Oxygen-glucose deprivation in organotypic hippocampal cultures leads to cytoskeleton rearrangement and immune activation : link to the potential pathomechanism of ischaemic stroke

Ischaemic stroke is characterized by a sudden loss of blood circulation to an area of the brain, resulting in a corresponding loss of neurologic function. As a result of this process, neurons in the ischaemic core are deprived of oxygen and trophic substances and are consequently destroyed. Tissue damage in brain ischaemia results from a complex pathophysiological cascade comprising various distinct pathological events. Ischaemia leads to brain damage by stimulating many processes, such as excitotoxicity, oxidative stress, inflammation, acidotoxicity, and apoptosis. Nevertheless, less attention has been given to biophysical factors, including the organization of the cytoskeleton and the mechanical properties of cells. Therefore, in the present study, we sought to evaluate whether the oxygen-glucose deprivation (OGD) procedure, which is a commonly accepted experimental model of ischaemia, could affect cytoskeleton organization and the paracrine immune response. The abovementioned aspects were examined ex vivo in organotypic hippocampal cultures (OHCs) subjected to the OGD procedure. We measured cell death/viability, nitric oxide (NO) release, and hypoxia-inducible factor $1\alpha$ (HIF-$1\alpha$) levels. Next, the impact of the OGD procedure on cytoskeletal organization was evaluated using combined confocal fluorescence microscopy (CFM) and atomic force microscopy (AFM). Concurrently, to find whether there is a correlation between biophysical properties and the immune response, we examined the impact of OGD on the levels of crucial ischaemia cytokines (IL-$1\beta$, IL-6, IL-18, TNF-$\alpha$, IL-10, IL-4) and chemokines (CCL3, CCL5, CXCL10) in OHCs and calculated Pearsons’ and Spearman’s rank correlation coefficients. The results of the current study demonstrated that the OGD procedure intensified cell death and nitric oxide release and led to the potentiation of HIF-$1\beta$ release in OHCs. Moreover, we presented significant disturbances in the organization of the cytoskeleton (actin fibers, microtubular network) and cytoskeleton-associated protein 2 (MAP-2), which is a neuronal marker. Simultaneously, our study provided new evidence that the OGD procedure leads to the stiffening of OHCs and a malfunction in immune homeostasis. A negative linear correlation between tissue stiffness and branched IBA1 positive cells after the OGD procedure suggests the pro-inflammatory polarization of microglia. Moreover, the negative correlation of pro- and positive anti-inflammatory factors with actin fibers density indicates an opposing effect of the immune mediators on the rearrangement of cytoskeleton induced by OGD procedure in OHCs. Our study constitutes a basis for further research and provides a rationale for integrating biomechanical and biochemical methods in studying the pathomechanism of stroke-related brain damage. Furthermore, presented data pointed out the interesting direction of proof-of-concept studies, in which follow-up may establish new targets for brain ischemia therapy

The effect of intensive and extensive production systems on carcass quality in New Zealand White rabbits

[EN] Forty New Zealand White rabbits weaned at 30 days were divided into 2 groups and reared under intensive or extensive production system till slaughter age (90 days of age). In the extensive production system, rabbits were housed in free-standing cages on straw litter and fed farm-made feed ad libitum. Control rabbits were raised intensively in wire mesh slatted floor cages, indoors and on a commercial pellet ad libitum. Hot carcass weight was 16,6% lower (P0.05). The higher carcass weight of the control rabbits led to heavier primal cuts, including head (P0.05) and the fore part, intermediate part and hind part of the carcass (P0.01). However, expressed as % of carcass weight, a significantly higher ratio was only found for the head (P0.01) and edible offal (P0.05) in intensively produced rabbits. The production systems investigated had no significant (P>0.05) effect on the chemical composition, physicochemical properties and organoleptic characteristics of meat from New Zealand White rabbits.Daszkiewicz, T.; Gugolek, A.; Janiszewski, P.; Kubiak, D.; Czoik, M. (2012). The effect of intensive and extensive production systems on carcass quality in New Zealand White rabbits. World Rabbit Science. 20(1):25-33. doi:10.4995/wrs.2012.945SWORD253320

