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Acute lymphoblastic leukemia (ALL) belongs to a genetically heterogeneous disease associated with a wide range of chromosomal and molecular changes. Determining these changes at the time of diagnosis can help the therapeutic decision, and contributes to the prediction of patients' clinical outcomes. A part of B-ALL (B-other) lacks cytogenetic abnormalities with clinical relevance for prognosis. Our first goal was to retrospectively review genetic results of patients from 2013-2017 and identify number of B-other patients in Slovak population. The second goal was to implement single nucleotide polymorphism (SNP) array analysis to improve the diagnosis and risk stratification. In this study we reviewed 133 B-ALL patients. We found that nearly 40% of them (52 cases) belonged to the B-other ALL group. Eighteen B-other ALL patients were subjected to the analysis using SNP-array. Overall, we identified 126 cytogenomic changes and in 4 patients the SNP array revealed clinically relevant markers of adverse prognosis and high relapse risk. Integrating identified genetic changes into clinical practice can bring improvement of prognosis assessment for children with ALL in Slovakia.

Juvenile myelomonocytic leukemia (JMML) is a rare, aggressive clonal myeloproliferative disorder of infancy and early childhood caused by oncogenic mutations in genes involved in the Ras pathway. Long-term survival has only been achieved with hematopoietic stem cell transplantation (HSCT), being able to cure more than 50% patients. To manage the disease before HSCT remains an important issue with constant searching for optimal treatment modalities. According to several retrospective analyses, azacitidine (AZA) induced clinical and molecular responses in patients with relapsed JMML pre-transplant and post-transplant, suggesting its use as a promising "bridging" therapy before HSCT. In this paper we report our first consecutive cohort of patients with JMML treated at our institution as well as our experience with the diagnosis, novel treatment and management of these patients before the HSCT. We present 6 patients with JMML, harboring different somatic mutations (PTPN11 and NRAS), with distinct clinical features; 3 of them had been treated with AZA 75 mg/m2 i.v. on days 1 to 7 of a 28-day cycle before the HSCT. Response to therapy was evaluated after each cycle in accordance with the International response criteria. One patient had a progression of splenomegaly during the treatment and after three cycles he was urgently transplanted. At the present, he is remaining in complete remission 3 years after HSCT. Two patients showed impressive response following the first cycle of the therapy with a regression of splenomegaly and monocyte count, normalized leukocytes, platelets and absent blasts in peripheral blood. The treatment was well tolerated with no adverse effect recorded. The clinical activity and favorable toxicity of AZA in JMML provide a rationale for its use as a "bridging" therapy before HSCT. Prospective trials with accompanying translational studies are required to provide further information regarding individual factors that may direct the most appropriate choice of pretransplantation therapy.

Our aim was to analyze event-free (EFS) and overall survival (OS) among children and adolescents with acute lymphoblastic leukemia (ALL) treated with International BFM Intercontinental trial (ALL IC 2002) therapy in the Slovak Republic. In total, 280 children and adolescent age 1 to 18 years were treated with ALL IC BFM 2002 based therapy from 2002 to 2012, which was divided into two periods. During 2002-2007, when patients were actively enrolled in the ALL IC-BFM 2002 trial, and during 2008-2012 when the trial was closed and patients were treated with the same therapy without randomization. Five-year EFS and OS rates were 79% (+/- 2.6%) and 86% (+/- 2.1%), respectively, similar to results obtained in the ALL-BFM 95 trial, which was the basis for ALL IC BFM 2002 therapy. The EFS (p<0.012) and OS (p<0.003) were significantly better than the prior Slovak experience in 1997-2001. Survival is improved in standard and intermediate risk groups, including those age 1 to 6 years, and older; with B-cell or T-cell immunophenotype, and is also excellent for those with good early response. The rate of death in induction, cumulative incidence of death in complete remission and of relapse decreased. However, outcome was suboptimal for patients in the high risk group. Current EFS and OS rates for children and adolescents with ALL in the Slovak Republic resembled those obtained in Western Europe as a result of clinical trial participation, and clinical experience acquired with intensive BFM type treatment.

Changes in the ultrastructure of rat myocardial cells were investigated after withdrawal of therapy with the calcium entry blockers diltiazem, nifedipine, and verapamil. Two hours after the last administration the ultrastructure was without significant changes in comparison to the control group. However the incidence of contracture bands, dehiscence of intercalated discs and lesions of mitochondria observed 30 hours after therapy withdrawal demonstrated serious damage of myocardial tissue. The recorded changes, practically identical with changes associated with the calcium paradox, were the consequence of withdrawal of calcium entry blocker therapy. The reported morphological changes reflected biochemical and functional changes characteristic of the calcium entry blocker withdrawal syndrome.

The influence of cholesterol atherogenic diet on the acid-base balance and electrolyte profile was investigated in rabbit blood and the effect of simultaneous administration of verapamil and nifedipine on the induced changes was evaluated. Cholesterol diet resulted in significant metabolic acidosis, hyperkalemia, and a slight decrease in plasma ionized calcium. On the other hand, longterm treatment with verapamil and nifedipine exhibited their protective effect, with the acid-base status and electrolyte profile maintained within the normal range. The protective effect of verapamil and nifedipine against cholesterol induced acid-base and electrolyte disturbances appears to be associated with their antiatherogenic activity. (Fig. 5, Ref. 10.).

Our previous experiments have suggested that besides the receptor cont and/or sensitivity a decrease of intracellular calcium level significantly participates in the mechanism of beta-blocker withdrawal 'rebound' phenomenon. This suggestion initiated studies in which possible changes in myocardial responsibility to cardioactive drugs were investigated in the condition of withdrawal of treatment with calcium entry blockers. The results showed increased cardiotoxicity of ouabain, aconitine and CaCl2, as well as an increased response of the heart to isoprenaline 24 hours after sudden cessation of treatment with verapamil (2 mg.kg-1 x 12 hours-1), diltiazem (3 mg.kg-1 x 12 hours-1) and nifedipine (0.5 mg.kg-1 x 12 hours-1). These results support the hypothesis of a common mechanism of the withdrawal syndrome of beta-lytics and calcium antagonists involving changes in intra-cellular calcium level. (Tab. 2, Fig. 4, Ref. 33.).

The effect of N-(2-hydroxyethyl)-palmitamide (PEA), an active endogenous compound, which may be useful in preventing virus infections of the respiratory tract, was studied in chicken sarcoma RBA-34 and mouse Rauscher leukemia. The experiments showed that PEA did not influence the induction, development and severity of experimental oncogenic diseases investigated.

The effects of N-(2-hydroxyethyl) palmitamide (PEA) a natural and antitoxic substance on the treatment of RBA rat leukemia were studied. Repeated administration of PEA prolonged substantially survival of leukemic animals in the course of the treatment with cis-diamminedichlor-platinum (cis-Pt(II) in combination with cyclophosphamide, vincristine and methotrexate respectively. The most advantageous combination used was the cis-Pt(II) with methotrexate and PEA administration even improved the treatment results. The long-termed PEA treatment depressed first of all undesirable side effects and enabled to use higher therapeutic dosage of chemotherapeutics and improved the final results.