MyMedR

Displaying publications 61 - 80 of 268 in total

Abstract:

Sort:

Polymorphisms in the androgen receptor CAG repeat sequence are related to tumour stage but not to ERG or androgen receptor expression in Malaysian men with prostate cancer

Tan JSJ, Ong KC, Ong DBL, Wu YS, Razack A, Kuppusamy S, et al.

Malays J Pathol, 2019 Dec;41(3):243-251.
PMID: 31901908

INTRODUCTION: Polymorphic expression of a CAG repeat sequence in the androgen receptor (AR) gene may influence the activity of the AR and the occurrence of prostate cancer and the TMPRSS2-ERG fusion event. Furthermore, this polymorphism may be responsible for the ethnic variation observed in prostate cancer occurrence and expression of the ERG oncogene. We investigate the expression of AR and ERG in the biopsies of Malaysian men with prostate cancer and in the same patients relate this to the length of the CAG repeat sequence in their AR gene.
MATERIALS AND METHODS: From a PSA screening initiative, 161 men were shown to have elevated PSA levels in their blood and underwent prostatic tissue biopsy. DNA was extracted from the blood, and exon 1 of the AR gene amplified by PCR and sequenced. The number of CAG repeat sequences were counted and compared to the immunohistochemical expression of ERG and AR in the matched tumour biopsies.
RESULTS: Of men with elevated PSA, 89 were diagnosed with prostate cancer, and 72 with benign prostatic hyperplasia (BPH). There was no significant difference in the length of the CAG repeat in men with prostate cancer and BPH. The CAG repeat length was not associated with; age, PSA or tumour grade, though a longer CAG repeat was associated with tumour stage. ERG and AR were expressed in 36% and 86% of the cancers, respectively. There was no significant association between CAG repeat length and ERG or AR expression. However, there was a significant inverse relationship between ERG and AR expression. In addition, a significantly great proportion of Indian men had ERG positive tumours, compared to men of Malay or Chinese descent.
CONCLUSIONS: CAG repeat length is not associated with prostate cancer or expression of ERG or AR. However, ERG appears to be more common in the prostate cancers of Malaysian Indian men than in the prostate cancers of other Malaysian ethnicities and its expression in this study was inversely related to AR expression.
Sedimentation Kinetics of Magnetic Nanoparticle Clusters: Iron Oxide Nanospheres vs Nanorods

Ng WM, Katiyar A, Mathivanan V, Teng XJ, Leong S, Low S, et al.

Langmuir, 2020 May 19;36(19):5085-5095.
PMID: 32338911 DOI: 10.1021/acs.langmuir.0c00135

A detailed study of the sedimentation kinetics of iron oxide nanoparticle (IONP) clusters composed of nanospheres and nanorods is presented. Measurements were performed to determine the absorbance of an IONP suspension undergoing sedimentation over time by using a UV-vis spectrophotometer with simultaneous monitoring of the hydrodynamic diameter of the clusters formed with dynamic light scattering (DLS). Mathematical analysis based on Happel's spherical and cylindrical models was conducted to reveal the relationship between the settling velocity of the IONP clusters and their packing density. For the case of IONP clusters composed of rodlike particles, two distinctive phases of sedimentation were recorded, with the occurrence of rapid sedimentation at the beginning of the process (phase I) followed by a slower settling rate (phase II). In sedimentation phase II, even though the nanorod clusters had a hydrodynamic size of >500 nm, which was much larger than that of the nanosphere clusters (∼200 nm), their settling velocity of 0.0038 mm/min was still slower than that of the nanosphere clusters. Such observations were mainly a result of the packing density differences between the formed clusters; due to the end-to-end particle interactions of nanorods, the nanorod clusters were less tightly packed and more permeable. In addition to the mathematical analysis, quartz crystal microbalance with dissipation (QCM-D) was employed to measure the "softness" of the IONP clusters formed, and this physical property can be further related to their packing density. This study illustrated that for a rapidly aggregating system, such as magnetic IONPs, not only do the particle shape and size uniformity contribute to the physical properties of the particle clusters formed but also the nature of the aggregation, either end-to-end and/or side-to-side, should be carefully considered when designing a colloidally stable IONP suspension.
Low-gradient magnetic separation of magnetic nanoparticles under continuous flow: Experimental study, transport mechanism and mathematical modelling

