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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

In Vivo Effect Of Epilobium Hirsutum L. And Viscum Album L. On Protein And Mrna Expressions Of Rat Liver Vitamin D3 Metabolizing Cyp24a1 And Cyp27b1 Enzymes

Sever, Melike 01 September 2012 (has links) (PDF)
Epilobium hirsutum L. (Onagraceae) is a flowering, tall and perennial plant and native to Eurasia. It shows analgesic, anti-microbial and anti-proliferative activity, and it is used in our country as an alternative medicine. The pharmacological effect of Epilobium hirsutum L. could be explained by the presence of polyphenolics including steroids, tannins and flavonoids in the aerial parts. Viscum album L. (Loranthaceae) is a shrub that grows as an epiphyte on the branches of deciduous trees. It involves in the enhancement of macrophage phagocytic and cytotoxic mediated abilities as well as the strengthening the immune system. CYP24A1 and CYP27B1 are members of cytochrome P450 superfamily and the most important enzymes involved in the metabolism of vitamin D3. CYP27B1 and CYP24A1 are mitochondrial enzymes and also known as 25-hydroxyvitamin D3 1alpha-hydroxylase and 24-hydroxylase, respectively. CYP24A1 involves in 24-hydroxylation of 25-OH-D3 and 1,25-(OH)2D3 which is required for the catabolism of vitamin D3 compounds while CYP27B1 involves in 1&alpha / -hydroxylation of 25-OH-D3 into 1,25-(OH)2D3. In this study, in vivo effects of Epilobium hirsutum and Viscum album (subspecies growing on pine-trees-subsp. austriacum (Wiesb.) Vollmann) on rat liver CYP24A1 and CYP27B1 mRNA and protein expressions were investigated. To achieve this goal, 37.5 mg water extract of Epilobium hirsutum L./kg body weight/day was intraperitoneally injected to male rats for 9 days. To study the effect of Viscum album L., 10 mg water extract of Viscum album L./kg body weight/day was injected with the same conditions. After decapitation, livers were removed and S1.5 fractions were prepared. Effects of Epilobium hirsutum L. and Viscum album L. on rat liver mRNA and protein expressions were analyzed by qRT-PCR and western blotting, respectively. Epilobium hirsutum L. extract caused 31% and 18% decrease in rat liver CYP24A1 (p&lt / 0.0001) and CYP27B1 (p&lt / 0.05) protein expressions, respectively. The effect of Epilobium hirsutum L. on mRNA expression of CYP24A1 could not be observed, because CYP24A1 mRNA was almost undetectable in liver. Injection of Epilobium hirsutum L. to rats caused 2.7 fold increase in mRNA expression of CYP27B1 with respect to controls and normalized with GAPDH (Glyceraldehyde 3-phosphate dehydrogenase) expression as an internal reference (p&lt / 0.005). Viscum album L. caused 17% decrease in CYP24A1 protein expression (p&lt / 0.05). When rats injected with plant extract of Viscum album L., 18% decrease in CYP27B1 protein expression was observed (p&lt / 0.05). The effect of Viscum album L. on mRNA expression of CYP24A1 could not be observed since CYP24A1 mRNA was almost undetectable in liver. Injection of Viscum album L. to rats caused 3.8 fold increase in mRNA expression of CYP27B1 with respect to controls and normalized with GAPDH (Glyceraldehyde 3-phosphate dehydrogenase) expression as an internal reference (p&lt / 0.005). In conclusion, vitamin D3 metabolism may be affected by medicinal plants Epilobium hirsutum L. and Viscum album L. due to the changes in mRNA and protein expressions of CYP24A1 and CYP27B1 enzymes.
122

