Displaying publications 1861 - 1880 of 3312 in total

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  1. Common Genetic Variation in Circadian Rhythm Genes and Risk of Epithelial Ovarian Cancer (EOC)
    Jim HS, Lin HY, Tyrer JP, Lawrenson K, Dennis J, Chornokur G, et al.
    J Genet Genome Res, 2015 09 15;2(2).
    PMID: 26807442
    Disruption in circadian gene expression, whether due to genetic variation or environmental factors (e.g., light at night, shiftwork), is associated with increased incidence of breast, prostate, gastrointestinal and hematologic cancers and gliomas. Circadian genes are highly expressed in the ovaries where they regulate ovulation; circadian disruption is associated with several ovarian cancer risk factors (e.g., endometriosis). However, no studies have examined variation in germline circadian genes as predictors of ovarian cancer risk and invasiveness. The goal of the current study was to examine single nucleotide polymorphisms (SNPs) in circadian genes BMAL1, CRY2, CSNK1E, NPAS2, PER3, REV1 and TIMELESS and downstream transcription factors KLF10 and SENP3 as predictors of risk of epithelial ovarian cancer (EOC) and histopathologic subtypes. The study included a test set of 3,761 EOC cases and 2,722 controls and a validation set of 44,308 samples including 18,174 (10,316 serous) cases and 26,134 controls from 43 studies participating in the Ovarian Cancer Association Consortium (OCAC). Analysis of genotype data from 36 genotyped SNPs and 4600 imputed SNPs indicated that the most significant association was rs117104877 in BMAL1 (OR = 0.79, 95% CI = 0.68-0.90, p = 5.59 × 10-4]. Functional analysis revealed a significant down regulation of BMAL1 expression following cMYC overexpression and increasing transformation in ovarian surface epithelial (OSE) cells as well as alternative splicing of BMAL1 exons in ovarian and granulosa cells. These results suggest that variation in circadian genes, and specifically BMAL1, may be associated with risk of ovarian cancer, likely through disruption of hormonal pathways.
    Matched MeSH terms: Granulosa Cells
  2. Metformin synergizes 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) combination therapy through impairing intracellular ATP production and DNA repair in breast cancer stem cells
    Soo JS, Ng CH, Tan SH, Malik RA, Teh YC, Tan BS, et al.
    Apoptosis, 2015 Oct;20(10):1373-87.
    PMID: 26276035 DOI: 10.1007/s10495-015-1158-5
    Metformin, an AMPK activator, has been reported to improve pathological response to chemotherapy in diabetic breast cancer patients. To date, its mechanism of action in cancer, especially in cancer stem cells (CSCs) have not been fully elucidated. In this study, we demonstrated that metformin, but not other AMPK activators (e.g. AICAR and A-769662), synergizes 5-fluouracil, epirubicin, and cyclophosphamide (FEC) combination chemotherapy in non-stem breast cancer cells and breast cancer stem cells. We show that this occurs through an AMPK-dependent mechanism in parental breast cancer cell lines. In contrast, the synergistic effects of metformin and FEC occurred in an AMPK-independent mechanism in breast CSCs. Further analyses revealed that metformin accelerated glucose consumption and lactate production more severely in the breast CSCs but the production of intracellular ATP was severely hampered, leading to a severe energy crisis and impairs the ability of CSCs to repair FEC-induced DNA damage. Indeed, addition of extracellular ATP completely abrogated the synergistic effects of metformin on FEC sensitivity in breast CSCs. In conclusion, our results suggest that metformin synergizes FEC sensitivity through distinct mechanism in parental breast cancer cell lines and CSCs, thus providing further evidence for the clinical relevance of metformin for the treatment of cancers.
    Matched MeSH terms: Neoplastic Stem Cells/drug effects*; Embryonic Stem Cells/metabolism
  3. Effects of Perivitelline Fluid Obtained from Horseshoe Crab on The Proliferation and Genotoxicity of Dental Pulp Stem Cells
    Musa M, Mohd Ali K, Kannan TP, Azlina A, Omar NS, Chatterji A, et al.
