Search PubMed⌕ Search

Biomedical subjects

M Beránek

Publications and source records attributed to M Beránek.

At least 19 recordsLinked to original sources

[Importance of quantitative evaluation of BCR-ABL transcripts using real-time PCR for effective treatment of chronic myeloid leukemia].

BACKGROUND: Molecular biology methods based on reverse transcription and polymerase chain reaction (RT-PCR) are able to detect the presence of BCR-ABL transcripts in chronic myeloid leukemia (CML). In this study we present our experience with monitoring of residual disease using real-time PCR with hybridization probes detection in patients treated with imatinib mesylate and in collected peripheral blood progenitor cells (PBPC). METHODS AND RESULTS: We measured the level of BCR-ABL transcripts in peripheral blood cells of 27 subjects before and in the course of the imatinib treatment. The median of relative quantity of BCR-ABL in the blood before imatinib therapy was 2.55%. The number of the transcripts in 23 imatinib-sensitive subjects decreased to 0.02% in 6 months. After 12 months of the treatment the BCR-ABL median was 0.005%. Subsequent levels fluctuated between values below the detection limit (DL, 0.001%) and 0.005%. Three patients were primarily resistant to imatinib with the BCR-ABL range of 0.13%-11.7% during the treatment. One subject showed marks of molecular relapse after 18 months of the treatment. Only two of 16 filgrastim-stimulated patients had BCR-ABL levels in the blood and in collected PBPC below DL. In other subjects BCR-ABL transcripts were determined within the measurable range of RT-PCR. CONCLUSIONS: Taking into account prognostic importance, the measurement of BCR-ABL transcripts is an effective approach to monitoring of residual CML kinetics. Evaluation of BCR-ABL levels in collected PBPC can complete information on quality of the cells in potential autotransplants, and choose subsequent therapeutic protocols and patient prognosis.

Adult↗

[Frequency view on genome changes testing].

Laboratories dealing with human genome, both inherited and acquired changes, dispose with similar methods and technology. The spectrum of genetic tests is relatively broad and the number of mutations or variants tested differs substantially. Also the number of examinations carried out in individual laboratories varies. Data presented in the tables come from the year 2004 and indicate the number of examinations requested and number of positive results. Many laboratories mentioned in the registry CZDDNAL (http://www.uhkt.cz/lab_a_vysetreni/nr lab_dna_diag/dna_lab_db) perform the same tests but there is also a great number of tests carried out by only one laboratory. Reasons of the request, cost-effectiveness and clinical utility of genetic testing is being discussed.

Gene Frequency↗

["Unknown" cause of the onset and recurrence of venous thromboembolism].

We reported the case of 61 years old man with the first episode of massive pulmonary embolism at the age of 54 without the proper explanation of the cause. Thrombocythaemia was manifested after the dismissal from the hospital but the origin of this condition was not clarified. Essential thrombocythaemia was diagnosed after the recurrence of venous thromboembolism and that is the explanation for thrombophilic condition in this patient. The patient is without problems and signs of recurrent venous thromboembolism after the achievement of the complete remission of myeloproliferative disease and well-managed of anticoagulation therapy.

Humans↗

[Combination of imatinib and anagrelide in treatment of chronic myeloid leukemia in blastic phase].

Chronic myeloid leukemia in blast phase (BP) is resistant to chemotherapy and majority of patients die within 6 months. Inhibitor Bcr-Abl tyrosine kinase imatinib mesylate dramatically improved outcome of patients in chronic phase (CP) and is also effective in BP of CML. The prognosis of patients treated with imatinib in BP is worse than in CP. High platelet counts are often observed at diagnosis or in the subsequent course of the CML in about 25% of patients. Thrombohemorrhagic complications associated with the thrombocythemia may be serious. Anagrelide selectively reduces circulating platelets and is used in treatment of thrombocythemia in chronic myeloproliferative disorders. Efficacy and safety of combination imatinib mesylate with anagrelide was demonstrated in chronic and accelerated phase of CML. No study about the use of imatinib with anagrelide in BP has been found. 51-year-old white man with CML presented in blast phase was followed for 4 years. Imatinib mesylate in dose of 600 mg p.o. qd. was administered after the failure of initial chemotherapy. The patient was treated with imatinib for 45 months, 14.5 months in combination with anagrelide. Partial hematologic response in duration of 33 months was induced by imatinib, cytogenetic response was not reached. Imatinib-resistant thrombocythemia was controlled with anagrelide in dose of 0.5-1 mg p.o. qd. No thrombohemorrhagic complications were observed. The patient tolerated the combination of imatinib and anagrelide well and long-term survival gave him the chance of treatment with the new tyrosin kinase inhibitor (dasatinib).

