Displaying publications 401 - 420 of 690 in total

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  1. Supermacroporous poly(vinyl alcohol)-carboxylmethyl chitosan-poly(ethylene glycol) scaffold: an in vitro and in vivo pre-assessments for cartilage tissue engineering
    Lee SY, Wee AS, Lim CK, Abbas AA, Selvaratnam L, Merican AM, et al.
    J Mater Sci Mater Med, 2013 Jun;24(6):1561-70.
    PMID: 23512151 DOI: 10.1007/s10856-013-4907-4
    This study aims to pre-assess the in vitro and in vivo biocompatibility of poly(vinyl alcohol)-carboxylmethyl-chitosan-poly(ethylene glycol) (PCP) scaffold. PCP was lyophilised to create supermacroporous structures. 3-(4, 5-dimethyl-thiazol-2yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and immunohistochemistry (IHC) were used to evaluate the effectiveness of PCP scaffolds for chondrocytes attachment and proliferation. The ultrastructural was assessed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Extracellular matrix (ECM) formation was evaluated using collagen type-II staining, glycosaminoglycan (GAG) and collagen assays. Histological analysis was conducted on 3-week implanted Sprague-Dawley rats. The MTT, IHC, SEM and TEM analyses confirm that PCP scaffolds promoted cell attachment and proliferation in vitro. The chondrocyte-PCP constructs secreted GAG and collagen type-II, both increased significantly from day-14 to day-28 (P 
    Matched MeSH terms: Cells, Cultured
  2. Fulltext Rhaphidophora korthalsii modulates peripheral blood natural killer cell proliferation, cytokine secretion and cytotoxicity
    Yeap SK, Omar AR, Ho WY, Beh BK, Ali AM, Alitheen NB
    BMC Complement Altern Med, 2013;13:145.
    PMID: 23800124 DOI: 10.1186/1472-6882-13-145
    Rhaphidophora korthalsii (Araceae) is a root-climber plant which has been widely used in Chinese traditional medicine for cancer and skin disease treatment. Previous reports have recorded its immunomodulatory effects on mice splenocyte and human peripheral blood. This study investigated the potential immunostimulatory effect of Rhaphidophora korthalsii on human PBMC enriched NK cell.
    Matched MeSH terms: Cells, Cultured
  3. Fulltext The potential of intra-articular injection of chondrogenic-induced bone marrow stem cells to retard the progression of osteoarthritis in a sheep model
    Al Faqeh H, Nor Hamdan BM, Chen HC, Aminuddin BS, Ruszymah BH
    Exp Gerontol, 2012 Jun;47(6):458-64.
    PMID: 22759409 DOI: 10.1016/j.exger.2012.03.018
    In recent years, the use of bone marrow mesenchymal stem cell (BMSC) implantation has provided an alternative treatment for osteoarthritis. The objective of this study is to determine whether or not an intra-articular injection of a single dose of autologous chondrogenic induced BMSC could retard the progressive destruction of cartilage in a surgically induced osteoarthritis in sheep. Sheep BMSCs were isolated and divided into two groups. One group was cultured in chondrogenic media containing (Ham's F12:DMEM, 1:1) FD+1% FBS+5 ng/ml TGFβ3+50 ng/ml IGF-1 (CM), and the other group was cultured in the basal media, FD+10% FBS (BM). The procedure for surgically induced osteoarthritis was performed on the donor sheep 6 weeks prior to intra-articular injection into the knee joint of a single dose of BMSC from either group, suspended in 5 ml FD at density of 2 million cells/ml. The control groups were injected with basal media, without cells. Six weeks after injection, gross evidence of retardation of cartilage destruction was seen in the osteoarthritic knee joints treated with CM as well as BM. No significant ICRS (International Cartilage Repair Society) scoring was detected between the two groups with cells. However macroscopically, meniscus repair was observed in the knee joint treated with CM. Severe osteoarthritis and meniscal injury was observed in the control group. Interestingly, histologically the CM group demonstrated good cartilage histoarchitecture, thickness and quality, comparable to normal knee joint cartilage. As a conclusion, intra-articular injection of a single dose of BMSC either chondrogenically induced or not, could retard the progression of osteoarthritis (OA) in a sheep model, but the induced cells indicated better results especially in meniscus regeneration.
