Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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PPAR-alpha dependent regulation of vanin-1 mediates hepatic lipid metabolism
Diepen, J.A. van; Jansen, P.A. ; Ballak, D.B. ; Hijmans, A. ; Hooiveld, G.J.E.J. ; Rommelaere, S. ; Kersten, A.H. ; Stienstra, R. - \ 2014
Journal of Hepatology 61 (2014)2. - ISSN 0168-8278 - p. 366 - 372.
high-fat diet - gene-expression - insulin-resistance - null mice - liver - cysteamine - tissue - acids - hepatocytes - fenofibrate
Background & Aims Peroxisome proliferator-activated receptor alpha (PPARa) is a key regulator of hepatic fat oxidation that serves as an energy source during starvation. Vanin-1 has been described as a putative PPARa target gene in liver, but its function in hepatic lipid metabolism is unknown. Methods We investigated the regulation of vanin-1, and total vanin activity, by PPARa in mice and humans. Furthermore, the function of vanin-1 in the development of hepatic steatosis in response to starvation was examined in Vnn1 deficient mice, and in rats treated with an inhibitor of vanin activity. Results Liver microarray analyses reveals that Vnn1 is the most prominently regulated gene after modulation of PPARa activity. In addition, activation of mouse PPARa regulates hepatic- and plasma vanin activity. In humans, consistent with regulation by PPARa, plasma vanin activity increases in all subjects after prolonged fasting, as well as after treatment with the PPARa agonist fenofibrate. In mice, absence of vanin-1 exacerbates the fasting-induced increase in hepatic triglyceride levels. Similarly, inhibition of vanin activity in rats induces accumulation of hepatic triglycerides upon fasting. Microarray analysis reveal that the absence of vanin-1 associates with gene sets involved in liver steatosis, and reduces pathways involved in oxidative stress and inflammation. Conclusions We show that hepatic vanin-1 is under extremely sensitive regulation by PPARa and that plasma vanin activity could serve as a readout of changes in PPARa activity in human subjects. In addition, our data propose a role for vanin-1 in regulation of hepatic TG levels during fasting. Abbreviations PPAR, Peroxisome proliferator-activated receptor; RXR, Retinoid X Receptor; VNN1, vanin-1; VNN2, vanin-2; VNN3, vanin-3; WT, wild-type; BMI, body mass index; Pan-AMC, pantothenate-7-amino-4-methylcoumarin; TG, Triglycerides; TC, total cholesterol; FFA, free fatty acids; KLF15, Kruppel-like factor 15; STAT3, signal transducer and activator of transcription 3; SP1, trans-acting transcription factor 1; CBFB, core binding factor beta; XBP1, x-box binding protein 1; NAFLD, non-alcoholic fatty liver disease; Pan-PNa, pantothenate-4-nitroanilide; Abcd2, chemokine (C-C motif) ligand 17; Acadm, acyl-CoA dehydrogenase, medium chain; Acot1, acyl-CoA thioesterase 1; Acot2, acyl-CoA thioesterase 2; Acsl5, acyl-CoA synthetase long-chain family member 5; Ehhadh, enoyl-CoA hydratase/3-hydroxylacyl CoA dehydrogenase; NASH, non-alcoholic steatohepatitis (NASH)
Genome-wide age-related changes in DNA methylation and gene expression in human PBMCs
Steegenga, W.T. ; Boekschoten, M.V. ; Lute, C. ; Hooiveld, G.J.E.J. ; Groot, P.J. de; Morris, T.J. ; Teschendorff, A.E. ; Butcher, L.M. ; Beck, S. ; Müller, M.R. - \ 2014
Age / the official journal of the American Aging Association 36 (2014)3. - ISSN 0161-9152 - p. 1523 - 1540.
activated receptor-alpha - human brain - transcriptional profile - caloric restriction - stem-cells - promoter - cancer - epigenetics - disease - tissue
Aging is a progressive process that results in the accumulation of intra- and extracellular alterations that in turn contribute to a reduction in health. Age-related changes in DNA methylation have been reported before and may be responsible for aging-induced changes in gene expression, although a causal relationship has yet to be shown. Using genome-wide assays, we analyzed age-induced changes in DNA methylation and their effect on gene expression with and without transient induction with the synthetic transcription modulating agent WY14,643. To demonstrate feasibility of the approach, we isolated peripheral blood mononucleated cells (PBMCs) from five young and five old healthy male volunteers and cultured them with or without WY14,643. Infinium 450K BeadChip and Affymetrix Human Gene 1.1 ST expression array analysis revealed significant differential methylation of at least 5 % (¿YO¿>¿5 %) at 10,625 CpG sites between young and old subjects, but only a subset of the associated genes were also differentially expressed. Age-related differential methylation of previously reported epigenetic biomarkers of aging including ELOVL2, FHL2, PENK, and KLF14 was confirmed in our study, but these genes did not display an age-related change in gene expression in PBMCs. Bioinformatic analysis revealed that differentially methylated genes that lack an age-related expression change predominantly represent genes involved in carcinogenesis and developmental processes, and expression of most of these genes were silenced in PBMCs. No changes in DNA methylation were found in genes displaying transiently induced changes in gene expression. In conclusion, aging-induced differential methylation often targets developmental genes and occurs mostly without change in gene expression.
