Displaying publications 1 - 20 of 66 in total

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  1. Fulltext Animal Model of Gestational Diabetes Mellitus with Pathophysiological Resemblance to the Human Condition Induced by Multiple Factors (Nutritional, Pharmacological, and Stress) in Rats
    Abdul Aziz SH, John CM, Mohamed Yusof NI, Nordin M, Ramasamy R, Adam A, et al.
    Biomed Res Int, 2016;2016:9704607.
    PMID: 27379252 DOI: 10.1155/2016/9704607
    This study attempts to develop an experimental gestational diabetes mellitus (GDM) animal model in female Sprague-Dawley rats. Rats were fed with high fat sucrose diet, impregnated, and induced with Streptozotocin and Nicotinamide on gestational day 0 (D0). Sleeping patterns of the rats were also manipulated to induce stress, a lifestyle factor that contributes to GDM. Rats were tested for glycemic parameters (glucose, C-peptide, and insulin), lipid profiles (total cholesterol, triglycerides, HDL, and LDL), genes affecting insulin signaling (IRS-2, AKT-1, and PCK-1), glucose transporters (GLUT-2 and GLUT-4), proinflammatory cytokines (IL-6, TNF-α), and antioxidants (SOD, CAT, and GPX) on D6 and D21. GDM rats showed possible insulin resistance as evidenced by high expression of proinflammatory cytokines, PCK-1 and CRP. Furthermore, low levels of IRS-2 and AKT-1 genes and downregulation of GLUT-4 from the initial to final phases indicate possible defect of insulin signaling. GDM rats also showed an impairment of antioxidant status and a hyperlipidemic state. Additionally, GDM rats exhibited significantly higher body weight and blood glucose and lower plasma insulin level and C-peptide than control. Based on the findings outlined, the current GDM animal model closely replicates the disease state in human and can serve as a reference for future investigations.
  2. Call for TERMIS-AP 2020 Special Issue Papers: Revolutionizing Regenerative Research Strategies Towards Precision Medicine
    Abdull Rasad MSBB, Ramasamy R
    Tissue Eng Part A, 2020 Jan;26(1-2):1-2.
    PMID: 31910352 DOI: 10.1089/ten.tea.2019.29006.cfp
  3. Call for TERMIS-AP 2020 Special Issue Papers: Revolutionizing Regenerative Research Strategies Towards Precision Medicine
    Abdull Rasad MSBB, Ramasamy R
    Tissue Eng Part A, 2020 Feb;26(3-4):111-112.
    PMID: 32073382 DOI: 10.1089/ten.tea.2019.29006.cfp2
  4. Call for TERMIS-AP 2020 Special Issue Papers: Revolutionizing Regenerative Research Strategies Towards Precision Medicine
    Abdull Rasad MSBB, Ramasamy R
    Tissue Eng Part A, 2020 Apr;26(7-8):375-376.
    PMID: 32228374 DOI: 10.1089/ten.tea.2019.29006.cfp4
  5. Call for TERMIS-AP 2020 Special Issue Papers: Revolutionizing Regenerative Research Strategies Towards Precision Medicine
    Abdull Rasad MSBB, Ramasamy R
    Tissue Eng Part A, 2020 Jun;26(11-12):583-584.
    PMID: 32552599 DOI: 10.1089/ten.tea.2019.29006.cfp6
  6. Gender effect on in vitro lymphocyte subset levels of healthy individuals
    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.
  7. Fulltext Gene transfer into the lung by nanoparticle dextran-spermine/plasmid DNA complexes
    Abdullah S, Wendy-Yeo WY, Hosseinkhani H, Hosseinkhani M, Masrawa E, Ramasamy R, et al.
    J Biomed Biotechnol, 2010;2010:284840.
