Displaying publications 1601 - 1620 of 9214 in total

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  1. Fulltext Dilute acid-assisted microbubbles-mediated ozonolysis of Eucheuma denticulatum phycocolloid for biobased L-lactic acid production
    Tong KTX, Tan IS, Foo HCY, Hadibarata T, Lam MK, Wong MK
    Bioresour Technol, 2024 Aug;406:131082.
    PMID: 38972432 DOI: 10.1016/j.biortech.2024.131082
    Biobased L-lactic acid (L-LA) appeals to industries; however, existing technologies are plagued by limited productivity and high energy consumption. This study established an integrated process for producing macroalgae-based L-LA from Eucheuma denticulatum phycocolloid (EDP). Dilute acid-assisted microbubbles-mediated ozonolysis (DAMMO) was selected for the ozonolysis of EDP to optimize D-galactose recovery. Through single-factor optimization of DAMMO treatment, a maximum D-galactose recovery efficiency (59.10 %) was achieved using 0.15 M H2SO4 at 80 °C for 75 min. Fermentation with 3 % (w/v) mixed microbial cells (Bacillus coagulans ATCC 7050 and Lactobacillus acidophilus-14) and fermented residues achieved a 97.67 % L-LA yield. Additionally, this culture approach was further evaluated in repeated-batch fermentation and showed an average L-LA yield of 93.30 %, providing a feasible concept for macroalgae-based L-LA production.
    Matched MeSH terms: Galactose/metabolism; Lactobacillus acidophilus/metabolism
  2. Improvement of ɣ-Aminobutyric Acid Production and Cell Viability of Lactiplantibacillus plantarum B7 via Whole-Cell Immobilisation in Repeated Batch Fermentation System
    Pannerchelvan S, Muhamad FN, Wasoh H, Mohamed MS, Wong FWF, Mohamad R, et al.
    Probiotics Antimicrob Proteins, 2024 Dec;16(6):1907-1924.
    PMID: 38085437 DOI: 10.1007/s12602-023-10200-4
    Whole-cell immobilisation technology involving ℽ-aminobutyric acid GABA biosynthesis using lactic acid bacteria (LAB) has been extensively studied owing to its numerous benefits over free-living bacteria, including enhanced productivity, improved cell viability, ability to prevent cell lysis and protect cells against bacteriophages and other stressful conditions. Therefore, a novel LAB biocatalyst was developed using various fruit and fruit waste, immobilising a potential probiotic strain, Lactiplantibacillus plantarum B7, via an adsorption method to improve GABA and cell viability. Apple and watermelon rind have been known to be the ideal natural supports for L. plantarum B7 owing to higher GABA and lactic acid production and improved cell viability among the other natural supports tested and selected to be used in repeated batch fermentation (RBF) to improve GABA production and cell viability. In general, immobilisation of L. plantarum B7 on natural support has better GABA and lactic acid production with improved cell viability via RBF compared to free cells. Watermelon rind-supported cells and apple-supported cells could produce nine and eight successful GABA cycles, respectively, within RBF, whereas free cells could only produce up to four cycles. When using watermelon rind-supported cells and apple-supported cells in RBF, the GABA titer may be raised by up to 6.7 (218.480 ± 0.280 g/L) and 6 (195.439 ± 0.042 g/L) times, respectively, in comparison to GABA synthesis by free cells in single batch fermentation (32.65 ± 0.029 g/L). Additionally, natural support immobilised L. plantarum B7 could retain half of its cell viability even after the 12th cycle of RBF, while no cell was observed in control.
    Matched MeSH terms: Lactic Acid/metabolism; Probiotics/metabolism
  3. Quantitatively characterize the response of the hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) under elevated temperature stress
    Zheng R, Lai X, Fang C, Lin H, Huang Y, Zheng J, et al.
    Mar Environ Res, 2024 Nov;202:106758.
    PMID: 39305860 DOI: 10.1016/j.marenvres.2024.106758
    Global warming may affect the health of marine species. However, the collected information on quantitative assessment of response in fish under elevated temperature is poorly defined. The present study aimed to quantitatively evaluate the effects of the hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) under elevated temperature (33 °C and 36 °C, ET1 and ET2) stress for 14 days. As endpoints, we examined changes in body growth, hemato-immunological parameters, liver oxidative stress markers, as well as changes of the stomach digestive enzymes. Compared to the control, the body weight was significantly decreased in ET2 group for 14 d exposure, and a remarkable change of differential leukocyte counts of the fish was observed in ET1 group at 3 d and in ET2 group at 14 d. The respiratory burst activity of the hybrid grouper leukocytes markedly decreased in the treatment groups after 14-d exposure. Overall, the antioxidant enzyme activities and transcriptional levels of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione peroxidase (GSH-PX) were markedly inhibited in the liver for 3-d and 14-d exposure. The expression levels of nf-κb mRNA were significantly inhibited while the expression levels of atp2b1 mRNA were significantly induced after 14-d exposure. The activities of pepsin and lipase in the stomach were significantly reduced. In addition, an innovative hazard classification system (ET-HCS) was developed to quantitatively characterize the stress response of the fish following elevated temperature treatments. The stress level of ET2 group for 14-d exposure was ranked as level IV (high stress), and the other treatments were ranked as level II (low stress). Taken together, the findings of this study further extend our understanding of quantitative assessment of response in fish under high-temperature stress, which provides valuable information for improving countermeasures of mariculture industry.