    Study site: Universiti Kebangsaan Malaysia, Kuala Lumpur
    Matched MeSH terms: Cells, Cultured
  4. Fulltext Acute toxicity evaluation, antibacterial, antioxidant and immunomodulatory effects of Melastoma malabathricum
    Alnajar ZA, Abdulla MA, Ali HM, Alshawsh MA, Hadi AH
    Molecules, 2012;17(3):3547-59.
    PMID: 22433579 DOI: 10.3390/molecules17033547
    Melastoma malabathricum (MM) is a well-known plant in Malaysian traditional medicine, locally known as senduduk. Its ethanol and aqueous extracts have been used in the present investigation to study the immunomodulatory role on human peripheral blood mononuclear cell (PBMC), and the DPPH, ABTS and FRAP free radical scavenging activities were also measured. Total flavonoids and total phenolic contents were assayed and the antibacterial effect was tested against four species of bacteria; two Gram-positive (Staphylococcus aureus and Streptococcus agalactiae) and two Gram-negative (Escherichia coli and Klebsilla pneumonia). The tests were carried out using the disc diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods. Moreover, the acute toxicity was evaluated in vivo on the ethanol extract of MM to establish its safety when administered orally. In our results, both extracts of MM showed abilities to scavenge DPPH and ABTS free radicals, IC(50) values: (11.599 ± 0.84, 10.573 ± 0.58 µmol/L) and (62.657 ± 0.78, 63.939 ± 0.48 µmol/L) for ethanol and aqueous extracts respectively. Indeed the ethanol extract evidenced high phenolic content (384.33 ± 0.005 mg/g), flavonoids contents (85.8 ± 0.009 mg/g) and ferric reducing antioxidant power (33,590 ± 0.038 mmol/g), with high activity against S. aureus and S. agalactiae (11 ± 0.3 and 12 ± 0.6 mm inhibition zones). Likewise, the percentage of peripheral blood mononuclear cells (PBMC) viability was increased in response to MM, IC(50) values (1.781 ± 1.2 and 6.545 ± 0.93 µg/mL) for ethanol and aqueous extracts, respectively. In addition, our results showed that the MM extract is safe even at a high dose of 5,000 mg/kg and has no oral toxicity. These findings suggest the excellent medicinal bioactivity of MM and explain the popularity of this plant in the folk medicine as a remedy for different illnesses.
    Matched MeSH terms: Cells, Cultured
  5. Fulltext Neuroprotective effects of germinated brown rice against hydrogen peroxide induced cell death in human SH-SY5Y cells
    Ismail N, Ismail M, Fathy SF, Musa SN, Imam MU, Foo JB, et al.
    Int J Mol Sci, 2012;13(8):9692-708.
    PMID: 22949825 DOI: 10.3390/ijms13089692
    The neuroprotective and antioxidative effects of germinated brown rice (GBR), brown rice (BR) and commercially available γ-aminobutyric acid (GABA) against cell death induced by hydrogen peroxide (H(2)O(2)) in human neuroblastoma SH-SY5Y cells have been investigated. Results show that GBR suppressed H(2)O(2)-mediated cytotoxicity and induced G0/G1 phase cell cycle arrest in SH-SY5Y cells. Moreover, GBR reduced mitochondrial membrane potential (MMP) and prevented phosphatidylserine (PS) translocation in SH-SY5Y cells, key features of apoptosis, and subsequent cell death. GBR exhibited better neuroprotective and antioxidative activities as compared to BR and GABA. These results indicate that GBR possesses high antioxidative activities and suppressed cell death in SH-SY5Y cells by blocking the cell cycle re-entry and apoptotic mechanisms. Therefore, GBR could be developed as a value added functional food to prevent neurodegenerative diseases caused by oxidative stress and apoptosis.
