Biomedical subjects
Publications and source records attributed to P Stránský.
The work provides basic information about what is being understood under the term "statistical analysis of power of test" from the viewpoint of correct use of mathematical statistics in medicine. The detail rules of statistical decision-making are described. Furthermore, the work contains an illustration of power analysis of test application when using unpaired t-test.
The aim of the study was to investigate chosen haemostasis activation markers during electrophysiologic study (EPS) with consequent radiofrequency catheter ablation (RFA). Sixty-three patients were studied prospectively. Indications for EPS and RFA were supraventricular tachycardias with the arrhythmogenic substrate located in the right atrium. Blood samples were drawn 24 hours before the procedure (T -1), at the beginning of the procedure (T0), at the end of EPS (T1), 30 minutes after completion of RFA (T2), and 24 hours after the procedure (T3). To study coagulation, fibrinolytic and platelet activation were measured concentrations of thrombin-antithrombin III (TAT), D-dimers (DD), platelet count and parameters, and circulating platelet aggregates (CPAi). During the EPS and RFA, TAT levels increased from the baseline 5.03 +/- 2.53 microg/l (T -1) to 12.90 +/- 12.83 microg/l at T0 (p < 0.001) to 36.07 +/- 15.59 microg/l at T1 (p < 0.001) and decreased to 28.85 +/- 13.14 microg/l at T2 (p < 0.001). Levels of DD increased from 0.30 +/- 0.20 mg/l at T0 to 0.44 +/- 0.25 mg/l at T1 (p < 0.001) and to 0.87 +/- 0.74 mg/l at T2 (p < 0.001). The number of platelets was significantly decreased (-13.7%) before and during the procedure (T -1 vs. T3; p < 0.001). Marked platelet activation (CPAi 0.62 +/- 0.32) was observed before the procedure opposite to the physiological values (CPAi 1.0 +/- 0.1), without changes during the procedure (CPAi at T2 0.69 +/- 0.23). Our results confirmed activation of several haemostasis parameters during EPS and RFA, and support eligibility of the antithrombotic prevention in patients indicated for EPS and RFA.
The aim of our project was to compare the efficacy of mobilised whole blood versus cryopreserved PBPC (peripheral blood progenitor cells) obtained by leukapheresis in the support of hematopoietic recovery in cyclic intensive chemotherapy. Twenty-nine women with breast carcinoma were treated. The mean age was 46 years. In stage III were 23, in stage IV were 6. They received 6 cycles of epirubicin 150 mg/m2 and cyclophosphamide 1250 mg/m2. In the first cycle, 24 hours after chemotherapy, application of G-CSF 5 microg/kg/day was started, and discontinued when leukaphereses and whole blood collections were done. Leukapheresed progenitors were then divided into 3 aliquots, cryopreserved and reinfused after the 4th, 5th and 6th chemotherapy cycles. Mobilised whole blood was collected on day 14 of the 1st and 2nd cycles and reinfused 24 hours after chemotherapy. The occurrence of grade IV leukopenia was 1.82 times higher with whole blood support and grade IV thrombocytopenia 2.64 times higher than in cycles with cryopreserved PBPC support. This resulted from the fact that in one application the numbers of CD34+ cells and CFU-GM were nearly double in cryoconcentrates. The yields of CD34+ cells in 450 ml of whole blood were 1.8 x 10(6)/kg, which is not sufficient for optimal hemopoietic recovery.
A successful pregnancy is dependent on the development of adequate placental circulation. The abnormalities of placental vasculature may result in a number of gestational pathologies, including fetal loss. The aim of our study was to determine whether women with f V Leiden are at an increased risk of pregnancy loss. For this purpose we assessed three groups of women. In a prospective group we examined 30 females with spontaneous abortions for f V Leiden. In a retrospective group we assessed the frequency of abortions in 80 women (172 pregnancies) with f V Leiden (72 heterozygous, 8 homozygous) from 57 unrelated families. In a control group we evaluated the frequency of abortions in 45 women without f V Leiden. Factor V Leiden was found in 3% of women in the 1st group. Fetal loss occurred in 10% of women in the 2nd group and in 9% in the 3rd group. Factor V Leiden was not found to be a risk factor for fetal loss in our study group.
