Displaying publications 21 - 40 of 74 in total

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  1. Ridzuan N, Al Abbar A, Yip WK, Maqbool M, Ramasamy R
    Stem Cells Int, 2016;2016:8487264.
    PMID: 27579045 DOI: 10.1155/2016/8487264
    The present study is aimed at optimizing the in vitro culture protocol for generation of rat bone marrow- (BM-) derived mesenchymal stem cells (MSCs) and characterizing the culture-mediated cellular senescence. The initial phase of generation and characterization was conducted using the adherent cells from Sprague Dawley (SD) rat's BM via morphological analysis, growth kinetics, colony forming unit capacity, immunophenotyping, and mesodermal lineage differentiation. Mesenchymal stem cells were successfully generated and characterized as delineated by the expressions of CD90.1, CD44H, CD29, and CD71 and lack of CD11b/c and CD45 markers. Upon induction, rBM-MSCs differentiated into osteocytes and adipocytes and expressed osteocytes and adipocytes genes. However, a decline in cell growth was observed at passage 4 onwards and it was further deciphered through apoptosis, cell cycle, and senescence assays. Despite the enhanced cell viability at later passages (P4-5), the expression of senescence marker, β-galactosidase, was significantly increased at passage 5. Furthermore, the cell cycle analysis has confirmed the in vitro culture-mediated cellular senescence where cells were arrested at the G0/G1 phase of cell cycle. Although the currently optimized protocols had successfully yielded rBM-MSCs, the culture-mediated cellular senescence limits the growth of rBM-MSCs and its potential use in rat-based MSC research.
    Matched MeSH terms: Immunophenotyping
  2. Sandrasaigaran P, Algraittee SJR, Ahmad AR, Vidyadaran S, Ramasamy R
    Cytotechnology, 2018 Jun;70(3):1037-1050.
    PMID: 29497876 DOI: 10.1007/s10616-017-0182-4
    Mesenchymal stem cells (MSCs) exert potent immuno-regulatory activities on various immune cells and also differentiate into various mesodermal lineages besides retaining a distinct self-renewal ability. Such exclusive characteristics had enabled MSCs to be recognised as an ideal source for cell-based treatment in regenerative medicine and immunotherapy. Thus, considering MSCs for treating degenerative disease of organs with limited regenerative potential such as cartilage would serve as an ideal therapy. This study explored the feasibility of generating human cartilage-derived MSCs (hC-MSCs) from sports injured patients and characterised based on multipotent differentiation and immunosuppressive activities. Cartilage tissues harvested from a non-weight bearing region during an arthroscopy procedure were used to generate MSCs. Despite the classic morphology of fibroblast-like cells and a defined immunophenotyping, MSCs expressed early embryonic transcriptional markers (SOX2, REX1, OCT4 and NANOG) and differentiated into chondrocytes, adipocytes and osteocytes when induced accordingly. Upon co-culture with PHA-L activated T-cells, hC-MSCs suppressed the proliferation of the T-cells in a dose-dependent manner. Although, hC-MSCs did not alter the activation profile of T cells significantly, yet prevented the entering of activated T cells into S phase of the cell cycle by cell cycle arrest. The present study has strengthened the evidence of tissue-resident mesenchymal stem cells in human cartilage tissue. The endogenous MSCs could be an excellent tool in treating dysregulated immune response that associated with cartilage since hC-MSCs exerted both immunosuppressive and regenerative capabilities.
    Matched MeSH terms: Immunophenotyping
  3. Chow PW, Abdul Hamid Z, Chan KM, Inayat-Hussain SH, Rajab NF
    Toxicol Appl Pharmacol, 2015 Apr 1;284(1):8-15.
    PMID: 25645895 DOI: 10.1016/j.taap.2015.01.016
    Hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) are sensitive targets for benzene-induced hematotoxicity and leukemogenesis. The impact of benzene exposure on the complex microenvironment of HSCs and HPCs remains elusive. This study aims to investigate the mechanism linking benzene exposure to targeting HSCs and HPCs using phenotypic and clonogenic analyses. Mouse bone marrow (BM) cells were exposed ex vivo to the benzene metabolite, 1,4-benzoquinone (1,4-BQ), for 24h. Expression of cellular surface antigens for HSC (Sca-1), myeloid (Gr-1, CD11b), and lymphoid (CD45, CD3e) populations were confirmed by flow cytometry. The clonogenicity of cells was studied using the colony-forming unit (CFU) assay for multilineage (CFU-GM and CFU-GEMM) and single-lineage (CFU-E, BFU-E, CFU-G, and CFU-M) progenitors. 1,4-BQ demonstrated concentration-dependent cytotoxicity in mouse BM cells. The percentage of apoptotic cells increased (p < 0.05) following 1,4-BQ exposure. Exposure to 1,4-BQ showed no significant effect on CD3e(+) cells but reduced the total counts of Sca-1(+), CD11b(+), Gr-1(+), and CD45(+) cells at 7 and 12 μM (p < 0.05). Furthermore, the CFU assay showed reduced (p < 0.05) clonogenicity in 1,4-BQ-treated cells. 1,4-BQ induced CFU-dependent cytotoxicity by significantly inhibiting colony growth for CFU-E, BFU-E, CFU-G, and CFU-M starting at a low concentration of exposure (5μM); whereas for the CFU-GM and CFU-GEMM, the inhibition of colony growth was remarkable only at 7 and 12μM of 1,4-BQ, respectively. Taken together, 1,4-BQ caused lineage-related cytotoxicity in mouse HPCs, demonstrating greater toxicity in single-lineage progenitors than in those of multi-lineage.
    Matched MeSH terms: Immunophenotyping
  4. Gill HK, Keoh TS, Dhaliwal JS, Moore S, Kim TS, Hassan R, et al.
    Cancer Genet. Cytogenet., 2005 Jan 15;156(2):129-33.
    PMID: 15642392
    Eighty-eight multi-ethnic Malaysian pediatric acute lymphoblastic leukemia (ALL) patients were screened for the TEL-AML1 rearrangement by reverse transcription-polymerase chain reaction (RT-PCR). Fluorescence in situ hybridization (FISH) was used as an independent screen for 30 cases and to confirm RT-PCR positive cases. Seventeen patients, or 19%, were found to be t(12;21) positive. Ethnically the group comprised 12 Malays, 4 Chinese, and 1 Indian. All patients, including 1 with an unusual blast cell morphology who suffered an early relapse and death, were characteristic TEL-AML1 cases in cell count, age, ALL subset classification, and fusion transcript expressed. This study shows that in Malaysia, TEL-AML1 is found in the same distinct ALL subset and at a similar frequency as in other diverse childhood ALL cohorts.
    Matched MeSH terms: Immunophenotyping
  5. Kim LH, Peh SC, Poppema S
    Int J Cancer, 2003 Nov 1;107(2):250-5.
    PMID: 12949802
    Isolation of single cells permits analysis of DNA or RNA from individual cells among heterogeneous populations. This technique is particularly useful in the study of classical Hodgkin's lymphoma (cHL) due to the scarcity of H/RS tumor cells among large numbers of reactive leukocytes. In a previous study, we found a high frequency of dual LMP-1 variant (concurrent presence of deleted and nondeleted variants) in cHL from whole-tissue sections. For the present study, we applied a single-cell isolation technique to determine the LMP-1 oncogene variant in EBV-associated H/RS cells. Five cases of EBV-infected cHL, containing nondeleted (n=1), deleted (n=1) and dual infection (n=3) based on whole-tissue section analysis, were selected for study. Paraffin-embedded tissue sections were stained with antibody to LMP-1 and positively stained H/RS cells isolated using a semiautomated micromanipulator. Each isolated single cell was subjected to PCR for amplification of the LMP-1 gene flanking the 30 bp deletion region and Xho1 restriction site. Cases with either nondeleted variant or the deleted variant showed similar LMP-1 variant expression in isolated single H/RS cells. However, 1 of the 3 cases with dual variants showed only the deleted variant in H/RS cells. The other 2 cases showed mixed patterns of deleted, nondeleted and dual LMP-1 variants in isolated single H/RS cells. All cases showed loss of the Xho1 restriction site, with the exception of the case with nondeleted LMP-1. Results of single-H/RS cell analysis of the Xho1 restriction site concur with those of whole-tissue section amplification. A mixed pattern of LMP-1 variants was observed in isolated H/RS cells, and it is speculated that this is due to the accumulation of mutation and deletion events.
    Matched MeSH terms: Immunophenotyping
  6. Kim LH, Nadarajah VS, Peh SC, Poppema S
    Histopathology, 2004 Mar;44(3):257-67.
    PMID: 14987230 DOI: 10.1111/j.0309-0167.2004.01829.x
    AIMS: To examine the expression of the Bcl-2 family of proteins (Bcl-2, Bcl-x, Bcl-xL and Bax) in classical Hodgkin's lymphoma (cHL) and to correlate the expression of these proteins with proliferation, apoptosis and the presence of Epstein-Barr virus (EBV).

