Displaying publications 1 - 20 of 119 in total

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  1. Haemolytic and phospholipase A activities of the tentacle extract of Catostylus mosaicus
    Azila N, Othman I
    Biochem. Int., 1990;20(2):291-9.
    PMID: 1969267
    An extract prepared from the tentacle of Catostylus mosaicus was shown to lyse erythrocytes from rat, rabbit and human to a different extent; those from the rat being most susceptible followed by those from rabbit and human. The haemolytic activity was dependent on the concentration of crude extract protein exhibiting a sigmoidal curve. Only 60% of the haemolytic activity was retained after treament with heat and proteolytic enzyme. The extract was devoid of hydrolytic enzymes normally present in venoms except for phospholipase A activity, which resulted in the hydrolysis of membrane phospholipids with concomittant appearance of their lyso-derivatives.
  2. Isolation, complete amino acid sequence and characterization of a previously unreported post-synaptic neurotoxin - AlphaN3, from the venom of Bungarus candidus
    Karsani SA, Othman I
    Biochem Biophys Res Commun, 2009 Nov 13;389(2):343-8.
    PMID: 19728988 DOI: 10.1016/j.bbrc.2009.08.145
    The Malayan krait (Bungarus candidus) is one of the medically most important snake species in Southeast Asia. The venom from this snake has been shown to posses both presynaptic and post-synaptic neurotoxins. We have isolated a previously uncharacterized post-synaptic neurotoxin - alphaN3 from the venom of B. candidus. Isolation of the toxin was achieved in three successive chromatography steps - gel filtration on a Sephadex G75 column, followed by ion exchange chromatography (Mono-S strong cationic exchanger) and a final reverse-phase chromatography step (PRO-RPC C18 column). Purified toxin alphaN3 was shown to have an apparent molecular weight of approximately 7 to 8 kDa on SDS-PAGE. The complete amino acid sequence of toxin alphaN3 was determined by Edman degradation and was found to share a high degree of homology with known post-synaptic neurotoxins (93% with alpha-bungarotoxin from Bungarus multicinctus, 50% with alpha cobratoxin from Naja kaouthia). The intravenous LD(50) of toxin alphaN3 was determined to be 0.16+/-0.09 microg/g in mice which is comparable to alpha-bungarotoxin from B. multicinctus. Experiments with isolated nerve-muscle preparations suggested that toxin alphaN3 was a post-synaptic neurotoxin that produced complete blockade of neuromuscular transmission by binding to nicotinic acetylcholine receptors.
  3. Survey of fungal counts and natural occurrence of aflatoxins in Malaysian starch-based foods
    Abdullah N, Nawawi A, Othman I
    Mycopathologia, 1998;143(1):53-8.
    PMID: 10205885
    In a survey of starch-based foods sampled from retail outlets in Malaysia, fungal colonies were mostly detected in wheat flour (100%), followed by rice flour (74%), glutinous rice grains (72%), ordinary rice grains (60%), glutinous rice flour (48%) and corn flour (26%). All positive samples of ordinary rice and glutinous rice grains had total fungal counts below 10(3) cfu/g sample, while among the positive rice flour, glutinous rice flour and corn flour samples, the highest total fungal count was more than 10(3) but less than 10(4) cfu/g sample respectively. However, in wheat flour samples total fungal count ranged from 10(2) cfu/g sample to slightly more than 10(4) cfu/g sample. Aflatoxigenic colonies were mostly detected in wheat flour (20%), followed by ordinary rice grains (4%), glutinous rice grains (4%) and glutinous rice flour (2%). No aflatoxigenic colonies were isolated from rice flour and corn flour samples. Screening of aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 using reversed-phase HPLC were carried out on 84 samples of ordinary rice grains and 83 samples of wheat flour. Two point four percent (2.4%) of ordinary rice grains were positive for aflatoxin G1 and 3.6% were positive for aflatoxin G2. All the positive samples were collected from private homes at concentrations ranging from 3.69-77.50 micrograms/kg. One point two percent (1.2%) of wheat flour samples were positive for aflatoxin B1 at a concentration of 25.62 micrograms/kg, 4.8% were positive for aflatoxin B2 at concentrations ranging from 11.25-252.50 micrograms/kg, 3.6% were positive for aflatoxin G1 at concentrations ranging from 25.00-289.38 micrograms/kg and 13.25% were positive for aflatoxin G2 at concentrations ranging from 16.25-436.25 micrograms/kg. Similarly, positive wheat flour samples were mostly collected from private homes.
