54 results on '"Michal Tichý"'
Search Results
2. A 5‐year‐old boy with super‐refractory status epilepticus and RANBP2 variant warranting life‐saving hemispherotomy
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Barbora Straka, Miroslav Koblížek, Barbora Splítková, Radka Valkovičová, Lenka Krsková, Markéta Kalinová, Markéta Vlčková, Josef Zámečník, Petra Laššuthová, Lucie Sedláčková, David Staněk, Alice Maulisová, Michal Tichý, Martin Kynčl, and Pavel Kršek
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epilepsy surgery ,focal cortical dysplasia ,hemispherotomy ,RANBP2 ,refractory status epilepticus ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Focal cortical dysplasia (FCD) represents the most common cause of drug‐resistant epilepsy in adult and pediatric surgical series. However, genetic factors contributing to severe phenotypes of FCD remain unknown. We present a patient with an exceptionally rapid development of drug‐resistant epilepsy evolving in super‐refractory status epilepticus. We performed multiple clinical (serial EEG, MRI), biochemical (metabolic and immunological screening), genetic (WES from blood‐ and brain‐derived DNA), and histopathological investigations. The patient presented 1 month after an uncomplicated varicella infection. MRI was negative, as well as other biochemical and immunological examinations. Whole‐exome sequencing of blood‐derived DNA detected a heterozygous paternally inherited variant NM_006267.4(RANBP2):c.5233A>G p.(Ile1745Val) (Chr2[GRCh37]:g.109382228A>G), a gene associated with a susceptibility to infection‐induced acute necrotizing encephalopathy. No combination of anti‐seizure medication led to a sustained seizure freedom and the patient warranted induction of propofol anesthesia with high‐dose intravenous midazolam and continuous respiratory support that however failed to abort seizure activity. Brain biopsy revealed FCD type IIa; this finding led to the indication of an emergency right‐sided hemispherotomy that rendered the patient temporarily seizure‐free. Postsurgically, he remains on antiseizure medication and experiences rare nondisabling seizures. This report highlights a uniquely severe clinical course of FCD putatively modified by the RANBP2 variant. Plain Language Summary We report a case summary of a patient who came to our attention for epilepsy that could not be controlled with medication. His clinical course progressed rapidly to life‐threatening status epilepticus with other unusual neurological findings. Therefore, we decided to surgically remove a piece of brain tissue in order to clarify the diagnosis that showed features of a structural brain abnormality associated with severe epilepsy, the focal cortical dysplasia. Later, a genetic variant in a gene associated with another condition, was found, and we hypothesize that this genetic variant could have contributed to this severe clinical course of our patient.
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- 2024
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3. Current trends and outcomes of non-elective neurosurgical care in Central Europe during the second year of the COVID-19 pandemic
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Ondra Petr, Lukas Grassner, Freda M. Warner, Michaela Dedeciusová, Richard Voldřich, Philipp Geiger, Konstantin Brawanski, Sina Gsellmann, Laura C. Meiners, Richard Bauer, Sascha Freigang, Michael Mokry, Alexandra Resch, Thomas Kretschmer, Tobias Rossmann, Francisco Ruiz Navarro, Harald Stefanits, Andreas Gruber, Mathias Spendel, Christoph Schwartz, Christoph Griessenauer, Franz Marhold, Camillo Sherif, Jonathan P. Wais, Karl Rössler, Jakob J. Zagata, Martin Ortler, Wolfgang Pfisterer, Manfred Mühlbauer, Felipe A. Trivik-Barrientos, Johannes Burtscher, Lukáš Krška, Radim Lipina, Martin Kerekanič, Jiří Fiedler, Petr Kasík, Vladimír Přibáň, Michal Tichý, Vladimír Beneš, Petr Krůpa, Tomáš Česák, Robert Kroupa, Andrej Callo, Pavel Haninec, Daniel Pohlodek, David Krahulík, Alena Sejkorová, Martin Sameš, Josef Dvořák, Andriana Juričeková, Pavel Buchvald, Robert Tomáš, Jan Klener, Vilém Juráň, Martin Smrčka, Petr Linzer, Miroslav Kaiser, Dušan Hrabovský, Radim Jančálek, John L. K. Kramer, Claudius Thomé, and David Netuka
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Medicine ,Science - Abstract
Abstract Reflecting the first wave COVID-19 pandemic in Central Europe (i.e. March 16th–April 15th, 2020) the neurosurgical community witnessed a general diminution in the incidence of emergency neurosurgical cases, which was impelled by a reduced number of traumatic brain injuries (TBI), spine conditions, and chronic subdural hematomas (CSDH). This appeared to be associated with restrictions imposed on mobility within countries but also to possible delayed patient introduction and interdisciplinary medical counseling. In response to one year of COVID-19 experience, also mapping the third wave of COVID-19 in 2021 (i.e. March 16 to April 15, 2021), we aimed to reevaluate the current prevalence and outcomes for emergency non-elective neurosurgical cases in COVID-19-negative patients across Austria and the Czech Republic. The primary analysis was focused on incidence and 30-day mortality in emergency neurosurgical cases compared to four preceding years (2017–2020). A total of 5077 neurosurgical emergency cases were reviewed. The year 2021 compared to the years 2017–2019 was not significantly related to any increased odds of 30 day mortality in Austria or in the Czech Republic. Recently, there was a significant propensity toward increased incidence rates of emergency non-elective neurosurgical cases during the third COVID-19 pandemic wave in Austria, driven by their lower incidence during the first COVID-19 wave in 2020. Selected neurosurgical conditions commonly associated with traumatic etiologies including TBI, and CSDH roughly reverted to similar incidence rates from the previous non-COVID-19 years. Further resisting the major deleterious effects of the continuing COVID-19 pandemic, it is edifying to notice that the neurosurgical community´s demeanor to the recent third pandemic culmination keeps the very high standards of non-elective neurosurgical care alongside with low periprocedural morbidity. This also reflects the current state of health care quality in the Czech Republic and Austria.
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- 2022
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4. Distinctive Patterns of Seizure-Related White Matter Alterations in Right and Left Temporal Lobe Epilepsy
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Irena Buksakowska, Nikoletta Szabó, Lukáš Martinkovič, Péter Faragó, András Király, Jiří Vrána, Zsigmond Tamás Kincses, Jan Meluzín, Vlastimil Šulc, Martin Kynčl, Miloslav Roček, Michal Tichý, František Charvát, Daniel Hořínek, and Petr Marusič
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temporal lobe epilepsy (TLE) ,neuroimage analysis ,diffusion tensor image analysis ,white matter ,hippocampal sclerosis (HS) ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Background: We hypothesized that right and left temporal lobe epilepsy (RTLE and LTLE, respectively) have distinctive spatial patterns of white matter (WM) changes that can be differentiated and interpreted with the use of multiple diffusion parameters. We compared the global microstructure of fiber bundles with regard to WM alterations in both RTLE and LTLE, addressing some of the methodological issues of previous studies.Methods: Diffusion tensor imaging data from 17 patients with RTLE (age: 40.7 ± 10.4), 15 patients with LTLE (age: 37.3 ± 10.4), and 15 controls (age: 34.8 ± 11.2) were used in the study. WM integrity was quantified by fractional anisotropy (FA), mean diffusivity (MD), longitudinal diffusivity (LD), and radial diffusivity (RD). The diffusion parameters were compared between the groups in tracts representing the core of the fiber bundles. The volumes of hippocampi and amygdala were subsequently compared across the groups, while the data were adjusted for the effect of hippocampal sclerosis.Results: Significantly reduced FA and increased MD, LD, and RD were found bilaterally over widespread brain regions in RTLE. An increase in MD and RD values was observed in widespread WM fiber bundles ipsilaterally in LTLE, largely overlapping with regions where FA was lower, while no increase in LD was observed. We also found a difference between the LTLE and RTLE groups for the right hippocampal volume (with and without adjustment for HS), whereas no significant volume differences were found between patients and controls.Conclusions: It appears that patients with RTLE exhibit a more widespread pattern of WM alterations that extend far beyond the temporal lobe in both ipsilateral and contralateral hemisphere; furthermore, these changes seem to reflect more severe damage related to chronic degeneration. Conversely, more restrained changes in the LTLE may imply a pattern of less severe axonal damage, more restricted to ipsilateral hemisphere. Comprehensive finding of more prominent hippocampal atrophy in the RTLE raises an interesting issue of seizure-induced implications on gray matter and WM microstructure that may not necessarily mean a straightforward causal relationship. Further correlations of diffusion-derived metrics with neuropsychological and functional imaging measures may provide complementary information on underlying WM abnormalities with regard to functional hemispheric specialization.
