Displaying publications 1 - 20 of 66 in total

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  1. Fulltext Establishing a culture system that supports in vitro expansion of adult microglia
    Subramaniam, Hemavathy, Alireza Badiei, Ramasamy, Rajesh, Maha Abdullah, Vidyadaran, Sharmili
    Malaysian Journal of Medicine and Health Sciences, 2010;6(2):25-30.
    MyJurnal
    Introduction: The vast majority of in vitro research on microglia are based on cells isolated from
    neonatal animals (3-5 days of age). Studying microglia of adults has been limited by the lack of a suitable culture system that supports their growth. In this study, we describe a protocol for growing microglia of adults based on modifications of the technique for culturing microglia isolated from neonatal rats. Methods: Mixed glia isolated from adult rats (age range of 1 month to 3 years old) were seeded in
    culture flasks coated with poly-L-lysine. Cells were maintained in DMEM media supplemented with
    insulin-transferrin-selenium (ITS) and recombinant human macrophage colony-stimulating factor
    (M-CSF). Mild trypsinisation was carried out to isolate microglia from mixed glia culture. Results:
    Microglia cells of adult rats were successfully grown in vitro. For the expansion of adult microglia,
    it was observed that coating the cell culture flasks with poly-L-lysine was crucial to encourage cell
    adherence. The substitution of insulin in culture media with ITS was found to improve cell yield and
    reduced the number of days required for culture from 28 days to 14 days. Addition of M-CSF to cell
    culture medium, along with the improvisations described above provided the best adult microglia cell
    yield (2.91 ± 0.56 x 106 cells) compared to the technique of replating cells (0.91 ± 0.65 x 106 cells;
    p
  2. 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.
  3. 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.
  4. Inhibitory effects of palm α-, γ- and δ-tocotrienol on lipopolysaccharide-induced nitric oxide production in BV2 microglia
    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
  5. Fulltext Immunophenotype and differentiation capacity of bone marrow-derived mesenchymal stem cells from CBA/Ca, ICR and Balb/c mice
    Ooi YY, Rahmat Z, Jose S, Ramasamy R, Vidyadaran S
    World J Stem Cells, 2013 Jan 26;5(1):34-42.
    PMID: 23362438 DOI: 10.4252/wjsc.v5.i1.34
    To assess the capacity to isolate and expand mesenchymal stem cells (MSC) from bone marrow of CBA/Ca, ICR and Balb/c mice.
  6. Bone marrow-derived mesenchymal stem cells modulate BV2 microglia responses to lipopolysaccharide
    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
  7. Response Profiles of BV2 Microglia to IFN-γ and LPS Co-Stimulation and Priming
    Pan ML, Ahmad Puzi NN, Ooi YY, Ramasamy R, Vidyadaran S
    Biomedicines, 2023 Sep 27;11(10).
    PMID: 37893022 DOI: 10.3390/biomedicines11102648
    (1) Background: The latest research illustrates that microglia phenotype is not the binary 'resting' and 'activated' profiles. Instead, there is wide diversity in microglia states. Similarly, when testing different stimulation protocols for BV2 microglia, we discovered differences in the response of the cells in terms of the production of intracellular ROS (iROS), nitric oxide (NO), CD40 expression, and migratory capacity. (2) Methods: BV2 microglia were treated with single interferon gamma (IFN-γ) stimulation, LPS/IFN-γ co-stimulation, and priming with IFN-γ followed by stimulation with LPS for 24 h. The responses of BV2 microglia were then assessed using the H2DCFDA test for iROS, the Griess assay for NO, immunophenotyping for CD40/CD11b/MHC II, and migration using a transwell apparatus. (3) Results: Single stimulation with IFN-γ induced NO but not ROS in BV2 microglia. Co-stimulation with LPS200IFN-γ2.5 induced a higher iROS production (a 9.2-fold increase) and CD40 expression (28031 ± 8810.2 MFI), compared to priming with primedIFN-γ50LPS100 (a 4.0-fold increase in ROS and 16764 ± 1210.8 MFI of CD40). Co-stimulation also induced cell migration. On the other hand, priming BV2 microglia (primedIFN-γ50LPS100) resulted in a higher NO production (64 ± 1.4 µM) compared to LPS200IFN-γ2.5 co-stimulation (44 ± 1.7 µM). Unexpectedly, priming inhibited BV2 migration. (4) Conclusions: Taken together, the findings from this project reveal the ability of co-stimulation and priming in stimulating microglia into an inflammatory phenotype, and the heterogeneity of microglia responses towards different stimulating approaches.