  4. Fulltext Marek's disease herpesvirus serotype 1 in broiler breeder and layer chickens in Malaysia
    Othman I, Aklilu E
    Vet World, 2019;12(3):472-476.
    PMID: 31089320 DOI: 10.14202/vetworld.2019.472-476
    Aim: This study aimed to investigate the occurrence of Marek's disease (MD) in five poultry farms in Malaysia using postmortem examination, histopathology, and polymerase chain reaction (PCR).

    Materials and Methods: Tissue samples were collected from 24 broiler breeder chickens from four commercial broiler breeder farms and six layer chickens from one layer farm. Gross and histopathological examinations and PCR amplification of the gene encoding for avian MD herpesvirus (MDV-1) were conducted.

    Results: Gross pathological changes including hepatomegaly, splenomegaly, lymphomatous lesion at the mesentery, oviduct atrophy, and follicular atresia with lymphomatous were observed, whereas diffuse multifocal whitish infiltration of the spleen, neoplastic infiltration in the liver, intrafollicular lymphoid infiltration of the bursa of Fabricius, and lymphomatous tumor at the mesentery were seen on histopathological examinations. Confirmation by PCR showed that a total of 16 (53.33%) samples were positive for avian MDV-1. Although the outbreak involved a much larger number of birds in the respective farms, our investigation was limited based on resource and time frame allocated for the study.

    Conclusion: The findings from this study help in emphasizing the potential threats of MDV to the poultry industry globally, in general, and in Malaysia, in particular. As the scope of the current study is limited, future studies focusing on MDV pathogenesis, typing, and causes of vaccine failures are recommended.

  5. Haemolytic, oedema and haemorrhage inducing activities of tentacular extract of the blubber jellyfish (Catostylus mosaicus)
    Azila N, Siao FK, Othman I
    Comp Biochem Physiol C Comp Pharmacol Toxicol, 1991;99(1-2):153-6.
    PMID: 1675964
    1. An extract prepared from the tentacle of the jellyfish (CE), Catostylus mosaicus exhibited haemolytic, oedema and haemorrhage-inducing activities. 2. Acetone treatment of the tentacle extract produced an acetone soluble extract (AE) which showed an increase in specific haemolytic and haemorrhagic activities by 25- and 120-fold respectively; the minimum oedema dose was reduced by 30-fold. 3. The AE caused a rapid onset of oedema in the mouse foot pad. The effect was long-lasting, reaching a maximum in about 30 min after injection and sustained up to 4 hr. 4. Fractionation of the AE on Q-Sepharose gave 4 bound fractions which induced oedema and haemorrhage; however only 3 of the fractions exhibited haemolytic activity.
  6. Strategies and validation for siRNA-based therapeutics for the reversal of multi-drug resistance in cancer
    Fatemian T, Othman I, Chowdhury EH
    Drug Discov Today, 2014 Jan;19(1):71-8.
    PMID: 23974068 DOI: 10.1016/j.drudis.2013.08.007
    Resistance of cancer cells to anticancer drugs is the main reason for the failure of traditional cancer treatments. Various cellular components and different loops within the signaling pathways contribute to drug resistance which could be modulated with the aim to restore drug efficacy. Unveiling the molecular mechanisms for cancer drug resistance has now paved the way for the development of novel approaches to regulate the response rates to anticancer drugs at the genetic level. The recent progress on identification and validation of the vital genes directly or indirectly involved in development of cancer drug resistance with the aid of the specific knock down ability of RNA interference technology is discussed in this review.
  7. Fulltext Anti-High Mobility Group Box-1 Monoclonal Antibody Attenuates Seizure-Induced Cognitive Decline by Suppressing Neuroinflammation in an Adult Zebrafish Model
    Paudel YN, Othman I, Shaikh MF
    Front Pharmacol, 2020;11:613009.
