Displaying publications 101 - 116 of 116 in total

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  1. Subakir H, Chong YM, Chan YF, Hasan MS, Jamaluddin MFH, Pang YK, et al.
    J Med Microbiol, 2020 Jan;69(1):49-51.
    PMID: 31750812 DOI: 10.1099/jmm.0.001108
    Introduction.Burkholderia pseudomallei (melioidosis) is an important cause of community-acquired pneumonia (CAP) in the tropics. Selective medium is recommended for laboratory diagnosis with non-sterile respiratory samples, while PCR is not routinely used due to variable reported performance. The effectiveness of these diagnostic modalities varies by site.Aim. To compare selective media and real-time PCR (qPCR) with routine media in detecting B. pseudomallei in CAP respiratory samples in a low-incidence setting in Kuala Lumpur, Malaysia.Methodology. Respiratory samples were routinely cultured on blood, chocolate and MacConkey agar (RESP-ROUTINE), and compared to culture on selective Ashdown medium (RESP-SELECTIVE) and qPCR. The gold standard was routine culture of B. pseudomallei from any site (ALL-ROUTINE).Results.B. pseudomallei was detected in 8/204 (3.9 %) samples. Overall sensitivity rates differed (P=0.03) for qPCR (100%), RESP-SELECTIVE (87.5%) and RESP-ROUTINE (50%). There was a trend towards lower median days to positive culture for RESP-SELECTIVE (1 day) compared to RESP-ROUTINE (2 days, P=0.08) and ALL-ROUTINE (2 days, P=0.06). Reagent costs for each additional detection were USD59 for RESP-SELECTIVE and USD354 for PCR.Conclusions. In a low-incidence setting, selective culture of respiratory samples on Ashdown was more sensitive and allowed quicker identification than routine media, at reasonable cost. Blood cultures are critical, confirming four cases missed by routine respiratory culture. Selective medium is useful in early pneumonia (pre-sepsis) and resource-limited settings where blood cultures are infrequently done. Real-time PCR is costly, but highly sensitive and useful for high-risk patients with diabetes, cancer or immunosuppressants, or requiring ventilation or intensive care.
    Matched MeSH terms: Culture Media/chemistry*
  2. Zin NZ, Tasrip NA, Desa MN, Kqueen CY, Zakaria ZA, Hamat RA, et al.
    Trop Biomed, 2011 Dec;28(3):651-60.
    PMID: 22433896 MyJurnal
    This study was to assess the identification and antimicrobial activities of two actinomycete isolates. The two isolates designated as B8 and C2, were isolated from a patch of soil in the peripheral area of Universiti Putra Malaysia by streaking on starch casein agar after standard serial dilution procedures. Their antimicrobial activities were first evaluated against eight clinical laboratory strains namely Bacillus sp., Enterococcus sp., Escherichia coli, Klebsiella sp., Pseudomonas sp., Salmonella sp., Staphylococcus aureus, and Staphylococcus epidermidis by perpendicular streak method on Mueller Hinton and Tryptic Soy agar. In both media, a broad-spectrum antibacterial activity was observed for both isolates, with B8 against all the test bacteria and C2 against five of them (Bacillus sp., E. coli, Pseudomonas sp., S. aureus and S. epidermidis). Re-assessment against E. coli ATCC 25922 and S. aureus ATCC 25923 strains by similar method showed antibacterial activities by isolate B8 against both ATTC strains while C2 only against S. aureus ATCC 25923. Streptomyces griseus ATCC 10137 was included in the later experiment and showed antibacterial activity against both ATCC strains. Subsequently, the two isolates were identified by PCR/sequencing techniques and phylogenetic analysis to be Streptomyces species (>93% homology based on 16S rRNA and rpoB genes). Characterization on cultural characteristic and viable count at different temperatures (37ºC and 28ºC), on different microbiological media (AIA, ISP-2, MHA, NA, PDA and TSA), were performed. More morphological features were observed on ISP-2 for both isolates. A higher growth yield was also observed at 28ºC in all media but in comparing that between the two isolates, isolate B8 outnumbered C2 at all experimental conditions. The observed variation in cultural traits and growth yield indicate unique properties between the two antibiotic-producing isolates.