Antineoplastic Agents↗

[The frequency of venous thromboembolism in women with Leiden mutation in association with pregnancy and puerperium].

OBJECTIVE: The assessment of the frequency of venous thromboembolism (VTE) in women with F V Leiden in association with pregnancy and puerperium and according these results and available data to formulate the principles of thromboprophylaxis. TYPE OF STUDY: Retrospective case control study. MATERIALS AND METHODS: The assessment of frequency of VTE in the group of 224 women with F V Leiden in heterozygous form in association with 460 pregnancies and in the group of 40 women with F V Leiden in homozygous form in association with 70 pregnancies. This frequency of VTE in those groups was compared with the frequency of VTE in the control group of 201 women without F V Leiden in association with 422 pregnancies. F V Leiden evaluation was done in the period of 1996-2003. RESULTS: In the group of women with F V Leiden in heterozygous form VTE occurred 44-fold during pregnancy and puerperium. In 17 cases VTE was manifested in pregnancy (once in Ist trimester, twice in IInd trimester, 14 times in IIIrd trimester), in 27 women VTE occurred in puerperium and always within the first 10 days after delivery. Proximal venous thrombosis was diagnosed in 34 cases, in 5 cases being complicated by pulmonary embolism. In 10 women thrombosis was distal. The frequency of VTE is 9.6%. In the group of women with homozyous form VTE occurred in 14 cases (20%). In 5 cases VTE occurred during pregnancy, in 9 cases after delivery and in all cases within first 2 weeks after delivery. The frequency of VTE in the control group is 0.24%. The results were statistically assessed by Fishers exact test in programme NCSS 2004. Frequency of VTE in both cohorts of women with F V Leiden reached statistical significance in comparison with the control group. CONCLUSION: Pregnancy and puerperium are significant risk factors for VTE in the group of women with F V Leiden in heterozygous form and mainly in homozygous form.

Factor V↗

[The influence of long-term growth hormone replacement therapy on body composition, bone tissue and some metabolic parameters in adults with growth hormone deficiency].

A syndrome of growth hormone deficiency in adults (GHDA) is a syndrome characterised by metabolic deviations, body composition abnormalities, fatigue, decreased quality of life and some cardiovascular changes. The aim of the study was to assess the influence of the growth hormone (GH) replacement therapy on body composition, bone changes, serum lipids levels and some parameters of sugar metabolism in the course of 7-year monitoring. We followed 34 individuals of mean age of 41.73 +/- 2.49 years (mean +/- SE). Severe deficiency of GH was demonstrated by performing stimulation insulin tolerance test. Duration of treatment was 4.13 +/- 0.36 years (mean +/- SE). Patients were examined before the initiation of replacement therapy, after 6 months and further in yearly visits. To determine a statistical level of significance in individual parameters we compared initial baseline status (before drug administration) with the status in individual time intervals. The body composition was examined by anthropometric methods, bioelectric impedance and by densitometry, bone changes were examined by means of DEXA. There were no statistically significant changes of weight, but the waist circumference significantly decreased (p < 0.05), as well as the sum of skinfold thickness (p < 0.05) within the whole treatment period. The percentage of body fat mass measured by the BIA method was significantly changed after the period of 3 years (p < 0.05). Upon the densitometrical measurement of the body composition a significant decrease in kilograms of body fat mass (FM) occurred in the first year of the treatment (p < 0.05) and an increase in lean body mass (LBM) in kilograms during our complete monitoring (p < 0.05). A statistically significant increase in bone density was found in the whole-body BMD and BMC after the first year of the treatment. In the examination of peripheral bone changes a statistically significant increase in BMD occurred (expressed as a Z score) in the area of proximal femur after the first year and collum femoris after three years (p < 0.05), there was a significant increase in BMD of the lumbar spine already after one year of the treatment (p < 0.05) and changes were significant also in further four years. There were found no statistically significant changes related to the sugar metabolism. In the field of lipid metabolism a decrease of total and LDL cholesterol occurred already after a half of the year of the treatment (p < 0.05), changes were significant also in further four years. HDL cholesterol levels have had a progressive tendency, but they were not statistically significant. Positive changes of body composition, an increase in bone density and a decrease of total and LDL cholesterol were demonstrated in the course of the growth hormone replacement therapy.