    PMID: 20617146 DOI: 10.1155/2010/284840
    A novel cationic polymer, dextran-spermine (D-SPM), has been found to mediate gene expression in a wide variety of cell lines and in vivo through systemic delivery. Here, we extended the observations by determining the optimal conditions for gene expression of D-SPM/plasmid DNA (D-SPM/pDNA) in cell lines and in the lungs of BALB/c mice via instillation delivery. In vitro studies showed that D-SPM could partially protect pDNA from degradation by nuclease and exhibited optimal gene transfer efficiency at D-SPM to pDNA weight-mixing ratio of 12. In the lungs of mice, the levels of gene expression generated by D-SPM/pDNA are highly dependent on the weight-mixing ratio of D-SPM to pDNA, amount of pDNA in the complex, and the assay time postdelivery. Readministration of the complex at day 1 following the first dosing showed no significant effect on the retention and duration of gene expression. The study also showed that there was a clear trend of increasing size of the complexes as the amount of pDNA was increased, where the sizes of the D-SPM/pDNA complexes were within the nanometer range.
  8. Fulltext Generation and characterization of human Osteoarthritis Cartilage-derived Mesenchymal Stem Cells by modified sample processing and culture method
    Algraittee, Satar Jabbar Rahi, Lawal, Hamza, Boroojerdi, Mohadese Hashem, Sarmadi, Vahid Hosseinpour, Maqbool, Maryam, Fahrudin Che Hamzah, et al.
    Malaysian Journal of Medicine and Health Sciences, 2018;14(103):1-9.
    MyJurnal
    Mesenchymal stem cells (MSCs) can be isolated from different tissue sources, and show a high differentiation capacity towards osteogenic, adipogenic, chondrogenic, neurogenic and myogenic lineages upon a specific induction. Although the retrieval of MSCs from normal tissues is very straightforward, yet it could be challenging in degenerative conditions that limit the expansion of stem cells such as osteoarthritis. Thus, this study aimed to establish human MSCs culture from osteoarthritic cartilage (OA hC-MSCs) by optimising the sample processing and culture techniques. Methods: Human osteoarthritis knee cartilage samples were obtained (2-4 g) from 8 patients with a mean age of 62.75 years old during the joint replacement surgery. A conventional culture method carried along with the modified method where the period of enzyme digestion and serial plating culture procedure were incorporated. Results: The modified culture method has significantly increased the number of single cells twice after the sample processing. The time taken to form colonies and achieve confluence was also reduced when samples subjected to the modified method. The number of cell yields after passage 0 for the conventional and modified methods were 3.05±0.31 and 6.10±0.42 million cells, respectively. The adherent cells generated under these two conditions comply with criteria for MSCs in term of immunophenotyping and mesodermal differentiation. Conclusions: The current modified method enhances the production of MSCs and could be opted for samples that known to have reduced or defective stem cell pool which may impede the in vitro cell expansion.
  9. Fulltext Colostrum supplementation protects against exercise-induced oxidative stress in skeletal muscle in mice
    Appukutty M, Radhakrishnan AK, Ramasamy K, Ramasamy R, Abdul Majeed AB, Noor MI, et al.
    BMC Res Notes, 2012;5:649.
    PMID: 23173926 DOI: 10.1186/1756-0500-5-649
    This study examined the effects of bovine colostrum on exercise -induced modulation of antioxidant parameters in skeletal muscle in mice. Adult male BALB/c mice were randomly divided into four groups (control, colostrum alone, exercise and exercise with colostrum) and each group had three subgroups (day 0, 21 and 42). Colostrum groups of mice were given a daily oral supplement of 50 mg/kg body weight of bovine colostrum and the exercise group of mice were made to exercise on the treadmill for 30 minutes per day. Total antioxidants, lipid hydroperoxides, xanthine oxidase and super oxide dismutase level was assayed from the homogenate of hind limb skeletal muscle.
  10. In Vitro Blood-Brain Barrier Models for Neuroinfectious Diseases: A Narrative Review
    Badawi AH, Mohamad NA, Stanslas J, Kirby BP, Neela VK, Ramasamy R, et al.
    Curr Neuropharmacol, 2023 Dec 08.