Regeneration and transformation of Crambe abyssinica
Qi, W. ; Tinnenbroek-Capel, I.E.M. ; Schaart, J. ; Huang Bangquan, ; Cheng, J. ; Visser, R.G.F. ; Loo, E.N. van; Krens, F.A. - \ 2014
BMC Plant Biology 14 (2014). - ISSN 1471-2229 - 12 p.
gene - agrobacterium - tissue - plants
Background: Crambe abyssinica (crambe) is a non-food oil seed crop. Its seed oil is widely used in the chemical industry because of the high erucic acid content. Furthermore, it is a potential platform for various feedstock oils for industrial uses based on genetic modification. Here, we describe the development of a series of protocols for all steps required in the process of generating genetically modified crambe. Results: Different explant types from crambe seedlings were tested for shoot regeneration using different hormone-combinations. Cotyledonary nodes on basic medium with 0.5 µM NAA and 2.2 µM BAP gave the highest regeneration percentages. For propagation by tissue culture, explants of stems, petioles, leaves and axillary buds of in vitro plantlets were tested using the optimized medium. Axillary buds showed the highest shoot proliferation efficiency. Cotyledonary nodes were used to test the proper concentration of kanamycin for selection of transformation events, and 10 to 25 mg · L-1 were identified as effective. The cotyledonary nodes and cotyledons from 7-day-old seedlings were used in Agrobacterium-mediated transformations with two kinds of selection strategies, shifting or consistent. Using the shifting selection method (10 mg · L-1 kanamycin, 25 mg · L-1, then back to 10 mg · L-1) cotyledonary nodes gave 10% transformation frequency, and cotyledons 4%, while with the consistent method (25 mg · L-1) lower frequencies were found, 1% for cotyledonary nodes and 0% for cotyledons). Later, in vitro plant axillary buds were tried as explants for transformation, however, transformation frequency was low ranging from 0.5 to 2%. Overall, testing six different vectors and two kinds of Agrobacterium strains, the average transformation frequency using the shifting method was 4.4%. Determining T-DNA insertion numbers by Southern blotting showed that approximately 50% of the transgenic lines had a single-copy insertion. Conclusions: Present research revealed the potential of using crambe meristematic tissue for genetic transformation andin vitro propagation. The most efficient method of transformation used cotyledonary node explants from 7-days-old seedlings with a shifting kanamycin selection. Meristematic tissues (cotyledonary node or axillary bud) had the highest ability for shoot proliferation. Single-copy T-DNA insert lines could be efficiently and reproducibly generated.
Exploring the molecular link between swim-training and caudal fin development in zebrafish (Danio rerio) larvae
Fiaz, A.W. ; Leon, K.M. ; Leeuwen, J.L. van; Kranenbarg, S. - \ 2014
Journal of Applied Ichthyology 30 (2014)4. - ISSN 0175-8659 - p. 753 - 761.
transcription factor - mechanical control - gene-expression - bone - activation - forces - tissue - transhydrogenase - osteoblasts - contributes
In vitro and in vivo studies have shown that mechanical forces play an important role during development. The molecular mechanisms via which mechanical forces regulate development have been extensively investigated by in vitro studies. However, knowledge about the molecular pathways that mediate the effect of mechanical forces during development in vivo is limited. Previously, we showed that swim-training increased maximum normalized curvatures in the caudal fin (suggesting that the caudal fin experienced increased mechanical loads) and prioritized the development of skeletal structures in the caudal fin. Therefore, we used the zebrafish caudal fin to explore the molecular link between an increased swimming activity and development in vivo. Whole genome microarray analysis of caudal fins of zebrafish subjected to swim-training and control fish identified 46 genes which were up-regulated with a fold change of 1.5 or larger at 10 dpf. Fourteen genes were expressed specifically in the following tissues in the caudal fin: the neural tube, the tissue surrounding the hypurals, the finfold, or muscle fibers. Subsequently, we identified two muscle specific genes, aste1 (asteroid homolog 1) and zgc:65811, which showed an increased expression specifically in the caudal fin in response to swim-training. This makes these genes interesting candidate genes for further research on the molecular link between mechanical forces and caudal fin development. Our study is the first to investigate the molecular link between swim-training and caudal fin development and offers a system that can provide a deeper understanding of the link between mechanical and molecular signals during development in vivo.
Studies on the colonization of axenically grown tomato plants by a GFP-tagged strain of Clavibacter michiganensis subsp. michiganensis
Vieira Lelis, F.M. ; Czajkowski, R.L. ; Souza, R.M. de; Ribeiro, D.H. ; Wolf, J.M. van der - \ 2014
European Journal of Plant Pathology 139 (2014)1. - ISSN 0929-1873 - p. 53 - 66.
