Displaying publications 61 - 80 of 89 in total

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  1. Altered antibacterial activity of Curcumin in the presence of serum albumin, plasma and whole blood
    Teow SY, Ali SA
    Pak J Pharm Sci, 2017 Mar;30(2):449-457.
    PMID: 28649069
    Antibacterial effect is one of the major therapeutic activities of plant-derived Curcumin. This work evaluated the effect of serum albumin, human plasma, and whole blood on the in vitro activity of Curcumin against eight clinical bacterial isolates by standard broth microdilution and plate-counting methods. Toxicological effects of Curcumin towards human red blood cells (RBCs) and peripheral blood mononuclear cells (PBMCs) were also investigated. Curcumin exhibited weak activity against gram-negative bacteria, except Escherichia coli and Shigella flexneri were susceptible and was most active against gram-positive bacteria: Staphylococcus aureus, Streptococcus pyogenes and Enterococcus faecalis. The antibacterial activity was impaired in the presence of bovine serum albumin (BSA), human plasma and whole blood. Curcumin was not toxic to PBMCs and RBCs at 200μg/mL. Furthermore, Curcumin showed synergistic activity in combination with antibiotics: Ciprofloxacin, Gentamicin, Vancomycin and Amikacin against Staphylococcus aureus. This study demonstrated that the interaction of Curcumin with plasma proteins diminishes its in vitro antibacterial activity. Curcumin derivatives with reduced affinity for plasma protein may improve the bioavailability and antibacterial activities.
    Matched MeSH terms: Leukocytes, Mononuclear/drug effects
  2. Fulltext Conditioned media of pancreatic cancer cells and pancreatic stellate cells induce myeloid-derived suppressor cells differentiation and lymphocytes suppression
    Chong YP, Peter EP, Lee FJM, Chan CM, Chai S, Ling LPC, et al.
    Sci Rep, 2022 Jul 19;12(1):12315.
    PMID: 35853996 DOI: 10.1038/s41598-022-16671-9
    As pancreatic cancer cells (PCCs) and pancreatic stellate cells (PSCs) are the two major cell types that comprise the immunosuppressive tumor microenvironment of pancreatic cancer, we aimed to investigate the role of conditioned medium derived from PCCs and PSCs co-culture on the viability of lymphocytes. The conditioned medium (CM) collected from PCCs and/or PSCs was used to treat peripheral blood mononuclear cells (PBMCs) to determine CM ability in reducing lymphocytes population. A proteomic analysis has been done on the CM to investigate the differentially expressed protein (DEP) expressed by two PCC lines established from different stages of tumor. Subsequently, we investigated if the reduction of lymphocytes was directly caused by CM or indirectly via CM-induced MDSCs. This was achieved by isolating lymphocyte subtypes and treating them with CM and CM-induced MDSCs. Both PCCs and PSCs were important in suppressing lymphocytes, and the PCCs derived from a metastatic tumor appeared to have a stronger suppressive effect than the PCCs derived from a primary tumor. According to the proteomic profiles of CM, 416 secreted proteins were detected, and 13 DEPs were identified between PANC10.05 and SW1990. However, CM was found unable to reduce lymphocytes viability through a direct pathway. In contrast, CM that contains proteins secreted by PCC and/or PSC appear immunogenic as they increase the viability of lymphocytes subtypes. Lymphocyte subtype treated with CM-induced MDSCs showed reduced viability in T helper 1 (Th1), T helper 2 (Th2), and T regulatory (Treg) cells, but not in CD8+ T cells, and B cells. As a conclusion, the interplay between PCCs and PSCs is important as their co-culture displays a different trend in lymphocytes suppression, hence, their co-culture should be included in future studies to better mimic the tumor microenvironment.
    Matched MeSH terms: Leukocytes, Mononuclear/metabolism
  3. How the immune mousetrap works: Structural evidence for the immunomodulatory action of a peptide from influenza NS1 protein
    Zabrodskaya Y, Tsvetkov V, Shurygina AP, Vasyliev K, Shaldzhyan A, Gorshkov A, et al.
    Biophys Chem, 2024 Apr;307:107176.