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- 2019
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5. Cognitive performance in distinct groups of children undergoing epilepsy surgery—a single-centre experience
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Barbora Benova, Anezka Belohlavkova, Petr Jezdik, Alena Jahodová, Martin Kudr, Vladimir Komarek, Vilem Novak, Petr Liby, Robert Lesko, Michal Tichý, Martin Kyncl, Josef Zamecnik, Pavel Krsek, and Alice Maulisova
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Drug resistant epilepsy ,Paediatric epilepsy surgery ,Malformations of cortical development ,Cognitive outcome ,Long-term epilepsy-associated tumours ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Background We aimed first to describe trends in cognitive performance over time in a large patient cohort (n = 203) from a single tertiary centre for paediatric epilepsy surgery over the period of 16 years divided in two (developing—pre-2011 vs. established—post-2011). Secondly, we tried to identify subgroups of epilepsy surgery candidates with distinctive epilepsy-related characteristics that associate with their pre- and post-surgical cognitive performance. Thirdly, we analysed variables affecting pre-surgical and post-surgical IQ/DQ and their change (post- vs. pre-surgical). Methods We analysed IQ/DQ data obtained using standardized neuropsychological tests before epilepsy surgery and one year post-surgically, along with details of patient’s epilepsy, epilepsy surgery and outcomes in terms of freedom from seizures. Using regression analysis, we described the trend in post-operative IQ/DQ. Cognitive outcomes and the associated epilepsy- and epilepsy surgery-related variables were compared between periods before and after 2011. Using multivariate analysis we analysed the effect of individual variables on pre- and post-operative IQ/DQ and its change. Results Epilepsy surgery tends to improve post-surgical IQ/DQ, most significantly in patients with lower pre-surgical IQ/DQ, and post-surgical IQ/DQ strongly correlates with pre-surgical IQ/DQ (Rho = 0.888, p
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- 2019
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6. Extraskeletal myxoid chondrosarcoma: A study of 17 cases focusing on the diagnostic utility of INSM1 expression and presenting rare morphological variants associated with non-EWSR1::NR4A3 fusions
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Jiří Lenz, Natálie Klubíčková, Nikola Ptáková, Veronika Hájková, Petr Grossmann, Petr Šteiner, Zdeněk Kinkor, Marián Švajdler, Michal Michal, Petra Konečná, Dominika Macháčová, Pavel Hurník, Michal Tichý, František Tichý, Michal Kyllar, Luděk Fiala, Miroslav Kavka, and Michael Michal
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Pathology and Forensic Medicine - Abstract
Extraskeletal myxoid chondrosarcoma (EMC) is a rare sarcoma of uncertain lineage. Insulinoma-associated protein 1 (INSM1) has recently been described as a highly specific and sensitive immunohistochemical marker for EMC. The goal of this study was to evaluate the diagnostic significance of INSM1 immunohistochemistry in EMC. Furthermore, correlations between molecular and morphological findings were performed. Sixteen of 17 EMC cases were stained with the INSM1 antibody. Tumors with at least 5% INSM1-positive cells and any staining intensity were considered positive. Molecular testing was successfully performed in 12/17 cases. The immunohistochemical analysis detected 13 INSM1-positive (81%) and 3 INSM1-negative tumors (19%). The extent of the staining was classified as 1+ in 7 cases (44%), 2+ in 2 cases (13%), 3+ in 2 cases (13%) and 4+ in 2 cases (13%). Intensity of immunostaining was weak in 5 cases (31%), moderate in 2 cases (13%) and strong in 6 cases (38%). Molecular assays revealed 8 EWSR1::NR4A3 positive tumors (67%), 2 TAF15::NR4A3 positive tumors (17%), 1 TCF12::NR4A3 positive tumor (8%) and 1 NR4A3 positive tumor (8%) in which no other gene alteration was identified. Two of them, namely TCF12 positive and one TAF15 positive tumors, were highly cellular and partially associated with pseudopapillary architecture. Our study found that moderate/strong expression of INSM1 in more than 25% of tumor cells was present in only 31% of cases. Thus, the diagnostic utility of INSM1 is rather low. Two morphologically unique cases of non-EWSR1 rearranged EMC with an extremely rare pseudopapillary growth pattern are also reported.
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- 2023
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7. Survival and functional outcomes in paediatric thalamic and thalamopeduncular low grade gliomas
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Vladimír Beneš, Michal Zápotocký, Petr Libý, Jakub Táborský, Jana Blažková, David Sumerauer, Adéla Mišove, Ivana Perníková, Martin Kynčl, Lenka Krsková, Miroslav Koblížek, Josef Zámečník, Ondřej Bradáč, and Michal Tichý
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Male ,Treatment Outcome ,Thalamus ,Brain Neoplasms ,Humans ,Female ,Surgery ,Glioma ,Neurology (clinical) ,Child ,Magnetic Resonance Imaging ,Neurosurgical Procedures ,Retrospective Studies - Abstract
Childhood thalamopeduncular gliomas arise at the interface of the thalamus and cerebral peduncle. The optimal treatment is total resection but not at the cost of neurological function. We present long-term clinical and oncological outcomes of maximal safe resection.Retrospective review of prospectively collected data: demography, symptomatology, imaging, extent of resection, surgical complications, histology, functional and oncological outcome.During 16-year period (2005-2020), 21 patients were treated at our institution. These were 13 girls and 8 boys (mean age 7.6 years). Presentation included progressive hemiparesis in 9 patients, raised intracranial pressure in 9 patients and cerebellar symptomatology in 3 patients. The tumour was confined to the thalamus in 6 cases. Extent of resection was judged on postoperative imaging as total (6), near-total (6) and less extensive (9). Surgical complications included progression of baseline neurological status in 6 patients, and 5 of these gradually improved to preoperative status. All tumours were classified as low-grade gliomas. Disease progression was observed in 9 patients (median progression-free survival 7.3 years). At last follow-up (median 6.1 years), all patients were alive, median Lansky score of 90. Seven patients were without evidence of disease, 6 had stable disease, 7 stable following progression and 1 had progressive disease managed expectantly.Paediatric patients with low-grade thalamopeduncular gliomas have excellent long-term functional and oncological outcomes when gross total resection is not achievable. Surgery should aim at total resection; however, neurological function should not be endangered due to excellent chance for long-term survival.
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- 2022
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8. Synthesis of Polycyclic Hetero-Fused 7-Deazapurine Heterocycles and Nucleosides through C-H Dibenzothiophenation and Negishi Coupling
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Chao Yang, Lenka Poštová Slavětínská, Marianne Fleuti, Blanka Klepetářová, Michal Tichý, Soňa Gurská, Petr Pavliš, Petr Džubák, Marián Hajdúch, and Michal Hocek
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Zinc ,Colloid and Surface Chemistry ,Pyrimidines ,Cell Line, Tumor ,Oligonucleotides ,Nucleosides ,Oxides ,Deoxyribonucleosides ,General Chemistry ,Ribonucleosides ,Purine Nucleosides ,Biochemistry ,Catalysis - Abstract
A new approach for synthesizing polycyclic heterofused 7-deazapurine heterocycles and the corresponding nucleosides was developed based on C-H functionalization of diverse (hetero)aromatics with dibenzothiophene
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- 2022
9. Synthesis and Cytotoxic and Antiviral Activity Profiling of All‐Four Isomeric Series of Pyrido‐Fused 7‐Deazapurine Ribonucleosides
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Pavla Perlíková, Marian Hajduch, Blanka Klepetářová, Martina Medvedíková, Nemanja Milisavljevic, Helena Mertlíková-Kaiserová, Petr Džubák, Barbora Lišková, Jana Trylčová, Eva Tloušťová, Radek Pohl, Michal Tichý, Michal Hocek, Ondřej Hodek, Lucia Veselovská, Soňa Gurská, and Natálie Kudlová
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Glycosylation ,Pyrimidine ,010405 organic chemistry ,Stereochemistry ,Organic Chemistry ,Total synthesis ,Antineoplastic Agents ,General Chemistry ,010402 general chemistry ,Antiviral Agents ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Structure-Activity Relationship ,chemistry.chemical_compound ,chemistry ,Nucleophile ,Purines ,Pyridine ,Ribonucleosides ,Derivatization ,Selectivity ,DNA - Abstract
All four isomeric series of novel 4-substituted pyrido-fused 7-deazapurine ribonucleosides possessing the pyridine nitrogen atom at different positions were designed and synthesized. The total synthesis of each isomeric fused heterocycle through multistep heterocyclization was followed by glycosylation and derivatization at position 4 by cross-coupling reactions or nucleophilic substitutions. All compounds were tested for cytostatic and antiviral activity. The most active were pyrido[4',3':4,5]pyrimidine nucleosides bearing MeO, NH2 , MeS, or CH3 groups at position 4, which showed submicromolar cytotoxic effects and good selectivity for cancer cells. The mechanism involved activation by phosphorylation and incorporation to DNA where the presence of the modified ribonucleosides causes double-strand breaks and apoptosis.
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- 2020
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10. Polymerase Synthesis of DNA Containing Iodinated Pyrimidine or 7‐Deazapurine Nucleobases and Their Post‐synthetic Modifications through the Suzuki‐Miyaura Cross‐Coupling Reactions
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Michal Tichý, Michal Hocek, and Veronika Sýkorová
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chemistry.chemical_classification ,Halogenation ,biology ,Pyrimidine ,Oligonucleotide ,Stereochemistry ,DNA polymerase ,Organic Chemistry ,Molecular Conformation ,Nucleosides ,DNA ,DNA-Directed DNA Polymerase ,Biochemistry ,Nucleobase ,Deoxyribonucleoside ,chemistry.chemical_compound ,Pyrimidines ,chemistry ,Purines ,biology.protein ,Molecular Medicine ,Nucleotide ,Molecular Biology ,Polymerase - Abstract
All four iodinated 2'-deoxyribonucleoside triphosphates (dNTPs) derived from 5-iodouracil, 5-iodocytosine, 7-iodo-7-deazaadenine and 7-iodo-7-deazaguanine were prepared and studied as substrates for KOD XL DNA polymerase. All of the nucleotides were readily incorporated by primer extension and by PCR amplification to form DNA containing iodinated nucleobases. Systematic study of the Suzuki-Miyaura cross-coupling reactions with two bulkier arylboronic acids revealed that the 5-iodopyrimidines were more reactive and gave cross-coupling products both in the terminal or internal position in single-stranded oligonucleotides (ssONs) and in the terminal position of double-stranded DNA (dsDNA), whereas the 7-iodo-7-deazapurines were less reactive and gave cross-coupling products only in the terminal position. None of the four iodinated bases reacted in an internal position of dsDNA. These findings are useful for the use of the iodinated nucleobases for post-synthetic modification of DNA with functional groups for various applications.
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- 2021
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11. Current trends and outcomes of non-elective neurosurgical care in Central Europe during the second year of the COVID-19 pandemic
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Ondra Petr, Lukas Grassner, Freda M. Warner, Michaela Dedeciusová, Richard Voldřich, Philipp Geiger, Konstantin Brawanski, Sina Gsellmann, Laura C. Meiners, Richard Bauer, Sascha Freigang, Michael Mokry, Alexandra Resch, Thomas Kretschmer, Tobias Rossmann, Francisco Ruiz Navarro, Harald Stefanits, Andreas Gruber, Mathias Spendel, Christoph Schwartz, Christoph Griessenauer, Franz Marhold, Camillo Sherif, Jonathan P. Wais, Karl Rössler, Jakob J. Zagata, Martin Ortler, Wolfgang Pfisterer, Manfred Mühlbauer, Felipe A. Trivik-Barrientos, Johannes Burtscher, Lukáš Krška, Radim Lipina, Martin Kerekanič, Jiří Fiedler, Petr Kasík, Vladimír Přibáň, Michal Tichý, Vladimír Beneš, Petr Krůpa, Tomáš Česák, Robert Kroupa, Andrej Callo, Pavel Haninec, Daniel Pohlodek, David Krahulík, Alena Sejkorová, Martin Sameš, Josef Dvořák, Andriana Juričeková, Pavel Buchvald, Robert Tomáš, Jan Klener, Vilém Juráň, Martin Smrčka, Petr Linzer, Miroslav Kaiser, Dušan Hrabovský, Radim Jančálek, John L. K. Kramer, Claudius Thomé, and David Netuka
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Europe ,Multidisciplinary ,Hematoma, Subdural, Chronic ,COVID-19 ,Humans ,Pandemics ,Neurosurgical Procedures - Abstract
Reflecting the first wave COVID-19 pandemic in Central Europe (i.e. March 16th–April 15th, 2020) the neurosurgical community witnessed a general diminution in the incidence of emergency neurosurgical cases, which was impelled by a reduced number of traumatic brain injuries (TBI), spine conditions, and chronic subdural hematomas (CSDH). This appeared to be associated with restrictions imposed on mobility within countries but also to possible delayed patient introduction and interdisciplinary medical counseling. In response to one year of COVID-19 experience, also mapping the third wave of COVID-19 in 2021 (i.e. March 16 to April 15, 2021), we aimed to reevaluate the current prevalence and outcomes for emergency non-elective neurosurgical cases in COVID-19-negative patients across Austria and the Czech Republic. The primary analysis was focused on incidence and 30-day mortality in emergency neurosurgical cases compared to four preceding years (2017–2020). A total of 5077 neurosurgical emergency cases were reviewed. The year 2021 compared to the years 2017–2019 was not significantly related to any increased odds of 30 day mortality in Austria or in the Czech Republic. Recently, there was a significant propensity toward increased incidence rates of emergency non-elective neurosurgical cases during the third COVID-19 pandemic wave in Austria, driven by their lower incidence during the first COVID-19 wave in 2020. Selected neurosurgical conditions commonly associated with traumatic etiologies including TBI, and CSDH roughly reverted to similar incidence rates from the previous non-COVID-19 years. Further resisting the major deleterious effects of the continuing COVID-19 pandemic, it is edifying to notice that the neurosurgical community´s demeanor to the recent third pandemic culmination keeps the very high standards of non-elective neurosurgical care alongside with low periprocedural morbidity. This also reflects the current state of health care quality in the Czech Republic and Austria.