  8. Editorial for the Special Issue: Revolutionizing Regenerative Research Strategies Toward Precision Medicine-Asia-Pacific Region
    Ramasamy R, Yahaya BH, Tan SL
    Tissue Eng Part C Methods, 2022 10;28(10):499-500.
    PMID: 36326783 DOI: 10.1089/ten.tec.2022.29035.editorial
  9. Human mesenchymal stem cells promote CD34+hematopoietic stem cell proliferation with preserved red blood cell differentiation capacity
    Lau SX, Leong YY, Ng WH, Ng AWP, Ismail IS, Yusoff NM, et al.
    Cell Biol Int, 2017 Jun;41(6):697-704.
    PMID: 28403524 DOI: 10.1002/cbin.10774
    Studies showed that co-transplantation of mesenchymal stem cells (MSCs) and cord blood-derived CD34+hematopoietic stem cells (HSCs) offered greater therapeutic effects but little is known regarding the effects of human Wharton's jelly derived MSCs on HSC expansion and red blood cell (RBC) generation in vitro. This study aimed to investigate the effects of MSCs on HSC expansion and differentiation. HSCs were co-cultured with MSCs or with 10% MSCs-derived conditioned medium, with HSCs cultured under standard medium served as a control. Cell expansion rates, number of mononuclear cell post-expansion and number of enucleated cells post-differentiation were evaluated. HSCs showed superior proliferation in the presence of MSC with mean expansion rate of 3.5 × 108 ± 1.8 × 107after day 7 compared to the conditioned medium and the control group (8.9 × 107 ± 1.1 × 108and 7.0 × 107 ± 3.3 × 106respectively, P 
  10. Fulltext Human Wharton's Jelly-Derived Mesenchymal Stem Cells Minimally Improve the Growth Kinetics and Cardiomyocyte Differentiation of Aged Murine Cardiac c-kit Cells in In Vitro without Rejuvenating Effect
    Ng WH, Yong YK, Ramasamy R, Ngalim SH, Lim V, Shaharuddin B, et al.
    Int J Mol Sci, 2019 Nov 06;20(22).
    PMID: 31698679 DOI: 10.3390/ijms20225519
    Cardiac c-kit cells show promise in regenerating an injured heart. While heart disease commonly affects elderly patients, it is unclear if autologous cardiac c-kit cells are functionally competent and applicable to these patients. This study characterised cardiac c-kit cells (CCs) from aged mice and studied the effects of human Wharton's Jelly-derived mesenchymal stem cells (MSCs) on the growth kinetics and cardiac differentiation of aged CCs in vitro. CCs were isolated from 4-week- and 18-month-old C57/BL6N mice and were directly co-cultured with MSCs or separated by transwell insert. Clonogenically expanded aged CCs showed comparable telomere length to young CCs. However, these cells showed lower Gata4, Nkx2.5, and Sox2 gene expressions, with changes of 2.4, 3767.0, and 4.9 folds, respectively. Direct co-culture of both cells increased aged CC migration, which repopulated 54.6 ± 4.4% of the gap area as compared to aged CCs with MSCs in transwell (42.9 ± 2.6%) and CCs without MSCs (44.7 ± 2.5%). Both direct and transwell co-culture improved proliferation in aged CCs by 15.0% and 16.4%, respectively, as traced using carboxyfluorescein succinimidyl ester (CFSE) for three days. These data suggest that MSCs can improve the growth kinetics of aged CCs. CCs retaining intact telomere are present in old hearts and could be obtained based on their self-renewing capability. Although these aged CCs with reduced growth kinetics are improved by MSCs via cell-cell contact, the effect is minimal.
  11. Mesenchymal stem cells facilitate cardiac differentiation in Sox2-expressing cardiac C-kit cells in coculture
    Leong YY, Ng WH, Umar Fuaad MZ, Ng CT, Ramasamy R, Lim V, et al.
    J Cell Biochem, 2019 06;120(6):9104-9116.