    PMID: 33732146 DOI: 10.3389/fphar.2020.613009
    Epilepsy is a chronic brain disease afflicting around 70 million global population and is characterized by persisting predisposition to generate epileptic seizures. The precise understanding of the etiopathology of seizure generation is still elusive, however, brain inflammation is considered as a major contributor to epileptogenesis. HMGB1 protein being an initiator and crucial contributor of inflammation is known to contribute significantly to seizure generation via activating its principal receptors namely RAGE and TLR4 reflecting a potential therapeutic target. Herein, we evaluated an anti-seizure and memory ameliorating potential of an anti-HMGB1 monoclonal antibody (mAb) (1, 2.5 and 5 mg/kg, I.P.) in a second hit Pentylenetetrazol (PTZ) (80 mg/kg, I.P.) induced seizure model earlier stimulated with Pilocarpine (400 mg/kg, I.P.) in adult zebrafish. Pre-treatment with anti-HMGB1 mAb dose-dependently lowered the second hit PTZ-induced seizure but does not alter the disease progression. Moreover, anti-HMGB1 mAb also attenuated the second hit Pentylenetetrazol induced memory impairment in adult zebrafish as evidenced by an increased inflection ration at 3 and 24 h trail in T-maze test. Besides, decreased level of GABA and an upregulated Glutamate level was observed in the second hit PTZ induced group, which was modulated by pre-treatment with anti-HMGB1 mAb. Inflammatory responses occurred during the progression of seizures as evidenced by upregulated mRNA expression of HMGB1, TLR4, NF-κB, and TNF-α, in a second hit PTZ group, which was in-turn downregulated upon pre-treatment with anti-HMGB1 mAb reflecting its anti-inflammatory potential. Anti-HMGB1 mAb modulates second hit PTZ induced changes in mRNA expression of CREB-1 and NPY. Our findings indicates anti-HMGB1 mAb attenuates second hit PTZ-induced seizures, ameliorates related memory impairment, and downregulates the seizure induced upregulation of inflammatory markers to possibly protect the zebrafish from the incidence of further seizures through via modulation of neuroinflammatory pathway.
  8. Shotgun Proteomics and Mass Spectrometry as a Tool for Protein Identification and Profiling of Bio-Carrier-Based Therapeutics on Human Cancer Cells
    Abidin SAZ, Othman I, Naidu R
    Methods Mol Biol, 2021;2211:233-240.
    PMID: 33336281 DOI: 10.1007/978-1-0716-0943-9_16
    Shotgun proteomics has been widely applied to study proteins in complex biological samples. Combination of high-performance liquid chromatography with mass spectrometry has allowed for comprehensive protein analysis with high resolution, sensitivity, and mass accuracy. Prior to mass spectrometry analysis, proteins are extracted from biological samples and subjected to in-solution trypsin digestion. The digested proteins are subjected for clean-up and injected into the liquid chromatography-mass spectrometry system for peptide mass identification. Protein identification is performed by analyzing the mass spectrometry data on a protein search engine software such as PEAKS studio loaded with protein database for the species of interest. Results such as protein score, protein coverage, number of peptides, and unique peptides identified will be obtained and can be used to determine proteins identified with high confidence. This method can be applied to understand the proteomic changes or profile brought by bio-carrier-based therapeutics in vitro. In this chapter, we describe methods in which proteins can be extracted for proteomic analysis using a shotgun approach. The chapter outlines important in vitro techniques and data analysis that can be applied to investigate the proteome dynamics.
  9. Fulltext The Role of MicroRNAs in Lung Cancer Metabolism
    Azizi MIHN, Othman I, Naidu R
    Cancers (Basel), 2021 Apr 05;13(7).
    PMID: 33916349 DOI: 10.3390/cancers13071716
    MicroRNAs (miRNAs) are short-strand non-coding RNAs that are responsible for post-transcriptional regulation of many biological processes. Their differential expression is important in supporting tumorigenesis by causing dysregulation in normal biological functions including cell proliferation, apoptosis, metastasis and invasion and cellular metabolism. Cellular metabolic processes are a tightly regulated mechanism. However, cancer cells have adapted features to circumvent these regulations, recognizing metabolic reprogramming as an important hallmark of cancer. The miRNA expression profile may differ between localized lung cancers, advanced lung cancers and solid tumors, which lead to a varying extent of metabolic deregulation. Emerging evidence has shown the relationship between the differential expression of miRNAs with lung cancer metabolic reprogramming in perpetuating tumorigenesis. This review provides an insight into the role of different miRNAs in lung cancer metabolic reprogramming by targeting key enzymes, transporter proteins or regulatory components alongside metabolic signaling pathways. These discussions would allow a deeper understanding of the importance of miRNAs in tumor progression therefore providing new avenues for diagnostic, therapeutic and disease management applications.
