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1

Uwagi do dyskusji statystyków polskich nad artykułem "Czy statystyk może dostarczyć dane wysokiej jakości?"

100%
Platek R., Sarndal C.-E.
Wiadomości Statystyczne
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2002
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tom 47
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nr 02
2

Czy statystyk może dostarczyć dane wysokiej jakości?

100%
Platek R., Sarndal C.-E.
Wiadomości Statystyczne
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2001
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tom 46
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nr 04
3

Jerzy Chorobski (1902-1986) - the founder of Polish neurosurgery

81%
Platek R., Czarkowska-Bauch J., Skup M.
Acta Neurobiologiae Experimentalis
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2009
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tom 69
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nr 3
Jerzy Choróbski, a distinguished neurosurgeon, who established Polish modern neurosurgery, graduated in medicine from the Jagiellonian University in 1926 and developed his career in European and American clinics. In 1920s he studied in Paris and mastered his talent among the elite European neurologists, neurosurgeons and psychiatrists of those days (Bidziński 2008). In 1930s, as a grantee of M. Ottman and Rockefeller Foundations, Choróbski specialized in neurosurgery under supervision of Prof. Penfi eld in Montreal. Many of his scientifi c relations outlasted the time of World War II and resulted in visits of leading neurosurgeons in Poland. Under diffi cult facility circumstances, on 6 November 1935 Choróbski opened a 15-bed Neurosurgery Ward at the Department of Neurological Diseases of the Warsaw University. He considered that date as the beginning of Polish modern neurosurgery. Choróbski broaden the spectrum of neurosurgeries being performed so far and many were conducted in Poland for the fi rst time. In addition to brain, cerebellar or spinal cord tumors, he developed surgical treatment of sympathetic system diseases, which couldn’t be cured pharmacologically at that time. Together with progress of diagnostic techniques, Choróbski introduced surgical treatment of epilepsy based on Penfi eld school approach and developed therapy of brain vascular diseases. This talented neurosurgeon established also surgical treatment of involuntary movements (Choróbski 1961, 1962).
4

Obłaskawione wirusy w służbie nauki i medycyny

81%
Ziemlinska E., Platek R., Skup M.
Kosmos
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2011
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tom 60
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nr 3-4
5

Visualization of large scale objects using confocal microscope leica TSC LSI

81%
Platek R., Korczynski J., Skup M.
Acta Neurobiologiae Experimentalis
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2011
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tom 71
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nr S
Conventional confocal microscopy is dedicated mainly to proceed with thin tissue sections and cells seeded on a cover slip. The Leica TCS LSI macro confocal is the first super zoom microscope that combines all benefits of traditional confocal microscopy with large scale imaging of anesthetized, alive objects as well as unfixed/fixed objects post mortem. In our experiments we have tested Leica TCS LSI for scanning of (1) murine brains and spinal cords in vivo, and dissected in toto immediately post mortem, and (2) fixed rat spinal cords. We used transgenic mice expressing green fluorescent protein (GFP) under PLP promoter, to visualize oligodendrocytes, and rats with spinal cords transduced with AAV vector coding for enhanced GFP under mCMV promoter, to visualize neurons and glia. Super zoom confocal microscopy let us observe general distribution of GFP-expressing cells in whole organs as well as to focus on single cells and fibers. We were able to discriminate well between main morphological features of these cells. In murine brains we could visualize myelinated axons and oligodendrocytes, whereas in rat spinal cords the extent of eGFP expressing cells and their fibers traversing along entire spinal cord could be traced. The labeled objects could be visualized from the regions lying within a range of 150 - 350 μm from the surface of the brain/spinal cord. The details on the procedures applied, benefits and limitations of the method will be presented.
6

Intraspinal injection of AAV5_eGFP or AAV5_L1: extent of transduction and influence on regrowth of CST axons in adult rats after spinal cord transection

