Displaying publications 61 - 80 of 248 in total

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  1. Zainuddin A, Makpol S, Chua KH, Abdul Rahim N, Yusof YA, Ngah WZ
    Med J Malaysia, 2008 Jul;63 Suppl A:73-4.
    PMID: 19024990
    Validation of housekeeping gene is important for accurate quantitation of RNA in real time RT-PCR technique. The purpose of this study was to determine the validity of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as a housekeeping gene for quantitative real time RT-PCR assessment in human skin fibroblast senescent model. The cells were divided into different treatment groups; young (passage 4), senescent (passage 30), treatment with H2O2 and treatment with A-tocotrienol prior to H2O2 treatment. Our results showed that the expression level of GAPDH was constant with different treatment groups. Therefore, we concluded that GAPDH was suitable to be used as housekeeping gene in human skin fibroblast senescent model.
    Matched MeSH terms: In Vitro Techniques
  2. Mok PL, Cheong SK, Leong CF
    Malays J Pathol, 2008 Jun;30(1):11-9.
    PMID: 19108406 MyJurnal
    Mesenchymal stem cells are pluripotent progenitors that could be found in human bone marrow. Mesenchymal stem cells are capable of renewing themselves without differentiation in long-term culture. These cells also have low immunogenicity and can suppress alloreactive T cell responses. In the current study, mesenchymal stem cells isolated and propagated previously from the bone marrow of a megaloblastic anaemia patient were tested for their capabilities to differentiate into adipocytes, chondrocytes and osteoblasts in vitro. The differentiated cells were determined by Oil Red O, Alcian Blue-PAS and Alizarin Red S staining, and reverse transcriptase-polymerase chain reaction to determine the expression of mRNA specific for adipogenesis, chondrogenesis and osteogenesis. The results showed that the fibroblast-like cells were capable of differentiating into adipocytes, chondrocytes and osteoblasts upon chemical induction. The adipocytes, chondrocytes and osteoblasts were stained positively to Oil Red O, Alcian Blue-PAS and Alizarin Red S respectively. The differentiated cells were also found to express mRNA specific for adipogenesis ('peroxisome proliferation-activated receptor gamma2' and lipoprotein lipase), chondrogenesis (collagen type II) and osteogenesis (osteocalcin, osteopontin and alkaline phosphatase). In conclusion, this research has successfully isolated fibroblast-like cells from human bone marrow and these cells demonstrated morphological, cytochemical and immunochemical characteristics similar to mesenchymal stem cells. These cells maintain their proliferative properties and could be differentiated into the mesoderm lineage. The success of this study is vital because mesenchymal stem cells can be used in cellular therapy to regenerate or replace damaged tissues, or as a vehicle for therapeutic gene delivery in the future.
    Matched MeSH terms: In Vitro Techniques
  3. Simat SF, Chua KH, Abdul Rahman H, Tan AE, Tan GC
    Med J Malaysia, 2008 Jul;63 Suppl A:53-4.
    PMID: 19024980
    The aim of the study is to evaluate the stemness gene expression of cultured human amniotic epithelial cells (HAECs) in serial passages. HAECs obtained from human term placentae were cultured in F12:DMEM(1:1) + 10% FBS +10ng/ml EGF in serial passages (P0, P1, P2 and P4). Quantitative RT-PCR was used to assess the gene expression analysis. The results showed that cultured HAECs expressed and downregulated the stemness genes expression for Oct-4, Sox-2, Nanog3, FGF4, Rex-1, FZD-9, BST-1 ABCG2. However, vimentin and nestin gene expression were upregulated. The results suggested that cultured HAECs may have pluripotent and multipotent properties.
    Matched MeSH terms: In Vitro Techniques
  4. Munirah S, Samsudin OC, Chen HC, Salmah SH, Aminuddin BS, Ruszymah BH
    Med J Malaysia, 2008 Jul;63 Suppl A:35-6.