  10. Fulltext Digital Technologies in the Architecture, Engineering and Construction (AEC) Industry-A Bibliometric-Qualitative Literature Review of Research Activities
    Manzoor B, Othman I, Pomares JC
    Int J Environ Res Public Health, 2021 06 06;18(11).
    PMID: 34204147 DOI: 10.3390/ijerph18116135
    Digital technologies (DTs) are proven helpful in the Architecture, Engineering and Construction (AEC) industry due to their varied benefits to project stakeholders, such as enhanced visualization, better data sharing, reduction in building waste, increased productivity, sustainable performance and safety improvement. Therefore, researchers have conducted various studies on DTs in the AEC industry over the year; however, this study explores the state-of-the-art research on DTs in the AEC industry by means of a bibliometric-qualitative review method. This research would uncover new knowledge gaps and practical needs in the domain of DTs in the AEC industry. In addition, bibliometric analysis was carried out by utilizing academic publications from Scopus (i.e., 11,047 publications for the AEC industry, 1956 for DTs and 1778 for DTs in the AEC industry). Furthermore, a qualitative review was further conducted on 200 screened selected research publications in the domain of DTs. This study brings attention to the body of knowledge by envisioning trends and patterns by defining key research interests, journals, countries, new advancements, challenges, negative attitudes and future directions towards DTs in the AEC industry. However, this study is the first in its vital importance and uniqueness by providing a broad updated review of DTs in the AEC literature. Furthermore, this research laid a foundation for future researchers, policy makers and practitioners to explore the limitations in future research.
  11. Fulltext Targeted CYP2E1 quantification and its correlation to currently acceptable clinical biochemical indices
    Yap CG, Zaini A, Othman I
    J Biol Res (Thessalon), 2016 Dec;23:15.
    PMID: 27376033 DOI: 10.1186/s40709-016-0052-9
    The Cytochrome P450 enzymes are commonly known for their major role in metabolism. Besides its metabolic role, CYP2E1 gene expression has been associated with the onset of diabetic nephropathy. CYP2E1 protein elevation has also been reported to be responsible for the production of reactive oxygen species. The aims of this study were (i) to optimize and validate a targeted proteomic approach for quantitating CYP2E1 and validating it as a suitable clinical test, (ii) to investigate the concurrency between ESI-LCMS-MS quantitated circulating CYP2E1 and gold standard indices in the context of outpatient point-of-care clinical settings involving various groups of diabetic patients and (iii) to investigate the concurrency profile of circulating CYP2E1 protein, CYP2E1 gene expression and reactive oxygen species (ROS). This is a cross sectional study involving three groups of subjects (n = 166): control, pre-diabetes, and diabetes. We optimized a targeted proteomic approach for absolute quantification of CYP2E1. "YPEIEEK" and "GTVVVPTLYDNQEFPDPEK" were the representative peptides of CYP2E1 for our analytical method. Deuterated forms of "YPEIEEK" and "GTVVVPTLYDNQEFPDPEK" were used as internal standards. Lymphocytes were isolated from whole blood, microsomes were prepared, followed by in-solution digestion for production of tryptic peptides. Amounts of "YPEIEEK" and "GTVVVPTLYDNQEFPDPEK" from patients' samples were calculated from a calibration curve.
  12. Fulltext A Case of Medialized Lateral Maxillary Sinus Wall: A Pillar of Support
    Othman IA, Hashim ND, Nazimi AJ
    Case Rep Med, 2018;2018:4053531.
    PMID: 29861735 DOI: 10.1155/2018/4053531
    The number of maxillofacial trauma (MFT) cases attended in the Emergency Department is progressively increasing in trend, owing to the rising statistics of motor-vehicle accidents (MVAs) and urban assaults in addition to occupational-related injuries. Prompt and thorough assessment is important for accurate diagnosis and paramount treatment plans. We will be discussing a case of unusual presentation of an orbital floor fracture post-MVA which was treated conservatively based on the clinical assessments during follow-ups, supported by radiological findings. We will also briefly discuss the different radiological modalities available in assessing MFT and late presentation of enophthalmos.
