Displaying publications 1 - 20 of 265 in total

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  1. Jabborova D, Annapurna K, Al-Sadi AM, Alharbi SA, Datta R, Zuan ATK
    Saudi J Biol Sci, 2021 Oct;28(10):5490-5499.
    PMID: 34588859 DOI: 10.1016/j.sjbs.2021.08.016
    Drought is a major abiotic factor limiting plant growth and crop production. There is limited information on effect of interaction between biochar and Arbuscular mycorrhizal fungi (AMF) on okra growth, root morphological traits and soil enzyme activities under drought stress. We studied the influence of biochar and AMF on the growth of Okra (Abelmoschus esculentus) in pot experiments in a net house under drought condition. The results showed that the biochar treatment significantly increased plant growth (the plant height by 14.2%, root dry weight by 30.0%) and root morphological traits (projected area by 22.3% and root diameter by 22.7%) under drought stress. In drought stress, biochar treatment significantly enhanced the chlorophyll 'a' content by 32.7%, the AMF spore number by 22.8% and the microbial biomass as compared to the control. Plant growth parameters such as plant height, shoot and root dry weights significantly increased by AMF alone, by 16.6%, 21.0% and 40.0% respectively under drought condition. Other plant biometrics viz: the total root length, the root volume, the projected area and root diameter improved significantly with the application of AMF alone by 38.3%, 60.0%,16.8% and 15.9% respectively as compared with control. Compared to the control, AMF treatment alone significantly enhanced the total chlorophyll content by 36.6%, the AMF spore number by 39.0% and the microbial biomass by 29.0% under drought condition. However, the highest values of plant growth parameters (plant height, shoot dry weight, root dry weight) and root morphological traits (the total root length, root volume, projected area, root surface area) were observed in the combined treatment of biochar and AMF treatment viz: 31.9%, 34.2%, 60.0% and 68.6%, 66.6%, 45.5%, 41.8%, respectively compared to the control under drought stress. The nitrogen content, total chlorophyll content and microbial biomass increased over un-inoculated control. The soil enzymes; alkaline phosphatase, dehydrogenase and fluorescein diacetate enzyme activities significantly increased in the combined treatment by 55.8%, 68.7% and 69.5%, respectively as compared to the control under drought stress. We conclude that biochar and AMF together is potentially beneficial for cultivation of okra in drought stress conditions.
  2. Al-Jarallah M, Rajan R, Saber AA, Pan J, Al-Sultan AT, Abdelnaby H, et al.
    EJHaem, 2021 Aug;2(3):335-339.
    PMID: 34226901 DOI: 10.1002/jha2.195
    This study is to estimate in-hospital mortality in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients stratified by hemoglobin (Hb) level. Patients were stratified according to hemoglobin level into two groups, that is, Hb <100 g/L and Hb >100 g/L. A total of 6931 patients were included. Of these, 6377 (92%) patients had hemoglobin levels >100 g/L. The mean age was 44 ± 17 years, and 66% of the patients were males. The median length of overall hospital stay was 13 days [2; 31]. The remaining 554 (8%) patients had a hemoglobin level <100 g/L. Overall mortality was 176 patients (2.54%) but was significantly higher in the group with hemoglobin levels <100 g/L (124, 22.4%) than in the group with hemoglobin levels >100 g/L (52, 0.82%). Risk factors associated with increased mortality were determined by multivariate analysis. The Kaplan-Meier survival analysis showed hemoglobin as a predictor of mortality. Cox proportional hazards regression coefficients for hemoglobin for the HB ≤ 100 category of hemoglobin were significant, B = 2.79, SE = 0.17, and HR = 16.34, p 
  3. Geiser DM, Al-Hatmi AMS, Aoki T, Arie T, Balmas V, Barnes I, et al.
    Phytopathology, 2021 Jul;111(7):1064-1079.
    PMID: 33200960 DOI: 10.1094/PHYTO-08-20-0330-LE
    Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user's needs and established successful practice. In 2013, the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus Fusarium into seven genera, including the FSSC described as members of the genus Neocosmospora, with subsequent justification in 2018 based on claims that the 2013 concept of Fusarium is polyphyletic. Here, we test this claim and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a genus Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students, and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species described as genus Neocosmospora were recombined in genus Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural, and practical taxonomic option available.