Adult↗

[Imatinib mesylate (Glivec) in treatment of chronic phase chronic myeloid leukemia].

The new knowledge in molecular biology and pathophysiology of chronic myeloid leukemia enabled the development of imatinib mesylate (Glivec, formerly STI571). Imatinib potently inhibits several protein tyrosine kinases, including BCR-ABL, c-Kit, and PDGF receptor. Imatinib blocks the phosphorylation of downstream target proteins and interrupts the malignant transformation leading to the development of CML. Phase I and II studies demonstrated that imatinib is highly effective and well tolerated in all phase of CML. We got our experience with imatinib on more than two-year monitoring 34 patients within the Expanded Access Study CST1571 0113. Imatinib 400 mg/d was administered orally to 10 women and 24 men in median age of 53 years (22-70) who were hematologically (n = 9) or cytogenetically (n = 13) resistant, cytogenetically refractory (n = 3) or intolerant (n = 9) to interferon alpha. The median follow-up time was 97.5 weeks (23-115), the median time from CML diagnosis to the start of the study was 32.3 months (6-140.5). Complete hematologic response was achieved in 33 of 34 (97%) pts, total major cytogenetic response (complete plus major) in 21 of 33 (63%) pts. Cytogenetic relapse was observed in 2 of 33 pts (6%), cytogenetic progression in 4 (12%) pts. Non-hematologic toxicity was mild (grade 1 or 2) and no patient was excluded from the study due to it. Hematological toxicity grade 3 limited dose of imatinib in 26% of patients and probably caused lower rate of cytogenetic responses in heavy pretreated patients. Both quantitative RT-PCR methods (competitive RT-PCR and real-time RT-PCR Light-Cycler) were found useful to monitor patients with CML on imatinib therapy. Our results confirmed high efficacy and safety of imatinib in late-chronic phase CML patients failing prior interferon therapy. The lower incidence of hematological toxicity and higher rate of cytogenetic responses in patients treated with imatinib in early-chronic phase CML justify according to our opinion the recommendation to administer imatinib early after the diagnosis of CML in patients who are not indicated for allogeneic transplantation.

Adult↗

[Incidence of selected antiphospholipid antibodies in a group of patients with systemic lupus erythematosus].

Antiphospholipid antibodies (APLA) present very heterogeneous groups of antibodies which can significantly and in various ways influence processes on different levels of coagulation cascade. Their presence can be accompanied with repetitive venous and arterial thromboses, recurrent loses of foetus, and thrombocytopenia. Incidence of these thrombotic disorders was monitored in a group of 46 patients with systemic lupus erythematodes (SLE). Positive lupus anticoagulant (LA), antiphospholipid antibodies complex, and thrombocyte counts were assessed. Thrombotic disorders were assessed in a retrospective analysis. In the LA+ group 62% of patients had history of venous thromboses, 31% had history of arterial thromboses, and 18% had history of spontaneous abortions. In a group without positive LA 18% of venous thromboses (p = 0.0006) and 6% of arterial thromboses (p = 0.03) were indicated. In the assessment of spontaneous abortions no statistically significant difference was found. An average value of thrombocytes in LA+ group was 152 +/- 66 x 10(5)/l, in LA- group 223 +/- 86 x 10(5)/l, which is statistically significant difference (p < 0.05). In the assessment of thrombotic disorders in a group with combination LA+ and APA+ statistical significance was indicated only in venous thromboses (p = 0.004). We can state from the results that in thrombotic disorders which can be seen in the framework of systemic tissue disorders positive LA and APA and a range of other factors such as activity of a basic disease, associated diseases, and treatment which can aggravate thrombotic disorders of individual patients can participate.

Abortion, Spontaneous↗

Inhibitory effect of glycation on catalytic activity of alanine aminotransferase.

