Prenatal Glucocorticoids: Short-Term Benefits and Long-Term Risks

Glucocorticoids are steroid hormones synthesized in the adrenal gland cortex, and most of their physiological effects are mediated by the glucocorticoid receptor (GR), that acts as a ligand-dependent transcription factor. Coordinate changes in metabolism under glucocorticoid influence provide energy that is instantly and selectively available to vital organs, an enables them to deal with immediate environmental demands, at the expense of anabolic pathways, such as bone formation, reproduction, immunological responses and other, that are being blunted or delayed, under glucocorticoid influence [1-3]. During fetal development the synthesis of adrenal glucocorticoids precedes the establishment of a definitive structure of the gland. In rats, secretion of the main glucocorticoid – corticosterone starts as early as on day 13 of development [4] (term=22 days, short gestation period), while in humans secretion of the main glucocorticoid – cortisol starts in the 8th week of pregnancy (term=40 weeks, long gestation period) [5]. Glucocorticoid receptor mRNA is present in the tissue derivatives of all three germ layers from fetal day 13 onwards, and increases gradually during rat fetal development [6]. Human fetal tissues express GR at the gestational age of 6 weeks, meaning that the machinery for hormone action is prepared at the early stages of development [5]. These facts suggest that endogenous glucocorticoids produced by the fetal adrenal glands have a crucial role in fetal growth and the development of individual fetal tissues [7]. In response to the prepartum rise in glucocorticoids a wide variety of changes known as “preparation for birth” occurs, meaning that the maturational changes in many fetal tissues, essential for neonatal survival, are intensified during the last third of gestation. Namely, circulating glucocorticoids induce fetal lung maturation and surfactant production, trigger a variety of physiological effects on brain cell differentiation and synaptogenesis, stimulate the production of hepatic gluconeogenic enzymes, affect pancreatic -cell development and insulin content, influence renal development and affect the maturation of the immune system [8-10]. Metabolic, cardiovascular and immune adaptations under glucocorticoid influence are fundamental to successfully overcoming birth-related stress and postnatal adaptation of the newborn to environmental challenges [11, 12]. Environmental conditions influence the prevailing nutritional and endocrine status in mothers and fetuses. Numerous animal and human studies have shown that adverse environmental conditions during pregnancy, such as maternal undernutrition [13, 14], stress [15, 16], illness, placental insufficiency [17, 18], as well as prenatal glucocorticoid exposure [19, 20] affect fetal development and postnatal outcome. Changes in the maternal hypothalamic-pituitary-adrenal (HPA) activity, transplacental diffusion of nutrients, hormones and growth factor supply, potently affect the fetal HPA axis influencing glucocorticoid output as well as other developing systems [21, 22]. Gestational age, at which an insult occurs, its nature and intensity, determines the specific tissue or organ which will be affected by the insult. Glucocorticoids are the key mediators between maternal environment and the fetus, and as such are involved in adaptations of the fetus to predicted postnatal environment. Even transient changes in glucocorticoid levels could have longlasting consequences. The outcome might be growth retardation and change in the developmental trajectory, in the direction that best suited to the expected environment [23, 24]. This phenomenon is known as programming. The adaptations caused by suboptimal intrauterine conditions are appropriate if the predicted and actual postnatal environments match, and lead to survival to reproduce in a deprived environment [25, 26]. If there is a mismatch between the environment predicted and the actual environment experienced postnatally, adaptations are inappropriate and result in the development of disease like hypertension, ischemic heart disease, glucose intolerance, insulin resistance and type 2 diabetes [27-29]. In this chapter the latest findings, with clear statements from the literature, as well as own results regarding the endocrine mechanisms of intrauterine programming mediated by glucocorticoids will be analyzed. The causal relationship between a prenatally programmed endocrine axes and their postnatal functioning that affect growth, stress response, metabolism and reproduction will be discussed. In order to better understand mechanisms of fetal glucocorticoid programming of endocrine axes, special attention will be paid to key points of their development

Nanocomposites with antimicrobial properties synthesized by photoreduction of silver ions on the surface of differently shaped titanium(IV)-oxide nanocrystals deposited on textile materials.

Doktorska disertacija je imala za cilj sintezu i karakterizaciju nanokompozita koji poseduju antimikrobna svojstva inovativnom metodom in situ fotoredukcije Ag+-jona na površini nanokristala TiO2 različitih oblika, prethodno deponovanih na tekstilnim materijalima. Ovakav pristup sintezi nanokompozitnih tekstilnih materijala je po prvi put realizovan u okviru ove teze...This doctoral thesis relates to the synthesis and characterization of advanced nanocomposites which exhibit antimicrobial activity and UV protective properties. For the synthesis an innovative method based on in situ photoreduction of Ag+-ions onto the surface of differently shaped TiO2 nanocrystals, being in the form of either spherical nanoparticles or nanotubes, deposited on different textile materials was applied. Such synthesis route for the formation of textile nanocomposites has been realized for the first time in the context of this thesis..

Utilization of soy hull for production of pectic fiber

Soy hull, a by-product of soybean processing, was investigated as a source of pectic fiber. Pectic fiber was obtained with yield of 5.72 g/100 gDW. Soy hull pectic fiber demonstrated good solubility (83.49%) and high molecular weight with Mw of dominant fraction 3192.6 kDa. These favorable characteristics could indicate a great potential for application in food industry

Recovery and functional properties of rubisco protein from conventional and enzymatic extractions

Protein isolates extracted by conventional and enzymatic protocols from pumpkin leaves were evaluated. Pumpkin leaves represent waste material that can be used for extraction of RuBisCO protein. Results showed that usage of Viscozyme for enzyme-assisted extraction enhanced recovery of protein by 30% compared to conventional extraction protocol. Moreover, protein extracted by enzymatic treatment showed improved solubility and oil holding capacity by 71% and 13%, respectively. Our findings might indicate a possibility of usage of enzyme treatment that would enable production of protein isolate with properties and/or in quantities tailored to their particular application in food systems

Inhibitory effect of SRIH-14 on ACHT cells in neonatal female rats

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