    Cell J, 2015;17(2):253-63.
    PMID: 26199904
    OBJECTIVE: Perivitelline fluid (PVF) of the horseshoe crab embryo has been reported to possess an important role during embryogenesis by promoting cell proliferation. This study aims to evaluate the effect of PVF on the proliferation, chromosome aberration (CA) and mutagenicity of the dental pulp stem cells (DPSCs).

    MATERIALS AND METHODS: This is an in vitro experimental study. PVF samples were collected from horseshoe crabs from beaches in Malaysia and the crude extract was prepared. DPSCs were treated with different concentrations of PVF crude extract in an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay (cytotoxicity test). We choose two inhibitory concentrations (IC50 and IC25) and two PVF concentrations which produced more cell viability compared to a negative control (100%) for further tests. Quantitative analysis of the proliferation activity of PVF was studied using the AlamarBlue®assay for 10 days. Population doubling times (PDTs) of the treatment groups were calculated from this assay. Genotoxicity was evaluated based on the CA and Ames tests. Statistical analysis was carried out using independent t test to calculate significant differences in the PDT and mitotic indices in the CA test between the treatment and negative control groups. Significant differences in the data were P<0.05.

    RESULTS: A total of four PVF concentrations retrieved from the MTT assay were 26.887 mg/ml (IC50), 14.093 mg/ml (IC25), 0.278 mg/ml (102% cell viability) and 0.019 mg/ml (102.5% cell viability). According to the AlamarBlue®assay, these PVF groups produced comparable proliferation activities compared to the negative (untreated) control. PDTs between PVF groups and the negative control were insignificantly different (P>0.05). No significant aberrations in chromosomes were observed in the PVF groups and the Ames test on the PVF showed the absence of significant positive results.

    CONCLUSION: PVF from horseshoe crabs produced insignificant proliferative activity on treated DPSCs. The PVF was non-genotoxic based on the CA and Ames tests.

    Matched MeSH terms: Stem Cells
  4. Cd(2+) Triggered the FRET "ON": A New Molecular Switch for the Ratiometric Detection of Cd(2+) with Live-Cell Imaging and Bound X-ray Structure
    Aich K, Goswami S, Das S, Mukhopadhyay CD, Quah CK, Fun HK
    Inorg Chem, 2015 Aug 3;54(15):7309-15.
    PMID: 26192906 DOI: 10.1021/acs.inorgchem.5b00784
    On the basis of the Förster resonance energy transfer mechanism between rhodamine and quinoline-benzothiazole conjugated dyad, a new colorimetric as well as fluorescence ratiometric probe was synthesized for the selective detection of Cd(2+). The complex formation of the probe with Cd(2+) was confirmed through Cd(2+)-bound single-crystal structure. Capability of the probe as imaging agent to detect the cellular uptake of Cd(2+) was demonstrated here using living RAW cells.
    Matched MeSH terms: RAW 264.7 Cells
  5. Anti-cancerous efficacy and pharmacokinetics of 6-mercaptopurine loaded chitosan nanoparticles
    Kumar GP, Sanganal JS, Phani AR, Manohara C, Tripathi SM, Raghavendra HL, et al.
    Pharmacol Res, 2015 Oct;100:47-57.
    PMID: 26232590 DOI: 10.1016/j.phrs.2015.07.025
    6-Mercaptopurine is a cytotoxic and immunosuppressant drug. The use of this drug is limited due to its poor bioavailability and short plasma half-life. In order to nullify these drawbacks, 6-mercaptopurine-chitosan nanoparticles (6-MP-CNPs) were prepared and evaluated to study the influence of preparation conditions on the physicochemical properties by using DLS, SEM, XRD and FTIR. The in vitro drug release profile at pH 4.8 and 7.4 revealed sustained release patterns for a period of 2 days. The nanoformulations showed enhanced in vitro anti-cancer activities (MTT assay, apoptosis assay, cell cycle arrest and ROS indices) on HT-1080 and MCF-7 cells. In vivo pharmacokinetics profiles of 6-MP-CNPs showed improved bioavailability. Thus, the results of the present study revealed that, the prepared 6-MP-CNPs have a significant role in increasing anti-cancer efficacy, bioavailability and in vivo pharmacokinetics profiles.