    Matched MeSH terms: Tumor Cells, Cultured
  6. Effects of epidermal growth factor on the proliferation and cell cycle regulation of cultured human amnion epithelial cells
    Fatimah SS, Tan GC, Chua KH, Tan AE, Hayati AR
    J Biosci Bioeng, 2012 Aug;114(2):220-7.
    PMID: 22578596 DOI: 10.1016/j.jbiosc.2012.03.021
    Human amnion epithelial cells (HAECs) hold great promise in tissue engineering for regenerative medicine. Large numbers of HAECs are required for this purpose. Hence, exogenous growth factor is added to the culture medium to improve epithelial cells proliferation. The aim of the present study was to determine the effects of epidermal growth factor (EGF) on the proliferation and cell cycle regulation of cultured HAECs. HAECs at P1 were cultured for 7 days in medium containing an equal volume mix of HAM's F12: Dulbecco's Modified Eagles Medium (1:1) supplemented with different concentrations of EGF (0, 5, 10, 20, 30 and 50 ng/ml EGF) in reduced serum. Morphology, growth kinetics and cell cycle analysis using flow cytometry were assessed. Quantitative gene expression for cell cycle control genes, pluripotent transcription factors, epithelial genes and neuronal genes were also determined. EGF enhanced HAECs proliferation with optimal concentration at 10 ng/ml EGF. EGF significantly increased the proportion of HAECs at S- and G2/M-phase of the cell cycle compared to the control. At the end of culture, HAECs remained as diploid cells under cell cycle analysis. EGF significantly decreased the mRNA expression of p21, pRb, p53 and GADD45 in cultured HAECs. EGF also significantly decreased the pluripotent genes expression: Oct-3/4, Sox2 and Nanog; epithelial genes expression: CK14, p63, CK1 and Involucrin; and neuronal gene expression: NSE, NF-M and MAP 2. The results suggested that EGF is a strong mitogen that promotes the proliferation of HAECs through cell cycle regulation. EGF did not promote HAECs differentiation or pluripotent genes expression.
    Matched MeSH terms: Cells, Cultured
  7. Fulltext Human respiratory epithelial cells from nasal turbinate expressed stem cell genes even after serial passaging
    Ruszymah BH, Izham BA, Heikal MY, Khor SF, Fauzi MB, Aminuddin BS
    Med J Malaysia, 2011 Dec;66(5):440-2.
    PMID: 22390097 MyJurnal
    Current development in the field of tissue engineering led to the idea of repairing and regenerating the respiratory airway through in vitro reconstruction using autologous respiratory epithelial (RE). To ensure the capability of proliferation, the stem cell property of RE cells from the nasal turbinate should be evaluated. Respiratory epithelial cells from six human nasal turbinates were harvested and cultured in vitro. The gene expression of FZD-9 and BST-1 were expressed in passage 2 (P2) and passage 4 (P4). The levels of expression were not significant between both passages. The RE cells exhibit the stem cell properties, which remains even after serial passaging.
    Matched MeSH terms: Cells, Cultured
  8. Identification of suitable culture condition for expansion and osteogenic differentiation of human bone marrow stem cells
    Chowdhury SR, Ng MH, Hassan NS, Aminuddin BS, Ruszymah BH
    Hum. Cell, 2012 Sep;25(3):69-77.
    PMID: 22968953
    This study was undertaken in order to identify the best culture strategy to expand and osteogenic differentiation of human bone marrow stem cells (hBMSCs) for subsequent bone tissue engineering. In this regard, the experiment was designed to evaluate whether it is feasible to bypass the expansion phase during hBMSCs differentiation towards osteogenic lineages by early induction, if not identification of suitable culture media for enhancement of hBMSCs expansion and osteogenic differentiation. It was found that introduction of osteogenic factors in alpha-minimum essential medium (αMEM) during expansion phase resulted in significant reduction of hBMSCs growth rate and osteogenic gene expressions. In an approach to identify suitable culture media, the growth and differentiation potential of hBMSCs were evaluated in αMEM, F12:DMEM (1:1; FD), and FD with growth factors. It was found that αMEM favors the expansion and osteogenic differentiation of hBMSCs compared to that in FD. However, supplementation of growth factors in FD, only during expansion phase, enhances the hBMSCs growth rate and significantly up-regulates the expression of CBFA-1 (the early markers of osteogenic differentiation) during expansion, and, other osteogenic genes at the end of induction compared to the cells in αMEM and FD. These results suggested that the expansion and differentiation phase of the hBMSCs should be separately and carefully timed. For bone tissue engineering, supplementation of growth factors in FD only during the expansion phase was sufficient to promote hBMSCs expansion and differentiation, and preferably the most efficient culture condition.
