Displaying publications 21 - 40 of 268 in total

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  1. Electrosteric stabilization and its role in cooperative magnetophoresis of colloidal magnetic nanoparticles
    Yeap SP, Ahmad AL, Ooi BS, Lim J
    Langmuir, 2012 Oct 23;28(42):14878-91.
    PMID: 23025323 DOI: 10.1021/la303169g
    A detailed study on the conflicting role that colloid stability plays in magnetophoresis is presented. Magnetic iron oxide particles (MIOPs) that were sterically stabilized via surface modification with poly(sodium 4-styrene sulfonate) of different molecular weights (i.e., 70 and 1000 kDa) were employed as our model system. Both sedimentation kinetics and quartz crystal microbalance with dissipation (QCM-D) measurements suggested that PSS 70 kDa is a better stabilizer as compared to PSS 1000 kDa. This observation is mostly attributed to the bridging flocculation of PSS 1000 kDa decorated MIOPs originated from the extended polymeric conformation layer. Later, a lab-scale high gradient magnetic separation (HGMS) device was designed to study the magnetophoretic collection of MIOPs. Our experimental results revealed that the more colloidally stable the MIOP suspension is, the harder it is to be magnetically isolated by HGMS. At 50 mg/L, naked MIOPs without coating can be easily captured by HGMS at separation efficiency up to 96.9 ± 2.6%. However, the degree of separation dropped quite drastically to 83.1 ± 1.2% and 67.7 ± 4.6%, for MIOPs with PSS 1000k and PSS 70k coating, respectively. This observation clearly implies that polyelectrolyte coating that was usually employed to electrosterically stabilize a colloidal system in turn compromises the magnetic isolation efficiency. By artificially destroying the colloidal stability of the MIOPs with ionic strength increment, the ability for HGMS to recover the most stable suspension (i.e., PSS 70k-coated MIOPs) increased to >86% at 100 mM monovalent ion (Na(+)) or at 10 mM divalent ion (Ca(2+)). This observation has verified the conflicting role of colloidal stability in magnetophoretic separation.
  2. Fulltext Understanding the dimorphic lifestyles of human gastric pathogen Helicobacter pylori using the SWATH-based proteomics approach
    Loke MF, Ng CG, Vilashni Y, Lim J, Ho B
    Sci Rep, 2016 05 25;6:26784.
    PMID: 27222005 DOI: 10.1038/srep26784
    Helicobacter pylori may reside in the human stomach as two morphological forms: the culturable spiral form and the viable but non-culturable (VBNC) coccoid form. This bacterium transforms from spiral to coccoid under in vitro suboptimal conditions. However, both spiral and coccoid have demonstrated its infectivity in laboratory animals, suggesting that coccoid may potentially be involved in the transmission of H. pylori. To determine the relevance of the coccoid form in viability and infectivity, we compared the protein profiles of H. pylori coccoids obtained from prolonged (3-month-old) culture with that of 3-day-old spirals of two H. pylori standard strains using SWATH (Sequential Window Acquisition of all Theoretical mass spectra)-based approach. The protein profiles reveal that the coccoids retained basal level of metabolic proteins and also high level of proteins that participate in DNA replication, cell division and biosynthesis demonstrating that coccoids are viable. Most interestingly, these data also indicate that the H. pylori coccoids possess higher level of proteins that are involved in virulence and carcinogenesis than their spiral counterparts. Taken together, these findings have important implications in the understanding on the pathogenesis of H. pylori-induced gastroduodenal diseases, as well as the probable transmission mode of this bacterium.
  3. Fulltext A comparison between the pregnancy outcome of women with gestation diabetes treated with glibenclamide and those treated with insulin
    Lim JMH, Tayob Y, O'Brien PM, Shaw RW
    Med J Malaysia, 1997 Dec;52(4):377-81.
    PMID: 10968114
    The pregnancy outcome of 33 women with gestational diabetes who were treated with glibenclamide and changed to insulin if glibenclamide failed, were compared with the pregnancy outcome of 21 women with gestational diabetes treated conventionally with insulin. The pregnancy outcome, with regard to the overall glycaemic control, rates of preterm labour, neonatal hypoglycaemia, fetal macrosomia, perinatal morbidity and mortality, were not statistically different between the two treatment groups. The limited number of women studied, and the non-random allocation of these women to each treatment group however, could have influenced these results. There were a few observed differences in the pregnancy outcome between the two treatment groups, which although were not statistically significant, caused some concern. In particular we noted an increased rate of fetal macrosomia in the glibenclamide treated group, which in theory could have been drug mediated.
  4. Fulltext Stroke audit
    Chen RYT, Lim JKH, Chuo AML
    Med J Malaysia, 2003 Aug;58(3):330-6.
    PMID: 14750371
