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1.  Long-Term Risk of Cardiovascular Disease among Type 2 Diabetic Patients with Asymptomatic Intracranial Atherosclerosis: A Prospective Cohort Study 
PLoS ONE  2014;9(9):e106623.
To investigate whether asymptomatic middle cerebral artery (MCA) stenosis is associated with risk of cardiovascular disease (CVD) in Chinese with type 2 diabetes.
In this prospective cohort study, 2,144 Hong Kong Chinese with type 2 diabetes and without history of stroke or atrial fibrillation were recruited in 1994–1996 and followed up for a median of 14.51 years. Participants were assessed at baseline for MCA stenosis using transcranial Doppler. We performed survival analysis to assess the association between asymptomatic MCA stenosis and first CVD event, defined as ischemic stroke, acute coronary syndrome (ACS) or cardiovascular death.
Of the 2,144 subjects, MCA stenosis at baseline was detected in 264 (12.3%). Rates of stroke, ACS and cardiovascular death per 100 were, respectively, 2.24, 2.92 and 1.11 among participants with stenosis, higher than among those without stenosis. Ten-year cumulative occurrence of stroke, ACS and cardiovascular death in subjects with MCA stenosis was 20%, 24% and 10%, respectively, higher than the corresponding values for subjects without stenosis(all P<0.001). After adjusting for covariates, MCA stenosis was found to be an independent predictor of stroke [hazard ratio (HR) 1.40, 95%CI 1.05–1.86; P = 0.02], ACS (HR 1.35, 95%CI 1.04–1.75; P = 0.02) and cardiovascular death(HR 1.56, 95%CI 1.04–2.33; P = 0.03).
Asymptomatic MCA stenosis is a risk factor for CVD in Chinese with type 2 diabetes, and detection of asymptomatic MCA stenosis by transcranial Doppler can identify diabetic individuals at high risk of future CVD. This finding is particularly important for diabetic individuals in Asia, where intracranial atherosclerosis is common.
PMCID: PMC4156359  PMID: 25192283
2.  Clinical Pharmacokinetics of Buffered Propranolol Sublingual Tablet (Promptol™)—Application of a New “Physiologically Based” Model to Assess Absorption and Disposition 
The AAPS Journal  2013;15(3):787-796.
Sublingual administration of certain buffered propranolol may improve the rate and extent of absorption compared to oral administration. The main objectives of this study were to (1) compare the plasma propranolol concentrations (Cp-prop) following sublingual administration of a specially buffered formulation (Promptol™) to that following oral administration of Inderal® and (2) evaluate the utility of a special pharmacokinetic model in describing the Cp-prop following sublingual administration. Eighteen healthy volunteers received 10 mg sublingual Promptol™ or oral Inderal®. Multiple Cp-prop were determined and their pharmacokinetics compared. Additional data following sublingual 40 mg Promptol™ or Inderal® were utilized for evaluation of a special advanced compartmental absorption and transit (ACAT) model. For model simulation, the physicochemical parameters were imported from AMET predictor, whereas the pharmacokinetic parameters were calculated and optimized by Gastroplus®. Based on this model, the quantity of drug absorbed via buccal/sublingual mucosa was estimated. Cp-prop was higher at earlier times with 3-fold greater relative bioavailability following sublingual Promptol™ compared to that from oral Inderal®. The special ACAT model provided excellent goodness of fit of Cp-prop-time curve and estimated a 56.6% increase in absorption rate from Promptol™ and higher initial Cp-prop compared to the regular formulation. The modified ACAT model provided a useful approach to describe sublingual absorption of propranolol and clearly demonstrated an improvement of absorption of Promptol™. The sublingual 10 mg Promptol™ achieved not only a similar systemic exposure as 30 mg oral Inderal® but an earlier effective Cp-prop which may be advantageous for certain clinical conditions.