Tan YW, Leong SS, Lim J, Yeoh WM, Toh PY

Electrophoresis, 2022 Nov;43(21-22):2234-2249.
PMID: 35921231 DOI: 10.1002/elps.202200078

Low-gradient magnetic separation (LGMS) of magnetic nanoparticles (MNPs) has been proven as one of the techniques with great potential for biomedical and environmental applications. Recently, the underlying principle of particle capture by LGMS, through a process known as magnetophoresis, under the influence of hydrodynamic effect has been widely studied and illustrated. Even though the hydrodynamic effect is very substantial for batch processes, its impact on LGMS operated at continuous flow (CF) condition remained largely unknown. Hence, in this study, the dynamical behaviour of LGMS process operated under CF was being studied. First, the LGMS experiments using poly(sodium 4-styrenesulfonate)-functionalized-MNP as modelled particle system were performed through batchwise (BW) and CF modes at different operating conditions. Here BW operation was used as a comparative study to elucidate the transport mechanism of MNP under the similar environment of CF-LGMS process, and it was found out that the convection induced by magnetophoresis (timescale effective is ∼1200 s) is only significant at far-from-magnet region. Hence, it can be deduced that forced convection is more dominant on influencing the transport behaviour of CF-LGMS (with resident time ≤240 s). Moreover, we found that the separation efficiency of CF-LGMS process can be boosted by the higher number of magnets, the higher MNP concentration and the lower flowrate of MNP solution. To better illustrate the underlying dynamical behaviour of LGMS process, a mathematical model was developed to predict its kinetic profile and separation efficiency (with average error of ∼2.6% compared to the experimental results).
Low-Gradient Magnetophoresis of Nanospheres and Nanorods through a Single Layer of Paper

Law JKC, Ng WM, Chong WH, Li Q, Zhang L, Khoerunnisa F, et al.

Langmuir, 2023 Apr 11;39(14):4904-4916.
PMID: 36992604 DOI: 10.1021/acs.langmuir.2c03164

The possible magnetophoretic migration of iron oxide nanoparticles through the cellulosic matrix within a single layer of paper is challenging with its underlying mechanism remained unclear. Even with the recent advancements of theoretical understanding on magnetophoresis, mainly driven by cooperative and hydrodynamics phenomena, the contributions of these two mechanisms on possible penetration of magnetic nanoparticles through cellulosic matrix of paper have yet been proven. Here, by using iron oxide nanoparticles (IONPs), both nanospheres and nanorods, we have investigated the migration kinetics of these nanoparticles through grade 4 Whatman filter paper with a particle retention of 20-25 μm. By performing droplet tracking experiments, the real-time stained area growth of the particle droplet on the filter paper, under the influences of a grade N40 NdFeB magnet, were recorded. Our results show that the spatial and temporal expansion of the IONP stain is biased toward the magnet and such an effect is dependent on (i) particle concentration and (ii) particle shape. The kinetics data were first analyzed by treating it as a radial wicking fluid, and later the IONP distribution within the cellulosic matrix was investigated by optical microscopy. The macroscopic flow front velocities of the stained area ranged from 259 μm/s to 16 040 μm/s. Moreover, the microscopic magnetophoretic velocity of nanorod cluster was also successfully measured as ∼214 μm/s. Findings in this work have indirectly revealed the strong influence of cooperative magnetophoresis and the engineering feasibility of paper-based magnetophoretic technology by taking advantage of magnetoshape anisotropy effect of the particles.
Toxicological and pharmacokinetic analysis at therapeutic dose of SRS27, an investigational anti-asthma agent

Lim JCW, Sagineedu SR, Yong ACH, Sidik SM, Wong WSF, Stanslas J

Naunyn Schmiedebergs Arch Pharmacol, 2021 Jan;394(1):95-105.
PMID: 32840650 DOI: 10.1007/s00210-020-01966-3