    PMID: 38073104 DOI: 10.2174/1570159X22666231207114346
    The blood-brain barrier (BBB) is a complex, dynamic, and adaptable barrier between the peripheral blood system and the central nervous system. While this barrier protects the brain and spinal cord from inflammation and infection, it prevents most drugs from reaching the brain tissue. With the expanding interest in the pathophysiology of BBB, the development of in vitro BBB models has dramatically evolved. However, due to the lack of a standard model, a range of experimental protocols, BBB-phenotype markers, and permeability flux markers was utilized to construct in vitro BBB models. Several neuroinfectious diseases are associated with BBB dysfunction. To conduct neuroinfectious disease research effectively, there stems a need to design representative in vitro human BBB models that mimic the BBB's functional and molecular properties. The highest necessity is for an in vitro standardised BBB model that accurately represents all the complexities of an intact brain barrier. Thus, this in-depth review aims to describe the optimization and validation parameters for building BBB models and to discuss previous research on neuroinfectious diseases that have utilized in vitro BBB models. The findings in this review may serve as a basis for more efficient optimisation, validation, and maintenance of a structurally- and functionally intact BBB model, particularly for future studies on neuroinfectious diseases.
  11. Call for TERMIS-AP 2020 Special Issue Papers: Revolutionizing Regenerative Research Strategies Towards Precision Medicine
    Bin Abdull Rasad MSB, Ramasamy R
    Tissue Eng Part A, 2020 Mar;26(5-6):371-372.
    PMID: 32101503 DOI: 10.1089/ten.tea.2019.29006.cfp3
  12. Call for TERMIS-AP 2020 Special Issue Papers: Revolutionizing Regenerative Research Strategies Towards Precision Medicine
    Bin Abdull Rasad MSB, Ramasamy R
    Tissue Eng Part A, 2020 May;26(9-10):461-462.
    PMID: 32379542 DOI: 10.1089/ten.tea.2019.29006.cfp5
  13. Fulltext The efficiency of cell sorting and harvesting methods for In vitro expansion of human umbilical cord blood derived CD34+ hematopoietic stem cells
    Borojerdi, Mohadese Hashem, Maqbool, Maryam, Zuraidah Yusoff, Vidyadaran, Sharmili, Hwa, Ling King, George, Elizabeth, et al.
    Malaysian Journal of Medicine and Health Sciences, 2015;11(2):21-28.
    MyJurnal
    Introduction: During the last three decades hematopoietic stem cell transplantation (HSCT) has become a well-established treatment for many hematologic malignancies. The most important limitation for HSC transplantation is the low number of hematopoietic stem cells (HSC) that can lead to delayed engraftment or graft failures. Numerous attempts have been made to improve in vitro HSC expansion via optimization of various methods such as isolation techniques, supplementing with growth factors, utilizing stromal cells as feeder layer and other culture conditions. Objective: This project is aimed to decipher the efficiency of an isolation technique and retrieval of culture expanded HSC from feeder layer using two different harvesting methods. Materials and Methods: Hematopoietic stem cells from human umbilical cord blood were isolated via MACS mediated CD34+ double sorting. Then, the cells were cultured onto MSC feeder layer for 3 and 5 days. Culture expanded cells were harvested using two different harvesting method namely cell aspiration and trypsinization methods. Hematopoietic stem cell expansion index were calculated based on harvesting methods for each time point. Results: The numbers of HSC isolated from human umbilical cord blood were 1.64 x 106 and 1.20 x106 cells at single and double sortings respectively. Although the number of sorted cells diminished at the second sorting yet the yield of CD34+ purity has increased from 43.73% at single sorting to 81.40% at double sorting. Employing the trypsinization method, the HSC harvested from feeder layer showed a significant increase in expansion index (EI) as compared to the cell aspiration harvesting method (p≤ 0.05). However, the purity of CD34+ HSC was found higher when the cells were harvested using aspiration method (82.43%) as compared to the trypsinization method (74.13%). Conclusion: A pure population of CD34+ HSC can be retrieved when the cells were double sorted using MACS and expanded in culture after being harvested using cell aspiration method.
  14. Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSC) inhibit the proliferation of K562 (human erythromyeloblastoid leukaemic cell line)
    Fonseka M, Ramasamy R, Tan BC, Seow HF
    Cell Biol Int, 2012 Sep;36(9):793-801.