Non-enzymatic glycation is a common post-translational modification of tissue and plasma proteins which can impair their functions in living organisms. In this study, the authors have demonstrated for the first time an inhibitory effect of in vitro glycation on the catalytic activity of alanine aminotransferase (ALT, EC 2.6.1.2), a pyridoxal phosphate enzyme with several lysine residues in the molecule. The porcine heart enzyme was incubated with 50 mmol/l D-fructose, D-glucose, D,L-glyceraldehyde, or D-ribose in 0.1 mol/l phosphate buffer (pH 7.4) at 25 degrees C for up to 20 days. The strongest glycation effect was shown by D,L-glyceraldehyde, which caused complete enzyme inhibition within 6 days. After 20 days of incubation, the ALT activity in samples with D-fructose and D-ribose was less than 7% of the initial enzyme activity. A statistically significant effect of D-glucose on the enzymatic activity of ALT was not found. Incubation of ALT with D-fructose, D,L-glyceraldehyde and D-ribose minimized its catalytic activity both in the glycated and non-glycated fractions of the samples. Markedly higher activity was found in the glycated fraction with glucose. The inhibitory effect of glycation of ALT with D-fructose and D-ribose was found to be more intensive in the presence of L-alanine and weaker in the presence of 2-oxoglutarate. The findings suggest that glycation of the epsilon-amino group of Lys313 as a crucial part of the catalytic site of ALT may contribute to ALT inactivation in the presence of glycating sugars. Nevertheless, glycation of lysine residues outside the active center of ALT seems to be primary.

Alanine↗

Identification of novel common polymorphisms in the promoter region of the TIMP-3 gene in Czech population.

We investigated possible polymorphisms in the promoter regions of the TIMP-1, 2 and 3 genes (tissue inhibitor of metalloproteinases) to establish their frequencies in the Caucasian population. Polymorphisms were analysed by means of heteroduplex analysis and fragments with altered mobility were sequenced. No polymorphisms were found in the promoters for TIMP-1 and 2 but three novel polymorphisms (-899T/A, -915A/G and -1296T/C) were identified in the promoter region of the TIMP-3. Allele frequencies in a sample of healthy Caucasian subjects (n=95) were determined by PCR followed by restriction analyses with specific endonucleases. Allele frequencies of the -899A, -915G and -1296C polymorphisms were 0.05, 0.39 and 0. 40, respectively. We conclude that the -915A/G and -1296T/C variants of the TIMP-3 gene appear to be common polymorphisms in the Caucasian Czech population.

Aged↗

In-vivo indices of CYP2D6 activity: comparison of dextromethorphan metabolic ratios in 4-h urine and 3-h plasma.

OBJECTIVES: Dextromethorpan (DM) is widely used as a probe drug to assess in vivo the activity of the cytochrome P450 2D6 (CYP2D6). The aim of the study was to compare metabolic ratios (MRs) of DM to dextrorphan (DEX) in plasma and urine. We examined, separately in urine and plasma, the relationships between the MRs which are based on DEX and those involving the sum of DEX and a secondary metabolite hydroxymorphinan (HM). Furthermore, we compared the MRs in plasma obtained with and without hydrolysis of DEX glucuronides. METHODS: Concentrations of DM and metabolites in urine and plasma were determined by HPLC after a single oral dose of 30 mg DM hydrobromide to 101 healthy Caucasian subjects. Urine was collected over the time interval 0-4 h after the dose and plasma was obtained from 95 subjects 3 h after administration. RESULTS: Six subjects (5.9%) were of poor metaboliser (PM) phenotype (urinary DM:DEX ratio >0.3). A good correlation (r2 = 0.777, P < 0.00001) was observed between the metabolic ratios of DM:DEX in plasma and urine. There was an excellent correlation, both in plasma and urine, between the log-transformed ratios of DM:DEX and of DM to the sum of molar concentrations of DEX and HM (r2 > 0.996, P < 0.00001). Plasma samples of 89 subjects (83 EM and 6 PM) were analyzed without deconjugation of DEX glucuronide also. The correlation between the plasma ratios of DM:DEX based on unconjugated DEX and those involving glucuronide (r2 = 0.793, P < 0.00001) was comparable to that reported by other authors on urine. CONCLUSION: In healthy Caucasian subjects, the MRs of DM to DEX in plasma obtained at 3 h correlated reasonably well with those in urine collected over the time interval 0-4 h after the dose. Nevertheless, repeatability of this plasma index should be determined before its wide use can be recommended. Finally, the interindividual variation in DEX metabolism to HM (catalyzed by CYP3A) contributes only minimally to the interindividual variability of the MRs.

Adult↗

[Heterogeneity of the frequency of the apolipoprotein E-epsilon 4 allele in the European population].

