Displaying publications 1 - 20 of 39 in total

Abstract:
Sort:
  1. Abdullah M, Chai PS, Chong MY, Tohit ER, Ramasamy R, Pei CP, et al.
    Cell Immunol, 2012;272(2):214-9.
    PMID: 22078320 DOI: 10.1016/j.cellimm.2011.10.009
    Differences in gender immune response have resulted in differences in immune protection and susceptibility to inflammatory diseases. Cultured peripheral blood mononuclear cells (PBMC) are widely used in immunomodulation studies, yet the influence of gender is usually not considered. We examined the effect of in vitro culture and phytohaemagglutinin (PHA) stimulation on PBMC lymphocyte subsets using flowcytometry. Full blood counts of whole blood showed higher levels of lymphocyte in male subjects. Lymphocyte subsets enumeration revealed higher NK cell counts in males and higher B cells in females. Cultured PBMC resulted in significant increases in B and total T cell percentages among females and NK cells among males. PHA stimulated significantly increased percentages of NK and total T cells in males and total activated T cells (CD69+) in females. Our results showed significant gender differences in lymphocyte subsets in cultured conditions. This may affect experimental outcome.
  2. Park YC, Yang SY, Chong MY, Kanba S, Sartorius N, Shinfuku N, et al.
    Psychiatry Investig, 2018 Oct;15(10):1007-1008.
    PMID: 30373360 DOI: 10.30773/pi.2018.09.06
    The REAP-AP study recruited 3,746 patients with schizophrenia, in March and April 2016, from 71 centers in 15 Asian countries/territories namely Bangladesh, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, Myanmar, Pakistan, Singapore, Sri Lanka, Taiwan, Thailand and Vietnam. Our findings reveal a trend according to which high dose antipsychotic prescription is more prevalent in Eastern Asia (especially, Japan and Korea) than in other regions of Asia. This historical factor may be associated with our finding of an Eastern Asian preponderance of high dose antipsychotic prescription.
  3. Chong MY, Gu B, Armour CH, Dokos S, Ong ZC, Xu XY, et al.
    Biomech Model Mechanobiol, 2022 Feb;21(1):261-275.
    PMID: 35079931 DOI: 10.1007/s10237-021-01534-5
    False lumen thrombosis (FLT) in type B aortic dissection has been associated with the progression of dissection and treatment outcome. Existing computational models mostly assume rigid wall behavior which ignores the effect of flap motion on flow and thrombus formation within the FL. In this study, we have combined a fully coupled fluid-structure interaction (FSI) approach with a shear-driven thrombosis model described by a series of convection-diffusion reaction equations. The integrated FSI-thrombosis model has been applied to an idealized dissection geometry to investigate the interaction between vessel wall motion and growing thrombus. Our simulation results show that wall compliance and flap motion can influence the progression of FLT. The main difference between the rigid and FSI models is the continuous development of vortices near the tears caused by drastic flap motion up to 4.45 mm. Flap-induced high shear stress and shear rates around tears help to transport activated platelets further to the neighboring region, thus speeding up thrombus formation during the accelerated phase in the FSI models. Reducing flap mobility by increasing the Young's modulus of the flap slows down the thrombus growth. Compared to the rigid model, the predicted thrombus volume is 25% larger using the FSI-thrombosis model with a relatively mobile flap. Furthermore, our FSI-thrombosis model can capture the gradual effect of thrombus growth on the flow field, leading to flow obstruction in the FL, increased blood viscosity and reduced flap motion. This model is a step closer toward simulating realistic thrombus growth in aortic dissection, by taking into account the effect of intimal flap and vessel wall motion.
  4. Chong MY, Gu B, Chan BT, Ong ZC, Xu XY, Lim E
    Int J Numer Method Biomed Eng, 2020 12;36(12):e3399.
    PMID: 32862487 DOI: 10.1002/cnm.3399
    A monolithic, fully coupled fluid-structure interaction (FSI) computational framework was developed to account for dissection flap motion in acute type B aortic dissection (TBAD). Analysis of results included wall deformation, pressure, flow, wall shear stress (WSS), von Mises stress and comparison of hemodynamics between rigid wall and FSI models. Our FSI model mimicked realistic wall deformation that resulted in maximum compression of the distal true lumen (TL) by 21.4%. The substantial movement of intimal flap mostly affected flow conditions in the false lumen (FL). Flap motion facilitated more flow entering the FL at peak systole, with the TL to FL flow split changing from 88:12 in the rigid model to 83:17 in the FSI model. There was more disturbed flow in the FL during systole (5.8% FSI vs 5.2% rigid) and diastole (13.5% FSI vs 9.8% rigid), via a λ2 -criterion. The flap-induced disturbed flow near the tears in the FSI model caused an increase of local WSS by up to 70.0% during diastole. This resulted in a significant reduction in the size of low time-averaged WSS (TAWSS) regions in the FL (113.11 cm2 FSI vs 177.44 cm2 rigid). Moreover, the FSI model predicted lower systolic pressure, higher diastolic pressure, and hence