Diagnosis and treatment of juvenile myelomonocytic leukemia in Slovak Republic: novel approaches.

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.

The effect of ethylene oxide sterilization on electrospun vascular grafts made from biodegradable polyesters.

The study describes the detailed examination of the effect of ethylene oxide sterilization on electrospun scaffolds constructed from biodegradable polyesters. Different fibrous layers fabricated from polycaprolactone (PCL) and a copolymer consisting of polylactide and polycaprolactone (PLCL) were investigated for the determination of their mechanical properties, degradation rates and interaction with fibroblasts. It was discovered that the sterilization procedure influenced the mechanical properties of the electrospun PLCL copolymer scaffold to the greatest extent. No effect of ethylene oxide sterilization on degradation behavior was observed. However, a delayed fibroblast proliferation rate was noticed with concern to the ethylene oxide sterilized samples compared to the ethanol sterilization of the materials.

Avascular necrosis of bone in childhood cancer patients: a possible role of genetic susceptibility.

With the increasing number of paediatric cancer patients and with their prolonged survival, the evidence of a number of serious complications induced by anticancer therapy is rising. Osteonecrosis (ON) of bone is one of these treatment-related effects with a multifactorial pathogenesis. In the past few years, several polymorphisms of candidate genes with possible role in development of this disorder were studied.We summarized potential risk factors leading to increased susceptibility to osteonecrosis of bone development in cancer patients during childhood and to present current knowledge in the field of genetic aspects of this condition (Ref. 86).

Protothecal peritonitis in child after bone marrow transplantation: case report and literature review of paediatric cases.

The case presented here illustrates a protothecal infection caused by Prototheca wickerhamii in a paediatric haematopoietic stem cell recipient followed by a review of the literature of all 13 paediatric cases published since 1980. Protothecosis is a rare disease caused by algae, not described in this setting before. Infection was proven additionally post-mortem from peritoneal dialysis fluid. Even though no death of a paediatric patient due to this infection has been reported and the mortality rate associated with protothecosis is low, our patient died from multiorgan failure as a result of numerous post-transplant complications and a strain of cultivated alga that was highly resistant to antifungal agents. Prototheca spp. show various susceptibility profiles, and there is no direct correlation between in vitro activity and clinical response. There are different treatment regimens described but there are no clear published guidelines of specific therapy of protothecosis. Paediatric cases were successfully treated mostly with amphotericin B and azoles. As the number of immunocompromised patients increases, it is necessary to think more about unusual pathogens such as Prototheca.

[Comparison of reactive oxygen species production in neat semen and washed spermatozoa]. / Porovnání produkce reaktivních kyslíkových cástic v nativním ejakulátu a v suspenzi spermií.

OBJECTIVE: To determine Reactive Oxygen Species (ROS) production in neat semen and spermatozoa suspension using chemiluminescence and to examine correlation between both methods. SUBJECT: Prospective laboratory study. SETTING: Department of Obstetric and Gynecology, University Hospital, Olomouc. METHODS: The study included fertile volunteers (FV, n = 17), men from infertile couples (NM, n = 19) and men with idiopathic infertility (NMI, n = 15). ROS levels were determined by the same method in neat and washed semen samples. RESULTS: The ROS production in neat semen was lower than that in spermatozoa suspension. There was no significant diference in ROS production between volunteers and males from infertile couples. There was a significant correlation between log ROS in neat semen and in spermatozoa suspension in studied groups (FV r = 0.85, p = 1.5 x 10(-5); NM r = 0.76, p < 2 x 10(-4); NMI r = 0.75, p < 1.5 x 10(-3)). CONCLUSIONS: Measurement of ROS in neat semen is simpler, faster and better reflecting the actual level of oxidative stress than the same measurement in spermatozoa suspension. The implementation of this method can complement the algorithm of diagnostics and treatment of male infertility and be helpful in selection of patients for antioxidant or antibiotic treatment.

Evaluation of chromatin integrity of motile bovine spermatozoa capacitated in vitro.

