Microvascular System of the Human Fetal Inner Ear: A Scanning Electron Microscopic Study of Corrosion Casts

The vascular system of the inner ear was investigated in 18-21 weeks old human fetuses, using the corrosion cast technique in scanning electron microscopy. At that developmental stage, vascularization of the cochlea and semicircular canals shows a pattern very similar to that described for adults. The most important differences which can be regarded as fetal features include: (1) denser limbus vessels, (2) the marginal vessels of the spiral lamina appearing as irregular network which shows a less clear arcade-like arrangement, (3) some radiating arterioles of the spiral lamina and marginal vessels possessing connections with the vascular system of the external wall, and (4) a dense, sinusoidal network of draining venules at scala tympani. These features apparently disappear during the final remodelling of the inner ear microvasculature in the last trimester

Application of a mixture of glycol polyethylenes for the preparation of microcorrosion casts - an observation

Preparation of microcorrosion casts that can be used for observation in SEM is a laborious, time-consuming procedure. The authors paid particular attention to the process of dissection of the microcorrosion casts. This prompted the authors to reconstruct the plastic mass, produced by the firm Gurr (Great Britain) in the 1970s, which was used by them in previous research to immerse the cast in order to minimise the damage. By using easily obtainable polyethylene glycols, characterised by different physical and chemical features, in order to obtain smooth surface of the section, a low-toxic mixture was composed, which protected the microcorrosion casts sufficiently and did not interfere with the physical and chemical properties of the cast

Apatite from NWA 10153 and NWA 10645 : the key to deciphering magmatic and fluid evolution history in Nakhlites

Apatites from Martian nakhlites NWA 10153 and NWA 10645 were used to obtain insight into their crystallization environment and the subsequent postcrystallization evolution path. The research results acquired using multi-tool analyses show distinctive transformation processes that were not fully completed. The crystallization history of three apatite generations (OH-bearing, Cl-rich fluorapatite as well as OH-poor, F-rich chlorapatite and fluorapatite) were reconstructed using transmission electron microscopy and geochemical analyses. Magmatic OH-bearing, Cl-rich fluorapatite changed its primary composition and evolved toward OH-poor, F-rich chlorapatite because of its interaction with fluids. Degassing of restitic magma causes fluorapatite crystallization, which shows a strong structural affinity for the last episode of system evolution. In addition to the three apatite generations, a fourth amorphous phase of calcium phosphate has been identified with Raman spectroscopy. This amorphous phase may be considered a transition phase between magmatic and hydrothermal phases. It may give insight into the dissolution process of magmatic phosphates, help in processing reconstruction, and allow to decipher mineral interactions with hydrothermal fluids

Regulation of activity and localization of the WNK1 protein kinase by hyperosmotic stress

Mutations within the WNK1 (with-no-K[Lys] kinase-1) gene cause Gordon's hypertension syndrome. Little is known about how WNK1 is regulated. We demonstrate that WNK1 is rapidly activated and phosphorylated at multiple residues after exposure of cells to hyperosmotic conditions and that activation is mediated by the phosphorylation of its T-loop Ser382 residue, possibly triggered by a transautophosphorylation reaction. Activation of WNK1 coincides with the phosphorylation and activation of two WNK1 substrates, namely, the protein kinases STE20/SPS1-related proline alanine–rich kinase (SPAK) and oxidative stress response kinase-1 (OSR1). Small interfering RNA depletion of WNK1 impairs SPAK/OSR1 activity and phosphorylation of residues targeted by WNK1. Hyperosmotic stress induces rapid redistribution of WNK1 from the cytosol to vesicular structures that may comprise trans-Golgi network (TGN)/recycling endosomes, as they display rapid movement, colocalize with clathrin, adaptor protein complex 1 (AP-1), and TGN46, but not the AP-2 plasma membrane–coated pit marker nor the endosomal markers EEA1, Hrs, and LAMP1. Mutational analysis suggests that the WNK1 C-terminal noncatalytic domain mediates vesicle localization. Our observations shed light on the mechanism by which WNK1 is regulated by hyperosmotic stress

The novel gene Ny-1 on potato chromosome IX confers hypersensitive resistance to Potato virus Y and is an alternative to Ry genes in potato breeding for PVY resistance