    Matched MeSH terms: Culture Media/chemistry
  3. Lau YL, Hasan MT, Thiruvengadam G, Idris MM, Init I
    Trop Biomed, 2010 Dec;27(3):525-33.
    PMID: 21399595
    GRA4 of Toxoplasma gondii has been shown to prompt IgG, IgM and IgA responses in previous studies and is thus considered one of the major immunogenic proteins from T. gondii that can be used for both diagnostics purposes and vaccine development. This study seeks to clone and express the GRA4 in Pichia pastoris, which has numerous advantages over other systems for expression of eukaryotic proteins. In order to achieve this, the gene was cloned into the pPICZα A expression vector, which was then incorporated into the P. pastoris genome via insertional integration for expression of the recombinant protein, under the AOX1 promoter. The antigen was expressed along with the prepro sequence of the α-factor of yeast so that it could be excreted out of the P. pastoris cells and obtained from the medium. Upon SDS-PAGE analysis it was found that the recombinant protein was expressed optimally as a 40 kDa protein after 96 hours of induction with 0.75% of methanol. The expressed GRA4 protein showed discrepancy in size with the calculated molecular mass. This may be attributed to the various posttranslational modifications including glycosylation and phosphorylation. Despite the difference in molecular weight, the recombinant protein was able to detect toxoplasmosis in Western blot format. The recombinant GRA4 was expressed with an intact polyhistidine-tag, which could be used for future purification of the antigen.
    Matched MeSH terms: Culture Media/chemistry
  4. Wong PF, Abubakar S
    Cell Mol Biol Lett, 2008;13(3):375-90.
    PMID: 18311544 DOI: 10.2478/s11658-008-0009-6
    Malignant prostate tissues have markedly reduced zinc (Zn(2+)) contents in comparison to non-malignant tissues. In this study, we restored a high intracellular Zn(2+) level to LNCaP prostate cancer cells by culturing the cells in a growth medium supplemented with a supraphysiological concentration of Zn(2+) (10 microg/ml) over 5 weeks. The intracellular Zn(2+) level increased in the Zn(2+)-treated cells, and there was a marked increase in the presence of zincosomes, a Zn(2+)-specific intracellular organelle. The proliferation rate of the Zn(2+)-treated cells was markedly reduced. There was also a significant increase (36.6% +/- 6.4%) in the total tyrosine phosphorylated proteins. Vaccinia H1-related (VHR) phosphatase, zeta chain-associated protein-70 (ZAP-70) kinase and phosphorylated extracellular signal-regulated protein kinase 1 and 2 (p-ERK 1 and 2) were also present in higher abundance. Treatment with TPEN, which chelates Zn(2+), reduced the abundance of VHR phosphatase and ZAP-70 kinase, but increased the abundance of p-ERK 1. However, the TPEN treatment restored the Zn(2+)-treated LNCaP cell proliferation to a rate comparable to that of the non Zn(2+)-treated cells. These results highlight the importance of a high intracellular Zn(2+) content and the VHR/ZAP-70-associated pathways in the modulation of LNCaP prostate cancer cell growth.
    Matched MeSH terms: Culture Media/chemistry
  5. Batumalaie K, Qvist R, Yusof KM, Ismail IS, Sekaran SD
    Clin Exp Med, 2014 May;14(2):185-95.
    PMID: 23584372 DOI: 10.1007/s10238-013-0236-7
    Type 2 diabetes consists of progressive hyperglycemia, insulin resistance, and pancreatic β-cell failure which could result from glucose toxicity, inflammatory cytokines, and oxidative stress. In the present study, we investigate the effect of pretreatment with Gelam honey (Melaleuca spp.) and the individual flavonoid components chrysin, luteolin, and quercetin, on the production of reactive oxygen species (ROS), cell viability, lipid peroxidation, and insulin content in hamster pancreatic cells (HIT-T15 cells), cultured under normal and hyperglycemic conditions. Phenolic extracts from a local Malaysian species of Gelam honey (Melaleuca spp.) were prepared using the standard extraction methods. HIT-T15 cells were cultured in 5 % CO2 and then preincubated with Gelam honey extracts (20, 40, 60, and 80 μg/ml) as well as some of its flavonoid components chrysin, luteolin, and quercetin (20, 40, 60, and 80 μM), prior to stimulation by 20 and 50 mM of glucose. The antioxidative effects were measured in these cultured cells at different concentrations and time point by DCFH-DA assay. Pretreatment of cells with Gelam honey extract or the flavonoid components prior to culturing in 20 or 50 mM glucose showed a significant decrease in the production of ROS, glucose-induced lipid peroxidation, and a significant increase in insulin content and the viability of cells cultured under hyperglycemic condition. Our results show the in vitro antioxidative property of the Gelam honey and the flavonoids on the β-cells from hamsters and its cytoprotective effect against hyperglycemia.