    Matched MeSH terms: MCF-7 Cells
  6. Fulltext Control of Polyamine Biosynthesis by Antizyme Inhibitor 1 Is Important for Transcriptional Regulation of Arginine Vasopressin in the Male Rat Hypothalamus
    Greenwood MP, Greenwood M, Paton JF, Murphy D
    Endocrinology, 2015 Aug;156(8):2905-17.
    PMID: 25961839 DOI: 10.1210/en.2015-1074
    The polyamines spermidine and spermine are small cations present in all living cells. In the brain, these cations are particularly abundant in the neurons of the paraventricular (PVN) and supraoptic nuclei (SON) of the hypothalamus, which synthesize the neuropeptide hormones arginine vasopressin (AVP) and oxytocin. We recently reported increased mRNA expression of antizyme inhibitor 1 (Azin1), an important regulator of polyamine synthesis, in rat SON and PVN as a consequence of 3 days of dehydration. Here we show that AZIN1 protein is highly expressed in both AVP- and oxytocin-positive magnocellular neurons of the SON and PVN together with antizyme 1 (AZ1), ornithine decarboxylase, and polyamines. Azin1 mRNA expression increased in the SON and PVN as a consequence of dehydration, salt loading, and acute hypertonic stress. In organotypic hypothalamic cultures, addition of the irreversible ornithine decarboxylase inhibitor DL-2-(difluoromethyl)-ornithine hydrochloride significantly increased the abundance of heteronuclear AVP but not heteronuclear oxytocin. To identify the function of Azin1 in vivo, lentiviral vectors that either overexpress or knock down Azin1 were stereotaxically delivered into the SON and/or PVN. Azin1 short hairpin RNA delivery resulted in decreased plasma osmolality and had a significant effect on food intake. The expression of AVP mRNA was also significantly increased in the SON by Azin1 short hairpin RNA. In contrast, Azin1 overexpression in the SON decreased AVP mRNA expression. We have therefore identified AZIN1, and hence by inference, polyamines as novel regulators of the expression of the AVP gene.
    Matched MeSH terms: Cells, Cultured
  7. Tocotrienol-rich fraction prevents cellular aging by modulating cell proliferation signaling pathways
    Khor SC, Mohd Yusof YA, Wan Ngah WZ, Makpol S
    Clin Ter, 2015;166(2):e81-90.
    PMID: 25945449 DOI: 10.7417/CT.2015.1825
    BACKGROUND AND OBJECTIVE: Vitamin E has been suggested as nutritional intervention for the prevention of degenerative and age-related diseases. In this study, we aimed to elucidate the underlying mechanism of tocotrienol-rich fraction (TRF) in delaying cellular aging by targeting the proliferation signaling pathways in human diploid fibroblasts (HDFs).

    MATERIALS AND METHODS: Tocotrienol-rich fraction was used to treat different stages of cellular aging of primary human diploid fibroblasts viz. young (passage 6), pre-senescent (passage 15) and senescent (passage 30). Several selected targets involved in the downstream of PI3K/AKT and RAF/MEK/ERK pathways were compared in total RNA and protein.

    RESULTS: Different transcriptional profiles were observed in young, pre-senescent and senescent HDFs, in which cellular aging increased AKT, FOXO3, CDKN1A and RSK1 mRNA expression level, but decreased ELK1, FOS and SIRT1 mRNA expression level. With tocotrienol-rich fraction treatment, gene expression of AKT, FOXO3, ERK and RSK1 mRNA was decreased in senescent cells, but not in young cells. The three down-regulated mRNA in cellular aging, ELK1, FOS and SIRT1, were increased with tocotrienol-rich fraction treatment. Expression of FOXO3 and P21Cip1 proteins showed up-regulation in senescent cells but tocotrienol-rich fraction only decreased P21Cip1 protein expression in senescent cells.

