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Preparation of a method for detection of the extent of chelation of calcium and magnesium ions
Konečný, Lukáš ; Mladěnka, Přemysl (advisor) ; Jáč, Pavel (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Lukáš Konečný Supervisor: prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of Thesis: Preparation of a method for detection of the extent of chelation of calcium and magnesium ions Calcium and magnesium are biogenic elements belonging to the second group of the periodic table. Calcium is the fifth most abundant element in the human body. In addition to its important role in bone homeostasis, calcium is involved in other processes such as blood clotting, muscle contraction and regulation of nerve excitability Magnesium is the cofactor of many enzymatic reactions essential for a row of physiological functions. The aim of this work was to propose a novel screening method for determination of the degree of calcium and magnesium chelation. In the first step the UV-vis spectra of the selected indicator o-cresolphthalein complexone and its complexes with calcium and magnesium were measured. This was followed by verification of the linearity and the determination of the sensitivity of the method. Concurrently the stability of the indicator and its complexes with both ions was measured. In the last step, the suitability of the method was verified on a standard chelator ethylenediaminetetraacetic acid...
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Molecular mechanisms of polymodal regulation of TRPA1 receptor
Sinica, Viktor ; Vlachová, Viktorie (advisor) ; Vondrášek, Jiří (referee) ; Holendová, Blanka (referee)
The TRPA1 channel is a universal, nociception-mediating cellular sensor activated by various environmental irritants, potentially harmful physical modalities and endogenous mediators of pathophysiological processes. The polymodality of TRPA1 channel allows the activation stimuli to further enhance or suppress each other's effect. While this modulation effect has its physiological importance in promoting the protective cellular and behavioral mechanisms, it may result into the unpleasant pain-related effects accompanying the chronical pain caused by aberrant TRPA1 channel activity. In order to effectively and selectively target the synergic properties of TRPA1 modulators, while preserving the sensitivity to the environmental threads, the knowledge of the mechanisms of polymodal regulation at the molecular level are required. This doctoral thesis aims at the elucidation of three main mechanisms of TRPA1 regulation: 1) the regulation via intracellular signaling cascades and phosphorylation, 2) the interaction with membrane phospholipids and 3) the temperature-driven gating. The results presented in the thesis show that the effects of the inflammatory mediator bradykinin are decreased by the low-frequency high-induction electromagnetic field used in magnetotherapy. We have identified a residue S602...
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Simulation of processes in cellular membranes
Melcr, Josef ; Jungwirth, Pavel (advisor)
Simulation of processes in cellular membranes Abstract Many important processes in cells involve ions, e.g., fusion of synaptic vesi- cles with neuronal cell membranes is controlled by a divalent cation Ca2+ ; and the exchange of Na+ and K+ drives the the fast electrical signal transmis- sion in neurons. We have investigated model phospholipid membranes and their interactions with these biologically relevant ions. Using state-of-the-art molecular dynamics simulations, we accurately quantified their respective affinites towards neutral and negatively charged phospholipid bilayers. In order to achieve that, we developed a new model of phospholipids termed ECC-lipids, which accounts for the electronic polarization via the electronic continuum correction implemented as charge rescaling. Our simulations with this new force field reach for the first time a quantitative agreement with the experimental lipid electrometer concept for POPC as well as for POPS with all the studied cations. We have also examined the effects of transmembrane voltage on phospholipid bilayers. The electric field induced by the voltage exists exclusively in the hydrophobic region of the membrane, where it has an almost constant strength. This field affects the structure of nearby water molecules highlighting its importance in electroporation. 1
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Effect of fatty acids on lipid metabolism and weight reduction
Hlavatý, Petr ; Kunešová, Marie (advisor) ; Müllerová, Dana (referee) ; Flachs, Pavel (referee)
Fat tissue plays a main role in the development of the metabolic syndrome. Many components of the metabolic syndrome may be improved by dietary arrangements, including an increased intake of n-3 PUFA. In addition to the positive effect of n-3 PUFA, a possible effect of a higher calcium intake on influencing weight loss and energy metabolism has also been discussed for a long time. In addition to nutritional factors, genetic factors significantly contribute to influencing weight and lipid and glucose metabolism. In study A, 40 obese women were observed during three weeks of weight reduction management. Women were randomly divided into two groups. The first group received yogurt enriched with n-3 PUFA, and the second group consumed yoghurt without the supplementation. The results show that low-dose supplementation with n-3 PUFA in yogurt in combination with a reduced energy intake increases n-3 PUFA content in serum lipids and prevents adverse changes in the composition of FA in serum after a short-term low-calorie diet. In study B, we monitored the influence of n-3 PUFA supplementation on short-term weight management with VLCD in 20 women with severe obesity, who were randomly divided into two groups. The first group received VLCD enriched with n-3 PUFA, the second group VLCD with a placebo. The addition of...
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Calcium homeostasis and modulation of nociceptive synaptic transmission
Sojka, David
This study was designed to improve our knowledge regarding mechanisms of nociceptive signaling at spinal cord level. One of the forms of spinal cord synaptic transmission modulation is central sensitization, a manifestation of synaptic plasticity at spinal cord level, which was found to be present at many chronic pain syndromes. This study deals mainly with a development of calcium imaging technique with a final goal to study mechanisms of central sensitization in vitro on population of dorsal horn neurons. We have analyzed synaptically evoked intracellular Ca changes as a result of dorsal root stimulation in a superficial dorsal horn area in spinal cord slices and found two types of Ca responses: one synchronized with electrical stimulation and a second one, delayed response due to Ca release from internal stores. The delayed Ca release was not previously shown to be present in these neurons and it was not dependent on activation of ionotropic glutamatergic receptors, suggesting involvement of metabotropic receptor pathway. The presence of this delayed type of Ca response could have a significant role in the induction of some types of chronic pain syndromes, since intracellular calcium increase is thought to be a key trigger point in spinal cord neurons sensitization. An important role in neuronal calcium...
