Displaying publications 1 - 20 of 118 in total

  1. Mohamed N, Jackson N
    Blood Rev, 1998 Sep;12(3):163-70.
    PMID: 9745886
    In many of the parts of the world where thalassaemia is common, the blood supply is inadequate or unsafe, and desferrioxamine is too expensive for routine use. We classify some patients as having 'severe thalassaemia intermedia', i.e. those with moderately severe thalassaemia who can survive without regular transfusions, but who are at risk of many complications which are reviewed here. These include bone deformity and fractures, extramedullary haemopoietic tumours, leg ulcers, autoimmune haemolysis and, especially after splenectomy, thromboembolism and infection. An increase in the quality and safety of the blood supply, and a cheaper and/or oral iron chelator, would enable more of these patients to be treated as thalassaemia major and have improved survival and quality of life.
  2. Yap CY, Mohamed N
    Chemosphere, 2008 Oct;73(5):685-91.
    PMID: 18718637 DOI: 10.1016/j.chemosphere.2008.07.014
    An electrogenerative flow-through reactor with an activated reticulated vitreous carbon cathode was developed. The influence of palladium-tin activation of the cathode towards gold deposition was studied by cyclic voltammetry. The reactor proved to be efficient in recovering more than 99% of gold within 4 h of operation. The performance of the reactor was evaluated with initial gold concentrations of 10, 100 and 500 mg L-1 and various electrolyte flow rates. Gold recovery was found to be strongly dependent on electrolyte flow rate and initial gold concentration in the cyanide solution under the experimental conditions used.
  3. Yap CY, Mohamed N
    Chemosphere, 2007 Apr;67(8):1502-10.
    PMID: 17296217
    Traditional methods for the recovery of gold from electronic scrap by hydrometallurgy were cyanidation followed by adsorption on activated carbon or cementation onto zinc dust and by electrowinning. In our studies, a static batch electrochemical reactor operating in an electrogenerative mode was used in gold recovery from cyanide solutions. A spontaneous chemical reaction will take place in the reactor and generate an external flow of current. In this present work, a static batch cell with an improved design using three-dimensional cathodes namely porous graphite and reticulated vitreous carbon (RVC) and two-dimensional cathode materials, copper and stainless steel plates were coupled with a zinc anode. The electrogenerative system was demonstrated and the performance of the system using various cathode materials for gold recovery was evaluated. The system resulted in more than 90% gold being recovered within 3h of operation. Activated RVC serves as a superior cathode material having the highest recovery rate with more than 99% of gold being recovered in 1h of operation. The morphology of gold deposits on various cathode materials was also investigated.
  4. Mohamed N, Nordin R
    Malays J Med Sci, 2004 Jul;11(2):12-8.
    PMID: 22973122
    Many published studies that examined the effect of lead exposure on neurobehavioral performances were conducted in confined manufacturing environment with low to moderate blood lead levels as a marker of exposure. This study was conducted in a general environmental setting with very low exposure intensity and blood lead levels. The objective of the study was to determine the effect of very low blood lead levels (below 10 μg/dl) on the neurobehavioral performances of policemen in Kota Bharu, Kelantan. The study, conducted between August 25(th) and October 20(th) 2001, was cross-sectional in design and comprised of 89 policemen working in Kota Bharu district. The lead concentration of venous blood was determined using graphite furnace absorption spectrometer. We assessed neurobehavioral performances using the WHO Neurobehavioral Core Test Battery (NCTB). The mean blood lead concentration was 2.5 + 1.0 mg/dl. Among the seven tests performed, the positive effect of blood lead on Benton visual retention was not significant after controlling for the confounding effect of smoke-dose. This study suggested that very low blood lead levels have no significant effects on the neurobehavioral performances. Therefore, more studies with blood lead levels below the recommended environmental limit of 10 mg/dl, as recommended by Centers for Disease Control (CDC), be conducted in order to justify that limit.
  5. Abdullah N, Mohamed N
    Oncol Lett, 2021 Nov;22(5):806.