lower pulse pressure. Our results provided new insights into the possible impact of flap motion on flow in aortic dissections, which are particularly important when evaluating hemodynamics of acute TBAD. NOVELTY STATEMENT: Our monolithic fully coupled FSI computational framework is able to reproduce experimentally measured range of flap deformation in aortic dissection, thereby providing novel insights into the influence of physiological flap motion on the flow and pressure distributions. The drastic flap movement increases the flow resistance in the true lumen and causes more disturbed flow in the false lumen, as visualized through the λ2 criterion. The flap-induced luminal pressure is dampened, thereby affecting pressure measures, which may serve as potential prognostic indicators for late complications in acute uncomplicated TBAD patients.
  5. Jumat NR, Chong MY, Seman Z, Jamaluddin R, Wong NK, Abdullah M
    Front Immunol, 2017;8:680.
    PMID: 28649252 DOI: 10.3389/fimmu.2017.00680
    Sexual dimorphism in immune response is widely recognized, but few human studies have observed this distinction. Food with endo-immunomodulatory potential may reveal novel sex-biased in vivo interactions. Immunomodulatory effects of Carica papaya were compared between healthy male and female individuals. Volunteers were given fixed meals supplemented with papaya for 2 days. Changes in blood immune profiles and hormone levels were determined. In females, total natural killer (NK) cell percentages decreased (12.7 ± 4.4 vs 14.6 ± 5.8%, p = 0.018, n = 18) while B cells increased (15.2 ± 5.5 vs 14.5 ± 5.0, p = 0.037, n = 18) after papaya consumption. Increased 17β-estradiol (511.1 ± 579.7 vs 282.7 ± 165.0 pmol/l, p = 0.036, n = 9) observed in females may be crucial to this change. Differentiation markers (CD45RA, CD69, CD25) analyzed on lymphocytes showed naïve (CD45RA(+)) non-CD4(+) lymphocytes were reduced in females (40.7 ± 8.1 vs 46.8 ± 5.4%, p = 0.012, n = 8) but not males. A general suppressive effect of papaya on CD69(+) cells, and higher percentage of CD69(+) populations in females and non-CD4 lymphocytes, may be relevant. CD107a(+) NK cells were significantly increased in males (16.8 ± 7.0 vs 14.7 ± 4.8, p = 0.038, n = 9) but not females. Effect in females may be disrupted by the action of progesterone, which was significantly correlated with this population (R = 0.771, p = 0.025, n = 8) after papaya consumption. In males, total T helper cells were increased (33.4 ± 6.4 vs 32.4 ± 6.1%, p = 0.040, n = 15). Strong significant negative correlation between testosterone and CD25(+)CD4(+) lymphocytes, may play a role in the lower total CD4(+) T cells reported in males. Thus, dissimilar immune profiles were elicited in the sexes after papaya consumption and may have sex hormone influence.
  6. Abdullah M, Chai PS, Loh CY, Chong MY, Quay HW, Vidyadaran S, et al.
    Mol Nutr Food Res, 2011 May;55(5):803-6.
    PMID: 21520494 DOI: 10.1002/mnfr.201100087
    Fruit and vegetables have therapeutic potential as they dampen inflammation, have no known side-effects and as whole foods have prospective additive and synergistic benefits. Th1 (IFN-γ(+) CD4(+))/Th2 (IL-4(+)CD4(+)) T cells play a vital role in mediating inflammatory responses and may be regulated by regulatory T cells (Tregs). Effects of Carica papaya on cells of healthy individuals were determined using flow cytometry methods. Significant down-regulation of IFN-γ(+) CD4(+) (p=0.03, n=13), up-regulation of IL-4(+) CD4(+) (p=0.04, n=13) T cells and up-regulation of CD3(+) CD4(+) CD25(+) CD127(-) (p=0.001, n=15) Tregs were observed after papaya consumption. In vitro cultures showed up-regulation of Tregs in male subjects and was significantly associated with levels of IL-1β in culture supernatants (R(2) =0.608, p=0.04, n=12). Other inflammatory cytokines were significantly suppressed. Papaya consumption may exert an anti-inflammatory response mediated through Tregs and have potential in alleviating inflammatory conditions.
  7. Park SC, Lee MS, Hahn SW, Si TM, Kanba S, Chong MY, et al.
    Acta Neuropsychiatr, 2016 Dec;28(6):337-345.
    PMID: 27305958
    Using data from the Research on Asian Psychotropic Prescription Patterns for Antidepressants (REAP-AD) study, we aimed to present the rates and clinical correlates of suicidal thoughts/acts in patients recruited from a total of 40 centres in 10 Asian countries/areas: China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, Singapore, Taiwan, and Thailand.
  8. Grover S, Avasthi A, Tripathi A, Tanra AJ, Chee KY, He YL, et al.
    East Asian Arch Psychiatry, 2015 Sep;25(3):99-107.
    PMID: 26429836
    Objective: To evaluate the prescription pattern of antidepressants in patients with medical co-morbidity from major psychiatric centres in Asia.
    Methods: The Research on Asian Psychotropic Prescription Pattern for Antidepressants (REAP-AD 2013) collected data from 42 psychiatric centres in 10 Asian countries and regions. Antidepressant prescriptions of 2320 patients with various psychiatric disorders were evaluated. Of these, 370 patients who had specified medical co-morbidities formed the study cohort.