  13. Fulltext Synergistic antibacterial effect of co-administering adipose-derived mesenchymal stromal cells and Ophiophagus hannah L-amino acid oxidase in a mouse model of methicillin-resistant Staphylococcus aureus-infected wounds
    Mot YY, Othman I, Sharifah SH
    Stem Cell Res Ther, 2017 01 23;8(1):5.
    PMID: 28114965 DOI: 10.1186/s13287-016-0457-2
    BACKGROUND: Mesenchymal stromal cells (MSCs) and Ophiophagus hannah L-amino acid oxidase (Oh-LAAO) have been reported to exhibit antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). Published data have indicated that synergistic antibacterial effects could be achieved by co-administration of two or more antimicrobial agents. However, this hypothesis has not been proven in a cell- and protein-based combination. In this study, we investigate if co-administration of adipose-derived MSCs and Oh-LAAO into a mouse model of MRSA-infected wounds would be able to result in a synergistic antibacterial effect.

    METHODS: MSCs and Oh-LAAO were isolated and characterized by standard methodologies. The effects of the experimental therapies were evaluated in C57/BL6 mice. The animal study groups consisted of full-thickness uninfected and MRSA-infected wound models which received Oh-LAAO, MSCs, or both. Oh-LAAO was administered directly on the wound while MSCs were delivered via intradermal injections. The animals were housed individually with wound measurements taken on days 0, 3, and 7. Histological analyses and bacterial enumeration were performed on wound biopsies to determine the efficacy of each treatment.

    RESULTS: Immunophenotyping and differentiation assays conducted on isolated MSCs indicated expression of standard cell surface markers and plasticity which corresponds to published data. Characterization of Oh-LAAO by proteomics, enzymatic, and antibacterial assays confirmed the identity, purity, and functionality of the enzyme prior to use in our subsequent studies. Individual treatments with MSCs and Oh-LAAO in the infected model resulted in reduction of MRSA load by one order of magnitude to the approximate range of 6 log10 colony-forming units (CFU) compared to untreated controls (7.3 log10 CFU). Similar wound healing and improvements in histological parameters were observed between the two groups. Co-administration of MSCs and Oh-LAAO reduced bacterial burden by approximately two orders of magnitude to 5.1 log10 CFU. Wound closure measurements and histology analysis of biopsies obtained from the combinational therapy group indicated significant enhancement in the wound healing process compared to all other groups.

    CONCLUSIONS: We demonstrated that co-administration of MSCs and Oh-LAAO into a mouse model of MRSA-infected wounds exhibited a synergistic antibacterial effect which significantly reduced the bacterial count and accelerated the wound healing process.

  14. Fulltext Impact of 3D Printing on the Overall Project Success of Residential Construction Projects Using Structural Equation Modelling
    Waqar A, Othman I, Pomares JC
    Int J Environ Res Public Health, 2023 Feb 21;20(5).
    PMID: 36900821 DOI: 10.3390/ijerph20053800
    After a decade of research and development, 3D printing is now an established technique in the construction sector, complete with its own set of accepted standards. The use of 3D printing in construction might potentially improve the outcome of the project as a whole. However, traditional strategies are often used in the residential construction industry in Malaysia, which causes serious public safety and health issues along with a negative impact on the environment. In the context of project management, overall project success (OPS) has five dimensions, such as cost, time, quality, safety, and environment. Understanding the role of 3D printing in relation to OPS dimensions in Malaysian residential construction projects would allow construction professionals to adopt 3D printing more easily. The aim of the study was to find the impact of 3D construction printing on OPS while considering the implications for all five dimensions. Fifteen professionals were interviewed to first evaluate and summarise the impact factors of 3D printing using the current literature. Then, a pilot survey was conducted, and the results were checked using exploratory factor analysis (EFA). The feasibility of 3D printing in the building sector was investigated by surveying industry experts. Partial least squares structural equation modelling was used to investigate and validate the fundamental structure and linkages between 3D printing and OPS (PLS-SEM). A strong correlation was found between 3D printing in residential projects and OPS. Highly positive implications are indicated by the environmental and safety dimensions of OPS. Malaysian decision-makers may look to the outcomes of introducing 3D printing into the residential construction industry as a modern method for increasing environmental sustainability, public health and safety, reducing cost and time, and increasing the quality of construction work. With this study's findings in hand, construction engineering management in Malaysia's residential building sector might benefit from a deeper understanding of how 3D printing is used for improving environmental compliance, public health and safety, and project scope.