    Matched MeSH terms: Cells, Cultured
  9. Alteration of gene expression levels during osteogenic induction of human adipose derived stem cells in long-term culture
    Safwani WK, Makpol S, Sathapan S, Chua KH
    Cell Tissue Bank, 2013 Jun;14(2):289-301.
    PMID: 22476937 DOI: 10.1007/s10561-012-9309-1
    Adipose tissue is a source of multipotent stem cells and it has the ability to differentiate into several types of cell lineages such as neuron cells, osteogenic and adipogenic cells. Most studies on human adipose-derived stem cells (ASCs) have been carried out at the early passages. For clinical usage, ASCs need to be expanded in vitro for a period of time to get sufficient cells for transplantation into patients. However, the impact of long-term culture on ASCs molecular characteristics has not been established yet. Several studies have also shown that osteogenic and adipogenic cells have the ability to switch pathways during in vitro culture as they share the same progenitor cells. This data is important to ensure their functionality and efficacy before being used clinically in the treatment of bone diseases. Therefore, we aim to investigate the effect of long-term culture on the adipogenic, stemness and osteogenic genes expression during osteogenic induction of ASCs. In this study, the molecular characteristics of ASCs during osteogenic induction in long-term culture was analysed by observing their morphological changes during induction, analysis of cell mineralization using Alizarin Red staining and gene expression changes using quantitative RT-PCR. Morphologically, cell mineralization at P20 was less compared to P5, P10 and P15. Adipogenesis was not observed as negative lipid droplets formation was recorded during induction. The quantitative PCR data showed that adipogenic genes expression e.g. LPL and AP2 decreased but PPAR-γ was increased after osteogenic induction in long-term culture. Most stemness genes decreased at P5 and P10 but showed no significant changes at P15 and P20. While most osteogenic genes increased after osteogenic induction at all passages. When compared among passages after induction, Runx showed a significant increased at P20 while BSP, OSP and ALP decreased at later passage (P15 and P20). During long-term culture, ASCs were only able to differentiate into immature osteogenic cells.
    Matched MeSH terms: Cells, Cultured
  10. Fulltext Lethal Nipah virus infection induces rapid overexpression of CXCL10
    Mathieu C, Guillaume V, Sabine A, Ong KC, Wong KT, Legras-Lachuer C, et al.
    PLoS One, 2012;7(2):e32157.
    PMID: 22393386 DOI: 10.1371/journal.pone.0032157
    Nipah virus (NiV) is a recently emerged zoonotic Paramyxovirus that causes regular outbreaks in East Asia with mortality rate exceeding 75%. Major cellular targets of NiV infection are endothelial cells and neurons. To better understand virus-host interaction, we analyzed the transcriptome profile of NiV infection in primary human umbilical vein endothelial cells. We further assessed some of the obtained results by in vitro and in vivo methods in a hamster model and in brain samples from NiV-infected patients. We found that NiV infection strongly induces genes involved in interferon response in endothelial cells. Among the top ten upregulated genes, we identified the chemokine CXCL10 (interferon-induced protein 10, IP-10), an important chemoattractant involved in the generation of inflammatory immune response and neurotoxicity. In NiV-infected hamsters, which develop pathology similar to what is seen in humans, expression of CXCL10 mRNA was induced in different organs with kinetics that followed NiV replication. Finally, we showed intense staining for CXCL10 in the brain of patients who succumbed to lethal NiV infection during the outbreak in Malaysia, confirming induction of this chemokine in fatal human infections. This study sheds new light on NiV pathogenesis, indicating the role of CXCL10 during the course of infection and suggests that this chemokine may serve as a potential new marker for lethal NiV encephalitis.