SRS27, an andrographolide analogue, had been proven to have therapeutic properties at a dose of 3 mg/kg in both in vitro and in vivo asthma models of our previous study. The present study focuses on the pharmacokinetic and toxicity profile of this compound to provide further evidence for the development of this compound as an anti-asthma agent. A simple pharmacokinetic study was performed in female BALB/c mice to measure blood plasma concentration of the compound at therapeutic dose. At a single dose of 3 mg/kg, SRS27 had a relatively short half-life but was able to achieve a concentration range of 13-19 μM that is related to its in vitro bioactivities. With regard to toxicity profile, SRS27 appears to be safe, as no histopathological changes were observed in the liver, kidneys and ovaries of SRS27-treated female BALB/c mice. In addition, there was no significant change in the mean body weight and organ weight of the animals in the SRS27-treated groups compared with the vehicle-treated control group at the end of the treatment. This fully supports the absence of any significant changes in peripheral blood leukocyte counts of SRS27-treated mice. Rewardingly, this acute toxicity study also revealed that SRS27 has a wide therapeutic window as no toxicity symptoms were detected with a dose up to 60 mg/kg daily when tested for 14 days. These results provide strong justification for further investigation of SRS27 as a potential new anti-asthma agent.
Migration health ethics in Southeast Asia: a scoping review

Ng SH, Kaur S, Cheah PY, Ong ZL, Lim J, Voo TC

Wellcome Open Res, 2023;8:391.
PMID: 38595706 DOI: 10.12688/wellcomeopenres.19572.2

BACKGROUND: Asia hosts the second-largest international migrant population in the world. In Southeast Asia (SEA), key types of migration are labour migration, forced migration, and environmental migration. This scoping review seeks to identify key themes and gaps in current research on the ethics of healthcare for mobile and marginalised populations in SEA, and the ethics of research involving these populations.
METHODS: We performed a scoping review using three broad concepts: population (stateless population, migrants, refugees, asylum seekers, internally displaced people), issues (healthcare and ethics), and context (11 countries in SEA). Three databases (PubMed, CINAHL, and Web of Science) were searched from 2000 until May 2023 over a period of four months (February 2023 to May 2023). Other relevant publications were identified through citation searches, and six bioethics journals were hand searched. All searches were conducted in English, and relevant publications were screened against the inclusion and exclusion criteria. Data were subsequently imported into NVivo 14, and thematic analysis was conducted.
RESULTS: We identified 18 papers with substantial bioethical analysis. Ethical concepts that guide the analysis were 'capability, agency, dignity', 'vulnerability', 'precarity, complicity, and structural violence' (n=7). Ethical issues were discussed from the perspective of research ethics (n=9), clinical ethics (n=1) and public health ethics (n=1). All publications are from researchers based in Singapore, Thailand, and Malaysia. Research gaps identified include the need for more research involving migrant children, research from migrant-sending countries, studies on quality of migrant healthcare, participatory health research, and research with internal migrants.
CONCLUSIONS: More empirical research is necessary to better understand the ethical issues that exist in the domains of research, clinical care, and public health. Critical examination of the interplay between migration, health and ethics with consideration of the diverse factors and contexts involved is crucial for the advancement of migration health ethics in SEA.
Fulltext Ethnicity is an independent determinant of age-specific PSA level: findings from a multiethnic Asian setting

Lim J, Bhoo-Pathy N, Sothilingam S, Malek R, Sundram M, Hisham Bahadzor B, et al.

PLoS One, 2014;9(8):e104917.
PMID: 25111507 DOI: 10.1371/journal.pone.0104917

OBJECTIVES: To study the baseline PSA profile and determine the factors influencing the PSA levels within a multiethnic Asian setting.
MATERIALS AND METHODS: We conducted a cross-sectional study of 1054 men with no clinical evidence of prostate cancer, prostate surgery or 5α-reductase inhibitor treatment of known prostate conditions. The serum PSA concentration of each subject was assayed. Potential factors associated with PSA level including age, ethnicity, height, weight, family history of prostate cancer, lower urinary tract voiding symptoms (LUTS), prostate volume and digital rectal examination (DRE) were evaluated using univariable and multivariable analysis.
RESULTS: There were 38 men (3.6%) found to have a PSA level above 4 ng/ml and 1016 (96.4%) with a healthy PSA (≤4 ng/ml). The median PSA level of Malay, Chinese and Indian men was 1.00 ng/ml, 1.16 ng/ml and 0.83 ng/ml, respectively. Indians had a relatively lower median PSA level and prostate volume than Malays and Chinese, who shared a comparable median PSA value across all 10-years age groups. The PSA density was fairly similar amongst all ethnicities. Further analysis showed that ethnicity, weight and prostate volume were independent factors associated with age specific PSA level in the multivariable analysis (p<0.05).
CONCLUSION: These findings support the concept that the baseline PSA level varies between different ethnicities across all age groups. In addition to age and prostate volume, ethnicity may also need to be taken into account when investigating serum PSA concentrations in the multiethnic Asian population.
Coronary artery calcification across ethnic groups in Singapore

Chia PL, Earnest A, Lee R, Lim J, Wong CP, Chia YW, et al.