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- 2021
12. Synthesis of Cyclic and Acyclic Nucleoside Phosphonates and Sulfonamides Derived from 6‐(Thiophen‐2‐yl)‐7‐fluoro‐7‐deazapurine
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Sabina Smoleń, Vincent Malnuit, Michal Tichý, Michal Hocek, and Lenka Poštová Slavětínská
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Stereochemistry ,Chemistry ,Acyclic nucleoside ,Organic Chemistry ,Physical and Theoretical Chemistry - Published
- 2019
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13. Surgical explantation of a vagal nerve stimulator according to the magnetic resonance imaging protocol
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Martin Tomášek, Vojtěch Suchánek, Jiří Lisý, Michal Tichý, Petr Marusic, and Martin Bláha
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medicine.diagnostic_test ,business.industry ,Vagal nerve stimulator ,Medicine ,Surgery ,Magnetic resonance imaging ,Neurology (clinical) ,Nuclear medicine ,business - Published
- 2019
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14. Synthesis and Biological Profiling of Pyrazolo-Fused 7-Deazapurine Nucleosides
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Marian Hajduch, Lenka Poštová Slavětínská, Eva Tloušt’ová, Michal Tichý, Michal Hocek, Kateřina Bártová, Petr Pavlis, Marianne Fleuti, Soňa Gurská, and Petr Džubák
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Glycosylation ,Pyrimidine ,Stereochemistry ,Organic Chemistry ,Nucleosides ,Fluorescence ,Antiviral Agents ,In vitro ,chemistry.chemical_compound ,chemistry ,Nucleophile ,Purines ,Stereoselectivity ,Replicon ,Ribonucleosides ,Nucleoside - Abstract
A series of 8-substituted 1-methyl-1,4-dihydropyrazolo[3',4':4,5]pyrrolo[2,3-d]pyrimidine (methylpyrazolo-fused 7-deazapurine) ribonucleosides have been designed and synthesized. Two synthetic approaches to the key heterocyclic aglycon 7, (i) a six-step classical heterocyclization starting from 5-chloro-1-methyl-4-nitropyrazole and (ii) a three-step cross-coupling and cyclization approach starting from the zincated 4,6-dichloropyrimidine, gave comparable total yields of 18% vs 13%. The glycosylation of 7 was attempted by three different methods but only the Vorbruggen silyl-base protocol was efficient and stereoselective to give desired β-anomeric nucleoside intermediate 17A. Its nucleophilic substitutions or cross-coupling reactions at position 8 and deprotection of the sugar moiety gave eight derivatives of pyrazolo-fused deazapurine ribonucleosides, some of which were weakly fluorescent. Methyl, amino, and methylsulfanyl derivatives exerted submicromolar cytotoxic effects in vitro against a panel of cancer and leukemia cell lines as well as antiviral effects against hepatitis C virus in the replicon assay.
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- 2020
15. The asymptotic behaviour of the heat equation in a sheared unbounded strip
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Michal Tichý
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Shearing (physics) ,Semigroup ,Applied Mathematics ,Mathematical analysis ,FOS: Physical sciences ,Mathematical Physics (math-ph) ,Deformation (meteorology) ,Mathematics::Spectral Theory ,Sobolev space ,Dirichlet laplacian ,Heat equation ,Analysis ,Mathematical Physics ,Mathematics - Abstract
We show that the geometric deformation of shearing yields an improved decay rate for the heat semigroup associated with the Dirichlet Laplacian in an unbounded strip. The proof is based on the Hardy inequality due to the shearing established in [2] and the method of self-similar variables and weighted Sobolev spaces for the heat equation.
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- 2020
16. Synthesis, Photophysical Properties, and Biological Profiling of Benzothieno-Fused 7-Deazapurine Ribonucleosides
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Marian Hajduch, Michal Tichý, Petr Pavlis, Chao Yang, Michal Hocek, Petr Džubák, Radek Pohl, and Soňa Gurská
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Glycosylation ,Pyrimidine ,biology ,010405 organic chemistry ,Negishi coupling ,Oligonucleotide ,Stereochemistry ,DNA polymerase ,Organic Chemistry ,Nucleosides ,010402 general chemistry ,01 natural sciences ,Fluorescence ,Antiviral Agents ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Nucleophile ,Purines ,biology.protein ,Ribonucleosides ,DNA - Abstract
Two isomeric series of benzothieno-fused 7-deazapurine (benzo[4',5']thieno[3',2':4,5]- and benzo[4',5']thieno[2',3':4,5]pyrrolo[2,3-d]pyrimidine) ribonucleosides were designed and synthesized. Key steps of the synthesis included the Negishi coupling of zincated dichloropyrimidine with 2- or 3-iodobenzothiophene followed by azidation, thermal or photochemical cyclization, glycosylation, and final functionalization at position 6 through cross-couplings or nucleophilic substitutions. Deprotection gave the final nucleosides, some of which showed moderate cytotoxic and antiviral activity. Most of the free nucleosides showed moderate to strong fluorescence with emission maxima of 362-554 nm. 2'-Deoxyribonucleoside and its 5'-O-triphosphate were also prepared from benzothieno-fused 7-deazaadenine derivative, and the triphosphate was a good substrate for KOD XL DNA polymerase in primer extension synthesis of modified DNA which exerted a weak fluorescence which was slightly enhanced in double-stranded DNA as compared to single-stranded oligonucleotides.
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- 2020
17. Thienopyrrolo[2, 3-d ]pyrimidines, New Tricyclic Nucleobase Analogues: Synthesis and Biological Activities
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Sabina Smoleń, Radek Pohl, Lenka Poštová Slavětínská, Marian Hajduch, Michal Hocek, Michal Tichý, Petr Džubák, and Tomáš Deingruber
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0301 basic medicine ,chemistry.chemical_classification ,03 medical and health sciences ,030104 developmental biology ,010405 organic chemistry ,Stereochemistry ,Chemistry ,General Chemistry ,01 natural sciences ,0104 chemical sciences ,Nucleobase ,Tricyclic - Published
- 2018
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18. Trends in paediatric epilepsy surgery
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Michal Tichý, Vladimir Komarek, Petr Libý, Martin Kudr, Alice Maulisova, P. Ježdík, Martin Kyncl, Anežka Bělohlávková, Barbora Beňová, Alena Jahodova, and Pavel Krsek
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General Medicine - Abstract
Chirurgicka lecba epilepsie představuje významnou terapeutickou alternativu u pacientů s farmakorezistentni epilepsii. Klinika dětske neurologie 2. LF UK a FN Motol se v ramci Centra pro epilepsie Motol zabýva chirurgickou lecbou epilepsie u děti od roku 2000. K 1. 11. 2017 zde bylo realizovano 263 výkonů u 232 pacientů. V nasem clanku shrneme zakladni principy epileptochirurgie, předoperacni diagnostiky a představime výsledky epileptochirurgickeho programu dětske casti Centra pro epilepsie Motol vcetně aktualnich trendů. 80,7 % děti v nasem souboru je dva roky po operaci bez zachvatů. Zakladnim předpokladem uspěchu epileptochirurgie zůstava vcasne provedeni výkonu, ktere pro dětske pacienty představuje navic sanci na zachovani jejich kognitivniho potencialu.
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- 2018
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19. Synthesis and Cytostatic and Antiviral Profiling of Thieno-Fused 7-Deazapurine Ribonucleosides
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Radek Pohl, Klára Hejtmánková, Tomáš Oždian, Marian Hajduch, Sabina Smoleń, Michal Hocek, Petr Džubák, Michal Tichý, Soňa Gurská, Eva Tloušt’ová, and Barbora Lišková
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Glycosylation ,010405 organic chemistry ,Stereochemistry ,Negishi coupling ,Antineoplastic Agents ,Hepacivirus ,010402 general chemistry ,Antiviral Agents ,Hepatitis C ,01 natural sciences ,In vitro ,Leukemia cell line ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Nucleophile ,Purines ,Cell culture ,Cell Line, Tumor ,Neoplasms ,Drug Discovery ,Cancer cell ,Humans ,Molecular Medicine ,Ribonucleosides - Abstract
Two isomeric series of new thieno-fused 7-deazapurine ribonucleosides (derived from 4-substituted thieno[2',3':4,5]pyrrolo[2,3-d]pyrimidines and thieno[3',2':4,5]pyrrolo[2,3-d]pyrimidines) were synthesized by a sequence involving Negishi coupling of 4,6-dichloropyrimidine with iodothiophenes, nucleophilic azidation, and cyclization of tetrazolopyrimidines, followed by glycosylation and cross-couplings or nucleophilic substitutions at position 4. Most nucleosides (from both isomeric series) exerted low micromolar or submicromolar in vitro cytostatic activities against a broad panel of cancer and leukemia cell lines and some antiviral activity against HCV. The most active were the 6-methoxy, 6-methylsulfanyl, and 6-methyl derivatives, which were highly active to cancer cells and less toxic or nontoxic to fibroblasts.