  4. Al-Qaim FF, Abdullah MP, Othman MR, Latip J, Zakaria Z
    J Chromatogr A, 2014 Jun 6;1345:139-53.
    PMID: 24768127 DOI: 10.1016/j.chroma.2014.04.025
    An analytical method that facilitated the analysis of 11 pharmaceuticals residue (caffeine, prazosin, enalapril, carbamazepine, nifedipine, levonorgestrel, simvastatin, hydrochlorothiazide, gliclazide, diclofenac-Na, and mefenamic acid) with a single pre-treatment protocol was developed. The proposed method included an isolation and concentration procedure using solid phase extraction (Oasis HLB), a separation step using high-performance liquid chromatography, and a detection procedure that applies time-of-flight mass spectrometry. The method was validated for drinking water (DW), surface water (SW), sewage treatment plant (STP) influent and effluent, and hospital (HSP) influent and effluent. The limits of quantification were as low as 0.4, 1.6, 5, 3, 2.2 and 11 ng/L in DW, SW, HSP influent and effluent, STP effluent, and STP influent, respectively. On average, good recoveries higher than 75% were obtained for most of the target analytes in all matrices. Matrix effect was evaluated for all samples matrices. The proposed method successfully determined and quantified the target compounds in raw and treated wastewater of four STPs and three hospitals in Malaysia, as well as in two SW sites. The results showed that a number of the studied compounds pose moderate to high persistency in sewage treatment effluents as well as in the recipient rivers, namely; caffeine, simvastatin, and hydrochlorothiazide. Ten out of 11 compounds were detected and quantified in 13 sampling points. Caffeine was detected with the highest level, with concentrations reaching up to 9099 ng/L in STP influent.
  5. M Sultan S, Tso CP, Sopian K, K Ajeel R, Sobayel K, Ibrahim A, et al.
    Heliyon, 2023 Nov;9(11):e21294.
    PMID: 37885726 DOI: 10.1016/j.heliyon.2023.e21294
    The photovoltaic module (PV) enhancer is a technology used for improving the PV performance. Recently, much research has been conducted to propose new concepts of PV enhancer such as coolers and reflectors. The PV enhancer performance is assessed by the common existing methods available in the literature, which solely depends on total exergy or energy, volume, area, weight and the manufacturing cost. These assessment methods are useful but cannot assess the PV enhancer's performance when considering the lifespan parameter. Hence, this study is intended to solve the current problem by linking the lifespan parameter into the existing methods by proposing three enhanced assessment methods: yield times lifespan per cost per area, yield times lifespan per cost per volume and yield times lifespan per cost per weight. The PV enhancer with the highest values of these factors will have the optimum performance. The influential parameters and limitations of the enhanced assessment methods are investigated. It is shown that the proposed methods can assess and classify the performance of the PV enhancer with different models when the lifespan is considered in the analysis. These assessment approaches can be applied by manufacturers and designers of PV enhancers.
  6. Mustafa AD, Kalyanasundram J, Sabidi S, Song AA, Abdullah M, Abdul Rahim R, et al.
    BMC Biotechnol, 2019 05 14;19(1):27.
    PMID: 31088425 DOI: 10.1186/s12896-019-0522-x
    BACKGROUND: The current limitations of conventional BCG vaccines highlights the importance in developing novel and effective vaccines against tuberculosis (TB). The utilization of probiotics such as Lactobacillus plantarum for the delivery of TB antigens through in-trans surface display provides an effective and safe vaccine approach against TB. Such non-recombinant probiotic surface display strategy involves the fusion of candidate proteins with cell wall binding domain such as LysM, which enables the fusion protein to anchor the L. plantarum cell wall externally, without the need for vector genetic modification. This approach requires sufficient production of these recombinant fusion proteins in cell factory such as Escherichia coli which has been shown to be effective in heterologous protein production for decades. However, overexpression in E. coli expression system resulted in limited amount of soluble heterologous TB-LysM fusion protein, since most of it are accumulated as insoluble aggregates in inclusion bodies (IBs). Conventional methods of denaturation and renaturation for solubilizing IBs are costly, time-consuming and tedious. Thus, in this study, an alternative method for TB antigen-LysM protein solubilization from IBs based on the use of non-denaturating reagent N-lauroylsarcosine (NLS) was investigated.