Regulation of tissue factor expression in myeloid and monocytic leukaemia cells

Tenno, Taavo January 2001 (has links)
Tissue factor (TF) is a transmembrane glycoprotein that initiates the blood coagulation cascade and is also involved in cell migration, tumour metastasis and angiogenesis. Pathologic expression of tissue factor by monocytes contributes to several thrombotic complications like acute coronary artery disease and disseminated intravascular coagulation. The aim of this thesis was to investigate the clinically important pathologic expression of TF in myelo-monocytic leukaemia cells and reveal the cellular signals leading to the suppression of TF expression. The studies in this thesis indicate that TF is a marker of immature myelo-monocytic cells. Markedly higher levels of TF were expressed in immature myelo-monocytic cell lines compared to mature monocyte-like cells. Induction of terminal differentiation in immature cells resulted in down-regulation of TF expression, irrespective of the specific phenotypes induced by retinoic acid (RA) or vitamin D3 in monoblastic U-937 cells. TF suppression was also found independent of differentiation pathways, i.e. monocytic or granulocytic. The nuclear receptor activation requirements for transcriptional suppression of TF by retinoic acid (RA) were shown to differ between acute promyelocytic leukaemia (APL) NB4 and U-937 cells. In NB4 cells the binding of the agonist to the RA receptor (RAR)α alone is needed for down-regulation of TF, whereas ligand binding to both RARαand retinoic X receptor was necessary for efficient suppression of TF expression in U-937 cells. To analyse the transcriptional regulation of TF, stable NB4 and U-937 clones expressing the luciferase gene under the control of various 5' flanking regions of the TF gene were selected. Different promoter regions were found to control the basal TF transcriptional activity. Analysis of protein binding to the 140 bp promoter region, responsible for basal TF activity in NB4 cells, revealed binding of RFX-1. RA suppressed the promoter activity in NB4, but not in U-937 cells. The ectopic expression of the APL fusion proteins PML/RARα or PLZF/RARα in U-937 reporter clones were shown to confer sensitivity to RA-induced suppression of TF promoter activity. These results provide a more detailed picture of TF regulation in leukaemic and haematopoietic cells and may have a bearing on new clinical treatment strategies in APL and other leukaemias.
123

Positron emission tomography of extra-striatal dopamine release

Gravel, Paul. January 2008 (has links)
Altered dopamine (DA) neurotransmission is implicated in neurological and psychiatric disorders. Positron Emission Tomography (PET) imaging of DA release has mainly been restricted to striatal areas, rich in D2/D 3 receptors, owing to the moderate affinity of the radioligands used. To measure extra-striatal DA release, where D2/D3 receptor concentrations are much smaller, an approach using a high affinity radioligand, such as [18F]Fallypride, is required. The aim of the present study was to investigate in healthy volunteers the suitability of [ 18F]Fallypride to measure variations in D2/D3 receptor occupancy, as a function of amphetamine-induced DA release, in extra-striatal regions. Six healthy male volunteers underwent two 18F-Fallypride PET sessions, following the double-blind oral administration of 0.3 mg/kg of d-amphetamine (Dexedrine) or placebo (lactose), counter-balanced for order. Following amphetamine administration, D2/D3 receptor occupancy of 18F-Fallypride was significantly reduced in striatum, but also in extra-striatal regions, including substantia nigra, amygdala, thalamus, hippocampus, and cortical areas.
124

Creating Interactive Visualizations for Twitter Datasets using D3

Björck, Olof January 2018 (has links)
Project Meme Evolution Programme (Project MEP) is a research program directed by Raazesh Sainudiin, Uppsala University, Sweden, that collects and analyzes datasets from Twitter. Twitter can be used to understand how ideas spread in social media. This project aims to produce interactive visualizations for datasets collected in Project MEP. Such interactive visualizations will facilitate exploratory data analysis in Project MEP. Several technologies had to be learned to produce the visualizations, most notably JavaScript, D3, and Scala. Three interactive visualizations were produced; one that allows for exploration of a Twitter user timeline and two that allows for exploration and understanding of a Twitter retweet network. The interactive visualizations are accessible as Scala functions and in a website developed in this project and uploaded to GitHub. The interactive visulizations contain some known bugs but they still allow for useful exploratory data analysis of Project MEP datasets and the project goal is therefore considered met. / Project Meme Evolution Programme
125