    Medical audit is vital to ensure continuous quality assurance and quality improvements. We did a retrospective study to ascertain the adequacy of clinical documentation and the factors hindering early discharge after an acute stroke in a restructured hospital. The medical records of all patients with acute stroke who died or were discharged from a restructured hospital in Singapore in January and February 1999 were reviewed retrospectively. Demographic data and the presence or absence of clinical documentation were noted. Factors hindering the discharge of patients at Day 5, Day 10 of stroke and at final discharge were noted and classified into: stroke-related, complications of stroke, medical-related and social factors. There were 101 patients in the study cohort, 55 males (54.5%) and 46 females (45.5%). The mean age was 67.9 years (SD 12.3). Documentation in Barthel scores (0%), presence of depression (0%), mental scores (1.0%), visual problems (10.0%), bladder continence (39.6%), admission functional status (37.6%) and dysphagia (52.5%) were deficient. The mean length of stay (LOS) was 13.0 (SD 14.2) days. The main factor hindering discharge at Day 5 (90.4%), Day 10 (95.2%) and at final discharge (82.1%) was stroke-related problems. Poor function (60.3%) and dysphagia (15.8%) were the 2 most common stroke-related problems hindering final discharge. Complications of stroke, medical-related problems and social reasons hindered final discharge in 10.8%, 17.8% and 2.9% of patients respectively. This audit revealed inadequacy in clinical documentation in patients with acute stroke. The main hindrance to final discharge of patients was stroke-related problems. The 2 most important stroke-related problems were poor function and dysphagia.
  5. Fulltext Development of multi-epitope peptide-based vaccines against SARS-CoV-2
    Lim HX, Lim J, Jazayeri SD, Poppema S, Poh CL
    Biomed J, 2021 03;44(1):18-30.
    PMID: 33727051 DOI: 10.1016/j.bj.2020.09.005
    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic involving so far more than 22 million infections and 776,157 deaths. Effective vaccines are urgently needed to prevent SARS-CoV-2 infections. No vaccines have yet been approved for licensure by regulatory agencies. Even though host immune responses to SARS-CoV-2 infections are beginning to be unravelled, effective clearance of virus will depend on both humoral and cellular immunity. Additionally, the presence of Spike (S)-glycoprotein reactive CD4+ T-cells in the majority of convalescent patients is consistent with its significant role in stimulating B and CD8+ T-cells. The search for immunodominant epitopes relies on experimental evaluation of peptides representing the epitopes from overlapping peptide libraries which can be costly and labor-intensive. Recent advancements in B- and T-cell epitope predictions by bioinformatic analysis have led to epitope identifications. Assessing which peptide epitope can induce potent neutralizing antibodies and robust T-cell responses is a prerequisite for the selection of effective epitopes to be incorporated in peptide-based vaccines. This review discusses the roles of B- and T-cells in SARS-CoV-2 infections and experimental validations for the selection of B-, CD4+ and CD8+ T-cell epitopes which could lead to the construction of a multi-epitope peptide vaccine. Peptide-based vaccines are known for their low immunogenicity which could be overcome by incorporating immunostimulatory adjuvants and nanoparticles such as Poly Lactic-co-Glycolic Acid (PLGA) or chitosan.
  6. Fulltext COVID-19 Vaccine Prioritisation for Medical Students: The Forgotten Cohort?
    Lim JS, Au Yong TPT, Boon CS, Boon IS
    Clin Oncol (R Coll Radiol), 2021 08;33(8):e359.
    PMID: 33752932 DOI: 10.1016/j.clon.2021.02.013
  7. Health-care providers' perceptions, attitudes towards and recommendation practice of cervical cancer screening
    Hweissa NA, Lim JN, Su TT
    Eur J Cancer Care (Engl), 2016 Sep;25(5):864-70.
    PMID: 27350095 DOI: 10.1111/ecc.12537
    In Libya, cervical cancer is ranked third as the most frequent cancer among women with early diagnosis being shown to reduce morbidity and mortality. Health-care providers can influence women's screening behaviours, and their lack of recommendations for screening can be one of the barriers that affect women's participation in screening programmes. This study aims to assess the health-care provider's perception around cervical cancer screening. In-depth, face-to-face interviews were conducted with 16 health-care providers, from both public and private sectors in Az-Zawiya city, Libya, between February and July of 2014. The interviews were recorded and transcribed, then analysed using thematic analysis. Our findings suggest that health-care providers did not provide sufficient information regarding cervical cancer screening for women who attend health-care facilities. The results highlight the role played by health-care professionals in motivating women to attend cervical cancer screening programs, and the need for health education of health-care providers to offer a precious advice regarding the screening. On the other hand, health-care providers highlighted that implementation of reminding system of cervical cancer screening will support them to improve screening attendance. In addition, health-care providers stressed the necessity for educational and awareness campaigns of cervical cancer screening among Libyan women.
  8. Fulltext Expression of osteopontin, matrix metalloproteinase-2 and -9 proteins in vascular instability in brain arteriovenous malformation
    Anbarasen L, Lim J, Rajandram R, Mun KS, Sia SF
    PeerJ, 2019;7:e7058.
    PMID: 31275742 DOI: 10.7717/peerj.7058
    Background: Matrix metalloproteinase (MMP)-2 and -9 are Osteopontin (OPN) dependent molecules implicated in the destabilization of blood vessels. OPN and MMPs have been studied in brain arteriovenous malformation (BAVM) patients' tissues and blood samples before intervention. In this study, we compared the serum level of these markers before and after treatment, as well as assessed their protein expressions in BAVM tissues to evaluate their roles in this disease.