The efficiency of in vitro embryo production is highly variable amongst individual sires in cattle. To eliminate that this variability is not caused by sperm chromatin damage caused by separation or capacitacion, chromatin integrity was evaluated. Seventeen of AI bulls with good NRRs but variable embryo production efficiency were used. For each bull, motile spermatozoa were separated on a Percoll gradient, resuspended in IVF-TALP medium and capacitated with or incubated without heparin for 6 h. Samples before and after separation and after 3-h and 6-h capacitacion or incubation were evaluated by the Sperm Chromatin Structure Assay (SCSA) and the proportion of sperm with intact chromatin structure was calculated. Based on changes in the non-DFI-sperm proportion, the sires were categorized as DNA-unstable (DNA-us), DNA-stable (DNA-s) and DNA-most stable (DNA-ms) bulls (n=3, n=5 and n=9, respectively). In DNA-us bulls, separation produced a significant increase of the mean non-DFI-sperm proportion (p

Early oocyte penetration can predict the efficiency of bovine embryo production in vitro.

The aim of this work was to characterize oocyte fertilization and embryo cleavage in nine AI bulls to find parameters suitable for prediction of in vitro fertility. According to the d8 blastocysts rate, they were categorized as high, medium and low productive (HP, MP and LP, mean: 25.4, 21.0 and 13.6% respectively) bulls. For these categories, oocyte penetration and fertilization efficiency were assessed at 6 and 18 hours post insemination (hpi), respectively. Some presumptive zygotes were cultured and cleaved and fast-cleaved embryo rates were checked at 44 hpi. The penetration rate was significantly higher for HP bulls than for MP and LP bulls (67.9 versus 50.3 and 33.1%; p<0.01). The syngamy rate was significantly higher for HP bulls than for MP and LP bulls (21.4 versus 10.2 and 5.7%; p<0.05). Conversely, no significant differences in fertilization rates were found among HP, MP and LP bulls. The cleavage rate was significantly higher for HP than LP bulls (82.4 versus 74.4%; p<0.01). The fast cleavage rate was significantly higher for both HP and MP bulls, as compared with LP bulls (82.1 and 84.7 versus 73.5%; p<0.01). A strong correlation was found between blastocyst production and penetration (r=0.803), syngamy (r=0.826), cleavage (r=0.635) and fast cleavage (r=0.709). In conclusion, all the evaluated parameters showed a predictive value, the most significant being early penetration and syngamy.

[Oxidative stress in diagnosis and treatment of idiopathic male infertility]. / Oxidacní stres v diagnostice a lécbe idiopatické muzské neplodnosti.

OBJECTIVE: To summarize available data concerning reactive oxygen species in sperm physiology and male infertility. DESIGN: Review article. SETTING: Dept. of Obstetrics and Gynecology, Faculty of Medicine and Dentistry, Palacky University and University Hospital Olomouc. METHODS: Compilation of published data from scientific literature. CONCLUSIONS: The article describes the importance of reactive oxygen species and their role in male reproductive health.

Establishing the method of chimerism monitoring after allogeneic stem cell transplantation using multiplex polymerase chain reaction amplification of short tandem repeat markers and Amelogenin.

We describe the implementation, optimization, sensitivity determination and first clinical results of polymerase chain reaction (PCR) amplification of polymorphic short tandem repeat (STR) markers and Amelogenin locus coupled with fluorescent detection and capillary electrophoresis in chimerism monitoring of patients transplanted at three different transplant centers using a commercially available multiplex microsatellite assay. The chimerism analysis was performed with genomic DNA extracted from unselected peripheral blood leukocytes of one hundred pediatric and adult patients, who underwent allogeneic stem cell transplantation (SCT) from human leukocyte antigen (HLA) matched or one antigen mismatched related or unrelated donors for malignant (70 patients) and non-malignant (30 patients) diseases. Tested were 79 donor recipient pairs for 15 STR systems and identified an informative marker in all but one of them (98,7%), using 6 selected systems out of these fifteen, that appeared highly informative in our patients population. In 21 sex-mismatched donor recipient pairs we used the Amelogenin locus to distinguish the X and Y chromosome. In sixty-three out of these 100 patients chimerism was regularly analyzed from blood samples taken at various time points after SCT with the median follow up of 17 months. Complete chimerism (CC), maintained over the whole follow-up period, was detected in 24 (38, 1%), stable and decreasing mixed chimerism (MC) in 28 (44, 4%) and increasing MC in 11 patients (17, 5%). Patients with CC, stable and decreasing MC showed a significantly better (p 0,005) overall survival rate (0, 81), compared to those with increasing MC (0, 24). These results demonstrate that STR-based chimerism monitoring with sensitivity above 1% and high informativity (98, 7% of donor recipient pairs) is necessary in establishing the origin of engrafted cells after an allogeneic SCT, in detecting graft rejection and that it may contribute in identifying patients with imminent leukemia relapse.

