Displaying publications 41 - 60 of 89 in total

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  1. Bioassay-guided identification of an anti-inflammatory prenylated acylphloroglucinol from Melicope ptelefolia and molecular insights into its interaction with 5-lipoxygenase
    Shaari K, Suppaiah V, Wai LK, Stanslas J, Tejo BA, Israf DA, et al.
    Bioorg Med Chem, 2011 Nov 1;19(21):6340-7.
    PMID: 21958738 DOI: 10.1016/j.bmc.2011.09.001
    A bioassay-guided investigation of Melicope ptelefolia Champ ex Benth (Rutaceae) resulted in the identification of an acyphloroglucinol, 2,4,6-trihydroxy-3-geranylacetophenone or tHGA, as the active principle inhibiting soybean 15-LOX. The anti-inflammatory action was also demonstrated on human leukocytes, where the compound showed prominent inhibitory activity against human PBML 5-LOX, with an IC(50) value of 0.42 μM, very close to the effect produced by the commonly used standard, NDGA. The compound concentration-dependently inhibited 5-LOX product synthesis, specifically inhibiting cysteinyl leukotriene LTC(4) with an IC(50) value of 1.80 μM, and showed no cell toxicity effects. The anti-inflammatory action does not seem to proceed via redox or metal chelating mechanism since the compound tested negative for these bioactivities. Further tests on cyclooxygenases indicated that the compound acts via a dual LOX/COX inhibitory mechanism, with greater selectivity for 5-LOX and COX-2 (IC(50) value of 0.40 μM). The molecular features that govern the 5-LOX inhibitory activity was thus explored using in silico docking experiments. The residues Ile 553 and Hie 252 were the most important residues in the interaction, each contributing significant energy values of -13.45 (electrostatic) and -5.40 kcal/mol (electrostatic and Van der Waals), respectively. The hydroxyl group of the phloroglucinol core of the compound forms a 2.56Å hydrogen bond with the side chain of the carboxylate group of Ile 553. Both Ile 553 and Hie 252 are crucial amino acid residues which chelate with the metal ion in the active site. Distorting the geometry of these ligands could be the reason for the inhibition activity shown by tHGA. The molecular simulation studies supported the bioassay results and served as a good model for understanding the way tHGA binds in the active site of human 5-LOX enzyme.
    Matched MeSH terms: Leukocytes, Mononuclear/enzymology
  2. The predictive value of uvulo-palatoglossal junctional ulcers as an early clinical sign of exanthem subitum due to human herpesvirus 6
    Chua KB, Lam SK, AbuBakar S, Lim ST, Paranjothy M, Koh MT, et al.
    J Clin Virol, 2000 Aug;17(2):83-90.
    PMID: 10942088
    BACKGROUND: The clinical sign of uvulo-palatoglossal junctional (UPJ) ulcers was first noted in 1983 in a 5.5-month-old baby with exanthem subitum (ES). An earlier prospective clinical study showed that there was a strong association of UPJ ulcers and occurrence of ES with a positive predictive value of 95.3% and negative predictive value of 100%.

    OBJECTIVE: To determine the value of uvulo-palatoglossal junctional (UPJ) ulcers as an early clinical sign of exanthem subitum (ES) due to human herpesvirus 6 (HHV 6) infection.

    STUDY DESIGN: A case-control study of 20 febrile children with UPJ ulcers versus 26 febrile children without UPJ ulcers. These children were followed up for any development of ES and investigated for human herpesvirus 6 (HHV 6) as the causative agents of the febrile episodes.

    RESULTS: In this study, 20 out of 46 febrile children aged 3 months to 3 years with UPJ ulcers were virologically and/or serologically confirmed to be due to primary HHV 6 infection. The rest of the 26 children without ulcers did not have HHV 6 infection. Of the 20 children with UPJ ulcers, only 17 of the 19 children with adequate follow-up till subsidence of fever developed ES. None of the 26 children without UPJ ulcers developed ES.

    CONCLUSION: Statistically, there was a significant association of UPJ ulcers as an early sign of ES with a positive predictive value of 89.5% and negative predictive value of 100%. This finding also suggests that the presence of UPJ ulcers is a useful pathognomic clinical sign of symptomatic primary HHV 6 infection.

