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Dive into the research topics where Leoš Křen is active.

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Featured researches published by Leoš Křen.


European Journal of Haematology | 2016

Thrombosis in thrombocythemic Ph-myeloproliferations is associated with higher platelet count prior to the event: results of analyses of prothrombotic risk factors from a registry of patients treated with anagrelide

Jiří Schwarz; Petra Ovesná; Olga Cerna; Jarmila Kissová; Jacqueline Maaloufová; Yvona Brychtová; Michael Doubek; Libor Červinek; Eduard Cmunt; Petr Dulíček; Vit Campr; Leoš Křen; Miroslav Penka

Controversies still exist regarding definition of the thrombotic risks in Ph‐ (BCR/ABL1‐) myeloproliferative disorders with thrombocythemia (MPD‐T). Platelet counts at diagnosis are currently not taken as a risk factor of thrombosis. In our cohort of 1179 patients with MPD‐T, prospectively registered for anagrelide treatment, we found that the median platelet count prior to the thrombotic event was significantly higher than at time points without any ensuing thrombosis (453 vs. 400 × 109/L, P < 0.001), albeit higher platelet counts at diagnosis tended to be connected with fewer thrombotic events (in contrast to WBC counts at diagnosis). The JAK2V617F mutation predicted both arterial and venous events, while age >65 yr, hypertension, diabetes mellitus, smoking, elevated triglyceride and homocysteine levels predicted arterial events only. For venous events, the specific thrombophilic risk factors (factor V ‘Leiden’ and others), antiphospholipid antibodies, and elevated factor VIII levels played a major role. During anagrelide treatment (± aspirin), we documented a decrease in both venous (6.7‐fold) and arterial events (1.8‐fold), while bleeding (mostly minor events) increased twofold compared to history. Our results suggest that keeping platelet counts at low levels may be a meaningful therapeutic measure to prevent thrombosis, although their counts at diagnosis lack any prognostic value.


The Cardiology | 2009

Intracoronary Delivery of Bone Marrow Cells to the Acutely Infarcted Myocardium

Jaroslav Meluzín; Michal Vlašín; Ladislav Groch; Jiří Mayer; Leoš Křen; Petr Raušer; Boris Tichý; Ivan Horňáček; Jan Sitar; Stanislav Palša; Martin Klabusay; Zdeněk Kořístek; Michael Doubek; Šárka Pospíšilová; L. Lexmaulová; Ladislav Dušek

Objectives: Intracoronary cell transplantation during catheter balloon inflations may be associated with adverse events. We studied the effectiveness of an alternative transplantation technique – intracoronary cell infusion. Methods: Fourteen pigs, which had survived acute myocardial infarction, were randomized into 2 treatment groups and 2 controls. Three days after infarction, 12 pigs underwent allogeneic intracoronary mononuclear bone marrow cell transplantation using either the standard technique (short-term cell injections during repeat balloon inflations, technique A, n = 6) or continuous intracoronary cell infusion without balloon inflations (technique B, n = 6). Implanted cells were stained with fluorescent dye. After transplantation, the pigs were euthanized and myocardial samples were analyzed by fluorescent microscopy. Results: The mean numbers of fluorescently labeled bone marrow cells in the infarction border zone, in the infarction mid-area and in the center of myocardial infarction were 84, 72 and 55 using technique A, and 29, 57 and 46 using technique B, respectively. The mean cell retention in the infarction border zone of 84 cells for technique A and 29 cells for technique B differed significantly (p = 0.034, two-tailed t test). Conclusion: The continuous intracoronary cell infusion technique is a less efficient cell delivery technique as compared with the standard technique using repeat intracoronary balloon inflations.


Clinical Nuclear Medicine | 2014

Upsampling from aorta and aortic branches: PET/CT hybrid imaging identified 18F-FDG hypermetabolism in inflamed temporal and occipital arteries.

Zdeněk Řehák; Petr Szturz; Leoš Křen; Zdeněk Fojtík; Jaroslav Staníček

Temporal arteries are typically below detectable levels of PET scanners, which repeatedly showed to be limiting in finding increased F-FDG accumulation even in histologically proven cases of giant cell arteritis. In 2010, Gaemperli and coworkers showed metabolic active inflammation in temporal arteries in an experimental study using PET with [C]-PK11195 combined with CT angiography. Herein, we present the case where an increased accumulation of routinely used tracer F-FDG can be identified directly in temporal and occipital arteries and even in smaller branches using a common hybrid PET/CT scanner if a brain acquisition protocol is applied.


