Displaying publications 1881 - 1900 of 3312 in total

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  1. Effect of tocotrienols on the growth of a human breast cancer cell line in culture
    Nesaretnam K, Guthrie N, Chambers AF, Carroll KK
    Lipids, 1995 Dec;30(12):1139-43.
    PMID: 8614304
    The tocotrienol-rich fraction (TRF) of palm oil consists of tocotrienols and some alpha-tocopherol (alpha-T). Tocotrienols are a form of vitamin E having an unsaturated side-chain, rather than the saturated side-chain of the more common tocopherols. Because palm oil has been shown not to promote chemically-induced mammary carcinogenesis, we tested effects of TRF and alpha-T on the proliferation, growth, and plating efficiency (PE) of the MDA-MB-435 estrogen-receptor-negative human breast cancer cells. TRF inhibited the proliferation of these cells with a concentration required to inhibit cell proliferation by 50% of 180 microgram/mL whereas alpha-T had no effect at concentrations up to 1000 microgram/mL as measured by incorporation of [3H]thymidine. The effects of TRF and alpha-T also were tested in longer-term growth experiments, using concentrations of 180 and 500 microgram/mL. We found that TRF inhibited the growth of these cells by 50%, whereas alpha-T did not. Their effect on the ability of these cells to form colonies also was studied, and it was found that TRF inhibited PE, whereas alpha T had no effect. These results suggest that the inhibition is due to the presence of tocotrienols in TRF rather than alpha T.
    Matched MeSH terms: Tumor Cells, Cultured
  2. Fulltext Antibody responses of dengue fever patients to dengue 2 (New Guinea C strain) viral proteins
    AbuBakar S, Azmi A, Mohamed-Saad N, Shafee N, Chee HY
    Malays J Pathol, 1997 Jun;19(1):41-51.
    PMID: 10879241
    The present study was undertaken to investigate the antibody responses of dengue fever (DF) patients to specific dengue virus proteins. Partially purified dengue 2 New Guinea C (NGC) strain virus was used as antigen. Under the present experimental protocols, it was observed that almost all DF patients' sera had detectable presence of antibodies which recognize the dengue 2 envelope (E) protein. The convalescent-phase sera especially had significant detectable IgG, IgM and IgE against the protein. In addition, IgGs specific against the NS1 dimer and PrM were also detected. Antibody against the core (C) protein, however, was not detectable in any of the DF patients' sera. The substantial presence of IgG against the PrM in the convalescent-phase sera, and the presence of IgE specific for the E, reflect the potential importance of these antibody responses in the pathogenesis of dengue.
    Matched MeSH terms: Cells, Cultured
  3. In vitro response of human breast cancer cell lines to the growth-inhibitory effects of styrylpyrone derivative (SPD) and assessment of its antiestrogenicity
    Hawariah A, Stanslas J
    Anticancer Res, 1998 Nov-Dec;18(6A):4383-6.
    PMID: 9891496
    Previous studies have shown that a styrylpyrone derivative (SPD) from a local tropical plant had antiprogestin and antiestrogenic effects in early pregnant mice models (Azimahtol et al. 1991). Antiprogestins and antiestrogens can be exploited as a therapeutic approach to breast cancer treatment and thus the antitumor activity of SPD was tested in three different human breast cancer cell lines that is: MCF- 7, T47D and MDA-MB-231, employing, the antiproliferative assay of Lin and Hwang (1991) slightly modified. SPD (10(-10) - 10(-6) M) exhibited strong antiproliferative activity in estrogen and progestin-dependent MCF-7 cells (EC50 = 2.24 x 10(-7) M) and in hormone insensitive MDA-MB-231 (EC50 = 5.62 x 10(-7) M), but caused only partial inhibition of the estrogen- insensitive T47D cells (EC50 = 1.58 x 10(-6) M). However, tamoxifen showed strong inhibition of MCF-7 cells (EC50 = 1.41 x 10(-6) M) and to a lesser extent the T47D cells (EC50 = 2.5 x 10(-6) M) but did not affect the MDA-MB-231 cells. SPD at 1 microM exerted a beffer antiestrogenic activity than 1 microM tamoxifen in suppressing the growth of MCF-7 cells stimulated by 1 nM estradiol. Combined treatment of both SPD and tamoxifen at 1 microM showed additional inhibition on the growth of MCF-7 cells in culture. The antiproliferative properties of SPD are effective on both receptor positive and receptor negative mammary cancer cells, and thus appear to be neither dependent on cellular receptor status nor cellular hormone responses. This enhances in vivo approaches as tumors are heterogenous masses with varying receptor status.