    Methodology: Serum samples from six BAVM patients and three control subjects were analyzed using enzyme-linked immunoabsorbent assay (ELISA) for OPN. A total of 10 BAVM patients and five control subjects were analyzed using Multiplex ELISA for MMPs. A total of 16 BAVM tissue samples and two normal brain tissue samples were analyzed using immunohistochemistry.

    Result: MMP-2 and -9 were significantly higher in the serum of BAVM patients before and after treatment than in control patients. There were no significant differences of OPN and MMP-9 serum level in BAVM patients before and after treatment. MMP-2 showed a significant elevation after the treatment. Expression of OPN, MMP-2 and -9 proteins were seen in endothelial cells, perivascular cells and brain parenchyma of BAVM tissues.

    Conclusion: Findings revealed that the level of MMP-2 and -9 in the serum correlated well with the expression in BAVM tissues in several cases. Knockdown studies will be required to determine the relationships and mechanisms of action of these markers in the near future. In addition, studies will be required to investigate the expression of these markers' potential applications as primary medical therapy targets for BAVM patients.

  9. Fulltext Cutaneous manifestation mimicking Stevens-Johnson syndrome in a critically ill patient: looks similar but totally different
    Lim JA, Chong SE, Zainal Abidin H, Hassan MH
    Hong Kong Med J, 2017 12;23(6):653.e3-4.
    PMID: 29226836 DOI: 10.12809/hkmj165051
  10. Novel hormonal therapies in the management of advanced prostate cancer: extrapolating Asian findings to Southeast Asia
    Ong TA, Saad M, Lim J, Lee HH
    BMC Urol, 2023 Jan 06;23(1):4.
    PMID: 36609251 DOI: 10.1186/s12894-022-01156-8
    There is a paucity of information on the use of novel hormonal agents in Southeast Asian patients. We reviewed the clinical roles of novel hormonal therapy (NHT), namely abiraterone acetate (AA), enzalutamide, apalutamide and darolutamide, in the management of advanced prostate cancer, and data on its use in Asian patients, in order to extrapolate these findings to the Southeast Asian patient population. There are some differences in the molecular features between the NHTs, which influenced their respective permeabilities through the blood-brain barrier. The Asian sub-analyses of the landmark studies of each NHT were limited. The primary endpoints of the Asian sub-analyses generally reflect the efficacy outcomes of the respective landmark study. Hypertension, fatigue, musculoskeletal disorders, rash, and hot flushes were among the common toxicities observed in Asian patients. Real-world data on AA in the Asian setting is favourable, but data is limited for enzalutamide, apalutamide and darolutamide. Based on the sub-analyses and real-world data, the efficacy and safety of NHTs in the Asian patients showed a similar trend to the respective landmark studies. The lack of clinical trials in the Southeast Asian region hampers the ability to make a robust conclusion on any specific efficacy or safety differences that may be present; clinicians must assume that the broader Asian sub-analyses and real-world data reflects Southeast Asian patients' outcomes.
  11. Nonhypercholesterolemic effects of a palm-oil diet in Malaysian volunteers
    Ng TK, Hassan K, Lim JB, Lye MS, Ishak R
    Am J Clin Nutr, 1991 04;53(4 Suppl):1015S-1020S.
    PMID: 2012009 DOI: 10.1093/ajcn/53.4.1015S
    The effects on serum lipids of diets prepared with palm olein, corn oil, and coconut oil supplying approximately 75% of the fat calories were compared in three matched groups of healthy volunteers (61 males, 22 females, aged 20-34 y). Group I received a coconut-palm-coconut dietary sequence; group II, coconut-corn-coconut; and group III, coconut oil during all three 5-wk dietary periods. Compared with entry-level values, coconut oil raised the serum total cholesterol concentration greater than 10% in all three groups. Subsequent feeding of palm olein or corn oil significantly reduced the total cholesterol (-19%, -36%), the LDL cholesterol (-20%, -42%%) and the HDL cholesterol (-20%, -26%) concentrations, respectively. Whereas the entry level of the ratio of LDL to HDL was not appreciably altered by coconut oil, this ratio was decreased 8% by palm olein and 25% by corn oil. Serum triglycerides were unaffected during the palm-olein period but were significantly reduced during the corn-oil period.
  12. Fulltext The Sources of Chemical Contaminants in Food and Their Health Implications
    Rather IA, Koh WY, Paek WK, Lim J
    Front Pharmacol, 2017;8:830.
    PMID: 29204118 DOI: 10.3389/fphar.2017.00830
    Food contamination is a matter of serious concern, as the high concentration of chemicals present in the edibles poses serious health risks. Protecting the public from the degrees of the harmfulness of contaminated foods has become a daunting task. This article highlights the causes, types, and health implications of chemical contamination in food. The food contamination could be due to naturally occurring contaminants in the environment or artificially introduced by the human. The phases of food processing, packaging, transportation, and storage are also significant contributors to food contamination. The implications of these chemical contaminants on human health are grave, ranging from mild gastroenteritis to fatal cases of hepatic, renal, and neurological syndromes. Although, the government regulates such chemicals in the eatables by prescribing minimum limits that are safe for human consumption yet measures still need to be taken to curb food contamination entirely. Therefore, a variety of food needs to be inspected and measured for the presence of chemical contaminants. The preventative measures pertaining about the food contaminants problems are pointed out and discussed.
