19 research outputs found

    Characterisation of physico-mechanical properties and degradation potential of calcium alginate beads for use in embolisation

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    High molecular weight alginate beads with 59% mannuronic acid content or 68% guluronic acid were prepared using a droplet generator and crosslinked in calcium chloride. The alginate beads were compared to current embolisation microspheres for compressibility and monitored over 12 weeks for size and weight change at 37°C in low volumes of ringers solutions. A sheep uterine model was used to analyse bead degradation and inflammatory response over 12 weeks. Both the in vitro and in vivo data show good delivery, with a compressibility similar to current embolic beads. In vitro, swelling was noted almost immediately and after 12 weeks the first signs of degradation were noted. No difference was noted in vivo. This study has shown that high molecular weight alginate gel beads were well tolerated by the body, but beads associated with induced thrombi were susceptible to inflammatory cell infiltration. The beads were shown to be easy to handle and were still observable after 3 months in vivo. The beads were robust enough to be delivered through a 2.7 Fr microcatheter. This study has demonstrated that high molecular weight, high purity alginate bead can be considered as semi-permanent embolisation beads, with the potential to bioresorb over time

    Dermacentor reticulatus: a vector on the rise

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    Dermacentor reticulatus is a hard tick species with extraordinary biological features. It has a high reproduction rate, a rapid developmental cycle, and is also able to overcome years of unfavourable conditions. Dermacentor reticulatus can survive under water for several months and is cold-hardy even compared to other tick species. It has a wide host range: over 60 different wild and domesticated hosts are known for the three active developmental stages. Its high adaptiveness gives an edge to this tick species as shown by new data on the emergence and establishment of D. reticulatus populations throughout Europe. The tick has been the research focus of a growing number of scientists, physicians and veterinarians. Within the Web of Science database, more than a fifth of the over 700 items published on this species between 1897 and 2015 appeared in the last three years (2013–2015). Here we attempt to synthesize current knowledge on the systematics, ecology, geographical distribution and recent spread of the species and to highlight the great spectrum of possible veterinary and public health threats it poses. Canine babesiosis caused by Babesia canis is a severe leading canine vector-borne disease in many endemic areas. Although less frequently than Ixodes ricinus, D. reticulatus adults bite humans and transmit several Rickettsia spp., Omsk haemorrhagic fever virus or Tick-borne encephalitis virus. We have not solely collected and reviewed the latest and fundamental scientific papers available in primary databases but also widened our scope to books, theses, conference papers and specialists colleagues’ experience where needed. Besides the dominant literature available in English, we also tried to access scientific literature in German, Russian and eastern European languages as well. We hope to inspire future research projects that are necessary to understand the basic life-cycle and ecology of this vector in order to understand and prevent disease threats. We conclude that although great strides have been made in our knowledge of the eco-epidemiology of this species, several gaps still need to be filled with basic research, targeting possible reservoir and vector roles and the key factors resulting in the observed geographical spread of D. reticulatus. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-016-1599-x) contains supplementary material, which is available to authorized users

    Expansion of human mesenchymal stem cells in a fixed-bed bioreactor system based on non-porous glass carrier – Part B: Modeling and scale-up of the system

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    Human mesenchymal stem cells (hMSC) are a promising cell source for the manufacturing of cell therapeutic or tissue engineered implants. In part A of this publication a fixed-bed bioreactor system based on non-porous borosilicate glass spheres and procedures for the automated expansion of hMSC with high yield and vitality has been introduced. Part B of this study deals with the modeling of the process in order to transfer the bioreactors system from the laboratory to the production scale. Relevant model parameters have been obtained by fitting them to the experimental data of hMSC-TERT cultivations in scales up to 300 cm3. Scale-up calculations were carried out exemplarily for a target cell number of twenty billion cells

    Failure of Intravenous or Intracardiac Delivery of Mesenchymal Stromal Cells to Improve Outcomes after Focal Traumatic Brain Injury in the Female Rat

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    Mesenchymal stromal cells secrete a variety of anti-inflammatory factors and may provide a regenerative medicine option for the treatment of traumatic brain injury. The present study investigates the efficacy of multiple intravenous or intracardiac administrations of rat mesenchymal stromal cells or human mesenchymal stromal cells in female rats after controlled cortical impact by in vivo MRI, neurobehavior, and histopathology evaluation. Neither intravenous nor intracardiac administration of mesenchymal stromal cells derived from either rats or humans improved MRI measures of lesion volume or neurobehavioral outcome compared to saline treatment. Few mesenchymal stromal cells (<0.0005% of injected dose) were found within 3 days of last dosage at the site of injury after either delivery route, with no mesenchymal stromal cells being detectable in brain at 30 or 56 days post-injury. These findings suggest that non-autologous mesenchymal stromal cells therapy via intravenous or intracardiac administration is not a promising treatment after focal contusion traumatic brain injury in this female rodent model
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