Christopher W K Lam

Macau University of Science and Technology, Macao, Macau, Macao

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Publications (150)638.3 Total impact

  • Ting F Leung · Iris H.S. Chan · Tak C Liu · Christopher W.K. Lam · Gary W.K. Wong
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    ABSTRACT: Environmental tobacco smoke (ETS) exposure is a risk factor for asthma in school-age children, but there is limited data of ETS exposure on respiratory health in preschool children. This study investigated the relationship between ETS, lead (Pb), and cadmium (Cd) exposures and asthma symptoms and spirometric indices in Chinese preschoolers. Preschool children from 30 nurseries and kindergartens performed spirometry with incentives of animation programs, and their urinary cotinine, Pb and Cd concentrations were measured by immunoassay and inductively coupled plasma-mass spectrometry, respectively. Two thousand seven hundred sixty-three preschoolers participated, and 1,505 and 893 provided valid spirometric data and urine samples, respectively. Current domestic smoking was reported in 37.5% of children, but only 95 (10.6%) had high urinary cotinine-to-creatinine ratio (≥30 ng/mg). Pb was measurable in 3.9% of samples, whereas 406 (45.5%) children had high Cd. Reported ETS exposure was not associated with any spirometric index, whereas cotinine-to-creatinine ratio was inversely associated with forced expiratory volume in 0.5-sec (β = -0.093, P = 0.003), forced expiratory flow between 25% and 75% of expiration (β = -0.138, P = 0.002) and peak expiratory flow (β = -0.106, P = 0.002). Cd exposure was not associated with reported respiratory symptom or spirometric indices. This community study shows that ETS exposure defined by urinary cotinine is a strong risk factor for lung function impairment measured by spirometry in Chinese preschool children. Urinary cotinine is more reliable than questionnaire for assessing ETS exposure in young children. Although high urinary Cd is common in Hong Kong preschoolers, such biomarker is not associated with any clinical or spirometric outcome. Pediatr Pulmonol. © 2013 Wiley Periodicals, Inc.
    No preview · Article · Nov 2013 · Pediatric Pulmonology
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    ABSTRACT: The role of serum α-fetoprotein (AFP) measurements in the diagnosis of hepatocellular carcinoma (HCC) remains controversial. Some guidelines have advised against the use of AFP in the diagnosis of HCC. This study was conducted to evaluate the performance of AFP in the diagnosis of HCC, and to identify the optimal cut-off value of serum AFP in the diagnosis of HCC in patients with a hepatic mass. Patients who presented during the period from May 1997 to March 2003 with hepatic lesions, for whom paired data on serum AFP values at baseline and lesion histology were available, were reviewed. The performance of AFP in the diagnosis of HCC was determined using receiver operating characteristic curve analysis. Data for a total of 805 patients were evaluated. The mean AFP value was 26 900 ng/ml (range: 0-1 965 461 ng/ml). The histological diagnosis was HCC in 557 patients. The optimal AFP cut-off value was 10 ng/ml (for sensitivity of 82.6% and specificity of 70.4%). At a cut-off level of 200 ng/ml, sensitivity, specificity, and positive and negative predictive values were 47.7%, 97.1%, 97.5% and 44.4%, respectively. The diagnostic performance of AFP remains similar in patients with chronic hepatitis B virus infection, despite a lower negative predictive value. Common aetiologies of liver lesions associated with elevated AFP include cholangiocarcinoma and neuroendocrine tumours. In Asian patients with suspicious liver lesions, the cut-off AFP level of 200 ng/ml is useful to achieve a diagnosis of HCC with high specificity and reasonable sensitivity. The measurement of serum AFP should not be excluded from guidelines for the diagnosis of HCC.