  13. Exploring the Impact of Surface Functionalization on the Reaction, Magnetophoretic, and Collective Transport Behavior of Nanoscale Zerovalent Iron
    Ng WM, Chong WH, Abdullah AZ, Lim J
    Langmuir, 2023 Dec 05;39(48):17270-17285.
    PMID: 37976676 DOI: 10.1021/acs.langmuir.3c02358
    This study provides a systematic analysis of the transport and magnetophoretic behavior of nanoscale zerovalent iron (nZVI) particles, both bare and surface functionalized by poly(ethylene glycol) (PEG) and carboxymethyl cellulose (CMC), after undergoing a chemical reaction. Here, a simple and well-investigated chemical reaction of methyl orange (MO) degradation by nZVI was used as a model reaction system, and the sand column transport and low-gradient magnetophoretic profiles of the nanoparticles were measured before and after the reaction. The results were compared over time and analyzed in the context of extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to understand the particle interactions involved. The colloidal stability of both bare and functionalized nZVI particles was enhanced after the reaction due to the consumption of metallic Fe content, resulting in a significant drop in their magnetic properties. As a result, they exhibited improved mobility across the sand column and a slower magnetophoretic collection rate compared to the unreacted particles. Here, the colloidal filtration theory (CFT) was employed to analyze the transport behavior of nZVI particles across the packed sand column. It has been observed that the surface properties of the reacted functionalized particles changed, possibly due to the entrapment of degraded products within the polymer adlayer. Moreover, quartz crystal microbalance with dissipation (QCM-D) measurements were performed to reveal the viscoelastic contribution of the adlayer formed by both bare and functionalized nZVI particles after the reaction on influencing their transport behavior across the sand column. Finally, we proposed the implementation of a high-gradient magnetic trap (HGMT) to reduce the transport distance of the colloidally stable CMC-nZVI, both before and after the reaction. This study sheds light on the behavioral changes of iron nanoparticles after the reaction and highlights environmental concerns regarding the presence of reacted nanoparticles.
  14. Navigating the microenvironment with flip and turn under quadrupole magnetophoretic steering control: Nanosphere- and nanorod-coated microbead
    Chong WH, Chan DJC, Liu CZ, Lim J
    Electrophoresis, 2024 Mar;45(5-6):357-368.
    PMID: 38044267 DOI: 10.1002/elps.202300042
    The spatiotemporal accuracy of microscale magnetophoresis has improved significantly over the course of several decades of development. However, most of the studies so far were using magnetic microbead composed of nanosphere particle for magnetophoretic actuation purpose. Here, we developed an in-house method for magnetic sample analysis called quadrupole magnetic steering control (QMSC). QMSC was used to study the magnetophoretic behavior of polystyrene microbeads decorated with iron oxide nanospheres-coated polystyrene microbeads (IONSs-PS) and iron oxide nanorods-coated polystyrene microbeads (IONRs-PS) under the influence of a quadrupole low field gradient. During a 4-s QMSC experiment, the IONSs-PS and IONRs-PS were navigated to perform 180° flip and 90° turn formations, and their kinematic results (2 s before and 2 s after the flip/turn) were measured and compared. The results showed that the IONRs-PS suffered from significant kinematic disproportion, translating a highly uneven amount of kinetic energy from the same magnitude of magnetic control. Combining the kinematic analysis, transmission electron microscopy micrographs, and vibrating sample magnetometry measurements, it was found that the IONRs-PS experienced higher fluid drag force and had lower consistency than the IONSs-PS due to its extensive open fractal nanorod structure on the bead surface and uneven magnetization, which was attributed to its ferrimagnetic nature.
  15. Fulltext A systematic review and meta-analysis of intraarterial chemotherapy for non muscle invasive bladder cancer: Promising alternative therapy in high tuberculosis burden countries
    Rahman ZA, Hidayatullah F, Lim J, Hakim L
    Arch Ital Urol Androl, 2024 Feb 16;96(1):12154.
    PMID: 38363237 DOI: 10.4081/aiua.2024.12154
    INTRODUCTION: Local therapies for high risk non-muscle-invasive bladder cancer (NMIBC) such as intravesical chemotherapy (IVC) have shown a high rate of progression and recurrence. Intravesical Bacillus Calmette-Guérin (BCG) for local therapies has been shown to reduce progression and recurrence in patient with NMIBC. However, its potential role is limited in high burden countries for tuberculosis (TB) due to its low specificity that can cause wrong diagnosis or false positive in patients with clinically diagnosed tuberculosis. BCG vaccine that has to be given for most people in tuberculosis endemic countries will induce trained immunity that could reduce the effectivity of intravesical BCG for NMIBC. Moreover, intravesical BCG is contraindicated in patient with or previous tuberculosis. The potential clinical benefit of intraarterial chemotherapy (IAC) in delaying the recurrence and progression of high-risk NMIBC have been investigated with promising results. We aimed to conduct a meta-analysis to evaluate the potential anti-tumor effect of IAC in NMIBC.