    CONCLUSIONS: Tocotrienol-rich fraction exerts gene modulating properties that might be responsible in promoting cell cycle progression during cellular aging.

    Matched MeSH terms: Cells, Cultured
  8. Fulltext Suppression of Human T Cell Proliferation Mediated by the Cathepsin B Inhibitor, z-FA-FMK Is Due to Oxidative Stress
    Rajah T, Chow SC
    PLoS One, 2015;10(4):e0123711.
    PMID: 25915766 DOI: 10.1371/journal.pone.0123711
    The cathepsin B inhibitor, benzyloxycarbonyl-phenylalanine-alanine-fluoromethyl ketone (z-FA-FMK) readily inhibits anti-CD3-induced human T cell proliferation, whereas the analogue benzyloxycarbonyl-phenylalanine-alanine-diazomethyl ketone (z-FA-DMK) had no effect. In contrast, benzyloxycarbonyl-phenylalanine-alanine-chloromethyl ketone (z-FA-CMK) was toxic. The inhibition of T cell proliferation mediated by z-FA-FMK requires not only the FMK moiety, but also the benzyloxycarbonyl group at the N-terminal, suggesting some degree of specificity in z-FA-FMK-induced inhibition of primary T cell proliferation. We showed that z-FA-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-induced T cell proliferation mediated by z-FA-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. The inhibition of anti-CD3-induced up-regulation of CD25 and CD69 expression mediated by z-FA-FMK was also attenuated in the presence of exogenous GSH. Similar to cell proliferation, GSH, NAC and L-cysteine but not D-cysteine, completely restored the processing of caspase-8 and caspase-3 to their respective subunits in z-FA-FMK-treated activated T cells. Our collective results demonstrated that the inhibition of T cell activation and proliferation mediated by z-FA-FMK is due to oxidative stress via the depletion of GSH.
    Matched MeSH terms: Cells, Cultured
  9. Fulltext Nipah virus encephalitis outbreak in Malaysia
    Lam SK, Chua KB
    Clin Infect Dis, 2002 May 1;34 Suppl 2:S48-51.
    PMID: 11938496 DOI: 10.1086/338818
    Emerging infectious diseases involving zoonosis have become important global health problems. The 1998 outbreak of severe febrile encephalitis among pig farmers in Malaysia caused by a newly emergent paramyxovirus, Nipah virus, is a good example. This disease has the potential to spread to other countries through infected animals and can cause considerable economic loss. The clinical presentation includes segmental myoclonus, areflexia, hypertension, and tachycardia, and histologic evidence includes endothelial damage and vasculitis of the brain and other major organs. Magnetic resonance imaging has demonstrated the presence of discrete high-signal-intensity lesions disseminated throughout the brain. Nipah virus causes syncytial formation in Vero cells and is antigenically related to Hendra virus. The Island flying fox (Pteropus hypomelanus; the fruit bat) is a likely reservoir of this virus. The outbreak in Malaysia was controlled through the culling of >1 million pigs.
    Matched MeSH terms: Vero Cells
  10. An evaluation of accelerated Portland cement as a restorative material
    Abdullah D, Ford TR, Papaioannou S, Nicholson J, McDonald F
    Biomaterials, 2002 Oct;23(19):4001-10.