    No preview · Article · Aug 2013 · HPB
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    ABSTRACT: Pentaherb formula (PHF) has been proven to improve the quality of life of children with atopic dermatitis without side effects. The aim of this study was to elucidate the potential anti-inflammatory and anti-allergic activities of PHF, Moutan Cortex (Danpi/DP) and gallic acid (GA) using human basophils (KU812 cells), which are crucial effector cells in allergic inflammation. PHF, DP and GA could significantly suppress the expression of allergic inflammatory cytokine IL-33-upregulated intercellular adhesion molecule (ICAM)-1, and the release of chemokines CCL2, CCL5, CXCL8 and inflammatory cytokine IL-6 from KU812 cells (all p < 0.05). With the combined use of dexamethasone (0.01 μg/mL) and GA (10 μg/mL), the suppression of ICAM-1 expression and CCL5 and IL-6 release of IL-33-activated KU812 cells were significantly greater than the use of GA alone (all p < 0.05). The suppression of the IL-33-induced activation of intracellular signalling molecules p38 mitogen activated protein kinase, nuclear factor-kB and c-Jun amino-terminal kinase in GA-treated KU812 cells could be the underlying mechanism for the suppression on ICAM-1, chemokines and cytokines. The combined use of dexamethasone with the natural products PHF or DP or GA might therefore enhance the development of a novel therapeutic modality for allergic inflammatory diseases with high potency and fewer side effects.
    No preview · Article · Mar 2013 · Molecules
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    ABSTRACT: Background: A multicenter study conducted in Southeast Asia to derive reference intervals (RIs) for 72 commonly measured analytes (general chemistry, inflammatory markers, hormones, etc.) featured centralized measurement to clearly detect regionality in test results. The results of 31 standardized analytes are reported, with the remaining analytes presented in the next report. Method: The study included 63 clinical laboratories from South Korea, China, Vietnam, Malaysia, Indonesia, and seven areas in Japan. A total of 3541 healthy individuals aged 20-65 years (Japan 2082, others 1459) were recruited mostly from hospital workers using a well-defined common protocol. All serum specimens were transported to Tokyo at -80°C and collectively measured using reagents from four manufacturers. Three-level nested ANOVA was used to quantitate variation (SD) of test results due to region, sex, and age. A ratio of SD for a given factor over residual SD (representing net between-individual variations) (SDR) exceeding 0.3 was considered significant. Traceability of RIs was ensured by recalibration using value-assigned reference materials. RIs were derived parametrically. Results: SDRs for sex and age were significant for 19 and 16 analytes, respectively. Regional difference was significant for 11 analytes, including high density lipoprotein (HDL)-cholesterol and inflammatory markers. However, when the data were limited to those from Japan, regionality was not observed in any of the analytes. Accordingly, RIs were derived with or without partition by sex and region. Conclusions: RIs applicable to a wide area in Asia were established for the majority of analytes with traceability to reference measuring systems, whereas regional partitioning was required for RIs of the other analytes.
    No preview · Article · Feb 2013 · Clinical Chemistry and Laboratory Medicine
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    ABSTRACT: Aim: Cadmium (Cd) and lead (Pb) are toxic elements in our environment. This study is to determine the reference intervals of Cd and Pb in blood and urine from Hong Kong school children and to identify their determinants. Methods: A total of 2209 secondary school children and 893 preschool children were recruited. Cd and Pb in blood and urine were measured by inductively-coupled plasma mass spectrometry. Results: Blood Cd was affected by age, smoking and residential district, while urine Cd was influenced by age and blood Cd. Blood Cd was positively correlated with smoking as confirmed by urinary cotinine (rho = 0.183, p < 0.001, n = 2074). Blood Pb was dependent on gender and residential district, while urinary Pb was dependent on gender and blood Pb. Students from schools of lower academic grading had higher blood Cd and Pb than those from higher academic grading schools (p < 0.001, respectively). Urinary albumin was positively associated with urinary Cd and Pb. Conclusions: Using a non-occupationally exposed population, the reference ranges are: blood Cd < 21.9 nmol/L for smokers and < 8.8 nmol/L for non-smokers, and blood Pb < 203.8 nmol/L. Reference intervals for urinary Cd and Pb are also reported.