    Matched MeSH terms: Leukocytes, Mononuclear/virology
  3. Fulltext Single nucleotide polymorphism in the promoter of the human interleukin-13 gene is associated with asthma in Malaysian adults
    Radhakrishnan AK, Raj VL, Tan LK, Liam CK
    Biomed Res Int, 2013;2013:981012.
    PMID: 23865080 DOI: 10.1155/2013/981012
    Asthma susceptibility genes are mapped to a region on human chromosome 5q31-q33, which contains a cluster of proinflammatory cytokine genes such as interleukin-13 (IL-13), which is associated with asthma. This study investigated the allele frequencies of two single nucleotide polymorphisms (SNPs) (-1111C>T and 4257C>A) in the IL-13 gene between asthmatics and healthy volunteers as well as the relationship between these SNPs and IL-13 production. DNA extracted from buffy coat of asthmatic and control subjects was genotyped using the PCR-RFLP method. Amount of IL-13 produced by mitogen-stimulated peripheral blood leucocytes PBLs (PBLs) was determined by ELISA. The frequencies of the -1111C and 4257G wild-type alleles were 0.52 and 0.55 in asthmatics and were 0.67 and 0.56 in controls. A significant (P < 0.05) association was found between genotype and allele frequencies of SNP at position -1111C>T between asthmatic and control groups (OR, 1.810; 95% CI = 1.184 to 2.767; P < 0.05). The mitogen-stimulated PBLs from asthmatics produced higher amounts of IL-13 production (P < 0.001). The 4257GA heterozygous and 4257AA homozygous mutant alleles were associated with higher IL-13 production in asthmatics (P < 0.05). Our results show that the -1111T mutant allele are associated with asthma and the 4257A mutant alleles are associated with elevated IL-13 production.
    Matched MeSH terms: Leukocytes, Mononuclear/metabolism
  4. Fulltext In vitro evaluation of dual-antigenic PV1 peptide vaccine in head and neck cancer patients
    Chai SJ, Fong SCY, Gan CP, Pua KC, Lim PVH, Lau SH, et al.
    Hum Vaccin Immunother, 2019;15(1):167-178.
    PMID: 30193086 DOI: 10.1080/21645515.2018.1520584
    Peptide vaccines derived from tumour-associated antigens have been used as an immunotherapeutic approach to induce specific cytotoxic immune response against tumour. We previously identified that MAGED4B and FJX1 proteins are overexpressed in HNSCC patients; and further demonstrated that two HLA-A2-restricted 9-11 amino acid peptides derived from these proteins were able to induce anti-tumour immune responses in vitro independently using PBMCs isolated from these patients. In this study, we evaluated the immunogenicity and efficacy of a dual-antigenic peptide vaccine (PV1), comprised of MAGED4B and FJX1 peptides in HNSCC patients. We first demonstrated that 94.8% of HNSCC patients expressed MAGED4B and/or FJX1 by immunohistochemistry, suggesting that PV1 could benefit the majority of HNSCC patients. The presence of pre-existing MAGED4B and FJX1-specific T-cells was detected using a HLA-A2 dimer assay and efficacy of PV1 to induce T-cell to secrete cytotoxic cytokine was evaluated using ELISPOT assay. Pre-existing PV1-specific T-cells were detected in all patients. Notably, we demonstrated that patients' T-cells were able to secrete cytotoxic cytokines upon exposure to target cells expressing the respective antigen post PV1 stimulation. Furthermore, patients with high expression of MAGED4B and FJX1 in their tumours were more responsive to PV1 stimulation, demonstrating the specificity of the PV1 peptide vaccine. Additionally, we also demonstrated the expression of MAGED4B and FJX1 in breast, lung, colon, prostate and rectal cancer suggesting the potential use of PV1 in these cancers. In summary, PV1 could be a good vaccine candidate for the treatment of HNSCC patients and other cancers expressing these antigens.
    Matched MeSH terms: Leukocytes, Mononuclear/immunology
  5. New advances and potentials of fungal immunomodulatory proteins for therapeutic purposes
    Ejike UC, Chan CJ, Okechukwu PN, Lim RLH
    Crit Rev Biotechnol, 2020 Dec;40(8):1172-1190.