    PMID: 38219420 DOI: 10.1016/j.bpc.2024.107176
    One of the critical stages of the T-cell immune response is the dimerization of the intramembrane domains of T-cell receptors (TCR). Structural similarities between the immunosuppressive domains of viral proteins and the transmembrane domains of TCR have led several authors to hypothesize the mechanism of immune response suppression by highly pathogenic viruses: viral proteins embed themselves in the membrane and act on the intramembrane domain of the TCRalpha subunit, hindering its functional oligomerization. It has also been suggested that this mechanism is used by influenza A virus in NS1-mediated immunosuppression. We have shown that the peptide corresponding to the primary structure of the potential immunosuppressive domain of NS1 protein (G51) can reduce concanavalin A-induced proliferation of PBMC cells, as well as in vitro, G51 can affect the oligomerization of the core peptide corresponding to the intramembrane domain of TCR, using AFM and small-angle neutron scattering. The results obtained using in cellulo and in vitro model systems suggest the presence of functional interaction between the NS1 fragment and the intramembrane domain of the TCR alpha subunit. We have proposed a possible scheme for such interaction obtained by computer modeling. This suggests the existence of another NS1-mediated mechanism of immunosuppression in influenza.
    Matched MeSH terms: Leukocytes, Mononuclear/metabolism
  4. Autoimmune lymphoproliferative syndrome caused by a homozygous FasL mutation that disrupts FasL assembly
    Sobh A, Crestani E, Cangemi B, Kane J, Chou J, Pai SY, et al.
    J Allergy Clin Immunol, 2016 Jan;137(1):324-327.e2.
    PMID: 26456038 DOI: 10.1016/j.jaci.2015.08.025
    Matched MeSH terms: Leukocytes, Mononuclear/metabolism
  5. The inhibition of human T cell proliferation by the caspase inhibitor z-VAD-FMK is mediated through oxidative stress
    Rajah T, Chow SC
    Toxicol Appl Pharmacol, 2014 Jul 15;278(2):100-6.
    PMID: 24768707 DOI: 10.1016/j.taap.2014.04.014
    The caspase inhibitor benzyloxycarbony (Cbz)-l-Val-Ala-Asp (OMe)-fluoromethylketone (z-VAD-FMK) has recently been shown to inhibit T cell proliferation without blocking caspase-8 and caspase-3 activation in primary T cells. We showed in this study that z-VAD-FMK treatment leads to a decrease in intracellular glutathione (GSH) with a concomitant increase in reactive oxygen species (ROS) levels in activated T cells. The inhibition of anti-CD3-mediated T cell proliferation induced by z-VAD-FMK was abolished by the presence of low molecular weight thiols such as GSH, N-acetylcysteine (NAC) and l-cysteine, whereas d-cysteine which cannot be metabolised to GSH has no effect. These results suggest that the depletion of intracellular GSH is the underlying cause of z-VAD-FMK-mediated inhibition of T cell activation and proliferation. The presence of exogenous GSH also attenuated the inhibition of anti-CD3-induced CD25 and CD69 expression mediated by z-VAD-FMK. However, none of the low molecular weight thiols were able to restore the caspase-inhibitory properties of z-VAD-FMK in activated T cells where caspase-8 and caspase-3 remain activated and processed into their respective subunits in the presence of the caspase inhibitor. This suggests that the inhibition of T cell proliferation can be uncoupled from the caspase-inhibitory properties of z-VAD-FMK. Taken together, the immunosuppressive effects in primary T cells mediated by z-VAD-FMK are due to oxidative stress via the depletion of GSH.
    Matched MeSH terms: Leukocytes, Mononuclear/drug effects; Leukocytes, Mononuclear/immunology; Leukocytes, Mononuclear/metabolism
  6. Fulltext Association of angiogenic cells in the tumour microenvironment and the circulating matured endothelial cells in astrocytic glioma
    Das, Priscilla, Naing, Nyi Nyi, Nadiah Wan-Arfah, Noorjan, KON, Yee, Cheng Kueh, Rasalingam, Kantha
    International Medical Journal Malaysia, 2018;17(2):3-10.