PMCID: PMC3691420  PMID: 23605805
ACAT; buffered; pharmacokinetics; propranolol; sublingual
3.  Evaluation of a Crataegus-Based Multiherb Formula for Dyslipidemia: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial 
Background. We for the first time examined the effects of a multiherb formula containing Crataegus pinnatifida (1 g daily), Alisma orientalis, Stigma maydis, Ganoderma lucidum, Polygonum multiflorum, and Morus alba on plasma lipid and glucose levels in Chinese patients with dyslipidemia. Methods. In this randomized, double-blind, placebo-controlled study, 42 patients were randomized at a ratio of 1 : 1 to receive the herbal formula or placebo for 12 weeks and 40 patients completed the study. Lipid profiles, glucose, glycated haemoglobin (HbA1c), and laboratory safety parameters were performed before and after treatment. Results. The difference in the changes in low-density lipoprotein cholesterol (LDL-C) levels between placebo and active treatment (−9%) was significantly (P < 0.05) better with active treatment. HbA1c levels significantly decreased by −3.9% in the active treatment group, but the change was not significantly different from that with placebo (−1.1%) (P = 0.098). There were no apparent adverse effects or changes in laboratory safety parameters with either treatment. Conclusions. The multiherb formula had mild beneficial effects on plasma LDL-C after 12-weeks treatment in subjects with dyslipidemia without any noticeable adverse effects.
PMCID: PMC4009229  PMID: 24834096
4.  Bench to Bed Evidences for Pharmacokinetic and Pharmacodynamic Interactions Involving Oseltamivir and Chinese Medicine 
Oseltamivir (OA), an ethyl ester prodrug of oseltamivir carboxylate (OC), is clinically used as a potent and selective inhibitor of neuraminidase. Chinese medicines have been advocated to combine with conventional drug for avian influenza. The current study aims to investigate the potential pharmacokinetic and pharmacodynamic interactions of a Chinese medicine formula, namely, Yin Qiao San and Sang Ju Yin (CMF1), commonly used for anti-influenza in combination with OA in both rat and human, and to reveal the underlined mechanisms. It was found that although Cmax, AUC and urinary recovery of OC, as well as metabolic ratio (AUCOC/AUCOA), were significantly decreased in a dose-dependent manner following combination use of CMF1 and OA in rat studies (P < 0.01), such coadministration in 14 healthy volunteers only resulted in a trend of minor decrease in the related parameters. Further mechanistic studies found that although CMF1 could reduce absorption and metabolism of OA, it appears to enhance viral inhibition of OA (P < 0.01). In summary, although there was potential interaction between OA and CMF1 found in rat studies, its clinical impact was expected to be minimal. The coadministration of OA and CMF1 at the clinical recommended dosages is, therefore, considered to be safe.
PMCID: PMC3912631  PMID: 24527044
5.  Safety of statins: an update 
Statins are widely used and have been proven to be effective in the prevention of atherosclerotic vascular disease events, primarily by reducing plasma low-density lipoprotein cholesterol concentrations. Although statins are generally well tolerated and present an excellent safety profile, adverse effects from muscle toxicity and liver enzyme abnormalities may occur in some patients. Myopathy and rhabdomyolysis are rare with statin monotherapy at the approved dose ranges, but the risk increases with use of higher doses, interacting drugs and genetic predisposition. Asymptomatic increases in liver transaminases with statin treatment do not seem to be associated with an increased risk of liver disease. Therefore, statin treatment can be safely used in patients with mild to moderately abnormal liver tests that are potentially attributable to nonalcoholic fatty liver disease and can improve liver tests and reduce cardiovascular morbidity in this group of patients. The risks of other unfavorable effects such as the slightly increased risk of new-onset diabetes and potentially increased risk of haemorrhagic stroke are much smaller than the cardiovascular benefits with the use of statins.
PMCID: PMC4110822  PMID: 25083232
cardiovascular disease; drug safety; myopathy; rhabdomyolysis; statins
6.  Correction: A Genome-Wide Linkage and Association Scan Reveals Novel Loci for Hypertension and Blood Pressure Traits 
PLoS ONE  2012;7(6):10.1371/annotation/4415f88f-ab10-44dd-8ba9-1a57ade740c1.