    PMID: 32854547 DOI: 10.1080/07388551.2020.1808581
    Fungal immunomodulatory proteins (FIPs) are fascinating small and heat-stable bioactive proteins in a distinct protein family due to similarities in their structures and sequences. They are found in fungi, including the fruiting bodies producing fungi comprised of culinary and medicinal mushrooms. Structurally, most FIPs exist as homodimers; each subunit consisting of an N-terminal α-helix dimerization and a C-terminal fibronectin III domain. Increasing numbers of identified FIPs from either different or same fungal species clearly indicates the growing research interests into its medicinal properties which include immunomodulatory, anti-inflammation, anti-allergy, and anticancer. Most FIPs increased IFN-γ production in peripheral blood mononuclear cells, potentially exerting immunomodulatory and anti-inflammatory effects by inhibiting overproduction of T helper-2 (Th2) cytokines common in an allergy reaction. Recently, FIP from Ganoderma microsporum (FIP-gmi) was shown to promote neurite outgrowth for potential therapeutic applications in neuro-disorders. This review discussed FIPs' structural and protein characteristics, their recombinant protein production for functional studies, and the recent advances in their development and applications as pharmaceutics and functional foods.
    Matched MeSH terms: Leukocytes, Mononuclear/metabolism
  6. Construction of Naive and Immune Human Fab Phage-Display Library
    Omar N, Lim TS
    Methods Mol Biol, 2018;1701:25-44.
    PMID: 29116498 DOI: 10.1007/978-1-4939-7447-4_2
    This protocol describes the processes involved in the generation of human antibody libraries in Fab format. The antibody repertoire is derived from peripheral blood mononucleocytes focusing on different immunoglobulin isotypes. A two-step cloning process was used to generate a diverse human Fab library for subsequent selection by phage display. The method can be applied for the generation of both naive and immune antibody libraries. The naive repertoire allows for the library to be applied for the generation of human monoclonal antibodies against a broad range of target antigens making it a useful resource for antibody generation. However, the immune repertoire will be focused against target antigens from a particular disease. The protocol will focus on the generation of the library including the panning process.
    Matched MeSH terms: Leukocytes, Mononuclear/immunology*
  7. Construction of Naïve and Immune Human Fab Phage Display Library
    Lai JY, Lim TS
    Methods Mol Biol, 2023;2702:39-58.
    PMID: 37679614 DOI: 10.1007/978-1-0716-3381-6_3
    Phage display has been applied successfully for the rapid isolation of monoclonal antibodies against various targets including infectious diseases, autoantigens, cancer markers, and even small molecules. The main component in any phage display experiment is the availability of an antibody library to carry out the selection process of target-specific antibodies through an iterative process termed as biopanning. To generate human antibody libraries, the antibody repertoire can be obtained from human peripheral blood mononuclear cell (PBMC) or directly from cell-sorted B-cell populations. The choice of antibody isotype is dictated by the nature of the library. Naïve libraries would utilize IgM repertoires, whereas the IgG repertoire is commonly used for immune libraries. Antibody genes are amplified through polymerase chain reaction (PCR) and paired in a combinatorial fashion to expand the diversity of the cloned library repertoire. The protocol here describes the use of a two-step cloning method that can be applied for the construction of either a naïve or immune human antibody library in Fab format followed by the subsequent panning.
    Matched MeSH terms: Leukocytes, Mononuclear*
  8. Generation of a Naïve Human scFv Phage Display Library and Panning Selection
    Song BPC, Lai JY, Lim TS
    Methods Mol Biol, 2024;2793:21-40.
    PMID: 38526721 DOI: 10.1007/978-1-0716-3798-2_2
    Phage display antibody libraries have been successfully used as the essential tool to produce monoclonal antibodies against a plethora of targets ranging from diseases to native biologically important proteins as well as small molecules. It is well documented that diverse antibody genes are the major genetic source for the construction of a high-quality antibody library and selection of high-affinity antibodies. Naïve antibody libraries are derived using the IgM repertoire of healthy donors obtained from B-cells isolated from human peripheral blood mononuclear cell (PBMC). Single-chain fragment variable (scFv) is a routinely used format due to its smaller size and preference for phage display. The process involves the use of a two-step cloning method for library construction. The protocol also covers the biopanning process for target positive clone selection.
    Matched MeSH terms: Leukocytes, Mononuclear
  9. Fulltext Plasma and cell lysate proteins associated with treatment outcome in acute myeloid leukaemia
    Fatemeh Barantalab, Pei-Pei Chong, Cindee Lee, Stephnie Kang Xian Yiau, Kian Meng Chang, Zainina Seman, et al.