    Matched MeSH terms: Culture Media/chemistry
  6. Sayyed RZ, Wani SJ, Alarfaj AA, Syed A, El-Enshasy HA
    PLoS One, 2020;15(1):e0220095.
    PMID: 31910206 DOI: 10.1371/journal.pone.0220095
    There are numerous reports on poly-β-hydroxybutyrate (PHB) depolymerases produced by various microorganisms isolated from various habitats, however, reports on PHB depolymerase production by an isolate from plastic rich sites scares. Although PHB has attracted commercial significance, the inefficient production and recovery methods, inefficient purification of PHB depolymerase and lack of ample knowledge on PHB degradation by PHB depolymerase have hampered its large scale commercialization. Therefore, to ensure the biodegradability of biopolymers, it becomes imperative to study the purification of the biodegrading enzyme system. We report the production, purification, and characterization of extracellular PHB depolymerase from Stenotrophomonas sp. RZS7 isolated from a dumping yard rich in plastic waste. The isolate produced extracellular PHB depolymerase in the mineral salt medium (MSM) at 30°C during 4 days of incubation under shaking. The enzyme was purified by three methods namely ammonium salt precipitation, column chromatography, and solvent purification. Among these purification methods, the enzyme was best purified by column chromatography on the Octyl-Sepharose CL-4B column giving optimum yield (0.7993 Umg-1mL-1). The molecular weight of purified PHB depolymerase was 40 kDa. Studies on the assessment of biodegradation of PHB in liquid culture medium and under natural soil conditions confirmed PHB biodegradation potential of Stenotrophomonas sp. RZS7. The results obtained in Fourier-Transform Infrared (FTIR) analysis, High-Performance Liquid Chromatography (HPLC) study and Gas Chromatography Mass-Spectrometry (GC-MS) analysis confirmed the biodegradation of PHB in liquid medium by Stenotrophomonas sp. RZS7. Changes in surface morphology of PHB film in soil burial as observed in Field Emission Scanning Electron Microscopy (FESEM) analysis confirmed the biodegradation of PHB under natural soil environment. The isolate was capable of degrading PHB and it resulted in 87.74% biodegradation. A higher rate of degradation under the natural soil condition is the result of the activity of soil microbes that complemented the biodegradation of PHB by Stenotrophomonas sp. RZS7.
    Matched MeSH terms: Culture Media/chemistry
  7. Tay ST, Na SL, Tajuddin TH
    Mycoses, 2008 Nov;51(6):515-9.
    PMID: 18498307 DOI: 10.1111/j.1439-0507.2008.01516.x
    Cryptococcus albidus and C. laurentii were the predominant non-neoformans cryptococci isolated during an environmental sampling study for C. gattii at Klang Valley, Malaysia. Cryptococcus gattii was not isolated from any of the environmental samples. Cryptococcus albidus and C. laurentii were isolated mainly from vegetative samples of Eucalyptus trees and bird droppings. Upon testing on canavanine-glycine-bromothymol blue (CGB) agar, all the C. albidus isolates remained unchanged. Interestingly, a total of 29 (76.3%) C. laurentii isolates formed blue colours on the CGB agar. Sequence analysis of ITS1-5.8rDNA-ITS2 gene sequences (468 bp) of four CGB-blue C. laurentii isolates demonstrated the closest match (99%) with that of C. laurentii CBS 7140. This study demonstrated the diverse environmental niche of C. albidus and C. laurentii in Malaysia.