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Studies on molecular interactions of the mu-opioid and TRPV1 receptors
Melkes, Barbora ; Novotný, Jiří (advisor) ; Blahoš, Jaroslav (referee) ; Krůšek, Jan (referee)
In this work, we investigated the behavior of the -opioid receptor (MOR) and the transient receptor potential vanilloid 1 (TRPV1) ion channel in the plasma membrane and their mutual communication. Both these receptors are implicated in pain perception and analgesia. We observed that the lateral mobility of MOR was strongly affected by different biased opioid agonists. DAMGO and endomorphin-2 display opposite bias towards MOR. According to our results, they also have the opposite effects on the mobility of MOR. Morphine induced only small changes in the mobility of MOR. Moreover, cholesterol depletion and blockage of G protein signaling by pertussis toxin (PTX) affected the ability of different MOR agonists to alter MOR mobility in a unique manner. The effects of DAMGO and endomorphin-2 were compromised under these conditions. On the other hand, we observed increased movement of MOR after the addition of morphine. PTX alone did not affect receptor movement, but it completely disrupted the effect of cholesterol depletion on morphine induced changes the mobility of MOR. Next we studied the mobility of TRPV1. The TRPV1 agonist capsaicin changed the lateral mobility of TRPV1. Surprisingly, after adding the MOR antagonist naloxone, the apparent diffusion coefficient of TRPV1 but to a lower extent than...
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Milk and dairy products and their perception by young adults
Valchová, Jana ; Křížová, Jarmila (advisor) ; Hásková, Aneta (referee)
Early adulthood is a period of peak bone mass formation, which is one of the basics in prevention of osteoporosis onset in older age. Milk and dairy products intake as a source of well-absorbed calcium is still very substantial at this age, as it was in the previous period of adolescence. However, it is also often a time of finding a person's own diet and a time of eliminating certain food groups from the diet, which is often due to succumbuing to widespread myths. Thus, milk is one of the most controversial foods for the public. The aim of the questionnaire research, which was part of the thesis, was to find out, how many young adults believe and succumb to these myths. Questions were asked about eating habits and respondents' views on the health benefits of milk. The survey shows that a significant percentage of them are misinformed by such myths and exclude milk from their diet, often for no reason. Although campaigns to promote milk consumption are still ongoing and have undoubtedly had a positive effect on public perception of the benefits of milk, it is certain that this activity needs to be continued and myths (not only) about milk still need to be debunked. keywords: milk, dairy products, early adulthood, myths, peak bone mass, calcium
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Determination of selected elements in potato tubers by atomic absorption spectrometry
Fořtová, Lucie ; Hraníček, Jakub (advisor) ; Kozlík, Petr (referee)
The main aim of this bachelor thesis was a determination of the elements K, Mg, Ca, Na, Zn and Fe in the potato tubers and in their boiled solution using the method of flame atomic absorption spectrometry. The chosen samples were late consumer potato tubers of Granada cultivar (boiling type B). It was necessary to optimize working conditions before the sample analysis. The optimal flow rate of acetylene ranged from 2.0 to 2.5 l/min using the flame acetylene-air. The flame acetylene-nitrous oxide was used only for calcium with flow rate 6.0 l/min. The optimal height of a beam above the burner edge was measured in interval 5 to 7 pieces of defined scale mentioned in a manual for spectrometer GBC 933 AA. Using the optimal conditions, the basic characteristics for individual methods of determination were characterized (LOD, LOQ, LDR, sensitivity, repeatability). Limits of quantification were following: 78, 31, 7.0, 8.0, 190 and 71 μg/l for K, Na, Mg, Ca, Fe and Zn, respectively. The optimal conditions were used for the determination of the selected elements in samples. The solutions were prepared from diversely processed potato tubers (whole, whole without skin, chopped without skin, skin) by boiling into deionized water. After the samples had cooled down, the concentrated nitric acid was added...
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Risk of osteoporosis in postmenopausal women after successful surgical intervention for primary hyperparathyroidism: nutritional factors
Vokounová, Kateřina ; Zikán, Vít (advisor) ; Michalská, Dana (referee)
Introduction: Osteoporosis is a chronical systemic metabolic disease of bone tissue, which is manifested by a decrease in the amount of bone mass and/or a decrease in its quality and may result in a fracture. Fractures are also common for primary hyperparathyroidism due to increased parathyroid hormone secretion. Surgical treatment will help increase bone density in most cases, nevertheless emphasis is placed on reducing risk factors for osteoporosis and fractures. Objective: Purpose of this thesis is to map the nutrition condition with focus on calcium and protein intake of postmenopausal women after successful surgical intervention for primary hyperparathyroidism (PHPT group), and to evaluate the results in relation with osteoporosis and fractures. Methods: Nutritional status was assessed using questionnaires of eating habits and analysis of three-day menus. Intakes of energy, protein, fat, sugar, fiber, free sugar, vitamin C, sodium, calcium nad phosphorus intake were calculated using Nutriservis PROFI program (and other nutritional databases). The degree of vitamin D saturation was obtained from serum calcidiol concentrations. Body composition and bone mineral density parametres were measured using dual energy X-ray absorptiometry. Results: Nutritional analysis of diets showed no statically...
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