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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.
1

Mikrobiální aktivity půdy ovlivněné různou mírou kontaminace ropnými uhlovodíky

Dvořáčková, Helena January 2014 (has links)
Bioremediation is a method of reviving enviroment which is using natural processes. These processes, the modern technology is trying to make faster and more effective. This diploma thesis deals with a theme about Microbial Activity of Soil influenced by different measurements of crude oil hydrocarbon contamination and observing of microbial consorcia activity in contamined, not contamined and sterile soil. The initial chapter deals with crude oil contamination and bacterial metabolism which is able to remove this contamination. There was executed a container trial in the experimental part of this thesis. The plants were planted into different types of adjusted soil (crude oil application, sterilization and so on). There was compared a production of biomass and there are a few conclusion from these results. The elementary thing is that the soil micro-organisms which appear in oil soil can make a life strategy in this enviroment and can also prosper which reflects on the production of biomass.The container trial was determined as the most exact method of soil activity valuation because it is nearest to the real soil proportion. Followingly there were executed analysis of store soil and analysis of so after finishng of the container trial. These results brought similar conclusions, however the cultivation on nutrient soil and the cultivation like that it is not comparable. The store soil underwent a water cress trial. This trial confirmed toxic effects of crude oil but it also showed the fact that crude oil is a natural substance and micro-organisms can adapt to it. The mineralization of soil was measured with help of ionic measurers.
2

Vliv dotace mikroprvků u masného skotu na parametry užitkovosti a koncentraci mikroprvků v krvi telat

Kořínek, Matěj January 2016 (has links)
Aim of this thesis was to evaluate influence of inorganic selenium given, in a form of mineral supplement compound, to cows and their calves in order to supply their organism with selenium and also for the utilitarian traits. These were divided into two groups of six and supplemented with two different forms of selenium: group A was given inorganic sodium selenite, group B was given organic selenomethionine. Cows that were examined before the start of supplementation had average activity GPX in blood samples from group A 847,06 +- 170,77 ukat/l and group B 791,30 +- 91,20 ukat/l and concentration of Se of group A: 136,70 +- 27,97 ug/l and group B 95,77 +- 20,05 ug/l. It was found that cows postpartum had higher activity of GPx by 26% in group A and by 45% in group B. Difference between groups was statistically inconclusive (p < 0,28). Increase in concentration of selenium in blood of cows in group A was 7,5% and in group B 5%. In blood of newborn calves of both groups was not found conclusive difference of GPx (p < 0,43). Concentration of selenium in group calves A 160,18 +- 18,07 ug/l and group B 105,30 +- 24,26 ug/l. Difference in concentration of selenium in blood of cows and calves was statistically conclusive (p < 0,05), but because this difference was conclusive already before the supplement compound was given both inorganically and organically bound selenium, this result cannot be interpreted as conclusive influence of different forms of selenium supplemented. Weight and weight gain of calves were balanced between groups and statistically did not differ (p < 0,39). It can be concluded that both forms of selenium had analogical biological effect on focused parameters.In blood of newborn calves no conclusive difference in GPx was found
3

Studium některých aspektů N metabolismu u sóji ve vztahu k tvorbě výnosu a jeho některým kvalitativním ukazatelům

Phuong, Nguyen Thi January 1991 (has links)
No description available.
4

Protein kinase D3 signaling in the regulation of liver metabolism / Proteinkinase D3 Signalwirkung in der Regulation des Leberstoffwechsels