Efeito da suplementação de vitamina D3 (25-Hidroxicolecalciferol) na fase final sobre o cálcio sanguíneo e qualidade da carne em frangos de corte

Sanfelice, Cristiane [UNESP] 20 January 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-01-20Bitstream added on 2014-06-13T19:36:59Z : No. of bitstreams: 1 sanfelice_c_me_botfmvz.pdf: 528622 bytes, checksum: c9f0911ab04c1ca00ef2a724dcc79192 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / Foram realizados dois experimentos. No experimento 1, foi determinado qual das dosagens de vitamina 25-OHD3 promoveria a maior concentração de cálcio plasmático. Foram utilizados 90 frangos de corte e aos 35 dias, as aves foram suplementadas diariamente por sete dias com três dosagens de vitamina D3 na dieta. Todas as dietas continham 2.500UI de vitamina D3. O Tratamento 1, dieta controle, continha somente 2.500UI de vitamina D3/kg ração; o Tratamento 2 foi suplementado com 1.000UI de vitamina 25-OHD3, totalizando 3.500UI; o Tratamento 3, suplementado com 2.500UI de vitamina 25-OHD3, totalizando 5.000UI. A partir dos 42 dias todas as aves receberam a ração controle até os 48 dias de idade. Foram realizadas coletas de sangue, antes, durante e após a administração de vitamina D3 com coletas diárias dos 35-42 dias. O efeito dos níveis de cálcio foi testado de forma contínua por análise de regressão. Foram observadas diferenças ao longo dos dias de coleta de sangue, quanto maior os níveis de vitamina D3 suplementados na ração, maior foram as concentrações de cálcio plasmático. Conclui-se que a dose de 5.000UI de vitamina D, provocou maior concentração de cálcio sanguíneo. No experimento 2, foi avaliado qual o melhor tempo de administração de vitamina D3 antes do abate para se obter níveis elevados de cálcio plasmático por pelo menos dois dias após a última administração. Foram utilizados 60 frangos de corte e aos 35 dias as aves foram suplementadas com vitamina D3 na dieta com a melhor dosagem obtida no experimento 1... / Two trials were conducted. In trial 1, there was determine which dosage of vitamin 25-OHD3 would promoted the highest plasma calcium concentration. There were housed 90 broiler chickens and at 35 days of age, the birds were supplemented daily for seven days with three doses of vitamin D in the diet. All diets contained 2.500UI of vitamin D3. The treatment 1, control diet, contained only 2.500UI D3/kg vitamin in diet; the treatment 2 was supplemented with 1,000UI of 25-OHD3 vitamin, totaling 3.500UI; Treatment 3, was supplemented with 2,500UI of 25-OHD3, totaling 5.000UI. From 42 days all birds received the control diet until 48 days old. Blood samples were collected, before, during and after the administration of vitamin D3 with daily collects in the 35-42 days. The calcium levels effect was continuously tested by regression analysis. There were differences day of blood collection, and the higher levels of 25-OHD3 vitamin supplementation in the diet were higher concentrations of plasma calcium. It is concluded that the dosage of 5,000UI vitamin D3, caused the highest calcium concentration. In experiment 2 there was evaluated the best administration time of vitamin D3 before slaughter to obtain high levels of plasma calcium by at least two days after the last administration. There were housed 60 broilers chickens and at 35 days of age, the birds were supplemented with vitamin 25-OHD3 in the diet with the best dosage obtained in experiment 1, was evaluated in three periods of administration, T1: 3 days, T2: 5 days, T3: 7 consecutive days of administration of the final diet supplemented. After each period of feed, the birds received control diet for four consecutive days. Daily, blood samples were collected, before, during and after the last administration. The plasma calcium in birds fed for five consecutive days... (Complete abstract click electronic access below)
126

Le récepteur Aryl hydrocarbon au niveau de la barrière hémato-encéphalique : implication dans la régulation de l'expression de ABCB1, ABCG2 et du CYP1B1 / The aryl hydrocarbon receptor at the human blood-brain barrier : implication in the regulation of ABCB1, ABCG2 and CYP1B1 expression