corynebacterium-michiganense - phytopathogenic bacterium - xylem sap - virulence - pathogens - tissue - seed - transmission - transplants - resistance
In this study, colonization and disease development of axenically-grown tomato plants by Clavibacter michiganensis subsp. michiganensis (Cmm), the causative agent of bacterial wilt and canker, was investigated. For this, a spontaneous rifampicin resistant strain of Cmm was tagged with a marker that expressed a green fluorescent protein (GFP) in a stable way and which possessed a similar virulence to the parental strain. In vitro plants were drop-inoculated at the stem base and the population dynamics was determined by dilution pour-plating in a selective medium. At 3 h after inoculation, Cmm was already present in low densities in roots, stems and leaves. At 16 dpi, Cmm was found throughout the entire plant in high densities of ca. 1010 cfu g-1. Symptoms developed in the in vitro plants typical for Cmm, such as canker, wilting and growth reduction. The presence of Cmm in vascular and parenchymatic tissue of in vitro tomato plants was confirmed by epifluorescence stereo- and confocal laser scanning microscopy. This study showed that in vitro tomato plants can be effectively used for detailed studies on interactions between Cmm and its host, in particular if a GFP-tagged strain of the pathogen is used
Gene coexpression network analysis identifies genes and biological processes shared among anterior pituitary and brain areas that affect estrous behavior in dairy cows
Kommadath, A. ; Pas, M.F.W. te; Smits, M.A. - \ 2013
Journal of Dairy Science 96 (2013)4. - ISSN 0022-0302 - p. 2583 - 2595.
expression patterns - quantitative measure - mechanisms - modules - tissue - transcriptome - endometrium - metabolism - fertility - discovery
The expression of estrous (sexually receptive) behavior (EB), a key fertility trait in dairy cows, has been declining over the past few decades both in intensity and duration. Improved knowledge of the genomic factors underlying EB, which is currently lacking, may lead to novel applications to enhance fertility. Our objective was to identify genes and biological processes shared among the bovine anterior pituitary (AP) and four brain areas that act together to regulate EB by investigating networks of coexpressed genes between these tissues. We used a systems biology approach called weighted gene coexpression network analysis for defining gene coexpression networks using gene expression data from the following tissues collected from 14 cows at estrus: AP, dorsal hypothalamus (DH), ventral hypothalamus (VH), amygdala (AM), and hippocampus (HC). Consensus modules of coexpressed genes were identified between the networks for the AM-DH, HC-DH, VH-DH, AP-DH, and AM-HC tissue pairs. The correlation between the module's eigengene (weighted average gene expression profile) and levels of EB exhibited by the experimental cows were tested. Estrous behavior-cor-related modules were found enriched for gene ontology terms like glial cell development and regulation of neural projection development as well as for Kyoto Encyclopedia of Genes and Genomes pathway terms related to brain degenerative diseases. General cellular processes like oxidative phosphorylation and ribosome and biosynthetic processes were found enriched in several correlated modules, indicating increased transcription and protein synthesis. Stimulation of ribosomal RNA synthesis is known from rodent studies to be a primary event in the activation of neuronal cells and pathways involved in female reproductive behavior and this precedes the estrogen-driven expansion of dendrites and synapses. Similar processes also operate in cows to affect EB. Hub genes within EB-correlated modules (e.g. NEFL, NDRG2, GAP43, THY1, and TCF7L2, among others) are strong candidates among genes regulating EB expression. The study improved our understanding of the genomic regulation of EB in dairy cows by providing new insights into genes and biological processes shared among the bovine AP and brain areas acting together to regulate EB. The new knowledge could lead to the development of novel management strategies to monitor and improve reproductive performance in dairy cows (for example, biomarkers for estrus detection).
Effects of short- and long-chain fatty acids on the expression of stearoyl-CoA desaturase and other lipogenic genes in bovine mammary epithelial cells
Jacobs, A.A.A. ; Dijkstra, J. ; Liesman, J.S. ; VandeHaar, M.J. ; Lock, A.L. ; Vuuren, A.M. van; Hendriks, W.H. ; Baal, J. van - \ 2013
Animal 7 (2013)9. - ISSN 1751-7311 - p. 1508 - 1516.
element-binding protein-1 - activated receptor-gamma - conjugated linoleic-acid - milk-fat - dairy-cows - lipid-synthesis - dietary-fat - tissue - lactation - networks
Stearoyl-CoA desaturase (SCD) in the bovine mammary gland introduces a cis-double bond at the ¿9 position in a wide range of fatty acids (FA). Several long-chain polyunsaturated fatty acids (PUFA) inhibit expression of SCD, but information on the effect of short-chain fatty acids on mammary SCD expression is scarce. We used a bovine mammary cell line (MAC-T) to assess the effect of acetic acid (Ac) and ß-hydroxybutyric acid (BHBA) in comparison with the effect of various long-chain fatty acids on the mRNA expression of the lipogenic enzymes SCD, acetyl-CoA carboxylase (ACACA), fatty acid synthase (FASN) and their associated gene regulatory proteins sterol regulatory element binding transcription factor 1 (SREBF1), insulin-induced gene 1 protein (INSIG1) and peroxisome proliferator-activated receptor alpha (PPARA)and peroxisome proliferator-activated receptor delta (PPARD) by quantitative real-time PCR. MAC-T cells were treated for 12 h without FA additions (CON) or with either 5 mM Ac, 5 mM BHBA, a combination of 5 mM Ac + 5 mM BHBA, 100 µM C16:0, 100 µM C18:0, 100 µM C18:1 cis-9, 100 µM C18:1 trans-11, 100 µM C18:2 cis-9,12 or 100 µM C18:3 cis-9,12,15. Compared with control, mRNA expression of SCD1 was increased by Ac (+61%) and reduced by C18:1 cis-9 (-61%), C18:2 cis-9,12 (-84%) and C18:3 cis-9,12,15 (-88%). In contrast to native bovine mammary gland tissue, MAC-T cells did not express SCD5. Expression of ACACA was increased by Ac (+44%) and reduced by C18:2 cis-9,12 (-48%) and C18:3 cis-9,12,15 (-49%). Compared with control, FASN expression was not significantly affected by the treatments. The mRNA level of SREBF1 was not affected by Ac or BHBA, but was reduced by C18:1 cis-9 (-44%), C18:1 trans-11 (-42%), C18:2 cis-9,12 (-62%) and C18:3 cis-9,12,15 (-68%) compared with control. Expression of INSIG1 was downregulated by C18:0 (-37%), C18:1 cis-9 (-63%), C18:1 trans-11 (-53%), C18:2 cis-9,12 (-81%) and C18:3 cis-9,12,15 (-91%). Both PPARA and PPARD expression were not significantly affected by the treatments. Our results show that Ac upregulated mRNA expression of SCD1 and ACACA in MAC-T cells. The opposite effect of the PUFA C18:2 cis-9,12 and C18:3 cis-9,12,15 on the these genes and the failure of Ac to mimic the PUFA-inhibited SREBF1 and INSIG1 mRNA expression, suggest that Ac can stimulate mammary lipogenesis via a transcriptional regulatory mechanism different from PUFA.