Mayer, Alexander E. January 2021 (has links) (PDF)
The liver plays a pivotal role in maintaining energy homeostasis. Hepatic carbohydrate and lipid metabolism are tightly regulated in order to adapt quickly to changes in nutrient availability. Postprandially, the liver lowers the blood glucose levels and stores nutrients in form of glycogen and triglycerides (TG). In contrast, upon fasting, the liver provides glucose, TG, and ketone bodies. However, obesity resulting from a discrepancy in food intake and energy expenditure leads to abnormal fat accumulation in the liver, which is associated with the development of hepatic insulin resistance, non-alcoholic fatty liver disease, and diabetes. In this context, hepatic insulin resistance is directly linked to the accumulation of diacylglycerol (DAG) in the liver. Besides being an intermediate product of TG synthesis, DAG serves as second messenger in response to G-protein coupled receptor signaling. Protein kinase D (PKD) family members are DAG effectors that integrate multiple metabolic inputs. However, the impact of PKD signaling on liver physiology has not been studied so far. In this thesis, PKD3 was identified as the predominantly expressed isoform in liver. Stimulation of primary hepatocytes with DAG as well as high-fat diet (HFD) feeding of mice led to an activation of PKD3, indicating its relevance during obesity. HFD-fed mice lacking PKD3 specifically in hepatocytes displayed significantly improved glucose tolerance and insulin sensitivity. However, at the same time, hepatic deletion of PKD3 in mice resulted in elevated liver weight as a consequence of increased hepatic lipid accumulation. Lack of PKD3 in hepatocytes promoted sterol regulatory element-binding protein (SREBP)-mediated de novo lipogenesis in vitro and in vivo, and thus increased hepatic triglyceride and cholesterol content. Furthermore, PKD3 suppressed the activation of SREBP by impairing the activity of the insulin effectors protein kinase B (AKT) and mechanistic target of rapamycin complexes (mTORC) 1 and 2. In contrast, liver-specific overexpression of constitutive active PKD3 promoted glucose intolerance and insulin resistance. Taken together, lack of PKD3 improves hepatic insulin sensitivity but promotes hepatic lipid accumulation. For this reason, manipulating PKD3 signaling might be a valid strategy to improve hepatic lipid content or insulin sensitivity. However, the exact molecular mechanism by which PKD3 regulates hepatocytes metabolism remains unclear. Unbiased proteomic approaches were performed in order to identify PKD3 phosphorylation targets. In this process, numerous potential targets of PKD3 were detected, which are implicated in different aspects of cellular metabolism. Among other hits, phenylalanine hydroxylase (PAH) was identified as a target of PKD3 in hepatocytes. PAH is the enzyme that is responsible for the conversion of phenylalanine to tyrosine. In fact, manipulation of PKD3 activity using genetic tools confirmed that PKD3 promotes PAH-dependent conversion of phenylalanine to tyrosine. Therefore, the data in this thesis suggests that PKD3 coordinates lipid and amino acid metabolism in the liver and contributes to the development of hepatic dysfunction. / Die Leber spielt eine zentrale Rolle bei der Aufrechterhaltung der Energiehomöostase. Der hepatische Kohlenhydrat- und Fettstoffwechsel ist stark reguliert, um sich schnell an Veränderungen in der