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Utilization of biocompatible hydrogels based on 2-hydroxyethylmethacrylate to bridge the spinal cord lesion
Lesný, Petr ; Syková, Eva (advisor) ; Rokyta, Richard (referee) ; Hampl, Aleš (referee)
Utilization of biocompatible hydrogels based on 2-hydroxyethylmethacrylate to bridge the spinal cord lesion MUDr. Petr Lesný Biocompatible hydrogels based on copolymers of 2-hydroxyethylmethacrylate are suitable for implantation into a central nervous tissue lesion. Our prepared hydrogels were macroporous with predominantly communicating pores, and their mechanical properties were similar to those of spinal cord tissue. After we confirmed their biocompatibility by the growth of mesenchymal stem cells and determined the hydrogel diffusion properties, we implanted the prepared hydrogels into acute spinal cord injury in laboratory rats and studied the process of spinal cord tissue regeneration within the implants. When the hydrogels were implanted in subacute phase of spinal cord injury, we observed favorable impact on the spinal cord tissue regeneration and reduction of pseudocyst formation. Using histological and immunohistochemical methods, we observed the ingrowth of central nervous tissue elements (connective tissue, vessels, neurofilaments, Schwann cells, astrocyte processes) into the hydrogels implanted into the spinal cord hemisections. We have found that copolymerization with a positively charged ammonium salt increases the adhesion of the cells to the hydrogels in vitro and the ingrowth of...
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Nanotechnology and biomaterials for application in cell therapy of spinal cord injury
Vaněček, Václav ; Syková, Eva (advisor) ; Smetana, Karel (referee) ; Haninec, Pavel (referee)
New approaches for the treatment of SCI use advances in the fields of nanotechnology, biomaterial science and cell therapy. The results presented in this thesis showed that superparamagnetic iron oxide nanoparticles coated with a stable dopamine-hyaluronane associate can be used for the safe and effective labeling of MSC. Cell labeling efficiency, viability and the relaxivity of the tested particles were significantly better than those obtained with the commercial particles Endorem®. The DPA-HA coated nanoparticles can be used for the noninvasive monitoring of cell therapy using MRI. Furthermore, we showed that SPION can be used for the targeted delivery of MSC to the site of a spinal cord lesion. The labeled cells can be concentrated in the lesion area by means of a magnetic implant. The process of cell targeting depends on the physical characteristics of the magnetic implant as well as on the biological features of the cells and nanoparticles, as we described with a proposed mathematical model. It is possible to modify the properties of the magnetic system, e.g. by changing the shape or size of the magnet, thus tuning the magnetic force distribution and the gradient of the magnetic field necessary for effective cell targeting. A promising therapeutic strategy for the treatment of spinal cord injury is the...
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Lymphocyte subpopulations, cytokine production and stem cells transplantation in multiple sclerosis patients
Krasulová, Eva ; Kubala Havrdová, Eva (advisor) ; Ehler, Edvard (referee) ; Syková, Eva (referee)
Multiple sclerosis (MS) represents a demyelinating disease of the central nervous system with known autoimmune etiology. Currently new diagnostic criteria are used allowing us to diagnose MS early after first relapse of clinical symptoms. Several drugs are available to reduce disease activity and postpone later MS stages with irreversible disability. Prognosis of an individual patient and accurate treatment is however defined only imperfectly based on our clinical experience and brain magnetic resonance imaging. Specific prognostic markers are missing. Aims: 1. To identify suitable prognostic immunological marker from peripheral blood of MS patients in different disease stages and under different treatment regimens; 2. To describe group of MS patients treated with autologous stem cells transplantation (ASCT) or allogeneic stem cells transplantation (alloSCT) with respect to efficacy, adverse events and accurate patient selection. Patients and methods: In the first part of the study we involved 33 patients with clinically isolated syndrome, 17 MS patients treated with natalizumab and 14 patients with aggressive MS treated with ASCT. Disability measured by Expanded Disability Status Scale (EDSS) as well as relapse rate were evaluated before treatment (baseline) and after 3, 6, 12 and 24 months after...