Relationship between milk fatty acid composition and the expression of lipogenic genes in the mammary gland of dairy cows
Mach Casellas, N. ; Goselink, R.M.A. ; Baal, J. van; Kruijt, L. ; Vuuren, A.M. van; Smits, M.A. - \ 2013
Livestock Science 151 (2013)1. - ISSN 1871-1413 - p. 92 - 96.
stearoyl-coa desaturase - nutritional regulation - lipid supplements - lactating cows - tissue - networks - protein
This study focussed on the complex regulation of lipid metabolism in the mammary gland of cows and the association between milk fatty acid (FA) profile and the expression of lipogenic genes in individual cows. Changes in FA profile were found to be accompanied by changes in the expression of regulatory genes related to a wide range of metabolic functions. Expression of most of key lipogenic genes and transcription factors such as peroxisome proliferator-activated receptor gamma (PPARG), and sterol regulatory element binding factor 1 (SREBP1) was mainly negatively correlated to the concentration of trans-FA and CLA isomers in milk. These correlations suggest that changes in ruminal lipid metabolism may result in modifications in the expression of lipid metabolism-related genes at mammary level.
Effector identification in the lettuce on Tight Junction Integrity: In Vitro Study in a Three Dimensional Intestinal Epithelial Cell Culture Model
Elamin, E. ; Jonkers, D. ; Juuti-Uusitalo, K. ; IJzendoorn, S. van; Troost, F. ; Duimel, H. ; Broers, J. ; Verheyen, F. ; Dekker, J. ; Masclee, A. - \ 2012
PLoS ONE 7 (2012)4. - ISSN 1932-6203
paracellular permeability - liver-disease - alcohol-consumption - induced increase - molecular-basis - leaky gut - barrier - tissue - monolayer - complex
Background: Intestinal barrier dysfunction and translocation of endotoxins are involved in the pathogenesis of alcoholic liver disease. Exposure to ethanol and its metabolite, acetaldehyde at relatively high concentrations have been shown to disrupt intestinal epithelial tight junctions in the conventional two dimensional cell culture models. The present study investigated quantitatively and qualitatively the effects of ethanol at concentrations detected in the blood after moderate ethanol consumption, of its metabolite acetaldehyde and of the combination of both compounds on intestinal barrier function in a three-dimensional cell culture model. Methods and Findings: Caco-2 cells were grown in a basement membrane matrix (Matrigel (TM)) to induce spheroid formation and were then exposed to the compounds at the basolateral side. Morphological differentiation of the spheroids was assessed by immunocytochemistry and transmission electron microscopy. The barrier function was assessed by the flux of FITC-labeled dextran from the basal side into the spheroids' luminal compartment using confocal microscopy. Caco-2 cells grown on Matrigel assembled into fully differentiated and polarized spheroids with a central lumen, closely resembling enterocytes in vivo and provide an excellent model to study epithelial barrier functionality. Exposure to ethanol (10-40 mM) or acetaldehyde (25-200 mu M) for 3 h, dose-dependently and additively increased the paracellular permeability and induced redistribution of ZO-1 and occludin without affecting cell viability or tight junction-encoding gene expression. Furthermore, ethanol and acetaldehyde induced lysine residue and microtubules hyperacetylation. Conclusions: These results indicate that ethanol at concentrations found in the blood after moderate drinking and acetaldehyde, alone and in combination, can increase the intestinal epithelial permeability. The data also point to the involvement of protein hyperacetylation in ethanol- and acetaldehyde-induced loss of tight junctions integrity.