Ann Acad Med Singap, 2013 Sep;42(9):432-6.
PMID: 24162317

INTRODUCTION: In Singapore, the age-standardised event rates of myocardial infarction (MI) are 2- and 3-fold higher for Malays and Indians respectively compared to the Chinese. The objectives of this study were to determine the prevalence and quantity of coronary artery calcification (CAC) and non-calcified plaques across these 3 ethnic groups.
MATERIALS AND METHODS: This was a retrospective descriptive study. We identified 1041 patients (810 Chinese, 139 Malays, 92 Indians) without previous history of cardiovascular disease who underwent cardiac computed tomography for atypical chest pain evaluation. A cardiologist, who was blinded to the patients' clinical demographics, reviewed all scans. We retrospectively analysed all their case records.
RESULTS: Overall, Malays were most likely to be active smokers (P = 0.02), Indians had the highest prevalence of diabetes mellitus (P = 0.01) and Chinese had the highest mean age (P <0.0001). The overall prevalence of patients with non-calcified plaques as the only manifestation of sub-clinical coronary artery disease was 2.1%. There was no significant difference in the prevalence of CAC, mean CAC score or prevalence of non-calcified plaques among the 3 ethnic groups. Active smoking, age and hypertension were independent predictors of CAC. Non-calcified plaques were positively associated with male gender, age, dyslipidaemia and diabetes mellitus.
CONCLUSION: The higher MI rates in Malays and Indians in Singapore cannot be explained by any difference in CAC or non-calcified plaque. More research with prospective follow-up of larger patient populations is necessary to establish if ethnic-specific calibration of CAC measures is needed to adjust for differences among ethnic groups.
A semisynthetic diterpenoid lactone inhibits NF-κB signalling to ameliorate inflammation and airway hyperresponsiveness in a mouse asthma model

Lim JC, Goh FY, Sagineedu SR, Yong AC, Sidik SM, Lajis NH, et al.

Toxicol Appl Pharmacol, 2016 07 01;302:10-22.
PMID: 27089844 DOI: 10.1016/j.taap.2016.04.004

Andrographolide (AGP) and 14-deoxy-11,12-didehydroandrographolide (DDAG), two main diterpenoid constituents of Andrographis paniculata were previously shown to ameliorate asthmatic symptoms in a mouse model. However, due to inadequacies of both compounds in terms of drug-likeness, DDAG analogues were semisynthesised for assessment of their anti-asthma activity. A selected analogue, 3,19-diacetyl-14-deoxy-11,12-didehydroandrographolide (SRS27), was tested for inhibitory activity of NF-κB activation in TNF-α-induced A549 cells and was subsequently evaluated in a mouse model of ovalbumin (OVA)-induced asthma. Female BALB/c mice, 6-8weeks old were sensitized on days 0 and 14, and challenged on days 22, 23 and 24 with OVA. Compound or vehicle (3% dimethyl sulfoxide) was administered intraperitoneally 1h before and 11h after each OVA aerosol challenge. On day 25, pulmonary eosinophilia, airway hyperresponsiveness, mucus hypersecretion, inflammatory cytokines such as IL-4, -5 and -13 in BAL fluid, gene expression of inflammatory mediators such as 5-LOX, E-selectin, VCAM-1, CCL5, TNF-α, AMCase, Ym2, YKL-40, Muc5ac, CCL2 and iNOS in animal lung tissues, and serum IgE were determined. SRS27 at 30μM was found to suppress NF-κB nuclear translocation in A549 cells. In the ovalbumin-induced mouse asthma model, SRS27 at 3mg/kg displayed a substantial decrease in pulmonary eosinophilia, BAL fluid inflammatory cytokines level, serum IgE production, mucus hypersecretion and gene expression of inflammatory mediators in lung tissues. SRS27 is the first known DDAG analogue effective in ameliorating inflammation and airway hyperresponsiveness in the ovalbumin-induced mouse asthma model.
Fulltext Mesenchymal Stromal Cells from the Maternal Segment of Human Umbilical Cord is Ideal for Bone Regeneration in Allogenic Setting

Lim J, Razi ZRM, Law JX, Nawi AM, Idrus RBH, Chin TG, et al.