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- 2017
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20. LGG-46. MOLECULAR CHARACTERIZATION OF HEMISPHERIC LOW-GRADE GLIOMAS IN CHILDREN
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Lenka Krskova, Ivana Pernikova, Adela Misove, Jan Starý, Josef Zamecnik, Michal Tichý, Petr Libý, Ales Vicha, Michal Zápotocký, Kateřina Váňová, Jakub Táborský, Martin Kyncl, and David Sumerauer
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Cancer Research ,Pathology ,medicine.medical_specialty ,Oncology ,business.industry ,Medicine ,Low Grade Glioma ,AcademicSubjects/MED00300 ,AcademicSubjects/MED00310 ,Neurology (clinical) ,business ,neoplasms - Abstract
BACKGROUND Heterogeneous pathology in hemispheric low-grade gliomas (hemLGG) stress the importance of molecular testing in terms of prognosis prediction and targeted therapy options. METHODS Demographic data was collected and targeted genomic approach was employed in the single institutional study. RT-PCR was used to screen for KIAA1549-BRAF fusion and FGFR1 tyrosine-kinase domain duplication (FGFR1-ITD). Direct sequencing evaluated point mutations (BRAF ex15 and ex11, FGFR1 ex12 and ex14). Samples with no detected alteration were subjected to panel RNA-sequencing (FusionPlex Archer Diagnostics). RESULTS Within 2000–2019 were diagnosed 76 patients with hemLGG (median age 11.1y, range 0.0y–18.5y) comprising predominantly of ganglioglioma, dysembryoplastic neuroepithelial tumors, and diffuse astrocytoma. 40 % of hemLGG were characterized by BRAF alterations with over 2/3 of those cases harboring BRAF point mutations (two BRAFex11, 12 BRAFV600E). Notably, BRAF fusions were uncommon and detected only in six patients (two KIAA-BRAF fusion, two minor oncogenic BRAF variants, two non-KIAA BRAF fusion). 25 % of alterations were found in genes for receptor tyrosine kinases, consisting of seven patients with FGFR1-ITD, three FGFR2/3 fusions, two FGFR1 mutations, two ALK fusions, and one ROS fusion. Out of MAP kinase pathway, the most frequent alteration was IDH1 mutations (n=9). Two angiocentric gliomas were characterized by MYB-QKI fusion. CONCLUSION Targeted sequencing combined with RNA-sequencing is feasible to establish molecular diagnosis in majority of cases and reveal new and rare alterations. Significant prevalence of non-BRAF alterations explains heterogeneity among hemLGG.
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- 2020
21. Distinctive Patterns of Seizure-Related White Matter Alterations in Right and Left Temporal Lobe Epilepsy
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András Király, Petr Marusic, Michal Tichý, František Charvát, Lukas Martinkovic, Zsigmond Tamás Kincses, Daniel Hořínek, Martin Kyncl, Jiří Vrána, Vlastimil Sulc, Nikoletta Szabó, Péter Faragó, Jan Meluzín, Irena Buksakowska, and Miloslav Rocek
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medicine.medical_specialty ,hippocampal sclerosis (HS) ,Audiology ,lcsh:RC346-429 ,030218 nuclear medicine & medical imaging ,Temporal lobe ,White matter ,03 medical and health sciences ,Epilepsy ,0302 clinical medicine ,Fractional anisotropy ,medicine ,neuroimage analysis ,diffusion tensor image analysis ,lcsh:Neurology. Diseases of the nervous system ,Original Research ,Hippocampal sclerosis ,business.industry ,Neuropsychology ,medicine.disease ,temporal lobe epilepsy (TLE) ,Functional imaging ,medicine.anatomical_structure ,Neurology ,Neurology (clinical) ,business ,white matter ,030217 neurology & neurosurgery ,Diffusion MRI - Abstract
Background: We hypothesized that right and left temporal lobe epilepsy (RTLE and LTLE, respectively) have distinctive spatial patterns of white matter (WM) changes that can be differentiated and interpreted with the use of multiple diffusion parameters. We compared the global microstructure of fiber bundles with regard to WM alterations in both RTLE and LTLE, addressing some of the methodological issues of previous studies. Methods: Diffusion tensor imaging data from 17 patients with RTLE (age: 40.7 ± 10.4), 15 patients with LTLE (age: 37.3 ± 10.4), and 15 controls (age: 34.8 ± 11.2) were used in the study. WM integrity was quantified by fractional anisotropy (FA), mean diffusivity (MD), longitudinal diffusivity (LD), and radial diffusivity (RD). The diffusion parameters were compared between the groups in tracts representing the core of the fiber bundles. The volumes of hippocampi and amygdala were subsequently compared across the groups, while the data were adjusted for the effect of hippocampal sclerosis. Results: Significantly reduced FA and increased MD, LD, and RD were found bilaterally over widespread brain regions in RTLE. An increase in MD and RD values was observed in widespread WM fiber bundles ipsilaterally in LTLE, largely overlapping with regions where FA was lower, while no increase in LD was observed. We also found a difference between the LTLE and RTLE groups for the right hippocampal volume (with and without adjustment for HS), whereas no significant volume differences were found between patients and controls. Conclusions: It appears that patients with RTLE exhibit a more widespread pattern of WM alterations that extend far beyond the temporal lobe in both ipsilateral and contralateral hemisphere; furthermore, these changes seem to reflect more severe damage related to chronic degeneration. Conversely, more restrained changes in the LTLE may imply a pattern of less severe axonal damage, more restricted to ipsilateral hemisphere. Comprehensive finding of more prominent hippocampal atrophy in the RTLE raises an interesting issue of seizure-induced implications on gray matter and WM microstructure that may not necessarily mean a straightforward causal relationship. Further correlations of diffusion-derived metrics with neuropsychological and functional imaging measures may provide complementary information on underlying WM abnormalities with regard to functional hemispheric specialization.
- Published
- 2019
22. BMI and Odds of Endometrial Adenocarcinoma in Czech Women - a Case Control Study
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Dominika Plancikova, Martina Chodacká, Marek Majdan, Michal Tichý, and Hana Ptáčková
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medicine.medical_specialty ,Population ,Overweight ,Adenocarcinoma ,Body Mass Index ,medicine ,Odds Ratio ,Humans ,Obesity ,Risk factor ,education ,Czech Republic ,education.field_of_study ,Obstetrics ,business.industry ,Incidence (epidemiology) ,Case-control study ,medicine.disease ,Endometrial Neoplasms ,Oncology ,Case-Control Studies ,Population study ,Female ,medicine.symptom ,business ,Body mass index - Abstract
Introduction The incidence of malignant tumors of the uterine body is increasing in the Czech Republic. Endometrial adenocarcinoma is one of the most frequent morphological types. Obesity or even overweight is a risk factor for the development of this disease. More accurate stratification of risk relative to body mass index (BMI) has not yet been determined in the Czech Republic, although the risk of overweight (BMI 25-29.9) has been reported in one study as comparable to that of first or second degree obesity (BMI 30-30.9). Patients and methods The study population included 376 women of Caucasian race diagnosed with endometrial adenocarcinoma, with BMI measured simultaneously, in 2005-2017. A control group consisted of an equal number of age-matched women not diagnosed with any oncological or gynecological disease. These two files were statistically processed. Results Odds (OR, 95% CI) relative to normal weight women, overweight women were at 2.26-times higher odds of endometrial adenocarcinoma, and women with obesity were at 5.18-8.67-, and 24.70-times higher odds, depending on the severity of obesity. Conclusion The hypothesis that overweight represents same risk for the development of endometrial adenocarcinoma, as lower degrees of obesity was not verified. However overweight is serious risk for endometrial adenocarcinoma development. The odds of endometrial adenocarcinoma is correlated with increasing BMI and in the population studied is higher than reported previously for all endometrial carcinoma subtypes. This work was carried out with the support of an internal grant of Krajska zdravotni, a.s., for the years 2017-2019: IGA217129002. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 29. 4. 2019 Accepted: 22. 7. 2019.
- Published
- 2019
23. A novel effective paradigm of intraoperative electrical stimulation mapping in children
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P. Ježdík, Alena Jahodova, Robert Lesko, Martin Kudr, Petr Liby, Michal Tichý, Pavel Čelakovský, Pavel Krsek, Radek Janca, Anežka Bělohlávková, and Barbora Beňová
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medicine.medical_specialty ,Motor area ,business.industry ,Intractable epilepsy ,Stimulation ,General Medicine ,medicine.disease ,03 medical and health sciences ,Epilepsy ,0302 clinical medicine ,Physical medicine and rehabilitation ,medicine.anatomical_structure ,Age groups ,Patient age ,030220 oncology & carcinogenesis ,medicine ,Epilepsy surgery ,business ,030217 neurology & neurosurgery ,Motor cortex - Abstract
OBJECTIVEResective epilepsy surgery is an established treatment method for children with focal intractable epilepsy, but the use of this method introduces the risk of postsurgical motor deficits. Electrical stimulation mapping (ESM), used to define motor areas and pathways, frequently fails in children. The authors developed and tested a novel ESM protocol in children of all age categories.METHODSThe ESM protocol utilizes high-frequency electric cortical stimulation combined with continuous intraoperative motor-evoked potential (MEP) monitoring. The relationships between stimulation current intensity and selected presurgical and surgery-associated variables were analyzed in 66 children (aged 7 months to 18 years) undergoing 70 resective epilepsy surgeries in proximity to the motor cortex or corticospinal tracts.RESULTSESM elicited MEP responses in all children. Stimulation current intensity was associated with patient age at surgery and date of surgery (F value = 6.81, p < 0.001). Increase in stimulation current intensity predicted postsurgical motor deficits (F value = 44.5, p < 0.001) without effects on patient postsurgical seizure freedom (p > 0.05).CONCLUSIONSThe proposed ESM paradigm developed in our center represents a reliable method for preventing and predicting postsurgical motor deficits in all age groups of children. This novel ESM protocol may increase the safety and possibly also the completeness of epilepsy surgery. It could be adopted in pediatric epilepsy surgery centers.