    Malaysian Journal of Medicine and Health Sciences, 2020;16(2):23-29.
    MyJurnal
    Introduction: Drug-resistance is a major hindrance to successful treatment of AML. Current predictive biomarkers are mainly genetic aberrations and insufficient in foretelling treatment outcome in all acute myeloid leukaemia (AML) due to its heterogeneous and aggressive nature. Proteins are stable and reliable. Secreted proteins in AML may have predictive or prognostic values for early intervention. Proteomic studies on AML are few and further investigations will benefit in selection of best markers. The aim of the study was to identify differentially expressed plasma proteins in AML with different treatment outcome. Methods: Two-dimensional electrophoresis (2-DE) technique was utilised to identify proteins differentially expressed in chemo-sensitive/chemo-resistant AML. Plasma and peripheral blood mononuclear cell (PBMC) lysate proteome analysis were performed on six chemo-resistant, four chemo-sensitive and six healthy controls and seven chemo-resistant, three chemo-sensitive and six healthy controls, respectively. Each experiment was conducted in duplicate or triplicate. Images were captured and protein spots detected by software. Differentially expressed protein spots were excised from gel and proteins were identified using LC/MS/MS. Proteins spots that were also detected in healthy controls were excluded. Results: Comparing mean % volume of each spot demonstrated significantly enhanced expression of apoliprotein-E (APO-E) and haptoglobin (HP) (p
    Matched MeSH terms: Leukocytes, Mononuclear
  10. Fulltext Differential expression patterns of leukaemia associated genes in leukaemia cell lines compared to healthy controls
    Ang Pei-Shen, Rajesh Ramasamy, Noor Hamidah Hussin, Cheong Soon-Keng, Seow Heng-Fong, Maha Abdullah
    Malaysian Journal of Medicine and Health Sciences, 2016;12(1):0-0.
    MyJurnal
    Introduction: The phenotype and genotype of cancer cells portray hallmarks of cancer which may
    have clinical value. Cancer cell lines are ideal models to study and confirm these characteristics. We
    previously established two subtracted cDNA libraries with differentially expressed genes from an
    acute myeloid leukaemia patient with poor prognosis (PP) and good prognosis (GP). Objective: To
    compare gene expression of the leukaemia associated genes with selected biological characteristics
    in leukaemia cell lines and normal controls. Methodology: Expression of 28 PP genes associated
    with early fetal/embryonic development, HOX-related genes, hematopoiesis and aerobic glycolysis/
    hypoxia genes and 36 GP genes involved in oxidative phosphorylation, protein synthesis, chromatin
    remodelling and cell motility were examined in B-lymphoid (BV173, Reh and RS4;11) and myeloid
    (HL-60, K562) leukaemia cell lines after 72h in culture as well as peripheral blood mononuclear cells
    from healthy controls (N=5) using semi-quantitative polymerase chain reaction (PCR) method. Cell
    cycle profiles were analysed on flow cytometry while MTT cytotoxicity assay was used to determine
    drug resistance to epirubicin. Results: Genes expressed significantly higher in B-lymphoid leukaemia
    cell lines compared to healthy controls were mostly of the GP library i.e. oxidative phosphorylation
    (3/10), protein synthesis (4/11), chromatin remodelling (3/3) and actin cytoskeleton genes (1/5). Only
    two genes with significant difference were from the PP library. Cancer associated genes, HSPA9 and
    PSPH (GP library) and BCAP31 (PP library) were significantly higher in the B-lymphoid leukemia cell
    lines. No significant difference was observed between myeloid cell lines and healthy controls. This
    may also be due heterogeneity of cell lines studied. PBMC from healthy controls were not in cell cycle.
    G2/M profiles and growth curves showed B-lymphoid cells just reaching plateau after 72 hour culture
    while myeloid cells were declining. IC50 values from cytotoxicity assay revealed myeloid cell lines had
    an average 13-fold higher drug resistance to epirubicin compared to B-lymphoid cell lines. Only CCL1,
    was expressed at least two-fold higher in myeloid compared to B-lymphoid cell lines. In contrast,
    MTRNR2, EEF1A1, PTMA, HLA-DR, C6orf115, PBX3, ENPP4, SELL, and IL3Ra were expressed
    more than 2-fold higher in B-lymphoid compared to myeloid cell lines studied here. Conclusion: Thus,
    B-lymphoid leukaemia cell lines here exhibited active, proliferating characteristics closer to GP genes.
