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Featured researches published by Chi Man Koon.


Journal of Ethnopharmacology | 2010

In vitro & in vivo assessment of a herbal formula used topically for bone fracture treatment

Li Hua Peng; Chun-Hay Ko; Sum Wing Siu; Chi Man Koon; Gar Lee Yue; Wai Hing Cheng; T.W. Lau; Quan Bin Han; Ka Ming Ng; Kwok-Pui Fung; Clara Bik-San Lau; Ping Chung Leung

AIM OF THE STUDY A novel topical paste used for fracture healing (FH), consisting of the extracts of six herbs, Radix Dipsaci, Ramulus Sambucus Williamsii, Rhizoma Notoginseng, Flos Carthami, Rhizoma Rhei and Fructus Gardeniae, was developed according to the classical theory of traditional Chinese medicine. This study aimed to determine the effectiveness of this formula, and some of its important chemical components in the promotion of fracture healing. The transdermal transport of FH was also examined. MATERIALS AND METHODS The osteogenic, angiogenic and nitric oxide suppressing effects of FH and its important chemical marker components were assessed by using osteoblastosacroma UMR-106 cells, human umbilical vein endothelial cells (HUVEC) and murine macrophage RAW264.7 cells, respectively. The bone healing effects of the FH paste and its transdermal absorption were determined using a rabbit fracture model. The callus sizes, bone specific alkaline phosphatase levels and biomechanical properties of the healed bone were assessed. RESULTS FH significantly increased the cell proliferation in UMR-106 and HUVEC cells and inhibited the nitric oxide production in murine macrophage in dose-dependent manner. Its important chemical components asperosaponin VI, ginsenoside Rg1 and emodin were shown to be acting positively in the respective in vitro studies. FH paste significantly improved the bone healing in the rabbit fracture model, as was indicated by the increases in callus size at weeks 2-5, and the elevations in bone specific alkaline phosphatase activities at weeks 5-6. The analysis using LC/MS/MS also showed the presence of important chemical marker components of the FH formula in the plasma after 8 weeks of topical treatment. CONCLUSION This study presents the first scientific evidence of the efficacy of a herbal paste in the promotion of fracture healing. There were evidences of transdermal transport of the chemical components, control the inflammation through nitric oxide inhibition, promotion of angiogenesis, and bone healing in the in vitro tests, as well as in the experimental animal.


Journal of Ethnopharmacology | 2011

Bioassay-guided isolation of norviburtinal from the root of Rehmannia glutinosa, exhibited angiogenesis effect in zebrafish embryo model

Cheuk Lun Liu; Ling Cheng; Hin Fai Kwok; Chun-Hay Ko; T.W. Lau; Chi Man Koon; Ming Zhao; Ching Po Lau; Kit Man Lau; Chun Wai Wong; Ping Chung Leung; Kwok-Pui Fung; Clara Bik-San Lau

ETHNOPHARMACOLOGICAL RELEVANCE The root of Rehmannia glutinosa (RR) is commonly used as a wound-healing agent in various traditional Chinese herbal formulae; while angiogenesis is one of the crucial aspects in wound-healing. AIM OF THE STUDY The objective of the present study was to investigate the angiogenesis effects of RR aqueous crude extract and its active component(s) using zebrafish model. MATERIALS AND METHODS The in vivo angiogenesis effect was studied using transgenic TG(fli1:EGFP)(y1)/+(AB) zebrafish embryos by observing the capillary sprouts formation in sub-intestinal vessel (SIV) of zebrafish embryos after 72 h post-fertilization under fluorescence microscopy. RESULTS Our results indicated that RR aqueous crude extract (250 μg/ml) exhibited significant angiogenesis effect, with an increase in capillary sprouts formation in SIV. Following sequential solvent partition of the RR aqueous crude extract with dichloromethane, ethyl acetate and n-butanol successively, the dichloromethane fraction (DCM) was found to have the most sprouts formation in the SIV region. Subjected to column chromatography, DCM fraction was further fractionated into six sub-fractions and among these tested, the sub-fraction C2 exhibited the most potent angiogenesis effect. The major component, C2A, was isolated and identified as norviburtinal using nuclear magnetic resonance (NMR) and mass spectrometry (MS). The compound norviburtinal (at 50 μg/ml) was shown to possess significant angiogenesis effect in zebrafish model (p < 0.001). CONCLUSIONS Norviburtinal was, for the first time, found in the extract of RR and possessed novel angiogenesis effect. Bioassay-guided fractionation suggested that norviburtinal was not the only active component responsible for the angiogenesis effect of RR.