    PMID: 19024971
    Chondrocytes were isolated from articular cartilage biopsy and were cultivated in vitro. Approximately 30 million of cultured chondrocytes per ml were incorporated with autologous plasma-derived fibrin to form three-dimensional construct. Full-thickness punch hole defects were created in lateral and medial femoral condyles. The defects were implanted either with the autologous 'chondrocytes-fibrin' construct (ACFC), autologous chondrocytes (ACI) or fibrin blank (AF). Sheep were euthanized after 12 weeks. The gross morphology of all defects treated with ACFC implantation, ACI and AF exhibited median scores which correspond to a nearly normal appearance according to the International Cartilage Repair Society (ICRS) classification. ACFC significantly enhanced cartilage repair compared to ACI and AF in accordance with the modified O'Driscoll histological scoring scale. The relative sulphated glycosaminoglycans content (%) was significantly higher (p < 0.05) in ACFC when compared to control groups; ACI vs. fibrin only vs. untreated (blank). Results showed that ACFC implantation exhibited superior cartilage-like tissue regeneration compared to ACI. If the result is applicable to the human, it possibly will improve the existing treatment approaches for cartilage restoration in orthopaedic surgery.
    Matched MeSH terms: In Vitro Techniques
  5. Zaman WS, Makpol S, Santhapan S, Chua KH
    Med J Malaysia, 2008 Jul;63 Suppl A:61-2.
    PMID: 19024984
    It is crucial to know whether stem cells retain its stemnness properties after advance in vitro manipulation. The objective of this study was to investigate the stemness gene expression of human adipose tissue derived stem cells (ADSCs) in long-term culture using quantitative RT-PCR technique. Our data showed that the expression level of Sox-2, Rex-1, FGF-4, Nanog, Nestin, BST-1, FZD-9 and Oct-4 were decreased gradually in long-term culture. This could mean that the ability of ADSCs to differentiate into other cell lineages reduce after extensive culture.
    Matched MeSH terms: In Vitro Techniques
  6. Ooi YY, Ramasamy R, Vidyadaran S
    Med J Malaysia, 2008 Jul;63 Suppl A:65-6.
    PMID: 19024986
    Classically, MSC are identified by a CD45-CD106+ phenotype. In this study, we found that mouse MSC achieve this characteristic phenotype only at later passages. With increasing passages, CD45 (hematopoietic marker) expression shifts to negativity, whereas CD106 (vascular cell adhesion molecule-1) expression becomes increasingly positive. These results demonstrate that MSC cells cultured from mouse bone marrow acquire a classical MSC immunophenotype (CD45-CD106+) in later passages.
    Matched MeSH terms: In Vitro Techniques
  7. Noordin L, San GT, Singh HJ, Othman MS, Hafizah W
    Eur J Obstet Gynecol Reprod Biol, 2008 Jan;136(1):67-73.
    PMID: 18079036
    To ascertain the embryotoxicity of peritoneal fluid from infertile women with endometriosis (PF-E), on mouse embryos in culture and to examine the effect of pyruvate in the culture medium on PF-E induced embryotoxicity.
    Matched MeSH terms: In Vitro Techniques
  8. Shamsuria O, Fadilah AS, Asiah AB, Rodiah MR, Suzina AH, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:174-5.
    PMID: 15468874
    The aim of this study was to evaluate the in vitro cytotoxicity of biomaterials; Hydroxyapatite (HA), Natural coral (NC) and Polyhydroxybutarate (PHB). Three different materials used in this study; HA (Ca10(PO4)6(OH)2), NC (CaCO3) and PHB (Polymer) were locally produced by the groups of researcher from Universiti Sains Malaysia. The materials were separately extracted in the complete culture medium (100mg/ml) for 72h and introduced to the osteoblast cells CRL-1543. The viability of osteoblast CRL-1543 cultivated with these extraction materials after 72h incubation period was compared to negative control with neutral red assay by using spectrophotometer at 540nm. The results showed the non-cytotoxicity of the materials. After 72h of incubation period, HA showed 123% viable cells, NC was 99.43% and PHB was 176.75%. In this study, cytotoxicity test dealt mainly with the substances that leached out from the biomaterial. The results obtained showed that the materials were not toxic and also promoted cells growth in the sense of biofunctionality.
    Matched MeSH terms: In Vitro Techniques
  9. Shaari R, Samsudin AR
    Med J Malaysia, 2004 May;59 Suppl B:109-10.
    PMID: 15468842
    The present in vitro evaluation indicated that the value added hydroxyapatite (HA) was more toxic than pure HA but the toxicity of value added HA was slight compared to the positive control. In this testing, the conclusion can be made that value added HA is less biocompatible than commercialized pure HA. This toxicity may be caused by both the particle size and degradation (leaching). Further studies should be carried out to determine whether there is particle size effect or leaching effect when using powder as compared to the block materials. The in vivo evaluation should be done to assess the reaction to this value added HA as compared to the pure HA.