    MyJurnal
    Introduction: Astrocytic gliomas are the most common and lethal intracranial brain tumours and rely on angiogenesis for the tumour development. Endothelial progenitor cells (EPCs) contribute to the angiogenesis of glioma tumour. Objectives: The study aimed to investigate the matured circulating endothelial cells population in the peripheral blood mononuclear cells (PBMCs) and its associations with tissue resident angiogenic cells in astrocytic glioma patients. Methods: A total of 22 astrocytic glioma patients were recruited from Hospital Universiti Sains Malaysia. Tumour were sliced and stained with CD133+ and VEGFA+ for angiogenic cells (n=22). The circulating (CD133-/VEGFR2+) matured endothelial cells in PBMCs (n=22) were quantified using FACS. The paired t-test and Pearson correlation test were used for the data analysis. Results: The angiogenic cells in brain tumour tissue were significantly higher compared to adjacent normal brain tissue (median 1.07±0.96% vs. median 0.69±0.68%; Wilcoxon signed rank test Z=-3.100; p=0.002). Positive correlation was found between the angiogenic cells of brain tumour tissue and adjacent normal brain tissue (Spearman’s rho correlation test, r=0.56; p=0.007). Significant positive correlation was found between matured endothelial cells in peripheral circulating systems and angiogenic cells in tumour of astrocytic glioma patients (Pearson correlation test, r=0.60, p=0.003).Conclusion:The findings of the study give support to the possible roles of EPCs in astrocytic glioma patients. Thus targeting tissue resident angiogenic cells and matured circulating endothelial cells by antiangiogenic treatment might be useful to prevent the tumour growth.
    Matched MeSH terms: Leukocytes, Mononuclear
  7. Fulltext Characterization of Occult Hepatitis C Virus (HCV) infection among Hemodialysis patient
    Siti Nurul Fazlin Abdul Rahman, Hairul Aini Hamzah, Mohammed Imad Mustafa, Mohamed Hadzri Hasmoni
    International Medical Journal Malaysia, 2017;16(11):22-22.
    MyJurnal
    The existence of new entity called occult hepatitis C virus (HCV) has
    become a raising and escalating concern among healthcare professionals worldwide. It
    is defined by the presence of viral RNA in liver and/or peripheral blood mononuclear
    cells (PBMCs) within non HCV-infected patients. Previous study had shown the occult
    HCV is infectious and capable of transmitting the virus to another host. Till today, HCV
    infection remains common among hemodialysis patients despite having the best
    preventive plans. Because of this, there is a significant concern about the source of viral
    transmission. The aim of the study was to identify and characterize occult HCV infection
    in PBMC sample of hemodialysis patients. This was an observational and cross sectional
    study. (Copied from article).
    Matched MeSH terms: Leukocytes, Mononuclear
  8. Fulltext Association of tumor angiogenic cells (cd133+/vegfa+) and circulating cancer stem cells (cd133+/vegfr2-) in astrocytic glioma patients
    Das, P., Naing, N.N., Wan-Arfah, N., Noorjan, K., Kueh, Y.C., Rasalingam, K.
    JUMMEC, 2019;22(2):31-38.
    MyJurnal
    Background: Astrocytic gliomas are the most common primary brain tumors that developed from glial origin.
    The angiogenic cell population from brain tumor enhances the recruitment of circulating cancer stem cells
    homing towards tumor site.

    Objectives: This study aimed to investigate the tumor angiogenic cell population that stained with CD133+
    and VEGFA+ markers and its association with circulating cancer stem cell (CD133+/VEGFR2-) population in the
    peripheral blood mononuclear cells (PBMCs) of astrocytic glioma patients.

    Methods: A total of 22 astrocytic glioma patients from Hospital Universiti Sains Malaysia who consented to
    the study were included. Tumors (n=22) were sliced and stained with CD133+ and VEGFA+ angiogenic markers
    and counter stained with DAPI. The circulating cancer stem cells (CD133+/VEGFR2-) in PBMCs (n=22) were
    quantified using FACS based on the expression of CD133 and VEGFR2 markers. The paired t-test and Pearson
    correlation were used for the data analysis.