Leukemia | 2008

The WHO 2008 classification of Ph-myeloproliferative disorders: statement of the Czech MPD Working Group

Jiří Schwarz; Miroslav Penka; Karel Indrak; D Pospís̆ilová; R Pytlík; P Dulíc̆ek; Michael Doubek; Leoš Křen; Vit Campr

The WHO 2008 classification of Ph-myeloproliferative disorders: statement of the Czech MPD Working Group


Leukemia & Lymphoma | 2012

Cytokine analysis in a patient with relapsing Kikuchi - Fujimoto disease

Petr Szturz; Zdeněk Adam; Jana Chovancová; Olga Stehlíková; Martin Klabusay; Josef Feit; Leoš Křen; Zdeněk Fojtík; Marta Krejčí; Luděk Pour; Roman Hájek; Jiří Mayer

In 2006, a 26-year-old woman presented with tender cervical and retroauricular lymphadenopathy accompanied by fever, lower limb paraparesis, skin rash and generalized myalgia. Her past medical history was unremarkable. Full blood count and renal and hepatic profi les were within normal ranges, with the exception of mild lactate dehydrogenase elevation (237 U/L). Microbiological and radiological screening revealed no infectious etiology, and immunological fi ndings were negative or normal. In contrast to increased C-reactive protein levels (140 mg/L), the serum procalcitonin level was low. Brain magnetic resonance and lumbar puncture showed no pathology.


Journal of Cancer Research & Therapy | 2017

An anaplastic cardiac large cell lymphoma: A case report and analysis of cardiac involvement in newly diagnosed non-Hodgkin’s lymphoma from the Czech Lymphoma Study Group (CLSG) database

Cosimo Lobello; Andrea Janíková; Leoš Křen; Markéta Hermanová; Andrea Šprláková-Puková; Jan Krejčí; Šárka Pospíšilová; Robert Pytlik; Michaela Hamouzova; David Belada; Vit Prochazka; Juraj Duras; Heidi Mocikova; Marek Trněný

We report a rare case of anaplastic large cell ALK+ lymphoma (ALCL) with initial asymptomatic cardiac involvement. A 59-year-old male with infiltration of the right ventricular wall underwent standard combined chemotherapy (CHOP) and achieved remission without significant cardiac impairment. Additionally, we report the actual incidence of cardiac lymphoma in newly diagnosed non-Hodgkin Lymphomas (NHLs). In total, 16 patients with cardiac lymphoma were found (0.1% NHLs) in the Czech Lymphoma Study Group database. DLBCL was the most frequent histology subtype (50%), and ALCL was identified in 12.5% of cases. At initial diagnosis, the median age was 55.5 (range 21-74) years and 59% were men. None of the 16 patients with cardiac involvement had isolated heart lymphoma. The response to first-line therapy was 79% in 14/16 evaluable patients. The median progression-free survival and overall survival were nearly the same -approximately 3.5 years (range; 0.05-16.7ys), while the median follow up was 4 years.


Neoplasma | 2010

MicroRNA-181 family predicts response to concomitant chemoradiotherapy with temozolomide in glioblastoma patients

Ondřej Slabý; Roman Lakomý; Pavel Fadrus; Roman Hrstka; Leoš Křen; Eva Lžičařová; Martin Smrčka; Marek Svoboda; H. Doležalová; Jana Nováková; Dalibor Valík; Rostislav Vyzula; Jaroslav Michálek


Acta Veterinaria Brno | 2007

Prevention of Bone Bridge Formation Using Transplantation of the Autogenous Mesenchymal Stem Cells to Physeal Defects: An Experimental Study in Rabbits

Ladislav Plánka; Alois Nečas; Petr Gál; H. Kecová; Eva Filova; Leoš Křen; Petr Krupa


Physiological Research | 2010

Quality of Newly Formed Cartilaginous Tissue in Defects of Articular Surface after Transplantation of Mesenchymal Stem Cells in a Composite Scaffold Based on Collagen I with Chitosan Micro- and Nanofibres

Alois Nečas; Ladislav Plánka; Robert Srnec; Michal Crha; Jana Hlučilová; Jiří Klíma; David Starý; Leoš Křen; Evžen Amler; Lucy Vojtová; Josef Jančář; Petr Gál


Acta Veterinaria Brno | 2007

Chondrocytic Potential of Allogenic Mesenchymal Stem Cells Transplanted without Immunosuppression to Regenerate Physeal Defect in Rabbits

Petr Gál; Alois Nečas; Ladislav Plánka; H. Kecová; Leoš Křen; Petr Krupa; Jana Hlučilová; D. Usvald

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Ondřej Slabý

Central European Institute of Technology

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