Novel sialidase from non-pathogenic bacterium Oerskovia paurometabola strain O129.

Bacterial sialidases are enzymes that are involved in a number of vital processes in microorganisms and in their interaction with the host or the environment. Their wide application for scientific and applied purposes requires the search for highly effective and non-pathogenic producers. Here, we report the first description of sialidase from Oerskovia paurometabola. The extracellular enzyme preparation was partially purified. The presence of sialidase was confirmed in native PAGE treated with the fluorogenic substrate 4MU-Neu5Ac. Maximum enzyme activity was registered at 37 °C and in the pH range of 4.0-5.5. The influence of metal ions and EDTA was examined. It was demonstrated that EDTA, Mn2+ and Ba2+ ions inhibit the sialidase activity to different extent, while Cd2+, Fe2+ and Fe3+ have stimulating effect on it. These features are studied for the first time concerning sialidase of Oerskovia representative. Cell bound sialidase and sialate aldolase were also established.

Increasing procoagulant activity of circulating microparticles in patients living with HIV.

OBJECTIVES: HIV-infected individuals are at higher risk of non-AIDS diseases associated with procoagulant status. Microparticles are elevated in disorders associated with thrombosis (e.g., cardiovascular diseases). We investigated the association between microparticle levels in untreated and treated HIV-infected subjects, and determined the association with immune status, viral replication, and duration of antiretroviral therapy. PATIENTS AND METHODS: We included 144 HIV-infected subjects, including 123 on antiretroviral therapy (ART) and 21 before treatment initiation. A control group of 40 HIV-negative healthy adults matched for age and sex was used for comparison of microparticle levels. Treated subjects were divided into five groups depending on the period of antiretroviral exposure. Statistically significant differences were determined by Kruskal-Wallis test and Chi2 test. The relation between microparticles and other parameters was assessed using Spearman's coefficient of correlation. RESULTS: Microparticle levels were significantly higher in treated and untreated HIV-infected subjects than in non-HIV-infected controls (P<0.001). The microparticle level was similar between the groups on treatment (P=0.913). No association between the microparticle level and CD4+ count, CD4+/CD8+ ratio, number of HIV-1 RNA copies, or duration of exposure to antiretroviral treatment was observed. CONCLUSION: Increased levels of microparticles may be due to processes independent of viral replication and CD4+ cell count, and microparticle release might persist even during viral suppression by antiretroviral treatment. Elevated microparticle levels might occur in response to other triggers.

High Level of Circulating Microparticles in Patients with BCR/ABL Negative Myeloproliferative Neoplasm - a Pilot Study.

BACKGROUND: Microparticles (MPs) are small (0.1-1 μm) cell-derived vesicles released during activation or apoptosis, with a surface-exposed phosphatidylserine along with antigens indicating the cellular origin. The level of MPs is known to be elevated in thromboembolic diseases and malignancies; it is believed that MPs are not only amplifying but can also initiate the thrombogenesis processes. BCR/ABL negative myeloproliferative neoplasms (MPNs) are clonal haematopoietic diseases, which include polycythemia vera, essential thrombocythemia and primary myelofibrosis. One of the main problems of MPN patients is high risk and incidence of thrombosis which affect the survival, quality of life and life expectancy. PATIENTS AND METHODS: The clinical significance of circulating MPs was assessed in a group of 179 patients with BCR/ABL-negative MPNs. Analysis of MPs was done using flow cytometry on 417 samples, and MPs procoagulation activity was performed using a functional assay called Zymuphen MP-activity (Hyphen Biomed, Neuville-sur-oise, France) on 274 samples. RESULTS: Significantly higher absolute and relative count of platelet MPs was found in MPN patients when compared with healthy group, respectively (p = 0.001, p = 0.043). Erythrocyte MPs were also significantly higher in MPN patients than in the healthy group (p < 0.001). Procoagulation activity of MPs was as well significantly higher in patients compared to the control group (p < 0.001). Patients with primary myelofibrosis had decreased absolute and relative count of platelet MPs compared to polycythemia vera and essential thrombocythemia patients, respectively (p = 0.008, p = 0.014). Presence of JAK2V617F mutation was associated with higher absolute and relative count of platelet MPs, respectively (p = 0.045, p = 0.029). CONCLUSION: Although some literature data support the hypothesis of a direct relation between MPs and thrombotic events in MPN patients, further studies are needed to evaluate the clinical implication of MPs in the hypercoagulation state of MPN patients.

Spontaneous retroperitoneal hematoma - our experience with surgical approach.