    RESULTS: Expression of TB antigen-LysM fusion genes was conducted in Escherichia coli, but this resulted in IBs deposition in contrast to the expression of TB antigens only. This suggested that LysM fusion significantly altered solubility of the TB antigens produced in E. coli. The non-denaturing NLS technique was used and optimized to successfully solubilize and purify ~ 55% of the recombinant cell wall-anchoring TB antigen from the IBs. Functionality of the recovered protein was analyzed via immunofluorescence microscopy and whole cell ELISA which showed successful and stable cell wall binding to L. plantarum (up to 5 days).

    CONCLUSION: The presented NLS purification strategy enables an efficient and rapid method for obtaining higher yields of soluble cell wall-anchoring Mycobacterium tuberculosis antigens-LysM fusion proteins from IBs in E. coli.

  7. Mustafa AD, Kalyanasundram J, Sabidi S, Song AA, Abdullah M, Abdul Rahim R, et al.
    BMC Biotechnol, 2018 10 11;18(1):63.
    PMID: 30309359 DOI: 10.1186/s12896-018-0461-y
    BACKGROUND: Tuberculosis is one of the most common and deadliest infectious diseases worldwide affecting almost a third of the world's population. Although this disease is being prevented and controlled by the Bacille Calmette Guérin (BCG) vaccine, the protective efficacy is highly variable and substandard (0-80%) in adults. Therefore, novel and effective tuberculosis vaccine that can overcome the limitations from BCG vaccine need to be developed.

    RESULTS: A novel approach of utilizing an in-trans protein surface display system of Lactobacillus plantarum carrying and displaying combination of Mycobacterium tuberculosis subunit epitope antigens (Ag85B, CFP-10, ESAT-6, Rv0475 and Rv2031c) fused with LysM anchor motif designated as ACERL was constructed, cloned and expressed in Esherichia coli Rossetta expression host. Subsequently the binding capability of ACERL to the cell wall of L. plantarum was examined via the immunofluorescence microscopy and whole cell ELISA where successful attachment and consistent stability of cell wall binding up to 4 days was determined. The immunization of the developed vaccine of L. plantarum surface displaying ACERL (Lp ACERL) via the oral route was studied in mice for its immunogenicity effects. Lp ACERL immunization was able to invoke significant immune responses that favor the Th1 type cytokine response of IFN-γ, IL-12 and IL-2 as indicated by the outcome from the cytokine profiling of spleen, lung, gastrointestinal tract (GIT), and the re-stimulation of the splenocytes from the immunized mice. Co-administration of an adjuvant consisting of Lactococcus lactis secreting mouse IL-12 (LcIL-12) with Lp ACERL was also investigated. It was shown that the addition of LcIL-12 was able to further generate significant Th1 type cytokines immune responses, similar or better than that of Lp ACERL alone which can be observed from the cytokine profiling of the immunized mice's spleen, lung and GIT.

    CONCLUSIONS: This study represents a proof of concept in the development of L. plantarum as a carrier for a non-genetically modified organism (GMO) tuberculosis vaccine, which may be the strategy in the future for tuberculosis vaccine development.