    Matched MeSH terms: Cells, Cultured
  11. Fulltext Development of antiproliferative nanohybrid compound with controlled release property using ellagic acid as the active agent
    Hussein MZ, Al Ali SH, Zainal Z, Hakim MN
    Int J Nanomedicine, 2011;6:1373-83.
    PMID: 21796241 DOI: 10.2147/IJN.S21567
    An ellagic acid (EA)-zinc layered hydroxide (ZLH) nanohybrid (EAN) was synthesized under a nonaqueous environment using EA and zinc oxide (ZnO) as the precursors. Powder X-ray diffraction showed that the basal spacing of the nanohybrid was 10.4 Å, resulting in the spatial orientation of EA molecules between the interlayers of 22.5° from z-axis with two negative charges at 8,8' position of the molecules pointed toward the ZLH interlayers. FTIR study showed that the intercalated EA spectral feature is generally similar to that of EA, but with bands slightly shifted. This indicates that some chemical bonding of EA presence between the nanohybrid interlayers was slightly changed, due to the formation of host-guest interaction. The nanohybrid is of mesopores type with 58.8% drug loading and enhanced thermal stability. The release of the drug active, EA from the nanohybrid was found to be sustained and therefore has good potential to be used as a drug controlled-release formulation. In vitro bioassay study showed that the EAN has a mild effect on the hepatocytes cells, similar to its counterpart, free EA.
    Matched MeSH terms: Cells, Cultured
  12. Fulltext Triterpene composition and bioactivities of Centella asiatica
    Hashim P, Sidek H, Helan MH, Sabery A, Palanisamy UD, Ilham M
    Molecules, 2011;16(2):1310-22.
    PMID: 21278681 DOI: 10.3390/molecules16021310
    Leaves of Centella asiatica (Centella) were analysed for their triterpene composition and bioactivity such as collagen enhancement, antioxidant, anticellulite and UV protection capacity properties. Triterpenes of Centella were measured using HPLC-PAD on an Excil ODS 5 mm (C18) column for the simultaneous determination of asiatic acid, madecassic acid, asiaticoside and madecassoside. Centella was found to contain significant amounts of madecassoside (3.10 ± 4.58 mg/mL) and asiaticoside (1.97 ± 2.65 mg/mL), but was low in asiatic and madecassic acid. The highest collagen synthesis was found at 50 mg/mL of Centella extracts. The antioxidant activity of Centella (84%) was compared to grape seed extract (83%) and Vitamin C (88%). Its lipolytic activity was observed by the release of glycerol (115.9 µmol/L) at 0.02% concentration. Centella extracts exhibited similar UV protection effect to OMC at 10% concentration. In view of these results, the potential application of Centella in food and pharmaceutical industries is now widely open.
    Matched MeSH terms: Cells, Cultured
  13. Fulltext Effect of experimental treatment on GAPDH mRNA expression as a housekeeping gene in human diploid fibroblasts
    Zainuddin A, Chua KH, Abdul Rahim N, Makpol S
    BMC Mol. Biol., 2010;11:59.
    PMID: 20707929 DOI: 10.1186/1471-2199-11-59
    Several genes have been used as housekeeping genes and choosing an appropriate reference gene is important for accurate quantitative RNA expression in real time RT-PCR technique. The expression levels of reference genes should remain constant between the cells of different tissues and under different experimental conditions. The purpose of this study was to determine the effect of different experimental treatments on the expression of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA so that the reliability of GAPDH as reference gene for quantitative real time RT-PCR in human diploid fibroblasts (HDFs) can be validated. HDFs in 4 different treatment groups viz; young (passage 4), senescent (passage 30), H2O2-induced oxidative stress and gamma-tocotrienol (GTT)-treated groups were harvested for total RNA extraction. Total RNA concentration and purity were determined prior to GAPDH mRNA quantification. Standard curve of GAPDH expression in serial diluted total RNA, melting curve analysis and agarose gel electrophoresis were used to determine the reliability of GAPDH as reference gene.