    Matched MeSH terms: Culture Media/chemistry*
  8. Ling AP, Tan KP, Hussein S
    J Zhejiang Univ Sci B, 2013 Jul;14(7):621-31.
    PMID: 23825148 DOI: 10.1631/jzus.B1200135
    OBJECTIVE: Labisia pumila var. alata, commonly known as 'Kacip Fatimah' or 'Selusuh Fatimah' in Southeast Asia, is traditionally used by members of the Malay community because of its post-partum medicinal properties. Its various pharmaceutical applications cause an excessive harvesting and lead to serious shortage in natural habitat. Thus, this in vitro propagation study investigated the effects of different plant growth regulators (PGRs) on in vitro leaf and stem explants of L. pumila.

    METHODS: The capabilities of callus, shoot, and root formation were evaluated by culturing both explants on Murashige and Skoog (MS) medium supplemented with various PGRs at the concentrations of 0, 1, 3, 5, and 7 mg/L.

    RESULTS: Medium supplemented with 3 mg/L indole-3-butyric acid (IBA) showed the optimal callogenesis from both leaf and stem explants with (72.34 ± 19.55)% and (70.40 ± 14.14)% efficacy, respectively. IBA was also found to be the most efficient PGR for root induction. A total of (50.00 ± 7.07)% and (77.78 ± 16.47)% of root formation were obtained from the in vitro stem and leaf explants after being cultured for (26.5 ± 5.0) and (30.0 ± 8.5) d in the medium supplemented with 1 and 3 mg/L of IBA, respectively. Shoot formation was only observed in stem explant, with the maximum percentage of formation ((100.00 ± 0.00)%) that was obtained in 1 mg/L zeatin after (11.0 ± 2.8) d of culture.

    CONCLUSIONS: Callus, roots, and shoots can be induced from in vitro leaf and stem explants of L. pumila through the manipulation of types and concentrations of PGRs.

    Matched MeSH terms: Culture Media/chemistry
  9. Liew CW, Illias RM, Mahadi NM, Najimudin N
    FEMS Microbiol Lett, 2007 Nov;276(1):114-22.
    PMID: 17937670
    A Na(+)/H(+) antiporter gene was isolated from alkaliphilic Bacillus sp. G1. The full-length sequence of the Na(+)/H(+) antiporter gene was obtained using a genome walking method, and designated as g1-nhaC. An ORF preceded by a promoter-like sequence and a Shine-Dalgarno sequence, and followed by a terminator-like sequence was identified. The deduced amino acid sequence consists of 535 amino acids, and a calculated molecular mass of 57 776 Da. g1-nhaC was subsequently cloned into pET22b(+) and expressed in Escherichia coli BL21 (DE3). Recombinant E. coli harboring the g1-nhaC gene was able to grow in modified L medium at various concentrations of NaCl (0.2-2.0 M) at different pH values. The recombinant bacteria grew well in the medium with concentrations of NaCl as high as 1.75 M at pH 8.0-9.0. Minimal growth was observed at 2.0 M NaCl, pH 8.0-9.0. At pH 10, the recombinant bacteria grew well in a medium with a low concentration of NaCl (0.2 M). These results suggested that the g1-NhaC antiporter from Bacillus sp. G1 plays a role in Na(+) extrusion at lower pH values and in pH homeostasis at pH 10 under Na(+)-limiting conditions.
    Matched MeSH terms: Culture Media/chemistry
  10. Rahman RN, Baharum SN, Salleh AB, Basri M
    J Microbiol, 2006 Dec;44(6):583-90.
    PMID: 17205035
    In this study, an organic solvent tolerant bacterial strain was isolated. This strain was identified as Pseudomonas sp. strain S5, and was shown to degrade BTEX (Benzene, Toluene, Ethyl-Benzene, and Xylene). Strain S5 generates an organic solvent-tolerant lipase in the late logarithmic phase of growth. Maximum lipase production was exhibited when peptone was utilized as the sole nitrogen source. Addition of any of the selected carbon sources to the medium resulted in a significant reduction of enzyme production. Lower lipase generation was noted when an inorganic nitrogen source was used as the sole nitrogen source. This bacterium hydrolyzed all tested triglycerides and the highest levels of production were observed when olive oil was used as a natural triglyceride. Basal medium containing Tween 60 enhanced lipase production to the most significant degree. The absence of magnesium ions (Mg2+) in the basal medium was also shown to stimulate lipase production. Meanwhile, an alkaline earth metal ion, Na+, was found to stimulate the production of S5 lipase.