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- 2019
24. Synthesis and anti-trypanosomal activity of 3′-fluororibonucleosides derived from 7-deazapurine nucleosides
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Martina Slapničková, Samanta Rožánková, Van Hai Nguyen, Michal Tichý, A. Michael Downey, Eva Tloušťová, Eva Doleželová, Michal Hocek, Alena Zíková, and Radek Pohl
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Glycosylation ,Antiparasitic ,medicine.drug_class ,Trypanosoma brucei gambiense ,Trypanosoma brucei brucei ,Clinical Biochemistry ,Pharmaceutical Science ,Trypanosoma brucei ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,Parasitic Sensitivity Tests ,Cell Line, Tumor ,parasitic diseases ,Drug Discovery ,medicine ,Humans ,African trypanosomiasis ,Cytotoxicity ,Molecular Biology ,Molecular Structure ,biology ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Fibroblasts ,biology.organism_classification ,medicine.disease ,Trypanocidal Agents ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Molecular Medicine ,Ribonucleosides - Abstract
Trypanosoma brucei parasites cause Human African Trypanosomiasis and the current drugs for its treatment are often inefficient and toxic. This urges the need to development of new antitrypanosomal agents. We report the synthesis and biological profiling of 3′-deoxy-3′-fluororibonucleosides derived from 7-deazaadenine nucleosides bearing diverse substituents at position 7. They were synthesized through glycosylation of 6-chloro-7-bromo- or -7-iodo-7-deazapurine with protected 3′-fluororibose followed by cross-coupling reactions at position 7 and/or deprotection. Most of the title nucleosides displayed micromolar or submicromolar activity against Trypanosoma brucei brucei. The most active were the 7-bromo- and 7-iododerivatives which exerted double-digit nanomolar activity against T. b. brucei and T. b. gambiense and no cytotoxicity and thus represent promising candidates for further development.
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- 2021
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25. Sugar modified pyrimido[4,5-b]indole nucleosides: synthesis and antiviral activity
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Marian Hajduch, Radek Pohl, Michal Hocek, Michal Tichý, Juraj Konč, Petr Džubák, and Jan Hodek
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0301 basic medicine ,Pharmacology ,Indole test ,Glycosylation ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Organic Chemistry ,Pharmaceutical Science ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Nucleophile ,Arabinonucleosides ,Drug Discovery ,Molecular Medicine ,Sugar moiety ,Sugar ,IC50 - Abstract
Three types of sugar modified pyrimido[4,5-b]indole nucleosides (2′-deoxy-2′-fluororibo-, 2′-deoxy-2′-fluoroarabino- and arabinonucleosides) were synthesized by glycosylation of 4,6-dichloropyrimido[4,5-b]indole followed by modification of sugar moiety and introduction of substituents into position 4 by cross-coupling reactions or nucleophilic substitutions. Some 2′-fluororibo- and 2′-fluoroarabinonucleosides displayed interesting anti-HCV activities (IC50 = 1.6–20 μM) and the latter compounds also some anti-dengue activities (IC50 = 10.8–40 μM).
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- 2017
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26. Invasive aspergillosis following the heart transplantation - A case report
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Július Godava, Jan Krejčí, Eva Ozábalová, Petr Němec, Michal Tichý, Marta Pažourková, Petr Hude, Tomáš Honek, and Lenka Špinarová
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0301 basic medicine ,Voriconazole ,Heart transplantation ,medicine.medical_specialty ,Heart disease ,business.industry ,medicine.medical_treatment ,030106 microbiology ,Respiratory infection ,030204 cardiovascular system & hematology ,Aspergillosis ,medicine.disease ,3. Good health ,Surgery ,Sepsis ,03 medical and health sciences ,0302 clinical medicine ,Heart failure ,medicine ,Cardiology and Cardiovascular Medicine ,business ,Cause of death ,medicine.drug - Abstract
According to the ISHLT registry infectious complications are the leading cause of death in the first year after heart transplantation. Presented case report describes the fate of 63-year-old patient with heart failure due to coronary artery heart disease, which in March 2012, underwent a heart transplantation. In May comes with symptoms of respiratory infection. Diagnosed invasive aspergillus pneumonia, for which deployed specific treatment with voriconazole. For unsatisfactory effect enhanced by the addition of amphotericin B. Despite all the care patient a month after diagnosis dies of sepsis. A subsequent autopsy found the cause of death: abscessing necrotizing bronchopneumonia, but the surprise was the absence of fungal elements both by microscopy and cultivation.
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- 2016
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27. Correction to 'Synthesis and Cytotoxic and Antiviral Profiling of Pyrrolo- and Furo-Fused 7-Deazapurine Ribonucleosides'
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Sabina Smoleń, Yiqian Wenren, Pavla Perlíková, Noor-Ul-Ain Khalid, Barbora Lišková, Blanka Klepetářová, Ivo Frydrych, Petr Džubák, Anna Tokarenko, Michal Tichý, Soňa Gurská, Marian Hajduch, Michal Hocek, Helena Mertlíková-Kaiserová, Pawel Znojek, Natálie Táborská, Eva Tloušt’ová, Lenka Poštová Slavětínská, Rebecca R. Laposa, and Radek Pohl
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Chemistry ,Drug Discovery ,Molecular Medicine ,Profiling (information science) ,Cytotoxic T cell ,Computational biology - Published
- 2019
28. (3R,6E)-nerolidol, a fertility-related volatile secreted by the queens of higher termites (Termitidae: Syntermitinae)
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Michal Tichý, Jana Havlíčková, Pavlína Kyjaková, Vladimír Vrkoslav, Klára Dolejšová, Robert Hanus, and Blanka Kalinová
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0106 biological sciences ,Male ,Subfamily ,media_common.quotation_subject ,Zoology ,Fertility ,Isoptera ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Pheromones ,03 medical and health sciences ,chemistry.chemical_compound ,Hemolymph ,Animals ,Social Behavior ,Neoteny ,030304 developmental biology ,Nerolidol ,media_common ,0303 health sciences ,biology ,biology.organism_classification ,Animal Communication ,010602 entomology ,Termitidae ,chemistry ,Sex pheromone ,Queen (butterfly) ,Female ,Sesquiterpenes - Abstract
The queens of advanced social insects maintain their reproductive monopoly by using exocrine chemicals. The chemistry of these “queen pheromones” in termites is poorly known. We show that primary queens of four higher termites from the subfamily Syntermitinae (Embiratermes neotenicus, Silvestritermes heyeri, Labiotermes labralis, and Cyrilliotermes angulariceps) emit significant amounts of the sesquiterpene alcohol (E)-nerolidol. It is the dominant analyte in queen body washes; it is present on the surface of eggs, but absent in kings, workers, and soldiers. In E. neotenicus, it is also produced by replacement neotenic queens, in quantities correlated with their fertility. Using newly synthesised (3R,6E)-nerolidol, we demonstrate that the queens of this species produce only the (R) enantiomer. It is distributed over the surface of their abdomen, in internal tissues, and in the haemolymph, as well as in the headspace of the queens. Both (R) and (S) enantiomers are perceived by the antennae of E. neotenicus workers. The naturally occurring (R) enantiomer elicited a significantly larger antennal response, but it did not show any behavioural effect. In spite of technical difficulties encountered in long-term experiments with the studied species, (3R,6E)-nerolidol remains among eventual candidates for the role in queen fertility signalling.
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- 2018
29. Synthesis and Cytotoxic and Antiviral Profiling of Pyrrolo- and Furo-Fused 7-Deazapurine Ribonucleosides
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Anna Tokarenko, Petr Džubák, Sabina Smoleń, Yiqian Wenren, Rebecca R. Laposa, Marian Hajduch, Noor-Ul-Ain Khalid, Soňa Gurská, Michal Tichý, Helena Mertlíková-Kaiserová, Pavla Perlíková, Barbora Lišková, Blanka Klepetářová, Eva Tloušt’ová, Ivo Frydrych, Natálie Táborská, Radek Pohl, Michal Hocek, Lenka Poštová Slavětínská, and Pawel Znojek
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0301 basic medicine ,Glycosylation ,Pyrimidine ,Stereochemistry ,DNA damage ,Antineoplastic Agents ,Chemistry Techniques, Synthetic ,010402 general chemistry ,01 natural sciences ,Antiviral Agents ,03 medical and health sciences ,chemistry.chemical_compound ,Structure-Activity Relationship ,Nucleophile ,Cell Line, Tumor ,Drug Discovery ,Structure–activity relationship ,Humans ,Nucleotide ,Pyrroles ,Furans ,chemistry.chemical_classification ,RNA ,0104 chemical sciences ,Addition/Correction ,030104 developmental biology ,chemistry ,Purines ,Molecular Medicine ,Ribonucleosides ,DNA - Abstract
Three series of isomeric pyrrolo- and furo-fused 7-deazapurine ribonucleosides were synthesized and screened for cytostatic and antiviral activity. The synthesis was based on heterocyclizations of hetaryl-azidopyrimidines to form the tricyclic heterocyclic bases, followed by glycosylation and final derivatizations through cross-coupling reactions or nucleophilic substitutions. The pyrrolo[2',3':4,5]pyrrolo[2,3- d]pyrimidine and furo[2',3':4,5]pyrrolo[2,3- d]pyrimidine ribonucleosides were found to be potent cytostatics, whereas the isomeric pyrrolo[3',2',4,5]pyrrolo[2,3- d]pyrimidine nucleosides were inactive. The most active were the methyl, methoxy, and methylsulfanyl derivatives exerting submicromolar cytostatic effects and good selectivity toward cancer cells. We have shown that the nucleosides are activated by intracellular phosphorylation and the nucleotides get incorporated to both RNA and DNA, where they cause DNA damage. They represent a new type of promising candidates for preclinical development toward antitumor agents.