    Matched MeSH terms: Tumor Cells, Cultured
  4. Direct nucleotide sequencing using total cellular RNA from dengue-virus-infected mosquito cells
    Kautner IM, Lam SK
    Res. Virol., 1992 May-Jun;143(3):193-7.
    PMID: 1355609
    In recent years, a large amount of nucleotide sequence data for dengue viruses has been published. Most of it was derived by sequencing cDNA synthesized from highly purified genomic viral RNA. This paper presents a simple and rapid method for the isolation of total RNA from mosquito cells infected with dengue viruses. This RNA can be used for direct nucleotide sequencing with specific primers without the need for further purification.
    Matched MeSH terms: Cells, Cultured
  5. Tumour promoter activity in Malaysian Euphorbiaceae
    Norhanom AW, Yadav M
    Br. J. Cancer, 1995 Apr;71(4):776-9.
    PMID: 7710943
    Herbal medication has been practised by the rural Malaysian Malays for a long time. However, the long-term side-effects have never been studied. In the present study, 48 species of Euphorbiaceae were screened for tumour-promoter activity by means of an in vitro assay using a human lymphoblastoid cell line harbouring the Epstein-Barr virus (EBV) genome. Twenty-seven per cent (13 out of 48) of the species tested were found to be positive, and in four species, namely Breynia coronata Hk.f, Codiaeum variegatum (L) Bl, Euphorbia atoto and Exocoecaria agallocha, EBV-inducing activity was observed when the plant extracts were tested at low concentrations of between 0.2 and 1.2 micrograms ml-1 in cell culture. This observation warrants attention from the regular users of these plants because regular use of plants with tumour-promoting activity could well be an aetiological factor for the promotion of tumours among rural Malaysian Malays.
    Matched MeSH terms: Tumor Cells, Cultured
  6. Glutathione S-transferase and gamma-glutamyl transpeptidase activities in cultured rat hepatocytes treated with tocotrienol and tocopherol
    Ong FB, Wan Ngah WZ, Shamaan NA, Md Top AG, Marzuki A, Khalid AK
    Comp Biochem Physiol C Comp Pharmacol Toxicol, 1993 Sep;106(1):237-40.
    PMID: 7903615
    1. The effect of tocotrienol and tocopherol on glutathione S-transferase (GST) and gamma-glutamyl transpeptidase (GGT) activities in cultured rat hepatocytes were investigated. 2. Tocotrienol and tocopherol significantly decreased GGT activities at 5 days in culture but tocotrienol also significantly decreased GGT activities at 1-2 days. 3. Tocotrienol and tocopherol treatment significantly decreased GST activities at 3 days compared to the control but tocotrienol also decreased GST activities at 1-3 days. 4. Tocotrienol showed a more pronounced effect at a dosage of greater than 50 microM tocotrienol at 1-3 days in culture compared to the control.
    Matched MeSH terms: Cells, Cultured
  7. Heat-killed Salmonella typhi induces the release of prostaglandins and leukotrienes from mouse macrophages
    Pang T, Devi S, Puthucheary S, Pawlowski N
    Microbiol. Immunol., 1991;35(3):267-71.