    Matched MeSH terms: Catalase/metabolism; Superoxide Dismutase/metabolism
  4. Proteomes of plasmodium knowlesi early and late ring-stage parasites and infected host erythrocytes
    Anderson DC, Peterson MS, Lapp SA, Galinski MR
    J Proteomics, 2024 Jun 30;302:105197.
    PMID: 38759952 DOI: 10.1016/j.jprot.2024.105197
    The emerging malaria parasite Plasmodium knowlesi threatens the goal of worldwide malaria elimination due to its zoonotic spread in Southeast Asia. After brief ex-vivo culture we used 2D LC/MS/MS to examine the early and late ring stages of infected Macaca mulatta red blood cells harboring P. knowlesi. The M. mulatta clathrin heavy chain and T-cell and macrophage inhibitor ERMAP were overexpressed in the early ring stage; glutaredoxin 3 was overexpressed in the late ring stage; GO term differential enrichments included response to oxidative stress and the cortical cytoskeleton in the early ring stage. P. knowlesi clathrin heavy chain and 60S acidic ribosomal protein P2 were overexpressed in the late ring stage; GO term differential enrichments included vacuoles in the early ring stage, ribosomes and translation in the late ring stage, and Golgi- and COPI-coated vesicles, proteasomes, nucleosomes, vacuoles, ion-, peptide-, protein-, nucleocytoplasmic- and RNA-transport, antioxidant activity and glycolysis in both stages. SIGNIFICANCE: Due to its zoonotic spread, cases of the emerging human pathogen Plasmodium knowlesi in southeast Asia, and particularly in Malaysia, threaten regional and worldwide goals for malaria elimination. Infection by this parasite can be fatal to humans, and can be associated with significant morbidity. Due to zoonotic transmission from large macaque reservoirs that are untreatable by drugs, and outdoor biting mosquito vectors that negate use of preventive measures such as bed nets, its containment remains a challenge. Its biology remains incompletely understood. Thus we examine the expressed proteome of the early and late ex-vivo cultured ring stages, the first intraerythrocyte developmental stages after infection of host rhesus macaque erythrocytes. We used GO term enrichment strategies and differential protein expression to compare early and late ring stages. The early ring stage is characterized by the enrichment of P. knowlesi vacuoles, and overexpression of the M. mulatta clathrin heavy chain, important for clathrin-coated pits and vesicles, and clathrin-mediated endocytosis. The M. mulatta protein ERMAP was also overexpressed in the early ring stage, suggesting a potential role in early ring stage inhibition of T-cells and macrophages responding to P. knowlesi infection of reticulocytes. This could allow expansion of the host P. knowlesi cellular niche, allowing parasite adaptation to invasion of a wider age range of RBCs than the preferred young RBCs or reticulocytes, resulting in proliferation and increased pathogenesis in infected humans. Other GO terms differentially enriched in the early ring stage include the M. mulatta cortical cytoskeleton and response to oxidative stress. The late ring stage is characterized by overexpression of the P. knowlesi clathrin heavy chain. Combined with late ring stage GO term enrichment of Golgi-associated and coated vesicles, and enrichment of COPI-coated vesicles in both stages, this suggests the importance to P. knowlesi biology of clathrin-mediated endocytosis. P. knowlesi ribosomes and translation were also differentially enriched in the late ring stage. With expression of a variety of heat shock proteins, these results suggest production of folded parasite proteins is increasing by the late ring stage. M. mulatta endocytosis was differentially enriched in the late ring stage, as were clathrin-coated vesicles and endocytic vesicles. This suggests that M. mulatta clathrin-based endocytosis, perhaps in infected reticulocytes rather than mature RBC, may be an important process in the late ring stage. Additional ring stage biology from enriched GO terms includes M. mulatta proteasomes, protein folding and the chaperonin-containing T complex, actin and cortical actin cytoskeletons. P knowlesi biology also includes proteasomes, as well as nucleosomes, antioxidant activity, a variety of transport processes, glycolysis, vacuoles and protein folding. Mature RBCs have lost internal organelles, suggesting infection here may involve immature reticulocytes still retaining organelles. P. knowlesi parasite proteasomes and translational machinery may be ring stage drug targets for known selective inhibitors of these processes in other Plasmodium species. To our knowledge this is the first examination of more than one timepoint within the ring stage. Our results expand knowledge of both host and parasite proteins, pathways and organelles underlying P. knowlesi ring stage biology.