81%
Platek R., Korczynski J., Czarkowska-Bauch J., Skup M.
Acta Neurobiologiae Experimentalis
|
2011
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tom 71
|
nr S
Among approaches targeting restoration of function after spinal cord injury a promising one is to use L1 cell adhesion molecule, known to promote axon outgrowth, fasciculation, guidance and myelination in regeneration. L1 is upregulated after injury, manifesting requirements of the impaired networks for successful repair. Previously, our strategy to overexpress L1 gene in the lesion site was found to support reinnervation of the lumbar spinal cord after thoracic spinal cord compression in mice. Here we verified whether L1 overexpression induced caudal to complete spinal transection, may still have an impact on rostral segments affecting a regrowth of corticospinal tract (CST). AAV5 vector encoding eGFP or L1 protein under mCMV promoter was injected bilaterally into spinal L1 segment 30min after spinal cord transection at Th10/11. To label CST, rats were injected with anterograde tracer DiI to sensorimotor cortex, 1 week after spinalization. Effectiveness of transduction with AAV5 vector was evaluated based on distribution of eGFP protein at 7, 14 and 35 days. To evaluate CST regrowth, distances between lesion rostral border and tips of regrowing/sprouting single CST axons as well as the majority of axons were measured. eGFP expression occured throughout entire dorsoventral axis, in spinal gray and white matter, already 7 days postlesion and maintained up to 35. eGFP (+) fibers were traversing all segments caudally to lesion, some closing near its border but none seen in the lesion. It indicated that L1 transgene may be long-term available within segments below transection. CST tracing in AAV5_L1 revealed that in 3 out of 5 rats majority of CST axons reached the lesion border, whereas in AAV5_eGFP group only 1 out of 6 rats showed similar contact. In conclusion, AAV5_L1 overexpressed in segments caudal to complete transection may affect cellular milieu in transection proximity which results in better CST regrowth. Support: S007/Polish-German/2007/01 grant.
7

AAV5-mediated overproduction of LUCAM down-regulates perineuronal nets encapsulating motoneurons and their phosphacan component after complete spinal cord transection in the rat

81%
Grycz K., Platek R., Czrkowska-Bauch J., Skup M.
Acta Neurobiologiae Experimentalis
|
2015
|
tom 75
|
nr Supl.
BACKGROUND AND AIMS: The motoneurons (MNs) of the spinal cord are surrounded by perineuronal nets (PNNs) that restrict plasticity, maintain synapses and compartmentalize the neuronal surface. One of the PNN components, inhibitory to axonal growth in the injured spinal cord, is phosphacan (Pho), a chondroitin sulfate proteoglycan which binds to cell surface adhesion molecules such as L1CAM. Because L1CAM overexpression was found to promote recovery of spinal networks after injury we hypothesized that the mechanism may be through providing signals to downregulate Pho and PNNs. To evaluate the expression of Pho and response of PNNs encapsulating MNs to the injury and L1CAM overexpression in a chronic phase (5 weeks) after complete spinal cord transection. METHODS: Two groups of spinal rats (transected at Th9–10), injected with AAV5 vector carrying L1CAM or EGFP reference transgene and intact group were compared at the transcript (RTPCR) and protein (Pho immunofluorescence) level. PNNs were visualized with Wisteria floribunda agglutinin (WFA). Image analysis was performed on the longitudinal sections from the L1–2 segments acquired in confocal microscope. When analyzing PNN and Pho thickness, the perimeter of the net was taken as the point at which the most intense staining around the MN ended. Next, to focus on area of nerve terminals abutting on MNs, staining intensity of both markers was quantified in a rim around MNs limited to 2.1 mm. RESULTS: Pho around MNs formed the inner rim of PNN, occupying <50% of PNN thickness. Spinalization led to up-regulation of pho mRNA (2-fold, P<0.05) in L1–2 segments, and increased Pho protein (3-fold, P<0.05) in a rim. AAV-L1 injection decreased Pho towards controls (P<0.05) and reduced PNN thickness (by 45%), not modifying lesion-upregulated pho mRNA. CONCLUSION: L1 overexpression in spinal rats may promote MN reinnervation reducing PNNs involving Pho down-regulation. Support: NCN grants: 2013/09/B/NZ4/03306, Preludium12/05/N/ NZ4/02241.
8

Altered activity of neural progenitors in the subventricular zone of the cyclin D2-deficient mice

71%
Platek R., Rogujski P., Mazuryk J., Kaczmarek L., Czupryn A.
Acta Neurobiologiae Experimentalis
|
2017
|
tom 77
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nr Suppl.1
9

The impact of training and neurotrophins on functional recovery after complete spinal cord transection: cellular and molecular mechanisms contributing to motor improvement

