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Displaying publications 21 - 31 of 31 in total

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Discovery of HLA-B*35:368, a novel HLA-B*35 variant, in a Singaporean Malay hematopoietic stem cell donor

Kaur A, Cho L, Cereb N, Lin PY, Yang KL

HLA, 2020 07;96(1):94-95.
PMID: 32166893 DOI: 10.1111/tan.13862

DNA substitutions from codons 69 to 71 of HLA-B*35:05:01:01 result in a novel allele, HLA-B*35:368.

Matched MeSH terms: Hematopoietic Stem Cells
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.

Matched MeSH terms: Hematopoietic Stem Cells
Fulltext Feasibility and toxicity of hematopoietic stem cell transplant in multiple sclerosis

Kuan TLT, Amini F, Seghayat MS

Iran J Basic Med Sci, 2017 Jul;20(7):729-738.
PMID: 28852436 DOI: 10.22038/IJBMS.2017.9000

Multiple sclerosis is a debilitating disease of the central nervous system. It affects people of all ages but is more prevalent among 20-40 year olds. Patients with MS can be presented with potentially any neurological symptom depending on the location of the lesion. A quarter of patients with MS suffer from bilateral lower limb spasticity among other symptoms. These devastating effects can be detrimental to the patient's quality of life. Hematopoietic stem cells (HSCs) have been used as a treatment for MS over the past 2 decades but their safety and efficacy has are undetermined. The objective of this study is to evaluate the feasibility and toxicity of autologous HSCs transplantation in MS. A literature search was done from 1997 to 2016 using different keywords. A total of 9 articles, which met the inclusion and exclusion criteria, were included in this review. The type of conditioning regimen and technique of stem cell mobilization are summarized and compared in this study. All studies reported high-dose immunosuppressive therapy with autologous HSCs transplantation being an effective treatment option for severe cases of multiple sclerosis. Fever, sepsis, and immunosuppression side effects were the most observed adverse effects that were reported in the selected studies. HSCs is a feasible treatment for patients with MS; nevertheless the safety is still a concern due to chemo toxicity.

Matched MeSH terms: Hematopoietic Stem Cells
Fulltext Analysis of self-renewing and differentiation-related microRNAs and transcription factors in multilineage mouse hematopoietic stem/progenitor cells induced by 1,4-benzoquinone

Dewi R, Yusoff NA, Abdul Razak SR, Abd Hamid Z

PeerJ, 2023;11:e15608.
PMID: 37456886 DOI: 10.7717/peerj.15608

BACKGROUND: HSPCs are targets for benzene-induced hematotoxicity and leukemogenesis. However, benzene toxicity targeting microRNAs (miRNAs) and transcription factors (TF) that are involve in regulating self-renewing and differentiation of HSPCs comprising of different hematopoietic lineages remains poorly understood. In this study, the effect of a benzene metabolite, 1,4-benzoquinone (1,4-BQ) exposure, in HSPCs focusing on the self-renewing (miRNAs: miR-196b and miR-29a; TF: HoxB4, Bmi-1) and differentiation (miRNAs: miR-181a, TF: GATA3) pathways were investigated.
METHODS: Freshly isolated mouse BM cells were initially exposed to 1,4-BQ at 1.25 to 5 µM for 24 h, followed by miRNAs and TF studies in BM cells. Then, the miRNAs expression was further evaluated in HSPCs of different lineages comprised of myeloid, erythroid and pre-B lymphoid progenitors following 7-14 days of colony forming unit (CFU) assay.
RESULTS: Exposure to 1,4-BQ in BM cells significantly (p

Matched MeSH terms: Hematopoietic Stem Cells
In vitro expression of erythropoietin by transfected human mesenchymal stromal cells

Mok PL, Cheong SK, Leong CF, Othman A

Cytotherapy, 2008;10(2):116-24.
PMID: 18368590 DOI: 10.1080/14653240701816996

Mesenchymal stromal cells (MSC) are pluripotent progenitor cells that can be found in human bone marrow (BM). These cells have low immunogenicity and could suppress alloreactive T-cell responses. In the current study, MSC were tested for their capacity to carry and deliver the erythropoietin (EPO) gene in vitro.

Matched MeSH terms: Hematopoietic Stem Cells/cytology
Fulltext Preeclampsia in pregnancy affecting the stemness and differentiation potency of haematopoietic stem cell of the umbilical cord blood

Nordin F, Idris MRM, Mahdy ZA, Wahid SFA

BMC Pregnancy Childbirth, 2020 Jul 10;20(1):399.
PMID: 32650736 DOI: 10.1186/s12884-020-03084-7

BACKGROUND: Umbilical cord blood (UCB) has been proposed as the potential source of haematopoietic stem cells (HSC) for allogeneic transplantation. However, few studies have shown that a common disease in pregnancy such as preeclampsia would affect the quality of UCB-HSC. Total nucleated cell count (TNC) is an important parameter that can be used to predict engraftment including UCB banking. Colony forming unit (CFU) assay is widely used as an indicator to predict the success of engraftment, since direct quantitative assay for HSC proliferation is unavailable. The aim of this study is to investigate the effects of preeclampsia in pregnancy on the stemness and differentiation potency of UCB-HSC.
METHODS: Mononuclear cells (MNC) were isolated from UCB and further enriched for CD34+ cells using immune-magnetic method followed by CFU assay. A panel of HSC markers including differentiated haematopoietic markers were used to confirm the differentiation ability of UCB-HSC by flow cytometry analysis.
RESULTS/ DISCUSSION: The HSC progenitor's colonies from the preeclampsia group were significantly lower compared to the control. This correlates with the low UCB volume, TNC and CD34+ cells count. In addition, the UCB-enriched CD34+ population were lymphoid progenitors and capable to differentiate into natural killer cells and T-lymphocytes.
CONCLUSION: These findings should be taken into consideration when selecting UCB from preeclamptic mothers for banking and predicting successful treatment related to UCB transplant.