    Matched MeSH terms: Malaria/metabolism; Protozoan Proteins/metabolism
  5. Fulltext Bioactive Compounds of Ganoderma boninense Inhibited Methicillin-Resistant Staphylococcus aureus Growth by Affecting Their Cell Membrane Permeability and Integrity
    Chan YS, Chong KP
    Molecules, 2022 Jan 27;27(3).
    PMID: 35164103 DOI: 10.3390/molecules27030838
    Some species of Ganoderma, such as G. lucidum, are well-known as traditional Chinese medicine (TCM), and their pharmacological value was scientifically proven in modern days. However, G. boninense is recognized as an oil palm pathogen, and its biological activity is scarcely reported. Hence, this study aimed to investigate the antibacterial properties of G. boninense fruiting bodies, which formed by condensed mycelial, produced numerous and complex profiles of natural compounds. Extract was cleaned up with normal-phase SPE and its metabolites were analyzed using liquid chromatography-mass spectrometry (LCMS). From the disc diffusion and broth microdilution assays, strong susceptibility was observed in methicillin-resistant Staphylococcus aureus (MRSA) in elute fraction with zone inhibition of 41.08 ± 0.04 mm and MIC value of 0.078 mg mL-1. A total of 23 peaks were detected using MS, which were putatively identified based on their mass-to-charge ratio (m/z), and eight compounds, which include aristolochic acid, aminoimidazole ribotide, lysine sulfonamide 11v, carbocyclic puromycin, fenbendazole, acetylcaranine, tigecycline, and tamoxifen, were reported in earlier literature for their antimicrobial activity. Morphological observation via scanning electron microscope (SEM), cell membrane permeability, and integrity assessment suggest G. boninense extract induces irreversible damage to the cell membrane of MRSA, thus causing cellular lysis and death.
    Matched MeSH terms: Cell Membrane/metabolism*; Methicillin-Resistant Staphylococcus aureus/metabolism*
  6. Fulltext Berberine nanostructures attenuate ß-catenin, a key component of epithelial mesenchymal transition in lung adenocarcinoma
    Malyla V, De Rubis G, Paudel KR, Chellappan DK, Hansbro NG, Hansbro PM, et al.
    Naunyn Schmiedebergs Arch Pharmacol, 2023 Dec;396(12):3595-3603.
    PMID: 37266589 DOI: 10.1007/s00210-023-02553-y
    Lung cancer (LC) is the leading cause of cancer-related deaths globally. It accounts for more than 1.9 million cases each year due to its complex and poorly understood molecular mechanisms that result in unregulated cell proliferation and metastasis. β-Catenin is a developmentally active protein that controls cell proliferation, metastasis, polarity and cell fate during homeostasis and aids in cancer progression via epithelial-mesenchymal transition. Therefore, inhibition of the β-catenin pathway could attenuate the progression of LC. Berberine, an isoquinoline alkaloid which is known for its anti-cancer and anti-inflammatory properties, demonstrates poor solubility and bioavailability. In our study, we have encapsulated berberine into liquid crystalline nanoparticles to improve its physiochemical functions and studied if these nanoparticles target the β-catenin pathway to inhibit the human lung adenocarcinoma cell line (A549) at both gene and protein levels. We observed for the first time that berberine liquid crystalline nanoparticles at 5 µM significantly attenuate the expression of the β-catenin gene and protein. The interaction between berberine and β-catenin was further validated by molecular simulation studies. Targeting β-catenin with berberine nanoparticles represents a promising strategy for the management of lung cancer progression.
    Matched MeSH terms: beta Catenin/metabolism; Catenins/metabolism
  7. Upregulation of miR-424 inhibit retinal endothelial cells proliferation under high glucose condition via cyclin D1
    Chen Y, Chen K, Zhu W, Chen J, Huang Z
    Malays J Pathol, 2024 Aug;46(2):279-286.
    PMID: 39207004
    INTRODUCTION: Diabetic retinopathy is characterised by retinal vascular impairment. A number of aberrant microRNAs (miRNAs) have a role in the pathophysiology of vascular dysfunction. However, the relevance of miR-424 in retinal vascular endothelial cell dysfunction during hyperglycemia stress remains unknown. The purpose of this study is to investigate this issue.

