Our previous experiments revealed that water intoxication and osmotic BBB disruption in the rat allow penetration of high- molecular substances into the brain and that resulting changes in the internal environment of th e CNS lead to pathological development, such as the loss of integrity of myelin. The aim of the present study was to determine whether the previously described phenomena are associated with increased water content in the brain. To answer the question following methods were used: a) water intoxication : intraperitoneal administration of distilled water, b) osmotic BBB disruption: application of mannitol (20 %) selectively into the internal carotid artery, c) brain wet weight was measured after decapitation, and subsequently (after six days in thermostat set at 86 °C) the dry weight were estimated d) in animals with 20 % and 30 % hyperhydration the degree of myelin deterioration was estimated e) animal locomotor activity was tested by continuous behavior tracking and analysis. Brai n water content after water intoxication and following the administration of mannitol was higher than in the control group. Different degrees of hyperhydration led to different levels of brain water content and to different degrees of myelin impairment. Hyperhydration corresponding to 20 % of the body weight brought about lower locomotor activity. Increased water content in the brain after the BBB osmotic disruption is surprising because this method is frequently used in the clinical practice., P. Kozler, V. Riljak, J. Pokorný., and Obsahuje bibliografii a bibliografické odkazy
Bothriocephalidean tapeworms parasitic in the blackfish, Centrolophus niger (Gmelin) (Perciformes: Centrolophidae), are redescribed on the basis of the evaluation of freshly collected specimens and museum material. This evaluation enabled us to supplement species diagnoses by new morphological characters of potential use for phylogenetic analyses, including the data from scanning electron microscopical observations, and to provide a key to identification of the following four species occurring in this fish: Amphicotyle heteropleura (Diesing, 1850); Milanella familiaris Kuchta et Scholz, 2008 (both Triaenophoridae); Bothriocotyle solinosomum Ariola, 1900; and Echinophallus wageneri (Monticelli, 1890) (both Echinophallidae). Large spiniform microtriches were observed on the surface of the posterodorsal margin of segments of B. solinosomum, E. wageneri and M. familiaris. The invalidity of Atelemerus Guiart, 1935, first proposed by Bray et al. (1994), is supported by the present data and its type species, A. acanthodes Guiart, 1935, is newly synonymised with E. wageneri.
In this paper, the algorithm for the discretization of 3D domains into tetrahedral boundary conforming meshes is presented. The algorithm is based on the Delaunay triangulation with special point ordering. The conformity of the resulting mesh with the initial triangulation of the domain boundary is ensured a priori thus the boundary recovery postprocessing step is eliminated. The constrained Delaunay triangulation of the boundary points is obtained using modified Watson's point insertion algorithm. The actual appearance of boundary faces in the final triangulation is achieved by the form of an oriented graph, of the violation of the empty-sphere property of all boundary faces. The cycle dependencies (closed loops in the graph) are eliminated by using the nodal perturbations, by classification of some of the violations as safe and (as the last resort) by forming a new tetrahedron using the advancing front technique. Once all the cyclic dependencies are eliminated, the point insertion process controlled by the dependency graph is started and the constrained Delaunay triangulation of the boundary points is built. In the next phase, additional points are inserted in the interior of the domain, while preserving the boundary constraints, to make the elements of appropriate size with aspect ratio close to one. The resulting mesh is then subjected to optimization in terms of the combination of Laplacian smoothing and topological transformations, in order to remove the potential slivers and to improve the overall mesh quality. and Obsahuje seznam literatury