Displaying publications 1 - 20 of 25 in total

Abstract:
Sort:
  1. Investigating membrane morphology and quantity of immobilized protein for the development of lateral flow immunoassay
    Ahmad AL, Low SC, Shukor SR, Ismail A
    J Immunoassay Immunochem, 2012 Jan;33(1):48-58.
    PMID: 22181820 DOI: 10.1080/15321819.2011.591479
    This study was aimed at gaining a quantitative understanding of the effect of protein quantity and membrane pore structure on protein immobilization. The concentration of immobilized protein was measured by staining with Ponceau S and measuring its color intensity. In this study, both membrane morphology and the quantity of deposited protein significantly influenced the quantity of protein immobilization on the membrane surface. The sharpness and intensity of the red protein spots varied depending on the membrane pore structure, indicating a dependence of protein immobilization on this factor. Membranes with smaller pores resulted in a higher color density, corresponding to enhanced protein immobilization and an increased assay sensitivity level. An increased of immobilized volume has a significant jagged outline on the protein spot but, conversely, no difference in binding capacity.
  2. Optimization of polyvinylidene fluoride (PVDF) membrane fabrication for protein binding using statistical experimental design
    Ahmad AL, Ideris N, Ooi BS, Low SC, Ismail A
    J Immunoassay Immunochem, 2016;37(4):421-37.
    PMID: 27088961 DOI: 10.1080/15321819.2016.1157489
    Statistical experimental design was employed to optimize the preparation conditions of polyvinylidenefluoride (PVDF) membranes. Three variables considered were polymer concentration, dissolving temperature, and casting thickness, whereby the response variable was membrane-protein binding. The optimum preparation for the PVDF membrane was a polymer concentration of 16.55 wt%, a dissolving temperature of 27.5°C, and a casting thickness of 450 µm. The statistical model exhibits a deviation between the predicted and actual responses of less than 5%. Further characterization of the formed PVDF membrane showed that the morphology of the membrane was in line with the membrane-protein binding performance.
  3. Knowledge gaps in fibrotic interstitial lung disease in pan-Asian populations: data not missing at random?
    Chua F, Low S, Chai GT, Inoue Y, Ong V, Wongkarnjana A, et al.
    Lancet Respir Med, 2023 Jun;11(6):502-504.
    PMID: 37028437 DOI: 10.1016/S2213-2600(23)00125-X
  4. Survival predictors of major salivary gland cancer
    Elhusseiny KM, Abd-Elhay FA, Kamel MG, Abd El Hamid Hassan HH, Muhammad El Tanany HH, Hong HT, et al.
    Ann Oncol, 2018 Nov;29 Suppl 9:ix104.
    PMID: 32177708 DOI: 10.1093/annonc/mdy438.035
  5. Fulltext Screening for intermediate and severe forms of thalassaemia in discarded red blood cells: optimization and feasibility
    George E, Lai MI, Teh LK, Ramasamy R, Goh EH, Asokan K, et al.
    Med J Malaysia, 2011 Dec;66(5):429-34.
    PMID: 22390095 MyJurnal
    Detection and quantification of Hb subtypes of human blood is integral to presumptive identification of thalassaemias. It has been used in neonatal screening of thalassaemia and Hb variants. The use of discarded red blood cells following processing of the cord blood for stem cells provides readily available diagnostic material for thalassaemia screening. In this study, we determined the range of Hb subtypes in 195 consecutive cord blood samples collected for cord blood banking. The 'cord blood samples' analysed were those of the remaining red blood cells after the cord blood was processed for stem cell storage. Quantification of Hb subtypes by high performance liquid chromatography (HPLC) was done on BioRad Variant II Hb testing system. Only 73 (36.5%) of the samples could be analyzed neat without dilution. With a 1:300 dilution with wash solution the acceptable area as recommended by the manufacturer for reading of a C-gram within the 1 to 3 million ranges were achieved in all. Eighteen (9%) 12 showed classical Hb Barts (y4) prerun peaks were confirmed by Sebia Hydrasys automated Hb gel electrophoresis and quantified by Sebia Capillarys 2 capillary electrophoresis. Only 1 (0.5%) was presumptively identified with HbH disease. Due to the limited number of samples no beta-thalassaemia major, Hb E beta-thalassaemia and Hb Barts hydrops fetalis were found. The HPLC assay was possible at a cost US$ 5 per sample and a turnover time of 10 samples per hour without technical difficulties. This study reports an effective and valuable protocol for thalassaemia screening in red blood cells which would otherwise be discarded during cord blood processing. Cord blood with severe and intermediate forms of thalassaemia can be preselected and not stored.