Nährstoffverfügbarkeit anzupassen. Die Leber senkt postprandial den Blutzuckerspiegel und speichert Nährstoffe in Form von Glykogen und Triglyzeriden (TG). Im Gegensatz dazu stellt die Leber beim Fasten Glukose, TG und Ketonkörper bereit. Fettleibigkeit, welche aus einer Diskrepanz zwischen Nahrungsaufnahme und Energieaufwand resultiert, führt allerdings zu einer abnormalen Fettansammlung in der Leber, die mit der Entwicklung von Leberinsulinresistenz, nicht-alkoholischen Fettlebererkrankungen und Diabetes einhergeht. Hepatische Insulinresistenz steht dabei in direktem Zusammenhang mit der Akkumulation von Diacylglycerol (DAG) in der Leber. DAG ist nicht nur ein Zwischenprodukt der TG-Synthese, sondern dient auch als sekundärer Messenger im G-Protein-gekoppelten Rezeptor-Signalweg. Die Mitglieder der Proteinkinase D (PKD)-Familie sind DAG-Effektoren, die vielfache metabolische Inputs integrieren. Jedoch wurden die Auswirkungen der PKD-Signalwirkung auf die Leberphysiologie bisher nicht untersucht. Im Rahmen dieser Thesis wurde PKD3 als die in der Leber überwiegend exprimierte Isoform identifiziert. Die Stimulation von primären Hepatozyten mit DAG sowie die Fütterung von Mäusen mit fettreicher Nahrung (HFD) führte zu einer Aktivierung von PKD3, was auf eine Relevanz von PKD3 bei Fettleibigkeit hinweist. Mäusen, welchen PKD3 spezifisch in Hepatozyten fehlte und mit HFD gefüttert wurden, zeigten eine deutlich verbesserte Glukosetoleranz und Insulinsensitivität. Gleichzeitig führte jedoch die hepatische Deletion von PKD3 bei Mäusen zu einem erhöhten Lebergewicht in Folge einer erhöhten Lipidakkumulation in der Leber. Das Fehlen von PKD3 in Hepatozyten förderte die Sterol Regulatory Element-Binding Protein (SREBP)-vermittelte de novo Lipogenese in vitro und in vivo und erhöhte damit den Gehalt an Triglyceriden und Cholesterol in der Leber. Darüber hinaus supprimierte PKD3 die Aktivierung von SREBP, indem es die Aktivität der Insulin-Effektoren Proteinkinase B (AKT) und mechanistisches Ziel von Rapamycin- Komplexen (mTORC) 1 und 2 verminderte. Im Gegensatz dazu förderte die leberspezifische Überexpression von konstitutiv aktiver PKD3 die Glukoseintoleranz und Insulinresistenz. Zusammenfassend verbessert der Mangel an PKD3 die hepatische Insulinempfindlichkeit, aber fördert gleichzeitig die Akkumulation von Lipiden in der Leber. Aus diesem Grund könnte das Eingreifen in den PKD3-Signalweg eine gute Strategie zur Verbesserung des hepatischen Lipidgehalts oder der Insulinempfindlichkeit sein. Allerdings bleibt der genaue molekulare Mechanismus, mit dem PKD3 den Stoffwechsel von Hepatozyten reguliert, unklar. Es wurden unvoreingenommene proteomische Ansätze durchgeführt, um PKD3- Phosphorylierungsziele zu identifizieren. In diesem Prozess wurden zahlreiche potenzielle Ziele von PKD3 entdeckt, welche in den verschiedensten Aspekten des Zellstoffwechsels involviert sind. Unter anderem wurde Phenylalaninhydroxylase (PAH) als Ziel von PKD3 in Hepatozyten identifiziert. PAH ist das Enzym, welches für die Umwandlung von Phenylalanin in Tyrosin verantwortlich ist. Tatsächlich bestätigte die Manipulation der PKD3-Aktivität mit Hilfe von genetischen Werkzeugen, dass PKD3 die PAH-abhängige Umwandlung von Phenylalanin in Tyrosin fördert. Deswegen legen die Daten in dieser Arbeit nahe, dass PKD3 den Lipid- und Aminosäurestoffwechsel in der Leber koordiniert und zur Entwicklung von Leber- Dysfunktion beiträgt.
5