Efficiency and kinetics of the in vitro fertilization process in bovine oocytes with different meiotic competence.

The aim of the study was to investigate the efficiency and kinetics of fertilization in oocytes with different meiotic competence, as defined by the phase of the follicular wave and follicle size. Oocytes were recovered from cows with synchronized estrus cycles, slaughtered in either the growth (day 3) or the dominant (day 7) phase, separately from large, medium and small follicles. The oocytes were matured and fertilized by a standard protocol. Twenty-four hours after fertilization, the oocytes were denuded from cumulus cells, fixed and stained with bisbensimid Hoechst-PBS. Fertilization was more efficient and the first cleavage was accelerated in growth phase-derived oocytes, as shown by significantly higher (p < or = 0.01) proportions of both normally fertilized and cleaved oocytes (68.8 and 25.1%), in comparison with dominant phase-derived oocytes (44.2 and 10.3%). In the growth-phase derived oocytes, proportions of normally fertilized and cleaved oocytes were significantly higher (p < or = 0.01) in oocytes from large (100.0 and 36.4%) and medium (83.3 and 36.5%) follicles than in those from small (54.8 and 14.6%) follicles. The dominant phase-derived oocytes showed higher proportions of normally fertilized and cleaved oocytes in the populations recovered from small (51.5 and 10.0%) and medium (43.1 and 12.0%) follicles than in those from large (25.0 and 0%) follicles; however, the differences were not significant. It can be concluded that: (i) efficiency and kinetics of fertilization differ in relation to oocyte's meiotic competence; (ii) improved development of embryos from oocytes with greater meiotic competence is associated with a more effective fertilization process.

Effects of cyanobacterial biomass on the Japanese quail.

Mortality of wild aquatic birds has recently been attributed to cyanobacterial toxins. Despite this, no experimental studies on the effects of defined doses of microcystins administered orally to birds exist. In this experiment, four groups of male Japanese quails daily ingesting 10ml of Microcystis biomass containing 0.045, 0.459, 4.605 or 46.044mug of microcystins, respectively, for 10 and 30 days, showed no mortality. Histopathological hepatic changes in birds after the biomass exposure included cloudy swelling of hepatocytes, vacuolar dystrophy, steatosis and hyperplasia of lymphatic centres. On subcellular level, shrunken nuclei of hepatocytes containing ring-like nucleoli, cristolysis within mitochondria and vacuoles with pseudomyelin structures were present. Vacuolar degeneration of the testicular germinative epithelium was found in two exposed males. Statistically significant differences in biochemical parameters were on day 10 of exposure only. They comprised increased activities of lactate dehydrogenase and a drop in blood glucose in birds receiving the highest dose of the biomass. Principal component analysis revealed a pattern of responses in biochemical parameters on day 10 that clearly separated the two greatest exposure groups from the controls and lower exposures. The results indicate that diagnosis of microcystin intoxication solely based on clinical biochemical and haematological parameters is hardly possible in birds.

Embryos produced in vitro from bulls carrying 16;20 and 1;29 Robertsonian translocations: efficiency and kinetics of oocyte fertilization and embryo development.