Tissue Eng Regen Med, 2018 Feb;15(1):75-87.
PMID: 30603536 DOI: 10.1007/s13770-017-0086-6

Umbilical cord (UC) is a discarded product from the operating theatre and a ready source of mesenchymal stromal cells (MSCs). MSCs from UC express both embryonic and adult mesenchymal stem cell markers and are known to be hypoimmunogenic and non-tumorigenic and thus suitable for allogeneic cell transplantation. Our study aimed to determine the degree of immunotolerance and bone-forming capacity of osteodifferentiated human Wharton's jelly-derived mesenchymal stromal cells (hWJ-MSCs) from different segments of UC in an allogenic setting. UCs were obtained from healthy donors delivering a full-term infant by elective Caesarean section. hWJ-MSCs were isolated from 3 cm length segment from the maternal and foetal ends of UCs. Three-dimensional fibrin constructs were formed and implanted intramuscularly into immunocompetent mice. The mice were implanted with 1) fibrin construct with maternal hWJ-MSCs, 2) fibrin construct with foetal hWJ-MSCs, or 3) fibrin without cells; the control group received sham surgery. After 1 month, the lymphoid organs were analysed to determine the degree of immune rejection and bone constructs were analysed to determine the amount of bone formed. A pronounced immune reaction was noted in the fibrin group. The maternal segment constructs demonstrated greater osteogenesis than the foetal segment constructs. Both maternal and foetal segment constructs caused minimal immune reaction and thus appear to be safe for allogeneic bone transplant. The suppression of inflammation may be a result of increased anti-inflammatory cytokine production mediated by the hWJ-MSC. In summary, this study demonstrates the feasibility of using bone constructs derived from hWJ-MSCs in an allogenic setting.
A New Simplified Visual Assessment Tool Describing Facial Morphotypes Observed and Desired in Asian Populations

Corduff N, Chao YY, Lam SC, Lim J, Lim TS, Lohia K, et al.

J Clin Aesthet Dermatol, 2020 Apr;13(4):23-34.
PMID: 33144908

OBJECTIVE: A group of established aesthetic physicians sought to develop treatment guidelines for assessing Asian face morphologies that reflect accurate and current beauty standards across Asia. DESIGN: Physicians completed surveys, debated, and voted on their clinical strategies and developed an alternative simplified visual tool of assessment (SVAT) that discerns between country variations in genetic and ideal morphotypes. SETTING: Electronic and paper surveys were followed by consensus debates and voting. PARTICIPANTS: Established aesthetic physicians practicing regularly on Asian patients. MEAUSUREMENTS: A clinically applicable SVAT was developed, which considered facial index, mid-face projection, upper and lower face shape, submalar contour, nose length and dorsal height, eye shape and brow shape, proportion of lips-to-lower face and ratio of upper-to-lower lip, and chin shape. RESULTS: For facial shape change, physicians always assessed the horizontal thirds, facial symmetry, and lip-chin complex profile, and also analyzed overall face shapes and Ogee curves. Criteria for creating oval-shaped faces was also defined and included treating indications, such as loss of angularity and bilateral masseter muscle hypertrophy, narrow jawlines, and longer and wider foreheads. Critical differences and similarities in country-specific aesthetic preferences, treatment requests, and considerations or strategies were uncovered, including the inadequacy of assessing overall peripheral facial shapes. CONCLUSION: This consensus establishes the assessment and treatment criteria for achieving ideal shapes for Asian patients. Specific descriptors are affected by variations; therefore, we present the visual criteria for Asian facial morphotypes. We hope that physicians new to treating Asian patients can use this clinical information to improve their practice.
Fulltext Predictive factors of prostate cancer diagnosis with PSA 4.0-10.0 ng/ml in a multi-ethnic Asian population, Malaysia

Yii RSL, Lim J, Sothilingam S, Yeoh WS, Fadzli AN, Ong TA, et al.

