Displaying publications 21 - 40 of 248 in total

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  1. Khan KM, Naz F, Taha M, Khan A, Perveen S, Choudhary MI, et al.
    Eur J Med Chem, 2014 Mar 3;74:314-23.
    PMID: 24486414 DOI: 10.1016/j.ejmech.2014.01.001
    Thiourea derivatives (1-38) were synthesized and evaluated for their urease inhibition potential. The synthetic compounds showed a varying degree of in vitro urease inhibition with IC50 values 5.53 ± 0.02-91.50 ± 0.08 μM, most of which are superior to the standard thiourea (IC₅₀ = 21.00 ± 0.11 μM). In order to ensure the mode of inhibition of these compounds, the kinetic study of the most active compounds has been carried out. Most of these inhibitors were found to be mixed-type of inhibitors, except compounds 13 and 30 which were competitive, while compound 19 was identified as non-competitive inhibitor with Ki values between 8.6 and 19.29 μM.
    Matched MeSH terms: In Vitro Techniques
  2. Low PT, Lai MI, Ngai SC, Abdullah S
    Gene, 2014 Jan 1;533(1):451-5.
    PMID: 24120896 DOI: 10.1016/j.gene.2013.09.075
    Current viral gene delivery vectors for gene therapy are inefficient due to short-lived transgene expression attributed to the cytosine-phosphate-guanine (CpG) motifs in the transgene. Here we assessed the effects of CpG motif reduction in lentiviral (LV) gene delivery context on the level and duration of reporter gene expression in Chinese Hamster Ovary (CHO) cells, Human Immortalized Myelogenous Leukemia (K562) cells and hematopoietic stem cells (HSCs). The cells were transduced with LV carrying Zero-CpG green fluorescent protein (ZGFP) reporter gene, LV/CMV/ZGFP. The GFP expression was compared to its non CpG-depleted GFP reporter gene LV (LV/CMV/GFP) counterpart. The LV/CMV/ZGFP exhibited prolonged transgene expression in CHO cells and HSCs up to 10 days and 14 days, in the respective cells. This effect was not seen in the transduced K562 cells, which may be due to the DNA hypomethylation status of the cancer cell line. Transgene copy number analysis verified that the GFP expression was not from pseudo-transduction and the transgene remained in the genome of the cells throughout the period of the study. The modest positive effects from the LV/CMV/ZGFP suggest that the reduction of CpG in the LV construct was not substantial to generate higher and more prolonged transgene expression.
    Matched MeSH terms: In Vitro Techniques
  3. Zaman WS, Makpol S, Sathapan S, Chua KH
    J Tissue Eng Regen Med, 2014 Jan;8(1):67-76.
    PMID: 22552847 DOI: 10.1002/term.1501
    In the field of cell-based therapy and regenerative medicine, clinical application is the ultimate goal. However, one major concern is: does in vitro manipulation during culture expansion increases tumourigenicity risk on the prepared cells? Therefore, the aim of this study was to investigate the effect of long-term in vitro expansion on human adipose-derived stem cells (ASCs). The ASCs were harvested from lipo-aspirate samples and cultured until passage 20 (P20), using standard culture procedures. ASCs at P5, P10, P15 and P20 were analysed for morphological changes, DNA damage (Comet assay), tumour suppressor gene expression level (quantitative PCR), p53 mutation, telomerase activity, telomere length determination and in vivo tumourigenicity test. Our data showed that ASCs lost their fibroblastic feature in long-term culture. The population doubling time of ASCs increased with long-term culture especially at P15 and P20. There was an increase in DNA damage at later passages (P15 and P20). No significant changes were observed in both p53 and p21 genes expression throughout the long-term culture. There was also no p53 mutation detected and no significant changes were recorded in the relative telomerase activity (RTA) and mean telomere length (TRF) in ASCs at all passages. In vivo implantation of ASCs at P15 and P20 into the nude mice did not result in tumour formation after 4 months. The data showed that ASCs have low risk of tumourigenicity up to P20, with a total population doubling of 42 times. This indicates that adipose tissue should be a safe source of stem cells for cell-based therapy.