    PMID: 22335239 DOI: 10.1042/CBI20110595
    hUCB-MSC (human umbilical cord blood-derived mesenchymal stem cells) offer an attractive alternative to bone marrow-derived MSC for cell-based therapy by being less invasive a source of biological material. We have evaluated the effect of hUCB-MSC on the proliferation of K562 (an erythromyeloblastoid cell line) and the cytokine secretion pattern of hUCB-MSC. Co-culturing of hUCB-MSC and K562 resulted in inhibition of proliferation of K562 in a dose-dependent manner. However, the anti-proliferative effect was reduced in transwells, suggesting the importance of direct cell-to-cell contact. hUCB-MSC inhibited proliferation of K562, arresting them in the G0 /G1 phase. NO (nitric oxide) was not involved in the hUCB-MSC-mediated tumour suppression. The presence of IL-6 (interleukin 6) and IL-8 were obvious in the hUCB-MSC conditioned media, but no significant increase was found in 29 other cytokines. Th1 cytokines, IFNα (interferon α), Th2 cytokine IL-4 and Th17 cytokine, IL-17 were not secreted by hUCB-MSC. There was an increase in the number of hUCB-MSC expressing the latent membrane-bound form of TGFβ1 co-cultured with K562. The anti-proliferative effect of hUCB-MSC was due to arrest of the growth of K562 in the G0 /G1 phase. The mechanisms underlying increased IL-6 and IL-8 secretion and LAP (latency-associated peptide; TGFβ1) by hUCB-MSC remains unknown.
  15. 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.
  16. Fulltext Electromagnetic field exposure as a plausible approach to enhance the proliferation and differentiation of mesenchymal stem cells in clinically relevant scenarios
    Hamid HA, Sarmadi VH, Prasad V, Ramasamy R, Miskon A
    J Zhejiang Univ Sci B, 2022 Jan 15;23(1):42-57.
    PMID: 35029087 DOI: 10.1631/jzus.B2100443
    Mesenchymal stem/stromal cell (MSC)‍-based therapy has been regarded as one of the most revolutionary breakthroughs in the history of modern medicine owing to its myriad of immunoregulatory and regenerative properties. With the rapid progress in the fields of osteo- and musculoskeletal therapies, the demand for MSC-based treatment modalities is becoming increasingly prominent. In this endeavor, researchers around the world have devised new and innovative techniques to support the proliferation of MSCs while minimizing the loss of hallmark features of stem cells. One such example is electromagnetic field (EMF) exposure, which is an alternative approach with promising potential. In this review, we present a critical discourse on the efficiency, practicability, and limitations of some of the relevant methods, with insurmountable evidence backing the implementation of EMF as a feasible strategy for the clinically relevant expansion of MSCs.
  17. Directional capacity of human mesenchymal stem cells to support hematopoietic stem cell proliferation in vitro
    Hashem Boroojerdi M, Hosseinpour Sarmadi V, Maqbool M, Ling KH, Safarzadeh Kozani P, Safarzadeh Kozani P, et al.
    Gene, 2022 Feb 05;820:146218.
    PMID: 35134469 DOI: 10.1016/j.gene.2022.146218
    OBJECTIVES: Hematopoietic stem cells (HSCs) reside in a specialised microenvironment in the bone marrow, which is majorly composed of mesenchymal stem cells (MSCs) and its' derivatives. This study aimed to investigate the regulatory role of MSCs to decipher the cellular and humoral communications on HSCs' proliferation, self-renewal, and differentiation at the transcriptomic level.

    MATERIALS AND METHODS: Microarray assay was employed to analyse the gene expression profile of HSCs that imparted by MSCs during co-culture.

    RESULTS: The proliferation of human umbilical cord blood-derived HSCs (hUC-HSCs) markedly propagated when MSCs were used as the feeder layer, without disturbing the undifferentiated state of HSCs, and reduced the cell death of HSCs. Upon co-culture with MSCs, the global microarray analysis of HSCs disclosed 712 differentially expressed genes (DEGs) (561 up-regulated and 151 down-regulated). The dysregulations of various transcripts were enriched for cellular functions such as cell cycle (including CCND1), apoptosis (including TNF), and genes related to signalling pathways governing self-renewal, as well as WNT5A from the Wnt signalling pathway, MAPK, Hedgehog, FGF2 from FGF, Jak-STAT, and PITX2 from the TGF-β signalling pathway. To concur this, real-time quantitative PCR (RT-qPCR) was utilised for corroborating the microarray results from five of the most dysregulated genes.