  6. Fulltext The influence of the bowel and bladder preparation protocol for radiotherapy of prostate cancer using kilo-voltage cone beam CT: Our experience
    Heng SP, Low SH, Sivamany K
    Indian J Cancer, 2015 Oct-Dec;52(4):639-44.
    PMID: 26960504 DOI: 10.4103/0019-509X.178386
    The purpose of this study is to determine the influence of bladder and bowel preparation protocols on the dose-volume histograms (DVHs) of these organs using the cone beam computed tomography (CBCT)-based intensity modulated radiotherapy (IMRT) treatment planning for prostate cancer patients. The pelvic DVHs of 12 prostate cancer patients were studied using CBCT images obtained immediately before each treatment. Six patients had bladder and bowel preparation protocol whilst the other six patients were the control group. Contoured bladder and rectal volumes on CBCT images were compared with planning computed tomography. All patients were treated with IMRT with 7800 cGy in 39 fractions over 8 weeks. Compared with the patient with bladder preparation protocol, patients without bladder preparation instruction had higher bladder volume and dose variation. The maximum variation in bladder volume was as high as 98% in the control group. Without bowel preparation protocol, the rectal volumes were more variability. Owing to changes in rectal filling on the day of treatment, the maximum variation in rectal volume was as high as + 96%. With bowel preparation protocol, the maximum rectum volume variations were less than 25%. The changes in prostate target dose compared with planning dose were minimal as would be expected from positioning with daily image guidance and gold seed implanted.
  7. Genome-wide association study identifies five new susceptibility loci for primary angle closure glaucoma
    Khor CC, Do T, Jia H, Nakano M, George R, Abu-Amero K, et al.
    Nat Genet, 2016 May;48(5):556-62.
    PMID: 27064256 DOI: 10.1038/ng.3540
    Primary angle closure glaucoma (PACG) is a major cause of blindness worldwide. We conducted a genome-wide association study (GWAS) followed by replication in a combined total of 10,503 PACG cases and 29,567 controls drawn from 24 countries across Asia, Australia, Europe, North America, and South America. We observed significant evidence of disease association at five new genetic loci upon meta-analysis of all patient collections. These loci are at EPDR1 rs3816415 (odds ratio (OR) = 1.24, P = 5.94 × 10(-15)), CHAT rs1258267 (OR = 1.22, P = 2.85 × 10(-16)), GLIS3 rs736893 (OR = 1.18, P = 1.43 × 10(-14)), FERMT2 rs7494379 (OR = 1.14, P = 3.43 × 10(-11)), and DPM2-FAM102A rs3739821 (OR = 1.15, P = 8.32 × 10(-12)). We also confirmed significant association at three previously described loci (P < 5 × 10(-8) for each sentinel SNP at PLEKHA7, COL11A1, and PCMTD1-ST18), providing new insights into the biology of PACG.
  8. Fulltext Use of pressurised aerosol inhalers among patients attending the Chest Clinic and Primary Care Department of University Hospital, Kuala Lumpur
    Liam CK, Lo YL, Yap BH, Low SH, Ariwalagam M
    Med J Malaysia, 1993 Sep;48(3):273-9.
    PMID: 8183138
    Eighty consecutive patients who came to collect their prescriptions for pressurised aerosol inhalers at the Pharmacy of the University Hospital, Kuala Lumpur, were interviewed regarding their use of the pressurised inhaler. Their inhaler technique was also assessed. A significant proportion inhaled the steroid aerosol before the bronchodilator and 23.5% used the steroid inhaler for relief of acute dyspnoea. Only 28.8% of the 80 patients performed correctly all 6 steps necessary for the proper use of inhalers. The most common mistake was the failure to inhale slowly and deeply. Patients who had used the device for more than 5 years performed better, while correct inhaler technique was not dependent on the patient's sex, age or level of education.

    Study site: Chest clinic, University Malaya Medical Centre (UMMC)
  9. Electrophoretic interactions between nitrocellulose membranes and proteins: Biointerface analysis and protein adhesion properties
    Low SC, Shaimi R, Thandaithabany Y, Lim JK, Ahmad AL, Ismail A
    Colloids Surf B Biointerfaces, 2013 Oct 1;110:248-53.