    MATERIALS AND METHODS: Rhesus macaque choroid retinal endothelial cell line (RF/6A) cells were cultivated in normal glucose (NG) and high glucose (HG) conditions. The mRNA expression of miR-424 and Cyclin D1 (CCND1) was quantified using qPCR, and the protein quantity of CCND1 was detected using Western Blot. miR-424 mimics, miR-424 inhibitors, miR-424 inhibitor+ siRNA-CCND1 or vehicle molecules were transfected into RF/6A cells. MTT test was used to assess cell proliferation, and flow cytometric analysis was used to assess cell cycle. The interaction between miR-424 and CCND1 was predicted using bioinformatics and validated using dual luciferase reporter analysis.

    RESULTS: miR-424 was up-regulated, and cell viability was reduced in HG compared to NG. By reversing the expression of miR-424 in certain situations, the phenotypes can be changed. CCND1 has been identified as a miR-424 target gene, and it may be regulated at the transcriptional and translational levels. Manipulation of silencing CCND1 can counteract the effect of transfecting miR-424 inhibitor into RF/6A cells under HG such as proliferation stimulation.

    CONCLUSIONS: Our findings indicate that miR-424 plays an important role in hyperglycemia induced ARPE-19 cells damage, and it could be a new therapeutic target for DR by preventing retinal vascular cells from HG-induced injury.

    Matched MeSH terms: Diabetic Retinopathy/metabolism; Retina/metabolism
  8. Fulltext Chronic unpredictable stress (CUS) reduced phoenixin expression, induced abnormal sperm and testis morphology in male rats
    Mohamed ZI, Sivalingam M, Radhakrishnan AK, Jaafar F, Zainal Abidin SA
    Neuropeptides, 2024 Oct;107:102447.
    PMID: 38870753 DOI: 10.1016/j.npep.2024.102447
    Chronic stress caused by prolonged emotional pressure can lead to various physiological issues, including reproductive dysfunction. Although reproductive problems can also induce chronic stress, the impact of chronic stress-induced reproductive dysfunction remains contentious. This study investigates the effects of chronic unpredictable stress (CUS) on reproductive neuropeptides, sperm quality, and testicular morphology. Sixteen twelve-week-old Sprague Dawley rats were divided into two groups: a non-stress control group and a CUS-induced group. The CUS regimen involved various stressors over 28 days, with both groups undergoing behavioural assessments through sucrose-preference and forced-swim tests. Hypothalamic gene expression levels of CRH, PNX, GPR173, kisspeptin, GnRH, GnIH, and spexin neuropeptides were measured via qPCR, while plasma cortisol, luteinizing hormone (LH), and testosterone concentrations were quantified using ELISA. Seminal fluid and testis samples were collected for sperm analysis and histopathological evaluation, respectively. Results showed altered behaviours in CUS-induced rats, reflecting stress impacts. Hypothalamic corticotropin-releasing hormone (CRH) expression and plasma cortisol levels were significantly higher in CUS-induced rats compared to controls (p 
    Matched MeSH terms: Hypothalamus/metabolism; Neuropeptides/metabolism
  9. Fulltext The Role of Cyclin d1 in Radiotherapy Resistance of Advance Stage Nasopharyngeal Carcinoma: A Systematic Review
    Romdhoni AC, Rajanagara AS, Albab CF, Waskito LA, Wibowo IN, Yunus MRM
    Asian Pac J Cancer Prev, 2024 Jul 01;25(7):2211-2218.
    PMID: 39068551 DOI: 10.31557/APJCP.2024.25.7.2211
    OBJECTIVE: One of the biggest therapy challenges for nasopharyngeal cancer (NPC) is still radioresistance.  The radioresistance in NPC is thought to be caused by cyclin D1 overexpression.  The purpose of this study was to determine how cyclin D1 contributes to radiation resistance in NPC.

    METHODS: Adhering to the PRISMA guidelines, we systematically reviewed studies on cyclin D1-associated radioresistance in NPC from 2012 until 2023.  From our search, 15 studies were included.

    RESULTS: Cyclin D1's role in radiotherapy resistance is elucidated through several mechanisms, notably SHP-1 and B-catenin. Overexpression of SHP-1 led to an increase in cyclin D1, a higher proportion of cells in the S-phase, and radioresistance.  Conversely, inhibiting β-catenin and cyclin D1 expression enhances radiation sensitivity.

    CONCLUSION: In conclusion, Cyclin D1 has a strong correlation with radiation resistance; downregulation of the protein increases radiosensitivity, while overexpression of the protein promotes radioresistance.

    Matched MeSH terms: beta Catenin/metabolism; Protein Tyrosine Phosphatase, Non-Receptor Type 6/metabolism
  10. Tocotrienol-rich fraction (TRF) protects against retinal cell apoptosis and preserves visual behavior in rats with streptozotocin-induced diabetic retinopathy
    Goh Y, Sadikan MZ, Jaiprakash H, Nasir NAA, Agarwal R, Iezhitsa I, et al.