    PMID: 34630713 DOI: 10.3892/ol.2021.13067
    Malaysia is a developing country made up of three main ethnicities: Malay, Chinese and Indian. There are significant ethnic differences with regard to the type of daily food and cooking methods, contraception, breast-feeding preferences, confinement period and care, postmenopausal intake and influence of the traditional healer. Breast cancer is the most common cancer among Malaysian women across all three ethnicities. However, the National Cancer Registry and local medical centres have documented ethnic differences in breast cancer risk (Chinese, 40.7 per 100,000; Indian, 38.1 per 100,000; Malay, 31.5 per 100,000), peak age (youngest in the Malays), stage at presentation (largest percentage at advanced stage among the Malays) and survival (poorest survival rate among the Malays). The Malays have several practices that are protective against breast cancer compared with the Chinese. However, the Malays have strong beliefs in the traditional healer, which contribute to the delay in getting treatment, causing a poor outcome and a low survival rate. The highest BRCA1 and 2 genetic mutation incidence is amongst the Chinese, but the Malays have the largest triple-negative breast cancer rates. These factors may also contribute to the statistical breast cancer data.
  6. Fazilah A, Azemi MN, Karim AA, Norakma MN
    J Agric Food Chem, 2009 Feb 25;57(4):1527-31.
    PMID: 19166335 DOI: 10.1021/jf8028013
    Hemicelluloses from oil palm frond (OPF) were extracted using 3 M potassium hydroxide (KOH) for 4 h at 40 degrees C with stirring at 400 rpm to obtain hemicelluloses A and B. The total yield of the hemicellulose isolated from OPF was 33% (dry weight). Both hemicelluloses A and B were then subjected to hydrothermal treatment at 121 degrees C and 1.03 x 10(5) Pa for 10, 30, and 50 min. Physicochemical characterizations of hydrothermally treated hemicelluloses, such as Klason lignin content and reducing sugar content, were performed to study the effect of autohydrolysis processing on OPF-derived hemicelluloses. It was shown that Klason lignin content in hemicellulose A was higher than that in hemicellulose B and decreased after hydrothermal treatment. Hydrothermal treatment enhanced the solubility of hemicelluloses, which reflects their higher reducing sugar content. Monosaccharide analysis using HPLC showed that xylose was the predominant monosaccharide for both hemicelluloses A and B.
  7. Sadatullah S, Mohamed N, Razak F
    Ann Med Health Sci Res, 2014 Jul;4(4):526-31.
    PMID: 25221698 DOI: 10.4103/2141-9248.139301
    Ozone is an unstable gas, capable of oxidizing any biological entity. It is an effective bactericide in its gaseous as well as aqueous form.
  8. Abukhadir SS, Mohamed N, Mohamed N
    Curr Drug Targets, 2013 Dec;14(13):1601-10.
    PMID: 24138635
    Osteoporosis is the most common bone disease in humans; it represents a major public health problem. This chronic disease is characterized by increase in bone fracture due to: reduced bone mass, deterioration of micro architectural and decreased bone strength, bone fragility; and bone mineral density 2.5 or more standard deviations below the normal mean. Secondary osteoporosis is a common cause of osteoporosis, and there are many underlying risk factors for osteoporosis. Chronic alcohol abuse is one of the modifiable risk factors in osteoporosis. There is evidence of correlation between chronic alcohol abuse and low bone mass. Alcohol is directly toxic to the bone; with increased incidence of fractures and complications. Although there is a paucity of studies regarding alcohol induced osteoporosis therapy, it can be classified into antiresorptive therapy and anabolic therapy. Bisphosphonates have been demonstrated to be clinically relevant to prevent bone damage associated with alcohol use while parathyroid hormone increased bone mineralization as well as bone formation in alcohol treated rats. Vitamin D supplementation could prevent bone toxicity in chronic drinkers. This review discussed the pathogenesis of alcohol-induced osteoporosis and the agents available for its treatment. Other potential therapies are also discussed.
  9. Abdul-Majeed S, Mohamed N, Soelaiman IN
    Life Sci, 2015 Mar 15;125:42-8.
    PMID: 25534439 DOI: 10.1016/j.lfs.2014.12.012
    Statins are competitive inhibitors of HMGCoA reductase and are commonly used as antihypercholesterolemic agents. Experimental studies clearly demonstrate the beneficial effects of statins on bone. Tocotrienols have also been shown to have anti-osteoporotic effects on the skeletal system. This study was conducted to observe the effect of a combination of delta-tocotrienol and lovastatin on structural bone histomorphometry and bone biomechanical strength in a postmenopausal rat model at clinically tolerable doses, and to compare it with the effect of delta-tocotrienol or lovastatin.
  10. Rufus P, Mohamed N, Shuid AN
    Curr Drug Targets, 2013 Dec;14(14):1689-93.