    PMID: 30548289 DOI: 10.1002/jcb.28186
    Stem cell therapy offers hope to reconstitute injured myocardium and salvage heart from failing. A recent approach using combinations of derived Cardiac-derived c-kit expressing cells (CCs) and mesenchymal stem cells (MSCs) in transplantation improved infarcted hearts with a greater functional outcome, but the effects of MSCs on CCs remain to be elucidated. We used a novel two-step protocol to clonogenically amplify colony forming c-kit expressing cells from 4- to 6-week-old C57BL/6N mice. This method yielded highly proliferative and clonogenic CCs with an average population doubling time of 17.2 ± 0.2, of which 80% were at the G1 phase. We identified two distinctly different CC populations based on its Sox2 expression, which was found to inversely related to their nkx2.5 and gata4 expression. To study CCs after MSC coculture, we developed micron-sized particles of iron oxide-based magnetic reisolation method to separate CCs from MSCs for subsequent analysis. Through validation using the sex and species mismatch CC-MSC coculture method, we confirmed that the purity of the reisolated cells was greater than 85%. In coculture experiment, we found that MSCs prominently enhanced Ctni and Mef2c expressions in Sox2 pos CCs after the induction of cardiac differentiation, and the level was higher than that of conditioned medium Sox2 pos CCs. However, these effects were not found in Sox2 neg CCs. Immunofluorescence labeling confirmed the presence of cardiac-like cells within Sox2 pos CCs after differentiation, identified by its cardiac troponin I and α-sarcomeric actinin expressions. In conclusion, this study shows that MSCs enhance CC differentiation toward cardiac myocytes. This enhancement is dependent on CC stemness state, which is determined by Sox2 expression.
  12. Fulltext Extracellular matrix from decellularized mesenchymal stem cells improves cardiac gene expressions and oxidative resistance in cardiac C-kit cells
    Ng WH, Ramasamy R, Yong YK, Ngalim SH, Lim V, Shaharuddin B, et al.
    Regen Ther, 2019 Dec;11:8-16.
    PMID: 31193142 DOI: 10.1016/j.reth.2019.03.006
    OBJECTIVE: Myocardial infarction remains the number one killer disease worldwide. Cellular therapy using cardiac c-kit cells (CCs) are capable of regenerating injured heart. Previous studies showed mesenchymal stem cell-derived (MSC) extracellular matrices can provide structural support and are capable of regulating stem cell functions and differentiation. This study aimed to evaluate the effects of human MSC-derived matrices for CC growth and differentiation.

    METHODS: Human Wharton's Jelly-derived MSCs were cultured in ascorbic acid supplemented medium for 14 days prior to decellularisation using two methods. 1% SDS/Triton X-100 (ST) or 20 mM ammonia/Triton X-100 (AT). CCs isolated from 4-week-old C57/BL6N mice were cultured on the decellularised MSC matrices, and induced to differentiate into cardiomyocytes in cardiogenic medium for 21 days. Cardiac differentiation was assessed by immunocytochemistry and qPCR. All data were analysed using ANOVA.

    RESULTS: In vitro decellularisation using ST method caused matrix delamination from the wells. In contrast, decellularisation using AT improved the matrix retention up to 30% (p 

  13. Fulltext Production of Lentivirus carrying green fluorescent protein with different promoters for in vitro gene transfer
    Siew, Ching Ngai, Ramasamy, Rajesh, Syahril Abdullah
    Pertanika Journal of Science & Technology, 2012;20(2):269-281.
    MyJurnal
    Many diseases are potential targets for gene therapy using either non-viral or viral vectors. Unlike nonviralmethods, viral vectors, such as lentiviruses, have the ability to integrate into the host chromosome,which can lead to long-term transgene expression. Lentiviruses have advantages over other types ofviruses due to their capacity to transduce non-dividing cells. An optimized generation of lentivirusescarrying green fluorescent protein (GFP) reporter gene driven by either UbC (LV/UbC/GFP) orCMV (LV/CMV/GFP) promoter is described in this paper. The lentiviruses were produced by cotransfectinglentiviral expression constructs and packaging mix into 293FT lentivirus producer cell lines.Lipofectamine was highly efficient in transfecting the cells compared to Transfast and Polyethyleneimine(PEI). Following cell transfection, syncytia were clearly visible at day 2. Lentiviruses were harvestedat days 1, 2 and 3 post-transfection. The highest transduction efficiency was read from LV/CMV/GFPharvested at day 2 post-transfection and LV/UbC/GFP harvested at day 3 post-transfection. Finally,the GFP expression in COS-7 cells was determined at day 2 and day 14 post-transduction for transientand stable GFP expression. It was found that the GFP expression declined overtime. However, thetransduction efficiency and duration of the transgene expression in COS-7 cells transduced with LV/CMV/GFP were higher compared to LV/UbC/GFP. In conclusion, we have successfully produced lentivirusescarrying GFP with different promoters and shown that the viruses were able to infect COS-7 cells atdifferent efficiencies. Meanwhile, the generation of the active lentiviruses will allow us to proceed to the subsequent analysis of the effect of regulatory elements in future study.
