National Repository of Grey Literature 187 records found  beginprevious153 - 162nextend  jump to record: Search took 0.00 seconds. 
New findings of physiological and ecological aspects of hibernating bats
Ungrová, Zdislava ; Jahelková, Helena (advisor) ; Lučan, Radek (referee)
Bats can be found in almost all climatic zones. They have to deal with unfavorable conditions of environment to survive and reproduce sucessfully. Especially in temperate zones they have to deal with cold temperatures and lack of food during a winter season. To save energy bats enter a short, diurnal torpor or a hibernation. Usually, hibernation lasts all winter and is disturbed by short bouts of arousals. During both hibernation and torpor a physiological changes occur in bodies of bats. Body temperature decreases from endothermic levels, metabolic rates are reduced as well as respiratory rate and pulse. These changes are mainly influenced by weight and body size, diet, ambient temperature, sex and reproductive status. With the developement of new technologies, these changes can be measured more accurately than they have been in past, whether in a field or in a laboratory. But not all physiological processes are well explained. We have little knowledge especially about mechanism of arousal from hibernation. During awakening bats are infected by fungus Geomyces destructans that affects their immune system. In Norh America fungus causes a disease called White- Nose syndrome (WNS), that is responsible for death of millions of bats, especially endangered is Myotis lucifugus. In Europe, this disease is reffered...
Metabolism of uric acid during mammalian evolution
Mančíková, Andrea ; Krylov, Vladimír (advisor) ; Stibůrková, Blanka (referee)
Uric acid is the end product of purine metabolism of humans and some higher primates. In other mammals enzyme urate oxidase is capable to further convert uric acid to allantoin. During evolution of primates several mutations in urate oxidase gene had occured, led the enzyme to decrease its activity or to complete loss of function. What was the initial impetus for the utilization of uric acid and what biochemical traits of uric acid led to a tendency to retain a major of this metabolite production in the bloodstream? Uric acid has antioxidant capabilities and it is scavanger of free radicals. Increased levels of uric acid in blood has an effect on acute and chronic elevations of blood pressure. It is possible that hyperuricemia helped to maintain blood pressure under low-salt dietary conditions of primates during the Miocene. This mechanism probably have allowed to stabilize bipedalism our ancestors. Uric acid has an important role as a neuroprotector. As inhibitor the permeability blood-brain barrier, uric acid limits the infiltration of undesirable substances to the neurons and prevents central nervous system against the formation of inflammatory diseases. Such as neurodegenerative diseases may be caused by reduced serum uric acid levels. Uric acid protects against peroxinitrite damage tissues in the...
Effects of chemopreventive compounds on cytochrome P450s
Křížková, Jitka ; Hodek, Petr (advisor) ; Helia, Otto (referee) ; Václavíková, Radka (referee)
CHARLES UNIVERSITY IN PRAGUE Faculty of Science Department of Biochemistry Effects of chemopreventive compounds on cytochrome P450s Summary of Ph.D. Thesis RNDr. Jitka Křížková Supervisor: prof. RNDr. Petr Hodek, CSc. Prague 2010 Introduction 1 Introduction According to the World Health Organization statistics, cancer is one of the leading causes of death in the human population worldwide for more than 50 years. Moreover, colorectal and gastrointestinal tract cancers are one of the main types of cancer leading to overall cancer mortality. Prevention consisting in a healthy lifestyle and a natural diet is suggested to be one of the main approaches to reduce cancer risk. In recent years, the consumption and use of dietary supplements containing concentrated chemopreventive phytochemicals increased dramatically. Flavonoids, as the most popular representatives of chemopreventive compounds, present in foods (fruits, vegetables, herbs, beverages) and dietary supplements have the potential to modulate the activity of xenobiotic-metabolizing enzymes [Hodek et al., 2002]. Among proteins interacting with flavonoids, cytochrome P450s (CYPs), monooxygenases metabolizing xenobiotics (e.g. drugs, carcinogens), play the most prominent role. The two members of CYP1A subfamily, CYP1A1 and CYP1A2, are involved in the...
Applications of chiral and achiral chromatography in pharmacology and toxicology
Chytil, Lukáš ; Slanař, Ondřej (advisor) ; Bultas, Jan (referee) ; Coufal, Pavel (referee)
Development and validation of methods for analysis of several drugs or their metabolites are decribed in this thesis. The document is presented as a commentary to the original papers, which were published in peer reviewed journals. Discussion on the optimization of each method is presented and covers also method development and influence of preanalytical aspects. Additionally, examples of the application of the developed methods in clinical pharmacology and toxicology are shown. This dissertation consists of three parts: enantiomeric determination of tramadol and its metabolite, determination of some antihypertensive drugs, and qualitative analysis of benzodiazepines. Development of a method for chiral analysis of tramadol and its desmethylated metabolite O- desmethyltramadol (ODT) in human urine and plasma is described in the first part of the thesis. Tramadol is a centrally acting analgetic drug, which is used as racemate in clinical practise. Each enantiomer displays different binding properties for various receptors: (+)-tramadol preferentially inhibits serotonin reuptake while (-)-tramadol mainly inhibits noradrenalin reuptake. (+)-tramadol is considered 10-times more potent than (-)-tramadol. Major active metabolite (ODT), which is considered to be the main agent responsible for the...