  8. Aziz ME, Yusof NR, Abdullah MS, Yusof AH, Yusof MI
    Singapore Med J, 2005 Aug;46(8):426-8.
    PMID: 16049615
    Persistent sciatic artery is a very uncommon embryological vascular variant. This case report highlights this rare vascular anomaly, diagnostic difficulty, complication and subsequent treatment in a 43-year-old man who presented with sudden onset of right leg pain for a few hours. He was unable to walk because of pain and numbness. Emergency right lower limb angiogram showed a large aneurysm that was initially thought to arise from the right common femoral artery, associated with thrombus formation within the right popliteal artery. A below knee amputation was performed due to worsening ischaemia of the right leg. The persistent right sciatic artery was later obliterated using percutaneous stenting and endovascular grafting, with deployment of two wallstents.
  9. Husbani MAR, Shuhada JM, Hamid AIA, Suardi KPS, Abdullah MS, Latif AZA, et al.
    Med J Malaysia, 2021 05;76(3):360-368.
    PMID: 34031335
    INTRODUCTION: The effective connectivity (EC) when the brain is resting and how a neuronal system exerts influence over other regions of the brain, in different groups of subjects are still being investigated. Limited information was seen about the relationship between precuneus (PRE) which is a wellknown resting state hub with supramarginal gyrus (SMG) in healthy subjects (HS) and temporal lobe epilepsy (TLE) participants.

    MATERIALS AND METHODS: Fourteen HS and 14 TLE patients with age and gender matched underwent resting state functional magnetic resonance imaging (rsfMRI) scanning using a 3-Tesla MRI machine to investigate the EC and percentage of amplitude fluctuation (PerAF) involving SMG and PRE. The rsfMRI data were analysed using Statistical Parametric Mapping (SPM12) and Spectral Dynamic Causal Modelling (spDCM) from which causal models were specified, estimated and inferred.

    RESULTS: Model with bidirectional connections between PRE and SMG was chosen as the winning model. The EC from PRE to SMG is positive but the EC from SMG to PRE is negative in both hemispheres and in HS and TLE. Based on the findings from the EC analysis, there is an excitatory effect shown by PRE to SMG connection indicating a dominant role of PRE over SMG in both groups.

    CONCLUSION: There is important evidence showing that PRE might also have influence on areas outside resting state network and the influence changes in the presence of brain abnormality.

  10. Amini P, Abdullah M, Seng LS, Karunakaran T, Hani N, Bakar SA, et al.
    Int Forum Allergy Rhinol, 2016 Jun;6(6):624-30.
    PMID: 26919193 DOI: 10.1002/alr.21442
    BACKGROUND: The number of available reports regarding the influence of ethnicity on clinical features of allergic rhinitis (AR), especially disease severity in tropical climates, is limited. We aimed to compare clinical parameters and disease severity in AR patients of different ethnicities.

    METHODS: Malay, Chinese, and Indian AR patients (n = 138) with confirmed sensitivity to Dermatophagoides pteronyssinus, Dematophagoides farinae, and Blomia tropicalis were tested for mite-specific immunoglobulin E (sIgE) levels. A detailed questionnaire was used to collect data on nasal symptom score (NSS), ocular symptom score (OSS), sum of symptoms score (SSS), quality of life score (QLS), symptomatic control score (SCS), and total sum of scores (TSS) and correlate the derived data with patients' demography, mite-polysensitivity, and sIgE levels.

    RESULTS: AR-related symptoms were most severe in Malays and least in Chinese (p < 0.01). Age (r = 0.516 to 0.673, p < 0.05) and duration of AR (r = 0.635 to 0.726, p < 0.01) correlated positively with severity domains (NSS, SSS, QLS, and TSS) in Chinese. Duration of concurrent allergies was highest in Malays (p < 0.05). Polysensitivity predicted increased sIgE levels in Malays (r = 0.464 to 0.551, p < 0.01) and Indians (r = 0.541 to 0.645, p < 0.05) but affected NSS, SSS, and TSS only in Indians (r = 0.216 to 0.376, p < 0.05). sIgE levels were lowest among Chinese but correlated strongly with NSS, OSS, SSS, and TSS (r = 0408 to 0.898, p < 0.05).

