Displaying publications 1 - 20 of 67 in total

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  1. Huang WC, Lin YH, Wu VC, Chen CH, Siddique S, Chia YC, et al.
    J Clin Hypertens (Greenwich), 2022 Sep;24(9):1194-1203.
    PMID: 36196469 DOI: 10.1111/jch.14558
    Arterial hypertension is a major risk factor for cardiovascular disease. The prevalence of primary aldosteronism (PA) ranges from 5% to 10% in the general hypertensive population and is regarded as one of the most common causes of secondary hypertension. There are two major causes of PA: bilateral adrenal hyperplasia and aldosterone-producing adenoma. The diagnosis of PA comprises screening, confirmatory testing, and subtype differentiation. The Endocrine Society Practice Guidelines for the diagnosis and treatment of PA recommends screening of patients at an increased risk of PA. These categories include patients with stage 2 and 3 hypertension, drug-resistant hypertension, hypertensive with spontaneous or diuretic-induced hypokalemia, hypertension with adrenal incidentaloma, hypertensive with a family history of early onset hypertension or cerebrovascular accident at a young age, and all hypertensive first-degree relatives of patients with PA. Recently, several studies have linked PA with obstructive sleep apnea and atrial fibrillation unexplained by structural heart defects and/or other conditions known to cause the arrhythmia, which may be partly responsible for the higher rates of cardiovascular and cerebrovascular accidents in patients with PA. The aim of this review is to discuss which patients should be screened for PA, focusing not only on well-established guidelines but also on additional groups of patients with a potentially higher prevalence of PA, as has been reported in recent research.
  2. Yam ML, Abdul Hafid SR, Cheng HM, Nesaretnam K
    Lipids, 2009 Sep;44(9):787-97.
    PMID: 19655189 DOI: 10.1007/s11745-009-3326-2
    Tocotrienols are powerful chain breaking antioxidant. Moreover, they are now known to exhibit various non-antioxidant properties such as anti-cancer, neuroprotective and hypocholesterolemic functions. This study was undertaken to investigate the anti-inflammatory effects of tocotrienol-rich fraction (TRF) and individual tocotrienol isoforms namely delta-, gamma-, and alpha-tocotrienol on lipopolysaccharide-stimulated RAW264.7 macrophages. The widely studied vitamin E form, alpha-tocopherol, was used as comparison. Stimulation of RAW264.7 with lipopolysaccharide induced the release of various inflammatory markers. 10 mcirog/ml of TRF and all tocotrienol isoforms significantly inhibited the production of interleukin-6 and nitric oxide. However, only alpha-tocotrienol demonstrated a significant effect in lowering tumor necrosis factor-alpha production. Besides, TRF and all tocotrienol isoforms except gamma-tocotrienol reduced prostaglandin E(2) release. It was accompanied by the down-regulation of cyclooxygenase-2 gene expression by all vitamin E forms except alpha-tocopherol. Collectively, the data suggested that tocotrienols are better anti-inflammatory agents than alpha-tocopherol and the most effective form is delta-tocotrienol.
  3. Huang HC, Cheng HM, Chia YC, Li Y, Van Minh H, Siddique S, et al.
    J Clin Hypertens (Greenwich), 2022 Sep;24(9):1187-1193.
    PMID: 36196464 DOI: 10.1111/jch.14554
    Recent trials have demonstrated the efficacy and safety of percutaneous renal sympathetic denervation (RDN) for blood pressure (BP)-lowering in patients with uncontrolled hypertension. Nevertheless, major challenges exist, such as the wide variation of BP-lowering responses following RDN (from strong response to no response) and lack of feasible and reproducible peri-procedural predictors for patient response. Both animal and human studies have demonstrated different patterns of BP responses following renal nerve stimulation (RNS), possibly related to varied regional proportions of sympathetic and parasympathetic nerve tissues along the renal arteries. Animal studies of RNS have shown that rapid electrical stimulation of the renal arteries caused renal artery vasoconstriction and increased norepinephrine secretion with a concomitant increase in BP, and the responses were attenuated after RDN. Moreover, selective RDN at sites with strong RNS-induced BP increases led to a more efficient BP-lowering effect. In human, when RNS was performed before and after RDN, blunted changes in RNS-induced BP responses were noted after RDN. The systolic BP response induced by RNS before RDN and blunted systolic BP response to RNS after RDN, at the site with maximal RNS-induced systolic BP response before RDN, both correlated with the 24-h ambulatory BP reductions 3-12 months following RDN. In summary, RNS-induced BP changes, before and after RDN, could be used to assess the immediate effect of RDN and predict BP reductions months following RDN. More comprehensive, large-scale and long term trials are needed to verify these findings.