    PMID: 1870442
    Mouse macrophages pre-labeled with [3H]arachidonic acid (20:4) were shown to release metabolites generated by the lipoxygenase and cyclo-oxygenase pathways following in vitro addition of heat-killed Salmonella typhi. These metabolites were maximally released after 60-90 min of incubation and consisted of prostaglandins (85%), leukotriene C (6%), di-HETEs, leukotrienes D and E (4%), mono-HETEs (2%) and other metabolites (3%). Of the metabolites generated by the cyclo-oxygenase pathway (prostaglandins), 6-keto PGF1 alpha and PGE2 were generated at a ratio of 1.2 to 1. The significance and importance of these results are discussed.
    Matched MeSH terms: Cells, Cultured
  8. Inhibition of macromolecular synthesis in cultured macrophages by Pseudomonas pseudomallei exotoxin
    Mohamed R, Nathan S, Embi N, Razak N, Ismail G
    Microbiol. Immunol., 1989;33(10):811-20.
    PMID: 2615673
    Pseudomonas pseudomallei exotoxin was found to be a potent inhibitor of protein and DNA synthesis in cultured macrophages. Inhibition of DNA synthesis occurred at toxin concentrations as low as 1-2 micrograms/ml and inhibition of 3H-thymidine uptake was almost complete at concentrations of 8 micrograms/ml or more. A close correlation between cell damage and inhibition by DNA synthesis was observed. For protein synthesis, inhibition was obtained at much lower doses (0.06-2.0 micrograms/ml) of the toxin. At similar toxin concentrations, DNA synthesis was marginally affected. Further, it was shown that protein synthesis inhibition occurred almost immediately after incubation, reaching its maximal inhibitory effect of 70% after 6 hr. DNA synthesis, however, was minimally affected by a similar toxin concentration even after 10 hr of incubation. The inhibition of macromolecular synthesis in macrophages by P. pseudomallei exotoxin may be relevant to its modulatory effect on the host defense mechanism.
    Matched MeSH terms: Cells, Cultured
  9. Further serum related alterations in the activities of some membrane marker enzymes in normal and virus transformed cells
    Tenang EM, McCaldin B
    Biochem. Int., 1989 Jan;18(1):197-202.
    PMID: 2541720
    The activities of membrane marker enzymes in normal (3T3) and simian virus transformed mouse cells (SV3T3) are affected not only by densities of cultures but also by the sera types used in the growth media. We have assayed the levels of 5'nucleotidase, monoamine oxidase and rotenone insensitive NADH ferricyanide reductase in these cells grown to sparse and confluent cultures in medium supplemented with 10% newborn calf serum (n.c.s.) or in medium supplemented with 10% foetal bovine serum (f.b.s.). It was found that in 3T3 cells grown in 10% f.b.s. the transition from sparse to confluent cultures was associated with a reduction in the activities of the marker enzymes while in those grown in 10% n.c.s., the activities of these enzymes increased. In the SV3T3 cells, the activities of all the enzymes except for monoamine oxidase decreased from sparse to confluent culture densities in cells grown in 10% n.c.s. whereas in those grown in 10% f.b.s. there were no significant change in the activities of the enzymes over the same culture densities. The results suggest that the marker enzymes are affected by sera types and culture densities.
    Matched MeSH terms: Cells, Cultured
  10. (-)-Grandisin form Cryptocarya crassinervia
    Saad JM, Soepadamo E, Fang XP, McLaughlin JL, Fanwick PE
    J Nat Prod, 1991 11 1;54(6):1681-3.
    PMID: 1812217
    The known lignan (-)-grandisin [1] has been isolated from Cryptocarya crassinervia by using the brine shrimp lethality test to direct the isolation; its structure and relative stereochemistry have been determined by ir, 1H nmr, ms, and X-ray crystallography as an all-trans alpha, alpha'-diaryl-beta, beta'-dimethyltetrahydrofuran. Compound 1 is not significantly cytotoxic in our panel of human tumor cells.
    Matched MeSH terms: Tumor Cells, Cultured
  11. Mycobacterium leprae reactive T cell clones from lepromatous leprosy patients after prolonged dapsone chemotherapy
    Gill HK, Ridley DS, Ganesan J, Mustafa AS, Rees RJ, Godal T
    Lepr Rev, 1990 Mar;61(1):25-31.