Studium metabolismu dihydromyricetinu / The Study of metabolism of dihydromyricetin

Blecha, Tomáš January 2017 (has links)
More attention has recently been paid to the chemopreventive compounds contained in food of plant origin. A large group of chemopreventive compounds are represented by flavonoids contained in many dietary supplements. One of the representatives of this group is dihydromyricetin, which is attributed to positive impact on human organism, in particular by its antioxidant, anti-inflammatory and hepatoprotective effects. Some flavonoids can act as modulators of enzymes of phase I and phase II metabolism of xenobiotics biotransformation by their inhibition or induction which can causean interference with endogenous metabolism. In first part of this present work, the effect of selected flavonoid compounds, such as biochanin A, dihydromyricetin, myricetin and their combinations on the gene expression of cytochrome P450 2E1 (CYP2E1) and sulfotransferases 1A1 (SULT1A1) in liver and small intestine of laboratory rats was studied. The small intestine was divided into three parts namely a proximal, middle and distal. At first, isolation of total RNA was made followed by conversion into cDNA using random hexamers as primers. By real-time PCR a significant decrease in gene expression of both enzymes in liver was found. The highest induction of gene expression was observed for both enzymes in proximal part of...
6

Regulation of the Mevalonate Pathway by the Deubiquitinase USP28 in Squamous Cancer / Regulation des Mevalonat Stoffwechselwegs durch die Deubiquitinase USP28 in Plattenepithelkarzinomen