  4. Tsoi K, Lam A, Tran J, Hao Z, Yiu K, Chia YC, et al.
    PMID: 36946438 DOI: 10.1111/jch.14610
    Hypertension remains the world's leading cause of premature death. Interventions such as exercise, diet modification, and pharmacological therapy remain the mainstay of hypertension treatment. Numerous systematic reviews and meta-analyses demonstrated the effectiveness of western exercises, such as aerobic exercise and resistance exercise, in reducing blood pressure in hypertensive patients. There is recently emerging evidence of blood pressure reduction with Chinese exercises, such as Tai Chi, Baduanjin, and Qigong. The current overview of systematic reviews aims to evaluate the quality and descriptively summarize the evidence for the effectiveness of western and Chinese exercises for hypertension management. Thirty-nine systematic reviews were included in this overview, with 15 of those being on Chinese exercise. Evidence suggests that exercise training, regardless of Western or Chinese exercise, generally reduced both systolic and diastolic blood pressure. High-intensity intermittent training did not further reduce blood pressure when compared to moderate-intensity continuous training. Conflicting results on the effectiveness of blood pressure reduction when comparing Chinese and Western exercise training were observed. This suggests the comparable effectiveness of Chinese exercise training, in particularly Tai Chi, to general or aerobic exercise training in terms of blood pressure reduction. The Chinese exercise modality and intensity may be more suitable for the middle-aged and elderly population.
  5. Kario K, Wang JG, Chia YC, Wang TD, Li Y, Siddique S, et al.
    J Clin Hypertens (Greenwich), 2022 Sep;24(9):1112-1120.
    PMID: 36196465 DOI: 10.1111/jch.14555
    Morning hypertension is an important clinical target in the management of hypertension for perfect 24-h blood pressure (BP) control. Morning hypertension is generally categorized into two types: "morning surge" type and "sustained nocturnal and morning hypertension" type. The "morning surge" type is characterized by an exaggerated morning blood pressure surge (MBPS), and the "sustained nocturnal and morning hypertension" type with continuous hypertension from nighttime to morning (non-dipper/riser type). They can be detected by home and ambulatory blood pressure measurements (HBPM and ABPM). These two forms of morning hypertension both increase the risk of cardiovascular and renal diseases, but may occur via different pathogenic mechanisms and are associated with different conditions. Morning hypertension should be treated to achieve a morning BP level of 
  6. Shin J, Wang JG, Chia YC, Kario K, Chen CH, Cheng HM, et al.
    PMID: 37878534 DOI: 10.1111/jch.14729
    For adopting recently introduced hypertension phenotypes categorized using office and out of office blood pressure (BP) for the diagnosis of hypertension and antihypertension drug therapy, it is mandatory to define the corresponding out of office BP with the specific target BP recommended by the major guidelines. Such conditions include white-coat hypertension (WCH), masked hypertension (MH), white-coat uncontrolled hypertension (WUCH), and masked uncontrolled hypertension (MUCH). Here, the authors review the relevant literature and discuss the related issue to facilitate the use of corresponding BPs for proper diagnosis of WCH, MH, WUCH, and MUCH in the setting of standard target BP as well as intensive target BP. The methodology of deriving the corresponding BP has evolved from statistical methods such as standard deviation, percentile value, and regression to an outcome-based approach using pooled international cohort study data and comparative analysis in randomized clinical trials for target BPs such as the SPRINT and STEP studies. Corresponding BPs to 140/90 and 130/80 mm Hg in office BP is important for safe and strict achievement of intensive BP targets. The corresponding home, daytime, and 24-h BPs to 130/80 mm Hg in office BP are 130/80, 130/80, and 125/75 mm Hg, respectively. However, researchers have found some discrepancies among the home corresponding BPs. As tentative criterion for de-escalation of antihypertensive therapy as shown in European guidelines was 120 mm Hg in office BP, corresponding home, daytime, and 24-h systolic BPs to 120 mm Hg in office systolic BP are 120, 120, and 115 mm Hg, respectively.