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Astrocytic changes in a mouse model of Alzheimer's disease
Kulijewicz-Nawrot, Magdalena ; Syková, Eva (advisor) ; Rokyta, Richard (referee) ; Zach, Petr (referee)
1. SUMMARY: In this thesis we reported astrocytic atrophy characterized by a reduction in the surface area and volume of GFAP-positive glial cells in the prefrontal cortex of 3xTg-AD mice - an important morphological alteration starting far before any well known histopathological hallmark of AD. This change is present in parallel with homeostatic failure suggested by the decreased expression of GS. Those alterations can have drastic effects on brain connectivity and the biochemistry of the main neurotransmitters within the brain, such as glutamate and GABA. GFAP is implicated in a variety of processes, such as cell migration and proliferation, neurite outgrowth, astrocytic glutamate transporter expression (GLAST and GLT-1) and synaptic plasticity, so that every change can shift the astrocytes' role from physiology to pathology. In the case of affected GFAP-IR astrocytes, the withdrawal of processes from neurons and synapses can lead to a severe transmission crush, due to the uncontrolled spillover of the neurotransmitter from the synaptic cleft, inadequate metabolic support and the lack of a physiological barrier between the affected synapse and other synapses in its close vicinity. This will directly disturb the reciprocal connections between the affected brain regions, inluding the important structures...
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Neuroregeneration after spinal cord injury and in amyotrophic lateral sclerosis -possibilities for stem cell therapy
Forostyak, Serhiy ; Syková, Eva (advisor) ; Rokyta, Richard (referee) ; Mazanec, Radim (referee)
Adipose-derived MSC could be used as an alternative for bone marrow MSC in the treatment of acute SCI. We used the intraspinal grafting of rat adipose-derived naïve and predifferentiated MSC to improve motor function after a balloon-induced compression lesion of the rat spinal cord. Grafted cells survived for seven weeks after transplantation, improved motor activity and integrated into the host tissue. They expressed the oligodenrocyte precursor marker NG2 and, occasionally, the astrocytic marker GFAP, but did not transdifferentiate into a neuronal phenotype. Bone marrow MSC may change the disease course and extend lifespan in a rat model of ALS. Combined intraspinal and intravenous transplantation of rat BMSC was performed in symptomatic rats overexpressing the SOD1 G93A gene. Cell-treated animals lived longer compared with sham-treated rats and displayed significantly improved motor activity and grip strength. Rat BMSC survived until the end stage of the disease and were migrating along the white matter of the spinal cord. Grafted cells increased the number of host cells displaying positive staining for neurofilaments and significantly increased the number and also the size of the remaining spinal motoneurons 10-11 weeks after delivery, compared with vehicle-injection. The defragmentation of DNA, a sign...
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Extracellular space diffusion parameters and metabolism in the rat somatosrensory cortex during recovery from trabsient global ischemia and hypoxia
Zoremba, Norbert ; Syková, Eva (advisor) ; Mareš, Pavel (referee) ; Rokyta, Richard (referee)
Content Abstract .................................................................. ..... ...... ............................ .... 2 Introduction ............................................ ........................................ .................. 4 Aims .................. ................. ................................ ....... ..... . ............ .......... 6 Methods ............................................... ......................................................... ... 7 Results ................ ............................................................................ .................. 9 Discussion .. ... ............... .. ......... .. .......................... ............................. ... ............. 13 References ....... ................................................................ ....................... ........ 20 List of Publications ............. .... .. ............... .. ... .. .......... .. ... ............................... .... 22 Abstract The extracellular space (ECS) of the brain represents the microenvironment of nerve cells and enables the diffusion of neuroactive substances among neurons, axons and glia. Changes in the ECS diffusion parameters during ischemia are well known, but information about changes in ECS diffusion and energy-related metabolite...