  15. Radiation risk for patients undergoing cardiac computed tomography examinations
    Alkhorayef M, Sulieman A, Alzahrani K, Abuzaid M, Alomair OI, Almuwannis M, et al.
    Appl Radiat Isot, 2021 Feb;168:109520.
    PMID: 33307438 DOI: 10.1016/j.apradiso.2020.109520
    The various technological advancements in computed tomography (CT) have resulted in remarkable growth in the use of CT imaging in clinical practice, not the least of which has been its establishment as the most valuable imaging examination for the assessment of cardiovascular system disorders. The objective of this study was to assess the effective radiation dose and radiation risk for patients during cardiac CT procedures, based on studies from four different hospitals equipped with 128 slice CT equipment. A total of eighty-three patients were investigated in this study with different clinical indications. Effective doses were also calculated using software based on Monte Carlo simulation. The mean patient age (years), weight (kg), and body mass index (BMI (kg/m2)) were 49 ± 11, 82 ± 12, and 31 ± 6, respectively. The results of the study revealed that the tube voltage (kVp) and tube current-exposure time product (mAs) ranged between 100 to 140 and 50 to 840 respectively. The overall average patient dose values for the volume CT dose index [(CTDIvol), in mGy)] and dose length product (DLP) (in mGy·cm) were 34.8 ± 15 (3.7-117.0) and 383.8 ± 354 (46.0-3277.0) respectively. The average effective dose (mSv) was 15.2 ± 8 (1.2-61.8). The radiation dose values showed wide variation between different hospitals and even within the same hospital. The results indicate the need to optimize radiation dose and to establish diagnostic reference levels (DRLs) for patients undergoing coronary computed tomography angiography (CCTA), also to harmonize the imaging protocols to ensure reduced radiation risk.
  16. Performance of aerobic granular sludge at variable circulation rate in anaerobic-aerobic conditions
    Harun H, Anuar AN, Ujang Z, Rosman NH, Othman I
    Water Sci Technol, 2014;69(11):2252-7.
    PMID: 24901619 DOI: 10.2166/wst.2014.156
    Aerobic granular sludge (AGS) has been applied to treat a broad range of industrial and municipal wastewater. AGS can be developed in a sequencing batch reactor (SBR) with alternating anaerobic-aerobic conditions. To provide anaerobic conditions, the mixed liquor is allowed to circulate in the reactor without air supply. The circulation flow rate of mixed liquor in anaerobic condition is the most important parameter of operation in the anaerobic-AGS processes. Therefore, this study investigates the effect of circulation rate on the performance of the SBR with AGS. Two identical reactors namely R1 and R2 were operated using fermented soy sauce wastewater at circulation rate of 14.4 and 36.0 l/h, respectively. During the anaerobic conditions, the wastewater was pumped out from the upper part of the reactor and circulated back into the bottom of the reactor for 230 min. A compact and dense AGS was observed in both reactors with a similar diameter of 2.0 mm in average, although different circulation rates were adopted. The best reactor performance was achieved in R2 with chemical oxygen demand removal rate of 89%, 90% total phosphorus removal, 79% ammonia removal, 10.1 g/l of mixed liquor suspended solids and a sludge volume index of 25 ml/g.
  17. Methotrexate- and cyclophosphamide-embedded pure and strontiumsubstituted carbonate apatite nanoparticles for augmentation of chemotherapeutic activities in breast cancer cells
    Tiash S, Othman I, Rosli R, Chowdhury EH
    Curr Drug Deliv, 2014;11(2):214-22.