    Matched MeSH terms: In Vitro Techniques
  4. Tang SY, Shridharan P, Sivakumar M
    Ultrason Sonochem, 2013 Jan;20(1):485-97.
    PMID: 22633626 DOI: 10.1016/j.ultsonch.2012.04.005
    In the present investigation, the operating efficiency of a bench-top air-driven microfluidizer has been compared to that of a bench-top high power ultrasound horn in the production of pharmaceutical grade nanoemulsions using aspirin as a model drug. The influence of important process variables as well as the pre-homogenization and drug loading on the resultant mean droplet diameter and size distribution of emulsion droplets was studied in an oil-in-water nanoemulsion incorporated with a model drug aspirin. Results obtained show that both the emulsification methods were capable of producing very fine nanoemulsions containing aspirin with the minimum droplet size ranging from 150 to 170 nm. In case of using the microfluidizer, it has been observed that the size of the emulsion droplets obtained was almost independent of the applied microfluidization pressure (200-600 bar) and the number of passes (up to 10 passes) while the pre-homogenization and drug loading had a marginal effect in increasing the droplet size. Whereas, in the case of ultrasound emulsification, the droplet size was generally decreased with an increase in sonication amplitude (50-70%) and period of sonication but the resultant emulsion was found to be dependent on the pre-homogenization and drug loading. The STEM microscopic observations illustrated that the optimized formulations obtained using ultrasound cavitation technique are comparable to microfluidized emulsions. These comparative results demonstrated that ultrasound cavitation is a relatively energy-efficient yet promising method of pharmaceutical nanoemulsions as compared to microfluidizer although the means used to generate the nanoemulsions are different.
    Matched MeSH terms: In Vitro Techniques
  5. Raouf AA, Samsudin AR, Al-Joudi FS, Shamsuria O
    Med J Malaysia, 2004 May;59 Suppl B:101-2.
    PMID: 15468838
    The human fibroblast MRC-5 cells incubated with PHB granules (TM) added at a final concentration of 4 mg/ml showed a time-course pattern of survival. The percentages of dead cells obtained were at the rate of 3.8% after 7 days, respectively. When the MRC-5 cells grown in different material, using the test concentration of 4 mg/ml PCM, they were found to show a similar time-course increasing pattern of death as that obtained with PHB. However, the death was noted in the cells incubated for 7 days, the death rates obtained was 40.54% respectively.
    Matched MeSH terms: In Vitro Techniques
  6. Omar NA, Praveena SM, Aris AZ, Hashim Z
    Food Chem, 2015 Dec 1;188:46-50.
    PMID: 26041162 DOI: 10.1016/j.foodchem.2015.04.087
    Little is known about the bioavailability of heavy metal contamination and its health risks after rice ingestion. This study aimed to determine bioavailability of heavy metal (As, Cd, Cu, Cr, Co, Al, Fe, Zn and Pb) concentrations in cooked rice and human Health Risk Assessment (HRA). The results found Zn was the highest (4.3±0.1 mg/kg), whereas As showed the lowest (0.015±0.001 mg/kg) bioavailability of heavy metal concentration in 22 varieties of cooked rice. For single heavy metal exposure, no potential of non carcinogenic health risks was found, while carcinogenic health risks were found only for As. Combined heavy metal exposures found that total Hazard Quotient (HQtotal) values for adult were higher than the acceptable range (HQTotal<1), whereas total Lifetime Cancer Risk (LCRTotal) values were higher than the acceptable range (LCRTotal values >1×10(-4)) for both adult and children. This study is done to understand that the inclusion of bioavailability heavy metal into HRA produces a more realistic estimation of human heavy metal exposure.
    Matched MeSH terms: In Vitro Techniques
  7. Brahmachari G, Choo C, Ambure P, Roy K
    Bioorg Med Chem, 2015 Aug 01;23(15):4567-4575.