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Diffusion parameters of brain tissue during ischemia and during status epilepticus
Šlais, Karel ; Syková, Eva (advisor) ; Otáhal, Jakub (referee) ; Rokyta, Richard (referee) ; Dezortová, Monika (referee)
Difusion of neuroactive substances in the extracellular space (ECS) is constrained by two factors: extracellular space volume and geometry. We have shown changes of diffusion parameters and extracellular concentrations of energetic metabolites and glutamate in two pathological states accompanied by significant ECS volume changes - in combined hypoxia/ischemia and in status epilepticus. In the model of hypoxia/ischemia, we have shown time courses of diffusion parameters, concentrations of glucose, lactate, lactate/pyruvate ratio and glutamate during hypoxic/ischemic insult and after reperfusion. The time course of glutamate extracellular concencetration in transient hypoxia/ischemia correlated well with time course of changes in diffusion parameters. The decrease in the ECS volume fraction can therefore contribute to an increased accumulation of toxic metabolites, which may aggravate functional deficits and lead to damage of the central nervous system. In the model of pilocarpine-induced status epilepticus our results show changes in the extracellular space diffusion parameters, K+, energy-related metabolites and glutamate during the initiation and first hours of the propagation. Our results also show that the first minutes after a pilocarpine injection are followed by an increase in extracellular K+ and a...
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Experimental bridging of spinal cord injury with hydrogels
Hejčl, Aleš ; Syková, Eva (advisor) ; Rokyta, Richard (referee) ; Filip, Stanislav (referee)
Hydrogels are biomaterials used in the treatment of experimental spinal cord injury (SCI). In a model of acute SCI, we implanted hydrogels based on 2-hydroxyethylmethacrylate (HEMA) and hydroxypropylmethacryla-mide (HPMA). One month after implantation the hydrogels bridged the cavity, adhered well to the spinal cord and created permissive environment, infiltrated with blood vessels, axons and Schwann cells. Physical modifications (e.g. surface charge) of hydrogels may improve bridging of acute SCI. We implanted hydrogels based on HEMA with a surface charge in spinal cord hemisection and compared with a hydrogel without charge. Hydrogels with surface charge improved connective tissue adhesion and growth of axons compared to a hydrogel without charge. Biodegradable hydrogels may bridge a lesion followed by complete re-sorption. In a model of acute SCI we implanted hydrogels based on the copolymer of HPMA and etoxyethylmethacrylate (EOMA) degraded from the periphery, which was substituted with new tissue after 1 month, to the center, comprising amorphous residuals of the hydrogel. Delayed hydrogel implantation may improve bridging of spinal cord le-sion. We implanted hydrogels based on HEMA acutely or in a delayed fashion (after 7 days) in spinal cord transection. Delayed implantation re-duced the volume of...
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Neurogenic pulmonary edema in rats with spinal cord injury
Šedý, Jiří ; Syková, Eva (advisor) ; Herget, Jan (referee) ; Rokyta, Richard (referee)
N urogenic puhnonary edema (NPE) is an acu te life-threatening complication of the c ntral nervous system (CNS) injury. Anesthetics can either promote or inhibit the NPE development. We examined the role of different concentrations of isoflurane anesthesia (1.5 - 3%) on the developmen t of NPE in rats with balloon compressed spinal cord. The development of NPE was examined in vivo and on histological sections of lung tissue. Neurological recovery in animals anesthetized with 1.5% or 3% isoflurane was monitored using BBB and pian tar tests for 7 weeks post-injury. The grade of the spinal gray and white matter sparing was evaluated using morphornetry. The r le of gradually developed spinal cord lesíon and spínal cord transection in the developmen t of NPE were evaluated also. NPE developed in all animals anesthetized with 1.5-2% isofluran . Almost 42% of animals died due to massive pulmonary bleeding and suffocation; X-ray imaging, pulmonary index and histological sections showed massive NPE. More than 71 % of animals anesthetized with 2.5-3% i oflu rane had no signs of NPE. Blood pressure rose more rapidly in animals from 1.5% group than in 3% group; this hypertensive reaction was caused by the sympathetic hyperactivi ty. Animals from 3% group recovered their motor and sensory func tions more rapidly than...
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