    METHODS: We conducted a comprehensive search of published articles in Cochrane Library, Pubmed, and Science-Direct to identify relevant randomized controlled trials (RCTs) and observational studies comparing IAC alone or combined with IVC versus IVC/BCG alone in NMIBC. The protocol of preferred reporting items for systematic review and meta-analysis (PRISMA) was applied to this study.

    RESULTS: Four RCTs and 4 cohort observational studies were eligible in this study and 5 studies were included in meta-analysis. The risk ratio of tumor recurrence was reduced by 35% (RR = 0.65; 95% CI 0.49-0.87; p = 0.004) in IAC plus IVC, while recurrence-free survival (RFS) was prolonged by 45% (HR: 0.55; 95% CI, 0.44-0.69; p < 0.001). The risk of tumor progression was reduced by 45% (RR = 0.55; 95% CI 0.41-0.75; p = 0.002) and tumor progression-free survival (PFS) was also prolonged by 53% (HR: 0.47; 95% CI, 0.34-0.65; p<0.001). Some RCT's had high or unclear risk of bias, meanwhile 4 included cohort studies had overall low risk of bias, therefore the pooled results need to be interpreted cautiously. Subgroup analysis revealed that the heterogeneity outcome of tumour recurrence might be attributed to the difference in NMIBC stages and grades.