Exposure to domoic acid through shellfish consumption in Belgium
Andjelkovic, M. ; Vandevijvere, S. ; Klaveren, J.D. van; Oyen, H. van; Loco, J. van - \ 2012
Environment International 49 (2012). - ISSN 0160-4120 - p. 115 - 119.
poisoning toxins - epidemiology - mussels - tissue - risk
A main known culprit causing amnesic shellfish poisoning in humans is domoic acid (DA). The toxin appearance in sea waters (by counting the toxin producing algae) and consequently in shellfish is closely monitored to prevent acute intoxications with gastrointestinal symptoms and neurological signs. However it is assumed that there might be some chronic problems with repetitive exposures to the toxin in animals. In humans this is greatly unknown and it is mostly assessed by relating reported toxin episodes and representative consumption data. Although in Belgium no alarming outbreaks have been reported in recent years, different concentrations of DA have been found in shellfish samples. In this study the human acute and chronic exposure to DA through shellfish consumption was evaluated by linking the data of DA concentrations in samples collected in the scope of the National Food control program in the period 2004-2009 and consumption data obtained from the National Belgian Food Consumption Survey including 3245 adults. The found level of toxin was highest in scallops while lowest in mussels. The mean usual long-term intake of molluscs such as scallops, mussels and oysters for the whole Belgian population was from 0.10 g/day for scallops to 1.21 g/day for mussels. With average portion size estimated to be 56-108 g/day depending on the shellfish source it was calculated that less than 1% of the population would be at risk of acute intoxication. Using a medium bound approach, 5-6% of the population shows chronic exposure exceeding the tolerable daily intake of 0.075 mu g/kg bw per day with scallops being the most probable toxin vector when using lower (68.5%) and medium (45.6%) bound concentrations.
G0/G1 switch gene-2 regulates human adipocyte lipolysis by affecting activity and localization of adipose triglyceride lipase
Schweiger, M. ; Paar, M. ; Eder, C. ; Brandis, J. ; Moser, E. ; Gorkiewisz, G. ; Grond, S. ; Radner, F.P.W. ; Cerk, I. ; Cornaciu, I. ; Oberer, M. ; Kersten, A.H. ; Zechner, R. ; Zimmermann, M.B. ; Lass, A. - \ 2012
Journal of Lipid Research 53 (2012). - ISSN 0022-2275 - p. 2307 - 2317.
hormone-sensitive lipase - chanarin-dorfman-syndrome - triacylglycerol catabolism - lysophosphatidic acid - messenger-rna - 2 g0s2 - protein - tissue - cgi-58 - disease
The hydrolysis of triglycerides in adipocytes, termed lipolysis, provides free fatty acids as energy fuel. Murine lipolysis largely depends on the activity of adipose triglyceride lipase (ATGL)5, which is regulated by two proteins annotated as comparative gene identification-58 (CGI-58) and G0/G1 switch gene-2 (G0S2). CGI-58 activates and G0S2 inhibits ATGL activity. In contrast to mice, the functional role of G0S2 in human adipocyte lipolysis is poorly characterized. Here we show that overexpression or silencing of G0S2 in human SGBS adipocytes decreases and increases lipolysis, respectively. Human G0S2 is upregulated during adipocyte differentiation and inhibits ATGL activity in a dose-dependent manner. Interestingly, C-terminally truncated ATGL mutants, which fail to localize to lipid droplets, translocate to the lipid droplet upon coexpression with G0S2 suggesting that G0S2 anchors ATGL to lipid droplets independent of ATGL's C-terminal lipid binding domain. Taken together, our results indicate that G0S2 also regulates human lipolysis by affecting enzyme activity and intracellular localization of ATGL. Increased lipolysis is known to contribute to the pathogenesis of insulin resistance and G0S2 expression has been shown to be reduced in poorly controlled type 2 diabetic patients. Our data indicate that downregulation of G0S2 in adipose tissue could represent one of the underlying causes leading to increased lipolysis in the insulin-resistant state.
Production of small starch granules by expression of a tandem-repeat of a family 20 starch-binding domain (SBD3-SBD5) in an amylose-free potato genetic background
Nazarian, F. ; Trindade, L.M. ; Visser, R.G.F. - \ 2012
Functional Plant Biology 39 (2012)2. - ISSN 1445-4408 - p. 146 - 155.
physical-properties - size - morphology - evolution - quality - growth - tissue - plants - tuber
Starch exists typically as semicrystalline granules of varying size. Granule size plays an important role for many industrial starch applications. Microbial non-catalytic starch binding domains (SBD) exhibit an affinity for starch granules on their own. Three different constructs were introduced in the amylose-free potato cultivar (Solanum tuberosum L. cv. amf) to investigate whether it is possible to produce smaller starch granules by an engineered, high-affinity, tandemrepeats of a family 20 starch-binding domain (SBD3, SBD4 and SBD5). A significant reduction in the size of starch granule was achieved in transgenic potato plants. Furthermore, it was shown that the SBDn expression can affect physical processes underlying granule assembly and the poorly understood granule formation. Expression of multiple linked SBDs resulted in amalgamated starch granules that consisted of many smaller granules. No significant alterations were observed with regard to rheological properties of starch granules.