    No preview · Article · Oct 2012 · Pathology
  • Ting Fan Leung · Iris H.S. Chan · Tak Chi Liu · Gary W.K. Wong · Christopher W.K. Lam

    No preview · Conference Paper · May 2012
  • Miao Hu · Wei Lan · Christopher W K Lam · Ying Tat Mak · Chi Pui Pang · Brian Tomlinson
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    ABSTRACT: BACKGROUND: Earlier studies reported that Chinese subjects with heterozygous familial hypercholesterolemia (heFH) living in Mainland China or in Western countries had lower plasma low-density lipoprotein cholesterol (LDL-C) levels and lower prevalence of xanthomata or coronary heart disease (CHD) than Caucasians with heFH and a greater proportion went unrecognized. We characterized the features of Hong Kong Chinese with heFH identified by cascade screening. METHODS: Potential probands with primary hypercholesterolemia manifesting total cholesterol (TC) greater than 7.5mmol/L or LDL-C greater than 4.9mmol/L were selected from a lipid clinic in a public hospital in Hong Kong. After screening of 132 unrelated potential probands and their relatives, 252 subjects from 87 pedigrees were clinically diagnosed as heFH. RESULTS: In 252 heFH patients (mean age 37±17 years, 100 males), the plasma TC and LDL-C were 9.1±1.5mmol/L and 7.2±1.5mmol/L, respectively. In subjects aged ≥18years, the prevalence of xanthomata and corneal arcus was 40.6% and 81.2% in males, and 54.8% and 66.9% in females respectively. The overall incidence of CHD was 9.9% in males and 8.5% in females in patients aged over 18years with CHD history available. Multiple logistic regression analysis showed that advanced age and presence of xanthelasmata were significantly associated with increased risk of CHD. CONCLUSIONS: This study is the first to characterize the epidemiologic features of heFH in Hong Kong Chinese, which provides new population-specific information on this genetic disorder. This may presage how this condition will manifest in China in the near future.
    No preview · Article · Mar 2012 · International journal of cardiology
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    ABSTRACT: Although peritoneal dialysis (PD) is a widely accepted form of renal replacement therapy, concerns remain regarding the bioincompatible nature of standard PD fluid (PDF). Short-term studies of new biocompatible PDFs low in glucose degradation products (GDPs) reveal divergent results with respect to peritoneal integrity. We studied 125 patients on maintenance PD who were assigned, by simple randomization, to receive either conventional or low-GDP PDF at PD initiation. Parameters of dialysis adequacy and peritoneal transport of small solutes were determined at initiation and after a period of maintenance PD at the time when serum and overnight effluent dialysate were simultaneously collected and assayed for various cytokines, chemokines, adipokines, and cardiac biomarkers. All patients were further followed prospectively for an average of 15 months from the day of serum and effluent collection to determine patient survival and cardiovascular events. Patients treated with conventional or low-GDP PDF were matched for sex, age, duration of dialysis, dialysis adequacy, and incidence of cardiovascular disease or diabetes. After an average of 2.3 years of PD treatment, the weekly total and peritoneal creatinine clearance, and the total and peritoneal Kt/V were comparable in the groups. However, urine output was higher in patients using low-GDP PDF despite there having been no difference between the groups at PD initiation. Patients using low-GDP PDF also experienced a slower rate of decline of residual glomerular filtration and urine output than did patients on conventional PDF. Compared with serum concentrations, effluent concentrations of tumor necrosis factor α, hepatocyte growth factor, macrophage migration inhibitory factor, interleukins 8 and 6, C-reactive protein, and leptin were found to be higher in both groups of patients after long-term PD, suggesting that the peritoneal cavity was the major source of those mediators. Compared with patients on low-GDP PDF, patients on conventional fluid showed elevated leptin and reduced adiponectin levels in serum and effluent. The effluent concentration of interleukin 8 was significantly lower in patients using low-GDP PDF. The survival rate and incidence of cardiovascular complications did not differ between these groups after maintenance PD for an average of 3.6 years. It appears that low-GDP PDF results in an improvement of local peritoneal homeostasis through a reduction of chronic inflammatory status in the peritoneum.