The present experiments were designed to study the effects of Robertsonian translocations on the efficiency and kinetics of in vitro fertilization and early and advanced embryo development. Spermatozoa from bulls with rob(16;20), rob(1;29) and normal karyotype (A, B and C, respectively) were used. Oocytes were matured, fertilized and cultured by the standard protocol described previously. Twenty-four hours after fertilization, adequate numbers of oocytes were fixed, stained and examined. The development of embryos was evaluated on days 2 (D2), 7 (D7) and 8 (D8) after fertilization. The rate of normally fertilized oocytes was significantly lower (p < or = 0.01) for bull A than for bulls B and C. However, no significant differences in the kinetics of fertilization were found between bulls A, B and C. The D2 cleavage rate of embryos was significantly lower (p < or = 0.01) for bull A than for bulls B and C. Both D7 and D8 blastocyst rates for bull A or bull B were significantly lower (p < or = 0.01 or p < or = 0.05) than those for bull C. The percentages of both D7 advanced blastocysts and D8 expanded blastocysts were significantly lower (p < or = 0.01) for bulls A and B than for bull C. In conclusion, for rob(16;20), the efficiency of fertilization was strongly reduced; it resulted in low early and advanced embryo development. On the other hand, for the rob(1;29), neither fertilization nor early embryo development were affected and only advanced embryo development was decreased. But for both translocations, blastocyst formation was significantly delayed.

A significance of additional chromosomal aberrations and other variables on post transplantation outcome of patients with CML.

Chronic myeloic leukemia (CML) is a malignant disease of hematopoietic stem cell characterized by the bcr/abl gene rearrangement. Allogeneic transplantation of stem cells (SCT) is a routinely used treatment method of patients with this diagnosis and remains the only curative mode of treatment. From January 1990 to December 2002, 78 patients with CML underwent allogeneic transplantation and were examined at the Department of Genetics in the National Cancer Institute in Bratislava. Using conventional cytogenetic and FISH 6 patients (7.7%) showed additional chromosomal changes before SCT. These patients had statistically worse post transplantation prognosis compared to the patients without additional changes before SCT (mean survival in month+/-standard error (58.08 (+/-6.70) vs. 5.17 (+/-0.98), p-value=0.001), patient mortality (67% vs. 31%)). In addition five other variables were evaluated for transplant outcome, namely, patient's age at the time of transplantation, sibling or non-sibling donor, higher than 1st chronic phase CML, time from diagnosis to transplantation and sex of donor and recipient. Only the comparison of HLA-identical sibling transplantation to unrelated donor transplantation was statistically significant (mean survival in month- 56.6 (+/-7.2) vs. 13 (+/-0.0), patient mortality 31% vs. 67%).

Allogeneic peripheral blood stem cell transplantations in children--a single center experience.

We analyzed 30 peripheral blood stem cell transplantations (PBSCT) from 25 human leukocyte antigen (HLA) matched sibling donors (MSD) and 4 HLA-matched unrelated donors (MUD) in 29 patients, done between November 1996 and March 2003. Patients aged 3 to 17 years underwent allogeneic PBSCT for malignant (16 patients) and non-malignant (13 patients) diseases. Sibling donors aged 3 to 23 years were given granulocyte colony-stimulating factor (G-CSF) 5-10 microg/kg/day for 4 to 5 days. All but one of the 29 donors underwent one single leukapheresis for stem cell collection. The patients received a median of 4.2 x 10(6) CD34+ cells/kg of body weight, they all engrafted after a median of 13.5 days (range 10-25 days). Acute graft-versus-host disease (GVHD) grade II to IV developed in 11 of 26 MSD transplants and in all 4 patients after MUD PBSCT. Eleven of 27 evaluable patients experienced chronic GVHD. After a median follow-up of 662 days, 20 out of 29 patients (69%) are alive, three of them need systemic immunosuppression for chronic GVHD. Six patients experienced relapse of their underlying malignant disease, one of them still alive in complete remission. Two patients died of grade IV acute GVHD and two others due to an opportunistic infection. Based upon our experience, PBSCT is a feasible and safe method for both pediatric donors and patients. It is associated with rapid engraftment, no greater incidence of acute but a higher incidence of chronic GVHD as compared to bone marrow transplantation (BMT) and therefore suitable mainly for children suffering from malignant diseases.