    METHODS AND RESULTS: Expression of the Bcl-2 family of proteins was detected by immunohistochemistry, proliferation was determined by Ki67 labelling and apoptosis by TUNEL in-situ hybridization. EBV was detected by Epstein-Barr virus early RNA (EBER) in-situ hybridization. Expression of Bcl-2, Bcl-x, Bcl-xL and Bax was detected in the Hodgkin/Reed-Sternberg (H/RS) cells in 43.7% (27/62), 87.5% (56/64), 67.2% (41/61) and 74.6% (47/63) of the cHL cases, respectively. EBER was detected in 53% (35/66) of the cases, whereas Ki67 was observed in 86.7% (52/60) of the cases. Apoptotic H/RS cells were observed infrequently, and only 43.2% (11/26) of the cases showed an apoptotic index of > or = 10% in the H/RS cells. A statistically significant inverse relationship was observed between the expression of Bcl-2 and the presence of EBV (P = 0.003). Bcl-xL showed an inverse correlation with apoptosis in the H/RS cells (P = 0.004).

    CONCLUSIONS: The higher Bcl-xL expression (67.2%) compared with Bcl-2 expression (43.5%) observed in cHL as well as the statistically significant inverse relationship between Bcl-xL and apoptosis suggests that Bcl-xL plays an important role in the survival of H/RS cells. Expression of Bax may be neutralized by other anti-apoptotic members of the family such as Bcl-2 and/or Bcl-xL.
    Matched MeSH terms: Immunophenotyping
  7. Tai YC, Tan JA, Peh SC
    Virchows Arch., 2004 Nov;445(5):506-14.
    PMID: 15365830
    t(11;18)(q21;q21) Translocation and trisomy 3 are the most common chromosomal aberrations reported in low-grade mucosa-associated lymphoid tissue (MALT) lymphoma. The current study aims to investigate the frequency of these chromosomal aberrations in a series of 52 extranodal B-cell lymphomas. The tumours were categorised into three histological grades: grade 1 (low-grade lymphoma of MALT type), grade 2 [diffuse large B-cell lymphoma (DLBCL) with MALT component] and grade 3 (DLBCL without MALT component). Fluorescence in situ hybridisation analyses on paraffin tissue sections were performed using a locus-specific probe for the 18q21 region and a centromeric probe for chromosome 3. The 18q21 rearrangement was detected in 9 of 40 (23%) cases, including 7 of 23 (30%) grade-1 and 2 of 11 (18%) grade-3 tumours. Amplification of the 18q21 region was detected in 10 of 40 (25%) cases, and trisomy 3 was detected in 9 of 34 (26%) cases. Amplification of the 18q21 region may be an important alternative pathogenetic pathway in MALT lymphoma and was found almost exclusively in tumours without 18q21 rearrangement. Our study showed that tumours with 18q21 rearrangement and 18q21 amplification develop along two distinct pathways, and the latter was more likely to transform into high-grade tumours upon acquisition of additional genetic alterations, such as trisomy 3. Trisomy 3 was more frequently found in coexistence with 18q21 abnormalities, suggesting that it was more likely to be a secondary aberration.
    Matched MeSH terms: Immunophenotyping