    Full-text · Article · Nov 2011
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    Da P Chen · Chun K Wong · Lai S Tam · Edmund K Li · Christopher W K Lam
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    ABSTRACT: Hyperuricemia-mediated uric acid crystal formation may cause joint inflammation and provoke the destruction of joints through the activation of inflammasome-mediated innate immune responses. However, the immunopathological effects and underlying intracellular regulatory mechanisms of uric acid crystal-mediated activation of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA) have not been elucidated. Therefore, we investigated the in vitro effects of monosodium urate crystals, alone or in combination with the inflammatory cytokines tumor-necrosis factor (TNF)-α or interleukin (IL)-1β, on the activation of human FLS from RA patients and normal control subjects and the underlying intracellular signaling mechanisms of treatment with these crystals. Monosodium urate crystals were able to significantly increase the release of the inflammatory cytokine IL-6, the chemokine CXCL8 and the matrix metalloproteinase (MMP)-1 from both normal and RA-FLS (all P<0.05). Moreover, the additive or synergistic effect on the release of IL-6, CXCL8 and MMP-1 from both normal and RA-FLS was observed following the combined treatment with monosodium urate crystals and TNF-α or IL-1β. Further experiments showed that the release of the measured inflammatory cytokine, chemokine and MMP-1 stimulated by monosodium urate crystals were differentially regulated by the intracellular activation of extracellular signal-regulated kinase and c-Jun N-terminal kinase pathways but not the p38 mitogen-activated protein kinase pathway. Our results therefore provide a new insight into the uric acid crystal-activated immunopathological mechanisms mediated by distinct intracellular signal transduction pathways leading to joint inflammation in RA.
    Full-text · Article · Sep 2011 · Cellular & molecular immunology
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    ABSTRACT: Previous studies have suggested that Lingzhi (Ganoderma lucidum) has antioxidant effects and possibly beneficial effects on blood pressure, plasma lipids and glucose, but these have not been confirmed in subjects with mild hypertension or hyperlipidaemia. The objective of the present study was to assess the cardiovascular, metabolic, antioxidant and immunomodulatory responses to therapy with Lingzhi in patients with borderline elevations of blood pressure and/or cholesterol in a controlled cross-over trial. A total of twenty-six patients received 1·44 g Lingzhi daily or matching placebo for 12 weeks in a randomised, double-blind, cross-over study with placebo-controlled run-in and cross-over periods. Body weight, blood pressure, metabolic parameters, urine catecholamines and cortisol, antioxidant status and lymphocyte subsets were measured after each period. Lingzhi was well tolerated and data from twenty-three evaluable subjects showed no changes in BMI or blood pressure when treated with Lingzhi or placebo. Plasma insulin and homeostasis model assessment-insulin resistance were lower after treatment with Lingzhi than after placebo. TAG decreased and HDL-cholesterol increased with Lingzhi but not with placebo in the first treatment period, but significant carry-over effects prevented complete analysis of these parameters. Urine catecholamines and cortisol, plasma antioxidant status and blood lymphocyte subsets showed no significant differences across treatments. Results indicate that Lingzhi might have mild antidiabetic effects and potentially improve the dyslipidaemia of diabetes, as shown previously in some animal studies. Further studies are desirable in patients with hyperglycaemia.
    Preview · Article · Aug 2011 · The British journal of nutrition
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    ABSTRACT: Indoor aeroallergen exposures increased asthma symptoms in Caucasians, but their determinants and relationship to asthma and allergy in Asians are unclear. This study investigated exposures to cat, cockroach, and Blomia tropicalis allergens in 115 Hong Kong families with asthmatic children. Patients underwent exhaled nitric oxide and spirometric measurements. Home visits were made within 2 weeks during which parents completed a standardized questionnaire. Fel d 1, Bla g 2, and Blo t 5 in dust samples collected from patients' mattresses, bedroom floors, and living room floors were measured by immunoassays. These aeroallergens were only detectable in some homes (38-55% for Fel d 1; 9-21% for Bla g 2, and 7-14% for Blo t 5). The presence of cat and/or dog was a strong determinant for Fel d 1 in all indoor sites. The timing and frequency of bedding change was associated with Bla g 2 levels, whereas the timing of bedroom floor cleaning was a consistent factor for Blo t 5 levels. Asthmatic children in families with high allergen exposure were more likely to have ≥4 wheezing attacks in preceding 12 months and exercise-induced wheezing than those with normal allergen exposure (P = 0.051 and 0.030, respectively). Mattress levels of all three allergens were also associated with severity of several allergy symptoms (P = 0.025-0.005). None of these aeroallergens correlated with exhaled nitric oxide and spirometric parameters. This study identifies determinants for cat, cockroach, and B. tropicalis levels in Hong Kong families with asthmatic children. These exposures are associated with severity of allergy symptoms.