    PMID: 2181222
    The proliferative responses of peripheral blood mononuclear cells (PBMC) to Mycobacterium leprae and BCG were studied in two groups of leprosy patients: a group of 8 lepromatous patients who had been on treatment for more than 20 years (TLL) and a group of 8 untreated lepromatous leprosy patients (ULL). The mean response to M. leprae of the TLL group was 6195 cpm with 5 of the 8 patients responding positively. The mean response to M. leprae of the ULL group was 617 cpm, with only 1 patient showing a positive response. The corresponding proliferative responses to BCG were 19,908 cpm in the TLL group and 7908 in the ULL group. Thirteen M. leprae reactive clones were established from 2 TLL patients and 5 M. leprae reactive clones were established from 2 tuberculoid leprosy patients. Seven of these clones, 4 from the TLL patients and 3 from the tuberculoid (TT) patients could be studied further. Three of the TLL clones responded specifically to M. leprae, while one of the clones exhibited a broad cross-reactivity to other mycobacteria. All of these clones were of the CD4+CD8- phenotype. Our findings suggest that responsiveness to M. leprae can be detected in vitro in a proportion of LL patients who have undergone prolonged chemotherapy, and that this response involves M. leprae reactive CD8+CD8- T cells, of which some appear to be specific to M. leprae.
    Matched MeSH terms: Clone Cells
  12. Influence of recombinant interferon-gamma QN the expression of MHC class I and class II antigens on four human colonic carcinoma cell lines
    Norazmi MN, Hohmann AW, Bradley J
    Malays J Pathol, 1990 Dec;12(2):89-95.
    PMID: 2129402
    The occurrence of MHC class I and class II antigens on four human colonic carcinoma cell lines and the effect of recombinant interferon-gamma (rIFNg) on the expression of these antigens was investigated by immunofluorescent flow cytometry. The concentration of rIFNg which resulted in the largest increase in expression of class I and class II antigens was determined. Changes in the amount of MHC antigen on the membrane were indicated by a shift in the mean fluorescence intensity (MFI) of the cell population. Without addition of rIFNg, the COLO 206, COLO 320F and COLO 397 cell lines were class I positive although the COLO 206 cell line expressed less class I antigen than the other two lines. The HT-29 cell line expressed only a minimal level of class I antigen. Treatment with rIFNg increased the amount of class I antigen on these cell lines 5, 1.4, 2.5 and 20 times respectively. Maximum levels of class I antigen were found two days after treatment. Class I antigen expression returned to pre-treatment levels by day 8 in all but the HT-29 cell line, which maintained its increased level following a single dose of rIFNg. All four cell lines had little or no class II antigens. Following treatment with rIFNg, DR antigen appeared on all four lines whereas DP and DQ antigens could be induced only on the 320F and 397 lines. The amount of class II antigen reached its peak two days after treatment and gradually decreased over the next 6 days of culture.(ABSTRACT TRUNCATED AT 250 WORDS)
    Matched MeSH terms: Tumor Cells, Cultured
  13. A new flavonoid and sulphur-containing amides from Glycosmis chlorosperma
    Rahmani M, Leng KW, Ismail HB, Hin TY, Sukari MA, Ali AM, et al.
    Nat Prod Res, 2004 Feb;18(1):85-8.
    PMID: 14974620
    A new flavonoid, dihydroglychalcone-A, was isolated from the leaves extract of Glycosmis chlorosperma in addition to two known sulphur-containing amides, dambullin and gerambullin. The structure of the new compound was assigned as 2'-hydroxy-4,6'-dimethoxy-3',4'-(2",2"-dimethylpyrano)dihydrochalcone. The extract of the leaves was also found to exhibit antimicrobial and cytotoxic activities.
    Matched MeSH terms: Tumor Cells, Cultured
  14. Mucigerin, a new coumarin from Calophyllum mucigerum (Guttiferae)
    Ee GC, Ng KN, Taufiq-Yap YH, Rahmani M, Ali AM, Muse R
    Nat Prod Res, 2004 Apr;18(2):123-8.
