Salivary cortisol responses to psychosocial stress are associated with birth weight and length of gestation.

Fetal programming of the hypothalamus-pituitary-adrenal (HPA) axis was proposed as one mechanism underlying the link between prenatal stress, adverse birth outcomes (particularly low birth weight) and an enhanced vulnerability for several diseases later in life. In recent studies, birth weight was significantly related to basal cortisol levels as well as to cortisol responses to pharmacological stimulation.In order to investigate the association between cortisol responses to psychological challenge, birth weight and length of gestation, 106 young healthy males were exposed to the ‘Trier Social Stress Test’. Salivary cortisol responses to the stress exposure were significantly and inversely related to the subjects' birth weight, while the analysis of the impact of gestational age yielded inconsistent results.This finding is consistent with the concept of fetal programming of the HPA axis and provides the first preliminary evidence for an association between birth weight and adrenocortical responses to psychosocial stress. As the investigated subjects were twins, possible implications of this sample characteristic for the present findings are discussed

Comparison of laser welding and electron beam welding technology

Práce předkládá porovnání a technické hodnocení dvou technologií svařování – tedy nerozebíratelného spojení dvou materiálu, v našem případě superslitiny Inconel 718. Na základě technologického parku společnosti Honeywell Aerospace Olomouc, s.r.o přichází v úvahu dosud používaný způsob svařování svazkem elektorů, který je v této práci porovnáván se svařováním laserem z důvodu jeho rychlosti svařování a malého vneseného tepla během svařovacího procesu.Thesis presents a comparison of technical evaluation of two welding technologies – dismountable connection of two materials, in this case superalloy Inconel 718. On the basis of the technological park of Honeywell Aerospace Olomouc s.r.o. coming into consideration still used the electron beam welding method which is compared in this work with the laser welding due to speed up the welding and a little heat input during the process of the welding.

Association of a polymorphism in the H6PD gene and basal cortisol secretion, body fat mass and leptin level (Assoziation eines Polymorphismus im H6PD Gen mit basaler Cortisolsekretion, Fettmasse und Leptinwerten)

The hypothalamus-pituitary-adrenal (HPA) axix is vital for an organism's response to physical or psychosocial stimulation. Chronic dysregulation of HPA axis activity is related to several psychiatric and psychosomatic disorders. Cortisol, the end product of this endocrine system, affects a multitude of systems in the body, including the HPA axis itself and it also has an influence on behavior. The intracellular availability of cortisol is crucial for the regulation of this endocrine system. The enzyme hexose-6-phosphat-dehydrogenase (H6PDH) affects cortisol availability via its influenec on 11?-hydroxysteroid dehydrogenase type I (11?-HSDI)-activity, which regenerates cortisol from inactive cortisone. 116 healthy males (33 monozygotic &amp; 25 dizygotic twin pairs) were studied to estimate the association between a polymorphism in the exon 5 of the H6PD gene (R435Q, GA) and adrenocortical responses to psychosocial stress, basal salivary cortisol levels and body composition. Compared with subjects with the more frequent H6PD genotypers the homozygous AA-carriers displayed a significantly decreased cortisol awakening rise (CAR) as well as lower daytime cortisol levels. In response to stress, the AA-carriers exhibited a trend towards lower cortisol and ACH responses compared with GG- and GA-carriers. In addition, significantly higher levels of leptin and amount of body fat were observed in AA-carriers. We hypothesize that the R453Q polymorphism in the H6PD gene might influence intracellular cortisol availability and thus affect HPA axis regulation.<br/

Common polymorphisms in the glucocorticoid receptor gene are associated with adrenocrticol responses to psychosocial stress

Chronic dysregulation of hypothalamus-pituitary-adrenal axis activity is related to several stress-related disorders. Evidence suggests that polymorphisms in the glucocorticoid receptor (GR) gene may have an impact on this neuroendocrine system. In the present investigation, 112 healthy males were studied to estimate the impact of three GR gene polymorphisms (BclI RFLP, N363S, ER22/23EK) on cortisol and ACTH responses to psychosocial stress (Trier Social Stress Test) and pharmacological stimulation (1 µg ACTH1–24, 0.5 mg dexamethasone). Because only four ER22/23EK heterozygotes were identified, these subjects were not statistically analyzed. Compared with subjects with the wild-type GR genotype (n = 36), 363S allele carriers (n = 10) showed significantly increased salivary cortisol responses to stress, whereas the BclI genotype GG (n = 18) was associated with a diminished cortisol response. BclI heterozygotes and homozygotes (GG) exhibited a trend toward lower ACTH responses, compared with wild-type subjects and 363S carriers. The cortisol response to ACTH1–24 administration was not significantly different between genotypes. After dexamethasone ingestion, 363S carriers showed a trend toward an enhanced cortisol suppression. This is the first report documenting an impact of GR gene polymorphisms on cortisol (and perhaps ACTH) responses to psychosocial stress. These variants may contribute to the individual vulnerability for hypothalamus-pituitary-adrenal-related disorders