    PMID: 23732801 DOI: 10.1016/j.colsurfb.2013.05.001
    Protein adsorption onto membrane surfaces is important in fields related to separation science and biomedical research. This study explored the molecular interactions between protein, bovine serum albumin (BSA), and nitrocellulose films (NC) using electrokinetic phenomena and the effects of these interactions on the streaming potential measurements for different membrane pore morphologies and pH conditions. The data were used to calculate the streaming ratios of membranes-to-proteins and to compare these values to the electrostatic or hydrophobic attachment of the protein molecules onto the NC membranes. The results showed that different pH and membrane pore morphologies contributes to different protein adsorption mechanisms. The protein adsorption was significantly reduced under conditions where the membrane and protein have like-charges due to electrostatic repulsion. At the isoelectric point (IEP) of the protein, the repulsion between the BSA and the NC membrane was at the lowest; thus, the BSA could be easily attached onto the membrane/solution interface. In this case, the protein was considered to be in a compact layer without intermolecular protein repulsions.
  10. Interaction of isothermal phase inversion and membrane formulation for pathogens detection in water
    Low SC, Ahmad AL, Ideris N, Ng QH
    Bioresour Technol, 2012 Jun;113:219-24.
    PMID: 22153291 DOI: 10.1016/j.biortech.2011.11.048
    The aim of this study was to explore the utilization of polymeric membrane for bio-sensing application in most efficient and rapid way. Customization of membrane formulation via phase separation study to modify its morphologies and properties enable the detection of different pathogens in a specific manner. Experimental findings (FESEM, through-pore distribution, porosity, capillary flow test and protein binding test) verified the predictions of faster capillary flow time and higher membrane's protein binding by the addition of cellulose acetate and nitrocellulose to the membrane casting dope, respectively. Throughout the phase separation study, the potential phase behavior was investigated, which was correlating various membrane structures to its performances for potential pathogens detection in water.
  11. Floral diversity and pollination strategies of three rheophytic Schismatoglottideae (Araceae)
    Low SL, Wong SY, Ooi IH, Hesse M, Städler Y, Schönenberger J, et al.
    Plant Biol (Stuttg), 2016 Jan;18(1):84-97.
    PMID: 25688576 DOI: 10.1111/plb.12320
    Homoplastic evolution of 'unique' morphological characteristics in the Schismatoglottideae - many previously used to define genera - prompted this study to compare morphology and function in connection with pollination biology for Aridarum nicolsonii, Phymatarum borneense and Schottarum sarikeense. Aridarum nicolsonii and P. borneense extrude pollen through a pair of horned thecae while S. sarikeense sheds pollen through a pair of pores on the thecae. Floral traits of spathe constriction, presence and movement of sterile structures on the spadix, the comparable role of horned thecae and thecae pores, the presence of stamen-associated calcium oxalate packages, and the timing of odour emission are discussed in the context of their roles in pollinator management. Pollinators for all investigated species were determined to be species of Colocasiomyia (Diptera: Drosophilidae).
  12. 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.
  13. Fulltext Nocardiosis in a patient with rheumatoid arthritis treated with rituximab and a summary of reported cases
    Ngiu CS, Said MS, Periyasamy P, Low SF
    BMJ Case Rep, 2010;2010.
    PMID: 22778377 DOI: 10.1136/bcr.11.2009.2421
    Rituximab is a B-cell-depleting monoclonal anti-CD20 antibody. It is widely used in haematology and rheumatology. However, usage of rituximab in immunosupressed patient has been associated with various opportunistic infections. The authors reported a case of refractory rheumatoid arthritis treated with rituximab, which later presented with non-resolving pneumonia with pulmonary nodule. Percutaneous computer tomogram guided lung biopsy was arranged to confirm the suspicion of tuberculosis, but did not yield conclusive results. Later, she presented left-chest abscess and underwent incision and drainage. The pus culture and sensitivity confirmed pulmonary nocardiosis with chest wall dissemination. She was treated with 2-week course of trimethoprim sulfamethoxazole and responded. The authors also reviewed published cases of nocardiosis post-rituximab.
  14. Clinical patterns of X linked agammaglobulinemia in Malaysian children
    Noh LM, Ismail Z, Zainudin BM, Low SM, Azizi BH, Noah RM, et al.
    Acta Paediatr Jpn, 1995 Jun;37(3):331-5.