Phytoremediation:biochemical characteristics of heavy metal hyperacumulators
Lábusová, Jana ; Lipavská, Helena (advisor) ; Podlipná, Radka (referee)
Water and soil pollution by heavy metals is a very serious problem of nowadays. Since the beginning of industrial revolution, the concentration of heavy metals increased sharply in the environment. One way how to decontaminate soils and groundwaters is phytoremediation that uses plants to remediate pollutants from the contaminated sites. This eco-friendly and cost- effective method exploits the ability of plants to take up, translocate, transform and sequester metals. In phytoremediation, the plants that are able to accumulate metals to high concentration are mainly used. These plants are named "hyperaccumulators". Accumulation of metals by plants is affected not only by the capability of plant in question, but to a great extend also by the form and concentration of metal in the soil and environmental conditions. The aim of this Bachelor thesis is to summarize knowledge on impact of heavy metals on biochemical changes in plants, with special emphasis on changes in carbohydrate metabolism.
The Interplay Between the Notch Signaling Pathway and Cellular Metabolism
SLANINOVÁ, Věra
We identified four metabolic genes as direct targets of Notch signaling pathway both in vitro and in vivo and investigated the hypothesis that Notch directed metabolic changes support the growth of the imaginal wing dics. Vice versa, we observed the influence of metabolic changes on the activity of Notch signaling pathway and we identified Sirt1 as a metabolic sensor for the Notch pathway that helps to elicit an efficient response to Notch signal, in a metabolism sensitive manner.
Analýza metabolických a reprodukčních ukazatelů ovcí ve vybraném chovu plemene suffolk
OUŘEDNÍKOVÁ, Kateřina
The aim of the study was to analyze the reproductive, productive and metabolic values of ewes from selected parameters in blood, milk and urine in correlation to their metabolic state. The results were used to draw up new breeding and feeding schemes. The research was carried out in 2015, and the sample size consisted of 62 Suffolk ewes. The analysis of reproductive parameters of selected ewes confirms appropriately chosen breeding methods. The average weight of lambs at birth (3,82 kg) is affected by the number of lambs at birth. The average weight of lambs at 100 days of age (32,54 kg) depends on the number of lambs per ewe and the age of ewe. The average daily weight gain makes 0,325 kg per lamb. Lowered concentration of proteins related to the decreased level of urea in the blood plasma signifies insufficient intake of nitrogen of ewes from feed.
PowerCube spirometry measurement
Krajčovič, Martin ; Závodná, Eva (referee) ; Provazník, Ivo (advisor)
This paper is dedicated to the issue of respiratory physiology, human body energy exchange and calorimetry. It describes functions of the PowerCube-Ergo-Device (Ganshorn Medizin Electronic, Germany), which serves ergospirometry measurement and designes a protocol used to measure and evaluate the cardiopulmonary response of the organism and the metabolic activity of the organism in a group of athletes and non-sportspeople. Furthermore, it constitutes an application developed in MATLAB programming environment, allowing graphical portrayal and evaluation of measured data. The final part of this thesis is devoted to statistical evaluation of the data gathered within the selected group of patients.
Milk composition as an indicator of the metabolism of dairy cows
ŠTĚRBA, Lukáš
Milk presents good marker metabolic levels in dairy cows. Subscribe milk in moreover to cow does not stressful. Each month has a breeder in the yield control available basic data on milk composition (fat, protein, lactose). This basic data can be expanded to include other parameters (milk urea, ketones and citric acid). Based on these milk parameters can then correct interpretation preventively diagnose metabolic diseases in the herd. In this work, based on yield controlling diagnosed with high metabolic burden herd Haklovy Dvory. In March 2014, according to the results of the composition of milk probably 33,3% of dairy cows exposed to challenges from acidogenic burdens and 15,2% negative energy balance. In April, was then exposed to challenges from acidogenic burdens 37,8% of herds and negative energy balance 26,7% of the herd. For selected cows are then carried out an analysis of the metabolic state based on milk composition and biochemical blood tests. Milk always signaled higher metabolic burden cows associated with the appearance of serious metabolic diseases (acidogenic burdens) than blood. Diagnosis of rumen acidosis of the blood is not simple and milk, this could serve as a useful indicator of the current state of the acid-base balance in the rumen.
The thyroid gland activity of sheep
DŘÍZHALOVÁ, Blanka
In the theoretical part of my thesis, I describe the thyroid, its importance, anatomy, creation of hormones and their regulation. There is also summarized the knowledge of external environment influences on the thyroid such as nutrition, climatic conditions or seasons and internal factors influences, mainly breed, efficiency and age. The practical part is focused on the evaluation of the thyroid activity of free-range ewes and lambs in the spring and autumn of 2013. The thesis also deals with the evaluation of possible relevance between the content of thyroid hormones in the blood serum and the physiological state of the sheep. Thanks to the correlation between TSH and thyroid hormones, the proper regulation of the thyroid of ewes and lambs was confirmed. The thyroid activity was higher in the spring than in the autumn. The hypothyroidism in the autumn was not proved because no referential values of TSH are set. In the autumn there was a lower level of glucose and cholesterol in the blood of the ewes determined which gives evidence of a lower energy income from the feed in the autumn. Also the urea level which is closely connected to the energy shortage, starvation, and high income of N substances in the feed dosage was in the autumn twice as high as in the spring. There was a positive correlation determined between the higher urea concentration and the higher thyroid activity. Owing to the change of the feed content, the TSH started to stimulate the thyroid to a higher thyroid hormones production and thus to its higher activity.

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