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- 2018
30. Synthesis and antiproliferative properties of new hydrophilic esters of triterpenic acids
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Lucie Rárová, Barbara Bednarczyk-Cwynar, Jana Krasulová, Barbara Eignerova, Jan Sarek, Romana Christova, Marian Hajduch, Milan Urban, Miroslav Kvasnica, and Michal Tichý
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0301 basic medicine ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,Triterpenoid ,Betulinic acid ,Cell Line, Tumor ,Drug Discovery ,Monosaccharide ,Humans ,Model set ,Cytotoxicity ,IC50 ,Cell Proliferation ,Pharmacology ,chemistry.chemical_classification ,Ethanol ,010405 organic chemistry ,Spectrum Analysis ,Organic Chemistry ,Esters ,General Medicine ,Combinatorial chemistry ,Triterpenes ,0104 chemical sciences ,Dihydrobetulinic acid ,030104 developmental biology ,chemistry ,Drug Screening Assays, Antitumor - Abstract
To improve the properties of cytotoxic triterpenoid acids 1–5, a large set of hydrophilic esters was synthesized. We choose betulinic acid (1), dihydrobetulinic acid (2), 21-oxoacid 3 along with highly active des-E lupane acids 4 and 5 as a model set of compounds for esterification of which the properties needed to be improved. As ester moieties were used - methoxyethanol and 2-(2-methoxyethoxy)ethanol and glycolic unit (type a-d), pyrrolidinoethanol, piperidinoethanol and morpholinoethanol (type f-h), and monosaccharide groups (type i-l). As a result, 56 triterpenic esters (49 new compounds) were obtained and their cytotoxicity on four cancer cell lines and normal human fibroblasts was tested. All new compounds were fully soluble at all tested concentrations, which used to be a problem of the parent compounds 1 and 2. 16 compounds had IC50
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- 2017
31. Prospective Evaluation of Free Energy Calculations for the Prioritization of Cathepsin L Inhibitors
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Maude Giroud, Rainer E. Martin, Jérôme Hert, Lingle Wang, Robert Abel, François Diederich, Andreas Kuglstatter, Michal Tichý, Jörg Benz, Shaughnessy Robinson, Tanja Schirmeister, and Bernd Kuhn
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0301 basic medicine ,Prioritization ,Molecular model ,Halogenation ,Stereochemistry ,Cathepsin L ,Computational biology ,01 natural sciences ,Molecular Docking Simulation ,Prospective evaluation ,03 medical and health sciences ,0103 physical sciences ,Drug Discovery ,Humans ,Enzyme Inhibitors ,Binding Sites ,010304 chemical physics ,biology ,Chemistry ,030104 developmental biology ,Pyrimidines ,Docking (molecular) ,Drug Design ,biology.protein ,Molecular Medicine ,Thermodynamics ,Protein Binding - Abstract
Improving the binding affinity of a chemical series by systematically probing one of its exit vectors is a medicinal chemistry activity that can benefit from molecular modeling input. Herein, we compare the effectiveness of four approaches in prioritizing building blocks with better potency: selection by a medicinal chemist, manual modeling, docking followed by manual filtering, and free energy calculations (FEP). Our study focused on identifying novel substituents for the apolar S2 pocket of cathepsin L and was conducted entirely in a prospective manner with synthesis and activity determination of 36 novel compounds. We found that FEP selected compounds with improved affinity for 8 out of 10 picks compared to 1 out of 10 for the other approaches. From this result and other additional analyses, we conclude that FEP can be a useful approach to guide this type of medicinal chemistry optimization once it has been validated for the system under consideration.
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- 2017
32. Synthesis and biological activity of benzo-fused 7-deazaadenosine analogues. 5- and 6-substituted 4-amino- or 4-alkylpyrimido[4,5-b]indole ribonucleosides
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Gina Bahador, Michal Hocek, Jan Weber, Yu-Jen Lee, Radek Pohl, Eva Tloušt’ová, and Michal Tichý
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Adenosine ,Indoles ,Cell Survival ,Stereochemistry ,Clinical Biochemistry ,Pharmaceutical Science ,HL-60 Cells ,Hepacivirus ,Antiviral Agents ,Biochemistry ,Catalysis ,Cell Line, Tumor ,Drug Discovery ,Nucleophilic substitution ,Humans ,Molecular Biology ,Indole test ,Chemistry ,Ligand ,Organic Chemistry ,Biological activity ,Hep G2 Cells ,Dengue Virus ,Stille reaction ,Molecular Medicine ,Ribonucleosides ,Palladium ,HeLa Cells - Abstract
Two series of new 4-aminopyrimido[4,5-b]indole ribonucleosides bearing phenyl or hetaryl group at position 5 or 6 have been prepared by Suzuki or Stille cross-coupling reactions employing X-Phos ligand with (het)arylboronic acids or stannanes. A series of 4-substituted nucleosides has been also prepared by Pd-catalyzed cross-couplings or nucleophilic substitution. Some of these compounds displayed moderate antiviral activities against HCV and dengue viruses.
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- 2013
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33. 6-Aryl-4-amino-pyrimido[4,5-b]indole 2'-deoxyribonucleoside triphosphates (benzo-fused 7-deaza-dATP analogues): Synthesis, fluorescent properties, enzymatic incorporation into DNA and DNA-protein binding study
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Radek Pohl, Pavla Perlíková, Michal Tichý, Andrea Bosáková, and Michal Hocek
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Glycosylation ,Indoles ,Stereochemistry ,DNA polymerase ,Base Pair Mismatch ,Clinical Biochemistry ,Pharmaceutical Science ,Deoxyribonucleosides ,DNA-Directed DNA Polymerase ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Single-stranded binding protein ,chemistry.chemical_compound ,Deoxyadenine Nucleotides ,Drug Discovery ,Escherichia coli ,Nucleotide ,Molecular Biology ,Fluorescent Dyes ,Indole test ,chemistry.chemical_classification ,biology ,Base Sequence ,010405 organic chemistry ,Oligonucleotide ,Escherichia coli Proteins ,Organic Chemistry ,0104 chemical sciences ,Deoxyribonucleoside ,DNA-Binding Proteins ,Spectrometry, Fluorescence ,chemistry ,biology.protein ,Molecular Medicine ,Oligonucleotide Probes ,DNA - Abstract
Four 6-substituted 4-amino-pyrimido[4,5-b]indole 2'-deoxyribonucleoside triphosphates (dA(BX)TPs) were prepared by glycosylation of 4,6-dichloropyrimidoindole followed by ammonolysis, cross-coupling and triphosphorylation. They were found to be moderate to good substrates for DNA polymerases in primer extension. They also exerted fluorescence with emission maxima 335-378nm. When incorporated to oligonucleotide probes, they did not show significant mismatch discrimination but the 6-benzofuryl 4-amino-pyrimido[4,5-b]indole nucleotide displayed a useful sensitivity to protein binding in experiment with SSB protein.
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- 2016
34. Synthesis and antiviral activity of 4,6-disubstituted pyrimido[4,5-b]indole ribonucleosides
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Hao Ying Xu, Michal Tichý, Radek Pohl, Fumiaki Yokokawa, Michal Hocek, Pei Yong Shi, and Yen Liang Chen
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Indole test ,Indoles ,Stereochemistry ,Chemistry ,Ligand ,Organic Chemistry ,Clinical Biochemistry ,Pharmaceutical Science ,Hep G2 Cells ,Hepacivirus ,Dengue Virus ,Virus Replication ,Ribonucleoside ,Antiviral Agents ,Biochemistry ,Catalysis ,Pyrimidines ,Cell Line, Tumor ,Drug Discovery ,Humans ,Molecular Medicine ,Ribonucleosides ,Molecular Biology ,Palladium ,Cell Proliferation - Abstract
A series of new pyrimido[4,5-b]indole ribonucleosides bearing phenyl or hetaryl group at position 4 has been prepared by selective Pd-catalyzed cross-coupling reactions of the corresponding protected 4,6-dichloropyrimido[4,5-b]indole ribonucleoside with (het)arylboronic acids or stannanes followed by deprotection. Further cross-couplings under harsher conditions and employing X-Phos ligand proceeded at the position 6 leading to 4,6-disubstituted pyrimido[4,5-b]indole ribonucleosides. Some of these compounds displayed antiviral activity against Dengue virus.
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- 2012
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35. [New options for therapeutic revascularization in lower extremity limb ischemia linked to the diabetic foot syndrome by autologous stem cell transplantation]
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Jakub, Svěcený, Eva, Syková, Michal, Tichý, and Jiří, Laštůvka
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Wound Healing ,Humans ,Syndrome ,Vascular Surgical Procedures ,Diabetic Foot ,Stem Cell Transplantation - Abstract
Type 2 diabetes incidence is growing worldwide. It is in up to 50% cases linked with diabetic foot syndrome. This is associated with peripheral neuropathy and peripheral artery disease which increases risk of defects with impaired healing. Resulting high number of amputations has major influence on the quality of life and constitutes serious clinical issue. In recent years numerous clinical studies have shown positive effect of new treatment modality using regenerative potential of the autologous stem cells transplantation. This review tries to summarize existing results of therapeutic revascularization using stem cell and to outline mechanism of their action.
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- 2015
36. [Embryonal Tumors with Multilayer Rosettes--Rare Central Nervous System Tumors in Infants]
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Emilia Kaiserova, Josef Zamecnik, Michal Tichý, Marek Pleško, and Kristína Husáková
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Male ,Pathology ,medicine.medical_specialty ,medicine.medical_treatment ,Central nervous system ,Lesion ,Medicine ,Humans ,Neuroectodermal Tumors, Primitive ,Chemotherapy ,medicine.diagnostic_test ,business.industry ,Brain Neoplasms ,Magnetic resonance imaging ,medicine.disease ,Facial nerve ,Magnetic Resonance Imaging ,Radiation therapy ,medicine.anatomical_structure ,Oncology ,Child, Preschool ,Medulloepithelioma ,medicine.symptom ,business ,Tomography, X-Ray Computed ,Ependymoblastoma - Abstract
Introduction The most recent findings show a histopathological, genetic and clinical uniformity in cases of tumors called embryonal tumors with multilayer rosettes. This group is composed of medulloepithelioma, ependymoblastoma and embryonal tumor with abundant neuropil and true rosettes. Amplification of locus 19q13.42, which includes C19MC cluster containing genes for microRNA, and also LIN28A positivity are present in all three entities. Dysregulation of epigenetic modifiers is very important in pathogenesis of the disease. These tumors manifest in little children (median less than 3 years of age); overall survival is 5-10%. Case report Almost three year-old boy diagnosed with brainstem tumor: meduloepithelioma, WHO grade IV confirmed by histological investigation. He presented with dysarthria, bulbar syndrome, central lesion of the facial nerve, quadriparesis with right-side dominancy. He received three induction cycles of chemotherapy from March to May 2014 (according to protocol COG ACNS0334). Only partial improvement of his clinical state was reached. Signs of an intracranial hypertension appeared resulting in VP shunt insertion; impairment of consciousness developed after the induction cycles and before any other treatment could be initiated. He underwent radiotherapy due to vital indication. After application of two fractions (boost in the center of the tumor), the patient became quickly comatose. Spinal cord metastasis was demarked by MRI scan (in the level of 3rd cervical vertebra). A bilateral infiltration in pulmonary parenchyma, according to a radiologist metastasis-wise, was detected by CT scan (histologisation of infiltration was not implemented). The patient died in August 2014--six months after manifestation of first symptoms. Conclusion We reported our first documented case of a patient with tumor from embryonal tumors with multilayer rosettes group in Slovakia. Nowadays, there is no effective treatment of these tumors. Research of molecules targeting to epigenetic modifiers would be one of the possible promises for future therapy.