    BMC Complement Med Ther, 2024 Aug 30;24(1):322.
    PMID: 39215295 DOI: 10.1186/s12906-024-04614-y
    BACKGROUND: Tocotrienol is a vitamin E analogue that is known to exert anti-inflammatory and antioxidant effects. Hence, in the current study, the effects of TRF on the expression of pro- and anti-apoptotic proteins in the streptozotocin-induced diabetic rat retinas were investigated. The effect of TRF on the visual behaviour of rats was also studied.

    METHODS: Diabetes was induced in rats by intraperitoneal injection of streptozotocin and was confirmed by a blood sugar level of at least 20 mmol/L, 48 h, post-injection. Diabetic rats were divided into a group treated with vehicle (DV) and the other treated with TRF (100 mg/kg; DT). A group of non-diabetic rats treated with vehicle (N) served as the control group. All treatments were administered orally for 12 weeks. Rats were then subjected to an assessment of general behaviour in an open field arena and a two-chamber mirror test to assess their visual behaviour. At the end of the experimental period, rats were sacrificed, and their retinas were isolated to measure the expression of pro- (Casp3, Bax) and anti-apoptotic (Bcl2) markers using RT-qPCR and ELISA. TUNEL staining was used to detect the apoptotic retinal cells.

    RESULTS: Treatment with TRF lowered the retinal expression of Casp3 protein by 2.26-folds (p 

    Matched MeSH terms: bcl-2-Associated X Protein/metabolism; Caspase 3/metabolism
  11. Exploring bradykinin: A common mediator in the pathophysiology of sepsis and atherosclerotic cardiovascular disease
    Siti-Zubaidah MZ, Harafinova HS, Liba AN, Nordin ML, Hambali KA, Siti HN
    Vascul Pharmacol, 2024 Sep;156:107414.
    PMID: 39089528 DOI: 10.1016/j.vph.2024.107414
    Sepsis and atherosclerotic cardiovascular disease (ASCVD) are major health challenges involving complex processes like inflammation, renin-angiotensin system (RAS) dysregulation, and thrombosis. Despite distinct clinical symptoms, both conditions share mechanisms mediated by bradykinin. This review explores bradykinin's role in inflammation, RAS modulation, and thrombosis in sepsis and ASCVD. In sepsis, variable kininogen-bradykinin levels may correlate with disease severity and progression, though the effect of bradykinin receptor modulation on inflammation remains uncertain. RAS activation is present in both diseases, with sepsis showing variable or low levels of Ang II, ACE, and ACE2, while ASCVD consistently exhibits elevated levels. Bradykinin may act as a mediator for ACE2 and AT2 receptor effects in RAS regulation. It may influence clotting and fibrinolysis in sepsis-associated coagulopathy, but evidence for an antithrombotic effect in ASCVD is insufficient. Understanding bradykinin's role in these shared pathologies could guide therapeutic and monitoring strategies and inform future research.
    Matched MeSH terms: Thrombosis/metabolism; Receptors, Bradykinin/metabolism
  12. Nodamura virus B2 amino terminal domain sensitivity to small interfering RNA
    Ali PS, John J, Selvaraj M, Kek TL, Salleh MZ
    Microbiol. Immunol., 2015 May;59(5):299-304.
    PMID: 25753649 DOI: 10.1111/1348-0421.12253
    Nodamura virus (NoV) B2, a suppressor of RNA interference, binds double stranded RNAs (dsRNAs) and small interfering RNAs (siRNAs) corresponding to Dicer substrates and products. Here, we report that the amino terminal domain of NoV B2 (NoV B2 79) specifically binds siRNAs but not dsRNAs. NoV B2 79 oligomerizes on binding to 27 nucleotide siRNA. Mutation of the residues phenylalanine49 and alanine60 to cysteine and methionine, respectively enhances the RNA binding affinity of NoV B2 79. Circular dichroism spectra demonstrated that the wild type and mutant NoV B2 79 have similar secondary structure conformations.
    Matched MeSH terms: RNA, Double-Stranded/metabolism; Viral Proteins/metabolism*; RNA-Binding Proteins/metabolism*; RNA, Small Interfering/metabolism*; Mutant Proteins/metabolism
  13. Distribution and health risk assessment of trace metals in freshwater tilapia from three different aquaculture sites in Jelebu Region (Malaysia)
    Low KH, Zain SM, Abas MR, Md Salleh K, Teo YY
    Food Chem, 2015 Jun 15;177:390-6.
