|
|
Determination of calcium and magnesium in honey samples by atomic absorption spectrometry
Čudová, Andrea ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
This bachelor thesis is focus on the determination of calcium and magnesium in selected honey samples. Determination is performed by atomic absorption spectrometry with a flame atomization technique (F-AAS) by using an acetylene-air flame. The first part of the bachelor thesis is devoted to finding the optimal conditions of the method for further measurement of individual honey samples. These parameters are beam height above the burner edge and acetylene flow rate. Then, under these optimal conditions, the basic characteristics of calcium and magnesium determination (repeatability, sensitivity, limit of detection and limit of quatification) were found. In the second part of this bachelor thesis, the calcium and magnesium determination are performed in the honey samples. A total of 15 honey samples are analysed. The honey samples are prepared by local beekeepers from Czech Republic and retail chains (Tesco). The measured values are recorded in tables and statistically evaluated. The determined calcium concentrations range is 7.11 - 66.8 µg/g, for magnesium to 8.79 - 92.2 µg/g. Finally, the values obtained for honeys from the Czech Republic are compared with data reported in foreign studies. Key words: Atomic absorption spectrometry, flame atomization, magnesium, calcium, honey
|
|
|
The toxicity of vitamin D
Drouliskou, Eleftheria ; Mladěnka, Přemysl (advisor) ; Janoušek, Jiří (referee)
Vitamin D has essential role in skeletal health, however studies over the recent years have outlined its implication in many other physiological functions. The importance of vitamin D for health has, on one hand, raised needs for supplementation but may, on the other hand, lead to excessive administration. Vitamin D toxicity or hypervitaminosis D due to excess of vitamin D is a medical condition manifested mainly as hypercalcemia, with mostly gastrointestinal and neuropsychiatric symptoms. Long-term administration of large doses of vitamin D can result in vascular calcification and hence by associated with a cardiovascular risk. Hypervitaminosis D is extremely rare likely due to high therapeutic index of vitamin D. The clinical research shows an administration of 10.000 IU/day of vitamin D, which meets the criteria for the tolerable upper intake level, even for extended period, is probably not associated with adverse effects in almost all individuals in general population. However there are case studies globally showing vitamin D toxicity can occur due to misuse of over-the-counter vitamin D supplements, inappropriate prescribing or uncontrolled administration of high dose unlicensed preparations.
|
|
|
Gravitropism mechanisms in single-celled organs and multicellular organs of plants
Nehasilová, Martina ; Fendrych, Matyáš (advisor) ; Kurtović, Katarina (referee)
Plants react to various environmental stimuli by oriented growth. The growth responses are called tropisms. Gravitropism is a directed growth concerning the gravity vector. Plant shoots grow up, negatively gravitropically, to catch the light. Roots are positively gravitropic; they grow down to anchor the plant in the substrate and seek water and minerals. The process of gravitropism consists of three stages: signal perception, signal transmission, and growth response. These stages can all occur in a single cell or separately in different parts of a multicellular organ. Single-cell gravitropic systems are represented by algal rhizoids or moss protonemata. They need minimal signal transmission because gravity vector perception and growth response happen in the same cell. The multicellular systems, represented here by angiosperm roots, have a more robust signal transmission phase. This thesis compares mechanisms of plant gravitropism based on the two categories - single-cell vs. multicellular. Despite their different cellular arrangements, single-cell and multicellular gravitropism share several characteristics, such as statolith sedimentation, Ca2+ fluxes, pH changes, and altered vesicular trafficking. Still, the lack of knowledge about the single-cell systems and high inner variability within the...
|
|
|
Neurosteroid effects on intracellular calcium and excitotoxicity
Naimová, Žaneta ; Smejkalová, Terézia (advisor) ; Adámek, Pavel (referee)
NMDA receptors belong to the family of ionotropic glutamate receptors, and are involved in synaptic plasticity, learning and memory. However, overactivation by the agonist glutamate can lead to neuronal death - excitotoxicity. Exitotoxicity is a result of excessive calcium influx into the cell through NMDA receptors, and is associated with many cental nervous system (CNS) diseases. Neurosteroids are endogenous compounds capable of NMDA receptor modulation, thus they may have pharmacological potential in the treatment of CNS disorders. The aim of this work was to investigate how pregnanolone sulfate (PA-S) and pregnanolone hemipimelate (PA-hPim) influence somatic calcium and excitotoxicity. We used fluorescence microscopy for recording changes in somatic calcium concentration. We observed that PA-S had no influence on relative somatic calcium concentration. Synthetic analog PA-hPim increased somatic calcium levels slightly. Next, we used oxygen-glucose deprivation (OGD) in vitro to study the influence of neurosteroids on excitotoxicity. Both PA-S and PA-hPim were neuroprotective in the model of acute OGD in vitro. Moreover, PA-S or PA-hPim pretreatment induced ischemic tolerance to a subsequent OGD episode. Our results suggest that neurosteroids PA-S and PA-hPim are potential candidates for the development...