    Results: Escitalopram (20%) and mirtazapine (20%) were the most commonly prescribed antidepressants in patients with medical co-morbidity followed by sertraline (16%), trazodone (15%), and paroxetine (12%). Overall, more than half (52%; 247/476) of prescriptions comprised selective serotonin reuptake inhibitors. Slightly less than two-thirds (63%; n = 233) of patients received at least 1 selective serotonin reuptake inhibitor. In addition, 79% of patients were prescribed only 1 antidepressant. The mean number of antidepressants used per patient was 1.25 (standard deviation, 0.56). There were subtle differences in the most preferred antidepressant across medical illnesses such as diabetes mellitus, liver dysfunction, acid peptic disease, and cerebrovascular disease. Differences were also seen in prescription patterns across different countries.
    Conclusion: Although selective serotonin reuptake inhibitors formed the bulk of antidepressant
    prescriptions in the presence of medical co-morbidity, mirtazapine was also commonly used in the presence of medical co-morbidities. Specified medical morbidities do influence the selection of antidepressants.
    Key words: Antidepressive agents; Asia; Comorbidity
  9. Chee KY, Tripathi A, Avasthi A, Chong MY, Xiang YT, Sim K, et al.
    East Asian Arch Psychiatry, 2016 Mar;26(1):10-7.
    PMID: 27086755
    Objective: Pharmacotherapy of depression in children and adolescents is complex. In the absence of research into the efficacy and safety of antidepressants in this group of patients, their off-label prescription is common. This paper aimed to illustrate the prescription pattern of antidepressants in children and adolescents from major psychiatric centres in Asia.
    Methods: The Research on Asia Psychotropic Prescription Pattern on Antidepressants worked
    collaboratively in 2013 to study the prescription pattern of antidepressants in Asia using a unified research protocol and questionnaire. Forty psychiatric centres from 10 Asian countries / regions participated and 2321 antidepressant prescriptions were analysed.
    Results: A total of 4.7% antidepressant prescriptions were for children and adolescents. Fluoxetine, sertraline, and escitalopram were the most common antidepressants prescribed for children and adolescents. Almost one-third (30.3%) of prescriptions were for diagnoses other than depressive and anxiety disorders. There was less antidepressant polypharmacy and concomitant use of benzodiazepine, but more concomitant use of antipsychotics in children and adolescents compared with adults.
    Conclusion: Off-label use of antidepressants in children and adolescents was reported by 40 Asian psychiatric institutions that participated in the study. In-service education and regulatory mechanisms should be reinforced to ensure efficacy and safety of antidepressants in children and adolescents.
    Key words: Adolescent; Antidepressive agents; Child; Ethnopsychology
  10. Park SC, Oh HS, Tripathi A, Abraham Kallivayalil R, Avasthi A, Grover S, et al.
    Nord J Psychiatry, 2019 Jun 26.
    PMID: 31240984 DOI: 10.1080/08039488.2019.1632381
    Background: Although cannabis use has been linked with schizophrenia in a dose-response pattern, to our knowledge, the relationship between cannabis and schizophrenia has rarely been reported in Asian population. Aim: We compared the clinical characteristics and psychotropic prescription patterns between cannabis users and non-users among Asian patients with schizophrenia. Moreover, we aimed to identify the independent correlates of cannabis use in these subjects. Methods: We performed the analysis of the data from the Research on Asian Psychotropic Prescription Patterns for Antipsychotics (REAP-AP), a collaborative consortium survey used to collate the prescription patterns for antipsychotic and other psychotropic medications in patients with schizophrenia in Asia. We included 132 schizophrenia patients in the group of lifetime cannabis use and 1756 in the group that had never used cannabis. A binary logistic model was fitted to detect the clinical correlates of lifetime cannabis use. Results: Adjusting for the effects of age, sex, geographical region, income group, duration of untreated psychosis, and Charlson comordity index level, a binary logistic regression model revealed that lifetime cannabis use was independently associated with aggressive behavior [adjusted odds ratio (aOR) = 1.582, 95% confidence interval (CI) = 1.006-2.490, p = .047] and with long-acting injectable antipsychotic treatment (aOR = 1.796, 95% CI = 1.444-2.820, p = .001). Conclusion: Our findings indicate a close link between lifetime cannabis use and aggressive behavior. The use of long-acting, injectable antipsychotics preferentially treats the aggressive behavior cannabis users among patients with schizophrenia in Asia, especially, the South or Southeast Asia.
  11. Dong M, Zeng LN, Zhang Q, Yang SY, Chen LY, Sim K, et al.
    J Geriatr Psychiatry Neurol, 2019 11;32(6):304-311.
    PMID: 31480982 DOI: 10.1177/0891988719862636
    BACKGROUND AND OBJECTIVE: Antipsychotic polypharmacy (APP) is a controversial topic in the treatment of older adults with schizophrenia. The objective of this study was to examine the use of APP in older adult Asian patients with schizophrenia and its associated demographic and clinical factors.