Spontaneous retroperitoneal hematoma is a serious complication of anticoagulation and antiplatelet therapy. Its incidence has increased in recent years due to an increasing number of patients on this treatment. A number of case series have been described in the literature. In the vast majority of cases, the hemodynamically stable patients were treated either conservatively or by selective radiological embolization of the bleeding source. A surgical approach is reported as a last choice in the cases where the conservative therapy fails, radiological intervention is unavailable, in patients with continuous bleeding or in patients who develop abdominal compartment syndrome. In our case report, we present a patient on anticoagulation therapy for deep venous thrombosis complicated by massive retroperitoneal bleeding: surgery was used as the method of first choice and the treatment was successful. Key words: retroperitoneal hematoma bleeding anticoagulation treatment surgery.

Patterns in anticoagulant utilization in the Czech Republic during 2007-2017.

Direct oral anticoagulants (DOACs) have gradually entered the Czech market as alternatives to vitamin K antagonists and parenteral anticoagulants since 2008. Considering the eventual changes, the aim was to evaluate drug use and expenditure patterns on anticoagulants in the Czech Republic. A retrospective utilization study was conducted retrieving data from the State Institute for Drug Control database, including reports on drug supplies from distributors with anatomical therapeutic chemical classification (ATC) codes B01AA, B01AB, B01AE, B01AF, and B01AX. The utilization on national level was expressed as the ratio of the number of defined daily doses per 1000 inhabitants per day (DDD/TID). Expenditures on all anticoagulants were also assessed. Data was analyzed using PASW (version 18.0). Between January 2007 and December 2017, the national anticoagulant utilization rate increased continuously from 14.15 to 27.67 DDD/TID. The use of DOACs was 0.002 DDD/TID in 2008, increased to 6.04 DDD/TID in 2017. Warfarin utilization, after a small decrease in 2008, has shown nearly stable levels in the recent years (70.9% of all anticoagulants; mean 11.55 DDD/TID over the last 5 years), while its increase was halted by the spread of DOACs utilization (p < 0.05). In 2017, over half of the expenditures (51.1%) were due to oral anticoagulants, whereof 47.6% was related to DOACs. The results reflected a growing utilization and increasing costs of all anticoagulants, especially in DOACs at the expense of warfarin. Still, additional information regarding patient persistence and prescribing patterns is needed for a better understanding of oral anticoagulant utilization.

Low-burden TP53 mutations in chronic phase of myeloproliferative neoplasms: association with age, hydroxyurea administration, disease type and JAK2 mutational status.

The multistep process of TP53 mutation expansion during myeloproliferative neoplasm (MPN) transformation into acute myeloid leukemia (AML) has been documented retrospectively. It is currently unknown how common TP53 mutations with low variant allele frequency (VAF) are, whether they are linked to hydroxyurea (HU) cytoreduction, and what disease progression risk they carry. Using ultra-deep next-generation sequencing, we examined 254 MPN patients treated with HU, interferon alpha-2a or anagrelide and 85 untreated patients. We found TP53 mutations in 50 cases (0.2-16.3% VAF), regardless of disease subtype, driver gene status and cytoreduction. Both therapy and TP53 mutations were strongly associated with older age. Over-time analysis showed that the mutations may be undetectable at diagnosis and slowly increase during disease course. Although three patients with TP53 mutations progressed to TP53-mutated or TP53-wild-type AML, we did not observe a significant age-independent impact on overall survival during the follow-up. Further, we showed that complete p53 inactivation alone led to neither blast transformation nor HU resistance. Altogether, we revealed patient's age as the strongest factor affecting low-burden TP53 mutation incidence in MPN and found no significant age-independent association between TP53 mutations and hydroxyurea. Mutations may persist at low levels for years without an immediate risk of progression.

Minimal Residual Disease Assessment in Multiple Myeloma by Multiparametric Flow Cytometry.

BACKGROUND: Progress in treatment of multiple myeloma extensively increased patient remission rates, so minimal residual disease (MRD) detection becomes essential to assess the effectivity of treatment and depth of complete response. Nowadays, multiparametric flow cytometry (MFC) is the most used method for monitoring of MRD presence in the bone marrow of multiple myeloma patients; however, detection on molecular level can be used as well. It is evident that choice of protocol used for MFC-MRD assessment can significantly affect required results; nevertheless, standardized and highly sensitive approach of "next generation flow" is already available. Although benefit of MRD assessment as an independent predictor of progression-free survival and overall survival is known, very recent research showed that MRD-negative status surpasses the prognostic value of complete response achievement for progression-free survival and overall survival. AIM: This review is focused on use MFC in MRD assessment in multiple myeloma. The technical aspects and clinical benefits of this approach are mentioned as well. CONCLUSION: The information about MRD level detected by highly sensitive and reproducible MFC can be potentially used as a biomarker to evaluate the efficacy of different treatment strategies, help on treatment decisions and act as a surrogate for overall survival in multiple myeloma patients.Key words: multiple myeloma - minimal residual disease - flow cytometry - plasma cells.