    CONCLUSIONS: The IAC alone or combined with IVC following bladder tumor resection may lower the risk of tumor recurrence and progression. These findings highlight the importance of further multi institutional randomized controlled trials with bigger sample size using a standardized IAC protocol to validate the current results.

  16. The role of particle-to-cell interactions in dictating nanoparticle aided magnetophoretic separation of microalgal cells
    Toh PY, Ng BW, Ahmad AL, Chieh DC, Lim J
    Nanoscale, 2014 Nov 7;6(21):12838-48.
    PMID: 25227473 DOI: 10.1039/c4nr03121k
    Successful application of a magnetophoretic separation technique for harvesting biological cells often relies on the need to tag the cells with magnetic nanoparticles. This study investigates the underlying principle behind the attachment of iron oxide nanoparticles (IONPs) onto microalgal cells, Chlorella sp. and Nannochloropsis sp., in both freshwater and seawater, by taking into account the contributions of various colloidal forces involved. The complex interplay between van der Waals (vdW), electrostatic (ES) and Lewis acid-base interactions (AB) in dictating IONP attachment was studied under the framework of extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) analysis. Our results showed that ES interaction plays an important role in determining the net interaction between the Chlorella sp. cells and IONPs in freshwater, while the AB and vdW interactions play a more dominant role in dictating the net particle-to-cell interaction in high ionic strength media (≥100 mM NaCl), such as seawater. XDLVO predicted effective attachment between cells and surface functionalized IONPs (SF-IONPs) with an estimated secondary minimum of -3.12 kT in freshwater. This prediction is in accordance with the experimental observation in which 98.89% of cells can be magnetophoretically separated from freshwater with SF-IONPs. We have observed successful magnetophoretic separation of microalgal cells from freshwater and/or seawater for all the cases as long as XDLVO analysis predicts particle attachment. For both the conditions, no pH adjustment is required for particle-to-cell attachment.
  17. Directed assembly of bifunctional silica-iron oxide nanocomposite with open shell structure
    Che HX, Yeap SP, Osman MS, Ahmad AL, Lim J
    ACS Appl Mater Interfaces, 2014 Oct 8;6(19):16508-18.
    PMID: 25198872 DOI: 10.1021/am5050949
    The synthesis of nanocomposite with controlled surface morphology plays a key role for pollutant removal from aqueous environments. The influence of the molecular size of the polyelectrolyte in synthesizing silica-iron oxide core-shell nanocomposite with open shell structure was investigated by using dynamic light scattering, atomic force microscopy, and quartz crystal microbalance with dissipation (QCM-D). Here, poly(diallydimethylammonium chloride) (PDDA) was used to promote the attachment of iron oxide nanoparticles (IONPs) onto the silica surface to assemble a nanocomposite with magnetic and catalytic bifunctionality. High molecular weight PDDA tended to adsorb on silica colloid, forming a more extended conformation layer than low molecular weight PDDA. Subsequent attachment of IONPs onto this extended PDDA layer was more randomly distributed, forming isolated islands with open space between them. By taking amoxicillin, an antibiotic commonly found in pharmaceutical waste, as the model system, better removal was observed for silica-iron oxide nanocomposite with a more extended open shell structure.
  18. Magnetophoresis of iron oxide nanoparticles at low field gradient: the role of shape anisotropy
    Lim J, Yeap SP, Leow CH, Toh PY, Low SC
    J Colloid Interface Sci, 2014 May 1;421:170-7.
    PMID: 24594047 DOI: 10.1016/j.jcis.2014.01.044
    Magnetophoresis of iron oxide magnetic nanoparticle (IOMNP) under low magnetic field gradient (<100 T/m) is significantly enhanced by particle shape anisotropy. This unique feature of magnetophoresis is influenced by the particle concentration and applied magnetic field gradient. By comparing the nanosphere and nanorod magnetophoresis at different concentration, we revealed the ability for these two species of particles to achieve the same separation rate by adjusting the field gradient. Under cooperative magnetophoresis, the nanorods would first go through self- and magnetic field induced aggregation followed by the alignment of the particle clusters formed with magnetic field. Time scale associated to these two processes is investigated to understand the kinetic behavior of nanorod separation under low field gradient. Surface functionalization of nanoparticles can be employed as an effective strategy to vary the temporal evolution of these two aggregation processes which subsequently influence the magnetophoretic separation time and rate.
  19. Fulltext Predictors of breast cancer screening uptake: a pre intervention community survey in Malaysia
    Dahlui M, Gan DE, Taib NA, Pritam R, Lim J
    Asian Pac J Cancer Prev, 2012;13(7):3443-9.
    PMID: 22994775
    INTRODUCTION: Despite health education efforts to educate women on breast cancer and breast cancer screening modalities, the incidence of breast cancer and presentation at an advanced stage are still a problem in Malaysia.