    METHODS: This study was based on the fourth survey of the consortium known as the Research on Asian Psychotropic Prescription Pattern for Antipsychotics. Fifteen Asian countries/territories participated in this survey, including Bangladesh, Mainland China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, Myanmar, Pakistan, Singapore, Sri Lanka, Taiwan, Thailand, and Vietnam. Basic demographic and clinical characteristics were collected using a standardized data collection form.

    RESULTS: Among the 879 older adults with schizophrenia included in the survey, the rate of APP was 40.5%. Multiple logistic regression analysis revealed that higher antipsychotic doses (P < .001, odds ratio [OR] = 1.003, 95% confidence interval [CI]: 1.002-1.003), longer duration of illness (P = .02, OR = 1.845, 95% CI: 1.087-3.132), and the prescription of anticholinergics (P < .001, OR = 1.871, 95% CI: 1.329-2.635), second-generation antipsychotics (P = .001, OR = 2.264, 95% CI: 1.453-3.529), and first-generation antipsychotics (P < .001, OR = 3.344, 95% CI: 2.307-4.847) were significantly associated with APP.

    CONCLUSION: Antipsychotic polypharmacy was common in older adult Asian patients with schizophrenia. Compared to the results of previous surveys, the use of APP showed a declining trend over time. Considering the general poor health status of older patients with schizophrenia and their increased risk of drug-induced adverse events, the use of APP in this population needs careful consideration.