    PMID: 14984084
    Our recent studies on the stem bark of Calophyllum mucigerum (Guttiferae) have yielded a new coumarin mucigerin, a prenylated xanthone cudraxanthone C and the common steroidal triterpenes friedelin and stigmasterol. Structural elucidations of these compounds were achieved using 1H NMR, 13C NMR, DEPT, COSY, HETCOR and HMBC experiments while MS gave the molecular masses. Cytotoxic assays using CEM-SS cell line (T-lymphoblastic leukemia) on the crude extracts of the stem bark indicated some activity. The crude extracts were also found to be moderately toxic against the larvae of Aedes aegypti. This article reports the isolation and identification of mucigerin as well as bioassay data.
    Matched MeSH terms: Tumor Cells, Cultured
  15. Nickel and zinc complexes of testosterone N4-substituted thiosemicarbazone: Selective cytotoxicity towards human colorectal carcinoma cell line HCT 116 and their cell death mechanisms
    Heng MP, Sim KS, Tan KW
    J Inorg Biochem, 2020 07;208:111097.
    PMID: 32438269 DOI: 10.1016/j.jinorgbio.2020.111097
    Two new Schiff base ligands (TE and TF) were prepared from conjugation of testosterone with 4-(4-ethylphenyl)-3-thiosemicarbazide and 4-(4-fluorophenyl)-3-thiosemicarbazide, respectively. Their nickel (NE and NF) and zinc (ZE and ZF) complexes were reported. X-ray crystallography revealed a distorted square planar geometry was adopted by NE. The compounds demonstrated excellent selectivity towards the colorectal carcinoma cell line HCT 116 despite their weak preferences towards the prostate cancer cell lines (PC-3 and LNCaP). Against HCT 116, all these compounds were able to arrest cell cycle at G0/G1 phase and induce apoptosis via mitochondria-dependent (TE, NE, and TF) and extrinsic apoptotic pathway (ZE, NF, and ZF). Moreover, only ZE was able to act as topoisomease I poison and halt its enzymatic reactions although all compounds presented excellent affinity towards DNA.
    Matched MeSH terms: HCT116 Cells
  16. Inhibition of cell migration and invasion by miR‑29a‑3p in a colorectal cancer cell line through suppression of CDC42BPA mRNA expression
    He PY, Yip WK, Chai BL, Chai BY, Jabar MF, Dusa N, et al.
    Oncol Rep, 2017 Dec;38(6):3554-3566.
    PMID: 29039592 DOI: 10.3892/or.2017.6037
    The objective of this study was to determine the effect of miR‑29a‑3p inhibitor on the migration and invasion of colorectal cancer cell lines (CRC) and the underlying molecular mechanisms. miR‑29a‑3p was detected using reverse transcription-quantitative polymerase chain reaction (RT‑qPCR) in the CRC cell lines HCT11, CaCo2, HT29, SW480 and SW620. An invasive subpopulation designated SW480‑7 was derived from the parental cell line, detected by Transwell and Transwell Matrigel assays. Cytoskeleton Regulators RT2 profiler PCR array and western blot analysis were utilized to identify the alterations in expression of downstream mRNAs. siRNA against CDC42BPA was transfected into SW480‑7 and effects on cell migration and invasion were investigated. Data obtained showed that miR‑29a‑3p was detected in these five CRC cell lines. miR‑29a‑3p inhibitor had no effect on viability but stimulated cell migration and invasion of SW480‑7 cells. In contrast, miR‑29a‑3p mimic suppressed cell migration and invasion. TargetScan miRBD and DIANA were employed to identify the potential direct target genes of miR‑29a‑3p in the Cytoskeleton Regulators RT2-Profiler PCR array. Cytoskeleton Regulators RT2-Profiler PCR array data showed that 3 out of the 5 predicted targets genes, CDC42BPA (2.33-fold), BAIAP2 (1.79-fold) and TIAM1 (1.77-fold), in the array were upregulated by miR‑29a‑3p. A significant increase in expression IQGAP2, PHLDB2, SSH1 mRNAs and downregulation of PAK1 mRNA was also detected with miR‑29a‑3p inhibition. Increase in CDC42BPA, SSH1 and IQGAP2 mRNA expression correlated with increased protein level in miR‑29a‑3p transfected SW-480-7 cells. Silencing of CDC42BPA (an enhancer of cell motility) partially abolished miR‑29a‑3p inhibitor-induced stimulation of cell migration and invasion. miR‑29a‑3p expression in stage II and III CRC is relatively lower than that of stage I CRC. However, the data need to be interpreted with caution due to the small sample size. In conclusion, inhibition of miR‑29a‑3p stimulates SW480‑7 cell migration and invasion and downstream expression IQGAP2, PHLDB2, SSH1 mRNAs are upregulated whilst PAK1 mRNA is downregulated. Silencing of CDC42BPA expression partially reduces miR29a‑3p inhibitor-induced migration and invasion of SW480‑7 cells.