Jacob, Aude 03 October 2012 (has links)
Les principaux transporteurs ABC et cytochromes P450 exprimés au niveau des microvaisseaux cérébraux chez l’homme sont l’ABCB1/P-gp, l’ABCG2/BCRP et le CYP1B1. Au niveau des organes périphériques, la régulation de l’expression de ces trois marqueurs fait intervenir des facteurs de transcription et notamment le récepteur aryl hydrocarbon (AhR). Or les transcrits d’AhR sont très exprimés au niveau des microvaisseaux cérébraux humains. Les travaux de cette thèse ont donc dans un premier temps été consacrés à l’étude de l’implication de la voie du récepteur Ah dans la régulation de l’expression de l’ABCB1, de l’ABCG2 et du CYP1B1 au niveau de la barrière hémato-encéphalique. In vivo, nous avons mis en évidence qu’un traitement aigu par la dioxine (ou TCDD), ligand puissant d’AhR, induisait l’expression génique et protéique du Cyp1b1 au niveau des microvaisseaux cérébraux de rats adultes Srague-Dawley. De même, in vitro, l’exposition au TCDD a fortement induit l’expression du CYP1B1 dans la lignée hCMEC/D3, un modèle in vitro de l’endothélium cérébral humain et le recours à la technique de l’ARN interférence nous a permis de démontrer que le récepteur Ah était impliqué dans les effets observés. En revanche, que ce soit in vivo ou in vitro, l’exposition au TCDD n’a entrainé aucune modification significative de l’expression de l’ABCB1 ou de l’ABCG2. Dans un second temps, nous avons étudié l’interrelation entre la voie AhR et les voies de réponse à l’hypoxie cellulaire. Les différentes expériences réalisées sur la lignée cellulaire hCMEC/D3 ont mis en évidence une interaction non réciproque entre ces deux voies de signalisation : en cas d’activation simultanée, la réponse à l’hypoxie abolit la réponse AhR tandis que l’activation de la voie AhR ne modifie pas la réponse adaptative à l’hypoxie. / ABCB1 (P-gp), ABCG2 (BCRP) and CYP1B1 are the main ABC transporters and cytochrome P450 enzymes expressed at the human blood-brain barrier (BBB). In peripheral tissue, expression of these proteins is regulated by transcription factors such as the aryl hydrocarbon receptor (AhR). Interestingly, high levels of AhR mRNA are detected in human brain microvessels. We therefore investigated the potential implication of AhR in the regulation of ABCB1, ABCG2 and CYP1B1 expression. In vivo, a single dose of TCDD, a highly potent AhR ligand, increased Cyp1b1 transcripts and protein expression in rat brain microvessels. Similarly, exposing hCMEC/D3 cells, an in vitro promising model of human BBB, to TCDD induced CYP1B1 expression. Using small interfering RNA, we established AhR involvement in TCDD effects. However, either in vivo or in vitro TCDD treatment had no effect on ABCB1 or ABCG2 expression. Next, we investigated the crosstalk between AhR and hypoxia signalling pathways in case of simultaneous activation. Our experiments revealed that a crosstalk between these two pathways effectively occurred in hCMEC/D3 cells: hypoxia inhibited AhR response but not the reverse.
127

Visualisering av geospatialdata från firms i heatmaps : En jämförelse av visualiseringstekniker med D3.js och Heatmap.js baserat på utritningstid / Visualization of geospatialdata from firms in heatmaps : A comparison of visualization techniques with D3.js and Heatmap.js based on plotting time

