Norbert Cyran

Bio: Norbert Cyran is an academic researcher from University of Vienna. The author has contributed to research in topics: Idiosepius & Mucus. The author has an hindex of 9, co-authored 22 publications receiving 309 citations.

Histochemical characterization of the adhesive organ of three Idiosepius spp. species

Abstract: An adhesive organ is a prominent characteristic of the genus Idiosepius. Histological, histochemical and ultrastructural methods were applied to elucidate the nature of secretion of the epithelial cells of three Idiosepius species. The adhesive organs of Idiosepius biserialis and Idiosepius pygmaeus consist of five distinct cell types that can be distinguished morphologically and by the composition of their secretions. Histochemical analysis revealed that three cell types contain different sugar units and basic proteins, whereas the interstitial cells lacked secretory material. Acidic and sulfated substances were absent in Idiosepius secretions. The adhesive organ, but not the secretory material of the glandular cells, contained O-linked oligosaccharides. The histochemical analysis of the secretory products suggested that adhesion and release are not effected by a "duo-gland" adhesive system as in Euprymna scolopes. Idiosepius presumably uses a transitory adhesion, perhaps induced by secretion of a highly viscous gel. Release might be caused by contraction of the mantle musculature and/or chemical release mechanisms such as dilutors or enzymes.

Nanoscale Tungsten-Microbial Interface of the Metal Immobilizing Thermoacidophilic Archaeon Metallosphaera sedula Cultivated With Tungsten Polyoxometalate

Abstract: Inorganic systems based upon polyoxometalate (POM) clusters provide an experimental approach to develop artificial life. These artificial symmetric anionic macromolecules with oxidometalate polyhedra as building blocks were shown to be well suited as inorganic frameworks for complex self-assembling and organizing systems with emergent properties. Analogously to mineral cells based on iron sulfides, POMs are considered as inorganic cells in facilitating prelife chemical processes and displaying "life-like" characteristics. However, the relevance of POMs to life-sustaining processes (e.g., microbial respiration) has not yet been addressed, while iron sulfides are very well known as ubiquitous mineral precursors and energy sources for chemolithotrophic metabolism. Metallosphaera sedula is an extreme metallophilic and thermoacidophilic archaeon, which flourishes in hot acid and respires by metal oxidation. In the present study we provide our observations on M. sedula cultivated on tungsten polyoxometalate (W-POM). The decomposition of W-POM macromolecular clusters and the appearance of low molecular weight W species (e.g., WO) in the presence of M. sedula have been detected by electrospray ionization mass spectrometry (ESI-MS) analysis. Here, we document the presence of metalloorganic assemblages at the interface between M. sedula and W-POM resolved down to the nanometer scale using scanning and transmission electron microscopy (SEM and TEM) coupled to electron energy loss spectroscopy (EELS). High-resolution TEM (HR-TEM) and selected-area electron diffraction (SAED) patterns indicated the deposition of redox heterogeneous tungsten species on the S-layer of M. sedula along with the accumulation of intracellular tungsten-bearing nanoparticles, i.e., clusters of tungsten atoms. These results reveal the effectiveness of the analytical spectroscopy coupled to the wet chemistry approach as a tool in the analysis of metal-microbial interactions and microbial cultivation on supramolecular self-assemblages based on inorganic metal clusters. We discuss the possible mechanism of W-POM decomposition by M. sedula in light of unique electrochemical properties of POMs. The findings presented herein highlight unique metallophilicity in hostile environments, extending our knowledge of the relevance of POMs to life-sustaining processes, understanding of the transition of POMs as inorganic prebiotic model to life-sustainable material precursors and revealing biogenic signatures obtained after the decomposition of an artificial inorganic compound, which previously was not associated with any living matter.

Unlike Bone, Cartilage Regeneration Remains Elusive

Abstract: Articular cartilage was predicted to be one of the first tissues to successfully be regenerated, but this proved incorrect In contrast, bone (but also vasculature and cardiac tissues) has seen numerous successful reparative approaches, despite consisting of multiple cell and tissue types and, thus, possessing more complex design requirements Here, we use bone-regeneration successes to highlight cartilage-regeneration challenges: such as selecting appropriate cell sources and scaffolds, creating biomechanically suitable tissues, and integrating to native tissue We also discuss technologies that can address the hurdles of engineering a tissue possessing mechanical properties that are unmatched in human-made materials and functioning in environments unfavorable to neotissue growth

Histochemistry, Theoretical and Applied.

Abstract: municable disease control to the newer responsibilities of the hazards of ionizing radiation and medical defense against atomic attack. The individual topics are adequately developed with emphasis, in the majority, on brevity of presentation rather than complete and exhaustive detail. References are listed after each chapter for the reader desiring more definitive information. \"Epidemiologic Methods and Inferences\" by Dr. Dienfeld and \"Official and Voluntary Health Agencies\" by Dr. Hilleboe are two chapters which offer especially well-organized, succinct, and effective discussions of their respective subjects. The editors state in their preface that they are presenting \". . a new way to look at preventive medicine for the medical students, general practitioners, specialists, and professional workers in official and voluntary health agencies.\" In the opinion of the reviewer, the authors have achieved their purpose by editing a book which is more an introductory text than a reference tome.

Tissue engineering of functional articular cartilage: the current status

Abstract: Osteoarthritis is a degenerative joint disease characterized by pain and disability. It involves all ages and 70% of people aged >65 have some degree of osteoarthritis. Natural cartilage repair is limited because chondrocyte density and metabolism are low and cartilage has no blood supply. The results of joint-preserving treatment protocols such as debridement, mosaicplasty, perichondrium transplantation and autologous chondrocyte implantation vary largely and the average long-term result is unsatisfactory. One reason for limited clinical success is that most treatments require new cartilage to be formed at the site of a defect. However, the mechanical conditions at such sites are unfavorable for repair of the original damaged cartilage. Therefore, it is unlikely that healthy cartilage would form at these locations. The most promising method to circumvent this problem is to engineer mechanically stable cartilage ex vivo and to implant that into the damaged tissue area. This review outlines the issues related to the composition and functionality of tissue-engineered cartilage. In particular, the focus will be on the parameters cell source, signaling molecules, scaffolds and mechanical stimulation. In addition, the current status of tissue engineering of cartilage will be discussed, with the focus on extracellular matrix content, structure and its functionality.