    PMID: 25660902 DOI: 10.1016/j.foodchem.2015.01.059
    The trace metal concentrations in edible muscle of red tilapia (Oreochromis spp.) sampled from a former tin mining pool, concrete tank and earthen pond in Jelebu were analysed with microwave assisted digestion-inductively coupled plasma-mass spectrometry. Results were compared with established legal limits and the daily ingestion exposures simulated using the Monte Carlo algorithm for potential health risks. Among the metals investigated, arsenic was found to be the key contaminant, which may have arisen from the use of formulated feeding pellets. Although the risks of toxicity associated with consumption of red tilapia from the sites investigated were found to be within the tolerable range, the preliminary probabilistic estimation of As cancer risk shows that the 95th percentile risk level surpassed the benchmark level of 10(-5). In general, the probabilistic health risks associated with ingestion of red tilapia can be ranked as follows: former tin mining pool > concrete tank > earthen pond.
    Matched MeSH terms: Arsenic/metabolism; Metals/metabolism; Muscles/metabolism; Water Pollutants, Chemical/metabolism; Tilapia/metabolism*
  14. Fulltext The use of protein-DNA, chromatin immunoprecipitation, and transcriptome arrays to describe transcriptional circuits in the dehydrated male rat hypothalamus
    Qiu J, Kleineidam A, Gouraud S, Yao ST, Greenwood M, Hoe SZ, et al.
    Endocrinology, 2014 Nov;155(11):4380-90.
    PMID: 25144923 DOI: 10.1210/en.2014-1448
    The supraoptic nucleus (SON) of the hypothalamus is responsible for maintaining osmotic stability in mammals through its elaboration of the antidiuretic hormone arginine vasopressin. Upon dehydration, the SON undergoes a function-related plasticity, which includes remodeling of morphology, electrical properties, and biosynthetic activity. This process occurs alongside alterations in steady state transcript levels, which might be mediated by changes in the activity of transcription factors. In order to identify which transcription factors might be involved in changing patterns of gene expression, an Affymetrix protein-DNA array analysis was carried out. Nuclear extracts of SON from dehydrated and control male rats were analyzed for binding to the 345 consensus DNA transcription factor binding sequences of the array. Statistical analysis revealed significant changes in binding to 26 consensus elements, of which EMSA confirmed increased binding to signal transducer and activator of transcription (Stat) 1/Stat3, cellular Myelocytomatosis virus-like cellular proto-oncogene (c-Myc)-Myc-associated factor X (Max), and pre-B cell leukemia transcription factor 1 sequences after dehydration. Focusing on c-Myc and Max, we used quantitative PCR to confirm previous transcriptomic analysis that had suggested an increase in c-Myc, but not Max, mRNA levels in the SON after dehydration, and we demonstrated c-Myc- and Max-like immunoreactivities in SON arginine vasopressin-expressing cells. Finally, by comparing new data obtained from Roche-NimbleGen chromatin immunoprecipitation arrays with previously published transcriptomic data, we have identified putative c-Myc target genes whose expression changes in the SON after dehydration. These include known c-Myc targets, such as the Slc7a5 gene, which encodes the L-type amino acid transporter 1, ribosomal protein L24, histone deactylase 2, and the Rat sarcoma proto-oncogene (Ras)-related nuclear GTPase.
    Matched MeSH terms: Dehydration/metabolism; DNA/metabolism; DNA-Binding Proteins/metabolism; Hypothalamus/metabolism*; Transcription Factors/metabolism
  15. Synthesis of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/chitosan/silver nanocomposite material with enhanced antimicrobial activity
    Rennukka M, Sipaut CS, Amirul AA
    Biotechnol Prog, 2014 Nov-Dec;30(6):1469-79.
    PMID: 25181613 DOI: 10.1002/btpr.1986
    This work aims to shed light in the fabrication of poly(3-hydroxybutyrate-co-44%-4-hydroxybutyrate)[P(3HB-co-44%4HB)]/chitosan-based silver nanocomposite material using different contents of silver nanoparticle (SNP); 1-9 wt%. Two approaches were applied in the fabrication; namely solvent casting and chemical crosslinking via glutaraldehyde (GA). A detailed characterization was conducted in order to yield information regarding the nanocomposite material. X-ray diffraction analysis exhibited the nature of the three components that exist in the nanocomposite films: P(3HB-co-4HB), chitosan, and SNP. In term of mechanical properties, tensile strength, and elongation at break were significantly improved up to 125% and 22%, respectively with the impregnation of the SNP. The melting temperature of the nanocomposite materials was increased whereas their thermal stability was slightly changed. Scanning electron microscopy images revealed that incorporation of 9 wt% of SNP caused agglomeration but the surface roughness of the material was significantly improved with the loading. Staphylococcus aureus and Escherichia coli were completely inhibited by the nanocomposite films with 7 and 9 wt% of SNP, respectively. On the other hand, degradation of the nanocomposite materials outweighed the degradation of the pure copolymer. These bioactive and biodegradable materials stand a good chance to serve the vast need of biomedical applications namely management and care of wound as wound dressing.