  7. Wang JG, Li Y, Chia YC, Cheng HM, Minh HV, Siddique S, et al.
    J Clin Hypertens (Greenwich), 2021 03;23(3):435-439.
    PMID: 33484617 DOI: 10.1111/jch.14194
    The prevalence of hypertension is high and still increasing in almost all communities regardless of high, middle, or low income. The control rate remains low in most countries. Telemedicine offers possibilities to improve blood pressure control. The past two decades witnessed the fast evolving telecommunication from telephone transmission to smart mobile phone technology for telemedicine. There is some evidence from randomized controlled trials that telemonitoring improves blood pressure control. However, it requires co-interventions. The emerging new technology may offer even more possibilities in telemonitoring and co-interventions, for instance, an interactive platform between patients and health professionals for the management of hypertension. Telemedicine might ultimately change the situation of the unsatisfactory management of hypertension in many communities. It helps fully utilize antihypertensive treatment, the most effective cardiovascular prevention, to achieve the goal of ending atherosclerosis and arteriosclerosis in humans.
  8. Lin HJ, Pan HY, Chen CH, Cheng HM, Chia YC, Sogunuru GP, et al.
    J Clin Hypertens (Greenwich), 2022 Sep;24(9):1161-1173.
    PMID: 36196472 DOI: 10.1111/jch.14549
    Home blood pressure (HBP) has been recognized as a prognostic predictor for cardiovascular events, and integrated into the diagnosis and management of hypertension. With increasing accessibility of oscillometric blood pressure devices, HBP monitoring is easy to perform, more likely to obtain reliable estimation of blood pressures, and feasible to document long-term blood pressure variations, compared to office and ambulatory blood pressures. To obtain reliable HBP estimates, a standardized HBP monitoring protocol is essential. A consensus regarding the optimal duration and frequency of HBP monitoring is yet to be established. Based on the current evidence, the "722" protocol, which stands for two measurements on one occasion, two occasions a day (morning and evening), and over a consecutive of 7 days, is most commonly used in clinical studies and recommended in relevant guidelines and consensus documents. HBP monitoring based on the "722" protocol fulfills the minimal requirement of blood pressure measurements to achieve agreement of blood pressure classifications defined by office blood pressures and to predict cardiovascular risks. In the Taiwan HBP consensus, the frequency of repeating the "722" protocol of HBP monitoring according to different scenarios of hypertension management, from every 2 weeks to 3 months, is recommended. It is reasonable to conclude that the "722" protocol for HBP monitoring is clinically justified and can serve as a basis for standardized HBP monitoring.
  9. Kario K, Chia YC, Siddique S, Turana Y, Li Y, Chen CH, et al.
    PMID: 35172037 DOI: 10.1111/jch.14440
    Asia is a large continent and there is significant diversity between countries and regions. Over the last 30 years, absolute blood pressure (BP) levels in Asia have increased to a greater extent than those in other regions. In diverse Asia-Pacific populations, for choosing an Asia-specific approach to hypertension management is important to prevent target organ damage and cardiovascular diseases. In this consensus document of HOPE Asia Network, we introduce seven action approaches for management of hypertension in Asia.
  10. Foong YT, Cheng HM, Sam CK, Dillner J, Hinderer W, Prasad U
    Int J Cancer, 1990 Jun 15;45(6):1061-4.
    PMID: 1693600
    The Epstein-Barr virus nuclear antigen I (EBNA I) is the only latent EBV antigen consistently expressed in malignant tissues of the nasopharynx. A 20-amino-acid synthetic peptide, p107 contains a major epitope of EBNA I. We tested sera from 210 patients with nasopharyngeal carcinoma (NPC) and from 128 normal individuals (NHS) for IgA antibodies to p107 using an enzyme-linked immunosorbent assay (ELISA). Whereas 191/210 (91%) of NPC patients had IgA antibodies to p107, only 17/128 (13.3%) of NHS had such antibodies and only 6/57 (10.5%) of sera from patients with malignancies other than NPC had IgA-p107 reactivity. Thirty-nine salivary samples from 46 NPC patients (84.8%) also contained IgA-p107 antibodies whereas only 3/42 (7.1%) of normal saliva samples were IgA-p107 positive. The results suggest that IgA antibodies to EBNA I may become a useful, easily measurable, marker for NPC.