    Results: The percentage of angiogenic cell population was significantly higher in brain tumor compared to
    adjacent normal brain tissue (1.25 ± 0.96% vs. 0.74 ± 0.68%; paired t-test=2.855; df=21, p = 0.009). Positive
    correlation was found between the angiogenic cells of brain tumor tissue and adjacent normal brain tissue
    (Pearson correlation, r = 0.53, p = 0.011). Significant positive correlation was found between angiogenic cells
    in glioma tumor and cancer stem cells in peripheral circulating systems of astrocytic glioma patients (Pearson
    correlation, r = 0.42, p = 0.049).

    Conclusion: Angiogenic cells in the brain tumor resident promote the recruitment of circulating cancer stem cells
    homing to the tumor site and induce the proliferation and growth of the tumor in astrocytic glioma patients.
    Matched MeSH terms: Leukocytes, Mononuclear
  9. Safety and immunogenicity of a prefusion non-stabilized spike protein mRNA COVID-19 vaccine: a phase I trial
    Gatechompol S, Kittanamongkolchai W, Ketloy C, Prompetchara E, Thitithanyanont A, Jongkaewwattana A, et al.
    Nat Microbiol, 2022 Dec;7(12):1987-1995.
    PMID: 36376393 DOI: 10.1038/s41564-022-01271-0
    Effective mRNA SARS-CoV-2 vaccines are available but need to be stored in freezers, limiting their use to countries that have appropriate storage capacity. ChulaCov19 is a prefusion non-stabilized SARS-CoV-2 spike-protein-encoding, nucleoside-modified mRNA, lipid nanoparticle encapsulated vaccine that we report to be stable when stored at 2-8 °C for up to 3 months. Here we report safety and immunogenicity data from a phase I open-label, dose escalation, first-in-human trial of the ChulaCov19 vaccine (NCT04566276). Seventy-two eligible volunteers, 36 of whom were aged 18-55 (adults) and 36 aged 56-75 (elderly), were enroled. Two doses of vaccine were administered 21 d apart at 10, 25 or 50 μg per dose (12 per group). The primary outcome was safety and the secondary outcome was immunogenicity. All three dosages of ChulaCov19 were well tolerated and elicited robust dose-dependent and age-dependent B- and T-cell responses. Transient mild/moderate injection site pain, fever, chills, fatigue and headache were more common after the second dose. Four weeks after the second dose, in the adult cohort, MicroVNT-50 geometric mean titre against wild-type SARS-CoV-2 was 848 (95% CI, 483-1,489), 736 (459-1,183) and 1,140 (854-1,522) IU ml-1 at 10, 25 and 50 μg doses, respectively, versus 285 (196-413) IU ml-1 for human convalescent sera. All dose levels elicited 100% seroconversion, with geometric mean titre ratios 4-8-fold higher than for human convalescent sera (P mononuclear cells. The 50 μg dose induced better cross-neutralization against Alpha, Beta, Gamma and Delta variants than lower doses. ChulaCov19 at 50 μg is well tolerated and elicited higher neutralizing antibodies than human convalescent sera, with strong T-cell responses. These antibodies cross-neutralized four variants of concern. ChulaCov19 has proceeded to phase 2 clinical trials. We conclude that the mRNA vaccine expressing a prefusion non-stabilized spike protein is safe and highly immunogenic.
    Matched MeSH terms: Leukocytes, Mononuclear
  10. Fulltext Functional Polymorphisms of the Arachidonic Acid Pathway Associate with Risks and Clinical Outcomes of Allergic Diseases
    Sio YY, Shi P, Matta SA, Fok YTR, Chiang WC, Say YH, et al.
    Int Arch Allergy Immunol, 2023;184(6):609-623.
    PMID: 37231900 DOI: 10.1159/000530393
    INTRODUCTION: The arachidonic acid (AA) pathway plays a crucial role in allergic inflammatory diseases; however, the functional roles of allergy-associated single nucleotide polymorphisms (SNPs) in this pathway remain incompletely illustrated.