Asian J Surg, 2020 Jan;43(1):87-94.
PMID: 30962017 DOI: 10.1016/j.asjsur.2019.02.014

OBJECTIVES: To identify the associated factors determining prostate cancer detection using transrectal ultrasound (TRUS)-guided prostate biopsy, within a multi-ethnic Malaysian population with prostate specific antigen (PSA) between 4.0 and 10.0 ng/ml.
METHODS: Study subjects included men with initial PSA between 4.0 and 10.0 ng/ml that have undergone 12-core TRUS-guided prostate biopsy between 2009 and 2016. The prostate cancer detection rate was calculated, while potential factors associated with detection were investigated via univariable and multivariable analysis.
RESULTS: A total of 617 men from a multi-ethnic background encompassing Chinese (63.5%), Malay (23.1%) and Indian (13.3%) were studied. The overall cancer detection rate was 14.3% (88/617), which included cancers detected at biopsy 1 (first biopsy), biopsy 2 (second biopsy with previous negative biopsy) and biopsy ≥ 3 (third or more biopsies with prior negative biopsies). Indian men displayed higher detection rate (23.2%) and increased risk of prostate cancer development (OR 1.85, 95% CI 1.03-3.32, p
The Transport Behavior of a Biflagellated Microswimmer before and after Cargo Loading

Teng XJ, Ng WM, Chong WH, Chan DJC, Mohamud R, Ooi BS, et al.

Langmuir, 2021 08 03;37(30):9192-9201.
PMID: 34255525 DOI: 10.1021/acs.langmuir.1c01345

The changes in the transport behavior of a microswimmer before and after cargo loading are crucial to understanding and control of the motion of a biohybrid microbot. In this work, we show the change in swimming behavior of biflagellated microalgae Chlamydomonas reinhardtii picking up a 4.5 μm polystyrene microbead upon collision. The microswimmer changed from linear forward motion into helical motion upon the attachment of the cargo and swam with a decreased swimming velocity. We revealed the helical motion of the microswimmer upon cargo loading due to suppression of flagella by image analysis of magnified time-lapse images of C. reinhardtii with one microbead attached at the anterior end (between the flagella). Furthered suppression on the flagellum imposed by the loading of the second cargo has led to increased oscillation per displacement traveled and decreased swimming velocity. Moreover, the microswimmer with a microbead attached at the posterior end swam with swimming velocity close to free swimming microalgae and did not exhibit helical swimming behavior. The experimental results and analysis showed that the loading location of the cargo has a great influence over the swimming behavior of the microswimmer. Furthermore, the work balance calculation and mathematical analysis based on Lighthill's model are well consistent with our experimental findings.
A Novel Calculator for Estimating Prostate Volume in Daily Urology Services

Lim J, Rampal S, Razack AHA, Malek R, Sundram M, Nasuha NA, et al.

Urology, 2018 Aug;118:145-151.
PMID: 29746873 DOI: 10.1016/j.urology.2018.02.055

OBJECTIVES: To develop a simple prostate volume (PV) calculator that can aid in managing patients with lower urinary tract symptoms (LUTS) secondary to benign prostatic enlargement at daily urology services in developing Asian countries.
MATERIALS AND METHODS: We conducted a cross-sectional study of men aged above 40 years with no history of prostate cancer, prostate surgery, or 5α-reductase inhibitor treatment. Serum prostate-specific antigen (PSA) and total PV were measured in each subject. Potential sociodemographic and clinical variables including age, weight, comorbidities, and International Prostate Symptom Score (IPSS) were collected. Of 1034 subjects, 837 were used in building the PV calculator using regression analysis. The remaining 1/5 (n = 197) was used for model validation.
RESULTS: There were 1034 multiethnic Asian men (Chinese 52.9%, Malay 35.4%, and Indian 11.7%) with mean age of 60 ± 7.6 years. Average PV was 29.4 ± 13.0 mL while the overall mean of PSA was 1.7 ± 1.7 ng/mL. We identified age, IPSS, weight, and PSA (all P
Artificial Magnetotaxis of Microbot: Magnetophoresis versus Self-Swimming

Ng WM, Che HX, Guo C, Liu C, Low SC, Chieh Chan DJ, et al.

Langmuir, 2018 07 10;34(27):7971-7980.
PMID: 29882671 DOI: 10.1021/acs.langmuir.8b01210