  14. Call for TERMIS-AP 2020 Special Issue Papers: Revolutionizing Regenerative Research Strategies Towards Precision Medicine
    Ramasamy R, Yahaya BH, Sik Loo T
    Tissue Eng Part A, 2020 Aug;26(15-16):835-836.
    PMID: 32762624 DOI: 10.1089/ten.tea.2020.29020.cfp
  15. Effects of macrophage colony-stimulating factor on microglial responses to lipopolysaccharide and beta amyloid
    Vidyadaran S, Ooi YY, Subramaiam H, Badiei A, Abdullah M, Ramasamy R, et al.
    Cell Immunol, 2009;259(1):105-10.
    PMID: 19577228 DOI: 10.1016/j.cellimm.2009.06.005
    A challenge for studies involving microglia cultures is obtaining sufficient cells for downstream experiments. Macrophage colony-stimulating factor (M-CSF) has been used to improve yield of microglia in culture. However, the effects of M-CSF on activation profiles of microglia cultures are still unclear. Microglia activation is characterised by upregulation of co-stimulatory molecules and an inflammatory phenotype. The aim of this study is to demonstrate whether M-CSF supplementation alters microglial responses in resting and activated conditions. Microglia derived from mixed glia cultures and the BV-2 microglia cell line were cultivated with/without M-CSF and activated with lipopolysaccharide (LPS) and beta amyloid (Abeta). We show M-CSF expands primary microglia without affecting microglial responses to LPS and Abeta, as shown by the comparable expression of MHC class II and CD40 to microglia grown without this growth factor. M-CSF supplementation in BV-2 cells had no effect on nitric oxide (NO) production. Therefore, M-CSF can be considered for improving microglia yield in culture without introducing activation artefacts.
  16. 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.
  17. Fulltext Qualitative flow cytometric analysis of Malaysian myelodysplastic syndromes (MDS) patients
    Mohadese Hashem B, Ramasamy R, Sabariah MN, Seman Z
    Med J Malaysia, 2012 Feb;67(1):77-80.
    PMID: 22582553 MyJurnal
    Myelodysplastic syndromes (MDS) are a group of haematological malignancies categorized by ineffective hematopoiesis that result in dysplasia. Although morphological diagnosis is a traditional and standard technique that is used for the diagnosis of MDS, the heterogeneous blood and bone marrow characteristics of MDS patients can potentially obscure the right diagnosis. Thus, we have utilized flow cytometric immunophenotyping as a supportive mechanism to obtain a more accurate and faster method for detection of abnormal markers in MDS. Flow cytometry was used for analyzing bone marrow samples from newly diagnosed MDS patients to investigate the abnormal antigen expression patterns in granulocytic, monocytic, erythroid, lymphoid lineages and myeloid precursors. The results were compared with those obtained from cases that had Idiopathic Thrombocytopenic Purpura (ITP) as a control. The most common abnormality found in the granulocytic lineage was the decrease of CD10. Low expressions of CD13 were the most frequent abnormality in the monocytic lineage. The erythroid lineage was found to have low expression of CD235A+/CD71+, reduce of CD71 and decreased CD235a. In conclusion, this method is useful for confirming cases in which it is difficult to make a diagnosis by morphology.
  18. 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.
  19. 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.
  20. Evaluation of metabolic and immunological changes in streptozotocin-nicotinamide induced diabetic rats
    Mojani MS, Sarmadi VH, Vellasamy S, Sandrasaigaran P, Rahmat A, Peng LS, et al.
    Cell Immunol, 2014 May-Jun;289(1-2):145-9.
    PMID: 24791700 DOI: 10.1016/j.cellimm.2014.04.004
    Type 2 diabetes is a chronic disease with growing public health concern globally. Finding remedies to assist this health issue requires recruiting appropriate animal model for experimental studies. This study was designated to evaluate metabolic and immunologic changes in streptozotocin-nicotinamide induced diabetic rats as a model of type 2 diabetes. Male rats were induced diabetes using nicotinamide (110 mg/kg) and streptozotocin (65 mg/kg). Following 42 days, biochemical and immunological tests showed that diabetic rats had higher levels of blood glucose, WBC, certain abnormalities in lipid profile and insufficient mitogenic responses of lymphocytes (p<0.05). However, the status of the total antioxidant, inflammatory biomarkers and other parameters of full blood count (except HCT) were not significantly altered. Phenotyping assay indicated insignificant lymphocyte subtype imbalances excluding a significant rise in the level of CD4+CD25+ marker (p<0.05). This model of diabetic animals may represent some but not all symptoms of human type 2 diabetes.
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