  8. Tai YC, Kim LH, Peh SC
    Pathol. Int., 2004 Mar;54(3):158-66.
    PMID: 14989738
    Natural killer (NK)/T-cell lymphomas are frequently associated with Epstein-Barr virus (EBV), and usually lack TCR gene rearrangement. Studies from Asia have reported frequent deletion in the LMP-1 gene in EBV-associated nasopharyngeal carcinoma (NPC). The present study aims to investigate LMP-1 and TCRgamma gene status in upper aerodigestive tract lymphomas. A total of 43 cases were classified into T-, B-, and NK/T-cell tumors based on the phenotype expressions of CD3(+)/CD20(-)/CD56(-), CD3(-)/CD20(+)/CD56(-), and CD3(+)/CD20(-)/CD56(+), respectively. The presence of EBV in the tumor was confirmed by EBV early RNA-in situ hybridization. LMP-1 gene deletion and TCR gamma gene rearrangement were analyzed by polymerase chain reaction on paraffin-embedded tissues. There were 20 NK/T-, eight T-, and 15 B-cell phenotype lymphomas in the present series, and EBV was detected in 19 (95%), two (25%), and three (20%) cases in the respective groups. All EBV+ cases carried 30-bp deletion in the LMP-1 gene, and two of the NK/T-cell cases were infected by both the wild type and deleted strains. Five (25%) of the NK/T-cell phenotype lymphomas showed rearranged TCR gamma gene. The present study revealed a high frequency of EBV association, and a high frequency of 30-bp deletion in the LMP-1 gene in the virus in the present series of lymphoma. The NK/T-phenotype lymphomas are comprised of both NK-cell and cytotoxic T-lymphocyte-derived tumors.
    Matched MeSH terms: Immunophenotyping
  9. Wong KK, Prepageran N, Peh SC
    Pathology, 2009 Feb;41(2):133-9.
    PMID: 18972319 DOI: 10.1080/00313020802436790
    AIMS: To stratify upper aerodigestive tract (UAT) diffuse large B-cell lymphoma (DLBCL) into prognostic subgroups by immunohistochemical staining (IHC) method, and to evaluate the association rate of UAT DLBCL with Epstein-Barr virus (EBV).

    METHODS: Using a panel of antibodies to CD10, Bcl-6, MUM1 and CD138, consecutive cases of primary UAT DLBCL were stratified into subgroups of germinal centre B-cell-like (GCB) and non-GCB, phenotype profile patterns A, B and C, as proposed by Hans et al. and Chang et al., respectively. EBER in situ hybridisation technique was applied for the detection of EBV in the tumours.

    RESULTS: In this series of 32 cases of UAT DLBCL, 34% (11/32) were GCB, and 66% (21/32) were non-GCB types; 59% (19/32) had combined patterns A and B, and 41% (13/32) had pattern C. Statistical analysis revealed no significant difference in the occurrence of these prognostic subgroups in the UAT when compared with series of de novo DLBCL from all sites. There was also no site difference in phenotype protein expressions, with the exception of MUM1. EBER in situ hybridisation stain demonstrated only one EBV infected case.

    CONCLUSIONS: Prognostic subgroup distribution of UAT DLBCL is similar to de novo DLBCL from all sites, and EBV association is very infrequent.