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- 2015
37. Diffusion parameters of the extracellular space in human gliomas
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Eva Syková, Vladimír Beneš, Aleš Homola, Michal Tichý, Josef Zamecnik, and Lýdia Vargová
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Pathology ,medicine.medical_specialty ,Alpha (ethology) ,Biology ,Lambda ,medicine.disease ,Extracellular matrix ,Cellular and Molecular Neuroscience ,medicine.anatomical_structure ,Neurology ,Cerebral cortex ,Glioma ,medicine ,Extracellular ,Effective diffusion coefficient ,Astroglioma - Abstract
Tumor cell migration through the extracellular space (ECS) might be affected by its pore size and extracellular matrix molecule content. ECS volume fraction alpha (alpha = ECS volume/total tissue volume), tortuosity lambda (lambda(2) = free/apparent diffusion coefficient) and nonspecific uptake k' were studied by the real-time tetramethylammonium method in acute slices of human tissue. The diffusion parameters in temporal cortical tissue resected during surgical treatment of temporal lobe epilepsy (control) were compared with those in brain tumors. Subsequently, tumor slices were histopathologically classified according to the grading system of the World Health Organization (WHO), and proliferative activity was assessed. The average values of alpha, lambda, and k' in control cortex were 0.24, 1.55, and 3.66 x 10(-3)s(-1), respectively. Values of alpha, lambda, and k' in oligodendrogliomas did not significantly differ from controls. In pilocytic astrogliomas (WHO grade I) as well as in ependymomas (WHO grade II), alpha was significantly higher, while lambda and k' were unchanged. Higher values of alpha as well as lambda were found in low-grade diffuse astrocytomas (WHO grade II). In cellular regions of high-grade astrocytomas (WHO grade III and IV), alpha and lambda were further increased, and k' was significantly larger than in controls. Classic medulloblastomas (WHO grade IV) had an increased alpha, but not lambda or k', while in the desmoplastic type alpha and k' remained unchanged, but lambda was greatly increased. Tumor malignancy grade strongly corresponds to an increase in ECS volume, which is accompanied by a change in ECS structure manifested by an increase in diffusion barriers for small molecules.
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- 2003
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38. Trends in paediatric epilepsy surgery 2000–2016
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Alena Jahodova, Pavel Krsek, Michal Tichý, Martin Kudr, P. Ježdík, Vladimir Komarek, Alice Maulisova, Petr Libý, and Anežka Bělohlávková
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Pediatrics ,medicine.medical_specialty ,business.industry ,Paediatric epilepsy ,Pediatrics, Perinatology and Child Health ,Medicine ,Neurology (clinical) ,General Medicine ,business - Published
- 2017
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39. Epithelioid schwannoma
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Pavel Boček, Roman Kodet, and Michal Tichý
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Pathology ,medicine.medical_specialty ,business.industry ,Ultrastructure ,Medicine ,Immunohistochemistry ,General Medicine ,Schwannoma ,business ,medicine.disease - Published
- 1998
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40. Amebic Encephalitis Caused by Balamuthia mandrillaris in a Czech Child: Description of the First Case from Europe
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Eva Nohýnková, Jan Soukup, Michal Tichý, Roman Kodet, and Govinda S. Visvesvara
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Male ,Pathology ,medicine.medical_specialty ,Necrosis ,T-Lymphocytes ,Balamuthia ,Balamuthia mandrillaris ,Pathology and Forensic Medicine ,Fatal Outcome ,medicine ,Animals ,Humans ,Amoeba ,Fluorescent Antibody Technique, Indirect ,Immunodeficiency ,Granuloma ,Indirect immunofluorescence ,biology ,medicine.diagnostic_test ,Brain biopsy ,Brain ,Amebiasis ,Cell Biology ,Granulomatous encephalitis ,medicine.disease ,biology.organism_classification ,Magnetic Resonance Imaging ,Virology ,Czechoslovakia ,Child, Preschool ,Encephalitis ,medicine.symptom - Abstract
Summary We describe a fatal case of amebic encephalitis caused by Balamuthia mandrillaris in a 3-year-old Czech boy who had never traveled abroad. This is the first such infection reported in Europe. The diagnosis was established by brain biopsy, in which abundant trophozoites and a few round amebic cysts were identified. The presence of multiple nucleoli in some trophozoites suggested the organism to be Balamuthia mandrillaris and this was confirmed by indirect immunofluorescence. The amebae invaded brain tissue, including neurons, and blood vessel walls, causing thrombovasculitis. The tissue reaction was a subacute necrotizing and granulomatous encephalitis (GAE) with an infiltrate of CD4- and CD8-positive T-lymphocytes, B-lymphocytes, plasma cells and macrophages. The child, in whom no underlying immunodeficiency was demonstrated, died after 45 days. The mode of infection was not established. Postmortem examination of the brain revealed massive areas of necrosis and microscopic findings like those in the surgical specimen. In vitro isolation of B. mandrillaris was unsuccessful.
- Published
- 1998
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41. Synthesis and biological activity of thiophene fused 7-deazapurine ribonucleosides
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Michal Hocek and Michal Tichý
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chemistry.chemical_compound ,Chemistry ,Thiophene ,Organic chemistry ,Biological activity - Published
- 2014
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42. Chemistry and anatomy of the frontal gland in soldiers of the sand termite Psammotermes hybostoma
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Jana Krasulová, Robert Hanus, Michal Tichý, Jan Šobotník, Kateřina Kutalová, Irena Valterová, and David Sillam-Dussès
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Entomology ,Ecology ,General Medicine ,Anatomy ,Isoptera ,Biology ,biology.organism_classification ,Biochemistry ,Gas Chromatography-Mass Spectrometry ,Functional diversity ,Taxon ,Phylogenetics ,Biological dispersal ,Animals ,Chemical defense ,Psammotermes ,Egypt ,Rhinotermitidae ,Sesquiterpenes ,Ecology, Evolution, Behavior and Systematics - Abstract
A great diversity of defensive chemicals has been described in termite soldiers equipped with a unique defensive organ, the frontal gland. Along with the functional diversity of these compounds, reflecting the evolutionary history of particular lineages and their defensive strategies, a considerable degree of chemical variability often occurs among species and populations. Thus, the chemistry of termite defense may provide information on the phylogeny and geographic dispersal of species and populations. In this paper, we report on the anatomy of the frontal gland and on the diversity of soldier defensive chemicals in the sand termite, Psammotermes hybostoma, from nine colonies and five different localities in Egypt. Using gas chromatography–mass spectrometry, a total of 30 sesquiterpene hydrocarbons, or their oxygenated derivatives, were detected, and the chemical identity of most of them identified. In addition, a ketone, an ester, and a diterpene were identified in some colonies. Within colonies, the chemical composition was stable and did not differ among soldier size categories. However, there were pronounced quantitative and qualitative differences in frontal gland chemicals among colonies and geographic locations. The findings are discussed in a broader comparison with other termite taxa.
- Published
- 2011
43. Synthesis of 4-(het)aryl pyrimido[4,5-b]indole ribonucleosides
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Michal Tichý and Michal Hocek
- Subjects
Indole test ,chemistry.chemical_compound ,chemistry ,Stereochemistry ,Aryl ,Organic chemistry - Published
- 2011
- Full Text
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44. Clinical characteristics in patients with hippocampal sclerosis with or without cortical dysplasia
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Petr, Marusic, Martin, Tomásek, Pavel, Krsek, Hana, Krijtová, Jana, Zárubová, Josef, Zámecník, Milan, Mohapl, Vladimír, Benes, Michal, Tichý, and Vladimír, Komárek
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Adult ,Male ,Malformations of Cortical Development ,Sclerosis ,Adolescent ,Epilepsy, Temporal Lobe ,Humans ,Female ,Middle Aged ,Child ,Hippocampus ,Demography - Abstract
Mesial temporal lobe epilepsy (MTLE) with hippocampal sclerosis (HS) constitutes a distinct clinical syndrome with variable pathogenesis. Extrahippocampal regions may be affected in MTLE/HS, association with cortical dysplasia is common and temporal polar cortex is frequently involved in seizure onset. Patients with dual pathology may have favourable outcome from the surgery provided that both pathologies are removed. The aim of the study was to review clinical variables of MTLE/HS patients in order to distinguish preoperatively patients with associated microscopic cortical dysplasia in the temporal pole.A series of 38 patients with the clinical diagnosis of MTLE and histopathologically proven HS were analysed. Patients were divided into two groups on the basis of histopathological finding in the temporal polar cortex: HS associated with malformation of cortical development (group HS+, n = 19) and a group with isolated HS (group HS, n = 19). Demographic, clinical, electrographic and seizure semiology variables were obtained and their prevalence compared between both groups.At least one insult was identified in early childhood history of 18 patients in the HS group in comparison to 10 patients in the HS+ group (p0.01). Complicated febrile seizures were found in both groups with similar prevalence, the history of early childhood CNS infection prevailed in the HS group (p0.01). Absence of aura was reported in HS group only. Patients in the the HS+ group had earlier surgery (p0.05) but the seizure outcome was comparable between groups.Microscopic dual pathology is common in MTLE/HS patients. This group of patients is difficult to distinguish preoperatively on the basis of noninvasive electrographic features or ictal clinical semiology. Detailed information regarding the possible precipitating insult in the history may be of critical importance.
- Published
- 2008
45. Two cases of improvement of smooth pursuit eye movements after selective posterior rhizotomy
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Michal Tichý, P. Libý, D. Hoza, Martin Bojar, David Sturm, Rudolf Černý, Martin Vyhnalek, Daniel Hořínek, and M. Oweimrin
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Male ,medicine.medical_specialty ,genetic structures ,Adolescent ,medicine.medical_treatment ,education ,Fixation nystagmus ,Smooth pursuit ,Cerebral palsy ,Rhizotomy ,Physical medicine and rehabilitation ,Ocular Motility Disorders ,Medicine ,Humans ,Spasticity ,Child ,business.industry ,Cerebral Palsy ,Eye movement ,General Medicine ,medicine.disease ,Pursuit, Smooth ,Muscle Spasticity ,Anesthesia ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Female ,Neurology (clinical) ,Neurosurgery ,medicine.symptom ,business - Abstract
Selective posterior rhizotomy (SPR) represents a standard neurosurgical approach in the treatment of spasticity in children with cerebral palsy (CP). Beside the reduction of spasticity in lower limbs, SPR may have suprasegmental effects, considerably above the surgery site. In this communication, we report on the improvement of smooth pursuit eye movements (SPEM) in two children after SPR. Four children with CP underwent SPR. Eye movements were registered by infrared video-oculography before and after the surgery. The analysis of SPEM showed the improvement of the correlation coefficient of the eye response to the stimulus after SPR in two subjects. Improvement of SPEM performance was largely due to suppression of spontaneous fixation nystagmus. SPR may lead to the improvement of SPEM in children with CP. The influence of SPEM improvement on quality of life in a group of severely disabled nonambulant children with CP remains to be assessed.