    PMID: 24328684
    Most of the classical drugs used today to destroy cancer cells lead to the development of acquired resistance in those cells by limiting cellular entry of the drugs or exporting them out by efflux pumps. As a result, higher doses of drugs are usually required to kill the cancer cells affecting normal cells and causing numerous side effects. Accumulation of the therapeutic level of drugs inside the cancer cells is thus required for an adequate period of time to get drugs' complete therapeutic efficacy minimizing the side effects on normal cells. In order to improve the efficacy of chemotherapeutic drugs, nanoparticles of carbonate apatite and its strontium (Sr(2+))-substituted derivative were used in this study to make complexes with three classical anticancer drugs, methotrexate, cyclophosphamide and 5-flurouracil. The binding affinities of these drugs to apatite were evaluated by absorbance and HPLC analysis and the therapeutic efficacy of drug-apatite complexes was determined by cell viability assay. Carbonate apatite demonstrated significant binding affinity towards methotrexate and cyclophosphamide leading to more cellular toxicity than free drugs in MCF-7 and 4T1 breast cancer cells. Moreover, Sr(2+) substitution in carbonate apatite with resulting tiny particles less than 100 nm in diameter further promoted binding of methotrexate to the nanocarriers indicating that Sr(2+)-substituted apatite nanoparticles have the high potential for loading substantial amount of anti-cancer drugs with eventual more therapeutic effectiveness.
  18. Fulltext Assessment of muscle fatigue associated with prolonged standing in the workplace
    Halim I, Omar AR, Saman AM, Othman I
    Saf Health Work, 2012 Mar;3(1):31-42.
    PMID: 22953228 DOI: 10.5491/SHAW.2012.3.1.31
    The objectives of this study were to determine the psychological fatigue and analyze muscle activity of production workers who are performing processes jobs while standing for prolonged time periods.
  19. Controlled release of insulin in blood from strontium-substituted carbonate apatite complexes
    Ahmad A, Othman I, Md Zain AZ, Chowdhury EH
    Curr Drug Deliv, 2015;12(2):210-22.
    PMID: 22452407
    Diabetes mellitus is a chronic disease accompanied by a multitude of problems worldwide with subcutaneously administered insulin being the most common therapy currently. Controlledrelease insulin is assumed to be of high importance for long-term glycaemic control by reducing the number of daily injections. Long-acting insulin also mimics the basal insulin levels in normal individuals that may be lacking in diabetic patients. Nanoparticles of carbonate apatite as established for efficient intracellular transport of DNA and siRNA have the potential to be used for sustained release of insulin as responsive nano-carriers. The flexibility in the synthesis of the particles over a wide range of pHs with eventual adjustment of pH-dependent particle dissolution and the manageable variability of particle-integrity by incorporating selective ions into the apatite structure are the promising features that could help in the development of sustained release formulations for insulin. In particular strontium-incorporated carbonate apatite particles were formulated and compared with those of unsubstituted apatite in the context of insulin binding and subsequent release kinetics in DMEM, simulated buffer and finally human blood over a period of 20 hours. Clearly, the former demonstated to have a stronger electrostatic affinity towards the acidic insulin molecules and facilitate to some extent sustained release of insulin by preventing the initial burst effect at physiological pH in comparison with the latter. Thus, our findings suggest that optimization of the carbonate apatite particle composition and structure would serve to design an ideal insulin nano-carrier with a controlled release profile.
  20. HLA variants rs9271366 and rs9275328 are associated with systemic lupus erythematosus susceptibility in Malays and Chinese
    Chai HC, Phipps ME, Othman I, Tan LP, Chua KH
    Lupus, 2013 Feb;22(2):198-204.
    PMID: 23257407 DOI: 10.1177/0961203312470183
    BACKGROUND: Human leukocyte antigen (HLA) antigens and genes have long been reported associated with systemic lupus erythematosus (SLE) susceptibility in many populations. With the advance in technologies such as genome-wide association studies, many newly discovered SLE-associated single-nucleotide polymorphisms (SNPs) have been reported in recent years. These include HLA-DRB1/HLA-DQA1 rs9271366 and HLA-DQB1/HLA-DQA2 rs9275328. Our aim was to investigate these SNPs in a Malaysian SLE cohort.
    MATERIALS AND METHODS: SNPs rs9271366 and rs9275328 were screened across 790 Malaysian citizens from three ethnic groups (360 patients and 430 healthy volunteers) by Taqman SNP genotyping assays. Allele and genotyping frequencies, Hardy-Weinberg equilibrium, Fisher's exact test and odds ratio were calculated for each SNP and ethnic group. Linkage disequilibrium and interaction between the two SNPs were also evaluated.
    RESULTS: The minor allele G and its homozygous genotype GG of HLA-DRB1/HLA-DQA1 rs9271366 significantly increased the SLE susceptibility in Malaysian patients, including those of Malay and Chinese ethnicity (odds ratio (OR) > 1, p 
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