An artificial magnetotactic microbot was created by integrating the microalgal cell with magnetic microbead for its potential application as biomotor in microscale environment. Here, we demonstrate the remote magnetotactic control of the microbot under a low gradient magnetic field (<100 T/m). We characterize the kinematic behavior of the microbots carrying magnetic microbeads of two different sizes, with diameter of 2 and 4.5 μm, in the absence and presence of magnetic field. In the absence of magnetic field, we observed the microbot showed a helical motion as a result of the misalignment between the thrust force and the symmetry axis after the attachment. The microbot bound with a larger magnetic microbead moved with higher translational velocity but rotated slower about its axis of rotation. The viscous force was balanced by the thrust force of the microbot, resulting in a randomized swimming behavior of the microbot at its terminal velocity. Meanwhile, under the influence of a low gradient magnetic field, we demonstrated that the directional control of the microbot was based on following principles: (1) magnetophoretic force was insignificant on influencing its perpendicular motion and (2) its parallel motion was dependent on both self-swimming and magnetophoresis, in which this cooperative effect was a function of separation distance from the magnet. As the microbot approached the magnet, the magnetophoretic force suppressed its self-swimming behavior, leading to a positive magnetotaxis of the microbot toward the source of magnetic field. Our experimental results and kinematic analysis revealed the contribution of mass density variation of particle-and-cell system on influencing its dynamical behavior.
Fulltext Factors Determining the Increased Risk of Falls in Individuals With Knee Pain in the Malaysian Elders Longitudinal Research (MELoR) Study

Mat S, Razack AH, Lim J, Khong SY, Kamaruzzaman SB, Chin AV, et al.

Front Med (Lausanne), 2019;6:277.
PMID: 31850355 DOI: 10.3389/fmed.2019.00277

Objectives: While the negative impact of falls in older persons has been recognized, the association between knee pains and falls remains inconclusive due to underreporting and undertreatment of knee pain. This study was conducted to evaluate the relationship between knee pain and knee pain severity with falls risk and to further determine factors which influence this potential relationship. Design: This was cross-sectional study from the Malaysian Elders Longitudinal Research (MELoR) study. Setting: Urban community dwellers in a middle-income South East Asian country. Participants: One thousand two hundred twelve of a representative sample of community dwelling older persons aged 55 years and older. Outcome measures: Falls in the preceding 12 months and knee pain were collected during a home-based computer-assisted interview. Physical and functional performance were measured using the Timed Up and Go test and the Katz and Lawton scales, respectively. Psychological status was determined using the Depression Anxiety and Stress Scale (DASS-21). Results: Of the 1,212 participants included in this analysis, knee pain was present in 402 (33.17%) individuals (124 (30.85%) mild, 210 (52.24%) moderate, 68 (16.92%) severe). The presence of knee pain was associated with increased risk of falls [odds Ratio, OR(95% confidence interval, CI): 1.81 (1.37-2.38)]. Severe knee pain was an independent predictor for falls after adjustment for functional impairment and psychological status. Mild, moderate, and severe knee pain had a specific indirect effect on falls through reducing functional impairment, which in turn increases their psychological concern. Conclusion: Future studies should explore this relationship prospectively and evaluate whether interventions which alleviate psychological concerns and improve function will reduce falls risk in those with mild to moderate knee pain.
A study of hospitalized COVID-19 patients with AKI in a setting of multiracial developing country

Ooi SH, Ng KP, Sthaneshwar P, Lim SK, Khor PY, Lim JY, et al.

BMC Nephrol, 2024 Apr 05;25(1):122.
PMID: 38580977 DOI: 10.1186/s12882-024-03498-x

BACKGROUND: The commonest indication for hospitalization in COVID-19 patients is hypoxemia or severe respiratory symptoms. However, COVID-19 disease may result in extrapulmonary complications including kidney-related pathology. The reported incidence of renal involvement related to COVID infection varies based on geographical location.
OBJECTIVE: This study aimed to assess the incidence rate of AKI in hospitalized COVID-19 patients and identify risk factors and prognostic predictors.
METHOD: In this retrospective study, we recruited hospitalized COVID-19 patients from January 2021 until June 2021 at the University Malaya Medical Center. The inclusion criteria were hospitalized for ≥ 48 h with confirmed COVID-19 infection and at least 18 years old. Patient demographic and clinical data were collected from electronic medical records. The staging of AKI was based on criteria as per KDIGO guidelines.
RESULTS: One thousand five hundred twenty-nine COVID patients fulfilled the inclusion criteria with a male-to-female ratio of 759 (49.6%) to 770 (50.3%). The median age was 55 (IQR: 36-66). 500 patients (32.7%) had diabetes, 621 (40.6%) had hypertension, and 5.6% (n = 85) had pre-existing chronic kidney disease (CKD). The incidence rate of AKI was 21.1% (n = 323). The percentage of COVID patients in different AKI stages of 1,2 and 3 were 16.3%, 2.1%, and 2.7%, respectively. Fifteen hospitalized patients (0.98%) required renal replacement therapy. 58.8% (n = 190) of AKI group had complete recovery of kidney function. Demographic factors included age (p
Progress toward universal health coverage in ASEAN

Van Minh H, Pocock NS, Chaiyakunapruk N, Chhorvann C, Duc HA, Hanvoravongchai P, et al.