    Matched MeSH terms: Culture Media/chemistry
  11. Haque N, Kasim NHA, Kassim NLA, Rahman MT
    Cell Prolif, 2017 Aug;50(4).
    PMID: 28682474 DOI: 10.1111/cpr.12354
    OBJECTIVES: Foetal bovine serum (FBS) is often the serum supplement of choice for in vitro human cell culture. This study compares the effect of FBS and autologous human serum (AuHS) supplement in human peripheral blood mononuclear cell (PBMC) culture to prepare secretome.

    MATERIALS AND METHODS: The PBMC (n = 7) were cultured either in RPMI-1640 containing L-glutamine and 50 units/ml Penicillin-Streptomycin (BM) or in BM with either AuHS or FBS. Viability, proliferation and differentiation of PBMC were evaluated. Paracrine factors present in the secretomes (n = 6) were analysed using ProcartaPlex Human Cytokine panel (17 plex). Ingenuity Pathway Analysis (IPA) was performed to predict activation or inhibition of biological functions related to tissue regeneration.

    RESULTS: The viability of PBMC that were cultured with FBS supplement was significantly reduced at 96 h compared to those at 0 and 24 h (P 

    Matched MeSH terms: Culture Media/chemistry
  12. Hasan NAHM, Harith HH, Israf DA, Tham CL
    Mol Biol Rep, 2020 May;47(5):3511-3519.
    PMID: 32279207 DOI: 10.1007/s11033-020-05439-x
    Epithelial-mesenchymal transition (EMT) is one of the mechanisms that contribute to bronchial remodelling which underlie chronic inflammatory airway diseases such as chronic obstructive pulmonary disorder (COPD) and asthma. Bronchial EMT can be triggered by many factors including transforming growth factor β1 (TGFβ1). The majority of studies on TGFβ1-mediated bronchial EMT used BEGM as the culture medium. LHC-9 medium is another alternative available which is more economical but a less common option. Using normal human bronchial epithelial cells (BEAS-2B) cultured in BEGM as a reference, this study aims to validate the induction of EMT by TGFβ1 in cells cultured in LHC-9. Briefly, the cells were maintained in either LHC-9 or BEGM, and induced with TGFβ1 (5, 10 and 20 ng/ml) for 48 h. EMT induction was confirmed by morphological analysis and EMT markers expression by immunoblotting. In both media, cells induced with TGFβ1 displayed spindle-like morphology with a significantly higher radius ratio compared to non-induced cells which displayed a cobblestone morphology. Correspondingly, the expression of the epithelial marker E-cadherin was significantly lower, whereas the mesenchymal marker vimentin expression was significantly higher in induced cells, compared to non-induced cells. By contrast, a slower cell growth rate was observed in LHC-9 compared to that of BEGM. This study demonstrates that neither LHC-9 nor BEGM significantly influence TGFβ1-induced bronchial EMT. However, LHC-9 is less optimal for bronchial epithelial cell growth compared to BEGM. Thus, LHC-9 may be a more cost-effective substitute for BEGM, provided that time is not a factor.
    Matched MeSH terms: Culture Media/chemistry
  13. Thiruvengadam G, Init I, Fong MY, Lau YL
    Trop Biomed, 2011 Dec;28(3):506-13.
    PMID: 22433878 MyJurnal
    Surface antigens are the most abundant proteins found on the surface of the parasite Toxoplasma gondii. Surface antigen 1 (SAG1) and Surface antigen 2 (SAG2) remain the most important and extensively studied surface proteins. These antigens have been identified to play a role in host cell invasion, immune modulation, virulence attenuation. Recombinant SAG1/2 was cloned and expressed in yeast Pichia pastoris. We describe here optimization of critical parameters involved in high yield expression of the recombinant SAG1/2. Our results suggest that recombinant SAG1/2 were best expressed at 30ºC, pH 6 and 1% methanol as the carbon source by X33 Pichia cells. Additional optimizations included the downstream process such as ammonium sulphate precipitation and dialysis. The fusion protein was purified using Ni-NTA purification system with 80% recovery. The purified protein was 100% specific and sensitive in detection of toxoplasmosis.