    METHODS: This study belongs to a part of an ongoing Singapore/Malaysia cross-sectional genetics and epidemiological study (SMCSGES). We performed population genotyping on n = 2,880 individuals from the SMCSGES cohort to assess the associations of SNPs in the AA pathway genes with asthma and allergic rhinitis (AR). Spirometry assessments were performed to identify associations between SNPs and lung function among n = 74 pediatric asthmatic patients from the same cohort. Allergy-associated SNPs were functionally characterized using in vitro promoter luciferase assay, along with DNA methylome and transcriptome data of n = 237 peripheral blood mononuclear cell (PBMC) samples collected from a subset of the SMCSGES cohort.

    RESULTS: Genetic association analysis showed 5 tag-SNPs from 4 AA pathway genes were significantly associated with asthma (rs689466 at COX2, rs35744894 at hematopoietic PGD2 synthase (HPGDS), rs11097414 at HPGDS, rs7167 at CRTH2, and rs5758 at TBXA2R, p < 0.05), whereas 3 tag-SNPs from HPGDS (rs35744894, rs11097414, and rs11097411) and 2 tag-SNPs from PTGDR (rs8019916 and rs41312470) were significantly associated with AR (p < 0.05). The asthma-associated rs689466 regulates COX2 promoter activity and associates with COX2 mRNA expression in PBMC. The allergy-associated rs1344612 was significantly associated with poorer lung function, increased risks of asthma and AR, and increased HPGDS promoter activity. The allergy-associated rs8019916 regulates PTGDR promoter activity and DNA methylation levels of cg23022053 and cg18369034 in PBMC. The asthma-associated rs7167 affects CRTH2 expression by regulating the methylation level of cg19192256 in PBMC.

    CONCLUSIONS: The present study identified multiple allergy-associated SNPs that modulate the transcript expressions of key genes in the AA pathway. The development of a "personalized medicine" approach with consideration of genetic influences on the AA pathway may hopefully result in efficacious strategies to manage and treat allergic diseases.

    Matched MeSH terms: Leukocytes, Mononuclear
  11. In-vitro antimalarial activity of methanolic leaf- and stem-derived extracts from four Annonaceae plants
    Lithanatudom P, Chawansuntati K, Saenjum C, Chaowasku T, Rattanathammethee K, Wungsintaweekul B, et al.
    BMC Res Notes, 2023 Dec 22;16(1):381.
    PMID: 38135870 DOI: 10.1186/s13104-023-06664-w
    OBJECTIVE: Plants in the Annonaceae family are known for having abundant biologically active secondary metabolites. They have been used in alternative drugs for various diseases in several countries, for instance, the bark of Cananga odorata (Lam.) Hook and Thomson is used for Ophthalmic inflammation and wound healing in Malaysia. Extracts from the leaves and stems of four Annonaceae plants, namely Uvaria longipes (Craib) L.L.Zhou, Y.C.F.Su & R.M.K.Saunders, Dasymaschalon sp., Artabotrys burmanicus A.DC, and Marsypopetalum modestum (Pierre) B.Xue & R.M.K.Saunders were investigated for growth inhibitory activity against blood-stage Plasmodium falciparum growth in vitro and for non-specific cytotoxicity against normal peripheral blood mononuclear cells (PBMCs). Antimalarial activity was assessed by invasion inhibition assay and the percentage of infected red blood cells on blood smears were determined. Cytotoxicity was tested by culturing PBMCs with the extracts, and viabilities were determined by Annexin V/propidium iodide staining.

    RESULTS: A. burmanicus stem extract and M. modestum leaf extract were capable of inhibiting growth of P. falciparum when used at 200 µg/mL compared to chloroquine. The extracts at effective concentrations, did not affect the viability of PBMCs. These results support further need for characterization of active compounds from specific Annonaceae plants in order to exploit their components for potential malaria treatment.

    Matched MeSH terms: Leukocytes, Mononuclear
  12. Inhibitory effect of selected medicinal plants on the release of pro-inflammatory cytokines in lipopolysaccharide-stimulated human peripheral blood mononuclear cells
    Salim E, Kumolosasi E, Jantan I
    J Nat Med, 2014 Jul;68(3):647-53.