    PMID: 12162333
    Biocompatibility of two variants of accelerated Portland cement (APC) were investigated in vitro by observing the cytomorphology of SaOS-2 osteosarcoma cells in the presence of test materials and the effect of these materials on the expression of markers of bone remodelling. Glass ionomer cement (GIC), mineral trioxide aggregate (MTA) and unmodified Portland cement (RC) were used for comparison. A direct contact assay was undertaken in four samples of each test material, collected at 12, 24, 48 and 72 h. Cell morphology was observed using scanning electron microscopy (SEM) and scored. Culture media were collected for cytokine quantification using enzyme-linked immunosorbent assay (ELISA). On SEM evaluation, healthy SaOS-2 cells were found adhering onto the surfaces of APC variant, RC and MTA. In contrast, rounded and dying cells were observed on GIC. Using ELISA, levels of interleukin (IL)-1beta, IL-6, IL-18 and OC were significantly higher in APC variants compared with controls and GIC (p<0.01), but these levels of cytokines were not statistically significant compared with MTA. The results of this study provide evidence that both APC variants are non-toxic and may have potential to promote bone healing. Further development of APC is indicated to produce a viable dental restorative material and possibly a material for orthopaedic
    Matched MeSH terms: Tumor Cells, Cultured
  11. Anti-tumour promoter activity in Malaysian ginger rhizobia used in traditional medicine
    Vimala S, Norhanom AW, Yadav M
    Br. J. Cancer, 1999 Apr;80(1-2):110-6.
    PMID: 10389986
    Zingiberaceae rhizomes commonly used in the Malaysian traditional medicine were screened for anti-tumour promoter activity using the short-term assay of inhibition of 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced Epstein-Barr virus early antigen (EBV-EA) in Raji cells. The inhibition of TPA-induced EBV-EA was detected using the indirect immunofluorescence assay (IFA) and Western blot technique. The indirect IFA detected the expression/inhibition of EBV-EA-D (diffused EA antigen), whereas the Western blot technique detected the expression/inhibition of both EBV-EA-D and EA-R (restricted EA antigen). Seven rhizomes were found to possess inhibitory activity towards EBV activation, induced by TPA; they are: Curcuma domestica, C. xanthorrhiza, Kaempferia galanga, Zingiber cassumunar, Z. officinale, Z. officinale (red variety), and Z. zerumbet. A cytotoxicity assay was carried out to determine the toxicity of the Zingiberaceae rhizome extracts. The rhizome extracts that exhibited EBV activation inhibitory activity had no cytotoxicity effect in Raji cells. Therefore, the present study shows that several Zingiberaceae species used in Malaysian traditional medicine contain naturally occurring non-toxic compounds that inhibit the EBV activation, which, if further investigated, could contribute in the development of cancer prevention methods at the tumour-promoting stage.
    Matched MeSH terms: Tumor Cells, Cultured
  12. Loss of mitochondrial transmembrane potential and caspase-9 activation during apoptosis induced by the novel styryl-lactone goniothalamin in HL-60 leukemia cells
    Inayat-Hussain SH, Annuar BO, Din LB, Ali AM, Ross D
    Toxicol In Vitro, 2003 Aug;17(4):433-9.
    PMID: 12849726
    Styryl-lactones such as goniothalamin represent a new class of compounds with potential anti-cancer properties. In this study, we investigated the mechanisms of goniothalamin (GTN), a plant styryl-lactone induced apoptosis in human promyelocytic leukemia HL-60 cells. This plant extract resulted in apoptosis in HL-60 cells as assessed by the externalisation of phosphatidylserine. Using the mitochondrial membrane dye (DIOC(6)) in conjunction with flow cytometry, we found that GTN treated HL-60 cells demonstrated a loss of mitochondrial transmembrane potential (Deltapsi(m)). Further immunoblotting on these cells showed activation of initiator caspase-9 and the executioner caspases-3 and -7. Pretreatment with the pharmacological caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp fluoromethyl ketone (Z-VAD.FMK) abrogated apoptosis as assessed by all of the apoptotic features in this study. In summary, our results demonstrate that goniothalamin-induced apoptosis occurs via the mitochondrial pathway in a caspase dependent manner.
    Matched MeSH terms: HL-60 Cells
  13. Cytotoxic prenylated depsidones from Garcinia parvifolia
    Xu YJ, Chiang PY, Lai YH, Vittal JJ, Wu XH, Tan BK, et al.