Journal of Ethnopharmacology | 2011

Transcriptional profiling of human skin fibroblast cell line Hs27 induced by herbal formula Astragali Radix and Rehmanniae Radix.

Qi Zhang; Fan Wei; Chi Chun Fong; Wai Kin Yu; Yao Chen; Chi Man Koon; Kit Man Lau; Ping Chung Leung; Clara Bik-San Lau; Kwok-Pui Fung; Mengsu Yang

ETHNOPHARMACOLOGICAL RELEVANCE The herbs Astragali Radix (AR) and Rehmanniae Radix (RR) have long been used in traditional Chinese Medicine and serve as the principal herbs in treating diabetic foot ulcer. AIM OF THE STUDY Chinese herbal formulus comprising Astragali Radix (AR) and Rehmanniae Radix (RR) have been shown to improve the healing of diabetic foot ulcer through enhancing the viability of primary fibroblasts in diabetic patients suffering insulin resistance. Our previous study demonstrated that the herbal formula NF3 comprising of AR and RR in the ratio of 2:1 was effective in promoting wound healing in diabetic rats, and in vitro data indicated that the wound healing effects of NF3 might be due to the regulation and coordination of inflammation, angiogenesis and tissue regeneration. However, the underlying molecular mechanism has not been well investigated. In this study, we investigated the cellular and molecular effects of the herbal formula NF3 on human skin fibroblast cells. MATERIALS AND METHODS Human skin fibroblast cells Hs27 were treated with NF3 ranging from 0 to 8 mg/ml for 24h, and the cells without NF3 treatment were used as control. Cell proliferation assay and cell cycle analysis were performed. Transcriptional profiles of Hs27 cells upon NF3 treatment were acquired by using a human cDNA microarray containing 10,000 genes, and the signaling pathways differentially regulated by NF3 were identified and analyzed. RESULTS NF3 promoted Hs27 cell proliferation and cell cycle progression. Microarray analysis revealed that 116 genes were differentially expressed upon NF3 treatment. Functional analysis of the genes indicated that NF3 mainly activated Wnt and angiogenesis related pathways, which are directly related to cell proliferation, angiogenesis, extracellular matrix (ECM) formation and inflammation during the process of wound healing. CONCLUSION This study provides insight into the molecular mechanism of how the herbal formula Astragali Radix and Rehmanniae Radix may serve as potential therapeutics for wound healing.


Journal of Ethnopharmacology | 2011

Danshen-Gegen decoction exerts proliferative effect on rat cardiac myoblasts H9c2 via MAPK and insulin pathways.

Chi Chun Fong; Fan Wei; Yao Chen; Wai Kin Yu; Chi Man Koon; Ping Chung Leung; Kwok-Pui Fung; Clara Bik-San Lau; Mengsu Yang

