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Sirvi Autor "Aunapuu, Marina (advisor)" järgi

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  • Pisipilt
    Kirje
    Expression of BMP and Pax Proteins in the Central Nervous System of Human and Rat Embryos at Early Stages of Development
    (Eesti Maaülikool, 2017) Namm, Aimar; Arend, Andres (advisor); Aunapuu, Marina (advisor); Sinowatz, Fred (opponent)
    The roles of BMP and Pax in the embryonic development have been extensively studied in recent years and the formation of the neural tube is usually described as a self-evident process, but formation of nervous system in human embryos has actually not been examined in detail. In the present study 40 human embryos at Carnegie stages (CS) 10-20 were obtained, and the expression of BMP-2, BMP-4, Pax2, Pax6 and Pax7 proteins were examined in the developing brain. 22 rat embryos of CS 14, 18 and 20 were employed to compare the BMP-2, BMP-4 and Pax2 expression in the developing spinal cord of human and rat embryos throughout early stages of the nervous system development. To detect expression of proteins the method of immunohistochemistry was used. BMP-2 and BMP-4 are essential signalling molecules for the formation of the neural tube in human embryos as their expression was seen throughout all studied developmental stages 10-20. The expression of both proteins, BMP-2 and BMP-4, had a tendency to decline in the later stages of the development. In the developing CNS of rat embryos BMP-2 and BMP-4 have a similar spatial and temporal expression pattern compared to the corresponding stages of the human embryos. However, slight differences were noted as in the spinal cord of rat embryos BMP-2 and BMP-4 expression was weaker compared to human embryos. In the human embryos Pax2, Pax6 and Pax7 were identified as signalling molecules that are involved in the formation of the early spinal cord and brain. The expression of Pax2, Pax6 and Pax7 had a tendency to increase in the later stages of the development both in the spinal cord and the brain. Significantly weaker expression of the Pax proteins was observed at CS 10. The similar temporal expression pattern of Pax2 to human embryos was seen in the forming spinal cord of rat embryos, as the Pax2 expression was found to increase at the later stages of the development. Differently from human embryos, no clear regional differences in Pax2 expression in the developing spinal cord of the rat embryos were not seen. It can be said that in the human and rat embryos BMP-2, BMP-4, Pax2, Pax6 and Pax7 proteins are associated with the establishment of neuroepithelial cells within the developing neural tube and with the migration and the differentiation of specific neural cell populations. In particular, the studied signalling molecules play an essentially important role in the determining of the dorsal-ventral and rostral-caudal axis of the developing brain.
  • Pisipilt
    Kirje
    Rod-through-plate fixator in the treatment of long bone fractures of small animals
    (Eesti Maaülikool, 2015) Tralman, Garri; Andrianov, Vladimir (advisor); Aunapuu, Marina (advisor)
    The primary objective of present research was to compare the efficiency of a novel bone fixator for treatment of tibial fractures in sheep and to compare to bone plating and to describe the surgical technique used in experimental animals. Rod-through-plate fixator (RTP fixator) combines intramedullary and extramedullary osteosynthesis. It is composed of a pair of curved intramedullary rods, a connecting extramedullary plate, two cortical screws and two fixation screws. Connecting plate is relatively short and curved rods lengthen the intramedullary shoulder of the fixator up towards the metaphyses. Screws are connecting rods to the plates and the fixator to the bone. Experimental osteotomies were performed in the middle third of the left tibia in all animals. Animals were divided into two groups: in one group (four animals) rod-through-plate fixator was applied, and in the other group (three animals) bone plating was used. The duration of the experiments was 10 weeks during which fracture union was followed by radiography. The healing process was assessed by blood serum markers reflecting bone turnover and by histological and immunohistochemical investigations. More radiographic evidence of callus formation was seen in the RTP fixator group. No statistically significant differences in histological, immunohistochemical or serum biomarker values were noted between the experimental groups We conclude that RTP fixation is efficient for the treatment of experimental osteotomies of long bones in sheep. The fixator was used also in six clinical cases for the diaphyseal middle third fracture treatment in dogs.