    J Nat Prod, 2000 Oct;63(10):1361-3.
    PMID: 11076552
    Leaf extracts of Garcinia parvifolia provided relatively high yields of four novel, cytotoxic prenylated depsidones. The structures were determined mainly by detailed NMR spectral analysis and X-ray crystallography.
    Matched MeSH terms: Tumor Cells, Cultured
  14. Antineoplastic agents. Part 409: Isolation and structure of montanastatin from a terrestrial actinomycete
    Pettit GR, Tan R, Melody N, Kielty JM, Pettit RK, Herald DL, et al.
    Bioorg Med Chem, 1999 May;7(5):895-9.
    PMID: 10400343
    A Montana soil actinomycete, Streptomyces anulatus, produced (1 x 10(-2)% yield) a new cancer cell growth inhibitory cyclooctadepsipeptide named montanastatin (1) accompanied by the potent anticancer antibiotic valinomycin (2) in very high (5.1%) yields. Valinomycin but not montanastatin inhibited growth of a number of pathogenic bacteria and fungi. Interpretation of high-field (500 MHz) NMR and high-resolution FAB mass spectral data allowed assignment of the structure cyclo-(D-Val-L-Lac-L-Val-D-Hiv) to montanastatin. Valinomycin (2) was also isolated from actinomycetes cultured from a tree branch and animal feces collected in Malaysia. Streptomyces exfoliatus, isolated from the tree branch, was found to contain valinomycin in 1.6% yield, while the fecal isolate, S. anulatus, gave valinomycin in 0.9% yield.
    Matched MeSH terms: Tumor Cells, Cultured
  15. Development of a modified method for sequencing high G:C regions in chicken anemia virus genome
    Chowdhury SM, Omar AR, Aini I, Hair-Bejo M, Jamaluddin AA, Wan KL, et al.
    J. Biochem. Mol. Biol. Biophys., 2002 Jun;6(3):229-32.
    PMID: 12186760
    Two areas in the chicken anemia virus (CAV) genome have high G:C content with secondary structures. These two G:C rich areas could not be sequenced with Perkin Elmer's Big Dye Terminator Cycle Sequencing Kit. Several modifications were carried out to solve the problem. Finally, a package of modified method was developed to sequence the high G:C areas. The result showed that the Perkin Elmer's Big Dye Terminator Cycle Sequencing Kit with the normal procedures are not suitable for sequencing the high G:C regions of the CAV genome. The present developed method made the Perkin Elmer's Kit useful for the first time to sequence the G:C rich hairpin structures of the CAV genome. The system may be useful to sequence all other G:C rich DNA templates.
    Matched MeSH terms: Tumor Cells, Cultured
  16. Altholactone, a novel styryl-lactone induces apoptosis via oxidative stress in human HL-60 leukemia cells
    Inayat-Hussain SH, Osman AB, Din LB, Taniguchi N
    Toxicol Lett, 2002 May 28;131(3):153-9.
    PMID: 11992734
    Plant styryl-lactone derivatives isolated from Goniothalamus sp. are potential compounds for cancer chemotherapy. In this study, we have examined the mechanisms of apoptosis induced by altholactone, a stryl-lactone isolated from the Malaysian plant G. malayanus on human HL-60 promyelocytic leukemia cells. Flow cytometric analysis of the externalization of phosphatidylserine (PS) using the annexin V/PI method on altholactone treated HL-60 cells showed a concentration-dependent increase of apoptosis from concentrations ranging from 10.8 (2.5 microg/ml) to 172.4 microM (40 microg/ml). Pre-treatment with the antioxidant N-acetylcysteine (1 mM) completely abrogated apoptosis induced by altholactone, suggesting for the involvement of oxidative stress. Further flow cytometric assessment of the level of intracellular peroxides using the fluorescent probe 2',7'-dichlorofluorescein diacetate (DCFH-DA) confirmed that altholactone induced an increase in cellular oxidative stress in HL-60 cells which was suppressed by N-acetylcysteine. In summary, our results demonstrate for the first time that altholactone induced apoptosis in HL-60 cells occurs via oxidative stress.