  11. Mathew A, Cheng HM, Sam CK, Prasad U
    Clin. Immunol. Immunopathol., 1994 May;71(2):164-8.
    PMID: 7514112
    Inhibition studies were carried out to study possible cross-reactivity between a peptide fragment of the Epstein-Barr virus nuclear antigen, EBNA-1, and keratin/collagen. The 20-amino acid peptide (pAG), derived from a glycine-alanine repeat region of EBNA-1, uniquely makes up about one-third of the viral protein and is a dominant IgA antigenic epitope in patients with nasopharyngeal carcinoma (NPC). A small percentage of normal human sera (NHS) also binds pAG and this reactivity is examined in this study. Ten percent (2/20) and 13.4% (2/15) of IgA-pAG-positive NPC sera and NHS, respectively, were significantly inhibited by keratin in a competitive ELISA system. Conversely, 31.6% (6/19) and 30.8% (4/13) of IgA-keratin-positive NPC sera and NHS, respectively, were significantly inhibited by pAG. This indicated minimum cross-reactivity between IgA serum antibodies to EBNA-1 and keratin. Using collagen as inhibitor, none of 18 and only 2/13 IgA-pAG-positive NPC sera and NHS, respectively, were inhibited. In the collagen ELISA system, only 2/19 (10.5%) and 4/25 (16%) of IgA-collagen-positive NPC sera and NHS, respectively, were inhibited with pAG. Therefore, cross-reactivity with collagen was also low. IgA-pAG-positive NHS may therefore not be a false positive phenomenon, but whether it may represent an early serological profile related to NPC carcinogenesis remains to be determined.
  12. Cheng HM, Foong YT, Mathew A, Sam CK, Dillner J, Prasad U
    J Virol Methods, 1993 Apr;42(1):45-51.
    PMID: 7686558
    An ELISA using the Epstein-Barr virus nuclear antigen 1 (EBNA 1) was found to detect selectively specific IgA in sera from patients with nasopharyngeal carcinoma (NPC). The antigen, p107, was a 20-amino acid synthetic peptide, representing a major epitope of EBNA 1.267/294 (90.8%) of NPC patients had IgA antibodies to p107 but in normal individuals, only 41/577 (7.1%) had IgA/p107. In sera from patients with other cancers, 11/77 (14.3%) had IgA/p107 reactivity. 124 IgA/VCA positive and 86 IgA/VCA negative NPC sera were also tested for IgA/p107 binding in ELISA. The majority of IgA/VCA positive sera (117) also contained IgA/p107 antibodies. Of interest was the detection of 74/86 IgA/p107 reactive sera in the IgA/VCA negative group. The results suggest that the IgA/p107 ELISA could become a useful, complementary screening assay to the IgA/VCA immunofluorescence test for detection of NPC.
  13. Li H, Xu TY, Li Y, Chia YC, Buranakitjaroen P, Cheng HM, et al.
    J Clin Hypertens (Greenwich), 2022 Sep;24(9):1180-1186.
    PMID: 36196467 DOI: 10.1111/jch.14556
    There is emerging evidence that α1-blockers can be safely used in the treatment of hypertension. These drugs can be used in almost all hypertensive patients for blood pressure control. However, there are several special indications. Benign prostatic hyperplasia is a compelling indication of α1-blockers, because of the dual treatment effect on both high blood pressure and lower urinary tract symptoms. Many patients with resistant hypertension would require α1-blockers as add-on therapy. Primary aldosteronism screen is a rapidly increasing clinical demand in the management of hypertension, where α1-blockers are useful for blood pressure control in the preparation for the measurement of plasma aldosterone and renin. Nonetheless, α1-blockers have to be used under several considerations. Among the currently available agents, only long-acting α1-blockers, such as doxazosin gastrointestinal therapeutic system 4-8 mg daily and terazosin 2-4 mg daily, should be chosen. Orthostatic hypotension is a concern with the use of α1-blockers especially in the elderly, and requires careful initial bedtime dosing and avoiding overdosing. Fluid retention is potentially also a concern, which may be overcome by combining an α1-blocker with a diuretic.
  14. Palanisamy U, Cheng HM, Masilamani T, Subramaniam T, Ling LT, Radhakrishnan AK
    Food Chem, 2008 Jul 1;109(1):54-63.