    Matched MeSH terms: Immunophenotyping
  10. Tai YC, Kim LH, Peh SC
    Pathology, 2003 Oct;35(5):436-43.
    PMID: 14555389
    AIMS: The most common recurrent genetic aberration in anaplastic large cell lymphoma (ALCL) is translocation involving the ALK gene that results in ectopic expression of ALK protein in lymphoid tissue. This study aims to investigate the frequency of ALK gene rearrangement in a series of Asian ALCL.

    METHODS: ALK gene rearrangement was detected by immunostaining of ALK protein and fluorescence in situ hybridisation (FISH) targeting at the 2p23 region.

    RESULTS: The expression of ALK protein was detected in 24/34 (71%) of the cases, and it was significantly higher in childhood cases (100%) when compared to adult cases (47%). The analyses by FISH were consistent with the results from immunostaining of ALK protein, but the analyses were only successful in 15/34 (44%) cases. FISH analyses detected extra copies of ALK gene in three cases, including one case that expressed ALK protein and showed 2p23 rearrangement.

    CONCLUSIONS: The current series revealed a high frequency of ALK gene rearrangement, especially in the children. Immunostaining of ALK protein is a reliable indication of ALK gene rearrangement, and is superior to FISH. However, FISH analysis is useful in detecting other genetic aberrations that are not related to ALK gene rearrangement.

    Matched MeSH terms: Immunophenotyping
  11. Shia AK, Gan GG, Jairaman S, Peh SC
    J Clin Pathol, 2005 Sep;58(9):962-7.
    PMID: 16126878
    Recent reports have divided diffuse large B cell lymphoma (DLBCL) into germinal centre B cell-like and activated B cell-like subgroups with implicated differences in prognosis.
    Matched MeSH terms: Immunophenotyping
  12. Bere A, Tayib S, Kriek JM, Masson L, Jaumdally SZ, Barnabas SL, et al.
    Clin Immunol, 2014 Feb;150(2):210-9.
    PMID: 24440646 DOI: 10.1016/j.clim.2013.12.005
    HIV-infected individuals experience more persistent HPV infections and are less likely to resolve genital warts. This study compared phenotype and functions of NK and T cells from genital warts and blood from 67 women. We compared in vitro functional responses of NK and T cells by multiparametric flow cytometry. HIV+ women had significantly lower frequencies of CD4 T cells in warts (p = 0.001) and blood (p = 0.001). While the distribution of NK cell subsets was similar, HIV+ women tended to have lower frequencies of CD56(Dim) NK cells in both blood (p = 0.0001) and warts (p = 0.006) than HIV- women. Wart NK cells from HIV+ women expressed significantly lower CD107a and produced IFN-γ. HAART status was not associated with differences in NK cell functionality. We conclude that wart NK cells from HIV+ women have defects in their ability to degranulate and/or secrete IFN-γ, which may provide insights into why HIV+ women fail to spontaneously resolve genital warts.
    Matched MeSH terms: Immunophenotyping
  13. Leong CF, Raudhawati O, Cheong SK, Sivagengei K, Noor Hamidah H
    Pathology, 2003 Oct;35(5):422-7.
    PMID: 14555387
    AIMS: Epithelial membrane antigen (EMA) or MUC1 belongs to a heterogeneous group of heavily glycosylated proteins and is expressed in most normal and epithelial neoplastic cells. EMA is also expressed in plasma cells, anaplastic large cell lymphoma (Ki-1 antigen), malignant histiocytosis and erythroleukaemia. In 1996, Cheong et al. (Hematology 1996; 1: 223) demonstrated the positive expression of EMA in monoblasts. Since there were very few useful markers for differentiating subtypes of acute myeloid leukaemia with a monocytic component from the those without, a study was conducted to evaluate the prevalence of EMA expression and its relationship with known markers for monocytic-macrophage lineage (CD11c, CD14 and intracellular CD68) in monocytes and monoblasts.

