Human infection with the novel pandemic influenza A (H1N1) virus was first identified in April 2009. Two months later, the World Health Organization (WHO) had raised the pandemic level to phase 6. Rapid case identification is essential for prompt patient management and public health actions. This study developed real-time and conventional reverse transcription-polymerase chain reaction (rRT-PCR and cRT-PCR) assays for pandemic H1N1 detection, and compared their sensitivities with protocols developed by WHO reference centres. Altogether, three rRT-PCR and one cRT-PCR targeting the matrix gene for universal detection of influenza A; three rRT-PCR, one cRT-PCR targeting the hemagglutinin (HA) gene for specific detection of pandemic H1N1; and one multiplex cRT-PCR for differentiating co-circulating seasonal H1N1, H3N2, and pandemic H1N1 were examined. The lower detection limit ranged from 1.252 to 125.2 copy equivalents. In general, rRT-PCR assays were more sensitive than cRT-PCR assays. All assays showed 100% sensitivity for "optimal" specimens (nasopharyngeal samples collected within 4 days after illness onset). For the other 36 samples, cRT-PCR assays were less sensitive except that the new Protocol I-cRT-pdmH1 still retained 100% sensitivity. The new Protocol F-rRT-PCR-pdmH1 was the only pandemic virusspecific rRT-PCR assay with 100% sensitivity across all specimen categories. In conclusion, rRT-PCR assays are 10-fold more sensitive than cRT-PCR assays. The newly developed cRT-PCR assay targeting the HA gene allows rapid, specific, and sensitive screening of this novel agent, which can serve as an alternative for laboratories where a real-time PCR machine is not available. © 2010 Wiley-Liss, Inc.

Waiyip Lam    Tingfan Leung    李礼舜    Cheung Jo L. K.    Applecm Yeung    Ho Yolanda I. I.    Chan Rickjason C.W.    Kitty Fung    Ian george Barr    David Hui    沈祖堯     Paul ks Chan   

Journal of Medical Virology

2010

A newly designed insulated angulotome was evaluated in a series of patients in whom biliary cannulation using conventional methods had failed and who required precut sphincterotomy. The new device consists of an insulated glass tip to prevent excessive electrocautery flow, and angulation to facilitate elevation of the papillary roof on cutting. A prospective series of patients with cholangitis or obstructive jaundice with failed biliary cannulation were recruited. The success of cannulation and complications following endoscopic retrograde cholangiopancreatography were analyzed. A total of 13 patients underwent precut sphincterotomy using the insulated angulotome. The immediate success of gaining biliary access after failed cannulation was 100%. The mean size of the common bile duct on ultrasonography was 8.1mm. The mean time to achieve biliary cannulation was 9 minutes 4 seconds, and there was no perforation or bleeding. This case series showed that precut sphincterotomy with the insulated angulotome can be safely performed without major complications. © Georg Thieme Verlag KG Stuttgart ? New York.

赵伟仁    Enders kwok wai Ng    Anthony Teoh    Simon Wong    沈祖堯     James Lau   

Endoscopy

2010

Approximately 30%-40% of patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B treated with peginterferon and/or lamivudine achieve HBeAg seroconversion 6 months after the end of treatment. The durability and long-term effect of treatment are unknown. In this study, 85 HBeAg-positive patients who received peginterferon alfa-2b 1.5 μg/kg/week for 32 weeks and lamivudine 100 mg/day for 52 or 104 weeks were prospectively followed for 6.1 ± 1.7 years posttreatment. Twenty-five (29%) patients had virologic response (HBeAg seroconversion and HBV DNA <10,000 copies/mL) at 5 years. The rate of HBeAg seroconversion rose progressively from 37% at the end of treatment to 60% at 5 years. Twenty-seven (32%) and 11 (13%) patients had undetectable HBV DNA (<100 copies/mL) at the end of peginterferon treatment and at 5 years, respectively. Two (2.4%) patients achieved hepatitis B surface antigen (HBsAg) seroclearance at 2.6 and 84 months posttreatment. Among virologic responders at the end of treatment, 82% and 57% and sustained HBeAg seroconversion and virologic response at 5 years. End-of-treatment serum quantitative HBsAg was significantly lower in patients with sustained virologic response at 5 years (median 1,431 IU/mL versus 2,689 IU/mL [P = 0.041]). At the last follow-up, the liver stiffness measurement by transient elastography was 5.8 ± 2.7 kPa. Only two patients had liver stiffness suggestive of advanced fibrosis. Week 16 HBV DNA, end-of-treatment HBeAg seroconversion, and undetectable HBV DNAwere independent factors associated with virologic response at 5 years. The duration of concomitant lamivudine treatment had no impact on any long-term response. Conclusion: Peginterferon has high durability in HBeAg-positive chronic hepatitis B patients with end-of-treatment virologic response. Copyright © 2010 by the American Association for the Study of Liver Diseases.