    PMID: 24799081 DOI: 10.1007/s11418-014-0841-0
    The inhibitory activities of the methanol extracts from 20 selected medicinal plants on the release of pro-inflammatory cytokines in human peripheral blood mononuclear cells (PBMCs) were evaluated. The major compound from the most active plant extract was also investigated. The inhibitory effect of the methanol extracts on the release of pro-inflammatory cytokines was tested by incubating PBMCs with the sample and then stimulating by lipopolysaccharide at 0.1 μg/ml. The level of cytokines was determined using enzyme-linked immunosorbent assay. Among the extracts tested, Andrographis paniculata extract demonstrated the strongest inhibition of interleukin (IL)-1β, IL-1α, and IL-6 release, with IC50 values of 1.54, 1.06, and 0.74 μg/ml, respectively. The IC50 value of A. paniculata extract was significantly higher than that of andrographolide on IL-1α, IL-1β, and IL-6 (p 
    Matched MeSH terms: Leukocytes, Mononuclear/drug effects*; Leukocytes, Mononuclear/immunology
  13. Ascorbic acid induces osteoblast differentiation of human suspension mononuclear cells
    Hadzir SN, Ibrahim SN, Abdul Wahab RM, Zainol Abidin IZ, Senafi S, Ariffin ZZ, et al.
    Cytotherapy, 2014 May;16(5):674-82.
    PMID: 24176546 DOI: 10.1016/j.jcyt.2013.07.013
    Suspension mononuclear cells (MNCs) can be differentiated into osteoblasts with the induction of ascorbic acid and β-glycerophosphate. The aim of this study was to determine the ability of suspension MNCs to differentiate into osteoblasts using ascorbic acid only.
    Matched MeSH terms: Leukocytes, Mononuclear/cytology*; Leukocytes, Mononuclear/drug effects*
  14. Effect of Rhaphidophora korthalsii methanol extract on human peripheral blood mononuclear cell (PBMC) proliferation and cytolytic activity toward HepG2
    Yeap SK, Alitheen NB, Ali AM, Omar AR, Raha AR, Suraini AA, et al.
    J Ethnopharmacol, 2007 Dec 3;114(3):406-11.
    PMID: 17884317
    The study of bioactivity of natural product is one of the major researches for drug discovery. The aim of this finding was to study the proliferation effect of Rhaphidophora korthalsii methanol extract on human PBMC and subsequently the cytotoxic effect of activated PBMC toward HepG2 human hepatocellular carcinoma. In this present study, MTT assay, cell cycle study and Annexin 5 binding assay were used to study the immunomodulatory and cytotoxic effects. In vitro cytotoxic screening of Rhaphidophora korthalsii methanol extract showed that the extract was non-toxic against hepatocellular carcinoma (HepG2). In contrast, the extract was able to stimulate the proliferation of human PBMC at 48 h and 72 h in MTT assay and cell cycle progress study. The application of immunomodulator in tumor research was studied by using MTT microcytotoxicity assay and flow cytometric Annexin V. Results indicated that pre-treated PBMC with Rhaphidophora korthalsii methanol extract induced the highest cytotoxicity (44.87+/-6.06% for MTT microcytotoxicity assay and 51.51+/-3.85% for Annexin V) toward HepG2. This finding demonstrates that Rhaphidophora korthalsii methanol extract are potent to stimulate the cytotoxic effect of immune cells toward HepG2.
    Matched MeSH terms: Leukocytes, Mononuclear/drug effects*; Leukocytes, Mononuclear/immunology
  15. Antioxidant enzyme activities of human peripheral blood mononuclear cells exposed to trace elements
    Kuppusamy UR, Dharmani M, Kanthimathi MS, Indran M
    Biol Trace Elem Res, 2005 Jul;106(1):29-40.