    METHODS: EMA detection was performed by flow cytometry in monocytes and monoblasts. EMA expression was compared with other known markers of monocytic-macrophage lineage (CD11c, CD14 and intracellular CD68). Samples of purified monocytes were obtained from 20 healthy volunteers. Twenty-two cases of monocytic AML (M4 and M5) were studied and controls were selected from 20 cases of acute lymphoblastic leukaemia (ALL) and 18 cases of non-monocytic AML (M0, M1, M2, M3, and M7).

    RESULTS: EMA was shown to be expressed strongly on the surface of all purified monocytes. EMA expression was observed on blast cells in 18/22 (81.8%) cases of AML M4 and M5, but not in that of non-monocytic AML or ALL. In this study EMA monoclonal antibody has demonstrated a strong association (P<0.001) with all the other known markers of monocytic-macrophage lineage in acute leukaemia subtypes. EMA had also shown 100% specificity and 81.8% sensitivity in the diagnosis of AML M4 and M5.

    CONCLUSIONS: The monoclonal antibody EMA (clone E29) is a useful marker in the classification of acute myeloid leukaemia and can be used as a supplementary analysis for the diagnosis of acute leukemia with monocytic involvement.

    Matched MeSH terms: Immunophenotyping
  14. Lim J, Razi ZR, Law J, Nawi AM, Idrus RB, Ng MH
    Cytotherapy, 2016 12;18(12):1493-1502.
    PMID: 27727016 DOI: 10.1016/j.jcyt.2016.08.003
    BACKGROUND AIMS: Human Wharton's jelly-derived mesenchymal stromal cells (hWJMSCs) are possibly the most suitable allogeneic cell source for stromal cell therapy and tissue engineering applications because of their hypo-immunogenic and non-tumorigenic properties, easy availability and minimal ethical concerns. Furthermore, hWJMSCs possess unique properties of both adult mesenchymal stromal cells and embryonic stromal cells. The human umbilical cord (UC) is approximately 50-60 cm long and the existing studies in the literature have not provided information on which segment of the UC was studied. In this study, hWJMSCs derived from three anatomical segments of the UC are compared.

    METHODS: Three segments of the whole UC, each 3 cm in length, were identified anatomically as the maternal, middle and fetal segments. The hWJMSCs from the different segments were analyzed via trypan blue exclusion assay to determine the growth kinetics and cell viability, flow cytometry for immunophenotyping and immunofluorescence and reverse transcriptase polymerase chain reaction (RT-PCR) for expression of stromal cell transcriptional factors. Furthermore, the trilineage differentiation potential (osteogenic, adipogenic and chondrogenic) of these cells was also assessed.

    RESULTS: hWJMSCs isolated from the maternal and fetal segments displayed greater viability and possessed a significantly higher proliferation rate compared with cells from the middle segment. Immunophenotyping revealed that hWJMSCs derived from all three segments expressed the MSC markers CD105, CD73, CD90, CD44, CD13 and CD29, as well as HLA-ABC and HLA-DR, but were negative for hematopoietic markers CD14, CD34 and CD45. Analysis of the embryonic markers showed that all three segments expressed Nanog and Oct 3/4, but only the maternal and fetal segments expressed SSEA 4 and TRA-160. Cells from all three segments were able to differentiate into chondrogenic, osteogenic and adipogenic lineages with the middle segments showing much lower differentiation potential compared with the other two segments.

    CONCLUSIONS: hWJMSCs derived from the maternal and fetal segments of the UC are a good source of MSCs compared with cells from the middle segment because of their higher proliferation rate and viability. Fetal and maternal segments are the preferred cell source for bone regeneration.