    PMID: 26105711 DOI: 10.1016/j.bmc.2015.06.005
    A series of densely functionalized piperidine (FP) scaffolds was synthesized following a diastereoselective one-pot multicomponent protocol under eco-friendly conditions. The FPs were evaluated in vitro for their acetylcholinesterase (AChE) inhibitory activity, and in silico studies for all the target compounds were carried out using pharmacophore mapping, molecular docking and quantitative structure-activity relationship (QSAR) analysis in order to understand the structural features required for interaction with the AChE enzyme and the key active site residues involved in the intermolecular interactions. Halogenation, nitration or 3,4-methylenedixoxy-substitution at the phenyl ring attached to the 2- and 6-positions of 1,2,5,6-tetrahydropyridine nucleus in compounds 14-17, 19, 20, 24 and 26 greatly enhanced the AChE inhibitory activity. The docking analysis demonstrated that the inhibitors are well-fitted in the active sites. The in silico studies enlighten the future course of studies in modifying the scaffolds for better therapeutic efficacy against the deadly Alzheimer's disease.
    Matched MeSH terms: In Vitro Techniques
  8. Goh TB, Koh RY, Yam MF, Azhar ME, Mordi MN, Mansor SM
    Food Chem, 2015 Sep 15;183:208-16.
    PMID: 25863630 DOI: 10.1016/j.foodchem.2015.03.044
    Various 6-methoxytetrahydro-β-carboline derivatives, namely BEN (6-methoxy-1-phenyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole), ANI (6-methoxy-1-(4-methoxyphenyl)-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole), ACE (6-methoxy-1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole) and VAN (2-methoxy-4-(6-methoxy-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indol-1-l)phenol), were prepared via the Maillard reaction using food flavours and 5-methoxytryptamine in aqueous medium and were investigated for their in vitro antioxidant and cytotoxicity properties. These derivatives were found to exhibit moderate antioxidant properties, based on a combination of DPPH, ABTS and FRAP assays. The results suggested that the Maillard reaction could be used to generate β-carboline antioxidants. It was beneficial that VAN showed the highest antioxidant activity but the least cytotoxic activities on non-tumourous cell lines of NIH/3T3, CCD18-Co and B98-5 using MTT assay. ACE, ANI and BEN showed mild toxicity at effective antioxidative concentrations derived from DPPH and ABTS assays. Furthermore, they are safer compared to 5-fluorouracil, cisplatin and betulinic acid on NIH/3T3, CCD18-Co and B98-5 cells. In conclusion, the antioxidant and cytotoxicity properties of 6-methoxytetrahydro-β-carbolines were demonstrated for the first time.
    Matched MeSH terms: In Vitro Techniques
  9. Tay ST, Rohani MY, Ho TM, Devi S
    PMID: 12971561
    Using cultured mouse fibroblast L929 cells, this study demonstrated the hemolytic and cytotoxic activities and induction of apoptosis in cells infected with Orientia tsutsugamushi. Low levels of hemolytic activity were detected using heavily infected cells. No hemolysin or cytotoxin were detected in the infected culture fluid regardless of the pathogenicity of the O. tsutsugamushi strains in mice. Using propidium iodide uptake assay, acridine orange/ethidium bromide staining and terminal deoxynucleotide transferase-mediated dUTP-digoxigenin nick-end labeling assay, apoptosis was observed in L929 cells infected with Karp and Gilliam strains.
    Matched MeSH terms: In Vitro Techniques
  10. Ridzwan BH, Kaswandi MA, Azman Y, Fuad M
    Gen. Pharmacol., 1995 Nov;26(7):1539-43.
    PMID: 8690242
    1. Three species of sea cucumbers found in the Sabah coastal areas were screened for the presence of antibacterial activity using three methods of extraction. Tests were conducted in vitro using the agar absorption method. 2. Both the lipid extract and the methanol-solvent extract from Holothuria atra, Holothuria scabra and Bohadshia argus were found to show no antibacterial activity. 3. Phosphate-buffered saline (PBS) from H. atra and B. argus, however, inhibited the growth of all gram-positive and gram-negative bacteria. 4. Comparisons were also made between extracts from the outer layer of H. atra and its inner part, and it was found that the extract from the outer layer showed less bacterial growth inhibition property. 5. The bacterial growth inhibition property of the PBS extract from H. atra, however, is dependent on the extract's concentration. Bacterial growth inhibition was apparent after 48 hr incubation.
