Talajok környezet-geokémiai folyamatainak vizsgálata = Environmental geochemical study of soils

A Veszprémi Pannon Egyetemen több mint két évtizede folynak hazánk valamennyi típustalajára kiterjedő talajásványtani, talajgenetikai és környezet-geokémiai kutatások. Ezúttal humuszkarbonát-talajt, rendzina-talajt, valamint barna erdőtalajt vizsgáltunk. Új talajvizsgálati módszert alkalmaztunk, mely lehetővé teszi, hogy ne egy statikus állapotot rögzítsünk, hanem az ásványi átalakulások folyamatátnis figyelemmel kísérhessük. A módszer kulcsfontosságú lépése a szemcsefrakciók szerinti vizsgálat. A kutatás kiterjedt a humusz-tartalom és nyomelemek közötti kapcsolatot, valamint a jellemző ásványos fázisok anyomelemek közötti kapcsolat tanulmányozására. A szemcsefrakciókra a következők: 800 um. XRD és XRFS módszereket alkalmazva meghatároztuk a minták ásványi és kémiai összetételét, nyomelemeinek koncentrációit. Vizsgálatainkat SEM, TEM és derivatográfiás mérésekkel egészítettük ki. Megállapítottuk, hogy talajtípustól és mélységtől függetlenül a rezisztens ásványok ásványok (kvarc, földpát, muszkovit, klorit, dolomit)mennyisége a kis szemcseméret felé egy vagy két maximum után csökken, az autigén képződményeké pedig (montmorillonit, amorf anyag) jelentősen növekszik. Az ásványok átalakulásával kapcsolatban olyan összefüggésekre világítottunk rá, amelyek a laboratóriumban mért és a természetben megfigyelhető jelenségek ellentmondásaira adnak magyarázatot. | At the Pannon University Veszprem the mineralogy, genesis and environmental geochemistry of soils that formed on various types of rocks was studied. A new, dynamic method was used, in order to understand the processes of mineral transformations. An essential feature of the applied method is the analysis of distinct size fractions. Samples were collected at 10 cm depth intervals and separated into the size fractions of 800 um. The mineralogical and chemical compositions (including trace element compositions) were determined using XRD and XRFS metods respectively. Additionally SEM, TEM and derivatography were performed. In addition to identifying the weathering processes, we also determined relationships between humus content and trace elements, and between characteristic mineral phases and trace element concentrations. The organic carbon content of the soil was determined using TOC analysis. It was found that the amount of resistant minerals (quartz, feldspar, muscovite, chlorite, dolomite) decreases, whereas the concentration of authigenic substances (montmorillonite, amorphous matter) increases towards smaller grain sizes, independent of the soil type and sample depth. With respect to mineral transformations, we highlight some features that may explain discrepancies between the results of laboratory and field measurement

The Distinct Effects of Palmitic and Oleic Acid on Pancreatic Beta Cell Function: The Elucidation of Associated Mechanisms and Effector Molecules

In this study, we aimed to identify the mechanisms underlying the different effects of palmitic acid and oleic acid on human pancreatic beta cell function. To address this problem, the oxidative stress, endoplasmic reticulum stress, inflammation, apoptosis and their mediator molecules have been investigated in the insulin releasing beta cells exposed to palmitic and/or oleic acid. Herein, we have demonstrated that in cultured 1.1B4 beta cells oleic acid promotes neutral lipid accumulation and insulin secretion, whereas palmitic acid is poorly incorporated into triglyceride and it does not stimulate insulin secretion from human pancreatic islets at physiologically glucose concentrations. In addition, palmitic acid caused: (1) oxidative stress through a mechanism involving increases in ROS production and MMP-2 protein expression/gelatinolytic activity associated with down-regulation of SOD2 protein; (2) endoplasmic reticulum stress by up-regulation of chaperone BiP protein and unfolded protein response (UPR) transcription factors (eIF2α, ATF6, XBP1u proteins) and by PTP-1B down-regulation in both mRNA and protein levels; (3) inflammation through enhanced synthesis of proinflammatory cytokines (IL6, IL8 proteins); and (4) apoptosis by enforced proteic expression of CHOP multifunctional transcription factor. Oleic acid alone had opposite effects due to its different capacity of controlling these metabolic pathways, in particular by reduction of the ROS levels and MMP-2 activity, down-regulation of BiP, eIF2α, ATF6, XBP1u, CHOP, IL6, IL8 and by SOD2 and PTP-1B overexpression. The supplementation of saturated palmitic acid with the monounsaturated oleic acid reversed the negative effects of palmitic acid alone regulating insulin secretion from pancreatic beta cells through ROS, MMP-2, ATF6, XBP1u, IL8 reduction and SOD2, PTP-1B activation. Our findings have shown the protective action of oleic acid against palmitic acid on beta cell lipotoxicity through promotion of triglyceride accumulation and insulin secretion and regulation of some effector molecules involved in oxidative stress, endoplasmic reticulum stress, inflammation and apoptosis

Part One: Extracellular Vesicles as Valuable Players in Diabetic Cardiovascular Diseases

Extracellular vesicles (EVs) are particles released in the extracellular space from all cell types in physiological and pathological conditions and emerge as a new way of cell-cell communication by transferring their biological contents into target cells. The levels and composition of circulating EVs differ from a normal condition to a pathological one, making them real circulating biomarkers. EVs have a very complex contribution in both health and disease, most likely in relationship between diabetes and cardiovascular disease. The involvement of EVs to the development of cardiovascular complications in diabetes remains an open discussion for therapists. Circulating EVs may offer a continuous access path to circulating information on the disease state and a new perspective in finding a correct diagnosis, in estimating a prognosis and also in applying an effective therapy. Besides their role as biomarkers and targets for therapy, EVs can be exploited as biological tools in influencing the different processes affected in diabetic cardiovascular diseases. This chapter will summarize the current knowledge about EVs as biological vectors modulating diabetic cardiovascular diseases, including atherosclerosis, coronary artery disease, and peripheral arterial disease. Finally, we will point out EVs’ considerable value as clinical biomarkers, therapeutic targets, and potential biomedical tools for the discovery of effective therapy in diabetic cardiovascular diseases