    Full-text · Article · Jul 2011 · Pediatric Pulmonology
  • Ruby H.Y. Yu · Suzanne C Ho · Christopher W.K. Lam · Jean L.F. Woo · Stella S.Y. Ho
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    ABSTRACT: Substantial evidence shows that C-reactive protein (CRP) is associated with atherosclerosis. However, data on the association between CRP and subclinical atherosclerosis are lacking in postmenopausal Chinese women. We aimed to describe the distribution of CRP and its association with metabolic syndrome (MS) and subclinical atherosclerosis in postmenopausal Chinese women in Hong Kong. Between 2002 and 2004, we recruited 518 postmenopausal women aged 50 to 64 years. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria. Subclinical atherosclerosis was determined by measuring carotid intima-media thickness (IMT) and plaque (focal wall thickening ≥1.5 mm) using high-resolution B-mode ultrasonography. Median CRP level was 1.00 mg/L. Women with MS had higher median CRP levels than those without MS (1.85 vs 0.80 mg/L, P < .05), and there was a modest trend toward increasing CRP levels with more metabolic components (P for trend < .05). Adjusted for age, hormonal use, and lifestyle factors, women with CRP levels of 0.5 to less than 1.0 mg/L had significantly higher mean IMT compared with those with CRP levels of less than 0.5 mg/L (0.78 vs 0.74 mm, P < .05). Odds ratio for plaque was 1.92 (95% confidence interval, 1.06-3.50) for women with CRP levels of 1.0 to less than 3.0 mg/L compared with those with CRP levels of less than 0.5 mg/L. Further adjustment for MS eliminated the associations. C-reactive protein did not add prognostic value to MS in the prediction of subclinical atherosclerosis. Compared with women without MS and who had CRP levels of less than 3.0 mg/L, those with CRP of at least 3.0 mg/L alone had similar IMT levels (0.75 vs 0.74 mm) and prevalence of plaque (19.4% vs 20.0%). Similarly, women with MS and who had CRP levels of at least 3.0 mg/L had similar IMT levels (0.81 vs 0.81 mm) and prevalence of plaque (30.1% vs 29.7%) compared with those with MS alone. C-reactive protein was strongly associated with MS and its individual components. However, it is not an independent predictor of subclinical atherosclerosis in postmenopausal Chinese women.
    No preview · Article · Nov 2010 · Metabolism: clinical and experimental
  • Ruby H.Y. Yu · Suzanne C Ho · Christopher W.K. Lam · Jean L.F. Woo · Stella S.Y. Ho
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    ABSTRACT: Substantial evidence shows that psychological factors are associated with cardiovascular diseases. However, data on the association between psychological factors and subclinical atherosclerosis is lacking in postmenopausal Chinese women. To examine the associations of perceived stress and trait anxiety with subclinical atherosclerosis in postmenopausal Chinese women in Hong Kong. Their relationships with biological and behavioral risk factors were also examined. Between 2002 and 2004, we recruited 518 postmenopausal women aged 50-64 years. Perceived stress and trait anxiety were evaluated by the perceived stress scale and the state-trait anxiety inventory, respectively. Subclinical atherosclerosis was determined by measuring carotid intima-media thickness (IMT) and plaque using B-mode ultrasonography. Perceived stress and trait anxiety showed no significant association with IMT or plaque. Multivariate analyses showed high perceived stress scores were associated with an increased risk of elevated total cholesterol (OR=2.10; 95% CI=1.17-3.77) and elevated low-density lipoprotein cholesterol (LDL-C) (OR=2.39; 95% CI=1.36-4.21). High trait anxiety scores were associated with a 2.7-fold risk of elevated LDL-C (OR=2.74; 95% CI=1.56-4.80). Women with high perceived stress or trait anxiety scores were more likely to be physically inactive. Perceived stress and trait anxiety were associated with atherogenic lipid levels, but not subclinical atherosclerosis. Maintaining high physical activity may help alleviate psychological stress and anxiety.