  12. Park SC, Kim GM, Kato TA, Chong MY, Lin SK, Yang SY, et al.
    Nord J Psychiatry, 2021 Jan;75(1):9-17.
    PMID: 32580668 DOI: 10.1080/08039488.2020.1777462
    BACKGROUND: Network analysis provides a new viewpoint that explicates intertwined and interrelated symptoms into dynamic causal architectures of symptom clusters. This is a process called 'symptomics' and is concurrently applied to various areas of symptomatology.

    AIMS: Using the data from Research on Asian Psychotropic Prescription Patterns for Antipsychotics (REAP-AP), we aimed to estimate a network model of extrapyramidal syndrome in patients with schizophrenia.

    METHODS: Using data from REAP-AP, extrapyramidal symptoms of 1046 Asian patients with schizophrenia were evaluated using the nine items of the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS). The estimated network of the ordered-categorical DIEPSS items consisted of nodes (symptoms) and edges (interconnections). A community detection algorithm was also used to identify distinctive symptom clusters, and correlation stability coefficients were used to evaluate the centrality stability.

    RESULTS: An interpretable level of node strength centrality was ensured with a correlation coefficient. An estimated network of extrapyramidal syndrome showed that 26 (72.2%) of all possible 35 edges were estimated to be greater than zero. Dyskinesia was most centrally situated within the estimated network. In addition, earlier antipsychotic-induced extrapyramidal symptoms were divided into three distinctive clusters - extrapyramidal syndrome without parkinsonism, postural instability and gait difficulty-dominant parkinsonism, and tremor-dominant parkinsonism.

    CONCLUSIONS: Our findings showed that dyskinesia is the most central domain in an estimated network structure of extrapyramidal syndrome in Asian patients with schizophrenia. These findings are consistent with the speculation that acute dystonia, akathisia, and parkinsonism could be the risk factors of tardive dyskinesia.

  13. Park SC, Jang EY, Xiang YT, Kanba S, Kato TA, Chong MY, et al.
    Psychiatry Clin Neurosci, 2020 Jun;74(6):344-353.
    PMID: 32048773 DOI: 10.1111/pcn.12989
    AIM: We aimed to estimate the network structures of depressive symptoms using network analysis and evaluated the geographic regional differences in theses network structures among Asian patients with depressive disorders.

    METHODS: Using data from the Research on Asian Psychotropic Prescription Patterns for Antidepressants (REAP-AD), the network of the ICD-10 diagnostic criteria for depressive episode was estimated from 1174 Asian patients with depressive disorders. The node strength centrality of all ICD-10 diagnostic criteria for a depressive episode was estimated using a community-detection algorithm. In addition, networks of depressive symptoms were estimated separately among East Asian patients and South or Southeast Asian patients. Moreover, networks were estimated separately among Asian patients from high-income countries and those from middle-income countries.

    RESULTS: Persistent sadness, fatigue, and loss of interest were the most centrally situated within the network of depressive symptoms in Asian patients with depressive disorders overall. A community-detection algorithm estimated that when excluding psychomotor disturbance as an outlier, the other nine symptoms formed the largest clinically meaningful cluster. Geographic and economic variations in networks of depressive symptoms were evaluated.

    CONCLUSION: Our findings demonstrated that the typical symptoms of the ICD-10 diagnostic criteria for depressive episode are the most centrally situated within the network of depressive symptoms. Furthermore, our findings suggested that cultural influences related to geographic and economic distributions of participants could influence the estimated depressive symptom network in Asian patients with depressive disorders.