    PMID: 24354584
    Osteoporosis is a metabolic bone disorder that affects both men and women worldwide. It causes low bone mass and therefore increases bone susceptibility to fracture when bone undergoes a minor trauma. Lack of estrogen is the principal cause of osteoporosis. Estrogen, calcium, calcitonin, vitamin D and several antioxidants help in the prevention of osteoporosis. In order to effectively treat osteoporosis, there has been an extended research on the biological activities of traditional medicines since synthetic medicines possess several side effects that reduce their efficacy. Therefore, there is a need to develop new treatment alternatives for osteoporosis. This review centres on the scientific researches carried out on the evaluation of Chinese traditional medicines in the treatment of osteoporosis. Various plants like Achyranthes bidentata, Davallia formosana, polygonatum sibiricum, Cibotium barometz, Er-Zhi-Wan, Curculigo orchioides and a combined treatment of Hachimi-jio-gan (Ba-Wei-Di-Huang-Wan) with alendronate proved active in preventing post-menopausal osteoporosis.
  11. Ibrahim N', Mohamed N, Shuid AN
    Curr Drug Targets, 2013 Dec;14(13):1524-32.
    PMID: 23876090
    Fracture healing is a process of recovering injured bone tissue forms and functions. Osteoporosis can delay the healing process, which contributes to personal suffering and loss of activities. Osteoporosis patients tend to lose bone mass at the metaphyseal region which require treatment to increase bone mass. Postmenopausal osteoporosis is the most common osteoporosis that occurs in women which subsequently resulted in fractures even under slight trauma. Estrogen Replacement Therapy (ERT), the recommended therapy for postmenopausal osteoporosis, is associated with higher risk of breast cancer, ovarian cancer and cardiovascular diseases. As osteoporotic fractures are becoming a public health issue, alternative treatment is now being thoroughly explored. The potential agent is statins, the HMG-CoA reductase inhibitor which is widely used for hypercholesterolemia treatment. Statins have been found to increase bone mass by stimulation of Bone morphogenetic protein-2 (BMP-2) expression and Vascular Endothelial Growth Factor (VEGF) production. However, these bone forming effects were achieved at very high systemic doses. Therefore, studies on locally applied statins are required to further explore the ability of statins to stimulate bone formation at acceptable doses for better fracture healing. This review highlights the animal and clinical studies on fracture healing promotions by statins and the mechanisms involved.
  12. Abdul-Majeed S, Mohamed N, Soelaiman IN
    Curr Drug Targets, 2013 Dec;14(13):1579-90.
    PMID: 23848479
    Skeletal tissue undergoes continuous remodeling which makes it unique among other body tissues. Osteoporosis is a common bone metabolic disorder affecting both men and women. Osteoporosis and its complications mainly osteoporotic fractures, have a high impact on health and economy. Current approved medications are associated with numerous side effects, which limit their use. Identification of a new and safe therapy is mandatory. Statins, also known as HMGCoA reductase inhibitors, are frequently used for the treatment of hypercholesterolemia and for the prevention of morbidity and mortality associated with cardiovascular disease. Statins improved bone health status in intact and ovariectomised rodents following high clinically intolerable oral doses. However, this beneficial effect of statins could not be significantly demonstrated in humans. The reason behind this discrepancy might be due to the safety and bioavailability of the currently used oral statins. Vitamin E, especially the tocotrienols at the dose 60 mg/kg/day provided significant antiosteoporotic effects in different animal models of osteoporosis. The use of the aforementioned dose of tocotrienols was shown to be safe in both humans and animals. Enhancement of bone formation and reduction of bone resorption were achieved more effectively by a combination of tocotrienols and statins than by either treatment when supplemented separately at clinically tolerable doses. Therefore, the adverse effects associated with high statin doses might be avoided with the coadministration of tocotrienols. Moreover, the combination therapy strategy might be useful for patients who are at high risk of osteoporosis, cardiovascular events and hypercholesterolaemia.
  13. Abdul-Majeed S, Mohamed N, Soelaiman IN
    PMID: 22927884 DOI: 10.1155/2012/960742
    Statins are HMGCoA reductase inhibitors and had been demonstrated to stimulate bone formation in rodents after high oral doses. Observational studies on patients treated with oral statins were varied. Delta-tocotrienol had been found to stimulate the cleavage of HMGCoA reductase and inhibit its activity. Tocotrienols were found to have both catabolic and anabolic effects on bone in different animal models of osteoporosis. The current study aimed to ascertain the effects of delta-tocotrienol and lovastatin combination on biochemical and static bone histomorphometric parameters in a postmenopausal rat model at clinically tolerable doses. 48 Sprague Dawley female rats were randomly divided into 6 groups: (1) baseline control group; (2) sham-operated control group; (3) ovariectomised control group; (4) ovariectomised and 11 mg/kg lovastatin; (5) ovariectomised and 60 mg/kg delta-tocotrienol; (6) ovariectomised and 60 mg/kg delta-tocotrienol + 11 mg/kg lovastatin. These treatments were given daily via oral gavage for 8 weeks. Delta-tocotrienol plus lovastatin treatment significantly increased bone formation and reduced bone resorption compared to the other groups. Therefore, the combined treatment may have synergistic or additive effects and have the potential to be used as an antiosteoporotic agent in patients who are at risk of both osteoporosis and hypercholesterolemia, especially in postmenopausal women.
