Selenium and its compounds – Determination of total selenium in urine by ICP-MS

The working group “Analyses in Biological Materials” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area developed and verified the presented biomonitoring method. Selenium is used in different industrial processes. In the workplace, employees are mainly exposed to elementary selenium and inorganic selenium compounds. In contrast, the non-occupationally exposed general population ingests mainly organic selenium compounds, like selenomethionine and selenocysteine, via the diet. Following exposure, selenium can be determined in serum/plasma and in whole blood/erythrocytes. While the selenium concentrations in these matrices reflect exposure from recent weeks or even months, urinary selenium concentrations are suitable for the determination of short-term exposure (e.g. of the last shift). The aim of this work was to develop a selective method for the determination of total selenium in urine while avoiding the selenium enhancement effect caused by volatile selenium species (e.g. dimethyl selenide or dimethyl diselenide). The method has been comprehensively verified, and the reliability data have been confirmed by replication and verification of the procedure in a second, independent laboratory. Urine samples are mineralised by microwave-assisted digestion using an acidic hydrogen peroxide-containing solution, thereby converting the various selenium species present in the urine into selenite. The selenium concentrations in the diluted digestion solutions are determined by mass spectrometry with inductively coupled plasma (ICP-MS) on m/z = 78. Germanium is used as internal standar

Selen und seine Verbindungen – Bestimmung von Selen (gesamt) in Urin mittels ICP-MS

The working group “Analyses in Biological Materials” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area developed and verified the presented biomonitoring method. Selenium is used in different industrial processes. In the workplace, employees are mainly exposed to elementary selenium and inorganic selenium compounds. In contrast, the non-occupationally exposed general population ingests mainly organic selenium compounds, like selenomethionine and selenocysteine, via the diet. Following exposure, selenium can be determined in serum/plasma and in whole blood/erythrocytes. While the selenium concentrations in these matrices reflect exposure from recent weeks or even months, urinary selenium concentrations are suitable for the determination of short-term exposure (e.g. of the last shift). The aim of this work was to develop a selective method for the determination of total selenium in urine while avoiding the selenium enhancement effect caused by volatile selenium species (e.g. dimethyl selenide or dimethyl diselenide). The method has been comprehensively verified, and the reliability data have been confirmed by replication and verification of the procedure in a second, independent laboratory. Urine samples are mineralised by microwave-assisted digestion using an acidic hydrogen peroxide-containing solution, thereby converting the various selenium species present in the urine into selenite. The selenium concentrations in the diluted digestion solutions are determined by mass spectrometry with inductively coupled plasma (ICP-MS) on m/z = 78. Germanium is used as internal standard. The microwave-assisted digestion allows for the accurate quantification of total selenium in urine even when volatile selenium species are present in the samples

Finding the Area of Origin of the Horse-Chestnut Leaf Miner : a Challenge

CABI Bioscience Switzerland centreTechnological Educational Institution of KavalaInstitute of Animal EcologyUniversity pf Natural Resources and Applied Life Sciences, Institute of Plant ProtectionUniversity of SopronInstitute of ZoologyInstitute of Organic Chemistry and BiochemistryUniversity of ForestryProceedings : IUFRO Kanazawa 2003 "Forest Insect Population Dynamics and Host Influences"., Scedule:14－19 September 2003, Vemue: Kanazawa Citymonde Hotel, Kanazawa, Japan, Joint metting of IUFRO working groups : 7.01.02 Tree resistance to Insects | 7.03.06 Integrated management of forset defoloating insects | 7.03.07 Population dynamics of forest insects, Sponsored by: IUFRO-J | Ishikawa Prefecture | Kanazawa City | 21st-COE Program of Kanazawa University, Editors: Kamata, Naoto | Liebhold, Nadrew M. | Quiring, Dan T. | Clancy, Karen M

Composition of abyssal macrofauna along the Vema Fracture Zone and the hadal Puerto Rico Trench, northern tropical Atlantic

