50 research outputs found
Preliminary studies of sediments from the Dobczyce drinking water reservoir
The analysis of river and lake sediments indicates that the physical, chemical, biochemical and geochemical
processes that influence the fate of toxic compounds and elements in sediments are numerous and complex
(for example: sorption - desorption, oxidation - reduction, ion-exchange, biological activity). Due to the
above-mentioned general statement, only a long term and complex research programme can lead to satisfactory
answers to the questions relating to possible changes of water and environmental quality in the future.
The aim of our study consisted in physical and chemical characterisation of sediments in in-depth profiles
taken from the Dobczyce reservoir in southern Poland that is a main source of drinking water for the city
of Kraków. Due to morphological reasons, 7 layers of sediment samples were distinguished from the ground
level to about 90 cm below (total thickness of the sediments in the sampling site). Analysis of grain size distribution
and application of x-ray diffraction method, enabled mineralogical description of sediments.
The use of proton-induced x-ray emission (PIXE) and atomic absorption spectrometry (AAS) revealed
elemental composition of the samples (Al, P, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn). Concentrations
of natural 40K and artificial 137Cs radionuclides were determined by the use of gamma spectrometry.
The following facts were established: 1) the oldest (deepest) and newest, recently deposited layers of
sediments are similar in their physical and chemical properties. It means that the inflow of contaminants
and biogenic compounds to the reservoir has changed little since it was constructed and filled with water;
2) the severe flood in 1997 changed significantly sediment composition and, in fact, led to purification of
sediments in the Dobczyce reservoir
The effect of pre-incubation of Allium cepa L. roots in the ATH-rich extract on Pb uptake and localization
The positive influence of anthocyanin (ATH) on toxic metal-treated plant material is well documented; however, it is still not explained if it is caused by changes in element absorption and distribution. Therefore, detailed analysis of the effect of the ATH-rich extract from red cabbage leaves on Pb uptake and localization at morphological, anatomical and ultrastructural level was the goal of this study. Two-day-old adventitious roots of Allium cepa L. (cv. Polanowska) were treated for 2 h with the aqueous solution of Pb(NO3)2 at the concentration of 100 μM with or without preliminary incubation in the anthocyanin-rich extract from Brassica oleracea L. var. capitata rubra leaves (250 μM, 3 h). The red cabbage extract did not change the total Pb uptake but it enhanced the translocation of accumulated metal from roots to shoots. Within the pretreated roots, more Pb was deposited in their basal part and definitely smaller amount of the metal was bound in the apoplast of the outer layers of cortex cells. The ultrastructural analysis (transmission electron microscopy and X-ray microanalysis) revealed that the ATH-rich extract lowered the number of Pb deposits in intracellular spaces, cell wall and cytoplasm of root meristematic cells as well as in such organelles important to cell metabolism as mitochondria, plastids and nucleus. The Pb deposits were preferably localised in those vacuoles where ATH also occurred. This sequestration of Pb in vacuoles is probably responsible for reduction of metal cytotoxicity and consequently could lead to better plant growth.This work was supported by the grant of the
University of Lodz, no. 505/04038
WRN Mutation Update: Mutation Spectrum, Patient Registries, and Translational Prospects
Werner syndrome (WS) is a rare autosomal recessive disorder characterized by a constellation of adult onset phenotypes consistent with an acceleration of intrinsic biological aging. It is caused by pathogenic variants in the WRN gene, which encodes a multifunctional nuclear protein with exonuclease and helicase activities. WRN protein is thought to be involved in optimization of various aspects of DNA metabolism, including DNA repair, recombination, replication, and transcription. In this update, we summarize a total of 83 different WRN mutations, including eight previously unpublished mutations identified by the International Registry of Werner Syndrome (Seattle, WA) and the Japanese Werner Consortium (Chiba, Japan), as well as 75 mutations already reported in the literature. The Seattle International Registry recruits patients from all over the world to investigate genetic causes of a wide variety of progeroid syndromes in order to contribute to the knowledge of basic mechanisms of human aging. Given the unusually high prevalence of WS patients and heterozygous carriers in Japan, the major goal of the Japanese Consortium is to develop effective therapies and to establish management guidelines for WS patients in Japan and elsewhere. This review will also discuss potential translational approaches to this disorder, including those currently under investigation