    Matched MeSH terms: In Vitro Techniques
  10. Ang HH, Cheang HS, Mak JW
    Chemotherapy, 2005 Oct;51(6):377-80.
    PMID: 16227695
    Exposure of Plasmodium falciparum to increasing sublethal drug concentrations followed by drug treatment led to the development of many resistant parasites. Therefore, the susceptibility of these clones to the type II antifolate drugs, cycloguanil and pyrimethamine, before and after subculturing them in vitro for a period of 3 years, was studied.
    Matched MeSH terms: In Vitro Techniques
  11. Liew KL, Jee JM, Yap I, Yong PV
    PLoS One, 2016;11(4):e0153356.
    PMID: 27054608 DOI: 10.1371/journal.pone.0153356
    Cryptococcus neoformans is an encapsulated basidiomycetous yeast commonly associated with pigeon droppings and soil. The opportunistic pathogen infects humans through the respiratory system and the metabolic implications of C. neoformans infection have yet to be explored. Studying the metabolic profile associated with the infection could lead to the identification of important metabolites associated with pulmonary infection. Therefore, the aim of the study was to simulate cryptococcal infection at the primary site of infection, the lungs, and to identify the metabolic profile and important metabolites associated with the infection at low and high multiplicity of infections (MOI). The culture supernatant of lung epithelial cells infected with C. neoformans at MOI of 10 and 100 over a period of 18 hours were analysed using gas chromatography mass spectrometry. The metabolic profiles obtained were further analysed using multivariate analysis and the pathway analysis tool, MetaboAnalyst 2.0. Based on the results from the multivariate analyses, ten metabolites were selected as the discriminatory metabolites that were important in both the infection conditions. The pathways affected during early C. neoformans infection of lung epithelial cells were mainly the central carbon metabolism and biosynthesis of amino acids. Infection at a higher MOI led to a perturbance in the β-alanine metabolism and an increase in the secretion of pantothenic acid into the growth media. Pantothenic acid production during yeast infection has not been documented and the β-alanine metabolism as well as the pantothenate and CoA biosynthesis pathways may represent underlying metabolic pathways associated with disease progression. Our study suggested that β-alanine metabolism and the pantothenate and CoA biosynthesis pathways might be the important pathways associated with cryptococcal infection.
    Matched MeSH terms: In Vitro Techniques
  12. Fong Yen W, Basri M, Ahmad M, Ismail M
    ScientificWorldJournal, 2015;2015:495271.
    PMID: 25853145 DOI: 10.1155/2015/495271
    Galantamine hydrobromide is formulated in tablets and capsules prescribed through oral delivery for the treatment of Alzheimer's disease. However, oral delivery of drugs can cause severe side effects such as nausea, vomiting, and gastrointestinal disturbance. Transdermal delivery of galantamine hydrobromide could avoid these unwanted side effects. In this work, galantamine hydrobromide was formulated in gel drug reservoir which was then fabricated in the transdermal patch. The in vitro drug release studies revealed that the drug release from the donor chamber to receptor chamber of Franz diffusion cell was affected by the amount of polymer, amount of neutralizer, amount of drug, types of permeation enhancer, and amount of permeation enhancer. Visual observations of the gels showed that all formulated gels are translucent, homogeneous, smooth, and stable. These gels have pH in the suitable range for skin. The gel also showed high drug content uniformity. Hence, this formulation can be further used in the preparation of transdermal patch drug delivery system.
    Matched MeSH terms: In Vitro Techniques
  13. Pertiwi AK, Kwan TK, Gower DB
    J Steroid Biochem Mol Biol, 2002 Aug;81(4-5):363-7.
    PMID: 12361726
    The intracellular movements of pregnenolone in rat testes were investigated. Whole testes were incubated in the presence or absence of pregnenolone (2.5mM) in the medium for 120 min (in some studies 30, 60, and 90 min). The testes were homogenised, subcellular fractions prepared and analysed in quadruplicate for steroid content by gas chromatography-mass spectrometry with selected ion monitoring. Quantification of pregnenolone and 11 of its metabolites, obtained from non-incubated whole testes, provided values for endogenous amounts. Pregnenolone was the only steroid of quantitative importance found initially in the mitochondrial fraction but was subsequently found in the microsomal fraction, where metabolism occurred. Identification and quantification of metabolites indicated that both classical pathways for testosterone production were operating, with the 4-en-3-oxosteroid pathway predominating. By 120 min, virtually all pregnenolone metabolites, including pregnenolone itself, were found in the cytosol, consistent with an overall movement from mitochondria to endoplasmic reticulum to cytosol.
