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Fuels in 21. century
Lébl, Jan ; Svída, David (referee) ; Dundálek, Radim (advisor)
This bachelor’s thesis is intent on introducing the overview of particular types of fuels used at present for ignition and diesel internal combustion engines. Marginally is mentioned the theme of fuels used for fuel cells. Further it deals with the composition of each fuel types and their characteristics and ecological aspects of their use. The ending of the thesis is aimed to formulation of the development trends in fuels and the prospects of each fuel type’s expansion in the future.
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Coincidental finding of hyperglycemia in children and adolescents
Feigerlová, Eva ; Lebl, Jan (advisor) ; Houšťková, Hana (referee) ; Haluzík, Martin (referee) ; Stárka, Luboslav (referee)
Donedávna se v souvislosti s diabetem v pediatrické populaci uvažovalo téměř výhradně O diabetu mellitu I. typu (Tl DM) s jeho typickou klinickou symptomatologií zahrnující polyurii, polydipsii, váhový úbytek a případně projevy ketoacidÓzy. Nyní na diabetes mellitus dětského věku a adolescence pohlížíme jako na heterogenní onemocnění zahrnující skupinu poruch s rozdílnou patogenezí, průběhem a odpovědí na léčbu (ADA 2005). V některých případech je klinická symptomatologie velmi sporá a může se omezit jen na náhodné zjištění mírné hyperglykémie v rámci vyšetřování pro různé klinické stavy. Náhodnou hyperglykémií se rozumí zvýšená glykémie nad referenční mez u jinak zdravého, klinicky asymptomatického jedince, stanovená z náhodného žilního odběru nalačno za bazálních podmínek (např. v rámci preventivní prohlídky) či během zátěžové situace (např. v průběhu akutně probíhající onemocnění, v souvislosti s chirurgickým zákrokem či úrazem). Dle definice (ADA 2005, WHO 1999) se za fyziologické považují hodnoty plazmatické glykémie nalačno nižší než 5,6 mmol/I za předpokladu dodržení podmínek preanalytické přípravy. Normální hodnota glykémie měřená 2 hodiny po standartní zátěži v průběhu OGTI (orálního glukózového tolerančního testu) je nižší než 7,8 mmolll. I přes existenci jasných kritérií nepovažuj í některé...
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Pathophysiological mechanisms and optimization of diagnosing congenital adrenal hyperplasia
Malíková, Jana ; Lebl, Jan (advisor) ; Vrbíková, Jana (referee) ; Zapletalová, Jiřina (referee)
Autoreferát 5 Summary Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive diseases which are characterized by inadequate secretion of steroid hormones of the adrenal cortex. The most common type of CAH is a deficiency of 21-hydroxylase (CYP21A2 gene), which leads to insufficient secretion of mineralocorticoids and glucocorticoids and excessive androgen production. There is apparent good correlation between the type of mutation and a 21-hydroxylase deficiency, and subsequently the clinical presentation. Neonatal screening for CAH was introduced to early and effectively recognize the most severe type of 21-hydroxylase deficiency (salt wasting form of CAH). Neonatal screening CAH is based on the detection 17-OHP level in dried blood spots by fluoroimmunoassay (Delfia). In the Czech Republic NS CAH was implemented to screening program in 2006. During the period of 2006 - 2011 we evaluated the results of NS CAH and we observed sensitivity of 98%, specificity of 99.5%, a low positive predictive value (PPV) of 1.6% and a high false positive rate (FPR) of 0.51% in the whole group examined newborns. Due to the low positive predictive value in the part of neonatal population (0.51%) the levels of 17-OHP are repeatedly checked for transiently elevated levels of 17-OHP above the cut-off limit of...
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Pendrin in the pathogenesisof congenital hypothyroidism
Banghová, Karolína ; Lebl, Jan (advisor) ; Límanová, Zdeňka (referee) ; Houšťková, Hana (referee) ; Stárka, Luboslav (referee)
Pendrin is an anion transporter that is expressed in several organs. In the thyroid gland, pendrin is localized at the apical pole of thyrocytes and it is responsible for the iodide efflux from thyrocytes into the colloid in the follicular lumen where iodide is organificated. The extrathyroidal expression was shown in the inner ear, kidney, placenta and mammary gland. Carriers of mutations in the pendrin gene (PDS, SLC26A4) display variable phenotypical features following the autosomal recessive manner of the inheritance: combined thyroid and hearing affection (Pendred syndrome - OMIM274600), nonsyndromic autosomal recessive neurosensory deafness (DFNB4 - OMIM600791) or isolated enlarged vestibular aqueduct (EVA - OMIM603545). The thyroid affection is usually manifested as euthyroid or hypothyroid goitre in the second decade of life. In a minority of patients, dyshormonogenesis is present at birth, and the disease is diagnosed in the frame of the nation-wide neonatal screening for congenital hypothyroidism.