  14. Abd Manan N, Mohamed N, Shuid AN
    PMID: 22956976 DOI: 10.1155/2012/680834
    Oxidative stress and apoptosis can disrupt the bone formation activity of osteoblasts which can lead to osteoporosis. This study was conducted to investigate the effects of γ-tocotrienol on lipid peroxidation, antioxidant enzymes activities, and apoptosis of osteoblast exposed to hydrogen peroxide (H(2)O(2)). Osteoblasts were treated with 1, 10, and 100 μM of γ-tocotrienol for 24 hours before being exposed to 490 μM (IC(50)) H(2)O(2) for 2 hours. Results showed that γ-tocotrienol prevented the malondialdehyde (MDA) elevation induced by H(2)O(2) in a dose-dependent manner. As for the antioxidant enzymes assays, all doses of γ-tocotrienol were able to prevent the reduction in SOD and CAT activities, but only the dose of 1 μM of GTT was able to prevent the reduction in GPx. As for the apoptosis assays, γ-tocotrienol was able to reduce apoptosis at the dose of 1 and 10 μM. However, the dose of 100 μM of γ-tocotrienol induced an even higher apoptosis than H(2)O(2). In conclusion, low doses of γ-tocotrienol offered protection for osteoblasts against H(2)O(2) toxicity, but itself caused toxicity at the high doses.
  15. Nessa F, Ismail Z, Karupiah S, Mohamed N
    J Chromatogr Sci, 2005 Sep;43(8):416-20.
    PMID: 16212782
    A selective and sensitive reversed-phase (RP) high-performance liquid chromatographic method is developed for the quantitative analysis of five naturally occurring flavonoids of Blumea balsamifera DC, namely dihydroquercetin-7,4'-dimethyl ether (DQDE), blumeatin (BL), quercetin (QN), 5,7,3',5'-tetrahydroxyflavanone (THFE), and dihydroquercetin-4'-methyl ether (DQME). These compounds have been isolated using various chromatographic methods. The five compounds are completely separated within 35 min using an RP C18, Nucleosil column and with an isocratic methanol-0.5% phosphoric acid (50:50, v/v) mobile phase at the flow rate of 0.9 mL/min. The separation of the compounds is monitored at 285 nm using UV detection. Identifications of specific flavonoids are made by comparing their retention times with those of the standards. Reproducibility of the method is good, with coefficients of variation of 1.48% for DQME, 2.25% for THFE, 2.31% for QN, 2.23% for DQDE, and 1.51% for BL. The average recoveries of pure flavonoids upon addition to lyophilized powder and subsequent extraction are 99.8% for DQME, 99.9% for THFE, 100.0% for BL, 100.6% for DQDE, and 97.4% for QN.
  16. Perumal S, Mahmud R, Mohamed N
    PMID: 30108657 DOI: 10.1155/2018/5713703
    Pseudomonas aeruginosa is naturally resistant to many classes of antipseudomonal antibiotics due to the species ability to easily acquire resistance. Plant-based antibacterial agent in combination with the existing antibiotic proposes an alternative treatment regimen for the eradication of resistant bacterial infections. The antibacterial effects of the isolated epicatechin 3-gallate compound from Euphorbia hirta in combination with cefepime were investigated in vitro against resistant P. aeruginosa. The fractional inhibitory concentration index of the combination was determined using checkerboard broth microdilution method. Epicatechin 3-gallate combined with cefepime had produced synergistic effect against P. aeruginosa (with average FIC index of 0.24). The MIC of epicatechin 3-gallate was effectively reduced to MIC/4, MIC/8, MIC/16, and MIC/32 in the presence of cefepime. Time-kill study of epicatechin 3-gallate combined with cefepime exhibited remarkable bactericidal activity where the eradication of P. aeruginosa occurred within 4 h of treatment. Scanning electron micrographs revealed apparent cell membrane damage and leakage of cytoplasmic contents from P. aeruginosa cells which eventually led to the cell lysis after the combination treatment of epicatechin 3-gallate and cefepime. The potential of epicatechin 3-gallate to act synergistically with cefepime against clinically resistant P. aeruginosa strain possibly will maximize the successful outcomes when choosing empirical antibiotic treatment in hospitals or health care institutions.