    Matched MeSH terms: Immunophenotyping
  15. Siar CH, Ng KH
    J Nihon Univ Sch Dent, 1995 Sep;37(3):163-9.
    PMID: 7490610
    The lining epithelium of 15 cases of odontogenic keratocyst (OKC) was evaluated immunohistochemically. The peroxidase-antiperoxidase technique was applied to study the distribution of polyclonal keratin and S-100 protein while the indirect method was used to examine monoclonal vimentin and desmin reactivity. Consistent positive keratin staining was revealed in the lining epithelium of all 15 OKCs with additional intense staining in the stratum corneum. None of the cases showed vimentin or desmin reactivity within the lining epithelium elements. One of the 15 cysts studied showed positive S-100 protein staining in the nuclei of the lining epithelial cells. The pertinent literature on the immunophenotyping of the lining epithelium of OKC is reviewed.
    Matched MeSH terms: Immunophenotyping
  16. Radhakrishnan AK, Lee AL, Wong PF, Kaur J, Aung H, Nesaretnam K
    Br J Nutr, 2009 Mar;101(6):810-5.
    PMID: 18702848 DOI: 10.1017/S0007114508039998
    Vitamin E is divided into two subgroups; tocopherols and tocotrienols. Both have protective roles in biological systems. The present study was conducted to compare the effect of short-term supplementation at 200 mg/d of either alpha-tocopherol or a tocotrienol-rich fraction (TRF) from palm oil on immune modulation and plasma vitamin E levels in normal healthy Asian volunteers. In a randomised, double-blind placebo-controlled trial conducted, fifty-three healthy volunteers aged 20-50 years were recruited based on the study's inclusion and exclusion criteria. They were randomly assigned into three groups, i.e. two experimental groups that received daily supplementation at 200 mg of either alpha-tocopherol or the TRF, and the control group that received a placebo. Blood was drawn on days 0, 28 and 56 for several laboratory analyses. Differences in the production of IL-4 or interferon-gamma by concanavalin A-stimulated lymphocytes isolated from these volunteers were not significant (P>0.05). There were no significant differences observed in immune parameters between the healthy volunteers who received daily supplementation with either alpha-tocopherol or the TRF. As these observations were made in the absence of any immunogenic challenge, we feel it would be of benefit to study if there would be any differences observed when an immunogenic challenge such as vaccination were introduced.
    Matched MeSH terms: Immunophenotyping
  17. Dhaliwal JS, Balasubramaniam T, Quek CK, Gill HK, Nasuruddin BA
    Singapore Med J, 1995 Jun;36(3):288-91.
    PMID: 8553095
    The aim of this study was to establish the lymphocyte subset reference ranges in a defined Malaysian population as well as to determine inter-racial differences for these values. Normal blood obtained from 152 subjects (55.9% Malay, 26.3% Chinese and 17.7% Indian) was immunophenotyped. Results obtained (expressed as mean +/- SD %), absolute count (x 10(6) cells/mm3) were as follows: CD3:66.5 +/- 8.6%, 2,066; CD4:33.2 +/- 8.5%, 1,028; CD831.6 +/- 8.9%, 982; CD19:12.0 +/- 0%, 5,374, and CD56+CD16:20.9 +/- 9%, 1,638. There were no significant differences between the percent lymphocyte subsets of the three racial groups. However, the absolute number of CD4 cells and CD19 cells in Chinese was significantly lower (p < 0.05) compared to the Indian and the Indian and Malay groups respectively. Comparison of our results with other reports showed that the percentage of Natural Killer cells in this population is higher than that reported for Caucasian population.
    Matched MeSH terms: Immunophenotyping
  18. Shanmugam H, Eow GI, Nadarajan VS
    Malays J Pathol, 2009 Jun;31(1):63-6.
    PMID: 19694316 MyJurnal