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Clinical and genetic characteristic of selected types of monogenic diabetes mellitus
Gonsorčíková, Lucie ; Lebl, Jan (advisor) ; Pelikánová, Terezie (referee) ; Kohoutová, Milada (referee)
1. English Summary The aim of this thesis was to find out the etiology of diabetes mellitus in patients with a family predisposition to the disease. The world-wide increase in the incidence of diabetes in the past years has lead to intensive research of its etiological and pathophysiological mechanisms. This research has helped to discover many genes whose mutations were proved to cause diabetes without a contribution of other factors. Such cases where a mutation in a single gene crucial for glucose control is sufficient to result in diabetes are referred to as monogenic diabetes. This group includes a broad spectrum of hyperglycaemic conditions that differ significantly in their prevalence, course, treatment as well as prognosis. The so called MODY (maturity onset diabetes of the young) belongs to this group and is characterized by early onset before 25 years of age and no need of insulin substitution initially. In this study we were looking for mutations in genes that may be a rare cause of monogenic diabetes. We examined patients with hyperglycaemia occurring in several generations of their families and in whom mutations in more prevalent MODY genes had been previously excluded. We performed a genetic analysis of genes NEUROD1, IPF-1 and ABCC8. The protein NEUROD1 is a crucial transcription factor that...
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Retrospective diagnosis of unknown cause of sudden infant death
Strnadová, Kristina ; Lebl, Jan (advisor) ; Janda, Jan (referee) ; Plavka, Richard (referee) ; Vízek, Martin (referee)
Background: Sudden infant death syndrome (SIDS) is defined as sudden unexpected death of an infant that remains unexplained after thorough post-mortem examination, investigation of the scene of death and case history. The autopsy findings and the physiological characteristics of these infants suggest a possible role of insufficient cardiorespiratory control and arousal mechanisms. The etiology is probably multifactorial based on a genetic predisposition combined with environmental factors. Several candidate genes have been studied, e.g. those involved in serotonin transport, autonomic nervous system embryology, inflammation, energy production, nicotine and glucose metabolism. A small number of cases may be caused by monogenic diseases that can lead to sudden death and leave no characteristic autopsy findings and thus imitate SIDS. Fatty acid beta-oxidation disorders (FAOD) have been associated with SIDS since 1976 and it is nowadays estimated that they may be responsible for about 1% of SIDS cases. Congenital long QT syndrome, a cardiac channelopathy, that may cause a fatal arrhythmia was a logical candidate for SIDS and indeed it was found out that about 9,5% of SIDS cases carry a mutation or a function changing variant in one of seven cardiac ion channel genes. We assumed that the severe salt...
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Genetic and Hormonal Regulation of Children's Growth
Vosáhlo, Jan ; Lebl, Jan (advisor) ; Marek, Josef (referee) ; Vaňková, Markéta (referee)
Genetic and Hormonal Regulation of Children's Growth MUDr. Jan Vosáhlo Abstract Growth in childhood is a complex process of changing the body, which can be disrupted by various illnesses including endocrine disorders, particularly growth hormone deficiency. Tumors or other processes affecting hypothalamic-pituitary area can be a postnatal cause of GHD; prenatal causes include 1) developmental disorders of the pituitary as part of complex syndromes, 2) developmental disorders of the pituitary due to defects in regulatory genes and 3) defects in genes involved in the synthesis and secretion of GH. The first topic of the thesis was septo-optic dysplasia - a complex syndrome involving optic nerve hypoplasia, structural brain abnormalities and pituitary dysfunctions. We extensively described phenotype in 11 Czech patients; we observed both complete SOD and incomplete forms variously combining two of the three main components of the syndrome. The cohort then became a part of an international study of 68 patients, in which we studied the phenotype in dependence on the brain morphology. We found correlation between the severity of clinical symptoms and the degree of septum pellucidum abnormities and also a correlation between hippocampus and falx abnormities and neurological symptoms. As the second topic we studied...
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Stress-strain Analysis of Tractor Exhaust Tail-pipe
Lébl, Jan ; Píštěk, Václav (referee) ; Dundálek, Radim (advisor)
This diploma thesis deals with the strength and frequency analysis of tractor exhaust pipe, which is being developed as an economic alternative in the preparation of construction for use in convertible tractor’s in the Zetor Tractors company. First, modal analysis is performed to determine the natural frequency of the exhaust pipe. In the next section it deals with stress-strain analysis to assess the overall structural strength of the exhaust pipe. At the end is performed thermodynamic analysis to assess the thermal resistance. For these calculations was used the finite element method (FEM) using computing software ANSYS 13.
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