Contrast enhanced X-ray computed tomography imaging of amyloid plaques in Alzheimer disease rat model on lab based micro CT system

Amyloid plaques are small (similar to 50 mu m), highly-dense aggregates of amyloid beta (A beta) protein in brain tissue, supposed to play a key role in pathogenesis of Alzheimer's disease (AD). Plaques' in vivo detection, spatial distribution and quantitative characterization could be an essential marker in diagnostics and evaluation of AD progress. However, current imaging methods in clinics possess substantial limits in sensitivity towards A beta plaques to play a considerable role in AD screening. Contrast enhanced X-ray micro computed tomography (micro CT) is an emerging highly sensitive imaging technique capable of high resolution visualization of rodent brain. In this study we show the absorption based contrast enhanced X-ray micro CT imaging is viable method for detection and 3D analysis of A beta plaques in transgenic rodent models of Alzheimer's disease. Using iodine contrasted brain tissue isolated from the Tg-F344-AD rat model we show the micro CT imaging is capable of precise imaging of A beta plaques, making possible to further analyze various aspects of their 3D spatial distribution and other properties

Nerve-associated Schwann cell precursors contribute extracutaneous melanocytes to the heart, inner ear, supraorbital locations and brain meninges

Melanocytes are pigmented cells residing mostly in the skin and hair follicles of vertebrates, where they contribute to colouration and protection against UV-B radiation. However, the spectrum of their functions reaches far beyond that. For instance, these pigment-producing cells are found inside the inner ear, where they contribute to the hearing function, and in the heart, where they are involved in the electrical conductivity and support the stiffness of cardiac valves. The embryonic origin of such extracutaneous melanocytes is not clear. We took advantage of lineage-tracing experiments combined with 3D visualizations and gene knockout strategies to address this long-standing question. We revealed that Schwann cell precursors are recruited from the local innervation during embryonic development and give rise to extracutaneous melanocytes in the heart, brain meninges, inner ear, and other locations. In embryos with a knockout of the EdnrB receptor, a condition imitating Waardenburg syndrome, we observed only nerve-associated melanoblasts, which failed to detach from the nerves and to enter the inner ear. Finally, we looked into the evolutionary aspects of extracutaneous melanocytes and found that pigment cells are associated mainly with nerves and blood vessels in amphibians and fish. This new knowledge of the nerve-dependent origin of extracutaneous pigment cells might be directly relevant to the formation of extracutaneous melanoma in humans

High-contrast differentiation resolution 3D imaging of rodent brain by X-ray computed microtomography

The biomedically focused brain research is largely performed on laboratory mice considering a high homology between the human and mouse genomes. A brain has an intricate and highly complex geometrical structure that is hard to display and analyse using only 2D methods. Applying some fast and efficient methods of brain visualization in 3D will be crucial for the neurobiology in the future. A post-mortem analysis of experimental animals' brains usually involves techniques such as magnetic resonance and computed tomography. These techniques are employed to visualize abnormalities in the brains' morphology or reparation processes. The X-ray computed microtomography (micro CT) plays an important role in the 3D imaging of internal structures of a large variety of soft and hard tissues. This non-destructive technique is applied in biological studies because the lab-based CT devices enable to obtain a several-micrometer resolution. However, this technique is always used along with some visualization methods, which are based on the tissue staining and thus differentiate soft tissues in biological samples. Here, a modified chemical contrasting protocol of tissues for a micro CT usage is introduced as the best tool for ex vivo 3D imaging of a post-mortem mouse brain. This way, the micro CT provides a high spatial resolution of the brain microscopic anatomy together with a high tissue differentiation contrast enabling to identify more anatomical details in the brain. As the micro CT allows a consequent reconstruction of the brain structures into a coherent 3D model, some small morphological changes can be given into context of their mutual spatial relationships

History of the Archives of the Czech Television with Focus on Specific Types of Archival Sources

Obsahem bakalářské práce jsou celkové dějiny Archivu České televize s důrazem na praktickou správu materiálů v současnosti. Práce se především zaměřuje na archivaci a ukládání specifických druhů archiválií po vzoru archivní legislativy. Pro Českou televizi jsou specifické druhy archiválií audiovizuální materiály uložené v oddělení Filmotéky, Videotéky a Archivu a dokumentace zpravodajství. V první kapitole je stručné nastínění historie České televize, neboť historické události přímo ovlivňovaly i správu archivu. Druhá kapitola se přímo zaměřuje na historický vývoj archivu v souvislosti s fondem audiovizuálních materiálů. Třetí kapitola popisuje nejnovější dějiny a současnou správu materiálů v jednotlivých odděleních.Content of this thesis is the overall history of the Archive of Czech Television, with emphasis on the current practical management of materials. The work is mainly focused on specific types of archrivals modeled according the archival legislation. For Czech Television are special kinds of archrivals audiovisual materials stored in the department of the Film archives, the Video archives and the Archives of documentation news. The first chapter is a brief outline of the history of Czech television, because of the historical events, which directly influenced the management of archives. The second chapter is directly focused on the historical evolution of archives relating to the Fund of audiovisual materials. The third chapter describes the recent history and the current management of materials in various departments.Fakulta filozofická1. Představení práce. 2. Posudek vedoucího práce a oponentky. 3. Diskuse: formální stránka prác

Structure and properties of AB21, a novel Agaricus bisporus protein with structural relation to bacterial pore-forming toxins

We report the characterization of the dimeric protein AB21 from Agaricus bisporus, one of the most commonly and widely consumed mushrooms in the world. The protein shares no significant sequence similarity with any protein of known function, and it is the first characterized member of its protein family. The coding sequence of the ab21 gene was determined and the protein was expressed in E. coli in a recombinant form. We demonstrated a high thermal and pH stability of AB21 and proved the weak affinity of the protein to divalent ions of some transition metals (nickel, zinc, cadmium, and cobalt). The reported crystallographic structure exhibits an interesting rod‐like helical bundle fold with structural similarity to bacterial toxins of the ClyA superfamily. By immunostaining, we demonstrated an abundance of AB21 in the fruiting bodies of A. bisporus