  14. Chon Park Y, Kanba S, Chong MY, Tripathi A, Kallivayalil RA, Avasthi A, et al.
    Kaohsiung J. Med. Sci., 2018 Feb;34(2):113-119.
    PMID: 29413227 DOI: 10.1016/j.kjms.2017.09.009
    Our study aimed to assess the psychometric validity of the conceptual disorganization item and other items of the Brief Psychiatric Rating Scale (BPRS) for detecting disorganized speech in patients with schizophrenia. We included 357 schizophrenia patients with disorganized speech and 1082 without disorganized speech from the survey centers in India, Indonesia, Japan, Malaysia, and Taiwan, using the data from the Research on Asian Psychotropic Patterns for Antipsychotics (REAP-AP) study. After adjusting the effects of confounding variables, a binary logistic regression model was fitted to identify BPRS items independently associated with disorganized speech. Receiver operating characteristic (ROC) curves were used to identify optimum cut-off scores and their sensitivities and specificities for detecting disorganized speech. After adjusting the effects of confounding variables, the fitted binary logistic regression model indicated that conceptual disorganization (P 
  15. Chee KY, Tripathi A, Avasthi A, Chong MY, Sim K, Yang SY, et al.
    Asia Pac Psychiatry, 2015 Dec;7(4):366-74.
    PMID: 25706498 DOI: 10.1111/appy.12176
    Research in prescription pattern of antidepressants in Asia is lacking. This study aims to compare the antidepressants prescription pattern in Asia in 2003-2004 and 2013.
  16. Chee KY, Tripathi A, Avasthi A, Chong MY, Xiang YT, Sim K, et al.
    Asia Pac Psychiatry, 2015 Sep;7(3):276-85.
    PMID: 25641910 DOI: 10.1111/appy.12170
    This study was to assess differences in the symptom profile of depressive illness across various countries/territories in Asia. The study was a part of the Research on Asia Psychotropic Prescription project. The participating countries/territories include China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, Singapore, Taiwan, and Thailand.
  17. Xiang YT, Dickerson F, Kreyenbuhl J, Ungvari GS, Wang CY, Si TM, et al.
    Int Psychogeriatr, 2012 Jun;24(6):1002-8.
    PMID: 22300452 DOI: 10.1017/S1041610211002791
    This study examined the use of low doses of antipsychotic medications (300 mg/day CPZeq or less) in older Asian patients with schizophrenia and its demographic and clinical correlates.
  18. Xiang YT, Kreyenbuhl J, Dickerson FB, Ungvari GS, Wang CY, Si TM, et al.
    Aust N Z J Psychiatry, 2012 Dec;46(12):1159-64.
    PMID: 22790175 DOI: 10.1177/0004867412453625
    This study examined the prescribing patterns of several first- (FGAs) and second-generation antipsychotic (SGAs) medications administered to older Asian patients with schizophrenia during the period between 2001 and 2009.
  19. Xiang YT, Kreyenbuhl J, Dickerson FB, Ungvari GS, Wang CY, Si TM, et al.
    Int J Clin Pharmacol Ther, 2012 Jul;50(7):500-4.
    PMID: 22541750 DOI: 10.5414/CP201683
    This study surveyed the prescribing patterns of antipsychotic medications in Asian older schizophrenia patients with extrapyramidal side effects (EPS) during the period between 2001 and 2009.
  20. Sim K, Yong KH, Chan YH, Tor PC, Xiang YT, Wang CY, et al.
    Int. J. Neuropsychopharmacol., 2011 Oct;14(9):1157-64.
    PMID: 21557883 DOI: 10.1017/S1461145711000563
    Recent studies indicate relatively high international rates of adjunctive psychotropic medication, including mood stabilizers, for patients with schizophrenia. Since such treatments are little studied in Asia, we examined the frequency of mood-stabilizer use and its clinical correlates among hospitalized Asian patients diagnosed with schizophrenia in 2001-2008. We evaluated usage rates of mood stabilizers with antipsychotic drugs, and associated factors, for in-patients diagnosed with DSM-IV schizophrenia in 2001, 2004 and 2008 in nine Asian regions: China, Hong Kong, India, Korea, Japan, Malaysia, Taiwan, Thailand, and Singapore. Overall, mood stabilizers were given to 20.4% (n=1377/6761) of hospitalized schizophrenia patients, with increased usage over time. Mood-stabilizer use was significantly and independently associated in multivariate logistic modeling with: aggressive behaviour, disorganized speech, year sampled (2008 vs. earlier), multiple hospitalizations, less negative symptoms, younger age, with regional variation (Japan, Hong Kong, Singapore>Taiwan or China). Co-prescription of adjunctive mood stabilizers with antipsychotics for hospitalized Asian schizophrenia patients increased over the past decade, and was associated with specific clinical characteristics. This practice parallels findings in other countries and illustrates ongoing tension between evidence-based practice vs. individualized, empirical treatment of psychotic disorders.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links