ETHNOPHARMACOLOGICAL RELEVANCE Danshen (root of Salvia miltiorrhiza) and Gegen (roots of Pueraria lobata) are traditional Chinese medicines that have been used in combination for cardiovascular disease treatment. AIM OF THE STUDY The present study was performed to investigate the effect of Danshen-Gegen decoction on rat myocardium cell line H9c2 and the possible molecular mechanisms. MATERIALS AND METHODS Rat heart myocardium H9c2 cells were treated with or without Danshen-Gegen decoction (DG) ranging from 10 to 1000μg/ml for 24h. Cell viability was measured by Alarma blue assay and cell proliferation assay was performed by BrdU Cell Proliferation ELISA kit. The activation of mitogen-activated protein kinase and insulin pathways was analyzed by Luminex technology and the growth factors and cytokine expression of H9c2 cells induced by DG was evaluated by protein array. Moreover, a rat functional specific cDNA microarray was constructed to study the gene expression profiles of H9c2 cells upon the DG treatment at 50μg/ml for 24h. RESULTS DG promoted H9c2 cell viability and cell proliferation at dose-dependent manner within the range between 0 and 250μg/ml. A Bio-Plex assay kit (Bio-Rad Bioscience) was used to detect the expression level of phosphoprotein as well as total proteins involved in the MAPK and insulin pathways. Significant phosphorylation of ERK, c-Jun, JNK, p38, AKT, IGF-IR, IRS-1and I kappa B were observed after DG treatment at 2h or 4h. A rat cytokine antibody array was used to detect and quantify 22 growth factors and cytokines in samples collected from the control and DG treated H9c2 cells. In the category of growth factors, GM-CSF, CNIF and b-NGF were stimulated by DG, while the expression of TIMP-1 was suppressed. For cytokine expression, it was found that DG stimulated three interleukin subclasses, IL-1α, 1X and 6, respectively. However, the expression of pro-inflammatory factors such as TNF-α and IFN-γ were down-regulated significantly. Moreover, the microarray analysis revealed that DG significantly up-regulated anti-apoptosis related genes such as Cdkn2c and Ppp3ca, and several cardiovascular disease suppressers and anti-inflammatory mediators; on the other hand, pro-apoptotic related genes including Caspase and Tnf-α were down-regulated by DG. Based on the results, a tentative scheme was proposed to show that the activation of the MAPK and insulin pathways are involved in the bioactive effect of Danshen-Gegen decoction on cardiomyocytes. CONCLUSION Our study suggested that Danshen-Gegen decoction has proliferative effect on myocardium cells via MAPK and insulin signaling pathways. The molecular mechanism of the action may include the up-regulation of IRS/AKT and JNK pathways as well as the inhibition of TNF and p38 pathways.


Phytomedicine | 2012

Herbal formula Astragali Radix and Rehmanniae Radix exerted wound healing effect on human skin fibroblast cell line Hs27 via the activation of transformation growth factor (TGF-β) pathway and promoting extracellular matrix (ECM) deposition

Qi Zhang; Chi Chun Fong; Wai Kin Yu; Yao Chen; Fan Wei; Chi Man Koon; Kit Man Lau; Ping Chung Leung; Clara Bik-San Lau; Kwok-Pui Fung; Mengsu Yang

Astragali Radix (AR) and Rehmanniae Radix (RR) have long been used in traditional Chinese Medicine and as the principal herbs in treating diabetic foot ulcer. In this study, we investigated the effect of NF3, which comprises of AR and RR in the ratio of 2:1(w/w), on skin fibroblast cell migration and the activation of selected genes and proteins related to wound healing. Human skin fibroblast cell line Hs27 was treated with NF3 at 4 mg/ml for 24h, and in vitro scratch wound healing and quantitative cell migration assays were performed, respectively. The expression of transformation growth factor (TGF-β1) and bone morphogenetic protein 6 (BMP6) in Hs27 cells with or without NF3 treatment was analyzed by western blot analysis. In addition, the expression of a panel of genes involved in human TGF-β signaling pathway was analyzed in Hs27 cells upon NF3 treatment (4 mg/ml, 24 h) by quantitative real-time PCR (qRT-PCR). Furthermore, the expression of several genes and proteins associated with ECM synthesis was investigated by qRT-PCR analysis or/and ELISA techniques. The results suggested that NF3 promoted the migration of human skin fibroblast cells. Western blot analysis demonstrated that NF3 up-regulated TGF-β1 and BMP-6 synthesis. qRT-PCR analysis revealed that the expression of 26 genes in Hs27 cells was changed upon NF3 induction, including TGF-β superfamily ligands and down stream effectors genes, and genes involved in TGF/Smad pathway, and Ras/MAPK (non-Smad) pathway. Among the extracellular matrix (ECM)-related molecules, it was found that NF3 up-regulated the expression of type I and III collagens, fibronectin as well as TIMP-1, and down-regulated the MMP-9 expression in skin fibroblast cells. This study demonstrated that herb formula NF3 could enhance skin fibroblast cell migration and activated genes involved in TGF-β1 pathway. NF3 could regulate gene transcription for extracellular matrix synthesis via the Smad pathway, and gene transcription for cell motility via the Ras/MAPK (non-Smad) pathway.