Screening methods for the detection of antibiotic residues in slaughter animals: comparison of ther european union Four-Plate Test, the Nouws Antibiotic Test and the Premi Test (applied to muscle and kidney
Pikkemaat, M.G. ; Rapallini, M.L.B.A. ; Zuidema, T. ; Elferink, J.W.A. ; Oostra, S. ; Driessen, J.J.M. - \ 2011
Food Additives & Contaminants. Pt. A, Chemistry, Analysis, Control, Exposure & Risk Assessment 28 (2011)1. - ISSN 1944-0049 - p. 26 - 34.
antimicrobial residues - validation - tissue
Microbial growth inhibition tests are widely used as the primary screening approach for the detection of antibiotic residues in slaughter animals. In this study we evaluated and compared the performance of the European Union Four-Plate Test (EU4pt), the Nouws Antibiotic Test (NAT), and a commercial ampoule test, the Premi(R)Test (applied to both muscle and kidney), by parallel analysis of 735 slaughter animals. The EU4pt only showed significant inhibition with two muscle samples containing 305 mu g kg(-1) doxycycline and 648 mu g kg(-1) tulathromycin, while an maximum residue limit (MRL) violation of 1100 mu g kg(-1) sulfamethazine remained unnoticed. Premi(R)Test-muscle only detected the sulfamethazine containing sample, all other (1.1%) suspect samples appeared false-positive results. The same test applied to kidney yielded 4.1% suspect samples, while the NAT screening (based on analysis of renal pelvis fluid) showed 4.9% suspect results. The vast majority of these samples contained tetracycline and/or aminoglycoside residues. Premi(R)Test-kidney appeared to be more sensitive to aminoglycosides than the NAT screening, which failed to detect an MRL violation of 870 mu g kg(-1) gentamicin in kidney. Detection of less than MRL levels of tetracycline residues by the NAT proved its suitability for this residue group. Whether Premi(R)Test is sufficiently sensitive for accurate tetracycline detection in kidney remains doubtful, although changing over to kidney definitely improved the suitability of Premi(R)Test for the detection of residues in slaughter animals.
Septic Arthritis Caused by Legionella dumoffii in a Patient with Systemic Lupus Erythematosus-Like Disease
Flendrie, M. ; Jeurissen, S.M.F. ; Franssen, M. ; Kwa, D. ; Klaassen, C. ; Vos, F. - \ 2011
Journal of Clinical Microbiology 49 (2011)2. - ISSN 0095-1137 - p. 746 - 749.
pneumophila arthritis - culture - diagnosis - tissue - dna
We describe a patient with systemic lupus erythematosus (SLE)-like disease on immunosuppressive treatment who developed septic arthritis of the knee involving Legionella dumoffii. Cultures initially remained negative. A broad-range 16S PCR using synovial fluid revealed L. dumoffii rRNA genes, a finding that was subsequently confirmed by positive Legionella culture results.
Modeling cadmium in the feed chain and cattle organs
Fels-Klerx, H.J. van der; Romkens, P.F.A.M. ; Franz, E. ; Raamsdonk, L.W.D. van - \ 2011
Biotechnology, Agronomy, Society and Enviroment 15 (2011)Special issue 1. - ISSN 1370-6233 - p. 53 - 59.
dairy-cows - soil - kidney - tissue - liver
The objectives of this study were to estimate cadmium contamination levels in different scenarios related to soil characteristics and assumptions regarding cadmium accumulation in the animal tissues, using quantitative supply chain modeling. The model takes into account soil cadmium levels, soil pH, soil-to-plant transfer, animal consumption patterns, and transfer into animal organs (liver and kidneys). The model was applied to cattle up to the age of six years which were fed roughage (maize and grass) and compound feed. Cadmium content in roughage and cadmium intake by cattle were calculated for six different (soil) scenarios varying in soil cadmium levels and soil pH. For each of the six scenarios, the carry-over of cadmium from intake into the cattle organs was estimated applying two model assumptions, i.e., linear accumulation and a steady state situation. The results showed that only in the most extreme soil scenario (cadmium level 2.5 mg.kg-1, pH 4.5), cadmium exceeded the EC maximum tolerated level in roughage. Assuming linear accumulation, cadmium levels in organs of cattle up to six years of age, ranged from 0.37-4.03 mg.kg-1 of fresh weight for kidneys and from 0.07 to 0.77 mg.kg-1 of fresh weight for livers. The maximum tolerated levels in one or both organs were exceeded in several scenarios. When considering organ excretion of cadmium, internal cadmium levels in organs were approximately one order of magnitude lower as compared to the results of the linear accumulation model. In this case only in the most extreme soil scenario, the maximum tolerated level in the kidney was exceeded. It was concluded that the difference between the two assumptions (linear model versus a steady state situation to estimate cadmium carry-over in cattle) is negligible in the animal’s first five years of life, but will become relevant at higher ages. For the current case, the linear approach is a good descriptor for worst case situations. Furthermore, this study showed that quantitative supply chain modeling is an effective tool in assessing whether or not a specific combination of soil properties would lead to unacceptable contaminant levels in feedstuffs and animal products in the view of animal and human health.