We analyzed composition and variations in benthic macrofaunal communities along a transect of the entire length of the Vema-Fracture Zone on board of RV Sonne (SO-237) between December 2014 and January 2015 in order to test whether the Mid-Atlantic Ridge serves as a barrier limiting benthic taxon distribution in the abyssal basins on both sides of the ridge or whether the fracture zone permits the migration of species between the western and eastern abyssal Atlantic basins. The Puerto Rico Trench, much deeper than the surrounding abyssal West Atlantic, was sampled to determine whether the biodiversity of its hadal macrofauna differs from that of the abyssal Atlantic. The composition of the macrofauna from the epibenthic sledge catches yielded a total of 21,332 invertebrates. Crustacea occurred most frequently (59%) with 12,538 individuals followed by Annelida (mostly Polychaeta) (26%) with 5,491 individuals, Mollusca (7%) with 1,458 individuals, Echinodermata (4%) with 778 individuals, Nematoda (2%) with 502 individuals and Chaetognatha (1%) with 152 and Porifera (1%) with 131 individuals. All other taxa occurred with overall less than ten individuals (Hemichordata, Phoronida, Priapulida, Brachiopoda, invertebrate Chordata, Echiurida, Foraminifera (here refereed to macrofaunal Komokiacea only), Chelicerata, Platyhelminthes). Within the Crustacea, Peracarida (62.6%) with 7,848 individuals and Copepoda (36.1%) with 44,526 individuals were the most abundant taxa. Along the abyssal Vema-Fracture Zone macrofaunal abundances (ind./1,000 m2) were generally higher on the eastern side, while the highest normalized abundance value was reported in the Puerto Rico Trench at abyssal station 14-1 2,313 individuals/1,000 m2. The lowest abundance was reported at station 11-4 with 120 ind./1,000 m2 located at the western side of the Vema-Fracture Zone. The number of major macrofaunal taxa (phylum, class) ranged between five (stations 12-5, 13-4 and 13-5 at hadal depths in the Puerto Rico Trench) and 14 (station 9-8) in the western abyssal basin of the Vema-Fracture Zone. Differences are seen in the distribution of Porifera at macrofaunal level between eastern and western sides of the Vema-Fracture Zone. Macrofaunal composition of the study area is compared with data from other expeditions in the Atlantic and the northwest Pacific Ocean

Comparison between human fetal and adult skin

Healing of early-gestation fetal wounds results in scarless healing. Since the capacity for regeneration is probably inherent to the fetal skin itself, knowledge of the fetal skin composition may contribute to the understanding of fetal wound healing. The aim of this study was to analyze the expression profiles of different epidermal and dermal components in the human fetal and adult skin. In the human fetal skin (ranging from 13 to 22 weeks’ gestation) and adult skin biopsies, the expression patterns of several epidermal proteins (K10, K14, K16, K17, SKALP, involucrin), basement membrane proteins, Ki-67, blood vessels and extracellular matrix proteins (fibronectin, chondroitin sulfate, elastin) were determined using immunohistochemistry. The expression profiles of K17, involucrin, dermal Ki-67, fibronectin and chondroitin sulfate were higher in the fetal skin than in adult skin. In the fetal skin, elastin was not present in the dermis, but it was found in the adult skin. The expression patterns of basement membrane proteins, blood vessels, K10, K14, K16 and epidermal Ki-67 were similar in human fetal skin and adult skin. In this systematic overview, most of the differences between fetal and adult skin were found at the level of dermal extracellular matrix molecules expression. This study suggests that, especially, dermal components are important in fetal scarless healing

Applicability of non-invasively collected matrices for human biomonitoring

With its inclusion under Action 3 in the Environment and Health Action Plan 2004–2010 of the European Commission, human biomonitoring is currently receiving an increasing amount of attention from the scientific community as a tool to better quantify human exposure to, and health effects of, environmental stressors. Despite the policy support, however, there are still several issues that restrict the routine application of human biomonitoring data in environmental health impact assessment. One of the main issues is the obvious need to routinely collect human samples for large-scale surveys. Particularly the collection of invasive samples from susceptible populations may suffer from ethical and practical limitations. Children, pregnant women, elderly, or chronically-ill people are among those that would benefit the most from non-invasive, repeated or routine sampling. Therefore, the use of non-invasively collected matrices for human biomonitoring should be promoted as an ethically appropriate, cost-efficient and toxicologically relevant alternative for many biomarkers that are currently determined in invasively collected matrices. This review illustrates that several non-invasively collected matrices are widely used that can be an valuable addition to, or alternative for, invasively collected matrices such as peripheral blood sampling. Moreover, a well-informed choice of matrix can provide an added value for human biomonitoring, as different non-invasively collected matrices can offer opportunities to study additional aspects of exposure to and effects from environmental contaminants, such as repeated sampling, historical overview of exposure, mother-child transfer of substances, or monitoring of substances with short biological half-lives