Thrombocytopenia and following bleeding at the treatment of hematological malignancies is a dangerous complication. The indication of thrombocyte transfusion is the key point for the therapy and proylaxy of bleeding. The all problem is divided into two parts. Evaluation of the risk of bleeding (80% of decision), estimation of the risk of aloimunization and risk of connected with the transfusion (20% decision). For now we are concentrated to the evaluation of the risk of bleeding. In the first stage we are concentrated to statistical evaluation of values to define factors possibly highering the risk of bleeding. Factors were determined with help of two test, GUHA method and using literature. For recognized factors were trained 3 layer neuron nets with a non-linear method pack propagation. After that an application was developed to determine the risk of bleeding for a routine use in clinical practice.
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UNLABELLED: Red cell distribution width (RDW) was examined in 18 patients with hairy cell leukemia (HCL) treated with 2-chlorodeoxyadenosine (2-CdA), in 5 patients treated with Interferon alpha (IFN-alpha) and in 9 patients subjected to splenectomy. Out of 18 patients treated with 2-CdA one patient was excluded of the study because of association of HCL with acquired sideroblastic anemia. In the remaining 17 patients the mean value of RDW before therapy was 18.8% (range 13.5% to 25.0%) and dropped after successful therapy after 6 to 12 months to the mean value of 13.6% (range 11.2% to 17.9%) and after 18 months to 13.4% (range 12.6% to 14.7%) (p = 0.00015 and p = 0.00049 respectively). The hemoglobin level increased from the mean value of 119 g/l (range 99 g/l to 157 g/l) before therapy to the mean value of 145.9 g/l (range 127 g/l to 172 g/l) after 6 to 12 months and after 18 months to 147.8 g/l (range 132 g/l to 168 g/l) (p = 0.000017 and p = 0.00036 respectively). The same trend was observed in the group of patients treated with IFN-alfa. The RDW decreased from the mean value of 21.3% (range 18.8% to 28.7%) to the mean value of 15.3% (range 12.4% to 16.7%), (p = 0.031). The hemoglobin level increased in this group of patients from the mean value of 115 g/l (range 98 g/l to 127 g/l) to the mean value of 136 g/l (range 127 g/l to 146 g/l) (p = 0.031). In 9 patients in complete hematologic remission 34 to 293 months after splenectomy the mean value of RDW was 13.9% (range 13.0% to 15.5%). CONCLUSION: Increased RDW in HCL is associated with active disease and is reversible after successful therapy. This phenomenon has not been reported in the literature yet. Preliminary results show that the increase of RDW may be due to the dyserythropoiesis.
The paper addresses the problem of (1) the relationship of choline in extracellular fluid and acetylcholine (ACh) synthesis in chambers of the heart of white rats, and (2) the possibility of physiological involvement of this ACh in the control of cardiac activity. Within 60 min after s.c. administration of choline in the dose of 300 mg/kg body weight the ACh content rose to 136% of the control value in isolated heart chambers and after administration of 400 mg/kg body weight to 159% of the control value. Increased ACh synthesis failed to affect the heart rate, nor did it increase the tonic effect of vagus innervation of the heart. Excessive ACh could however be released by electric transmural stimulation of isolated heart chambers as well as by potassium depolarization. The release depended on the presence of calcium ions. The obtained results demonstrate that an increase in the level of choline in extracellular fluid results in increased ACh synthesis in nerve terminals. Enhanced release of this ACh is a precondition for high choline levels to induce an increase in parasympathetic control of cardiac function.
Thrombocyte concentrates are vitally important in thrombocytopenic types of haemorrhage. If repeated transfusions are necessary, they are associated with immunological reactions, which cause side-effects in the recipient and the transfusion is ineffective. Donors should be selected according to the HLA system. The authors prepared a programme in the Redap language for selection of donors according to HLA antigens (loci A and B) which respects cross reactions and split antigens. The donor is selected by the grade of agreement with the recipient. The authors differentiate between nine possibilities from complete agreement to complete disagreement between donor and recipient. The initial experience revealed that the programme is feasible for the user and is sufficiently quick.
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Hemodynamic data, including simultaneously measured left ventricular pressure, aortic pressure, and cardiac output, were obtained in 17 patients with isolated valvar aortic stenosis, before and during infusion of dobutamine, isoprenaline, dopamine, and pacing. Infusion of sympathomimetic drugs resulted in a significant increase of both mean and peak systolic aortic valve gradient, cardiac output, heart rate, and systolic aortic valve flow per second. On the other hand, the calculated aortic valve area did not change significantly in spite of variable alterations of all values used for calculating aortic valve area and different causes of hemodynamic changes induced. Aortic valve area is considered a better indicator of the severity of aortic stenosis than is the aortic valve gradient and thus a more suitable indicator for operation.
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