- Published
- 2008
46. 35. Practical value of quantitative EEG in epilepsy surgery planning
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Vladimir Komarek, P. Ježdík, Roman Cmejla, Pavel Krsek, Radek Janca, P. Jiruška, Michal Tichý, Petr Marusic, and Tomas Havel
- Subjects
medicine.medical_specialty ,Cognition ,Cortical dysplasia ,Audiology ,medicine.disease ,Insular cortex ,Surgical planning ,Sensory Systems ,Neurology ,Physiology (medical) ,Anesthesia ,medicine ,Epilepsy surgery ,Ictal ,Neurology (clinical) ,Primary motor cortex ,Motor Deficit ,Psychology - Abstract
Objective To assess whether available algorithms of quantitative EEG (qEEG) could practically help in localizing epileptogenic zone (EZ) and modify surgical planning in patients with focal intractable epilepsy. Methods We will present a case report of a 7-year-old boy with catastrophic epilepsy caused by focal cortical dysplasia located in the operculo-insular region of the right hemisphere. Due to the challenging localization of the presumed EZ, uncertain surgical borders and expected significant risks of the resection, the patient was stereotactically implanted with oblique depth electrodes. Intracranial EEG (iEEG) signal was analyzed using different qEEG methods. Our originally developed interictal epileptiform discharges (IED) detecting algorithm, which also extracts repetitive propagation patterns, was applied to localize sources of IED. We also used own network connectivity algorithm to analyze ictal (seizure) iEEG activity in detail. Employing results of qEEG analyses, 2D and 3D dynamic reconstructions of both interictal and ictal iEEG epileptiform changes were created and used to guide surgical approach. Results Both qEEG algorithms clearly proved the EZ localization in the dorso-caudal insular cortex of the right hemisphere and demonstrated sparing of initially suspected frontal opercular area. The dorso-caudal insular cortex generated 89% of IED; remaining 11% IED originated from the primary motor cortex. Surgical approach was adjusted to this qEEG-based hypothesis. Oblique depth electrodes were preserved intraoperatively to help precise targeting of the lesion. Continuous intraoperative motor-evoked potential monitoring was used to preserve motor functions. The boy has been followed for more than one year postoperatively. He is seizure-free with no motor deficit; with normal cognitive functions. Conclusions The case report demonstrates that currently available qEEG methods could help in guiding resective epilepsy surgery in complicated patients indicated for iEEG studies. We suggest our approach could increase patients’ chance to obtain seizure-free outcomes without new deficits and thus ultimately improve their quality of life. Supported by MH CZ–DRO, University Hospital Motol, Prague, Czech Republic 00064203 and IGA NT/11460-4.
- Published
- 2015
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47. Trends and outcomes for non-elective neurosurgical procedures in Central Europe during the COVID-19 pandemic
- Author
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Lukas Grassner, Ondra Petr, Freda M. Warner, Michaela Dedeciusova, Andrea Maria Mathis, Daniel Pinggera, Sina Gsellmann, Laura C. Meiners, Sascha Freigang, Michael Mokry, Alexandra Resch, Thomas Kretschmer, Tobias Rossmann, Francisco Ruiz Navarro, Andreas Gruber, Mathias Spendel, Peter A. Winkler, Franz Marhold, Camillo Sherif, Jonathan P. Wais, Karl Rössler, Wolfgang Pfisterer, Manfred Mühlbauer, Felipe A. Trivik-Barrientos, Sebastian Rath, Richard Voldrich, Lukas Krska, Radim Lipina, Martin Kerekanic, Jiri Fiedler, Petr Kasik, Vladimir Priban, Michal Tichy, Petr Krupa, Tomas Cesak, Robert Kroupa, Andrej Callo, Pavel Haninec, Daniel Pohlodek, David Krahulik, Alena Sejkorova, Martin Sames, Josef Dvorak, Petr Suchomel, Robert Tomas, Jan Klener, Vilem Juran, Martin Smrcka, Petr Linzer, Miroslav Kaiser, Dusan Hrabovsky, Radim Jancalek, Vincens Kälin, Oliver Bozinov, Cedric Niggli, Carlo Serra, Ramona Guatta, Dominique E. Kuhlen, Stefan Wanderer, Serge Marbacher, Alexandre Lavé, Karl Schaller, Clarinde Esculier, Andreas Raabe, John L. K. Kramer, Claudius Thomé, and David Netuka
- Subjects
Medicine ,Science - Abstract
Abstract The world currently faces the novel severe acute respiratory syndrome coronavirus 2 pandemic. Little is known about the effects of a pandemic on non-elective neurosurgical practices, which have continued under modified conditions to reduce the spread of COVID-19. This knowledge might be critical for the ongoing second coronavirus wave and potential restrictions on health care. We aimed to determine the incidence and 30-day mortality rate of various non-elective neurosurgical procedures during the COVID-19 pandemic. A retrospective, multi-centre observational cohort study among neurosurgical centres within Austria, the Czech Republic, and Switzerland was performed. Incidence of neurosurgical emergencies and related 30-day mortality rates were determined for a period reflecting the peak pandemic of the first wave in all participating countries (i.e. March 16th–April 15th, 2020), and compared to the same period in prior years (2017, 2018, and 2019). A total of 4,752 emergency neurosurgical cases were reviewed over a 4-year period. In 2020, during the COVID-19 pandemic, there was a general decline in the incidence of non-elective neurosurgical cases, which was driven by a reduced number of traumatic brain injuries, spine conditions, and chronic subdural hematomas. Thirty-day mortality did not significantly increase overall or for any of the conditions examined during the peak of the pandemic. The neurosurgical community in these three European countries observed a decrease in the incidence of some neurosurgical emergencies with 30-day mortality rates comparable to previous years (2017–2019). Lower incidence of neurosurgical cases is likely related to restrictions placed on mobility within countries, but may also involve delayed patient presentation.
- Published
- 2021
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48. Treatment of Vagus Nerve Stimulator Pocket Infection without Removal of the Hardware
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Martin BLAHA and Michal TICHY
- Subjects
biofilms ,epilepsy ,epilepsy surgery ,infection ,rifampicin ,vagus nerve stimulation ,Neurology. Diseases of the nervous system ,RC346-429 ,Medicine - Abstract
The management of postoperative pocket infections after vagus nerve stimulator implantation is challenging. Most patients present within four weeks after the implantation of the device and Staphylococcus aureus is the most common infecting agent. Standard medical practice involves the complete hardware removal and antibiotics to achieve long-term cure, with the subsequent reimplantation of the device. Attempts to treat these infections without the removal of the hardware led to high infection recurrence rates because of the formation of staphylococcal biofilms on the device. We present a case of vagus nerve stimulator infection treated successfully with a single surgical debridement of the infected wound and six weeks of antibiotic treatment, but without removing the hardware.
- Published
- 2021
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49. Life-saving epilepsy surgery for status epilepticus caused by cortical dysplasia
- Author
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Pavel, Krsek, Michal, Tichý, Tomás, Belsan, Josef, Zámecník, Lukás, Paulas, Ludvika, Faladová, Premysl, Jiruska, Alice, Maulisová, and Vladimír, Komárek
- Subjects
Cerebral Cortex ,Neurons ,Salvage Therapy ,Status Epilepticus ,Parietal Lobe ,Infant, Newborn ,Humans ,Electroencephalography ,Female - Abstract
A uniquely successful neurosurgical intervention in a four-month-old child suffering from status epilepticus (SE) caused by focal cortical dysplasia is reported. Seizures appeared at postnatal day 10 and culminated as medically intractable focal motor SE three months later. The first MRI scan at postnatal week 2 was inconclusive; electroclinical features typical of malformations of cortical development led to the repetition of MRI at the age of 3 months that confirmed the correct diagnosis. Since all medical trials including thiopental anaesthesia have been unsuccessful in treatment of SE, urgent resection of the right frontal and parietal lobes was performed at 4 months of age. One month later, the child had become seizure-free and her psychomotor development is proceeding well. Histopathological analysis of the resected brain tissue revealed abnormalities typical of the Taylor's type of focal cortical dysplasia. The aim of the report is to encourage considering surgery in selected patients suffering from medically intractable SE early in life.
- Published
- 2002
50. An immunotherapy effect analysis in Rasmussen encephalitis
- Author
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Zuzana Liba, Martina Vaskova, Josef Zamecnik, Jana Kayserova, Hana Nohejlova, Matyas Ebel, Jan Sanda, Gonzalo Alonso Ramos-Rivera, Klara Brozova, Petr Liby, Michal Tichy, and Pavel Krsek
- Subjects
Rasmussen encephalitis ,Immunotherapy effect ,Chemokines ,Cytokines ,Lymphocyte subpopulations ,Alemtuzumab ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Immune-mediated mechanisms substantially contribute to the Rasmussen encephalitis (RE) pathology, but for unknown reasons, immunotherapy is generally ineffective in patients who have already developed intractable epilepsy; overall laboratory data regarding the effect of immunotherapy on patients with RE are limited. We analyzed multiple samples from seven differently treated children with RE and evaluated the effects of immunotherapies on neuroinflammation. Immunotherapy was introduced to all patients at the time of intractable epilepsy and they all had to undergo hemispherothomy. Methods Immunohistochemistry, flow cytometry, Luminex multiplex bead and enzyme-linked immunosorbent assay techniques were combined to determine: 1) inflammatory changes and lymphocyte subpopulations in 45 brain tissues; 2) lymphocyte subpopulations and the levels of 12 chemokines/cytokines in 24 cerebrospinal fluid (CSF) samples and 30 blood samples; and 3) the dynamics of these parameters in four RE patients from whom multiple samples were collected. Results Sustained T cell-targeted therapy with cyclophosphamide, natalizumab, alemtuzumab, and intrathecal methotrexate (ITMTX), but not with azathioprine, substantially reduced inflammation in brain tissues. Despite the therapy, the distributions of CD8+ T cells and the levels of C-X-C motif ligand (CXCL) 10, CXCL13, and B cell activating factor (BAFF) in patients’ CSF remained increased compared to controls. A therapeutic approach combining alemtuzumab and ITMTX was the most effective in producing simultaneous reductions in histopathological inflammatory findings and in the numbers of activated CD8+ T cells in the brain tissue, as well as in the overall CD8+ T cell population and chemokine/cytokine production in the CSF. Conclusions We provide evidence that various T cell-targeted immunotherapies reduced inflammation in the brains of RE patients. The observation that intractable epilepsy persisted in all of the patients suggests a relative independence of seizure activity on the presence of T cells in the brain later in the disease course. Thus, new therapeutic targets must be identified. CXCL10, CXCL13 and BAFF levels were substantially increased in CSF from all patients and their significance in RE pathology remains to be addressed.
- Published
- 2020
- Full Text
- View/download PDF
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