Vincent Wong    Grace Wong    Yan Kenneth Kar-Lung    Angel mei ling Chim    Hoiyun Chan    谢志恒    |蔡祥龙    Anthony wing hong Chan    沈祖堯     Henry lik yuen Chan   

Hepatology

2010

Although peroxisome proliferator-activated receptor gamma (PPARγ) agonist have been shown to inhibit hepatocellular carcinoma (HCC) development, the role of PPARγ in hepatocarcinogenesis remains unclear. We investigated the therapeutic efficacy of PPARγ against HCC. PPARγ-deficient (PPARγ) and wild-type (PPARγ) littermates were used in a diethylnitrosamine (DEN)-induced HCC model and treated with PPARγ agonist (rosiglitazone) or the vehicle alone for 8 months. The effects of PPARγ on HCC cell growth and apoptosis were examined using PPARγ-expressing adenovirus (Ad-PPARγ). PPARγ mice were more susceptible to DEN-induced HCC than PPARγ mice (94% versus 62%, P < 0.05), and rosiglitazone significantly reduced the incidence of HCC in PPARγ mice (vehicle 62% versus treatment 24%, P < 0.01), but not in PPARγ mice, indicating that PPARγ suppresses hepatocellular carcinogenesis. A pronounced expression of PPARγ was observed in a HCC cell line (Hep3B) infected with Ad-PPARγ. Such induction markedly suppressed HCC cell viability (P < 0.01). Further, Hep3B infection with Ad-PPARγ revealed a decreased proportion of cells in S-phase (12.92% versus 11.58%, P < 0.05), with arrest at G/M phase (38.2% versus 55.68%, P < 0.001), and there was concomitant phosphorylation of the key G/M phase inhibitors cdc25C and cdc2. PPARγ overexpression increased cell apoptosis (21.47% versus 35.02%, P < 0.01), mediated by both extrinsic (Fas and tumor necrosis factor-α) and intrinsic (caspase-9, caspase-3, caspase-7, and poly[ADP-ribose] polymerase) pathways. Moreover, PPARγ directly induced a putative tumor suppressor gene, growth differentiation factor-15. Conclusion: Loss of one PPARγ allele is sufficient to enhance susceptibility to HCC. PPARγ suppresses tumor cell growth through reducing cell proliferation and inducing G/M phase arrest, apoptosis, and up-regulating growth differentiation factor-15. Thus, PPARγ acts as a tumor-suppressor gene in the liver. Copyright © 2010 by the American Association for the Study of Liver Diseases.

Jun Yu    Bo Shen    Eagle Chu    Teoh Narci C.    Kinfai Cheung    Wu    Shiyan Wang    Lam Cleo N. Y.    Feng Hai    赵军红    Alfred Cheng    Kafai To    Henry lik yuen Chan    沈祖堯    

Hepatology

2010

Background Preferences to choose immunochemical faecal occult blood test (FIT) and colonoscopy as colorectal cancer (CRC) screening modalities among asymptomatic Chinese subjects remain unknown. Aim To evaluate the preference of choosing colonoscopy vs. FIT among CRC screening participants. Methods From a community-based CRC screening programme for asymptomatic Hong Kong Chinese aged 50-70 years, participants attended standardized educational sessions and chose the options of annual FIT for 5 years or direct colonoscopy once. Factors associated with choosing colonoscopy were evaluated by multivariate regression analysis. Results Among 3430 participants [mean age 56.8 years (s.d. 5.0); female 55.1%, male 44.9%], 51.3% chose colonoscopy and 48.7% chose FIT. Older participants (65-70 years) were less likely to choose colonoscopy [adjusted odds ratio (aOR) 0.731, P = 0.041]. Subjects who chose colonoscopy were those disagreed screening would lead to discomfort (aOR 1.356, P < 0.001), had relatives or friends who had CRC (first degree relatives aOR 1.679, P < 0.001; second degree relatives aOR 1.304, P = 0.019; friends or others aOR 1.252, P = 0.026) and those who self-perceived their health as poor (aOR 1.529, P = 0.025). Conclusions Faecal occult blood test and direct colonoscopy were equally preferable to Chinese. Colonoscopy was preferred among the younger subjects, those with positive family history of CRC and self-perceived poor health status. © 2010 Blackwell Publishing Ltd.