BACKGROUND: Apolipoprotein E (apo E) is one of the most important constituents of plasma lipoproteins. A genetic polymorphism in the 4th exon of the apo E gene determines the existence of epsilon 2, epsilon 3 and epsilon 4 alleles in human population coding for three common isoforms of apo E: apo E2, apo E3, and apo E4. The aim of the study is to present the heterogeneity of the epsilon 4 allele frequency in the European region. METHODS AND RESULTS: The mean frequency of the epsilon 4 allele is 13.6% in the whole European population (95%) confidence interval: 7.2-20.0%; 45 evaluated studies, 19940 subjects). Frequency of the epsilon 4 is 17.7% in Northern Europe (12.0-23.4%; 11 studies, 4564 subjects), 15.5% in Western Europe (10.9-20.0%; 21 studies, 11,615 subjects), 12.8% in Central Europe (9.1-16.5%; 5 studies, 939 subjects), and 8.0% in Southern Europe (3.2-12.8%; 8 studies, 2822 subjects). The mean frequency of epsilon 4 allele established preliminary in two localities (Prague, Hradec Králové) in the Czech Republic is 15.7% (15.5-15.9; 2 studies, 95 subjects). CONCLUSIONS: The study confirmed an apo E-epsilon 4 frequency heterogeneity in the European population. The occurrence of epsilon 4 allele decreases from the North to the South in Europe. The highest frequency of epsilon 4 allele is in Finland (mean 22.1%), the lowest in Sardinia (5.2%).

Alleles↗

Survey of serum potassium reference measurements.

We compared the quality of reference measurements for serum potassium in four reference laboratories from three different European countries, using a panel of 60 native patients' samples. The reference methods were based on either ion chromatography (one laboratory) or flame atomic emission spectrometry (three laboratories). Performance specifications for serum potassium measurements were defined as a maximum overall coefficient of variation (CV) of 1.5%, a maximum bias of 0.65% and a maximum total error of 3.0%. The overall imprecision for all laboratories was in the range of 0.7 to 1.3%, and was thus below the proposed specification of 1.5%. However, two laboratories reported 12 and 13 quadruplicates with CVs exceeding this limit. The mean bias (expressed as deviation from the overall mean of all laboratories) for all reference laboratories was < 0.65%. In the lower concentration range, however, one laboratory exceeded this limit. No laboratory measured samples with a total error above 3.0%. From these results, it can be concluded that the reference measurements, and, thus, also the reference methodologies, based on ion chromatography and flame atomic emission spectrometry were equivalent, and able to satisfy current analytical specifications for serum potassium measurements.

Chromatography, Liquid↗

A relationship between K-ras gene mutations and some clinical and histologic variables in patients with primary colorectal carcinoma.

Mutations in the Kirsten ras 2 (K-ras) gene were described as early events in the process of colorectal carcinogenesis. The aim of this study was to find a possible relationship between the presence of K-ras mutation in samples of primary colorectal carcinomas and the clinico-pathological data of the investigated patients. Mutation in codon 12 of the K-ras gene was determined in 18 of 53 colorectal carcinomas (34%) in our group of patients. The presence of K-ras gene mutations was not related to gender, age of subject at diagnosis, staging or cancer location (p > 0.05). Sixteen of the 42 (38%) moderately differentiated carcinomas, and two of the eight (25%) well differentiated carcinomas contained K-ras mutation in codon 12, but none of the three poorly differentiated carcinomas contained the mutation. Moderately differentiated tumours contained an aspartate code GAT (in eight cases), a valine code GTT (in six cases), an alanine code GCT (in one case) and a serine code AGT (in one case) in codon 12. Well differentiated tumours contained only the valine code GTT (two cases). Our results show that the frequency of mutations in the K-ras gene in carcinomas in Central Europe is not different from the frequencies found in other parts of the world. The homogeneous incidence of K-ras mutation does not seem to be related to ethnic factors, dietary habits, or the composition of the diet.

Adult↗

[Pharmacologic importance of glycation of plasma proteins].

A short review provides basic information about the influence of glycation of plasma proteins, as a complication of uncompensated diabetes mellitus, on binding parameters of drugs from various pharmacological groups. There are many facts about the influence of diabetes on binding sites of plasma proteins, but only a relation between the free fraction of sulphonamides and the degree of albumin glycation was described. Observed changes of free fractions of other drugs in diabetic patients are related rather to a competition of these drugs with free fatty acids or other endogenic metabolites for albumin binding sites than to glycation reaction itself. A current clinical status and results of biochemical and pharmacokinetic analyses are necessary for an objective survey of efficiency of pharmacological treatment in diabetic patients.

Blood Proteins↗