|
|
|
Adherence to calcium and vitamin D supplementation in women with postmenopausal osteoporosis
Holcová, Radka ; Vytřísalová, Magda (advisor) ; Fuksa, Leoš (referee)
Adherence to calcium and vitamin D supplementation in women with postmenopausal osteoporosis Author: Radka Holcová Supervisor: Magda Vytřísalová Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Social and Clinical Pharmacy Introduction: The insufficient medication adherence is a very frequent problem with chronic asymptomatic diseases as osteoporosis which significantly influences the treatment outcome. The successful osteoporosis therapy is based on adequate supply of calcium and vitamin D. A lot of studies are focused on the adherence to antiresorptive treatment but the adherence to supplementation therapy is rarely evaluated. Aims: The aim of the study was to evaluate the adherence to calcium and vitamin D supplementation in women with postmenopausal osteoporosis. Methods: The adherence was evaluated using two different methods: self-reported questionnaire and the electronic monitoring by bottles type Medication Event Monitoring System (MEMS). This partial analysis of a multicentre study includes and assesses data from Osteocentre in Pardubice Regional Hospital. Results: The analysis was performed with 15 women (the average age of 73). The patients were treated with Caltrate 600 mg/400 IU D3 once a day for three months. The adherence during the entire period...
|
|
|
Application of Atomic Absorption Spectrometry for Determination of Selected Elements from Potential Ecological Burden Area
Juránková, Lada ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
This work is focused on the determination of selected (chemical) elements (Fe, Mn, Zn, Cr, Na, K, Mg a Ca) in a potential ecological burden area using flame atomic absorption spectrometry as a detection technique. A potential ecological burden is represented by tires which are used as a construction material or as an environment surrounding for growing decorative and consumable plants. Analytes were determined in plant origin samples. Firstly, the samples were dried in a laboratory electric dryer. The weighted amount of a dried sample (approximately 0.2 g) was digested inside a microwave decomposition device with an addition of nitric acid and hydrogen peroxide. An optimization of experimental parameters was done for each of the elements before sample measuring. A burner height was optimized and 8 mm height was chosen as a optimum for most elements. Under the optimum condition basic characteristics were measured for each element separately. These characteristics included limits of detection that were: 0.05; 0.01; 0.08; 0.21; 0.02; 0.01; 0.01; 0.01 mg L-1 for the following elements: Fe, Mn, Zn, Cr, K, Ca, Mg and Na, respectively. The limits of quantification, sensitivity and repeatability were determined for each element as well. A significant attention was paid to the content of zinc in the studied...
|
|
|
The effect of acute cold and permanent light to left ventricular of the rat heart
Vítková, Ivana ; Žurmanová, Jitka (advisor) ; Bendová, Zdeňka (referee)
Acute cold exposure increases the risk of sudden cardiac events, similarly exposure to constant light negatively affects the cardiovascular system. However, the individual effects of these factors and the effect of their combination on cardiomyocytes are not yet known. The thesis deals with the influence of a 3 day cold exposure and constant light on the expression of β-adrenergic receptors and associated G-proteins in association with apoptotic signals in the left ventricle of the Wistar rat heart. In this work apoptotic proteins BAX, BCL2, caspase 8 and important components of β-adrenergic signalization - β1, β2, G-proteins, Gas, Gi1/2 and Gi3 were determined. The relative expression of the proteins was analyzed by Western blotting. The results confirm the detrimental effect of cold and light exposure. However, the synergistic effect of these two stressors shows surprising results.
|
|
|
Risk factors of osteoporosis and fractures in people over 65 years of age
Malimánková, Jana ; Zikán, Vít (advisor) ; Šimková, Simona (referee)
This diploma thesis deals with risk factors of osteoporosis and fractures among people older than 65 years. Theoretical part contains the definition of osteoporosis, physiology of bones, hormonal regulation, determinants of disease, clinical manifestation, prevention of disease and old age. Essential chapters of theoretical part are about moving activity and nutrition. Aim of this thesis was to evaluate the occurrence of osteoporosis and risk factors of fractures in connection with risk nutritional factors. The research includes 86 responders, who filled out the questionnaire of risk factors and the risk of fractures was found out using FRAX tool. Based on these results patients were divided into 2 groups: with high risk and low risk of fractures. 10 patients of each group provided 3-day menu. The densitometric examination was accomplished to 30 responders and the probability of fracture formation was evaluated. The results of diploma thesis show, that 45 % of responders have higher risk of fracture formation. This group has significantly higher age and lower BMI. This research then showed that patients with higher risk of fracture formation get significantly less energy, proteins, fats, carbohydrates, and calcium. Moreover, most of participants has insufficient intake of dairy products and fish....
|
|
|
The role of nutrition in the prevention of osteoporosis: calcium, proteins and gut microbiota
Holánová, Karolína ; Zikán, Vít (advisor) ; Vágnerová, Tereza (referee)
Introduction: Osteoporosis is defined as a systemic metabolic disease of skeleton. It is characterized by reduced amounts of bone mass and degradation of bone tissue microarchitecture with increased chances of fractures occurring. Women after menopause are affected by lack of estrogen and therefore have increased risk of osteoporosis. Goal: The goal of the diploma thesis is to evaluate the nutritional state of women after menopause with osteoporosis (With OP) and without osteoporosis (Without OP) focusing on calcium, proteins and nutrients which are affecting gut microbiota (prebiotics and probiotics). Methods: Nutritional state was evaluated based on three-day diet analysis and questionnaire about dietary preferences. Amounts of particular nutrients in respondents diets were obtained by using web page www.kaloricketabulky.cz. Bone material densities were measured by dual energy X-ray absorptiometry (DXA). Results: Nutritional breakdown of diets did not show any statistically significant differences in most of the cases. The only exception was protein and fiber intake, where the group without OP reported higher intake. Both sets of respondents reported higher intake of calories, fats and proteins then recommended. On the other hand, low intake of carbs, fiber, calcium and probiotics was discovered...
|
|
| |
guest ::