    Matched MeSH terms: Caco-2 Cells
  17. Modeling and development of screen-printed impedance biosensor for cytotoxicity studies of lung carcinoma cells
    Mansor AFM, Ibrahim I, Zainuddin AA, Voiculescu I, Nordin AN
    Med Biol Eng Comput, 2018 Jan;56(1):173-181.
    PMID: 29247387 DOI: 10.1007/s11517-017-1756-1
    Electrical cell-substrate impedance sensing (ECIS) is a powerful technique to monitor real-time cell behavior. In this study, an ECIS biosensor formed using two interdigitated electrode structures (IDEs) was used to monitor cell behavior and its response to toxicants. Three different sensors with varied electrode spacing were first modeled using COMSOL Multiphysics and then fabricated and tested. The silver/silver chloride IDEs were fabricated using a screen-printing technique and incorporated with polydimethylsiloxane (PDMS) cell culture wells. To study the effectiveness of the biosensor, A549 lung carcinoma cells were seeded in the culture wells together with collagen as an extracellular matrix (ECM) to promote cell attachment on electrodes. A549 cells were cultured in the chambers and impedance measurements were taken at 12-h intervals for 120 h. Cell index (CI) for both designs were calculated from the impedance measurement and plotted in comparison with the growth profile of the cells in T-flasks. To verify that the ECIS biosensor can also be used to study cell response to toxicants, the A549 cells were also treated with anti-cancer drug, paclitaxel, and its responses were monitored over 5 days. Both simulation and experimental results show better sensitivity for smaller spacing between electrodes. Graphical abstract The fabricated impedance biosensor used screen-printed silver/silver chloride IDEs. Simulation and experimental results show better sensitivity for smaller between electrodes.
    Matched MeSH terms: A549 Cells
  18. Fulltext N-glycosylation and expression in human tissues of the orphan GPR61 receptor
    Kozielewicz P, Alomar H, Yusof S, Grafton G, Cooper AJ, Curnow SJ, et al.
    FEBS Open Bio, 2017 12;7(12):1982-1993.
    PMID: 29226084 DOI: 10.1002/2211-5463.12339
    A number of members of the G protein-coupled receptor class of cell surface receptors are 'orphans' with no known endogenous ligand. One of these orphan receptors is GPR61; there are little data about its expression in human cells and tissues. In this study, we investigated the post-translational modification of GPR61 by N-glycosylation at an identified consensus N-glycosylation site (N12) and the impact of this modification upon the subcellular expression of the protein. The N-glycosylation inhibitor tunicamycin reduced the apparent molecular weight of immunoreactivity associated with myc-tagged GPR61 by 1-2 kDa, which was comparable to the evident molecular weight of the myc-tagged N12S GPR61 mutant with disrupted consensus N-glycosylation site. Analysis of GPR61 expression demonstrated that tunicamycin treatment reduced considerably heterologous expression of GPR61 in the cell membrane despite the N12S GPR61 mutant being readily expressed at the cell surface. These results demonstrate that GPR61 is subject to N-glycosylation but suggest this is not a prerequisite for cell surface expression, although N-glycosylation of other proteins may be important for cell membrane expression of GPR61. Expression of GPR61 protein was demonstrated at the cellular level in human hippocampus and human peripheral blood mononuclear cells. In the latter, there was a significantly higher expression of GPR61 in the Th17 cell subset in comparison with resting CD4+ cells, which may point toward a potential role for the GPR61 receptor in autoimmune diseases. This is the first report that GPR61 protein is subject to post-translational modification and is expressed in immune cell subsets and the hippocampus. These findings will help guide studies to investigate the function of GPR61.