    Matched MeSH terms: Cells, Cultured
  14. Fulltext Characterisation of the binding properties of Bacillus thuringiensis 18 toxin on leukaemic cells
    Wong RS, Mohamed SM, Nadarajah VD, Tengku IA
    J Exp Clin Cancer Res, 2010;29:86.
    PMID: 20591169 DOI: 10.1186/1756-9966-29-86
    Various strains of Bacillus thuringiensis (Bt) have been found to produce parasporal proteins that are cytotoxic to human cancer cells. This study aims to establish the binding affinity of purified Bt 18 toxin for CEM-SS (T lymphoblastic leukaemia cell line), to determine if competition exists between the toxin and commercial anticancer drugs for the binding site on CEM-SS and to localise the binding site of the toxin on CEM-SS.
    Matched MeSH terms: Cells, Cultured
  15. Human chorion-derived stem cells: changes in stem cell properties during serial passage
    Fariha MM, Chua KH, Tan GC, Tan AE, Hayati AR
    Cytotherapy, 2011 May;13(5):582-93.
    PMID: 21231803 DOI: 10.3109/14653249.2010.549121
    BACKGROUND AIMS: Fetal membrane from human placenta tissue has been described as a potential source of stem cells. Despite abundant literature on amnion stem cells, there are limited studies on the stem cell properties of chorion-derived stem cells.

    METHODS: The main aim was to determine the stemness properties of serial-passaged human chorion-derived stem cells (hCDSC). Quantitative polymerase chain reaction (PCR) was performed to reveal the following stemness gene expression in serial-passaged hCDSC: Oct-4, Sox-2, FGF-4, Rex-1, TERT, Nanog (3), Nestin, FZD-9, ABCG-2 and BST-1. Cell growth rate was evaluated from passage (P) 1 until P5. The colony-forming unit-fibroblast (CFU-F) frequency of P3 and P5 cells and multilineage differentiation potential of P5 cells were determined. The immunophenotype of hCDSC was compared using the surface markers CD9, CD31, CD34, CD44, CD45, CD73, CD90, CD117, HLA-ABC and HLA-DR, -DP and -DQ. Immunostaining for trophoblast markers was done on P0, P1, P3 and P5 cells to detect the contamination of trophoblasts in culture, while chromosomal abnormality was screened by cytogenetic analysis of P5 cells.

    RESULTS: The surface markers for mesenchymal lineage in hCDSC were more highly expressed at P5 compared with P3 and P0, indicating the increased purity of these stem cells after serial passage. Indeed, all the stemness genes except TERT were expressed at P1, P3 and P5 hCDSC. Furthermore, human chorion contained high clonogenic precursors with a 1:30 CFU-F frequency. Successful adipogenic, chondrogenic and osteogenic differentiation demonstrated the multilineage potential of hCDSC. The karyotyping analysis showed hCDSC maintained chromosomal stability after serial passage.

    CONCLUSIONS: hCDSC retain multipotent potential even at later passages, hence are a promising source for cell therapy in the future.

    Matched MeSH terms: Cells, Cultured
  16. Effect of exogenous nitric oxide on murine splenic immune response induced by Aggregatibacter actinomycetemcomitans lipopolysaccharide
    Sosroseno W, Bird PS, Seymour GJ
    Anaerobe, 2009 Jun;15(3):95-8.