Maier [verh. Hartmann], Carina Ramona January 2024 (has links) (PDF)
The reprogramming of metabolic pathways is a hallmark of cancer: Tumour cells are dependent on the supply with metabolites and building blocks to fulfil their increased need as highly proliferating cells. Especially de novo synthesis pathways are upregulated when the cells of the growing tumours are not able to satisfy the required metabolic levels by uptake from the environment. De novo synthesis pathways are often under the control of master transcription factors which regulate the gene expression of enzymes involved in the synthesis process. The master regulators for de novo fatty acid synthesis and cholesterogenesis are sterol regulatory element-binding proteins (SREBPs). While SREBP1 preferably controls the expression of enzymes involved in fatty acid synthesis, SREBP2 regulates the transcription of the enzymes of the mevalonate pathway and downstream processes namely cholesterol, isoprenoids and building blocks for ubiquinone synthesis. SREBP activity is tightly regulated at different levels: The post-translational modification by ubiquitination decreases the stability of active SREBPs. The attachment of K48-linked ubiquitin chains marks the transcription factors for the proteasomal degradation. In tumour cells, high levels of active SREBPs are essential for the upregulation of the respective metabolic pathways. The increased stability and activity of SREBPs were investigated in this thesis. SREBPs are ubiquitinated by the E3 ligase Fbw7 which leads to the subsequential proteolysis of the transcription factors. The work conducted in this thesis identified the counteracting deubiquitination enzyme USP28 which removes the ubiquitin chains from SREBPs and prevents their proteasomal degradation. It further revealed that the stabilization of SREBP2 by USP28 plays an important role in the context of squamous cancers. Increased USP28 levels are associated with a poor survival in patients with squamous tumour subtypes. It was shown that reduced USP28 levels in cell lines and in vivo result in a decrease of SREBP2 activity and downregulation of the mevalonate pathway. This manipulation led to reduced proliferation and tumour growth. A direct comparison of adenocarcinomas and squamous cell carcinomas in lung cancer patients revealed an upregulation of USP28 as well as SREBP2 and its target genes. Targeting the USP28-SREBP2 regulatory axis in squamous cell lines by inhibitors also reduced cell viability and proliferation. In conclusion, this study reports evidence for the importance of the mevalonate pathway regulated by the USP28-SREBP2 axis in tumour initiation and progression of squamous cancer. The combinatorial inhibitor treatment of USP28 and HMGCR, the rate limiting enzyme of the mevalonate pathway, by statins opens the possibility for a targeted therapeutic treatment of squamous cancer patients. / Die Reprogrammierung metabolischer Stoffwechselwege ist ein Kennzeichen von Krebs: Tumorzellen sind abhängig von der Versorgung mit Metaboliten und Bausteinen, um ihren wachsenden Bedarf als hoch proliferierende Zellen zu decken. Vor allem die de novo Stoffwechselsynthesewege sich hochreguliert, wenn die Zellen des wachsenden Tumors nicht mehr in der Lage sind, ihr erforderliches metabolisches Niveau mithilfe der Aufnahme aus der Umgebung zu erfüllen. De novo Synthesewege sind oft unter der Kontrolle von zentralen Transkriptionsfaktoren die die Genexpression von Enzymen, die im Syntheseprozess beteiligt sind, regulieren. Die vorherrschenden Regulatoren, für die de novo Fettsäuresynthese und der Cholesterogenese sind die Steroid-regulatorisches-Element-bindende Proteine (SREBPs). Während SREBP1 bevorzugt die Expression von Enzymen die an der Fettsäuresynthese beteiligt sind kontrolliert, reguliert SREBP2 die Transkription von Enzymen des Mevalonat Stoffwechselwegs, sowie Prozesse unterhalb, namentlich die Cholesterol-, Isoprenoid- und die die Synthese von Bausteinen für die Ubiquinonsynthese. Die Aktivität von SREBP ist streng reguliert auf verschiedenen Ebenen: Die post-translationale Modifikation mittels Ubiquitinierung reduziert die Stabilität von aktiven SREBPs. Das Anhängen von K48-verlinkten Ubiquitinketten markiert die Transkriptionsfaktoren für den proteasomalen Abbau. In Tumorzellen sind hohe Niveaus von aktiven SREBPs essentiell für die Induktion der entsprechenden metabolischen Stoffwechselwege. Die erhöhte Stabilität und Aktivität von SREBPs wurden im Rahmen dieser Arbeit untersucht. SREBPs werden von der E3-Ligase Fbw7 ubiquitiniert, was zur Proteolyse der Transkriptionsfaktoren führt. In dieser Arbeit wurde gezeigt, dass das entgegenwirkende Deubiquitinierungsenzym USP28 die Ubiquitinketten von SREBPs entfernt und deren proteasomalen Abbau verhindert. Diese Forschungsarbeit zeigt weiterhin, dass die Stabilisierung von SREBP2 durch USP28 eine wichtige Rolle im Kontext von Epithelkarzinomen spielt. Erhöhte USP28 Niveaus werden mit einem schlechten Überleben von Patienten in der Krebs-Untergruppe der Plattenepithelkarzinomen verbunden. Es konnte gezeigt werden, dass reduzierte USP28 Niveaus, in Zelllinien und in vivo, niedrigere SREBP2-Aktivität und eine Herunterregulierung des Mevalonat Stoffwechselwegs ergeben. Diese Manipulation führte zu reduzierter Proliferation und Tumorwachstum. Ein direkter Vergleich von Adenokarzinomen und Plattenepithelkarzinomen in Lungenkrebspatienten zeigte zudem eine Hochregulierung von USP28 ebenso wie SREBP2 und dessen Zielgenen. Der gezielte Einsatz von Inhibitoren gegen die USP28-SREBP2 regulatorische Achse in Plattenepithelzellen reduzierte die Lebensfähigkeit und Proliferation der Zellen. Abschließend berichtet diese Forschungsarbeit von der Bedeutung des durch die USP28-SREBP2 Achse regulierten Mevalonat Stoffwechselwegs bei der Tumorinitiation und dem Fortschreiten von Plattenepithelkarzinomen. Die kombinatorische Behandlung mit USP28- und Inhibitoren der HMGCR, dem Schlüsselenzym des Mevalonat Stoffwechselwegs, mithilfe von Statinen eröffnet die Möglichkeit für eine gezielte therapeutische Behandlung von Patienten mit Plattenepithelkarzinomen.
7

Vliv výživy na poruchy metabolismu krav

Matějíček, Martin January 2014 (has links)
The aim of PhD thesis was to check effects of balanced mixed feeding rations of dairy cows at the different stages of reproduction cycle, to ensure minimal occurrence of metabolic diseases, and improve the health of animals. Selected indicators for the metabolic profile of blood plasma in 10 cows in each established group (calving preparation, early lactation and peak of lactation) were measured. In terms of protein metabolism we found in two cases significant differences in plasma total protein concentration of cows in groups calving preparation and early lactation. The concentration of bilirubin in plasma increased in the group of early cows. But there were no found significant differences. On the contrary, in the case of AST, significant differences between cows in group calving preparation and early lactation were detected. Parameters of lipids metabolism did not significantly change as well as parameters of mineral metabolism. The blood plasma calcium concentrations show a significant difference in the groups calving preparation and early lactation. The highest values of calcium achieved cows in the group of calving preparation.
8