    Matched MeSH terms: HL-60 Cells
  17. Flavonone and chalcone derivatives from Cryptocarya kurzii
    Fu X, Sévenet T, Remy F, Païs M, Hamid A, Hadi A, et al.
    J Nat Prod, 1993 Jul;56(7):1153-63.
    PMID: 8377019
    Four complex flavanones, kurziflavolactones A [2], B [3], C [4], and D [5] and a complex chalcone 6 with an unprecedented carbon side chain on the flavanone or chalcone A ring have been isolated from a Malaysian plant, Cryptocarya kurzii (Lauraceae). Their structures were determined by extensive spectroscopic analysis, especially 2D nmr experiments. Compounds 3 and 6 showed slight cytotoxicity against KB cells, with IC50 values of 4 and 15 micrograms/ml, respectively. A biosynthetic pathway for the formation of these compounds is suggested.
    Matched MeSH terms: KB Cells
  18. Lectin extracts of champedak seeds demonstrate selective stimulation of T lymphocyte proliferation
    Hashim OH, Gendeh GS, Jaafar MI
    Biochem. Int., 1992 Jun;27(1):139-43.
    PMID: 1627170
    The effect of extracts of champedak (Artocarpus integer) seed lectin on the proliferation of normal human lymphocyte was investigated. The IgA1 binding lectin was demonstrated to stimulate the proliferation of human peripheral blood mononuclear cells. Action of the lectin on enriched T and B cell populations demonstrated T lymphocyte specificity. The lectin was not mitogenic to B lymphocytes. Optimal stimulation of proliferative response was achieved when cells were subjected to 5 days exposure to the crude lectin at 20 micrograms/ml.
    Matched MeSH terms: Cells, Cultured
  19. Comparison of three forms of antigens in the demonstration of cell-mediated immune response in murine toxoplasmosis
    Rahmah N, Khairul Anuar A
    Biochem Biophys Res Commun, 1992 Dec 15;189(2):640-4.
    PMID: 1472034
    Mice were chronically infected with cysts of ME49 strain of Toxoplasma gondii. At different periods post-infection, their spleens were removed and single cell suspensions were made. Lymphocyte transformation experiments were performed on the lymphocyte suspensions using three different kinds of antigens of ME49 strain of T. gondii, namely soluble, excretory/secretory and cystic forms. The results showed that the pattern of lymphocyte responsiveness was dependent on the kind of antigen employed for induction of the blastogenesis. Using soluble and cystic forms of the antigen, different periods of lymphocyte suppression and lymphocyte proliferation were demonstrated. However, with the use of excretory/secretory antigen, no significant suppression of lymphocyte stimulation was noted throughout the course of infection. Thus excretory/secretory antigen may be the best form of antigen for stimulation of the cell-mediated immune response and hence it appears to be a good candidate for vaccine in toxoplasmosis.
    Matched MeSH terms: Cells, Cultured
  20. Clonal diversity in single isolates of Malaysian Plasmodium falciparum
    Ang HH, Chan KL, Mak JW
    Med Trop (Mars), 1996;56(4):349-51.
    PMID: 9112620
    Six clones were derived from each of five isolates of Malaysian Plasmodium falciparum and characterized with regard to susceptibility to schizontocidal drugs, chloroquine, mefloquine, and quinine. The 5 isolates were found to be resistant to chloroquine and sensitive to mefloquine and quinine. Most of the clones displayed susceptibility patterns similar to those of their parent isolate, except ST9/D8 clone which became sensitive to chloroquine, C/C10 and ST148/A5 clones which became resistant to mefloquine and to quinine respectively. This diversity in susceptibility to schizontocidal drugs would likely have been overlooked by assessment of natural uncloned isolates against antimalarial drugs.
    Matched MeSH terms: Clone Cells
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