Evidence-based Complementary and Alternative Medicine | 2013

Effect of Dietary Cocoa Tea (Camellia ptilophylla) Supplementation on High-Fat Diet-Induced Obesity, Hepatic Steatosis, and Hyperlipidemia in Mice

Xiao rong Yang; Elaine Wat; Yan Ping Wang; Chun-Hay Ko; Chi Man Koon; Wing Sum Siu; Si Gao; David Wing-Shing Cheung; Clara Bik-San Lau; Chuang Xing Ye; Ping Chung Leung

Recent studies suggested that green tea has the potential to protect against diet-induced obesity. The presence of caffeine within green tea has caused limitations. Cocoa tea (Camellia ptilophylla) is a naturally decaffeinated tea plant. To determine whether cocoa tea supplementation results in an improvement in high-fat diet-induced obesity, hyperlipidemia and hepatic steatosis, and whether such effects would be comparable to those of green tea extract, we studied six groups (n = 10) of C57BL/6 mice that were fed with (1) normal chow (N); (2) high-fat diet (21% butterfat + 0.15% cholesterol, wt/wt) (HF); (3) a high-fat diet supplemented with 2% green tea extract (HFLG); (4) a high-fat diet supplemented with 4% green tea extract (HFHG); (5) a high-fat diet supplemented with 2% cocoa tea extract (HFLC); and (6) a high-fat diet supplemented with 4% cocoa tea extract (HFHC). From the results, 2% and 4% dietary cocoa tea supplementation caused a dose-dependent decrease in (a) body weight, (b) fat pad mass, (c) liver weight, (d) total liver lipid, (e) liver triglyceride and cholesterol, and (f) plasma lipids (triglyceride and cholesterol). These data indicate that dietary cocoa tea, being naturally decaffeinated, has a beneficial effect on high-fat diet-induced obesity, hepatomegaly, hepatic steatosis, and elevated plasma lipid levels in mice, which are comparable to green tea. The present findings have provided the proof of concept that dietary cocoa tea might be of therapeutic value and could therefore provide a safer and cost effective option for patients with diet-induced metabolic syndrome.


Journal of Ethnopharmacology | 2016

The aqueous extract of rhizome of Gastrodia elata Blume attenuates locomotor defect and inflammation after traumatic brain injury in rats.

Chun Fai Ng; Chun-Hay Ko; Chi Man Koon; Wai Ching Chin; Hiu Ching Sonya Themis Kwong; Anthony W.I. Lo; Hing Lok Wong; Kwok-Pui Fung; Clara Bik-San Lau; Ping Kuen Lam; Wai Sang Poon; Ping Chung Leung

ETHNOPHARMACOLOGICAL RELEVANCE Traumatic brain injury (TBI) has an incident rate of 200-300 people per 100,000 annually in the developed countries. TBI has relatively high incidence at an early age and may cause long-term physical disability. Patients suffered from severe TBI would have motor and neuropsychological malfunctions, affecting their daily activities. Traditionally, Gastrodia elata Blume is a Chinese Medicines which was used for the head diseases, while their efficiency on reducing brain damage was still largely unknown. In the present study, we aimed to examine the effect of water extract of G. elata Blume (GE) against TBI and elucidate its underlying mechanism. MATERIALS AND METHODS Sprague-Dawley rats were treated with GE for 7 days, immediately after controlled cortical impact-induced TBI. Impaired neurobehavioral functioning was measured on day 3 and 6 after TBI. Histology of TBI was examined to assess the extent of inflammation, and the expressions of pro-inflammatory cytokines were examined by immunofluorescence study on day 7. RESULTS GE treatment significantly improved the impaired locomotor functions induced by TBI. GE treatment reduced inflammation and gliosis in the penumbral area. The increase in brain levels of pro-inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha observed in non-GE treated TBI rats were also reversed. CONCLUSIONS GE treatment attenuated the locomotor deficit caused by TBI. The anti-inflammatory activity might be mediated by inhibition of pro-inflammatory cytokines responses in the TBI-brain.