Matched MeSH terms: Hematopoietic Stem Cells/cytology*
Isolation of purified autologous peripheral blood CD34+ cells with low T cell content using CliniMACS device--a local experience

Leong CF, Habsah A, Teh HS, Goh KY, Fadilah SA, Cheong SK

Malays J Pathol, 2008 Jun;30(1):31-6.
PMID: 19108409

Peripheral blood stem cells (PBSC) mobilised with growth factor with or without chemotherapeutic regimens, are used increasingly in both autologous and allogeneic transplantation. Previously, many PBSC harvests are used directly without ex vivo manipulation, and these PBSC have been shown to be contaminated with tumour cells, which may contribute to subsequent relapses post transplantation. Therefore, requirement for purging of malignant cells from the harvest has initiated the use of various methods to reduce tumour cell contamination of the graft by the positive selection of CD34+ progenitor cells or negative selection of tumour cells using other cell-specific antigens. We report here our local experience with the CliniMACS (magnetic-activated cell separation system) in eight adult patients with haematologic malignancies.

Matched MeSH terms: Hematopoietic Stem Cells/cytology*
Adult stem cells: a clinical update

Totey S, Totey S, Pal R, Pal R

J Stem Cells, 2009;4(2):105-21.
PMID: 20232596

There has been unprecedented interest in stem cell research mainly because of their true potential and hope that they offer to the patients as a cell therapy with the prospect to treat hitherto incurable diseases. Despite the worldwide interest and efforts that have been put in this research, major fundamental issues are still unresolved. Adult stem cells such as hematopoietic stem cells (HSC) and mesenchymal stem cells (MSC) are already under clinical applications and there are several examples of plasticity and self-renewal where adult stem cells or their precursor cells can be re-programmed by extra cellular cues or internal cues to alter their character in a way that could have important application for cell therapy and regenerative medicine. From a clinical perspective, no other area of stem cell biology has been applied as successfully as has transplantation of bone marrow stem cells and cord blood stem cells for the treatment of hematological diseases. In the last few years, research in stem cell biology has expanded staggeringly, engendering new perspectives concerning the identity, origin, and full therapeutic potential of tissue-specific stem cells. This review will focus on the use of adult stem cells, its biology in the context of cell plasticity and their therapeutic potential for repair of different tissues and organs.

Matched MeSH terms: Hematopoietic Stem Cells/physiology
Fulltext DNA methylation and histone modifications are the molecular lock in lentivirally transduced hematopoietic progenitor cells

Ngai SC, Rosli R, Al Abbar A, Abdullah S

Biomed Res Int, 2015;2015:346134.
PMID: 25961011 DOI: 10.1155/2015/346134

Stable introduction of a functional gene in hematopoietic progenitor cells (HPCs) has appeared to be an alternative approach to correct genetically linked blood diseases. However, it is still unclear whether lentiviral vector (LV) is subjected to gene silencing in HPCs. Here, we show that LV carrying green fluorescent protein (GFP) reporter gene driven by cytomegalovirus (CMV) promoter was subjected to transgene silencing after transduction into HPCs. This phenomenon was not due to the deletion of proviral copy number. Study using DNA demethylating agent and histone deacetylase (HDAC) inhibitor showed that the drugs could either prevent or reverse the silencing effect. Using sodium bisulfite sequencing and chromatin immunoprecipitation (ChIP) assay, we demonstrated that DNA methylation occurred soon after LV transduction. At the highest level of gene expression, CMV promoter was acetylated and was in a euchromatin state, while GFP reporter gene was acetylated but was strangely in a heterochromatin state. When the expression declined, CMV promoter underwent transition from acetylated and euchromatic state to a heterochromatic state, while the GFP reporter gene was in deacetylated and heterochromatic state. With these, we verify that DNA methylation and dynamic histone modifications lead to transgene silencing in HPCs transduced with LV.

Matched MeSH terms: Hematopoietic Stem Cells*
Fulltext Trisomy X and myelodysplastic syndrome (MDS) with eosinophilia

Eusni, R.M.T., Leong, C.F., Salwa, S.

Malaysian Journal of Medicine and Health Sciences, 2012;8(2):65-67.
MyJurnal

We reported a young patient with myelodysplastic syndrome (MDS) with eosinophilia, in which her chromosomal analysis revealed the presence of trisomy X and a marker chromosome at chromosome 11. The technique used to detect the chromosomal abnormalities is a multicoloured –fluorescent in situ hybridization technique (M-FISH). Our observation suggested that these underlying chromosomal abnormalities were probably responsible for her development of MDS with eosinophilia.
Myelodysplastic syndrome (MDS) is a condition whereby there is ineffective production of haematopoietic stem cells and poor quality of cells produced. The cause can either be a primary bone marrow problem, de novo or therapy related. Most MDS cases are secondary rather than primary. Many chromosomal abnormalities have been found in cases of myelodysplastic syndrome. We described a case of MDS with eosinophilia in association with presence of trisomy X and a marker chromosome in chromosome 11.

Matched MeSH terms: Hematopoietic Stem Cells
Fulltext The effect of human mesenchymal stem cell on neutrophil oxidative burst

Ramasamy, R., Krishna, K., Maqbool, M., Vellasamy, S., Sarmadi, V. H., Abdullah, M., et al.

Malaysian Journal of Medicine and Health Sciences, 2010;6(2):11-17.
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.

Matched MeSH terms: Hematopoietic Stem Cells