    PMID: 7645382
    X linked agammaglobulinemia (XLA) is rarely reported from developing countries especially from South East Asia. It appears that X linked agammaglobulinemia is less common in certain ethnic groups. It is very uncommon in black people in USA and South Africa. In multiracial Malaysia we have documented five XLA in Malays and Indians but not in the Chinese that constitute about 31% of the population. First degree relatives afflicted with XLA or other primary immunodeficiencies occurred more often in our study. All showed lung involvement although the etiologic organisms involved were atypical, being Gram negative.
  15. Antibody deficiency with hyper IgM--a case report
    Noh LM, Low SM, Lajin I, Abdullah N
    Malays J Pathol, 1992 Dec;14(2):121-3.
    PMID: 1304625
    A 20-month-old Indian boy presented with recurrent pyogenic infections and failure to thrive. His IgG and IgA levels were low, but his IgM was elevated. He also had undetectable isohaemagglutinin titre and neutropenia, both parameters being poor prognostic indicators in this very rare primary immunodeficiency state--antibody deficiency with hyper IgM. Our patient subsequently succumbed to Pseudomonas aeruginosa septicaemia and meningitis inspite of aggressive antibiotic and intravenous gammaglobulin therapy. To the best of our knowledge, this is the first such case to be documented in Malaysia.
  16. Fulltext ABCC5, a gene that influences the anterior chamber depth, is associated with primary angle closure glaucoma
    Nongpiur ME, Khor CC, Jia H, Cornes BK, Chen LJ, Qiao C, et al.
    PLoS Genet, 2014 Mar;10(3):e1004089.
    PMID: 24603532 DOI: 10.1371/journal.pgen.1004089
    Anterior chamber depth (ACD) is a key anatomical risk factor for primary angle closure glaucoma (PACG). We conducted a genome-wide association study (GWAS) on ACD to discover novel genes for PACG on a total of 5,308 population-based individuals of Asian descent. Genome-wide significant association was observed at a sequence variant within ABCC5 (rs1401999; per-allele effect size =  -0.045 mm, P = 8.17 × 10(-9)). This locus was associated with an increase in risk of PACG in a separate case-control study of 4,276 PACG cases and 18,801 controls (per-allele OR = 1.13 [95% CI: 1.06-1.22], P = 0.00046). The association was strengthened when a sub-group of controls with open angles were included in the analysis (per-allele OR = 1.30, P = 7.45 × 10(-9); 3,458 cases vs. 3,831 controls). Our findings suggest that the increase in PACG risk could in part be mediated by genetic sequence variants influencing anterior chamber dimensions.
  17. Role of high resolution ultrasound in ulnar nerve neuropathy
    Radhika S, Lee YL, Low SF, Fazalina MF, Sharifah Majedah IA, Suraya A, et al.
    Med J Malaysia, 2015 Jun;70(3):158-61.
    PMID: 26248778 MyJurnal
    AIM: This study was conducted to measure the cross sectional area (CSA) of the ulnar nerve (UN) in the cubital tunnel and to evaluate the role of high-resolution ultrasonography in the diagnosis of ulnar nerve neuropathy (UNN).

    MATERIALS AND METHODS: This was a cross sectional study with 64 arms from 32 patients (34 neuropathic, 30 nonneuropathic). Diagnosis was confirmed by nerve conduction study and electromyography. The ulnar nerves were evaluated with 15MHz small footprint linear array transducer. The ulnar nerve CSA was measured at three levels with arm extended: at medial epicondyle (ME), 5cm proximal and 5cm distal to ME. Results from the neuropathic and nonneuropathic arms were compared. Independent T-tests and Pearson correlation tests were used. P value of less than 0.05 was considered significant.

    RESULTS: Mean CSA values for the UN at levels 5cm proximal to ME, ME and 5cm distal to ME were 0.055, 0.109, 0.045 cm(2) respectively in the neuropathic group and 0.049, 0.075, 0.042 cm2 respectively in the non-neuropathic group. The CSA of the UN at the ME level was significantly larger in the neuropathic group, with p value of 0.005. However, there was no statistical difference between the groups at 5cm proximal and distal to the ME, with p values of 0.10 and 0.35 respectively.

    CONCLUSION: There is significant difference in CSA values of the UN at ME between the neuropathic and non-neuropathic groups with mean CSA value above the predetermined 0.10cm(2) cut-off point. High-resolution ultrasonography is therefore useful to diagnose and follow up cases of elbow UNN.