黄至生    Kelvin kf Tsoi    Simon siu man Ng    Lou Vivian W.Q.    蔡玉萍    Ling    Francis Chan    Siân meryl Griffiths    沈祖堯    

Alimentary Pharmacology and Therapeutics

2010

Resveratrol exhibits anti-tumor properties against different types of cancer. In this study, several polyhydroxylated resveratrol derivatives were prepared with the aim of discovering new leading compounds with clinical potential for human colon cancer chemotherapy. Among these compounds, 3,3',4,5,5'-pentahydroxy-. trans-stilbene (PHS) displayed the most potent cytotoxicity and triggered apoptosis in HT-29 cells as evidenced by increased poly(ADP-ribose) polymerase (PARP) cleavage, elevated levels of cytoplasmic nucleosomes and DNA fragmentation. Further mechanistic analysis revealed that PHS-induced apoptosis was caspase-dependent and mediated by its pro-oxidative action through up-regulation of reactive oxidative species generation and depletion of intracellular glutathione. © 2010 Elsevier B.V.

Haitao Li    William ka kei Wu    Zheng Zong-Ping    Chuntao Che    Li Zhi Jie    Xu    Clover ching man Wong    Ye Cai Guo    沈祖堯     Chihin Cho    Mingfu Wang   

European Journal of Pharmacology

2010

Chronic inflammation is the hallmark of the pathogenesis of Helicobacter pylori-induced gastric cancer. Interleukin (IL)-17A and IL-17F are inflammatory cytokines expressed by a novel subset of CD4+ Th cells and play critical function in inflammation and probably in cancer. We conducted a case-control study including 1,010 gastric cancer patients and 800 healthy controls to assess the association between IL-17A G197A and IL-17F A7488G polymorphisms and risk of gastric cancer. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing. Logistic regression and Cox-proportional hazards analyses were used to evaluate the associations between polymorphisms and gastric cancer susceptibility, clinicopathological features and survival. After adjusted for age and gender, IL-17F 7488GA and GG genotypes were associated with an increased risk of gastric cancer compared with AA genotype [OR 1.51, 95% confidence interval (CI): 1.22-1.87 for GA; OR 1.61, 95% CI: 1.03-2.51 for GG]. Further stratification analyses indicated that the effect of IL-17F 7488GA genotype was noteworthy in gastric cancer patients of noncardia, intestinal type, poorly and moderately differentiated, age older than 40, large tumor size and lymph node metastasis. IL-17A 197AG genotype was associated with increased risk of poorly differentiated, TNM I/II, age of 40-65-year subtypes of gastric cancer, but not with total gastric cancer risk (p = 0.098). No significant relationship was observed between polymorphisms and survival of gastric cancer patients. These findings suggest that polymorphism of IL-17F 7488 involved in susceptibility to gastric cancer, which also influenced certain subtypes according to clinicopathological features, whereas IL-17A 197 may be less relevant. © 2009 UICC.

Wu Xiaoqin    曾志荣    Chen Bin    Jun Yu    Ling Xue    郝元涛    陈旻湖    沈祖堯     Pinjin Hu   

International Journal of Cancer

2010

Peroxisome proliferator-activated receptor-γ (PPARγ) is a transcription factor that regulates lipid metabolism and inflammatory responses. Certain PPARγ ligands improve nonalcoholic steatohepatitis (NASH). The role of PPARγ itself in NASH remains poorly understood. The functional consequences of PPARγ in the development of steatohepatitis through gene deficiency or gene overexpression of PPARγ delivered by adenovirus (Ad-PPARγ) were examined. Our results show that PPARγ-deficient (PPARγ/) mice fed the methionine-and choline-deficient (MCD) diet developed more severe steatohepatitis than wild-type mice, and were unaffected by PPARγ ligand rosiglitazone. Overexpression of PPARγ delivered by Ad-PPARγ attenuated steatohepatitis. This effect was associated with redistribution of fatty acid from liver to adipose tissue by enhancing expression of fatty acid uptake genes (fatty acid binding protein-4 (aP2), fatty acid translocase (CD36), lipoprotein lipase (LPL) and fatty acid transport protein-1 (FATP-1)) and lipogenic genes (sterol regulatory element binding protein isoform-1 (SREBP-1) and stearoyl-CoA desaturase isoform-1 (SCD-1)) in adipose tissue and to a lesser extent in liver. The anti-steatohepatitis action of PPARγ was also mediated via regulating adipokines through suppressing tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and inducing adiponectin. Moreover, PPARγ activation suppressed hepatic lipoperoxide and reduced hepatic pro-inflammatory cytokines (TNF-α and IL-6) production. In conclusion, PPARγ is an important endogenous regulator and potential therapeutic target for nutritional steatohepatitis. © 2010 Macmillan Publishers Limited All rights reserved.