    PMID: 19402196 DOI: 10.1016/j.anaerobe.2009.01.002
    The aim of this study was to determine the effect of exogenous nitric oxide (NO) on the induction of murine splenic immune response to Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS) in vitro. BALB/c mice were immunized with A. actinomycetemcomitans LPS and a control group was sham-immunized. Spleen cells were obtained, cultured and stimulated with A. actinomycetemcomitans LPS with or without the presence of S-nitroso acetyl-penicillamine (SNAP), a NO donor, and carboxy-PTIO, an NO scavenger. Culture supernatants were assessed for inducible nitric oxide synthase (iNOS) activity, specific IgG subclass levels, and both IFN-gamma and IL-4 levels. The results showed that in A. actinomycetemcomitans LPS-stimulated cells, SNAP enhances iNOS activity but inhibits the levels of specific IgG2a and IFN-gamma suggesting a Th1 response. The effect of SNAP on these immune parameters was ablated by carboxy-PTIO. These results suggest that exogenous NO may suppress the Th1-like immune response of A. actinomycetemcomitans LPS-stimulated murine spleen cells.
    Matched MeSH terms: Cells, Cultured
  17. In vitro biocompatibility of chitosan porous skin regenerating templates (PSRTs) using primary human skin keratinocytes
    Lim CK, Yaacob NS, Ismail Z, Halim AS
    Toxicol In Vitro, 2010 Apr;24(3):721-7.
    PMID: 20079826 DOI: 10.1016/j.tiv.2010.01.006
    Biopolymer chitosan (beta-1,4-d-glucosamine) comprises the copolymer mixture of N-acetylglucosamine and glucosamine. The natural biocompatibility and biodegradability of chitosan have recently highlighted its potential use for applications in wound management. Chemical and physical modifications of chitosan influence its biocompatibility and biodegradability, but it is unknown as to what degree. Hence, the biocompatibility of the chitosan porous skin regenerating templates (PSRT 82, 87 and 108) was determined using an in vitro toxicology model at the cellular and molecular level on primary normal human epidermal keratinocytes (pNHEK). Cytocompatibility was accessed by using a 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl tetrazolium bromide (MTT) assay from 24 to 72h. To assess the genotoxicity of the PSRTs, DNA damage to the pNHEK was evaluated by using the Comet assay following direct contact with the various PSRTs. Furthermore, the skin pro-inflammatory cytokines TNF-alpha and IL-8 were examined to evaluate the tendency of the PSRTs to provoke inflammatory responses. All PSRTs were found to be cytocompatible, but only PSRT 108 was capable of stimulating cell proliferation. While all of the PSRTs showed some DNA damage, PSRT 108 showed the least DNA damage followed by PSRT 87 and 82. PSRT 87 and 82 induced a higher secretion of TNF-alpha and IL-8 in the pNHEK cultures than did PSRT 108. Hence, based on our experiments, PSRT 108 is the most biocompatible wound dressing of the three tested.
    Matched MeSH terms: Cells, Cultured
  18. Organ- and endotheliotropism of Nipah virus infections in vivo and in vitro
    Maisner A, Neufeld J, Weingartl H
    Thromb. Haemost., 2009 Dec;102(6):1014-23.
    PMID: 19967130 DOI: 10.1160/TH09-05-0310
    Nipah virus (NiV) is a highly pathogenic paramyxovirus that was first isolated in 1999 during an outbreak in Malaysia. In contrast to other paramyxoviruses NiV infects many mammalian species. Because of its zoonotic potential, the high pathogenicity and the lack of therapeutic treatment, NiV was classified as a biosafety level 4 pathogen. In humans NiV causes a severe acute encephalitis whereas in some animal hosts respiratory symptoms are predominantly observed. Despite the differences in the clinical outcome, microvascular endothelial cell damage predominantly underlies the pathological changes in NiV infections in all susceptible host species. NiV generally induces a pronounced vasculitis which is primarily characterised by endothelial cell necrosis and inflammatory cell infiltration. For future developments of specific antiviral therapies or vaccines, a detailed understanding of the molecular basis of NiV pathogenesis is required. This article reviews the current knowledge about natural and experimental infections in different mammals, focusing on the main organ and cell tropism in vivo, and summarises some recent studies in cell culture on the role of ephrin-B2 and -B3 receptors in NiV infection of endothelial cells.