  18. Articular cartilage regeneration with autologous marrow aspirate and hyaluronic Acid: an experimental study in a goat model
    Saw KY, Hussin P, Loke SC, Azam M, Chen HC, Tay YG, et al.
    Arthroscopy, 2009 Dec;25(12):1391-400.
    PMID: 19962065 DOI: 10.1016/j.arthro.2009.07.011
    PURPOSE: The purpose of the study was to determine whether postoperative intra-articular injections of autologous marrow aspirate (MA) and hyaluronic acid (HA) after subchondral drilling resulted in better cartilage repair as assessed histologically by Gill scoring.
    METHODS: In a goat model we created a 4-mm full-thickness articular cartilage defect in the stifle joint (equivalent to 1.6 cm in the human knee) and conducted subchondral drilling. The animals were divided into 3 groups: group A (control), no injections; group B (HA), weekly injection of 1 mL of sodium hyaluronate for 3 weeks; and group C (HA + MA), similar to group B but with 2 mL of autologous MA in addition to HA. MA was obtained by bone marrow aspiration, centrifuged, and divided into aliquots for cryopreservation. Fifteen animals were equally divided between the groups and sacrificed 24 weeks after surgery, when the joint was harvested, examined macroscopically and histologically.
    RESULTS: Of the 15 animals, 2 from group A had died of non-surgery-related complications and 1 from group C was excluded because of a joint infection. In group A the repair constituted mainly scar tissue, whereas in group B there was less scar tissue, with small amounts of proteoglycan and type II collagen at the osteochondral junction. In contrast, repair cartilage from group C animals showed almost complete coverage of the defect with evidence of hyaline cartilage regeneration. Histology assessed by Gill scoring was significantly better in group C with 1-way analysis of variance yielding an F statistic of 10.611 with a P value of .004, which was highly significant.
    CONCLUSIONS: Postoperative intra-articular injections of autologous MA in combination with HA after subchondral drilling resulted in better cartilage repair as assessed histologically by Gill scoring in a goat model.
    CLINICAL RELEVANCE: After arthroscopic subchondral drilling, this novel technique may result in better articular cartilage regeneration.
  19. Fulltext Osteochondrogenesis with Autologous Peripheral Blood Stem Cells for Osteochondral Lesions of the Talus: Report of Five Cases
    Saw KY, Jee C, Ramlan A, Dawam A, Saw YC, Low SF
    Malays Orthop J, 2022 Nov;16(3):128-131.
    PMID: 36589370 DOI: 10.5704/MOJ.2211.019
    Osteochondral lesions of the talus (OLTs) may progress to ankle arthritis needing ankle arthroplasty or arthrodesis. We report five cases of OLTs treated along the principles developed for chondrogenesis of the knee joint with autologous peripheral blood stem cells (PBSCs), resulting in repair and regeneration of the bone and cartilage components. Improvement in Ankle Osteoarthritis Scale (AOS) scores with minimum two years follow-up showed statistical significance (p < 0.05).
  20. Fulltext Recent ultrasound advancements for the manipulation of nanobiomaterials and nanoformulations for drug delivery
    Shin Low S, Nong Lim C, Yew M, Siong Chai W, Low LE, Manickam S, et al.
    Ultrason Sonochem, 2021 Dec;80:105805.
    PMID: 34706321 DOI: 10.1016/j.ultsonch.2021.105805
    Recent advances in ultrasound (US) have shown its great potential in biomedical applications as diagnostic and therapeutic tools. The coupling of US-assisted drug delivery systems with nanobiomaterials possessing tailor-made functions has been shown to remove the limitations of conventional drug delivery systems. The low-frequency US has significantly enhanced the targeted drug delivery effect and efficacy, reducing limitations posed by conventional treatments such as a limited therapeutic window. The acoustic cavitation effect induced by the US-mediated microbubbles (MBs) has been reported to replace drugs in certain acute diseases such as ischemic stroke. This review briefly discusses the US principles, with particular attention to the recent advancements in drug delivery applications. Furthermore, US-assisted drug delivery coupled with nanobiomaterials to treat different diseases (cancer, neurodegenerative disease, diabetes, thrombosis, and COVID-19) are discussed in detail. Finally, this review covers the future perspectives and challenges on the applications of US-mediated nanobiomaterials.
Related Terms
Filters
Contact Us

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

External Links