PMCID: PMC3371059
7.  Identification of IGF1, SLC4A4, WWOX, and SFMBT1 as Hypertension Susceptibility Genes in Han Chinese with a Genome-Wide Gene-Based Association Study 
PLoS ONE  2012;7(3):e32907.
Hypertension is a complex disorder with high prevalence rates all over the world. We conducted the first genome-wide gene-based association scan for hypertension in a Han Chinese population. By analyzing genome-wide single-nucleotide-polymorphism data of 400 matched pairs of young-onset hypertensive patients and normotensive controls genotyped with the Illumina HumanHap550-Duo BeadChip, 100 susceptibility genes for hypertension were identified and also validated with permutation tests. Seventeen of the 100 genes exhibited differential allelic and expression distributions between patient and control groups. These genes provided a good molecular signature for classifying hypertensive patients and normotensive controls. Among the 17 genes, IGF1, SLC4A4, WWOX, and SFMBT1 were not only identified by our gene-based association scan and gene expression analysis but were also replicated by a gene-based association analysis of the Hong Kong Hypertension Study. Moreover, cis-acting expression quantitative trait loci associated with the differentially expressed genes were found and linked to hypertension. IGF1, which encodes insulin-like growth factor 1, is associated with cardiovascular disorders, metabolic syndrome, decreased body weight/size, and changes of insulin levels in mice. SLC4A4, which encodes the electrogenic sodium bicarbonate cotransporter 1, is associated with decreased body weight/size and abnormal ion homeostasis in mice. WWOX, which encodes the WW domain-containing protein, is related to hypoglycemia and hyperphosphatemia. SFMBT1, which encodes the scm-like with four MBT domains protein 1, is a novel hypertension gene. GRB14, TMEM56 and KIAA1797 exhibited highly significant differential allelic and expressed distributions between hypertensive patients and normotensive controls. GRB14 was also found relevant to blood pressure in a previous genetic association study in East Asian populations. TMEM56 and KIAA1797 may be specific to Taiwanese populations, because they were not validated by the two replication studies. Identification of these genes enriches the collection of hypertension susceptibility genes, thereby shedding light on the etiology of hypertension in Han Chinese populations.
PMCID: PMC3315540  PMID: 22479346
8.  A Genome-Wide Linkage and Association Scan Reveals Novel Loci for Hypertension and Blood Pressure Traits 
PLoS ONE  2012;7(2):e31489.
Hypertension is caused by the interaction of environmental and genetic factors. The condition which is very common, with about 18% of the adult Hong Kong Chinese population and over 50% of older individuals affected, is responsible for considerable morbidity and mortality. To identify genes influencing hypertension and blood pressure, we conducted a combined linkage and association study using over 500,000 single nucleotide polymorphisms (SNPs) genotyped in 328 individuals comprising 111 hypertensive probands and their siblings. Using a family-based association test, we found an association with SNPs on chromosome 5q31.1 (rs6596140; P<9×10−8) for hypertension. One candidate gene, PDC, was replicated, with rs3817586 on 1q31.1 attaining P = 2.5×10−4 and 2.9×10−5 in the within-family tests for DBP and MAP, respectively. We also identified regions of significant linkage for systolic and diastolic blood pressure on chromosomes 2q22 and 5p13, respectively. Further family-based association analysis of the linkage peak on chromosome 5 yielded a significant association (rs1605685, P<7×10−5) for DBP. This is the first combined linkage and association study of hypertension and its related quantitative traits with Chinese ancestry. The associations reported here account for the action of common variants whereas the discovery of linkage regions may point to novel targets for rare variant screening.