Mantle-crust differentiation of chalcophile elements in the oceanic lithosphere

The chalcophile elements, as associated with sulfides, are believed mainly from the study of ophiolites to be generally enriched in the upper mantle, but depleted by magmatic processes in the lower and upper ocean crust. However, studies of some orogenic lherzolites suggest a copper depletion of peridotites in relation to the primitive mantle, suggesting that a portion of the sulfides is melted during decompression and incorporated into the ascending magmas. The rarity of abyssal peridotites and the high degree of their alteration have not allowed these results to be verified in situ in the oceans. Here, we present the first complete study of chalcophile elements based on a suite of rocks from an oceanic core complex (OCC), the Kane Megamullion at 22°30’N at the MidAtlantic Ridge. OCCs provide large exposures of mantle and lower crustal rocks on the seafloor on detachment fault footwalls at slow and ultraslow spreading ridges. The Kane Megamullion is one of the best sampled OCCs in the world, with 1342 rocks from 28 dredge sites and 14 dives. We have made XRF, TDMS and INAA analyses of 129 representative peridotites, gabbroic rocks, diabases and basalts. Our results suggest a depletion of some peridotites in relation to the primitive mantle (28 ppm Cu). Dunites, troctolites and olivine gabbros are relatively enriched in chalcophile elements. The amount of sulfides decreases gradually with progressive differentiation, reaching a minimum in gabbronorites and diabases. The highest bulk abundance of chalcophile elements in our sample suite was observed in dunites (up to ~ 300 ppm Cu in several samples) and a contact zone between residual peridotite and a mafic vein (294 ppm Cu). Plagioclasebearing harzburgites, generally formed by latestage melt impregnation in the mantle, are typically more enriched in Cu than unimpregnated residual peridotites. For these reasons, our initial results indicate sulfide melting during mantle melting, and their local precipitation in the mantle lithosphere due to late-stage melt impregnation

Cytostatic factor inactivation is induced by a calcium-dependent mechanism present until the second cell cycle in fertilized but not in parthenogenetically activated mouse eggs

Cytostatic factor (CSF) is an activity responsible for the metaphase II arrest in vertebrate oocytes. This activity maintains a high level of maturation promoting factor (MPF) in the oocyte and both activities are destroyed after fertilization or parthenogenetic activation. To study some of the characteristics of the mechanism involved in MPF and CSF destruction, we constructed hybrid cells between metaphase II arrested oocytes and early embryos obtained after fertilization or artificial activation. We found that the behavior of hybrid cells differed depending upon the type of oocyte activation. Initially, the reaction of both types of hybrid cells was similar, the nuclear envelope broke down and chromatin condensation was induced. However, while metaphase II oocytes fused with parthenogenetic eggs remained arrested in M-phase, the oocytes fused with fertilized eggs underwent activation and passed into interphase. This ability of fertilized eggs to induce oocyte activation was still present at the beginning, but not at the end of the second embryonic cell cycle. Oocyte activation induced by fusion with a fertilized egg could be prevented when calcium was chelated by BAPTA. Thus, element(s) of the mechanism involved in calcium release triggered by a sperm component at fertilization remain(s) active until the second cell cycle and is (are) inactivated before the end of the 2-cell stage

Cartographic and remote-sensing data as a source of landscape ecological information on the Poznań metropolitan area

This paper characterises the system of organisation and access to spatial information in Poland based on the example of the Poznań metropolitan area. It describes the available cartographic resources, both topographic (general) and thematic. Particular attention was paid to remote sensing, being the source of the most current and nongeneralised information on geographic space. As a result of the implementation of the INSPIRE directive, activities aimed at integrating and sharing spatial data in a digital form were intensified. A practical outcome of the above is presented in the article published at Geoportal (www.geoportal.gov.pl). The final part of this paper shows the current applications and requirements concerning the use of spatial data in the modern management of a metropolitan area