Abrahamsson, Viktor January 2020 (has links)
Stora mängder miljödata samlas hela tiden in och för att använda all data behöver den förstås av användarna så de kan applicera kunskapen inom deras område. Visualisering skapar förståelse om data. Heatmaps kan användas för att visualisera geospatial data och interaktivitet är ett hjälpmedel för att skapa ytterligare grafiska representationer. I detta arbete evalueras JavaScript-teknikerna D3.js, Heatmap.js och Vue.js angående vad som är mest lämpligt för att visualisera geospatial data utifrån effektiviteten vid utritning av heatmaps. Ett experiment genomförs där biblioteken D3.js, Heatmap.js testas i ramverket Vue.js. Detta för att ta reda på vilket bibliotek som föredras vid utritning av heatmaps och om ett ramverk påverkar resultatet. En miljö sätts upp för att genomföra undersökningen och tester för att påvisa detta. Resultatet indikerar att Heatmap.js och mindre datamängder ger en lägre utritningstid i den tillämpning som undersökts. I framtiden är det intressant att undersöka flera bibliotek och flera datamängder.
128

Role of Protein Kinase C Isotypes in 1,25-Dihydroxyvitamin D3 Mediated Signal Transduction Through the 1,25D3 Membrane Associated, Rapid Response Steroid Binding Receptors in Chick Intestinal Cells

Tunsophon, Sakara 01 May 2010 (has links)
It is now accepted that 1,25(OH)2D3 mediates its rapid actions on the control of phosphate and calcium homeostasis through its membrane receptor termed the 1,25D3-MARRS (membrane associated rapid response steroid binding) protein. I determined the various PKC isotypes involved in the rapid regulation of phosphate uptake and calcium extrusion in chick intestinal cells. 1,25(OH)2D3-mediated phosphate uptake was stimulated within 1 min after addition of the hormone. Western blot analyses on isolated intestinal cells treated with steroid hormone resulted in dose-dependent increases in PKC alpha and PKC beta in postnuclear centrifugation fractions, but not in the low speed centrifugation fractions. The highest immunoreactivity of PKC alpha was found after treatment of the cells with 300 pM 1,25(OH)2D3 and declined at 650 pM hormone, relative to corresponding controls, while the highest immunoreactivity of PKC beta was found in cells treated with either 300 pM or 650 pM 1,25(OH)2D3. Therefore, PKC alpha and PKC beta redistribution are likely to relate to the dose-response curve for both phosphate uptake and calcium efflux, respectively. Using transfection of primary cultures of intestinal cells with siRNA for these two isotypes, I found decreased 32P uptake in cells transfected with siRNA to either PKC alpha or PKC beta in both controls (relative to untransfected controls), and hormone-treated cells. Further study of the effect of chemical blockers for PKC alpha or PKC beta on phosphate uptake was conducted in suspensions of isolated intestinal cells. The results from these experiments also confirmed the findings from the siRNA experiments and demonstrated decreased 32P uptake in cells treated with 1,25(OH)2D3 plus blockers in comparison with cells treated with 1,25(OH)2D3 alone. The effects of PKC alpha and PKC beta in steroid-mediated calcium extrusion were further investigated using siRNA for PKC alpha or PKC beta. We found the siRNA to PKC beta alone caused decreased calcium extrusion. We also found that the inhibitors of PKC beta, but not PKC alpha caused significantly enhanced calcium uptake by decreasing calcium efflux from the cells. This result suggested that PKC beta might be involved in the rapid response of 1,25(OH)2D3-stimulated calcium extrusion. I used confocal microscopy to study the redistribution of PKC alpha and PKC beta in cells exposed to steroid hormone for 30 sec. PKC alpha was found to increase significantly in the apical membrane after a 30 sec exposure of cells to 300- or 650 pM 1,25(OH)2D3. By comparison, anti-PKC beta immunofluorescence was found to increase significantly in the basal region of cells, relative to controls, following exposure of cells to 300 pM seco-steroid. These combined results, lead me to conclude the involvement of both PKC alpha and PKC beta in the signal transduction mechanism of 1,25(OH)2D3-mediated phosphate uptake while PKC beta is involved in the mechanism of 1,25(OH)2D3-mediated calcium efflux in chick intestinal epithelial cells.
129

Rapid Actions of 1,25-Dihydroxyvitamin D<sub>3</sub> on Phosphate Uptake in Isolated Chick Intestinal Cells