61%
Skup M., Ziemlinska E., Gajewska-Wozniak O., Platek R., Maciejewska A., Czarkowska-Bauch J.
Acta Neurobiologiae Experimentalis
|
2014
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tom 74
|
nr 2
Beneficial effects of locomotor training on the functional recovery after complete transection of the spinal cord indicate that in chronic spinal animals spontaneous recovery processes are enhanced and shaped by the training. The mechanisms of that use-dependent improvement are still not fully understood. This review tackles three aspects of this issue: (1) neurochemical attributes of functional improvement showing that concentrations of excitatory and inhibitory amino acids in the lumbar spinal segments, which were changed after transection, normalize after the training, or even raise beyond normal. As it does not translate to functional equilibrium between excitatory and inhibitory neurotransmission and may lead to hyperexcitability, the postsynaptic mechanisms which might be responsible for the hyperexcitability are discussed, including (i) dysfunction of K+-Cl- cotransporter KCC2, which controls the strength and robustness of inhibition, and (ii) altered function of 5-HT2 receptors, which may be targeted to restore KCC2 activity and intrinsic inhibition; (2) morphological changes of lumbar motoneurons and their inputs related to functional improvement of spinal animals, pointing to use-dependent diminution/ reversal of the atrophy of the dendritic tree of the hindlimb motoneurons and of their synaptic impoverishment, which in paraplegic animals differs depending on the degree of disuse of the muscles; (3) the role of neurotrophins in motor improvement of spinal animals showing, that increases in neurotrophins due to training or due to efficient viral vector-based transgene expression, that might be responsible for the enrichment of the dendritic tree, elongation of processes and influence neurotransmitter systems in the areas subjected to plastic modifications after injury, correlate with improvement of locomotor functions.
10

In vivo transduction of spinal cord cells in adult, spinalized rats, with adeno-associated viral vectors:long-term efficiency and specificity of AAV1/2-hSYN and AAV5-mCMV, encoding eGFP

61%
Platek R., Ziemlinska E., Czarkowska-Bauch J., Kugler S., Schachner M., Skup M.
Acta Neurobiologiae Experimentalis
|
2011
|
tom 71
|
nr 1
We compared the efficiency and specificity of in vivo transduction of spinal cord cells in adult, spinalized rats, with adeno-associated viral vectors: AAV1/2 and AAV5, with human synapsin (hSYN) and murine cytomegalovirus (mCMV) promoters, respectively. Both AAV vectors carried eGFP transgen, and were injected bilaterally to the lumbar L1 segment immediately after spinal transection at the Th10/11. At 5-6 weeks postlesion (1) the distribution and extent of eGFP expressing cells and fibers and (2) their phenotype (immunohistochemical identification; IHC) were determined. To evaluate virus expansion we compared distribution of eGFP signal at the microscopical reconstructions (parasagittal sections). A comparison between serotypes showed, that caudorostral range of cells expressing eGFP was comparable (AAV1/2 – 6.8 mm; AAV5 – 8 mm), with a core of transduced cells (AAV1/2 – 4.2/4.6 mm; AAV5 – 3.4/3.8 mm), surrounding the injection site. Fibers emerging from AAV1/2 -transduced cells reached the lesion border, many of them entered the lesion and occasionally went across the scar, whereas fibers of AAV5-transduced cells faded in a proximity of 300 µm to it. Dorsoventrally, cellular eGFP signal was detected in a gray matter of the subjects transduced with both serotypes, whereas only AAV5 - mCMV transduced cells also in a white matter. Morphology of eGFP expressing cells indicated that both serotypes transduced interneurons and large neurons of Lamina IX. IHC documented that AAV5 and, to a lesser extent, AAV1/2, transduced cholinergic cells (VAChT), whereas none of the transduced neurons were GABAergic (GAD67) or glutamatergic (VGLUT2). AAV5 transduced also glial cells, some identified as astrocytes (GFAP). In conclusion, both vectors efficiently transduce neurons in spinal animals; mCMV promoter drives eGFP expression also in glia. Support: Polish-German Project PBZ-MIN-001/P05/13, S007/PN/2007/01and statutory grant to Nencki Institute.
11

L1 overexpression in rats with complete spinal cord transection downregulates phosphacan and upregulates synaptophysin, GAP43 and Adcy1 expression