    No preview · Article · Oct 2010 · Maturitas
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    ABSTRACT: SUMMARY: Positional cloning and candidate gene studies in different Caucasian populations identified the gene encoding plant homeodomain zinc finger protein 11 (PHF11) to be associated with asthma and eczema. Microarray analysis also confirmed increased PHF11 expression in type 1 T-helper lymphocytes. However, such disease associations are unclear in Asian subjects. This case-control genetic association study investigated the relationship between asthma and eczema phenotypes and tagging single-nucleotide polymorphisms (SNPs) of PHF11 in Hong Kong Chinese children. Three hundred and nineteen asthmatic children and 236 children with eczema were recruited from hospital clinics and 445 children without any history of allergic disease were recruited as controls from local schools and hospitals. Atopy was defined by the presence of allergen-specific IgE in plasma or positive skin prick tests with wheal >or=3 mm larger than negative control. Lung function of asthmatics was evaluated by pre-bronchodilator spirometry. Ten PHF11 SNPs were genotyped by multiplex SNaPshot assay. Genotyping call rates were 100% for all SNPs, which also followed Hardy-Weinberg equilibrium. These SNPs were tightly linked in one haplotype block (D' >or= 0.95 for nearly all SNP pairs). Physician-diagnosed asthma was weakly associated with PHF11 +20860 and +22818 (P = 0.032 for both). Atopy was also associated with PHF11 +22398 (P = 0.029). However, none of the PHF11 SNPs was associated with eczema diagnosis and plasma total IgE and spirometric parameters in our patients. Our findings do not support PHF11 to be a major candidate gene for asthma, eczema and aeroallergen sensitization in Chinese children.
    No preview · Article · Sep 2010 · Pediatric Pulmonology
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    Chun K Wong · Da P Chen · Lai S Tam · Edmund K Li · Yi B Yin · Christopher W K Lam
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    ABSTRACT: Interleukin (IL)-27 is a novel member of the IL-6/IL-12 family cytokines that are produced early by antigen-presenting cells in T helper (Th)1-mediated inflammation. Elevated expression of IL-27 has been detected in the synovial membranes and fluid of rheumatoid arthritis (RA). We investigated the in vitro effects of IL-27, alone or in combination with inflammatory cytokine tumor necrosis factor (TNF)-α or IL-1 β on the pro-inflammatory activation of human primary fibroblast-like synoviocytes (FLS) from RA patients and normal control subjects, and the underlying intracellular signaling molecules were determined by intracellular staining using flow cytometry. Significantly higher plasma concentration of IL-27 was found in RA patients (n = 112) than control subjects (n = 46). Both control and RA-FLS constitutively express functional IL-27 receptor heterodimer, gp130 and WSX-1, with more potent IL-27-mediated activation of signal transducers and activators of transcription (STAT)1 in RA-FLS. IL-27 was found to induce significantly higher cell surface expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 and release of inflammatory chemokine IL-6, CCL2, CXCL9, CXCL10 and matrix metalloproteinase-1 of RA-FLS than that of control FLS (all P < 0.05). Moreover, an additive or synergistic effect was observed in the combined treatment of IL-27 and TNF-α or IL-1 β on the surface expression of ICAM-1 and VCAM-1 and the release of CXCL9 and CXCL10 of RA-FLS. Further investigations showed that the expression of ICAM-1, VCAM-1 and chemokines stimulated by IL-27 was differentially regulated by intracellular activation of phosphatidylinositol 3-OH kinase-AKT, c-Jun amino-terminal kinase and Janus kinase pathways. Our results therefore provide a new insight into the IL-27-activated immunopathological mechanisms mediated by distinct intracellular signal transductions in joint inflammation of RA.