    Higher expression of several genes in B-lymphoid compared to myeloid leukaemia cell lines may be
    useful markers to study biological differences including drug resistance between lineages.
    Matched MeSH terms: Leukocytes, Mononuclear
  11. Fulltext Targeted disruption of pi-pi stacking in Malaysian banana lectin reduces mitogenicity while preserving antiviral activity
    Covés-Datson EM, King SR, Legendre M, Swanson MD, Gupta A, Claes S, et al.
    Sci Rep, 2021 01 12;11(1):656.
    PMID: 33436903 DOI: 10.1038/s41598-020-80577-7
    Lectins, carbohydrate-binding proteins, have been regarded as potential antiviral agents, as some can bind glycans on viral surface glycoproteins and inactivate their functions. However, clinical development of lectins has been stalled by the mitogenicity of many of these proteins, which is the ability to stimulate deleterious proliferation, especially of immune cells. We previously demonstrated that the mitogenic and antiviral activities of a lectin (banana lectin, BanLec) can be separated via a single amino acid mutation, histidine to threonine at position 84 (H84T), within the third Greek key. The resulting lectin, H84T BanLec, is virtually non-mitogenic but retains antiviral activity. Decreased mitogenicity was associated with disruption of pi-pi stacking between two aromatic amino acids. To examine whether we could provide further proof-of-principle of the ability to separate these two distinct lectin functions, we identified another lectin, Malaysian banana lectin (Malay BanLec), with similar structural features as BanLec, including pi-pi stacking, but with only 63% amino acid identity, and showed that it is both mitogenic and potently antiviral. We then engineered an F84T mutation expected to disrupt pi-pi stacking, analogous to H84T. As predicted, F84T Malay BanLec (F84T) was less mitogenic than wild type. However, F84T maintained strong antiviral activity and inhibited replication of HIV, Ebola, and other viruses. The F84T mutation disrupted pi-pi stacking without disrupting the overall lectin structure. These findings show that pi-pi stacking in the third Greek key is a conserved mitogenic motif in these two jacalin-related lectins BanLec and Malay BanLec, and further highlight the potential to rationally engineer antiviral lectins for therapeutic purposes.
    Matched MeSH terms: Leukocytes, Mononuclear/drug effects*; Leukocytes, Mononuclear/virology
  12. Immunomodulatory effects of damnacanthal isolated from roots of Morinda elliptica
    Alitheen NB, Manaf AA, Yeap SK, Shuhaimi M, Nordin L, Mashitoh AR
    Pharm Biol, 2010 Apr;48(4):446-52.
    PMID: 20645725 DOI: 10.3109/13880200903168031
    Morinda elliptica Ridley (Rubiaceae) has been used traditionally as a medicine to treat various diseases in Malaysia and southeast Asia. In the present study we investigated the immunomodulatory effects of damnacanthal isolated from the roots of Morinda elliptica. The immunomodulatory effect of this compound was evaluated by using the lymphocyte proliferation assay with mouse thymocytes and human peripheral blood mononuclear cells (PBMC). In addition, the effect of the compound on PBMC cell cycle progression was studied by using flow cytometry. The production of human interleukin-2 and human inteleukin-12 cytokines was also assessed using the enzyme linked immunosorbent assay (ELISA) technique. The lymphocyte proliferation assay showed that damnacanthal was able to activate mouse thymocytes and PBMC at a low concentration (0.468 microg/mL). Moreover, the production of human interleukin-2 and human interleukin-12 cytokines in the culture supernatant from damnacanthal activated lymphocytes was markedly up-regulated at 24 h and sustained until 72 h with a slight decrease with time. A positive correlation was found between the level of these two cytokines and the MTT-based proliferation assay. Based on the above results, damnacanthal can act as an immunomodulatory agent which may be very useful for maintaining a healthy immune system.
    Matched MeSH terms: Leukocytes, Mononuclear/drug effects; Leukocytes, Mononuclear/immunology
  13. 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
  14. Catharanthus roseus Aqueous Extract is Cytotoxic to Jurkat Leukaemic T-cells but Induces the Proliferation of Normal Peripheral Blood Mononuclear Cells
    Ahmad NH, Rahim RA, Mat I
    Trop Life Sci Res, 2010 Dec;21(2):101-13.