    Matched MeSH terms: In Vitro Techniques
  14. Yapp DT, Yap SY
    J Ethnopharmacol, 2003 Mar;85(1):145-50.
    PMID: 12576213
    Malaria remains a global problem in the light of chloroquine-resistant strains of Plasmodium falciparum. New compounds are needed for the development of novel antimalarial drugs. Seed, leaf, and fruit skin extracts of Lansium domesticum, a common fruit tree in South-East Asia, are used by indigenous tribes in Sabah, Malaysia for treating malaria. The skin and aqueous leaf extracts of the tree were found to reduce parasite populations of the drug sensitive strain (3D7) and the chloroquine-resistant strain (T9) of P. falciparum equally well. The skin extracts were also found to interrupt the lifecycle of the parasite. The data reported here indicate that extracts of L. domesticum are a potential source for compounds with activity towards chloroquine-resistant strains of P. falciparum.
    Matched MeSH terms: In Vitro Techniques
  15. Lim VKE, Halijah MY
    Med J Malaysia, 2001 Sep;56(3):365-9.
    PMID: 11732084
    The in vitro activity of sulperazon (cefoperazone/sulbactam) was tested against 94 ceftazidime-resistant strains of bacteria isolated from mostly seriously ill patients in critical care units. Acinetobacter baumanii, Pseudomonas aeruginosa and Klebsiella pneumoniae made up 80% of the pathogens studied; 90% of the Klebsiella strains were producers of extended-spectrum beta-lactamases (ESBL). The MIC90 of sulperazon for Klebsiella was 12 mg/l (range 1.5-16 mg/l), indicating that this drug may be a useful alternative for the treatment of ceftazidime-resistant, ESBL-producing Klebsiella.
    Matched MeSH terms: In Vitro Techniques
  16. Najib Nik A Rahman N, Furuta T, Kojima S, Takane K, Ali Mohd M
    J Ethnopharmacol, 1999 Mar;64(3):249-54.
    PMID: 10363840
    In vitro and in vivo studies revealed that Malaysian medicinal plants, Piper sarmentosum, Andrographis paniculata and Tinospora crispa produced considerable antimalarial effects. Chloroform extract in vitro did show better effect than the methanol extract. The chloroform extract showed complete parasite growth inhibition as low as 0.05 mg/ml drug dose within 24 h incubation period (Andrographis paniculata) as compared to methanol extract of drug dose of 2.5 mg/ml but under incubation time of 48 h of the same plant spesies. In vivo activity of Andrographis paniculata also demonstrated higher antimalarial effect than other two plant species.
    Matched MeSH terms: In Vitro Techniques
  17. Samud AM, Asmawi MZ, Sharma JN, Yusof AP
    Immunopharmacology, 1999 Sep;43(2-3):311-6.
    PMID: 10596868
    Crinum asiaticum Linn plant is used in Malaysia as a rheumatic remedy and to relieve local pain. In the present study, we examined the anti-inflammatory effects of this plant extract on carrageenan-induced hind paw oedema in mice. C. asiaticum was serially extracted with petroleum ether, followed by chloroform and lastly, methanol. The chloroform and methanol extracts of the plant given orally (50 mg kg-1) caused significant (p < 0.05; n = 7) reduction in paw oedema but the petroleum ether extract did not induce significant effect (p > 0.05) on paw oedema. The methanol extract was then dissolved in water and extracted consecutively with chloroform, ethyl acetate and butanol. The chloroform fraction of methanol extract (CFME) treatment (50 mg kg(-1)) significantly reduced (p < 0.05; n = 7) the acute paw oedema. This may indicate that active anti-inflammatory compounds are present in the CFME. In an attempt to study the mechanism of action of its anti-inflammatory activity, the effects of CFME on BK- and histamine-induced contractions were investigated in isolated rat uterus and guinea-pig ileum preparations, respectively. It was found that CFME caused dose-dependent reduction (p < 0.05; n = 6) of the contractile response induced by BK and shifted the log dose-response curve of histamine to the right. The present findings suggest that C. asiaticum possessed an anti-inflammatory activity as suggested by its use in traditional medicine. The anti-inflammatory activity of this plant could not have been due to its anti-bradykinin activities as CFME non-specifically inhibited BK-induced contraction. It also suggest that CFME may contain compound(s) with anti-histaminic properties. The significance of these findings is discussed.