PMCID: PMC3286457  PMID: 22384028
9.  Study of the Effects of Total Flavonoids of Astragalus on Atherosclerosis Formation and Potential Mechanisms 
Astragalus mongholicus Bunge has long been used to treat cardiovascular disease in Chinese traditional medicine. However, its mechanisms are not fully understood. In this study, we explored potential mechanisms and protective effects of total flavonoids of Astragalus (TFA) on cardiovascular disease using in vitro experiments and diet-induced atherosclerotic rabbits. We identified six components and their proportion in TFA. The animal experiments showed that TFA significantly reduced plasma levels of total cholesterol and LDL cholesterol (P < 0.05 to 0.01), increased HDL cholesterol levels (P < 0.01), and reduced the aortic fatty streak area by 43.6 to 63.6% (P < 0.01). We also found that TFA scavenged superoxide and hydroxyl radicals and this effect increased with higher TFA concentration. In in vivo experiments, TFA effectively inhibited the free radical spectrum in the ischemia-reperfusion module. In conclusion, TFA was the active component of Astragalus mongholicus Bunge, which benefits cardiovascular disease attributing to the potent antioxidant activity to improve the atherosclerosis profile.
PMCID: PMC3306992  PMID: 22496932
10.  A single nucleotide polymorphism in APOA5 determines triglyceride levels in Hong Kong and Guangzhou Chinese 
European Journal of Human Genetics  2010;18(11):1255-1260.
Single nucleotide polymorphisms (SNPs) in the apolipoprotein A5 (APOA5) gene have been associated with hypertriglyceridaemia. We investigated which SNPs in the APOA5 gene were associated with triglyceride levels in two independent Chinese populations. In all, 1375 subjects in the Hong Kong Cardiovascular Risk Factor Prevalence Study were genotyped for five tagging SNPs chosen from HapMap. Replication was sought in 1996 subjects from the Guangzhou Biobank Cohort Study. Among the five SNPs, rs662799 (-1131T>C) was strongly related to log-transformed triglyceride levels among Hong Kong subjects (β=0.192, P=2.6 × 10−13). Plasma triglyceride level was 36.1% higher in CC compared to TT genotype. This association was confirmed in Guangzhou subjects (β=0.159, P=1.3 × 10−12), and was significantly irrespective of sex, age group, obesity, metabolic syndrome, hypertension, diabetes, smoking and alcohol drinking. The odds ratios and 95% confidence interval for plasma triglycerides ≥1.7 mmol/l associated with TC and CC genotypes were, respectively, 1.81 (1.37–2.39) and 2.22 (1.44–3.43) in Hong Kong and 1.27 (1.05–1.54) and 1.97 (1.42–2.73) in Guangzhou. Haplotype analysis suggested the association was due to rs662799 only. The corroborative findings in two independent populations indicate that the APOA5-1131T>C polymorphism is an important and clinically relevant determinant of plasma triglyceride levels in the Chinese population.
PMCID: PMC2987477  PMID: 20571505
apolipoproteins; triglycerides; hypertriglyceridaemia; single nucleotide polymorphisms
11.  Effects of Some Common Food Constituents on Cardiovascular Disease 
ISRN Cardiology  2011;2011:397136.
Cardiovascular diseases are the major cause of morbidity and mortality worldwide, and there is considerable interest in the role of dietary constituents and supplements in the prevention and treatment of these disorders. We reviewed the major publications related to potential effects on cardiovascular risk factors and outcomes of some common dietary constituents: carotenoids, flavonoid-rich cocoa, tea, red wine and grapes, coffee, omega-3 fatty acids, and garlic. Increased intake of some of these has been associated with reduced all-cause mortality or reduced incidence of myocardial infraction, stroke, and hypertension. However, although the evidence from observational studies is supportive of beneficial effects for most of these foodstuffs taken as part of the diet, potential benefits from the use of supplements derived from these natural products remain largely inconclusive.
PMCID: PMC3262529  PMID: 22347642
12.  Linkage of Angiotensinogen Gene Polymorphisms with Hypertension in a Sibling Study of Hong Kong Chinese 
Journal of hypertension  2010;28(6):1203-1209.
The angiotensinogen gene has been linked with human essential hypertension in Caucasians but the relationship in Asian populations has been less consistent. This study aimed to examine genetic associations between hypertension and the M235T, T174M, and G-217A polymorphisms of the angiotensinogen gene in Chinese siblings.