    PMID: 24575203
    Research on natural products has been widely used as a strategy to discover new drugs with potential for applications in complementary medicines because they have fewer side effects than conventional drugs. The aim of the present study was to evaluate the in vitro cytotoxic effects of crude aqueous Catharanthus roseus extract on Jurkat cells and normal peripheral blood mononuclear cells (PBMCs). The aqueous extract was standardised to vinblastine by high performance liquid chromatography (HPLC) and was used to determine cytotoxicity by the MTS [3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay. DNA fragmentation assay was employed to determine if cell death was due to apoptosis. The results showed that the aqueous extract induced cell death of Jurkat cells at 24, 48 and 72 hours post-treatment in a time- and dose-dependent manner. However, cells treated at 48 and 72 hours produced higher cytotoxic effects with half maximal inhibitory concentration (IC50) values of 2.55 μg/ml and 2.38 μg/ml, respectively. In contrast, the extract induced normal PBMC proliferation, especially after 24 hours treatment with 1000 μg/ml. This result indicates that the C. roseus crude aqueous extract showed differential effects of inhibiting the proliferation of the Jurkat cell line and promoting the growth of PBMCs. These data suggest that the extract may be applicable for modulating the normal and transformed immune cells in leukaemia patients.
    Matched MeSH terms: Leukocytes, Mononuclear
  15. Fulltext Transcriptome landscape of human primary monocytes at different sequencing depth
    Mirsafian H, Ripen AM, Leong WM, Manaharan T, Mohamad SB, Merican AF
    Genomics, 2017 Oct;109(5-6):463-470.
    PMID: 28733102 DOI: 10.1016/j.ygeno.2017.07.003
    Differential gene and transcript expression pattern of human primary monocytes from healthy young subjects were profiled under different sequencing depths (50M, 100M, and 200M reads). The raw data consisted of 1.3 billion reads generated from RNA sequencing (RNA-Seq) experiments. A total of 17,657 genes and 75,392 transcripts were obtained at sequencing depth of 200M. Total splice junction reads showed an even more significant increase. Comparative analysis of the expression patterns of immune-related genes revealed a total of 217 differentially expressed (DE) protein-coding genes and 50 DE novel transcripts, in which 40 DE protein-coding genes were related to the immune system. At higher sequencing depth, more genes, known and novel transcripts were identified and larger proportion of reads were allowed to map across splice junctions. The results also showed that increase in sequencing depth has no effect on the sequence alignment.
    Matched MeSH terms: Leukocytes, Mononuclear/chemistry*
  16. Fulltext Computational, crystallographic studies, cytotoxicity and anti-tubercular activity of substituted 7-methoxy-indolizine analogues
    Venugopala KN, Chandrashekharappa S, Pillay M, Abdallah HH, Mahomoodally FM, Bhandary S, et al.
    PLoS One, 2019;14(6):e0217270.
    PMID: 31163040 DOI: 10.1371/journal.pone.0217270
    Indolizines are heteroaromatic compounds, and their synthetic analogues have reportedly showed promising pharmacological properties. In this study, a series of synthetic 7-methoxy-indolizine derivatives were synthesised, characterised and evaluated for in vitro whole-cell anti-tuberculosis (TB) screening against susceptible (H37Rv) and multi-drug-resistant (MDR) strains of Mycobacterium tuberculosis (MTB) using the resazurin microplate assay method. The cytotoxicity was evaluated using the MTT assay. In silico molecular-docking study was conducted for compounds 5a-j against enoyl-[acyl-carrier] protein reductase, a key enzyme of the type II fatty acid synthesis that has attracted much interest for the development of novel anti-TB compounds. Thereafter, molecular dynamic (MD) simulation was undertaken for the most active inhibitors. Compounds 5i and 5j with the methoxy functional group at the meta position of the benzoyl group, which was at the third position of the indolizine nucleus, demonstrated encouraging anti-TB activity against MDR strains of MTB at 16 μg/mL. In silico studies showed binding affinity within the range of 7.07-8.57 kcal/mol, with 5i showing the highest binding affinity. Hydrogen bonding, π-π- interactions, and electrostatic interactions were common with the active site. Most of these interactions occurred with the catalytic amino acids (Pro193, Tyr158, Phe149, and Lys165). MD simulation showed that 5j possessed the highest binding affinity toward the enzyme, according to the two calculation methods (MM/PBSA and MM/GBSA). The single-crystal X-ray studies of compounds 5c and 5d revealed that the molecular arrangements in these two structures were mostly guided by C-H···O hydrogen-bonded dimeric motifs and C-H···N hydrogen bonds, while various secondary interactions (such as π···π and C-H···F) also contributed to crystal formation. Compounds 5a, 5c, 5i, and 5j exhibited no toxicity up to 500 μg/mL. In conclusion, 5i and 5j are promising anti-TB compounds that have shown high affinity based on docking and MD simulation results.