    Matched MeSH terms: In Vitro Techniques
  11. Ng KH, Bradley DA, Looi LM, Mahmood CS, Wood AK
    Appl Radiat Isot, 1993 Mar;44(3):511-6.
    PMID: 8472024
    Multi-elemental quantitative analyses of 15 paired samples of normal and malignant human breast tissue by instrumental neutron activation analysis are reported. The elements, Al, Br, Ca, Cl, Co, Cs, Fe, K, Na, Rb, Zn were detected. Significantly elevated concentration levels were found for Al, Br, Ca, Cl, Cs, K, Na, Zn in malignant compared to normal tissue. Although the role of elemental composition in breast cancer is unclear, this finding may be of importance as another parameter for differentiating normal from malignant tissue.
    Matched MeSH terms: In Vitro Techniques
  12. Ismail G, Razak N, Mohamed R, Embi N, Omar O
    Microbiol. Immunol., 1988;32(7):645-52.
    PMID: 3193910
    The effect of human normal serum (HNS) on Pseudomonas pseudomallei was determined. It is apparent from our data that the organism is resistant to the normal serum bactericidal mechanism. Ancillary experiments to confirm this serum-resistant property of P. pseudomallei were done by examining the effects of growth phase conditions of the bacteria (i.e., logarithmic and stationary phases) and different buffered systems used as diluent in our bactericidal assay. Results obtained showed similar degree of resistance to serum bactericidal killing by 5 strains of the organisms tested. The possible survival advantage of serum-resistance property to P. pseudomallei as bacterial pathogens known to invade the blood stream is discussed.
    Matched MeSH terms: In Vitro Techniques
  13. Orihel TC
    J Parasitol, 1966 Feb;52(1):162-5.
    PMID: 5910449
    Matched MeSH terms: In Vitro Techniques
  14. Surjit Singh CK, Lim HP, Tey BT, Chan ES
    Carbohydr Polym, 2021 Jan 01;251:117110.
    PMID: 33142647 DOI: 10.1016/j.carbpol.2020.117110
    The commercial application of liquid-state Pickering emulsions in food systems remains a major challenge. In this study, we developed a spray-dried Pickering emulsion powder using chitosan as a Pickering emulsifier and alginate as a coating material. The functionality of the powder was evaluated in terms of its oxidative stability, pH-responsiveness, mucoadhesivity, and lipid digestibility. The Pickering emulsion powder was oxidatively more stable than the conventional emulsion powder stabilized by gum Arabic. The powder exhibited pH-responsiveness, whereby it remained intact in acidic pH, but dissolved to release the emulsion in 'Pickering form' at near-neutral pH. The Pickering emulsion powder was also mucoadhesive and could be digested by lipase in a controlled manner. These findings suggested that the multi-functional Pickering emulsion powder could be a potential delivery system for applications in the food industry.
    Matched MeSH terms: In Vitro Techniques
  15. Singh RB
    Med J Malaya, 1966 Mar;20(3):215-20.
    PMID: 4223129
    Matched MeSH terms: In Vitro Techniques
  16. Chong YH, Beng CG
    Med J Malaya, 1965 Sep;20(1):49-50.
    PMID: 4221413
    Matched MeSH terms: In Vitro Techniques
  17. Saber SEDM, Ahmed MHM, Obeid M, Ahmed HMA
    Int Endod J, 2019 Mar;52(3):267-278.
    PMID: 30225932 DOI: 10.1111/iej.13016
    AIM: To investigate the number of roots and root canal configurations using two coding systems and the root canal diverging and merging levels in extracted maxillary premolars in an Egyptian subpopulation using cone beam computed tomography (CBCT).

    METHODOLOGY: A total of 700 maxillary premolars were examined using CBCT in an Egyptian subpopulation. The number of roots was identified, and root canal configurations were classified according to Vertucci's classification and a new system for classifying root and canal morphology. In addition, the position where roots bifurcated and the levels where canals merged or diverged were identified. Fisher's exact test and independent t-test were used for statistical analysis, and the level of significance was set at 0.05 (P = 0.05).

    RESULTS: More than half of maxillary first premolars were double-rooted, and the majority of maxillary second premolars were single-rooted (P 

    Matched MeSH terms: In Vitro Techniques
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