Flora des Neutraer Comitates

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Apoptosis and cell death in neuronal cells: where does Ca fit in?

Mounting evidence shows that neuronal death is an important and essential component of brain tissue homeostasis, with two major forms of cell death occurring: necrosis and apoptosis. No general consensus exists as to whether these two forms of neuronal death represent separate cellular processes or just two different forms of a common ‘death pathway’. One difference between them is the role played by intracellular Ca²⁺: central and obligatory, in necrosis and possible, but not always necessary in triggering apoptosis. Furthermore, the same assessment of the involvement of Ca²⁺ signalling could also distinguish between two poss ible apoptotic states in the nervous system: one, the ‘developmental apoptosis’, involving immature and developing neurons, in which Ca²⁺ plays mainly an apoprotector role, and another one, associated mainly with pathological instances and involving fully matured and established neurons, in which Ca²⁺ plays an apo-inducing role.     

Using multiple satellite observations to quantitatively assess and model oil pollution and predict risks and consequences to shoreline from oil platforms in the Caspian Sea

This research focused on the following objectives: (1) using satellite data to characterize the spatiotemporal distribution of anthropogenic oil spills from Oil Rocks Settlement, Chilov and Pirallahi Islands (2) stochastic modeling of the oil spill risk pose to water quality and shoreline ecosystems, and (3) validating model predictions using satellite images. 165 satellite images acquired by SENTINEL-1A, LANDSAT-8, RADARSAT, ENVISAT and ERS sensors between 1996 and 2015 were used for the detection of oil spills using object-based classification and visual interpretation. Anthropogenic hotspots were observed at three oldest oil production sites with estimated oil spilling up to 1264 m³ per day and different degrees of temporal repetition of oil spills. The largest area (5639 km²) experienced 1–10 detected oil spills, while 993 km² experienced 11–20 oil spills, 775 km² experienced 21–50 oil spills, 208 km² experienced 51–100 oil spills, and 36 km² experienced 101–150 oil spills. The majority (83% or 6157 km²) of sea surface area within the combined boundary of detected oil spills (7422 km²) had a 50% or greater chance of oil spill contamination. Approximately, 6% (44 km of 751 km) of shoreline had a 50% or greater probability of contamination with land use classes sensitive to pollution.     

Über eine merkwürdige anatomische Veränderung in der Trennungsschichte bei der Ablösung der Blätter

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Ontogeny of melatonin, Per2 and E4bp4 light responsiveness in the chicken embryonic pineal gland.

The chicken pineal gland possesses the capacity to generate circadian oscillations, is able to synchronize to external light:dark cycles and can generate an hormonal output--melatonin. We examined the light responses of the chicken pineal gland and its effects on melatonin and Per2, Bmal1 and E4bp4 expression in 19-day old embryos and hatchlings during the dark phase, subjective light phase and in constant darkness. Expression of Per2 and E4bp4 were rhythmic under light:dark conditions, but the rhythms of E4bp4 and Bmal1 mRNA did not persist in constant darkness in 19-day old embryos. Per2 mRNA expression persisted in constant darkness, but with a reduced amplitude. Per2 expression was inducible by light only during the subjective day. Melatonin release was inhibited by light only at end of the dark phase and during the subjective light phase in embryos. Our data demonstrate that the embryonic avian pineal pacemaker is light sensitive and can generate rhythmic output, however the effects of light were diminished in chick embryos in compared to hatchlings.     

IFN-treated neuroblastoma cell lines remain resistant to T cell-mediated allo-killing, and susceptible to non-MHC-restricted cytotoxicity

Neuroblastoma cell lines can have very low MHC Ag expression. The cell lines are insensitive to allo-killing by primed CTL, but are sensitive to non-MHC-restricted cytotoxicity. IFN-gamma increased class I expression, but the cells remained insensitive to CTL. Susceptibility to nonrestricted effectors was preserved. Class I+ glioma cell lines behaved similarly. The CTL resistance was localized to the recognition phase. Neuroblastoma lines did not form conjugates with primed T cells, but were lysed if they were coupled to the effectors via lectins. The levels of class I expression, and resistance to CTL, were constant over a range of IFN doses. HLA-A,B,C structure and distribution were studied more intensively on one cell line, CHP-100. HLA-A2 and -A3 were present on greater than or equal to 99% of the cells, in a unimodal distribution. After IFN treatment, the levels were similar to B cell controls. In two-dimensional gel electrophoresis, the molecules co-migrated with those of B cell controls. The defect may thus be in accessory proteins that are necessary for T cell recognition or binding, rather than in the structure or distribution of the HLA-A,B,C proteins.