    PMID: 16037608
    The trace elements copper, zinc, and selenium are important immune modulators and essential cofactors of the antioxidant enzymes. In the present study, the proliferative effect of human peripheral mononuclear cells (PBMCs) that have been exposed to copper, zinc, and selenium and the corresponding activities of antioxidant enzymes, namely superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase, were determined. Zinc and copper stimulated the PBMC proliferation in a dose-dependent manner within the dose range 25-200 micromol/L. SOD and GPx activities in PBMCs exposed to zinc were inhibited, whereas catalase activity was unaffected. All the three antioxidant enzymes in the cells exposed to copper were inhibited. Selenium exerted more potent inhibition of the cell proliferation while causing stimulation of the antioxidant enzymes at the lowest dose (25 micromol/L) than at the highest dose (200 micromol/L) tested. A significant negative correlation was observed between proliferation and antioxidant enzyme (SOD and GPx) activities in trace-element-exposed PBMC. The present findings substantiate the importance of trace elements as immune modulators and the involvement of enzymatic antioxidant system in the immune cell regulation.
    Matched MeSH terms: Leukocytes, Mononuclear/cytology*; Leukocytes, Mononuclear/drug effects*
  16. Fulltext Effects of annexin A1 on apoptosis and cell cycle arrest in human leukemic cell lines
    Sabran A, Kumolosasi E, Jantan I
    Acta Pharm, 2019 Mar 01;69(1):75-86.
    PMID: 31259717 DOI: 10.2478/acph-2019-0005
    Recent studies suggest that annexin A1 (ANXA1) promotes apoptosis in cancerous cells. This study aims to investigate the effects of ANXA1 on apoptosis and cell cycle arrest in K562, Jurkat and U937 cells and peripheral blood mononu-clear cells (PBMC). Cells were treated with ANXA1 and cyclophosphamide prior to flow cytometry analysis for apoptosis and cell cycle arrest induction. At 2.5µM, ANXA1 induced significant apoptosis in K562 (p ≤ 0.001) and U937 (p ≤ 0.05) cells, with EC50 values of 3.6 and 3.8 µM, respectively. In Jurkat cells, induction was not significant (EC50, 17.0 µM). No significant apoptosis induction was observed in PBMC. ANXA1 caused cycle arrest in the G0/G1 phase in K562 and U937 cells with p ≤ 0.001 for both, and (p ≤ 0.01) for Jurkat cells. ANXA1 induced apoptosis and cycle arrest in the G0/G1 phase in K562 and U937 cells, causing only cell cycle arrest in Jurkat cells.
    Matched MeSH terms: Leukocytes, Mononuclear/metabolism*; Leukocytes, Mononuclear/physiology*
  17. Fulltext Senescence-related changes in gene expression of peripheral blood mononuclear cells from octo/nonagenarians compared to their offspring
    Abdul Rahman A, Abdul Karim N, Abdul Hamid NA, Harun R, Ngah WZ
    Oxid Med Cell Longev, 2013;2013:189129.
    PMID: 24381713 DOI: 10.1155/2013/189129
    Mechanisms determining both functional rate of decline and the time of onset in aging remain elusive. Studies of the aging process especially those involving the comparison of long-lived individuals and young controls are fairly limited. Therefore, this research aims to determine the differential gene expression profile in related individuals from villages in Pahang, Malaysia. Genome-wide microarray analysis of 18 samples of peripheral blood mononuclear cells (PBMCs) from two groups: octo/nonagenarians (80-99 years old) and their offspring (50.2 ± 4.0 years old) revealed that 477 transcripts were age-induced and 335 transcripts were age-repressed with fold changes ≥1.2 in octo/nonagenarians compared to offspring. Interestingly, changes in gene expression were associated with increased capacity for apoptosis (BAK1), cell cycle regulation (CDKN1B), metabolic process (LRPAP1), insulin action (IGF2R), and increased immune and inflammatory response (IL27RA), whereas response to stress (HSPA8), damage stimulus (XRCC6), and chromatin remodelling (TINF2) pathways were downregulated in octo/nonagenarians. These results suggested that systemic telomere maintenance, metabolism, cell signalling, and redox regulation may be important for individuals to maintain their healthy state with advancing age and that these processes play an important role in the determination of the healthy life-span.