    Full-text · Article · Jul 2010 · Arthritis research & therapy
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    ABSTRACT: Childhood and adolescence are critical periods of habit formation with substantial tracking of lifestyle and cardiovascular risk into adulthood. There are various guidelines on recommended levels of physical activity in youth of school-age. Despite the epidemic of obesity and diabetes in China, there is a paucity of data in this regard in Chinese youth. We examined the association of self-reported level of physical activity and cardiovascular risk in Hong Kong Chinese youth of school-age. This was a cross-sectional study conducted in 2007-8 in a school setting with 2119 Hong Kong Chinese youth aged 6-20 years. Physical activity level was assessed using a validated questionnaire, CUHK-PARCY (The Chinese University of Hong Kong: Physical Activity Rating for Children and Youth). A summary risk score comprising of waist circumference, blood pressure, fasting plasma glucose and lipids was constructed to quantify cardiovascular risk. In this cohort, 21.5% reported high level of physical activity with boys being more active than girls (32.1% versus 14.1%, p < 0.001). Regression analysis showed physical activity level, sex and pubertal stage were independently associated with cardiovascular risk score. Self-reported level of physical activity is associated with cardiovascular risk factors in Chinese youth after adjusting for sex and pubertal stage.
    Full-text · Article · Jun 2010 · BMC Public Health
  • Ju Cao · Chun K Wong · Yibing Yin · Christopher W.K. Lam
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    ABSTRACT: Interleukin (IL)-27 is a member of IL-6/IL-12 family cytokines produced by antigen-presenting cells in immune responses. IL-27 can drive the commitment of naive T cells to a T helper type 1 (Th1) phenotype and inhibit inflammation in later phases of infection. Human bronchial epithelial cells have been shown to express IL-27 receptor complex. In this study, we investigated the in vitro effects of IL-27, alone or in combination with inflammatory cytokine tumor necrosis factor (TNF)-alpha on the pro-inflammatory activation of human primary bronchial epithelial cells and the underlying intracellular signaling mechanisms. IL-27 was found to enhance intercellular adhesion molecule 1 (ICAM-1) expression on the surface of human bronchial epithelial cells, and a synergistic effect was observed in the combined treatment of IL-27 and TNF-alpha on the expression of ICAM-1. Although IL-27 did not alter the basal IL-6 secretion from bronchial epithelial cells, it could significantly augment TNF-alpha-induced IL-6 release. These synergistic effects on the up-regulation of ICAM-1 and IL-6 were partially due to the elevated expression of TNF-alpha receptor (p55TNFR) induced by IL-27. Further investigations showed that the elevation of ICAM-1 and IL-6 in human bronchial epithelial cells stimulated by IL-27 and TNF-alpha was differentially regulated by phosphatidylinositol 3-OH kinase (PI3K)-Akt, p38 mitogen-activated protein kinase, and nuclear factor-kappaB pathways. Our results therefore provide a new insight into the molecular mechanisms involved in airway inflammation.
    No preview · Article · Jun 2010 · Journal of Cellular Physiology
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    ABSTRACT: Domestic endotoxin enhances airway inflammation and increases asthma severity in Caucasian children, but little data are published on indoor endotoxin exposure in Asian countries. This study investigated house dust endotoxin and Der p 1 levels in Hong Kong families with asthmatic children, and their effects on asthma severity. 115 asthmatics from a pediatric clinic underwent fractional exhaled nitric oxide (FeNO) and spirometric measurements. Home visits were then made within 2 weeks, during which parents completed the International Study of Asthma and Allergies in Childhood questionnaire. Settled dust was collected from patients' mattresses, bedroom floors and living room floors. Endotoxin and Der p 1 were measured by limulus amebocyte lysate and immunoassay, respectively. Endotoxin was detectable in all locations from all families, whereas Der p 1 was detectable in 58-70% of indoor sites. Floors of both bedroom and living rooms had higher endotoxin but lower Der p 1 levels than mattresses (p < 0.001 for both). Mattress endotoxin level correlated inversely with Der p 1 level (r = -0.308, p = 0.001). Household smoker, feather bedding and vacuum cleaning were independent determinants of indoor endotoxin. Timing of last bedding change was associated with Der p 1 levels at all sites. Mattress endotoxin level was associated with frequency of wheezing episodes (p = 0.044), but neither endotoxin nor Der p 1 was associated with FeNO and spirometric parameters. Domestic endotoxin levels are associated with frequency of wheezing episodes in asthmatic children but not their FeNO or spirometric measurements.