Zhao, Bin 01 May 2002 (has links)
1,25-dihydroxyvitamin D3 [1,25(0H)2D3] has been shown to promote phosphate transport rapidly in the perfused duodenal loop, relative to controls, reaching treated/av basal at T = 40 min = 1.82 ± 0.42 and 1.11 ± 0.21, respectively. By using isolated chick enterocytes, studies were undertaken to determine whether 1,25(0H)2D3 has a direct effect on isolated intestinal cells that is manifested by either enhanced uptake or extrusion of phosphate. In time course studies, with 4- to 8-wk-old chicks, 32P uptake in enterocytes at 10 min after addition of test substance was 0%, 130%, 151%, and 123% of controls for 10 pM, 50 pM, 130 pM, and 300 pM 1,25(0H)2D3, respectively. The metabolite 24,25- dihydroxyvitamin D3 [24,25(0H)2D3] exerted an inhibitory effect on phosphate uptake by 1,25(0H)2D3 at a concentration of 130 pM. This result was in agreement with perfusion studies and supports the physiological relevance of isolated cell studies. For signal transduction studies, isolated enterocytes were incubated with 20 µM forskolin (an activator of protein kinase A), 100 nM phorbol ester (an activator of protein kinase C), or 2 µM BAY K 8644 (a calcium channel activator). Enhanced 32P levels relative to controls were found for phorbol ester (126% of controls at T = 7 min, P < 0.05) and BAY K 8644 (150% of controls at T = 7 min, P < 0.05) but not for forskolin, suggesting involvement of protein kinase C and calcium channel signal transduction pathways in uptake. These results paralleled those observed for the perfused duodenal loop. For aging studies, white leghorn roosters were raised for 7, 14, and 28 wk prior to experiments. These studies showed a 1,25(0H)2D3-mediated increase in 32P uptake in isolated cells at 7 wk, but not at 14 or 28 wk. Further analysis of isolated basal lateral membrane (BLM) on SDS-PAGE followed by Western analysis with a well characterized antibody (Ab099) showed a decreased expression of the putative membrane receptor for 1,25(0H)2D3 with increasing age, paralleling the results obtained for 32P uptake in isolated intestinal cell studies. Analyses of 1,25(0H)2D3 effect on protein kinase C activity likewise revealed hormone-mediated stimulation in cells from 7-wk- old chicks, with decreasing responsiveness at a later age. The combined results indicate a physiologically important role for 1,25(0H)2D3 membrane-initiated phosphate uptake in enterocytes of young, rapidly growing animals. Furthermore, these studies validate the use of isolated intestinal cells for further studies on ribozyme-mediated ablation of the 1,25(0H)2D3 membrane receptor function.
130

Visualisering av miljödata i form av heatmaps : En jämförelsestudie mellan utritningsteknikerna Canvas och SVG baserat på utritningstiden / Visualization of environmental data in the form of heatmaps : A comparison study between the rendering technology Canvas and SVG based on the rendering time

Falck, Fanny January 2023 (has links)
Det samlas in olika typer av data hela tiden, komplex data är svårt för människor att tolka och förstå i dess råa form. För att göra det lättare för människor använder man olika datavisualiseringsverktyg som gör det lättare att sammanfatta data. Det finns många olika typer av visualiseringar som till exempel diagram, tabeller, bilder och kartor såsom en Heatmap. En heatmap används för att visa geospatial data, då den använder koordinater kombinerat med en karta som visar aktiviteterna genom olika färger. Ett problem som uppstår när komplex data används är att utritningstiden brukar vara långsam, detta leder till att användarupplevelsen försämras. I detta arbete ska två tekniker jämföras för att ta reda på vilken teknik som kan visualisera miljödata i form av heatmap på snabbaste tid med kartlagret Google Maps, med data som kommer ifrån ICES Oceanographic databas som klassificeras som miljödata. Tekniken som ska jämföras är Canvas som representeras av JavaScript biblioteket Heatmap.js och SVG som representeras av JavaScript biblioteket D3.js För att utföra denna studie användes ett tekniskt experiment som vald vetenskaplig metod. Resultatet av studien blev att Heatmap.js presterade bättre än vad D3.js gjorde.

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