    OBJECTIVES: To determine factors associated with the uptake of breast cancer screening among women in the general population.

    METHODS: This pre-intervention survey was conducted in a suburban district. All households were approached and women aged 20 to 60 years old were interviewed with pre-tested guided questionnaires. Variables collected included socio-demographic characteristics, knowledge on breast cancer and screening practice of breast cancer. Univariate and multivariate analysis were performed.

    RESULTS: 41.5% of a total of 381 respondents scored above average; the mean knowledge score on causes and risks factors of breast cancer was 3.41 out of 5 (SD1.609). 58.5% had ever practiced BSE with 32.5% performing it at regular monthly intervals. Uptake of CBE by nurses and by doctors was 40.7% and 37.3%, respectively. Mammogram uptake was 14.6%. Significant predictors of BSE were good knowledge of breast cancer (OR=2.654, 95% CI: 1.033-6.816), being married (OR=2.213, 95% CI: 1.201-4.076) and attending CBE (OR=1.729, 95% CI: 1.122-2.665). Significant predictors for CBE included being married (OR=2.161, 95% CI: 1.174-3.979), good knowledge of breast cancer (OR=2.286, 95% CI: 1.012-5.161), and social support for breast cancer screening (OR=2.312, 95% CI: 1.245-4.293). Women who had CBE were more likely to undergo mammographic screening of the breast (OR=5.744, 95% CI: 2.112-15.623), p<0.005.

    CONCLUSION: CBE attendance is a strong factor in promoting BSE and mammography, educating women on the importance of breast cancer screening and on how to conduct BSE. The currently opportunistic conduct of CBE should be extended to active calling of women for CBE.
  20. Fulltext Prophylactic antibiotics in orthopaedic surgery: guidelines and practice
    Yeap JS, Lim JW, Vergis M, Au Yeung PS, Chiu CK, Singh H
    Med J Malaysia, 2006 Jun;61(2):181-8.
    PMID: 16898309
    The national clinical practice guideline has recommended that prophylactic antibiotic be given in orthopaedic surgery involving joint replacements and internal fixation of fractures. The aim of this study is to assess the current antibiotics prophylaxis practice in a state level hospital. One hundred and three patients (68 males, 35 females; mean age 41.6 +/- 22.2 years) undergoing internal fixation for closed fractures and joint replacement surgery were included in this prospective study. The choice of pre and post-operative antibiotics, their dosages and duration of administration were recorded. The pre-operative antibiotics were only deemed to have been given if it was documented in the case notes and in the case of post-operative antibiotics if it was signed on the drug chart. Eighty eight percent were given pre-operative prophylactic antibiotics and 92% were given post-operative antibiotics. For patients undergoing internal fixation of fractures, the most commonly used antibiotic for both pre and post-op is intravenous cefuroxime. For joint replacement surgery, the most commonly used antibiotic is intravenous cefoperazone. The duration or number of doses of post-operative antibiotics was highly variable. It was not stated in 56% of the post-operative instructions. Post-operative antibiotic was ordered for 48 hours or longer in 10%. In conclusion, prophylactic antibiotics appear to be widely practised. The first line antibiotics as recommended by the present guideline were not given in any of the patients. Second generation followed by third generation cephalosporins are the most popular antibiotics, with a trend towards using third generation cephalosporins in arthroplasty patients. Single dose prophylaxis was rarely practised.
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