    No preview · Article · Feb 2010 · International Archives of Allergy and Immunology
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    Joyce Y S Chow · Chun K Wong · Phyllis F Y Cheung · Christopher W K Lam
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    ABSTRACT: The novel interleukin (IL)-1 family cytokine IL-33 has been shown to activate T helper 2 (Th2) lymphocytes, mast cells and basophils to produce an array of proinflammatory cytokines, as well as to mediate blood eosinophilia, IgE secretion and hypertrophy of airway epithelium in mice. In the present study, we characterized the activation of human eosinophils by IL-33, and investigated the underlying intracellular signaling mechanisms. IL-33 markedly enhanced eosinophil survival and upregulated cell surface expression of the adhesion molecule intercellular adhesion molecule (ICAM)-1 on eosinophils, but it suppressed that of ICAM-3 and L-selectin. In addition, IL-33 mediates significant release of the proinflammatory cytokine IL-6 and the chemokines CXCL8 and CCL2. We found that IL-33-mediated enhancement of survival, induction of adhesion molecules, and release of cytokines and chemokines were differentially regulated by activation of the nuclear factor (NF)-kappaB, p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK) pathways. Furthermore, we compared the above IL-33 activities with two structurally and functionally related cytokines, IL-1beta and IL-18. IL-1beta, but not IL-18, markedly upregulated cell surface expression of ICAM-1. IL-1beta and IL-18 also significantly enhanced eosinophil survival, and induced the release of IL-6 and chemokines CXCL8 and CCL2 via the activation of the NF-kappaB, p38 MAPK and ERK pathways. Synergistic effects on the release of IL-6 were also observed in combined treatment with IL-1beta, IL-18 and IL-33. Taken together, our findings provide insight into IL-33-mediated activation of eosinophils via differential intracellular signaling cascades in the immunopathogenesis of allergic inflammation.
    Full-text · Article · Dec 2009 · Cellular & molecular immunology
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    ABSTRACT: The objective of this study was to evaluate circulating adipokines concentration in children with and without obstructive sleep apnea (OSA) and to determine the effects of treatment of OSA on their plasma concentration. Children with habitual snoring and symptoms suggestive of OSA were consecutively recruited. Their parents completed a sleep apnea symptom questionnaire, and the subjects underwent physical examination and an overnight polysomnography (PSG). OSA was diagnosed if they had an obstructive apnea index > 1. Fasting serum adiponectin, leptin, and lipid profiles were taken after overnight PSG. The subjects were divided into groups as obese, nonobese, and with and without OSA for comparison. One hundred forty-one children, of whom 96 were boys, with a median (interquartile range) age of 10.8 (8.5-12.8) years were recruited. Forty-three subjects had OSA. Subjects with OSA did not have significantly different adiponectin and leptin concentrations than those without OSA for both the obese and nonobese groups. Stepwise multiple linear regressions revealed that systolic BP, age, high-density lipoprotein cholesterol, and BMI z-score were independently associated with adiponectin, whereas diastolic BP, triglyceride, height, and BMI z-score were independently associated with leptin concentration. Sixteen children with OSA underwent treatment, and there was reduction in their plasma adiponectin concentration after intervention, but such change became insignificant after controlling for change in the BMI z-score. BMI rather than OSA was the main determinant of adipokines in children.
    No preview · Article · Dec 2009 · Chest

Publication Stats

4k Citations
638.30 Total Impact Points


  • 2010-2013
    • Macau University of Science and Technology
      Macao, Macau, Macao
  • 1987-2013
    • The Chinese University of Hong Kong
      • • Department of Chemical Pathology
      • • Prince of Wales Hospital
      • • Department of Obstetrics and Gynaecology
      Hong Kong, Hong Kong
  • 1994-2009
    • Prince of Wales Hospital, Hong Kong
      Chiu-lung, Kowloon City, Hong Kong
  • 1991-2004
    • Royal Prince Alfred Hospital
      • Department of Medical Oncology
      Camperdown, New South Wales, Australia
  • 1998
    • Queen Mary Hospital
      Hong Kong, Hong Kong
  • 1997
    • The University of Hong Kong
      Hong Kong, Hong Kong