    CONCLUSION: Clinical parameters in AR may be influenced by race. Symptoms were most severe among Malays but did not correlate with other variables examined. Although Indian ethnicity did not impact disease severity, duration of concurrent allergies and mite-polysensitivity was associated with more severe disease. Age, duration of disease, and sIgE levels may be useful indicators of disease severity in Chinese.

  11. Aldubai SAR, Aljohani AM, Alghamdi AG, Alghamdi KS, Ganasegeran K, Yenbaawi AM
    J Family Med Prim Care, 2019 02;8(2):657-662.
    PMID: 30984690 DOI: 10.4103/jfmpc.jfmpc_268_18
    Background and Aim: Burnout is a common problem for interns and residents. It has been associated with physical and mental health of health care providers as well as low job satisfaction and medical errors. Few studies have investigated this problem among residents. This study aimed to determine the prevalence of burnout and its associated factors among family residents in Al Madina city, Saudi Arabia.

    Materials and Methods: This cross-sectional study was conducted among 75 residents in the family medicine residency programs in Al Madina, Saudi Arabia. A self-administered questionnaire was used that includes questions on sociodemographic characteristics and sources of stress and burnout. T test, analysis of variance (ANOVA) test, and multiple linear regression analysis were employed.

    Results: Majority were female (54.7%) and aged 26 to 30 years (84.0%). The significant predictors of burnout in the final model were "tests/examinations" (P = 0.014), "large amount of content to be learnt" (P = 0.016), "unfair assessment from superiors" (P = 0.001), "work demands affect personal/home life" (P = 0.001), and "lack of support from superiors" (P = 0.006).

    Conclusion: Burnout is present among family medicine residents at a relatively high percentage. This situation is strongly triggered by work-related stressors, organizational attributes, and system-related attributes, but not socio-demographics of the respondents. Systemic changes to relieve the workload of family medicine residents are recommended to promote effective management of burnout.