Pancreas Protective Effect of Button Mushroom Agaricus bisporus (JE Lange) Imbach (Agaricomycetidae) Extract on Rats with Streptozotocin-Induced Dia betes
Yamac, M. ; Kanbak, G. ; Zeytinoglu, M. ; Senturk, H. ; Bayramoglu, G. ; Dokumacioglu, A. ; Griensven, L.J.L.D. van - \ 2010
International Journal of Medicinal Mushrooms 12 (2010)4. - ISSN 1521-9437 - p. 379 - 389.
antioxidant defense - diabetes-mellitus - oxidative stress - glucose toxicity - ergothioneine - prevalence - tissue - cells
In the present study we describe the effects of hot water extract of the culinary-medicinal button mushroom, Agaricus bisporus, on the symptoms of streptozotocin-induced diabetes in Sprague Dawley rats. A. bisporus extract at the doses of 0, 100, 200, and 400 mg/kg body weight (bw) per day were orally applied to streptozotocin-induced diabetic rats for a period of 7 days after the onset of the diabetes. Food and water intake and body weight were recorded daily. Upon sacrifice, histological studies were performed on pancreas tissues, and biochemical parameters such as glucose, insulin superoxide dismutase, malondialdehyde and catalase were measured of all experimental groups. The serum glucose levels significantly decreased after oral administration at the dose of 400 mg/kg bw per day by 29.68% with A. bisporus extract. Furthermore, the serum insulin levels in the streptozotocin-induced diabetic rats were increased to 78.50% at the extract dose of 400 mg/kg bw per day. Also, catalase activities and malondialdehyde levels decreased to values slightly above the normal animal control. The most obvious and surprising change was, however, the increase in cellularity of the Langerhans islets of the pancreas and their apparent repopulation with beta cells. We conclude that the oral application of high doses of A. bisporus extract may result in decreased severity of streptozotocin-induced diabetes in rat.
Deconjugation Kinetics of Glucuronidated Phase II Flavonoid Metabolites by B-glucuronidase from Neutrophils
Bartholomé, R. ; Haenen, G. ; Hollman, P.C.H. ; Bast, A. ; Dagnelie, P.C. ; Roos, D. ; Keijer, J. ; Kroon, P.A. ; Needs, P.W. ; Arts, I.C.W. - \ 2010
Drug Metabolism and Pharmacokinetics 25 (2010)4. - ISSN 1347-4367 - p. 379 - 387.
quercetin glucuronides - grain dust - inflammation - dietary - ph - tissue - cells - fluid - quercetin-4'-glucoside - quercetin-3-glucoside
Flavonoids are inactivated by phase II metabolism and occur in the body as glucuronides. Mammalian ß-glucuronidase released from neutrophils at inflammatory sites may be able to deconjugate and thus activate flavonoid glucuronides. We have studied deconjugation kinetics and pH optimum for four sources of ß-glucuronidase (human neutrophil, human recombinant, myeloid PLB-985 cells, Helix pomatia) with five flavonoid glucuronides (quercetin-3-glucuronide, quercetin-3'-glucuronide, quercetin-4'-glucuronide, quercetin-7-glucuronide, 3'-methylquercetin-3-glucuronide), 4-methylumbelliferyl-ß-D-glucuronide, and para-nitrophenol-glucuronide. All substrate-enzyme combinations tested exhibited first order kinetics. The optimum pH for hydrolysis was between 3.5-5, with appreciable hydrolysis activities up to pH 5.5. At pH 4, the Km ranged 44-fold from 22 µM for quercetin-4'-glucuronide with Helix pomatia ß-glucuronidase, to 981 µM for para-nitrophenol-glucuronide with recombinant ß-glucuronidase. Vmax (range: 0.735-24.012 µmol·min-1·unit-1 [1 unit is defined as the release of 1 µM 4-methylumbelliferyl-ß-D-glucuronide per min]) and the reaction rate constants at low substrate concentrations (k) (range: 0.002-0.062 min-1·(unit/L)-1 were similar for all substrates-enzyme combinations tested. In conclusion, we show that ß-glucuronidase from four different sources, including human neutrophils, is able to deconjugate flavonoid glucuronides and non-flavonoid substrates at fairly similar kinetic rates. At inflammatory sites in vivo the pH, neutrophil and flavonoid glucuronide concentrations seem favorable for deconjugation. However, it remains to be confirmed whether this is actually the case.
Longissimus muscle transcriptome profiles related to carcass and meat quality traits in fresh meat Pietrain carcasses
Pas, M.F.W. te; Keuning, E. ; Hulsegge, B. ; Hoving-Bolink, A.H. ; Evans, G. ; Mulder, H.A. - \ 2010
Journal of Animal Science 88 (2010)12. - ISSN 0021-8812 - p. 4044 - 4055.