  17. Mohamed N, Mohd Zin F, Mohd Yusoff SS
    Malays Fam Physician, 2017;12(2):29-31.
    PMID: 29423128
    Introduction: The association of myasthenia gravis (MG) with other autoimmune diseases including autoimmune thyroid disease (ATD) is well recognised, although rare. The occurrence of both diseases can occur in two ways: either disease preceding the other, or concurrently. The presentation of MG in association with ATD can range from ocular to generalised disease.

    Case Summary: A 26-year-old Malay female with persistent hyperthyroidism secondary to Hashimoto's thyroiditis in multinodular goitre was diagnosed with generalised MG after 2 years. She presented with right eye ptosis (ocular) and difficulty in swallowing and chewing (bulbar). The diagnosis of MG was confirmed by fatigability testing, electromyography and the presence of AChR antibodies. Her symptoms showed improvement with pyridostigmine (Mestinon) 60 mg 6-hourly. Her antithyroid drug was tapered down according to her thyroid function test. Throughout a year of follow-ups, her hyperthyroidism and fatigability symptoms improved with treatment. She was later counselled for total thyroidectomy and thymectomy.

    Conclusion: Myasthenia gravis and hyperthyroidism may present with similar symptoms such as dysphagia due to neuromuscular weakness or fatigue. When the diseases occur together, one of the diagnoses may be missed. Therefore, the occurrence of new symptoms in a patient with underlying ATD should should trigger the early identification of other autoimmune diseases by primary care doctors.
  18. Che Mohamed N, Moey SF, Lim BC
    Asian Pac J Cancer Prev, 2019 09 01;20(9):2865-2873.
    PMID: 31554389 DOI: 10.31557/APJCP.2019.20.9.2865
    Background: Early detection of breast cancer is essential in improving overall women’s health. The researchers
    sought to develop a comprehensive measure that combined the basic components of the health belief model (HBM)
    with a focus on breast self-examination (BSE) and screening mammogram amongst women. Methods: Questionnaire
    items were developed following a review of relevant literature of HBM on BSE and screening mammogram. The
    sampling frame for the study was Malaysian women aged 35 to 70 years old, living in Kuantan, Pahang and able to
    read or write in Bahasa Malaysia or English. As such, 103 women were randomly selected to participate in the study.
    Tests of validity using exploratory factor analysis (EFA) and reliability were subsequently performed to determine the
    psychometric properties of the questionnaire. Results: The EFA revealed nine factors (self-efficacy of mammogram,
    perceived barriers of BSE and mammogram, perceived susceptibility of breast cancer, perceived severity of breast
    cancer, cues to action for mammogram screening, perceived benefits of BSE, health motivation, perceived benefits
    of mammogram and self-efficacy of BSE) containing 54 items that jointly accounted for 74.2% of the observed
    variance. All nine factors have good internal consistency with Cronbach’s alpha ≥ 0.8. Fifty-four items remained in
    the final questionnaire after deleting 13 problematic items. The scale also showed good convergent and discriminant
    validity. Conclusion: The findings showed that the designed questionnaire was a valid and reliable instrument for the
    study involving women in Kuantan, Pahang. The instrument can help to assess women’s beliefs on BSE adoption and
    mammogram screening in health care practice and research.
  19. Mohamed NA, Mansur FAF, Abdul Rahman N
    Malays J Pathol, 2020 Apr;42(1):107-110.
    PMID: 32342938
    INTRODUCTION: Malaysia declared its intent to eliminate malaria by 2020, with a phased goal of achieving zero local transmission. Nonetheless, Malaysia is highl susceptible to malaria importation due to geographical proximity to high-burden countries e.g. Thailand, Myanmar and high influx of foreign workers and students from Asia and Africa.

    CASE SERIES: We accumulated all malaria cases diagnosed in a tertiary hospital within a period of two years. Three cases were reported, where all of the patients were foreigners with recent travel history to African countries. All of them were infected by P. falciparum, responded to treatment and discharged well.

    DISCUSSION: This case series highlighted the importance of acquiring recent travel history during history taking and having a high index of suspicions on malaria when dealing with feverish patients originated particularly from African countries.

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