  12. Gwee KA, Lee WW, Ling KL, Ooi CJ, Quak SH, Dan YY, et al.
    J Gastroenterol Hepatol, 2018 Oct;33(10):1707-1716.
    PMID: 29697855 DOI: 10.1111/jgh.14268
    The concept of consuming microorganisms in the treatment of a medical condition and in health maintenance has gained much attraction, giving rise to an abundance of medical claims and of health supplements. This study identified relevant clinical questions on the therapeutic use of probiotics and reviewed the literature in irritable bowel syndrome, inflammatory bowel disease, impaired intestinal immunity, liver disease, intestinal infections, and common childhood digestive disorders. Statements were developed to address these clinical questions. A panel of experienced clinicians was tasked to critically evaluate and debate the available data. Both consensus and contentious statements are presented to provide to clinicians a perspective on the potential of probiotics and importantly their limitations.
  13. Ghoshal UC, Gwee KA, Chen M, Gong XR, Pratap N, Hou X, et al.
    J Neurogastroenterol Motil, 2015 Jan 1;21(1):83-92.
    PMID: 25537673 DOI: 10.5056/jnm14045
    The development-processes by regional socio-cultural adaptation of an Enhanced Asian Rome III questionnaire (EAR3Q), a cultural adaptation of the Rome III diagnostic questionnaire (R3DQ), and its translation-validation in Asian languages are presented. As English is not the first language for most Asians, translation-validation of EAR3Q is essential. Hence, we aimed to culturally adapt the R3DQ to develop EAR3Q and linguistically validate it to show that the EAR3Q is able to allocate diagnosis according to Rome III criteria.
  14. Asad M, Saba N, Asiri AM, Jawaid M, Indarti E, Wanrosli WD
    Carbohydr Polym, 2018 Jul 01;191:103-111.
    PMID: 29661297 DOI: 10.1016/j.carbpol.2018.03.015
    TEMPO-oxidize nanocellulose (TONC) suspension has been obtained from total chlorine free (TCF) oil palm empty-fruit-bunches (OPEFB) pulp using 4-acetamido-TEMPO (2,2,6,6-tetramethyl piperidin-1-oxyl) mediated oxidation with sodium hypochlorite and sodium bromide in water at 25 °C and pH 10. TONC suspension with varied content from 0.5 to 6% (w/w) reinforced polyvinyl alcohol (PVA) polymer based nanocomposite films were prepared by the casting method. The structural interaction between the TONC and PVA was characterized by the Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that the 4% (w/w) TONC content reinforced nanocomposite exhibited the highest tensile strength and modulus with an increase of 122% and 291% respectively, compared to PVA while the elongation at break decreased about 42.7%. Thermal stability of PVA based nanocomposite films was improved after incorporation of TONC. Incorporation of TONC in PVA film increases its crystallinity due to strongly linking between the hydroxyl groups of materials however considerable decreases beyond 2 wt% loading are observed. TONC incorporation beyond 2 wt% also reduces the melting temperature peaks and enthalpy of nanocomposite films. FT-IR spectra, NMR and SEM indicate that there is interaction between the TONC and PVA.
  15. Zulkeflee RH, Hassan MN, Hassan R, Saidin NIS, Zulkafli Z, Ramli M, et al.
    Transfus Apher Sci, 2023 Jun;62(3):103658.
    PMID: 36805153 DOI: 10.1016/j.transci.2023.103658
    Acute hemolytic transfusion reaction following ABO-incompatible platelet transfusion: two case reports An ideal platelet transfusion should provide ABO identical platelet concentrate, and cross match compatibility is not routinely performed in the standard practices. However, ABO non identical platelet transfusions are not uncommon with the limited resources and short shelf life of platelet concentrate. Though rare, acute hemolytic transfusion reaction (AHTR) may occur following minor ABO-incompatible platelet transfusion. Here, we report two cases of thrombocytopenic patients (one child and one adult) type as Group B RhD positive and received Group O RhD positive platelet transfusions. Both patients experienced an AHTR evidenced by a drop in hemoglobin level, spherocytosis and small agglutinations on the blood film, and positive direct Coombs test. They were treated symptomatically, recovered and discharged well post-event without any morbidity. No anti-B isohemagglutinins titer were done to confirm the high titer of the antibody in the platelet donors. Our cases highlighted the importance of ABO-compatible platelet transfusion, especially to children and those vigilant groups of patients.
  16. Yip CH, Taib NA, Abdullah MM, Wahid I
    Med J Malaysia, 2000 Sep;55(3):308-10.
    PMID: 11200709
    Presentation of breast cancer during pregnancy is a rare situation and one that requires a multidisciplinary approach involving an obstetrician, surgeon and oncologist. Management should be along the same principles as in non-pregnant patients and delay is not justifiable. Mastectomy and axillary clearance is the best option, followed by chemotherapy, which is safe after the first trimester. Radiation if required should be delayed until after delivery of the baby. We present here our experience with 6 patients who presented with breast cancer during pregnancy. Five patients refused any treatment until after delivery, while one underwent only a mastectomy and axillary clearance. The outcome was poor; all of them died between 14 months and 52 months. The poor outcome probably reflects the late stage at presentation in four of the patients (State 3 and 4) rather than the delay in treatment, while delay in treatment in the two who presented with early cancer (Stage 1 and 2) led to a more advanced stage after delivery.