Phytomedicine | 2012

Involvements of calcium channel and potassium channel in Danshen and Gegen decoction induced vasodilation in porcine coronary LAD artery.

Fan Hu; Chi Man Koon; Judy Yuet-Wa Chan; Kit Man Lau; Yiu Wa Kwan; Kwok-Pui Fung

Danshen (Salviae Miltiorrhizae Radix) and Gegen (Puerariae Lobatae Radix) have been widely used in treating cardiovascular diseases for thousands of years in China. The present study was carried out to evaluate the effects of a Danshen and Gegen decoction (DG) on the vascular reactivity of a porcine isolated coronary artery and the underlying mechanisms involved. Porcine coronary rings were precontracted with 15 nM U46619. The involvement of endothelium-dependent mechanisms was explored by removing the endothelium; the involvement of potassium channels was investigated by the pretreatment of the artery rings with various blockers, and the involvement of the calcium channels was investigated by incubating the artery rings with Ca²⁺-free buffer and priming them with high [K⁺] prior to adding CaCl₂ to elicit contraction. The involvement of Ca²⁺ sensitization was explored by evaluating the Rho-activity expression. The results revealed that DG elicited a concentration-dependent relaxation on a U46619-precontracted coronary artery ring. These relaxation responses were not altered by the pretreatment of inhibitors of endothelium-related dilator synthases, cGMP and cAMP pathway inhibitors, potassium channel (BK(Ca), SK(Ca), K(V) and K(ATP)) blockers and endothelium removal. The K(IR) channel blocker BaCl₂ only slightly attenuated the DG-induced relaxation. However, the Ca²⁺-induced artery contraction was inhibited by DG. Additionally, the expression of the phosphorylated myosin light chain was inhibited by DG whereas the activity of RhoA was not affected. Therefore, DG could be a useful cardioprotective agent for vasodilation in patients who have hypertension.


Journal of Ethnopharmacology | 2016

The hepatoprotective effect of the combination use of Fructus Schisandrae with statin--A preclinical evaluation.

Elaine Wat; Chun Fai Ng; Eric Chun-Wai Wong; Chi Man Koon; Ching Po Lau; David Wing-Shing Cheung; Kwok-Pui Fung; Clara Bik-San Lau; Ping Chung Leung

ETHNOPHARMACOLOGICAL RELEVANCE Fructus Schisandrae is traditionally used as a liver-toning Chinese herb. Recent studies suggested Fructus Schisandrae could prevent high-fat diet-induced hepatic steatosis as well as improving anti-oxidative status within the liver, which is a proposed mechanism against statin-induced liver toxicity. AIM The aim of the present study was to determine if the combination use of Atorvastatin (AS) and Fructus Schisandrae aqueous extract (FSE) could (a) exert potent therapeutic effects not only on high-fat diet-induced hyperlipidemia, but also on hepatomegaly (enlarge of liver size) and hepatic steatosis (fatty liver); and (b) reduce side effects caused by intake of statin alone including increased incidence of elevated liver enzymes and liver toxicity in Sprague Dawley rats. MATERIALS AND METHODS We studied 5 groups of Sprague Dawley rats that were given the following treatment for 8 weeks: (i) Normal-chow diet; (ii) High-fat diet (contains 21% fat and 0.15% cholesterol); (iii) High-fat diet (contains 21% fat and 0.15% cholesterol)+0.3% Atorvastatin; (iv) High-fat diet (contains 21% fat and 0.15% cholesterol)+0.45% FSE; (v) High-fat diet (contains 21% fat and 0.15% cholesterol)+0.3% Atorvastatin+0.45% FSE. After 8 weeks of treatment, body weight, adipose tissue and liver mass were measured, and liver and plasma lipid levels were determined to evaluate to effect of FSE with or without AS treatment on diet-induced obesity, hyperlipidemia and hepatic steatosis. Liver enzyme activities, anti-oxidative status and membrane permeability transition were also assessed to determine if FSE could reduce the side effects induced by AS. RESULTS From the results, FSE treatment alone resulted in significant inhibitory effect on diet-induced increase in: (a) body weight; (b) fat pad mass (epididymal, perirenal and inguinal fat); (c) liver weight; (d) total liver lipid; (e) liver triglyceride and cholesterol levels; and (f) plasma lipid levels, suggesting FSE has a potential preventive beneficial effect on weight control and lipid metabolism in Sprague Dawley rats with diet-induced obesity. However, FSE supplementation exerted no further beneficial effect on diet-induced metabolic syndrome when it is combined with AS treatment, compared with rats given AS-treatment alone. At the dose of 0.45%, dietary FSE supplementation resulted in: (a) reduced liver enzymes (ALT and AST) levels; (b) reduced macrophage infiltration (CD68); (c) improved liver glutathione levels (anti-oxidative status); (d) reduced liver reactive oxidative species; (e) a trend to reduce calcium-induced membrane permeability transition within the liver. Most importantly, these improvements induced by FSE treatment were not only observed in the livers of rats given high-fat-diet, but also in high-fat-fed rats with atorvastatin-induced hepatotoxicity. CONCLUSIONS Taken together, these data suggested FSE has a potential beneficial effect on weight control and lipid metabolism in Sprague Dawley rats with diet-induced obesity, and the combination use of FSE with AS could significantly prevent liver toxicity and anti-oxidative status induced by AS alone.