    Matched MeSH terms: Th17 Cells
  19. Fulltext Mitragynine, an euphoric compound inhibits hERG1a/1b channel current and upregulates the complexation of hERG1a-Hsp90 in HEK293-hERG1a/1b cells
    Tay YL, Amanah A, Adenan MI, Wahab HA, Tan ML
    Sci Rep, 2019 12 24;9(1):19757.
    PMID: 31874991 DOI: 10.1038/s41598-019-56106-6
    Mitragyna speciosa Korth (M. speciosa) has been widely used as a recreational product, however, there are growing concerns on the abuse potentials and toxicity of the plant. Several poisoning and fatal cases involving kratom and mitragynine have been reported but the underlying causes remain unclear. The human ether-a-go-go-related gene 1 (hERG1) encodes the pore-forming subunit underlying cardiac rapidly delayed rectifier potassium current (IKr). Pharmacological blockade of the IKr can cause acquired long QT syndrome, leading to lethal cardiac arrhythmias. This study aims to elucidate the mechanisms of mitragynine-induced inhibition on hERG1a/1b current. Electrophysiology experiments were carried out using Port-a-Patch system. Quantitative RT-PCR, Western blot analysis, immunofluorescence and co-immunoprecipitation methods were used to determine the effects of mitragynine on hERG1a/1b expression and hERG1-cytosolic chaperones interaction. Mitragynine was found to inhibit the IKr current with an IC50 value of 332.70 nM. It causes a significant reduction of the fully-glycosylated (fg) hERG1a protein expression but upregulates both core-glycosylated (cg) expression and hERG1a-Hsp90 complexes, suggesting possible impaired hERG1a trafficking. In conclusion, mitragynine inhibits hERG1a/1b current through direct channel blockade at lower concentration, but at higher concentration, it upregulates the complexation of hERG1a-Hsp90 which may be inhibitory towards channel trafficking.
    Matched MeSH terms: HEK293 Cells
  20. Fulltext Treatment of spinal cord injury with mesenchymal stem cells
    Liau LL, Looi QH, Chia WC, Subramaniam T, Ng MH, Law JX
    Cell Biosci, 2020;10:112.
    PMID: 32983406 DOI: 10.1186/s13578-020-00475-3
    Background: Spinal cord injury (SCI) is the damage to the spinal cord that can lead to temporary or permanent loss of function due to injury to the nerve. The SCI patients are often associated with poor quality of life.

    Results: This review discusses the current status of mesenchymal stem cell (MSC) therapy for SCI, criteria to considering for the application of MSC therapy and novel biological therapies that can be applied together with MSCs to enhance its efficacy. Bone marrow-derived MSCs (BMSCs), umbilical cord-derived MSCs (UC-MSCs) and adipose tissue-derived MSCs (ADSCs) have been trialed for the treatment of SCI. Application of MSCs may minimize secondary injury to the spinal cord and protect the neural elements that survived the initial mechanical insult by suppressing the inflammation. Additionally, MSCs have been shown to differentiate into neuron-like cells and stimulate neural stem cell proliferation to rebuild the damaged nerve tissue.

    Conclusion: These characteristics are crucial for the restoration of spinal cord function upon SCI as damaged cord has limited regenerative capacity and it is also something that cannot be achieved by pharmacological and physiotherapy interventions. New biological therapies including stem cell secretome therapy, immunotherapy and scaffolds can be combined with MSC therapy to enhance its therapeutic effects.

    Matched MeSH terms: Neural Stem Cells
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