    PMID: 26054264 DOI: 10.1016/j.foodchem.2007.12.018
    The rind of rambutan, which is normally discarded was found to contain extremely high antioxidant activity when assessed using several methods. Although having a yield of only 18%, the ethanolic rambutan rind extract had a total phenolic content of 762±10mg GAE/g extract, which is comparable to that of a commercial preparation of grape seed extract. Comparing the extract's pro-oxidant capabilities with vitamin C, α-tocopherol, grape seed and green tea, the rind had the lowest pro-oxidant capacity. In addition, the extract at 100μg/ml was seen to limit oxidant-induced cell death (DPPH at 50μM) by apoptosis to an extent similar to that of grape seed. The extracts were not cytotoxic to normal mouse fibroblast cells or splenocytes while the powderised rind was seen to have heavy metals contents far below the permissible levels for nutraceuticals. Our study for the first time reveals the high phenolic content, low pro-oxidant capacity and strong antioxidant activity of the extract from rind of Nephelium lappaceum. This extract, either alone or in combination with other active principles, can be used in cosmetic, nutraceutical and pharmaceutical applications.
  15. Ling LT, Palanisamy UD, Cheng HM
    Molecules, 2010 Nov;15(11):7884-92.
    PMID: 21060296 DOI: 10.3390/molecules15117884
    The antioxidant activity of several Malaysian plant extracts was analyzed simultaneously with their pro-oxidant capacity. This ratio represents an index (ProAntidex) of the net free radical scavenging ability of whole plant extracts. We observed that ethanolic extracts of Nephelium lappaceum peel, Fragaria x ananassa leaf, Lawsonia inermis leaf, Syzygium aqueum leaf and grape seed had a lower Pro-Antidex than the commercially available Emblica™ extract which is an antioxidant agent with very low pro-oxidant activity. Among the aqueous extracts, Lawsonia inermis leaf, Nephelium mutobile leaf and grape seed had lower pro-oxidant activity compared to the Emblica™ extract. Among these extracts, aqueous extract of Nephelium mutobile leaf had a very low index of 0.05 compared to 0.69 for Emblica™. Most of the extracts had a far lower ProAntidex compared to the Vitamin C. The index enables us to identify extracts with high net free radical scavenging activity potential. The ProAntidex is beneficial as a screening parameter to the food industries and healthcare.
  16. Fairus S, Nor RM, Cheng HM, Sundram K
    Am J Clin Nutr, 2006 Oct;84(4):835-42.
    PMID: 17023711
    BACKGROUND: The detection of tocotrienols in human plasma has proven elusive, and it is hypothesized that they are rapidly assimilated and redistributed in various mammalian tissues.

    OBJECTIVE: The primary study objective was to evaluate the postprandial fate of tocotrienols and alpha-tocopherol in human plasma and lipoproteins.

    DESIGN: Seven healthy volunteers (4 males, 3 females) were administered a single dose of vitamin E [1011 mg palm tocotrienol-rich fraction (TRF) or 1074 mg alpha-tocopherol] after a 7-d conditioning period with a tocotrienol-free diet. Blood was sampled at baseline (fasted) and 2, 4, 5, 6, 8, and 24 h after supplementation. Concentrations of tocopherol and tocotrienol isomers in plasma, triacylglycerol-rich particles (TRPs), LDLs, and HDLs were measured at each interval.

    RESULTS: After intervention with TRF, plasma tocotrienols peaked at 4 h (4.79 +/- 1.2 microg/mL), whereas alpha-tocopherol peaked at 6 h (13.46 +/- 1.68 microg/mL). Although tocotrienols were similarly detected in TRPs, LDLs, and HDLs, tocotrienol concentrations were significantly lower than alpha-tocopherol concentrations. In comparison, plasma alpha-tocopherol peaked at 8 h (24.3 +/- 5.22 microg/mL) during the alpha-tocopherol treatment and emerged as the major vitamin E isomer detected in plasma and lipoproteins during both the TRF and the alpha-tocopherol treatments.

    CONCLUSIONS: Tocotrienols are detected in postprandial plasma, albeit in significantly lower concentrations than is alpha-tocopherol. This finding confirms previous observations that, in the fasted state, tocotrienols are not detected in plasma. Tocotrienol transport in lipoproteins appears to follow complex biochemically mediated pathways within the lipoprotein cascade.

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