    Matched MeSH terms: Leukocytes, Mononuclear/cytology*; Leukocytes, Mononuclear/metabolism*
  18. An electronmicroscopic study of the interaction of Burkholderia pseudomallei and human macrophages
    Nathan SA, Puthucheary SD
    Malays J Pathol, 2005 Jun;27(1):3-7.
    PMID: 16676686
    B. pseudomallei has been shown to persist intracellularly in melioidosis patients until reactivated by decreasing immunocompetence. We have shown by transmission electron microscopy the internalization of B. pseudomallei by human macrophages via conventional phagocytosis enclosed within membrane-bound vacuoles or phagosomes. Ferritin labeled lysosomes provided evidence of phagosome-lysosome fusion. Ingested bacilli were designated as "intact" or "damaged" on the basis of their ultrastructural features. An intact bacterium was seen with low electron opaque central nuclear region surrounded by dense bacterial cytoplasm, bounded externally by bacterial plasma membrane and cell wall. In contrast, B. pseudomallei were considered damaged when seen with cavitation within the central nuclear region, separation of bacterial cytoplasm from the cell wall, herniation of cytoplasmic contents and lamination of bacterial cell wall and its surrounding electron transparent zone. Our observations indicate that the microbicidal mechanism(s) in B. pseudomallei-infected macrophages failed to ensure complete clearance of the organism and this failure probably facilitates intracellular persistence and proliferation, and this may be one of the survival strategies adopted by this organism.
    Matched MeSH terms: Leukocytes, Mononuclear/physiology*; Leukocytes, Mononuclear/ultrastructure*
  19. Repetitive cryotherapy attenuates the in vitro and in vivo mononuclear cell activation response
    Lindsay A, Othman MI, Prebble H, Davies S, Gieseg SP
    Exp Physiol, 2016 07 01;101(7):851-65.
    PMID: 27094349 DOI: 10.1113/EP085795
    What is the central question of this study? Acute and repetitive cryotherapy are routinely used to accelerate postexercise recovery, although the effect on resident immune cells and repetitive exposure has largely been unexplored and neglected. What is the main finding and its importance? Using blood-derived mononuclear cells and semi-professional mixed martial artists, we show that acute and repetitive cryotherapy reduces the in vitro and in vivo T-cell and monocyte activation response whilst remaining independent of the physical performance of elite athletes. We investigated the effect of repetitive cryotherapy on the in vitro (cold exposure) and in vivo (cold water immersion) activation of blood-derived mononuclear cells following high-intensity exercise. Single and repeated cold exposure (5°C) of a mixed cell culture (T cells and monocytes) was investigated using in vitro tissue culture experimentation for total neopterin production (neopterin plus 7,8-dihydroneopterin). Fourteen elite mixed martial art fighters were also randomly assigned to either a cold water immersion (15 min at 10°C) or passive recovery protocol, which they completed three times per week during a 6 week training camp. Urine was collected and analysed for neopterin and total neopterin three times per week, and perceived soreness, fatigue, physical performance (broad jump, push-ups and pull-ups) and training performance were also assessed. Single and repetitive cold exposure significantly (P 
    Matched MeSH terms: Leukocytes, Mononuclear/metabolism; Leukocytes, Mononuclear/physiology*
  20. Intracellular antigen determination by flow cytometry in leukaemic cells
    Chin SF, Cheong SK
    Malays J Pathol, 1994 Jun;16(1):69-73.
    PMID: 16329579
    Several fixation and permeabilization techniques that enable the flow cytometric analysis of the cell contents have been introduced in recent years. These methods allow sensitive detection of intracellular antigens that facilitates the diagnosis of certain diseases. We have undertaken in this study to evaluate a simple method of fixation and permeabilization using 2% paraformaldehyde and Tween 20. Intracellular antigens in three different leukaemia cases were analysed. We found that the method was reliable and easy. Intracellular kappa light chains were found in abundance in a case of plasma cell leukaemia. CD3 and CD22 were found in greater amount intracellularly than on the surface in pre-T-ALL and pre-pre B-ALL respectively.
    Matched MeSH terms: Leukocytes, Mononuclear/immunology; Leukocytes, Mononuclear/pathology
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