    Matched MeSH terms: Anti-Infective Agents/metabolism*; Hydroxybutyrates/metabolism*; Polyesters/metabolism*; Silver/metabolism*; Chitosan/metabolism*
  16. Fulltext Unusual multiple production of N-acylhomoserine lactones a by Burkholderia sp. strain C10B isolated from dentine caries
    Goh SY, Tan WS, Khan SA, Chew HP, Abu Kasim NH, Yin WF, et al.
    Sensors (Basel), 2014;14(5):8940-9.
    PMID: 24854358 DOI: 10.3390/s140508940
    Bacteria realize the ability to communicate by production of quorum sensing (QS) molecules called autoinducers, which regulate the physiological activities in their ecological niches. The oral cavity could be a potential area for the presence of QS bacteria. In this study, we report the isolation of a QS bacterial isolate C10B from dentine caries. Preliminary screening using Chromobacterium violaceum CV026 biosensor showed that isolate C10B was able to produce N-acylhomoserine lactones (AHLs). This bacterium was further identified as a member of Burkholderia, an opportunistic pathogen. The isolated Burkholderia sp. was confirmed to produce N-hexanoyl-L-homoserine lactone (C6-HSL), N-octanoyl-L-homoserine lactone (C8-HSL), N-decanoyl-L-homoserine lactone (C10-HSL) and N-dodecanoyl-L-homoserine lactone (C12-HSL).
    Matched MeSH terms: Homoserine/metabolism; Lactones/metabolism; 4-Butyrolactone/metabolism; Burkholderia/metabolism*; Acyl-Butyrolactones/metabolism*
  17. Fulltext Allocation of secondary metabolites, photosynthetic capacity, and antioxidant activity of Kacip Fatimah (Labisia pumila Benth) in response to CO2 and light intensity
    Ibrahim MH, Jaafar HZ, Karimi E, Ghasemzadeh A
    ScientificWorldJournal, 2014;2014:360290.
    PMID: 24683336 DOI: 10.1155/2014/360290
    A split plot 3 by 4 experiment was designed to investigate and distinguish the relationships among production of secondary metabolites, soluble sugar, phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity, leaf gas exchange, chlorophyll content, antioxidant activity (DPPH), and lipid peroxidation under three levels of CO2 (400, 800, and 1200 μ mol/mol) and four levels of light intensity (225, 500, 625, and 900 μ mol/m(2)/s) over 15 weeks in Labisia pumila. The production of plant secondary metabolites, sugar, chlorophyll content, antioxidant activity, and malondialdehyde content was influenced by the interactions between CO2 and irradiance. The highest accumulation of secondary metabolites, sugar, maliondialdehyde, and DPPH activity was observed under CO2 at 1200 μ mol/mol + light intensity at 225 μ mol/m(2)/s. Meanwhile, at 400 μ mol/mol CO2 + 900 μ mol/m(2)/s light intensity the production of chlorophyll and maliondialdehyde content was the highest. As CO2 levels increased from 400 to 1200 μ mol/mol the photosynthesis, stomatal conductance, f v /f m (maximum efficiency of photosystem II), and PAL activity were enhanced. The production of secondary metabolites displayed a significant negative relationship with maliondialdehyde indicating lowered oxidative stress under high CO2 and low irradiance improved the production of plant secondary metabolites that simultaneously enhanced the antioxidant activity (DPPH), thus improving the medicinal value of Labisia pumila under this condition.
    Matched MeSH terms: Antioxidants/metabolism*; Secondary Metabolism/drug effects; Secondary Metabolism/physiology*; Secondary Metabolism/radiation effects
  18. Neuroprotective effects of orientin on hydrogen peroxide‑induced apoptosis in SH‑SY5Y cells
    Law BN, Ling AP, Koh RY, Chye SM, Wong YP
    Mol Med Rep, 2014 Mar;9(3):947-54.