61%
Platek R., Grycz K., Wieckowska K., Czarkowska-Bauch J., Kugler S., Schachner M., Skup M.
Acta Neurobiologiae Experimentalis
|
2013
|
tom 73
|
nr Suppl.1
Recovery after spinal cord injury requires neuronal remodeling which is regulated by cell adhesion molecules (CAMs) and chondroitin sulfate proteoglycans (CSPGs). CSPG may be potentially both inhibitory and supportive of regenerative plasticity. To verify whether chronic (5 weeks) L1 CAM overexpression in transected spinal cord of the rat, proven to promote recovery in mice, affects CSPG phosphacan and markers of synaptic plasticity, adeno-associated viral vector encoding L1 protein (AAV5-L1) was injected into L1 lumbar segment, immediately after transection at Th10/11. Control group received AAV5-EGFP. AAV5-L1 transduced neurons and astrocytes below the lesion, resulting in 170-fold increase in L1 mRNA level at low thoracic segments (Th
12

Spinal cord transection leads to attenuation of determinants of GABAergic and glycinergic transmission not accompanied by changes in inhibitory inputs to motoneurons

61%
Ziemlinska E., Maciejewska A., Platek R., Gajewska-Wozniak O., Czarkowska-Banach J., Skup M.
Acta Neurobiologiae Experimentalis
|
2013
|
tom 73
|
nr Suppl.1
The data on the responses of inhibitory circuits to the spinal cord transection are conflicting. We examined the segmental distribution of determinants of GABAergic and glycinergic transmission in adult rats five weeks after complete spinal cord transection at Th9-10. Concentrations of the GABA and glycine (Gly) in segments below the lesion were evaluated in rats that did not receive any treatment. Decreases in GABA (24%) and Gly (26%) were found only in the lumbar L1-2 segments. Two other groups of spinal rats received microinjections of PBS (SP-PBS) or AAV- EGFP transgene (SPEGFP) to L1-2. Both led to GABA decrease (43% in L1-2 and 23% in L3-6 segments) and a decrease in mRNA for GAD67 (43% in L1-2 in both groups and 10% in L3-6 segment of SP-PBS vs 49% in L3-6 of SP-EGFP rats). The respective decreases in mRNA for Gly transporter GlyT2 were 68 vs. 72% in L1-2 and 29 vs. 76% in L3-6 segments. These changes were not accompanied by changes in the density of GABAergic/glycinergic network and inputs to motoneurons identified with GAD67/GlyT2 immunostaining. We conclude that albeit spinalization does not reduce inhibitory inputs to lumbar motoneurons it leads to long-term impairment in presynaptic determinants of inhibitory neurotransmission which may attenuate inhibitory signaling. Support: NN401 324739 grant.
13

Locomotor exercise of spinal rats causes an increase in size of cholinergic terminals in extensor motor nuclei

51%
Czarkowska-Bauch J., Mankovskaya T., Zaremba M., Gajewska O., Ziemlinska E., Platek R., Mlodkowski M., Korczynski J., Skup M.
Acta Neurobiologiae Experimentalis
|
2009
|
tom 69
|
nr 3
Spinal cord transection causes dramatic, sustained decrease of vesicular acetylcholine transporter VAChT in terminals contacting motoneurons, as reported by Kitzman (2006, Exp Neurol 197). Cholinergic projection is known to regulate excitability of motoneurons during locomotion. The question arises if locomotor exercise of spinal, paraplegic animals might restore the role of this projection. Three groups of adult rats were tested: intact control (n=6), spinal (n=7) and spinal trained subjected to 5 weeks of treadmill locomotor training (n=8). Animals were spinalized at low thoracic segments. Gastrocnemius/soleus and anterior tibial motoneurons were prelabeled with fl uorescent dyes (FG, DY), injected to the muscles. VAChT immunoreactivity (IR) was detected using polyclonal Sigma antibody. We have found that the spinal cord transection caused a decrease of VAChT IR in boutons synapsing on cell bodies and proximal dendrites of motoneurons in L3 and L4 segments compared with that of intact rats. Surprisingly, training caused its further decay. Mean number of VAChT IR boutons did not differ consistently between groups. However, in the extensor motoneuron pools of trained animals the number of bigger VAChT IR boutons was clearly higher than in spinal non-trained and intact animals. The latter effect is in line with functional improvement of spinal trained animals, which is the most prominent in the support phase of locomotion. Supported by MSE P-N/029/2006 and N N401 0480 33 grants.
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