We studied members of 126 families with a hypertensive proband, including 434 siblings, of which 178 were hypertensive. Parental history of hypertension was recorded. The M235T, T174M, and G-217A polymorphisms were examined using a microarray method, validated by sequencing. The transmission disequilibrium test was applied to identify whether the genetic polymorphism loci were related to hypertension. Haplotype analysis of the combined polymorphisms was applied using the TRANSMIT program. Linkage study was conducted by applying the affected pedigree member method.
A significant over-transmission was observed for the T235 allele at the M235T polymorphism and hypertension (χ2=4.41, p=0.036), but not for the T174M and G-217A polymorphisms. The haplotype analysis showed a significant association with the haplotypes of paired markers (T174 and T235) with χ2 value of 8.131, p=0.004 (global test χ2=9.131, p=0.028). Linkage between M235T and hypertension was detected (T=-2.25, P=0.019), and a tendency for linkage with central obesity-related hypertension was found for the M235T and T174M polymorphisms (P=0.0087 and P=0.01).
The M235T and T174M variants, especially the T235 allele, contribute to an increased risk of hypertension in these Chinese subjects.
PMCID: PMC2908179  PMID: 20216084
angiotensinogen; hypertension; sibling study
13.  Febuxostat in the management of hyperuricemia and chronic gout: a review 
Febuxostat is a novel, potent, non-purine selective xanthine oxidase inhibitor, which in clinical trials demonstrated superior ability to lower and maintain serum urate levels below 6 mg/dL compared with conventionally used doses of allopurinol. Febuxostat was well tolerated in long term treatment in patients with hyperuricemia including those experiencing hypersensitity/intolerance to allopurinol. Dose adjustment appears unnecessary in patients with mild to moderate renal or liver insufficiency or advanced age. The most common adverse reactions reported were abnormal liver function tests, headache, and gastrointestinal symptoms, which were usually mild and transient. However, whether hepatotoxicity becomes a limitation in the use of febuxostat needs to be determined in further studies. An increased frequency of gout flares occurs for a prolonged period after treatment initiation, as with any aggressive lowering of serum urate, and prolonged prophylaxis with colchicine or NSAIDs is usually required. Febuxostat has been granted marketing authorization by the European Commission in early 2008 for the treatment of chronic hyperuricemia and gout. Febuxostat is the first major treatment alternative for gout in more than 40 years and is a promising alternative to allopurinol, although continued long-term surveillance on safety and efficacy is required.
PMCID: PMC2643102  PMID: 19337428
febuxostat; TEI-6720; TMX-67; gout; hyperuricemia; xanthine oxidase inhibitor
14.  Human Metapneumovirus-associated Atypical Pneumonia and SARS 
Emerging Infectious Diseases  2004;10(3):497-500.
Acute pneumonia developed in a previously healthy man during the outbreak of severe acute respiratory syndrome (SARS) in southern China in March 2003. Antibiotic treatment was ineffective, and he died 8 days after illness onset. Human metapneumovirus was isolated from lung tissue. No other pathogen was found. Other etiologic agents should thus be sought in apparent SARS cases when coronavirus infection cannot be confirmed.
PMCID: PMC3322781  PMID: 15109421
human metapneumovirus; respiratory tract infection; postmortem; SARS
15.  Lessons from the Severe Acute Respiratory Syndrome Outbreak in Hong Kong 
Emerging Infectious Diseases  2003;9(9):1042-1045.
Severe acute respiratory syndrome (SARS) is now a global public health threat with many medical, ethical, social, economic, political, and legal implications. The nonspecific signs and symptoms of this disease, coupled with a relatively long incubation period and the initial absence of a reliable diagnostic test, limited the understanding of the magnitude of the outbreak. This paper outlines our experience with public health issues that have arisen during this outbreak of SARS in Hong Kong. We confirmed that case detection, reporting, clear and timely dissemination of information, and strict infection control measures are essential in handling such an infectious disease outbreak. The need for an outbreak response unit is crucial to combat any future outbreak.
PMCID: PMC3016765  PMID: 14519237
Severe acute respiratory syndrome (SARS); Hong Kong; emerging infectious disease; outbreak control

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