    Matched MeSH terms: Culture Media/chemistry
  14. Liau LL, Hassan MNFB, Tang YL, Ng MH, Law JX
    Int J Mol Sci, 2021 Jan 28;22(3).
    PMID: 33525349 DOI: 10.3390/ijms22031269
    Osteoarthritis (OA) is a degenerative joint disease that affects a lot of people worldwide. Current treatment for OA mainly focuses on halting or slowing down the disease progress and to improve the patient's quality of life and functionality. Autologous chondrocyte implantation (ACI) is a new treatment modality with the potential to promote regeneration of worn cartilage. Traditionally, foetal bovine serum (FBS) is used to expand the chondrocytes. However, the use of FBS is not ideal for the expansion of cells mean for clinical applications as it possesses the risk of animal pathogen transmission and animal protein transfer to host. Human platelet lysate (HPL) appears to be a suitable alternative to FBS as it is rich in biological factors that enhance cell proliferation. Thus far, HPL has been found to be superior in promoting chondrocyte proliferation compared to FBS. However, both HPL and FBS cannot prevent chondrocyte dedifferentiation. Discrepant results have been reported for the maintenance of chondrocyte redifferentiation potential by HPL. These differences are likely due to the diversity in the HPL preparation methods. In the future, more studies on HPL need to be performed to develop a standardized technique which is capable of producing HPL that can maintain the chondrocyte redifferentiation potential reproducibly. This review discusses the in vitro expansion of chondrocytes with FBS and HPL, focusing on its capability to promote the proliferation and maintain the chondrogenic characteristics of chondrocytes.
    Matched MeSH terms: Culture Media/chemistry
  15. Mohd Tap R, Lim TC, Kamarudin NA, Ginsapu SJ, Abd Razak MF, Ahmad N, et al.
    Mycopathologia, 2018 Jun;183(3):559-564.
    PMID: 29383574 DOI: 10.1007/s11046-018-0244-y
    We report a fatal case of Candida auris that was involved in mixed candidemia with Candida tropicalis, isolated from the blood of a neutropenic patient. Identification of both isolates was confirmed by amplification and sequencing of internal transcribed spacer and D1/D2 domain of large subunit in rRNA gene. Antifungal susceptibility test by E-test method revealed that C. auris was resistant to amphotericin B, anidulafungin, caspofungin, fluconazole, itraconazole and voriconazole. On the other hand, C. tropicalis was sensitive to all antifungal tested. The use of chromogenic agar as isolation media is vital in detecting mixed candidemia.
    Matched MeSH terms: Culture Media/chemistry
  16. Taha RM, Haron NW
    Pak J Biol Sci, 2008 Apr 01;11(7):1021-6.
    PMID: 18810972
    In the present study, various explants of Murraya paniculata (Jack) Linn., such as cotyledons, shoots and young stems were cultured on MS medium supplemented with various concentrations of Benzyl Amino Purine (BAP) under 25 +/- 1 degree C with 16 h light and 8 h dark and also 8 h light and 16 h dark to obtain complete plant regeneration. In vitro flowering was observed from shoot explants cultured on MS supplemented with 0.5-2.0 mg L(-1) Naphthalene Acetic Acid (NAA) and also on MS basal medium under similar conditions. The leaves and flowers obtained from both in vivo and in vitro conditions were examined and compared. Morphological studies such as leaf clearing, epidermal peeling were studied using light and scanning electron microscope. Macromorphological studies of the flowers produced from in vivo and in vitro conditions were also examined. Morphologically, there were no differences between in vivo and in vitro flowers except the flowers produced from tissue culture systems were smaller in size with protruding stigmas. Differences were also found in the number of layers of palisade cells and the presence or absence of epicuticle layer of the leaves. Leaves produced from tissue culture system were smaller in size with membranous texture. Stomata were present only on the abaxial surfaces of both in vivo and in vitro leaves but the stomata were raised above the epidermis in the latter.
    Matched MeSH terms: Culture Media/chemistry
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