skeletal-muscle - expression profiles - intramuscular fat - protein-synthesis - pigs - genes - tissue - kegg - hypertrophy - genomes
High quality pork is consumed as fresh meat while other carcasses are used in the processing industry. Meat quality is determined measuring technical muscle parameters. The objective of this research was to investigate the molecular regulatory mechanisms underlying meat quality differences of pork originating from genetically different Pietrain boars. Pietrain boars were approved for high meat quality using a DNA marker panel. Other Pietrain boars were indicated as average. Both groups produced litters in similar Pietrain sows. The longissimus muscles were sampled from nine carcasses produced by approved boars and eight carcasses of average boars. RNA was isolated and an equal portion of each sample was pooled to make a reference sample representing the mean of all samples. Each sample was hybridized on microarrays against the reference in duplicate using a dye swaps design. After normalization and subtraction of two times the background only genes expressed in at least five carcasses were analyzed. For all analyses the mean of the M-values relative to the reference, i.e. fold change, were used. Sixteen genes showed significant linear or quadratic associations between gene expression levels and meat color (Minolta a* value, Minolta L* value, reflection, pH 24 h) after Bonferroni correction. All these genes had expression levels similar to the reference in all carcasses. Studying association between gene expression levels and meat quality using only genes with expression statistically differing from the reference in at least five carcasses revealed 29 more genes associating with the technological meat quality parameters, again with meat color as a main trait. These associations were not significant after Bonferroni correction and explained less of the phenotypic variation in the traits. Bioinformatics analyses with DAVID using the list of genes with more than two-fold changed expression level revealed that these genes were mainly found in muscle-specific processes, protein complexes, and oxygen transport, and located to muscle-specific cellular localizations. Pathway analysis using the KEGG database revealed pathways related to protein metabolism, cellular proliferation, signaling, and adipose development differing between the two groups of carcasses. Approved meat carcasses showed less variation in gene expression. The results highlight biological molecular mechanisms underlying the differences between the high meat quality approved and average boars
1H-NMR study of the impact of high pressure and thermal processing on cell membrane integrity of onions
Gonzalez, M.E. ; Barrett, D.M. ; McCarthy, M.J. ; Vergeldt, F.J. ; Gerkema, E. ; Matser, A.M. ; As, H. van - \ 2010
Journal of Food Science 75 (2010)7. - ISSN 0022-1147 - p. E417 - E425.
spin-spin relaxation - mushrooms agaricus-bisporus - nuclear-magnetic-resonance - water diffusion - lactobacillus-plantarum - vacuolar symplast - osmotic-stress - maize roots - pfg-nmr - tissue
Proton nuclear magnetic resonance (1H-NMR) relaxometry was used to study the effects of high pressure and thermal processing on membrane permeability and cell compartmentalization, important components of plant tissue texture. High pressure treated onions were subjected to pressure levels from 20 to 200 MPa at 5 min hold time at initial temperatures of 5 and 20 °C. Thermally treated onions were exposed for 30 min at temperatures from 40 to 90 °C. Loss of membrane integrity was clearly shown by changes in transverse relaxation time (T2) of water at temperatures of 60 °C and above. Destabilization effects on membranes exposed to high pressure were observed at 200 MPa as indicated by T2 measurements and cryo-scanning electron microscopy (Cryo-SEM). T2 relaxation successfully discriminated different degrees of membrane damage based on the T2 shift of the vacuolar component. Analyses of the average water self-diffusion coefficient indicated less restricted diffusion after membrane rupture occurred in cases of severe thermal treatments. Milder processing treatments yielded lower average diffusion coefficients than the controls. 1H-NMR proved to be an effective method for quantification of cell membrane damage in onions and allowed for the comparison of different food processes based on their impact on tissue integrity
Functionality of cryopreserved juvenile ovaries from mutant mice in different genetic background strains after allotransplantation
Huang, K.Y. ; Groot, S.A. de; Woelders, H. ; Horst, G.T.J. van der; Themmen, A.P.N. ; Colenbrander, B. ; Fentener van Vlissingen, J.M. - \ 2010
Cryobiology 60 (2010)2. - ISSN 0011-2240 - p. 129 - 137.
in-vitro fertilization - adult-mouse ovaries - dna-repair enzyme - orthotopic transplantation - antral follicles - tissue - vitrification - oocytes - fertility - protein
The rapid expansion of mutant mouse colonies for biomedical research has resulted in lack of space at laboratory animal facilities and increasing risks of losing precious lines. These challenges require cheap and effective methods in addition to freezing embryos and sperm to archive the expanding mutant mouse lines. Cryopreservation of mouse ovarian tissue has been reported, but the application in the diverse mutant lines and genetic backgrounds has not yet been studied. In this study, juvenile ovaries (10-day-old) collected from genetically modified mouse lines were cryopreserved using high concentrations of cryoprotectants (dimethyl sulfoxide (Me(2)SO) and ethylene glycol (EG)) and instrumented ultra-rapid freezing. The validation of the frozen ovary batches was assessed by orthotopically transplanting a thawed ovary into a nearly completely ovariectomized mature female (congenic with the ovary donor). After 2 weeks of recovery, the ovary recipient was continuously paired with a male (congenic with the ovary donor) to evaluate the fertility of the recipient and delivered offspring were genotyped to evaluate the continued functionality of the grafted ovary. The recipient females delivered genetically modified offspring starting 6 weeks after ovary transplantation and lasting up to 6 months. The presented cryopreservation and transplantation protocols enabled retrieval of the genetic modification in 20 (from 22) genetically modified mutant mouse models on a C57BL/6 (17), FVB (2), or BALB/c (1) background. The thawed ovaries functioned after successful orthotopic allotransplantation to congenic wild-type recipients and produced mutant offspring, which allowed recreation of the desired genotype as a heterozygote on the proper genetic background. The results indicate that cryopreservation of mouse ovaries is a promising method to preserve genetic modification of the increasing number of mutant mouse models and can be used as a model for ovary cryopreservation using a variety of mouse mutants.
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