    PMID: 24366367 DOI: 10.3892/mmr.2013.1878
    Neurodegenerative diseases remain a global issue which affects the ageing population. Efforts towards determining their aetiologies to understand their pathogenic mechanisms are underway in order to identify a pathway through which therapeutic measures can be applied. One such pathogenic mechanism, oxidative stress (OS), is widely considered to be involved in neurodegenerative disease. Antioxidants, most notably flavonoids, have promising potential for therapeutic use as shown in in vitro and in vivo studies. In view of the importance of flavonoids for combating OS, this study investigated the neuroprotective effects of orientin, which has been reported to be capable of crossing the blood‑brain barrier. The maximum non‑toxic dose (MNTD) of orientin against SH‑SY5Y neuroblastoma cells was determined using a 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide (MTT) assay. The effects of the MNTD and the half MNTD (½MNTD) of orientin on cell cycle progression and intracellular reactive oxygen species (ROS) levels, as well as the activity of caspases 3/7, 8 and 9 after exposure to 150 µM of hydrogen peroxide (H2O2) were also determined using flow cytometry, a 2',7'‑dichlorodihydrofluorescein‑diacetate (DCFH‑DA) assay and caspase assay kits, respectively. The results revealed that orientin at ≤20 µM was not cytotoxic to SH‑SY5Y cells. After treatment with orientin at the MNTD, the percentage of apoptotic cells was significantly reduced compared with that in cells treated with 150 µM H2O2 alone. The results also showed that, although orientin at the MNTD and ½MNTD did not reduce intracellular ROS levels, it significantly inhibited the activity of caspases 3/7. Caspase 9 was significantly inactivated with orientin at the MNTD. Findings from this study suggest that the neuroprotection conferred by orientin was the result of the intracellular mediation of caspase activity.
    Matched MeSH terms: Reactive Oxygen Species/metabolism; Caspase 3/metabolism; Caspase 7/metabolism; Caspase 8/metabolism; Caspase 9/metabolism
  19. Induction of protein expression within Escherichia coli vector for entry into mammalian cells
    Chen Q, Lee CW, Sim EU, Narayanan K
    Hum Gene Ther Methods, 2014 Feb;25(1):40-7.
    PMID: 24134118 DOI: 10.1089/hgtb.2012.188
    Direct protein delivery into the cytosol of mammalian cells by invasive Escherichia coli (E. coli) bacterial vector will bypass the need to achieve nuclear entry and transcription of DNA, a major hurdle that is known to seriously limit gene transfer. The bacterial vector is induced to express the protein during its growth phase, before presentation for entry into mammalian cells and release of its content into the cellular environment. For this class of vector, crossing the plasma membrane becomes the primary step that determines the success of protein delivery. Yet, how the mechanics of protein expression within the vector affect its entry into the host is poorly understood. We found the vector's effectiveness to enter HeLa cells diminished together with its viability when phage N15 protelomerase (TelN) expression was induced continuously in the invasive E. coli despite producing an abundant amount of functional protein. By comparison, shorter induction, even as little as 3 hr, produced sufficient amounts of functional TelN and showed more effective invasion of HeLa cells, comparable to that of uninduced invasive E. coli. These results demonstrate that brief induction of protein expression during vector growth is essential for optimal entry into mammalian cells, an important step for achieving bacteria-mediated protein delivery.
    Matched MeSH terms: Enzyme Precursors/metabolism; Escherichia coli/metabolism; Plasmids/metabolism*; Viral Proteins/metabolism; Telomerase/metabolism
  20. An assessment of heavy metal bioaccumulation in Asian swamp eel, Monopterus albus, during plowing stages of a paddy cycle
    Sow AY, Ismail A, Zulkifli SZ
    Bull Environ Contam Toxicol, 2013 Jul;91(1):6-12.
    PMID: 23666324 DOI: 10.1007/s00128-013-1009-4
    Livers and muscles of swamp eels (Monopterus albus) were analyzed for bioaccumulation of heavy metals during the plowing stage of a paddy cycle. Results showed heavy metals were bioaccumulated more highly in liver than muscle. Zinc (Zn) was the highest bioaccumulated metal in liver (98.5 ± 8.95 μg/g) and in muscle (48.8 ± 7.17 μg/g). The lowest bioaccumulated metals were cadmium (Cd) in liver (3.44 ± 2.42 μg/g) and copper (Cu) in muscle (0.65 ± 0.20 μg/g). In sediments, Zn was present at the highest mean concentration (52.7 ± 2.85 μg/g), while Cd had the lowest mean concentration (1.04 ± 0.24 μg/g). The biota-sediment accumulation factor (BSAF) for Cu, Zn, Cd and nickel (Ni) in liver tissue was greater than the corresponding BSAF for muscle tissue. For the three plowing stages, metal concentrations were significantly correlated between liver and muscle tissues in all cases, and between sediment and either liver or muscle in most cases. Mean measured metal concentrations in muscle tissue were below the maximum permissible limits established by Malaysian and U.S. governmental agencies, and were therefore regarded as safe for human consumption.
    Matched MeSH terms: Liver/metabolism; Water Pollutants, Chemical/metabolism*; Muscle, Skeletal/metabolism; Metals, Heavy/metabolism*; Smegmamorpha/metabolism*
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