    Adult T-cell leukaemia/lymphoma (ATLL) is a rare T lymphoproliferative disorder which is aetiologically linked with human T-cell lymphotropic virus type-1 (HTLV-1). HTLV-1 is endemic in Japan, Caribbean and Africa. The highest incidence of ATLL is in Japan although sporadic cases have been reported elsewhere in the world. We describe a case of ATLL with an unusual presentation which we believe is the first reported case of ATLL in Malaysia based on our literature search. A 51-year-old Indian lady was referred to University Malaya Medical Centre for an incidental finding of lymphocytosis while being investigated for pallor and giddiness. Clinical examination revealed bilateral shotty cervical lymph nodes with no hepato-splenomegaly or skin lesions. Laboratory investigations showed absolute lymphocytosis (38 x 10(9)/L) with a mildly increased serum lactate dehydrogenase. The peripheral blood smear showed the presence of predominantly small to medium sized, non-flower lymphocytes. The bone marrow showed similar findings of prominent lymphocytosis. Immunophenotyping of the bone marrow mononuclear cells showed CD3+, CD4+, CD5+, CD7- and CD25+ which is characteristic of ATLL phenotype. HTLV-1 infection was confirmed by the presence of HTLV-1 proviral DNA in the tumor cells using conventional Polymerase Chain Reaction (PCR) and real-time PCR. Here, we discuss the pathogenesis and characteristics of ATLL as well as the detection of HTLV-1 by real time PCR.
    Matched MeSH terms: Immunophenotyping
  19. Abdullah M, Rahman FA, Gnanasegaran N, Govindasamy V, Abu Kasim NH, Musa S
    ScientificWorldJournal, 2014;2014:235941.
    PMID: 24616615 DOI: 10.1155/2014/235941
    Lead (Pb(2+)) exposure continues to be a significant public health problem. Therefore, it is vital to have a continuous epidemiological dataset for a better understanding of Pb(2+) toxicity. In the present study, we have exposed stem cells isolated from deciduous and permanent teeth, periodontal ligament, and bone marrow to five different types of Pb(2+) concentrations (160, 80, 40, 20, and 10 µM) for 24 hours to identify the adverse effects of Pb(2+) on the proliferation, differentiation, and gene expression on these cell lines. We found that Pb(2+) treatment altered the morphology and adhesion of the cells in a dose-dependent manner. There were no significant changes in terms of cell surface phenotypes. Cells exposed to Pb(2+) continued to differentiate into chondrogenesis and adipogenesis, and a severe downregulation was observed in osteogenesis. Gene expression studies revealed a constant expression of key markers associated with stemness (Oct 4, Rex 1) and DNA repair enzyme markers, but downregulation occurred with some ectoderm and endoderm markers, demonstrating an irregular and untimely differentiation trail. Our study revealed for the first time that Pb(2+) exposure not only affects the phenotypic characteristics but also induces significant alteration in the differentiation and gene expression in the cells.
    Matched MeSH terms: Immunophenotyping
  20. Munisvaradass R, Kumar S, Govindasamy C, Alnumair KS, Mok PL
    Int J Mol Sci, 2017 Sep 08;18(9).
    PMID: 28885562 DOI: 10.3390/ijms18091797
    Breast cancer is a common malignancy among women. The innate and adaptive immune responses failed to be activated owing to immune modulation in the tumour microenvironment. Decades of scientific study links the overexpression of human epidermal growth factor receptor 2 (ERBB2) antigen with aggressive tumours. The Chimeric Antigen Receptor (CAR) coding for specific tumour-associated antigens could initiate intrinsic T-cell signalling, inducing T-cell activation, and cytotoxic activity without the need for major histocompatibility complex recognition. This renders CAR as a potentially universal immunotherapeutic option. Herein, we aimed to establish CAR in CD3+ T-cells, isolated from human peripheral blood mononucleated cells that could subsequently target and induce apoptosis in the ERBB2 overexpressing human breast cancer cell line, SKBR3. Constructed CAR was inserted into a lentiviral plasmid containing a green fluorescent protein tag and produced as lentiviral particles that were used to transduce activated T-cells. Transduced CAR-T cells were then primed with SKBR3 cells to evaluate their functionality. Results showed increased apoptosis in SKBR3 cells co-cultured with CAR-T cells compared to the control (non-transduced T-cells). This study demonstrates that CAR introduction helps overcome the innate limitations of native T-cells leading to cancer cell apoptosis. We recommend future studies should focus on in vivo cytotoxicity of CAR-T cells against ERBB2 expressing tumours.
    Matched MeSH terms: Immunophenotyping
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