Journal of Ethnopharmacology | 2016

The protective effect of Herba Cistanches on statin-induced myotoxicity in vitro.

Elaine Wat; Chun Fai Ng; Chi Man Koon; Eric Chun-Wai Wong; Brian Tomlinson; Clara Bik-San Lau

ETHNOPHARMACOLOGICAL RELEVANCE Herba Cistanches (HC, Cistanche deserticola or Cistanche tubulosa) is a Chinese herb traditionally used for muscle problems. Previous studies demonstrated that HC extract could reduce muscle damage and improve ATP storage in post-exercised rats. However, its effect on statin-induced muscle toxicity has never been investigated. AIM The objective of this study was to determine if the aqueous extract of HC (HCE) could prevent simvastatin-induced toxicity in L6 rat skeletal muscle cells; and whether verbascoside is the major bioactive constituent which contributes to the effects. MATERIALS AND METHODS MTT was performed to determine the effects of HCE (0-2000µg/ml) or verbascoside (0-160µM) on simvastatin (10µM)-treated L6 cells. Annexin V-FITC/PI apoptosis assay and Caspase 3 assay were performed to determine the protective role of HCE on simvastatin-induced cell death, and to evaluate if HCE exerted its protective effect through the caspase pathway. ATP production was measured to investigate if HCE could prevent simvastatin-induced reduction in ATP production in vitro. RESULTS Simvastatin significantly increased apoptotic cell death in L6 cells. HCE significantly exerted a dose-dependent reduction on simvastatin-induced apoptotic cells, possibly via caspase-3 pathway. Simvastatin reduced the ATP production in L6 cells, which was dose-dependently prevented by HCE. There was only a trend but not significant effect (except at high dose) of verbascoside on the protection of simvastatin-induced muscle toxicity. CONCLUSIONS In conclusion, we demonstrated for the first time that HCE could exert dose-dependent protective effect on simvastatin-induced toxicity in vitro, which was unlikely due to the presence of verbascoside. Our study suggested the potential use of HC under the situation of simvastatin-induced muscle toxicity.

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Clara Bik-San Lau

The Chinese University of Hong Kong

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Ping Chung Leung

The Chinese University of Hong Kong

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Kwok-Pui Fung

The Chinese University of Hong Kong

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Chun-Hay Ko

The Chinese University of Hong Kong

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Elaine Wat

The Chinese University of Hong Kong

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Kit Man Lau

The Chinese University of Hong Kong

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Chi Chun Fong

City University of Hong Kong

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Chun Fai Ng

The Chinese University of Hong Kong

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David Wing-Shing Cheung

The Chinese University of Hong Kong

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Mengsu Yang

City University of Hong Kong

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