    CONCLUSION: This study elucidates the underlying mechanisms of the mitogenic influences of MSCs on the propagation of HSCs. The exploitation of such mechanisms provides a potential means for achieving larger quantities of HSCs in vitro, thus obviating the need for manipulating their differentiation potential for clinical application.

  18. Immunomodulatory activity of polyphenols derived from Cassia auriculata flowers in aged rats
    John CM, Sandrasaigaran P, Tong CK, Adam A, Ramasamy R
    Cell Immunol, 2011;271(2):474-9.
    PMID: 21924708 DOI: 10.1016/j.cellimm.2011.08.017
    The immunomodulatory activity of Cassia auriculata (CA)-derived polyphenols was tested on aged rats. Rats (24-26 months old) were given CA polyphenols supplementation at doses of 25, 50, and 100 mg/kg for 28 days. Flow cytometry analysis of CA polyphenols-treated aged rats showed increased T and B cells percentage along with enhanced proliferation of splenocytes in both resting and LPS-stimulated cells. Increased percentage of pan T cells is further supported by an elevation of CD4+, CD8+, and CD4+CD25+ regulatory cells. In terms of innate immune cell activity, CA polyphenol supplementation reduced the oxidative burst activity of neutrophils in response to PMA and Escherichia coli activation. Our results collectively show that polyphenols derived from CA boost T cell immunity by increasing the number of T cells and its sensitivity towards stimulants and decreasing ROS production by neutrophils that could potentially harm multiple biological systems in aged individuals.
  19. Enhanced CD4+CD25+ regulatory T cells with splenic proliferation and protection against oxidative stress by nicotinamide in gestational diabetes
    John CM, Ramasamy R, Al Naqeeb G, Dhiab Al-Nuaimi AH, Adam A
    Curr Med Chem, 2012 Aug 16.
    PMID: 22934758
    Gestational diabetes mellitus (GDM) is a common complication during pregnancy. Metabolic changes in GDM affect fetal development and fetal glucose homeostasis. Several complications of diabetes are related to increased intracellular oxidative stress where prooxidants exceed antioxidant capacity. The present study was initiated to evaluate the effects of nicotinamide on CD4+CD25+ regulatory T cells (Tregs), proliferation of splenocytes, production of reactive oxygen species (ROS) by neutrophils and serum glucose levels. Changes in mRNA levels of two antioxidant genes in liver, viz, superoxide dismutase (SOD1) and catalase (CAT) were quantified with real-time PCR (QRT-PCR). Nicotinamide (50, 100 and 200 mg/kg) was supplemented p.o. to pregnant diabetic rats from days 6 through 20 of gestation. The highest dose enhanced expression of Tregs and increased splenocytes proliferation in both resting and lipopolysaccharide (LPS)-stimulated cells. Oxidative burst activity of neutrophils in response to phorbol myristate acetate (PMA), N-formyl-methionyl-leucyl-phenylalanine (FMLP) or E. coli activation was reduced. mRNA expressions of superoxide dismutase (SOD) and catalase (CAT) genes were upregulated by nicotinamide. In summary, nicotinamide boosted the immune system through stimulation of adaptive immune cells with enhancement of antioxidant defences and reduced production of ROS. Serum glucose level was normalised by nicotinamide (200 mg/kg). These findings provide evidence for usage of nicotinamide as a supplement or as adjunct to therapeutic agents in gestational diabetes and in pregnant individuals with weakened immune systems.
  20. Fulltext Mesenchymal stem cells exert anti-proliferative effect on lipopolysaccharide-stimulated BV2 microglia by reducing tumour necrosis factor-α levels
    Jose S, Tan SW, Ooi YY, Ramasamy R, Vidyadaran S
    J Neuroinflammation, 2014;11:149.
    PMID: 25182840 DOI: 10.1186/s12974-014-0149-8
    Progression of neurodegenerative diseases occurs when microglia, upon persistent activation, perpetuate a cycle of damage in the central nervous system. Use of mesenchymal stem cells (MSC) has been suggested as an approach to manage microglia activation based on their immunomodulatory functions. In the present study, we describe the mechanism through which bone marrow-derived MSC modulate the proliferative responses of lipopolysaccharide-stimulated BV2 microglia.
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