  17. Ramasamy, R., Krishna, K., Maqbool, M., Vellasamy, S., Sarmadi, V. H., Abdullah, M., et al.
    MyJurnal
    Objective: Mesenchymal stem cells (MSC) are multipotent, non-haematopoietic stem cells that are
    capable of differentiating into different varieties of mature cell types such as osteoblasts, chondrocytes, adipocytes, and myoblasts. There is abundant evidence showing that MSC not only affect the differentiation of haematopoietic progenitors, but also the function of mature cells like lymphocytes and neutrophils. However the effect of MSC on neutrophil function and its responses is not well studied. Therefore, this study was conducted to assess the effect of MSC on neutrophil nitric oxide production. Method: Neutrophils from heparanised venous blood were isolated using Ficoll-Hypaque density gradient centrifugation followed by Dextran sedimentation and red blood cell (RBC) lysis. Isolated neutrophils were on average of 97% purity as determined by morphologic analysis. MSC were generated from human bone marrow and characterised by immunophenotyping (monoclonal antibodies CD105, CD73 and CD34) using a flowcytometer. In order to test the effects of MSC on neutrophil function, isolated neutrophils were co-cultured in the presence or absence of MSC at different ratios for 24 and 48 hours. The amount of nitric oxide released was used as an indication of oxidative burst and measured using the Griess assay. Result: The results indicate that MSC neither elevate the NO level when cocultured with resting neutrophils nor alone. However MSC profoundly inhibit the secretion of nitric oxide in PMA stimulated neutrophils after 24hr of incubation. Conclusion: MSC exert an immunomodulatory effect on neutrophil by suppressing neutrophil oxidative burst in vitro.
  18. Abdullah M, Chai PS, Chong MY, Tohit ER, Ramasamy R, Pei CP, et al.
    Cell Immunol, 2012;272(2):214-9.
    PMID: 22078320 DOI: 10.1016/j.cellimm.2011.10.009
    Differences in gender immune response have resulted in differences in immune protection and susceptibility to inflammatory diseases. Cultured peripheral blood mononuclear cells (PBMC) are widely used in immunomodulation studies, yet the influence of gender is usually not considered. We examined the effect of in vitro culture and phytohaemagglutinin (PHA) stimulation on PBMC lymphocyte subsets using flowcytometry. Full blood counts of whole blood showed higher levels of lymphocyte in male subjects. Lymphocyte subsets enumeration revealed higher NK cell counts in males and higher B cells in females. Cultured PBMC resulted in significant increases in B and total T cell percentages among females and NK cells among males. PHA stimulated significantly increased percentages of NK and total T cells in males and total activated T cells (CD69+) in females. Our results showed significant gender differences in lymphocyte subsets in cultured conditions. This may affect experimental outcome.
  19. Tan SW, Ramasamy R, Abdullah M, Vidyadaran S
    Cell Immunol, 2011;271(2):205-9.
    PMID: 21839427 DOI: 10.1016/j.cellimm.2011.07.012
    Anti-inflammatory actions of the vitamin E fragment tocotrienol have not been described for microglia. Here, we screened palm α-, γ- and δ-tocotrienol isoforms and Tocomin® 50% (contains spectrum of tocotrienols and tocopherols) for their ability to limit nitric oxide (NO) production by BV2 microglia. Microglia were treated with varying doses of tocotrienols for 24h and stimulated with 1 μg/ml lipopolysaccharide (LPS). All tocotrienol isoforms reduced NO release by LPS-stimulated microglia, with 50 μM being the most potent tocotrienol dose. Of the isoforms tested, δ-tocotrienol lowered NO levels the most, reducing NO by approximately 50% at 48 h post-LPS treatment (p
  20. Ooi YY, Ramasamy R, Rahmat Z, Subramaiam H, Tan SW, Abdullah M, et al.
    Int Immunopharmacol, 2010 Dec;10(12):1532-40.
    PMID: 20850581 DOI: 10.1016/j.intimp.2010.09.001
    The immunoregulatory properties of mesenchymal stem cells (MSC) have been demonstrated on a wide range of cells. Here, we describe the modulatory effects of mouse bone marrow-derived MSC on BV2 microglia proliferation rate, nitric oxide (NO) production and CD40 expression. Mouse bone marrow MSC were co-cultured with BV2 cells at various seeding density ratios and activated with lipopolysaccharide (LPS). We show that MSC exert an anti-proliferative effect on microglia and are potent producers of NO when stimulated by soluble factors released by LPS-activated BV2. MSC suppressed proliferation of both untreated and LPS-treated microglia in a dose-dependent manner, significantly reducing BV2 proliferation at seeding density ratios of 1:0.2 and 1:0.1 (p
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