Glob Health Action, 2014 Dec;7(1):25856.
PMID: 28672540 DOI: 10.3402/gha.v7.25856

Background The Association of Southeast Asian Nations (ASEAN) is characterized by much diversity in terms of geography, society, economic development, and health outcomes. The health systems as well as healthcare structure and provisions vary considerably. Consequently, the progress toward Universal Health Coverage (UHC) in these countries also varies. This paper aims to describe the progress toward UHC in the ASEAN countries and discuss how regional integration could influence UHC. Design Data reported in this paper were obtained from published literature, reports, and gray literature available in the ASEAN countries. We used both online and manual search methods to gather the information and 'snowball' further data. Results We found that, in general, ASEAN countries have made good progress toward UHC, partly due to relatively sustained political commitments to endorse UHC in these countries. However, all the countries in ASEAN are facing several common barriers to achieving UHC, namely 1) financial constraints, including low levels of overall and government spending on health; 2) supply side constraints, including inadequate numbers and densities of health workers; and 3) the ongoing epidemiological transition at different stages characterized by increasing burdens of non-communicable diseases, persisting infectious diseases, and reemergence of potentially pandemic infectious diseases. The ASEAN Economic Community's (AEC) goal of regional economic integration and a single market by 2015 presents both opportunities and challenges for UHC. Healthcare services have become more available but health and healthcare inequities will likely worsen as better-off citizens of member states might receive more benefits from the liberalization of trade policy in health, either via regional outmigration of health workers or intra-country health worker movement toward private hospitals, which tend to be located in urban areas. For ASEAN countries, UHC should be explicitly considered to mitigate deleterious effects of economic integration. Political commitments to safeguard health budgets and increase health spending will be necessary given liberalization's risks to health equity as well as migration and population aging which will increase demand on health systems. There is potential to organize select health services regionally to improve further efficiency. Conclusions We believe that ASEAN has significant potential to become a force for better health in the region. We hope that all ASEAN citizens can enjoy higher health and safety standards, comprehensive social protection, and improved health status. We believe economic and other integration efforts can further these aspirations.
Fulltext Cardiovascular Risk Factors and Ethnicity Are Independent Factors Associated with Lower Urinary Tract Symptoms

Lim J, Bhoo-Pathy N, Sothilingam S, Malek R, Sundram M, Tan GH, et al.

PLoS One, 2015;10(6):e0130820.
PMID: 26098884 DOI: 10.1371/journal.pone.0130820

To determine the lower urinary tract symptoms (LUTS) profile and factors affecting its degree of severity including cardiovascular risk profile, age, ethnicity, education level and prostate volume in a multiethnic Asian setting.
Fulltext The different fates of two Asian horseshoe crab species with different dispersal abilities

Tang Q, Shingate P, Wardiatno Y, John A, Tay BH, Tay YC, et al.

Evol Appl, 2021 Aug;14(8):2124-2133.
PMID: 34429753 DOI: 10.1111/eva.13271

Impending anthropogenic climate change will severely impact coastal organisms at unprecedented speed. Knowledge on organisms' evolutionary responses to past sea-level fluctuations and estimation of their evolutionary potential is therefore indispensable in efforts to mitigate the effects of future climate change. We sampled tens of thousands of genomic markers of ~300 individuals in two of the four extant horseshoe crab species across the complex archipelagic Singapore Straits. Carcinoscorpius rotundicauda Latreille, a less mobile mangrove species, has finer population structure and lower genetic diversity compared with the dispersive deep-sea Tachypleus gigas Müller. Even though the source populations of both species during the last glacial maximum exhibited comparable effective population sizes, the less dispersive C. rotundicauda seems to lose genetic diversity much more quickly because of population fragmentation. Contra previous studies' results, we predict that the more commonly sighted C. rotundicauda faces a more uncertain conservation plight, with a continuing loss in evolutionary potential and higher vulnerability to future climate change. Our study provides important genomic baseline data for the redirection of conservation measures in the face of climate change and can be used as a blueprint for assessment and mitigation of the adverse effects of impending sea-level rise in other systems.

Filters

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

External Links