Hypersensitive resistance (HR) is an efficient defense strategy in plants that restricts pathogen growth and can be activated during host as well as non-host interactions. HR involves programmed cell death and manifests itself in tissue collapse at the site of pathogen attack. A novel hypersensitivity gene, Ny-1, for resistance to Potato virus Y (PVY) was revealed in potato cultivar Rywal. This is the first gene that confers HR in potato plants both to common and necrotic strains of PVY. The locus Ny-1 mapped on the short arm of potato chromosome IX, where various resistance genes are clustered in Solanaceous genomes. Expression of HR was temperature-dependent in cv. Rywal. Strains PVYO and PVYN, including subgroups PVYNW and PVYNTN, were effectively localized when plants were grown at 20°C. At 28°C, plants were systemically infected but no symptoms were observed. In field trials, PVY was restricted to the inoculated leaves and PVY-free tubers were produced. Therefore, the gene Ny-1 can be useful for potato breeding as an alternative donor of PVY resistance, because it is efficacious in practice-like resistance conferred by Ry genes

Mer receptor tyrosine kinase mediates both tethering and phagocytosis of apoptotic cells

Billions of inflammatory leukocytes die and are phagocytically cleared each day. This regular renewal facilitates the normal termination of inflammatory responses, suppressing pro-inflammatory mediators and inducing their anti-inflammatory counterparts. Here we investigate the role of the receptor tyrosine kinase (RTK) Mer and its ligands Protein S and Gas6 in the initial recognition and capture of apoptotic cells (ACs) by macrophages. We demonstrate extremely rapid binding kinetics of both ligands to phosphatidylserine (PtdSer)-displaying ACs, and show that ACs can be co-opsonized with multiple PtdSer opsonins. We further show that macrophage phagocytosis of ACs opsonized with Mer ligands can occur independently of a requirement for αV integrins. Finally, we demonstrate a novel role for Mer in the tethering of ACs to the macrophage surface, and show that Mer-mediated tethering and subsequent AC engulfment can be distinguished by their requirement for Mer kinase activity. Our results identify Mer as a receptor uniquely capable of both tethering ACs to the macrophage surface and driving their subsequent internalization

Separation and characterization of the silt fraction in the mudstone rocks of the Carpathian Foredeep

Skały mułowcowe, pomimo że zawierają znacznie mniej minerałów ilastych niż iłowce, to na krzywych otworowych mają podobnypoziom radioaktywności, co istotnie utrudnia wydzielenie ich z analizowanego profilu litologicznego. Celem przedstawionych badań jest opracowanie metodyki pozwalającej na wydzielenie, charakterystykę i oszacowanie ilościowego udziału frakcji pylastej (silt) w skałach mułowcowych. Przetestowane zostały różne laboratoryjne metody rozdrabniania skał (kruszenie, zamrażanie, nasycanie solą glauberską) tak, aby uniknąć sztucznego utworzenia dodatkowego siltu (np. przez zbytnie rozkruszenie skały), jak i zaniżenia jego ilości (przez niedostateczne rozdrobnienie skały). Poszczególne frakcje ziarnowe zostały wydzielone w rozdrobnionym materiale skalnym metodą sitową (frakcja piaszczysta) oraz metodą wirowania (frakcja pylasta, frakcja ilasta). Następnie przeprowadzono dokładną charakterystykę mineralogiczną i petrofizyczną oraz dokonano oceny ilościowej wydzielonej frakcji pylastej. Wydzielenie frakcji pylastej badanych skał i uwzględnienie jej w modelach interpretacyjnych umożliwia rozróżnienie mułowców i iłowców w profilach otworów wiertnicznych zapadliska przedkarpackiego.Mudstones, although they contain significantly less clay minerals than claystones, they exhibit similar levels of radioactivity on the well logs, which significantly impedes their distinction in the analyzed lithological profile. The aim of the study was to develop a methodology for separating, characterizing, and estimating the amount of silt fraction in mudstone rocks. Various laboratory methods of fragmentation (crushing, freezing, saturation with Glauber’s salt) have been tested to avoid both creating additional silt artificially (e.g. by over-crushing the rock), and underestimating of its amount (by insufficient fragmentation of rocks). The individual grain fractions were separated in the crushed rock material by the sieve (sand fraction) and centrifugation methods (silt fraction, clay fraction). Subsequently the detailed mineralogical and petrophysical characteristics and quantitative evaluation of the silt fraction were carried out. The separation of the silt fraction in the examined rock and its inclusion in the interpretation models will allow to distinguish between mudstones and claystones in the profiles of the Carpathian Foredeep boreholes