    Matched MeSH terms: In Vitro Techniques
  18. Kwan TK, Foong SL, Lim YT, Gower DB
    Biochem. Mol. Biol. Int., 1993 Nov;31(4):733-43.
    PMID: 8298502
    Using the rapid gas chromatographic steroid profiling technique, a number of metabolites of pregnenolone have been separated and quantified after incubation of this steroid with adult rat and neonatal porcine testicular homogenates. It was shown that the 5-ene-3 beta-hydroxy- and the 4-en-3-oxosteroid pathways for androgen biosynthesis were operating in both species, although the former pathway appeared to be more important in porcine testis. This tissue was characterised by the formation of several odorous, and pheromonal, 16-androstenes, which were quantitatively more important than the androgens. Three non-steroidal anti-inflammatory drugs (NSAIDS) caused dose-related inhibition of androgen and 16-androstene biosynthesis when co-incubated with pregnenolone. The order of potency was flurbiprofen > indomethacin > > > aspirin. The possibility that the NSAIDS may interfere with cytochrome P-450 is discussed, since several steroid-transforming enzymes, known to be dependent on this cytochrome for their activity, were markedly inhibited.
    Matched MeSH terms: In Vitro Techniques
  19. Akbar A, Sharma JN, Yusof AP, Gan EK
    Int J Tissue React, 1998;20(3):95-100.
    PMID: 9894182
    We studied the effect of indomethacin, a cyclooxygenase inhibitor, on bradykinin-induced responses in the intact and denuded epithelium of the isolated tracheal smooth muscle in guinea pigs. Epithelium removal alone did not alter the responsiveness to bradykinin. Indomethacin (2.8 microM) enhanced the sensitivity to bradykinin of both intact and denuded preparations. This finding suggests that the tracheal epithelial may have no protective effect on the contractile responses induced by bradykinin. This may be due to the presence of high amounts of bradykinin-inactivating enzymes in the tracheal smooth muscle. Indomethacin-medicated potentiation caused by bradykinin in epithelium intact and denuded preparations may be an indication of removal of the bronchodilator prostaglandin biosynthesis. The significance of these findings is discussed.
    Matched MeSH terms: In Vitro Techniques
  20. Yasin RM, Suan KA, Meng CY
    Sex Transm Dis, 1997 May;24(5):257-60.
    PMID: 9153733
    BACKGROUND AND OBJECTIVES: The antimicrobial susceptibility pattern of Neisseria gonorrhoeae varies from one country to another and may also change with time. To monitor these variations and changes, it is desirable to have a method that is simple and reproducible. This study was undertaken to determine the in vitro susceptibility of N. gonorrhoeae to azithromycin and to assess the reliability of results obtained using E-test methodology for determination of the minimum inhibitory concentration (MIC) of azithromycin.

    STUDY DESIGN: The MICs for 135 clinical isolates of N. gonorrhoeae were determined by a modified Kirby-Bauer method recommended by the National Committee for Clinical Laboratory Standards against penicillin, cefuroxime, ceftriaxone, norfloxacin, tetracycline, kanamycin, spectinomycin, and azithromycin. The MIC of azithromycin was determined by both the E-test and agar dilution method. All tests were done simultaneously.

    RESULTS: The MIC of azithromycin to all 135 isolates ranged from 0.078 to 0.25 microgram/ml with the agar dilution method and from 0.016 to 0.50 microgram/ml with the E-test. The MIC50 and MIC90 of azithromycin were 0.064 microgram/ml and 0.125 microgram/ml, respectively, by the agar dilution method, whereas they are slightly higher by the E-test method. Seventy-six of the isolates were beta-lactamase producers and 69 were high-level tetracycline-resistant N. gonorrhoeae. There was no difference in the MIC50 and MIC90 of azithromycin in these groups of isolates. The percentage agreement within the acceptable +/-1 log2 dilution difference between MICs obtained by E-test and those obtained by the agar dilution method was 97.8%.

    CONCLUSIONS: Azithromycin has a very good in vitro antigonococcal activity, and the E-test is a reliable method to determine the MIC of azithromycin against N. gonorrhoeae.

    Matched MeSH terms: In Vitro Techniques
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