishers exact test). Conclusion AE does not increase the SR rate during 18-month lamivudine monotherapy. Immediate lamivudine therapy for AE patients is not justified as mandatory. The policy should be only applied to AE patients with impending liver failure.
內科學誌 | 2015
Poh-Poo Lim; Lok-Beng Koay; Ching-Yih Lin; Ming-Jen Sheu; Hsing-Tao Kuo; Chi-Shu Sun; I-Che Feng; Yu-Min Lin; Ping-Hsin Hsieh
Liver abscess after hepatic artery embolization is a rare but serious complication associated with significant morbidity and mortality. Here we report a 52-year-old case of chronic hepatitis B, liver cirrhosis and diabetes mellitus (DM) type 2 with a large gas forming liver abscess (11.4 cm) developed after transarterial chemoembolization (TACE) treatment for a large hepatocellular carcinoma (HCC). The condition responded well to four weeks of antibiotics treatment plus percutaneous drainage with continuous abscess regression after treatment. Infection of the necrotic tumor seems to be the cause of abscess formation in this case. We suggest that for patient with large tumor size, multiple risk factors such as DM, liver cirrhosis, associated biliary disease and old age; post TACE abscess formation should be highly aware of, investigated early and treated promptly. Prophylaxis antibiotics may also be considered.
PLOS ONE | 2015
Yen-Ling Ko; Chi-Shu Sun; Kun-Ming Chung; Yu-Min Lin; I-Che Feng; Ming-Jen Sheu; Lok-Beng Koay; Ching-Yih Lin; Chung-Han Ho; Hsing-Tao Kuo
It has been observed that enlargement of perihepatic lymph nodes may be seen in patients with chronic hepatitis B, particularly during acute flares of CHB. We hypothesized that there may be a correlation between the nodal change patterns in CHB patients with acute flare and HBeAg status. Perihepatic lymph node sizes of 87 patients with acute flares of CHB were documented, with a median follow up of 43 months. Patients were separated into 3 groups, HBeAg-positive with HBe seroconversion (group 1), HBeAg-positive without HBe seroconversion (group 2), and HBeAg-negative (group 3). Group 1 has the highest incidence of enlarged lymph nodes (92.3%) compared with group 2 (75.8%) and group 3 (46.8%) (p = 0.003). And if nodal width at acute flare was > 8mm and interval change of nodal width was >3mm, the incidence of HBeAg seroconversion will be 75% (p<0.001). Conclusion Larger perihepatic lymph nodes are seen in CHB acute flare patients with positive HBeAg and the magnitude of nodal width change may predict HBeAg seroconversion at recovery.
European Journal of Gastroenterology & Hepatology | 2011
Yu-Min Lin; Ming-Jen Sheu; Hsing-Tao Kuo; I-Che Feng; Chi-Shu Sun; Lok-Beng Koay; Ching-Yih Lin
Background and aims In chronic hepatitis C, the change of perihepatic lymph nodal size after antiviral therapy could be a marker of virologic response. Whether the on-treatment nodal manifestations predict virologic responses is unknown. Methods Patients (n=88) with biopsy-proven chronic hepatitis C received standard doses of bi-therapy for 24 weeks; sequential changes of the perihepatic lymph nodes were evaluated prospectively by ultrasound. Pretreatment and on-treatment factors were analyzed and correlated with sustained virologic response, focusing on early on-treatment nodal changes (12 weeks). Results Perihepatic lymph nodes were prevalent in 75% of the patients; 72 patients (81.8%) achieved sustained viral response. Before treatment, no factor was significantly associated with the nodal prevalence or size. The pretreatment nodal width (mean 5.3 vs. 3.6 mm; P=0.023) and the on-treatment nodal manifestations including a reduction in nodal width at 12 weeks of antiviral treatment (median; 1.05 vs. 0 mm, P=0.029) and a reduction of nodal volume at the end of treatment (24 weeks; median 0.62 vs. −0.01 ml, P=0.015) were significantly correlated with the sustained virologic response. A reduction of nodal width greater than 2.5 mm at 12 weeks always predicts sustained virologic response (100 vs. 77%; P=0.019). Conclusion Results confirm the high prevalence of perihepatic lymphadenopathy in patients with chronic hepatitis C. The use of the nodal width measurement in routine ultrasound follow-up may be a simpler early predictor of sustained virologic response during standard bi-therapy.
World Journal of Gastroenterology | 2015
I.-Che Feng; Szu Jen Wang; Ming Jen Sheu; Lok-Beng Koay; Ching Yih Lin; Chung Han Ho; Chi Shu Sun; Hsing Tao Kuo
AIM To study the manifestations of perihepatic lymph nodes during the episode of acute hepatitis flare by point-of-care ultrasonography. METHODS One hundred and seventy-six patients with an episode of acute hepatitis flare (ALT value > 5 × upper normal limit) were enrolled retrospectively. Diagnosis of etiology of the acute hepatitis flare was based on chart records and serological and virological assays. The patients were categorized into two groups (viral origin and non-viral origin) and further defined into ten subgroups according to the etiologies. An ultrasonograpy was performed within 2 h to 72 h (median, 8 h). The maximum size of each noticeable lymph node was measured. Correlation between clinical parameters and nodal manifestations was analyzed RESULTS Enlarged lymph nodes (width ≥ 5mm) were noticeable in 110 (62.5%) patients, mostly in acute on chronic hepatitis B (54.5%). The viral group had a higher prevalence rate (89/110 = 80.9%) and larger nodal size (median, 7 mm) than those of the non-viral group (21/66 = 31.8%; median, 0 mm) (P < 0.001 for both). Meanwhile, there were significant differences in the nodal size between acute and chronic viral groups (P < 0.01), and between acute hepatitis A and non-hepatitis A viral groups (P < 0.001). In logistical regression analysis, the nodal width still showed strong significance in multivariate analysis (P < 0.0001) to stratify the two groups. The area under the curve of ROC was 0.805, with a sensitivity of 80.9%, a specificity of 68.2%, positive predictive value of 80.92%, negative predictive value of 68.18%, and an accuracy of 76.14%. CONCLUSION Point-of-care ultrasonography to detect perihepatic nodal change is valuable for clarifying the etiologies in an episode of acute hepatitis flare.