[Autoimmune hemolytic anemia and chronic giant cell hepatitis]. / Autoimúnna hemolytická anémia a chronická obrovskobunková hepatitída.

The authors describe a case report of a six months old boy with autoimmune hemolytic anemia and giant cell hepatitis. This is a very rare syndrome in infancy. After eleven months of intensive immunosuppressive treatment (glucocorticoids, cyclosporin A, azathioprin, intravenous immunoglobulins, cyclophosphamid) no improvement of hemolysis was observed and therefore splenectomy was indicated. 1 year after the treatment was finished the patient is in good general condition and his hematologic and biochemical parameters are physiological.

Matrix effects in PIXE analysis of aerosols and ashes.

A comparison of instrumental neutron activation analysis (INAA) and proton-induced X-ray emission (PIXE) results for size-fractionated atmospheric aerosols ("coarse" and "fine" fractions with an equivalent aerodynamic diameter of 2-10 microns and < 2 microns, respectively, or the PM10 fraction) showed that PIXE yielded significantly lower results for the PM10 and coarse fractions, especially for elements with a low Z resulting from a particle size effect. Somewhat lower PIXE results were also obtained for the fine fraction of atmospheric aerosols. A correction is also needed for irregularly shaped deposits of combustion aerosols collected by a cascade impactor in 11 size fractions ranging from 0.016 to 14.3 microns, as well as for thick samples of fly and bottom ashes. An equivalent layer thickness (ELT) model is proposed to correct the matrix effects in PIXE. The approaches for the calculation of ELT using a comparison of PIXE and INAA results or by comparing PIXE results obtained using two different incident proton beam energies (1.31 and 2.35 MeV) are described. The correction for the ash pellets and irregular deposits are also discussed.

Localisation and distance between ABL and BCR genes in interphase nuclei of bone marrow cells of control donors and patients with chronic myeloid leukaemia.

Quantitative measurements of the nuclear localisation of the ABL and BCR genes and the distance between them were performed in randomly oriented bone marrow cells of control donors and patients with chronic myeloid leukaemia (CML). Most ABL and BCR genes (75%) are located at a distance of 20-65% of the local radius from the nuclear centre to the nuclear membrane. A chimeric BCR-ABL gene located on a derivative chromosome 22 resulting from t(9;22)(q34;q11) [the so-called Philadelphia (Ph) chromosome] as well as the intact ABL and BCR genes of patients suffering from chronic myeloid leukaemia are also located mostly in this region, which has a mean thickness of 2 microns in bone marrow cells. We have not found any significant differences in the location of the two genes in the G1 and G2 phases of the cell cycle, nor between bone marrow cells and stimulated lymphocytes. Irradiation of lymphocytes with a dose of 5 Gy of gamma-rays results in a shift of both genes to the central region of the nucleus (0-20% of the radius distant from the nuclear centre) in about 15% of the cells. The minimum distance between one ABL and one BCR gene is less than 1 micron in 47.5% of bone marrow cells of control donors. Such a small distance is found between homologous ABL and between homologous BCR genes in only 8.1% and 8.4% of cells, respectively. It is possible that the relative closeness of nonhomologous ABL and BCR genes in interphase nuclei of bone marrow cells could facilitate translocation between these genes. In 16.4% of bone marrow cells one ABL and one BCR gene are juxtaposed (the distance between them varies from 0-0.5 micron) and simulate the Ph chromosome. This juxtaposition is the result of the projection of two genes located one above another into a plane, as follows from the probability calculation.

[An unusual cause of respiratory failure. Bronchobiliary fistula]. / Neobvyklá pricina respiracného zlyhávania. Bronchobiliárna fistula.

The authors describe the treatment of a patient with an inborn bronchobiliary fistula. The ex post finding that the fistula had two insertions in the bronchus called in the final stage for a combined thoraco-abdominal approach with resection of the right lower pulmonary lobe with ligature of the fistula beneath the diaphragm. Although inborn bronchobiliary fistulae are very rare, they must be considered in the differential diagnosis of causes of chronic respiratory distress syndrome in children. Early diagnosis and adequate surgical treatment make it possible to prevent serious chronic cardiorespiratory disease.