Wu    Eagle Chu    Lam Cleo N. Y.    Alfred Cheng    Chungwa Lee    Vincent Wong    沈祖堯     Jun Yu   

Gene Therapy

2010

A population-based telephone survey of acute gastroenteritis (AG) was conducted in Hong Kong from August 2006 to July 2007. Study subjects were recruited through random digit-dialling with recruitments evenly distributed weekly over the 1-year period. In total, 3743 completed questionnaires were obtained. An AG episode is defined as diarrhoea 3 times or any vomiting in a 24-h period during the 4 weeks prior to interview, in the absence of known non-infectious causes. The prevalence of AG reporting was 7%. An overall rate of 091 (95% CI 081-101) episodes per person-year was observed with women having a slightly higher rate (094, 95% CI 079-108) than men (088, 95% CI 073-104). The mean duration of illness was 36 days (s.d.=552). Thirty-nine percent consulted a physician, 19% submitted a stool sample for testing, and 26% were admitted to hospital. Of the subjects aged 15 ≥ years, significantly more of those with AG reported eating raw oysters (OR 24, 95% CI 13-44), buffet meals (OR 18, 95% CI 13-25), and partially cooked beef (OR 18, 95% CI 12-27) in the previous 4 weeks compared to the subjects who did not report AG. AG subjects were also more likely to have had hot pot, salad, partially cooked or raw egg or fish, sushi, sashimi, and snacks bought at roadside in the previous 4 weeks. This first population-based study on the disease burden of AG in Asia showed that the prevalence of AG in Hong Kong is comparable to that experienced in the West. The study also revealed some risky eating practices that are more prevalent in those affected with AG. Copyright © 2009 Cambridge University Press.

Suzanne Ho    Chau    Fung    Aprille Sham    Edmund anthony severn Nelson    沈祖堯    

Epidemiology and Infection

2010

Background: The aim of this study was to investigate factors affecting clinical outcomes of adults hospitalised with severe seasonal influenza. Methods: A prospective, observational cohort study was conducted over 24 months (2007-2008) in two acute, general hospitals. Consecutive, hospitalised adult patients were recruited and followed once their laboratory diagnosis of influenza A/B was established (based on viral antigen detection and virus isolation from nasopharyngeal aspirates collected per protocol). Outcomes studied included in-hospital death, length of stay and duration of oxygen therapy. Factors affecting outcomes were analysed using multivariate Cox proportional hazards models. Sequencing analysis on the neuraminidase gene was performed for available H1N1 isolates. Results: 754 patients were studied (influenza A, n=539; >75% H3N2). Their mean age was 70±18 years; comorbidities and serious complications were common (61-77%). Supplemental oxygen and ventilatory support was required in 401 (53.2%) and 41 (5.4%) patients, respectively. 39 (5.2%) patients died; pneumonia, respiratory failure and sepsis were the causes. 395 (52%) patients received antiviral (oseltamivir) treatment. Omission of antiviral treatment was associated with delayed presentation or negative antigen detection results. The mortality rate was 4.56 and 7.42 per 1000 patient-days in the treated and untreated patients, respectively; among those with co-morbidities, it was 5.62 and 11.64 per 1000 patient-days, respectively. In multivariate analysis, antiviral use was associated with reduced risk of death (adjusted HR (aHR) 0.27 (95% CI 0.13 to 0.55); p<0.001). Improved survival was observed with treatment started within 4 days from onset. Earlier hospital discharge (aHR 1.28 (95% CI 1.04 to 1.57); p=0.019) and faster discontinuation of oxygen therapy (aHR 1.30 (95% CI 1.01 to 1.69); p=0.043) was associated with early treatment within 2 days. Few (n=15) H1N1 isolates in this cohort had the H275Y mutation. Conclusions: Antiviral treatment for severe influenza is associated with reduced mortality and improved clinical outcomes.

李礼舜    Kinwing Choi    Paul ks Chan    David Hui    Grace Lui    Bonnie Wong    Rity Wong    Sin    Hui    Karry Ngai    Clive stewart Cockram    Raymond Lai    沈祖堯    

Thorax

2010