Vliv věku a intenzity růstu na retenci vápníku v organismu kuřat

Houserová, Jana January 2009 (has links)
No description available.
9

Metabolismus sarkosinu a nádorová onemocnění prostaty =:Sarcosine metabolism and prostate cancer disease /

Strmiska, Vladislav January 2019 (has links)
Prostate carcinoma is one of the most frequent cancer diseases of maturated men. Diagnose of this cancer disease is based on level of prostatic specific antigen and digital exam per rectum. However, presence of tumor, grade and stage must be examined by biopsy. This method may not to be accurate. This is the reason why are new diagnostic methods investigated, to increase the accuracy of diagnostic prostate cancer. Amino acid sarcosine is currently on of the most widely discussed biomarker, that can serve as a diagnostic biomarker for early stage detection in prostate cancer. The present work deals with the study of sarcosine metabolism in prostate cancer cell lines, mainly, but also by amino acid metabolism in cells in general. Understanding to importance of single amino acids in malignant and non-malignant cell pathways can significantly contribute to effective targeted therapy without side effect on healthy tissue. Prostate cancer cells in presence of sarcosine increase their migration potential, malignancy by increased doubling time, and concentration of sarcosine N-demethylation enzymes, sarcosine dehydrogenase and sarcosine oxidase. Through this biochemical pathway is increased synthesis of main methylation donor S-adenosilmethyonine (SAM) ad cellular methylation potential.
10

(2,4,6-Trimethoxyphenyl)silane: Verwendung als geschützte Bausteine für die Synthese siliciumhaltiger Wirkstoffe sowie als Silylierungsreagenzien / (2,4,6-Trimethoxyphenyl)silanes: Application as Protected Building Blocks for the Synthesis of Silicon-Containing Drugs and as Silylation Agents

Popp, Friedrich January 2008 (has links) (PDF)
In Fortführung der bisher in dieser Forschungsgruppe durchgeführten Studien mit (2,4,6-Trimethoxyphenyl)silanen wurden im Rahmen der vorliegenden Arbeit weitere Untersuchungen zu den Schutzgruppen-Eigenschaften der Si-(2,4,6-Trimethoxyphenyl)-Gruppe angestellt und anschließend die hierbei gewonnenen Erkenntnisse verwendet, um Sila-Analoga bereits bekannter biologisch aktiver Verbindungen über neue Synthesewege mit (2,4,6-Trimethoxyphenyl)silanen darzustellen. Des Weiteren wurden im Rahmen der Untersuchungen zur C/Si-Bioisosterie die pharmakologischen Eigenschaften dieser bereits auf anderem Weg synthetisierten Wirkstoffe in Kooperation mit anderen Forschungsgruppen vervollständigt. Darüber hinaus wurden auch die Arbeiten zum Thema „(2,4,6-Trimethoxyphenyl)silane als Silylierungsreagenzien für O-Nucleophile“ weitergeführt. / The properties of the Si-(2,4,6-trimethoxyphenyl) group as a protecting group for silicon were further investigated as part of a continuation of the research done in this work group concerning (2,4,6-trimethoxyphenyl)silanes. The information obtained in these studies was then applied to the syntheses of silicon analogues of known carbon-based biologically active compounds by proceeding with synthetic strategies using (2,4,6-trimethoxyphenyl)silanes. Furthermore, the pharmacological properties of the synthesized compounds were investigated in cooperation with other research groups as part of studies concerning C/Si-bioisosterism. The properties of (2,4,6-trimethoxyphenyl)silanes as silylation agents for O-nucleophiles were additionally investigated as part of a related project.

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