    Matched MeSH terms: Leukocytes, Mononuclear/metabolism
  17. 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
  18. Increased Proinflammatory Cytokine Production by Chronic Hepatitis B Patients with Mutant Hepatitis B Virus: Plausible Mechanisms Underlying Severe Liver Diseases in These Patients
    Raihan R, Akbar SMF, Al Mahtab M, Khan MSI, Tabassum S, Tee KK, et al.
    Viral Immunol, 2020 09;33(7):530-534.
    PMID: 32513066 DOI: 10.1089/vim.2019.0198
    Hepatitis B virus (HBV) is a noncytopathic virus and billions of HBV-infected patients live uneventful lives and do not suffer from notable liver damage. However, HBV also causes progressive liver diseases characterized by hepatic inflammation, hepatic fibrosis, and liver cancer in millions of HBV-infected patients. The goal of this study was to evaluate the role of mutant HBV in HBV pathogenesis. In a cohort of 360 chronic HBV-infected patients, mutations at T1762/A1764 of HBV genome were detected in most of the patients with HBV-induced liver cirrhosis and hepatocellular carcinoma. To explore if mutations at T1762/A1764 of HBV genome has any role in progressive liver disease, peripheral blood mononuclear cells (PBMCs) and antigen-presenting dendritic cells (DCs) were isolated from five chronic hepatitis B (CHB) patients with mutations at T1762/A1764 and five comparable patients of CHB without mutations at T1762/A1764. DCs were pulsed with hepatitis B surface antigen (HBsAg). The levels of cytokines produced by PBMCs and DCs as well as nitrite production by DCs were evaluated. Significantly higher levels of interleukin-12, tumor necrosis factor-alpha, interferon-gamma, and transforming growth factor-beta were detected in cultures of PBMCs, DCs, and HBsAg-pulsed DCs from CHB patients with mutations at T1762/A1764 compared with those without mutations (p 
    Matched MeSH terms: Leukocytes, Mononuclear/immunology
  19. A profile of TNFR2+ regulatory T cells and CD103+ dendritic cells in the peripheral blood of patients with asthma
    Azid NA, Ahmad S, Boer JC, Al-Hatamleh MAI, Mohammad N, Mohd Ashari NS, et al.
    Hum Immunol, 2020 08 06;81(10-11):634-643.
    PMID: 32771274 DOI: 10.1016/j.humimm.2020.07.006
    The interaction of tolerogenic CD103+ dendritic cells (DCs) with regulatory T (Tregs) cells modulates immune responses by inducing immune tolerance. Hence, we determined the proportion of these cells in the peripheral blood mononuclear cells (PBMC) of asthmatic patients. We observed lower trends of CD11b-CD103+ DCs and CD86 within CD11b-CD103+ DCs, while increased levels of Foxp3 expressing CD25+/-TNFR2+ cells in asthmatics. There was a positive correlation in the expression of Foxp3 within CD3+CD4+CD25+TNFR2+ Tregs and CD11b-CD103+ as well as the expression of CD86 within HLA-DR+CD11c+CD11b-CD103+ DCs. In conclusion, we suggest that the increased levels of Tregs in blood could continuously suppress the T helper 2 (Th2) cells activation in the circulation which is also supported by the increase of anti-inflammatory cytokines IL-10 and TNF. Overall, functional immunoregulation of the regulatory cells, particularly Tregs, exhibit immune suppression and induce immune tolerance linked with the immune activation by the antigen presenting cells (APC).
    Matched MeSH terms: Leukocytes, Mononuclear
  20. 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
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