    Matched MeSH terms: Cells, Cultured
  19. The cag PAI is intact and functional but HP0521 varies significantly in Helicobacter pylori isolates from Malaysia and Singapore
    Schmidt HM, Andres S, Nilsson C, Kovach Z, Kaakoush NO, Engstrand L, et al.
    Eur J Clin Microbiol Infect Dis, 2010 Apr;29(4):439-51.
    PMID: 20157752 DOI: 10.1007/s10096-010-0881-7
    Helicobacter pylori-related disease is at least partially attributable to the genotype of the infecting strain, particularly the presence of specific virulence factors. We investigated the prevalence of a novel combination of H. pylori virulence factors, including the cag pathogenicity island (PAI), and their association with severe disease in isolates from the three major ethnicities in Malaysia and Singapore, and evaluated whether the cag PAI was intact and functional in vitro. Polymerase chain reaction (PCR) was used to detect dupA, cagA, cagE, cagT, cagL and babA, and to type vacA, the EPIYA motifs, HP0521 alleles and oipA ON status in 159 H. pylori clinical isolates. Twenty-two strains were investigated for IL-8 induction and CagA translocation in vitro. The prevalence of cagA, cagE, cagL, cagT, babA, oipA ON and vacA s1 and i1 was >85%, irrespective of the disease state or ethnicity. The prevalence of dupA and the predominant HP0521 allele and EPIYA motif varied significantly with ethnicity (p < 0.05). A high prevalence of an intact cag PAI was found in all ethnic groups; however, no association was observed between any virulence factor and disease state. The novel association between the HP0521 alleles, EPIYA motifs and host ethnicity indicates that further studies to determine the function of this gene are important.
    Matched MeSH terms: Cells, Cultured
  20. Is vitamin E toxic to neuron cells?
    Then SM, Mazlan M, Mat Top G, Wan Ngah WZ
    Cell Mol Neurobiol, 2009 Jun;29(4):485-96.
    PMID: 19172392 DOI: 10.1007/s10571-008-9340-8
    Besides acting as potent free radical scavengers, tocopherols and tocotrienols have been known to have non-antioxidant properties such as the involvement of alpha-tocopherol (alphaT) in PKC pathway and the anti-cancer properties of gamma-tocotrienol (gammaT3). This study aims to elucidate whether protective effects shown by alphaT and gammaT3 in H(2)O(2)-induced neuron cultures have anti-apoptotic or pro-apoptotic tendency toward the initiation of neuronal apoptosis. H(2)O(2) is used to induce apoptosis in primary cerebellar neuron cultures which is attenuated by pretreatment of alphaT or gammaT3 at concentrations < or =10 microM. Similar to our previous work, gammaT3 was found to be neurotoxic at concentrations > or =100 microM, whereas alphaT showed no neurotoxicity. Cellular uptake of gammaT3 was higher than that of alphaT. Treating cells simultaneously with either gammaT3 or alphaT and with then H(2)O(2) led to higher expression of Bax and Bcl-2 than in neurons exposed to H(2)O(2) alone. Analysis of Bcl-2/Bax ratio as 'survival index' showed that both pretreatment of gammaT3 and alphaT followed by H(2)O(2) increase the 'survival index' of Bcl-2/Bax ratio compared to H(2)O(2)-treated cells, while treatment of gammaT3 alone decrease the ratio compared to unchanged Bcl2/Bax ratio of similar treatment with alphaT alone. Similar treatment of gammaT3 decreased p53 expression and activates p38 MAPK phosphorylation, whereas alphaT did not alter its expression compared to H(2)O(2)-treated cells. Treating neurons with only gammaT3 or alphaT increased the expression of Bax, Bcl-2, p53, and p38 MAPK compared to control with gammaT3 exerting stronger expression for proteins involved than alphaT. In conclusion, low doses of gammaT3 and alphaT confer neuroprotection to H(2)O(2)-treated neurons via their antioxidant mechanism but gammaT3 has stronger pro-apoptosis tendency than alphaT by activating molecules involved in the neuronal apoptotic pathway in the absence of H(2)O(2).
    Matched MeSH terms: Cells, Cultured
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