Biobanking - the First Step to Successful Liquid Biopsy Experiments.

BACKGROUND: Archiving of biological materials in biobanks is considered to be the initial crucial part of research activities. Most often, biobanks are founded for research purposes since they allow collection of sufficient material for analysis of new or testing of previously identified biomarkers. Biobanking needs to quickly react to current needs of researchers as well as clinicians, it is not a rigid system. Laboratory analyses of monoclonal gammopathies are based on separation of plasma cells from bone marrow of patients. A specific problem is usually a lack of tumor cell fraction, which is due to location of tumor cell in bone marrow in combination with low infiltration. One of the challenges in clinical research is the necessity of changes in biobanking for samples allowing detection of minimal residual disease in the bone marrow but also from peripheral blood by the so-called liquid biopsies. AIM: The aim of this review is to show the importance of archiving biological material in the Czech Republic and to show concrete examples of its usage in hematooncology. CONCLUSION: A general problem in solving many research questions is the availability of a critical amount of specimens for statistical analysis. Obtaining critical amount of specimens of biological material can be quickly archived by cooperation of biobanks sharing both methodological standards and informations about the availability of samples for research projects.Key words: archiving - biological material - informed consent - multiple myeloma - plasma cells.

Circulating Plasma Cells in Monoclonal Gammopathies.

BACKGROUND: Monoclonal gammopathies are characterized by presence of clonal plasma cells in the bone marrow, although peripheral blood circulating plasma cells can be found in a significant proportion of patients. The number of circulating plasma cells is an independent prognostic marker associated with shorter survival, but it can also help to predict early relapse. The reason and mechanism of plasma cell expansion from the bone marrow to enter peripheral blood is still not entirely clear, but possible changes in the expression of adhesion molecules are probably involved. Multiparametric flow cytometry allows simple and exact enumeration of circulating plasma cells in different types of cell suspensions, even in their low quantity. The phenotype profile and confirmation of clonality regarding to their bone marrow clonal counterparts should be verified as well. There is no uniform method used in clinical laboratories for circulating plasma cells analyses at this moment. AIM: Review is focused on use of multiparametric flow cytometry for circulating plasma cells analysis in peripheral blood. It is comparing possibilities of their detection by different methods and on clinical relevance of that assessment. The standardization of analyses is the main goal. CONCLUSION: Multiparametric flow cytometry is a very sensitive method for detection of circulating plasma cells, so using a standardized approach can lead to determination and implementation of the flow cytometry diagnostic threshold in plasma cell leukemia suspicious cases as well as in prognostication of monoclonal gammopathies patients. Moreover, analysis of plasma cells phenotypic profile could probably clarify their future behaviour.Key words: monoclonal gammopathies - circulating plasma cells - plasma cell leukemia - flow cytometry.

Biomarkers in Immunoglobulin Light Chain Amyloidosis.

Immunoglobulin light chain amyloidosis (AL amyloidosis - ALA) is a monoclonal gammopathy characterized by presence of aberrant plasma cells producing amyloidogenic immunoglobulin light chains. This leads to formation of amyloid fibrils in various organs and tissues, mainly in heart and kidney, and causes their dysfunction. As amyloid depositing in target organs is irreversible, there is a big effort to identify biomarker that could help to distinguish ALA from other monoclonal gammopathies in the early stages of disease, when amyloid deposits are not fatal yet. High throughput technologies bring new opportunities to modern cancer research as they enable to study disease within its complexity. Sophisticated methods such as next generation sequencing, gene expression profiling and circulating microRNA profiling are new approaches to study aberrant plasma cells from patients with light chain amyloidosis and related diseases. While generally known mutation in multiple myeloma patients (KRAS, NRAS, MYC, TP53) were not found in ALA, number of mutated genes is comparable. Transcriptome of ALA patients proves to be more similar to monoclonal gammopathy of undetermined significance patients, moreover level of circulating microRNA, that are known to correlate with heart damage, is increased in ALA patients, where heart damage in ALA typical symptom.Key words: amyloidosis - plasma cell - genome - transcriptome - microRNA.

[Current Recommendations for the Prevention and Treatment of Venous Thromboembolism in Cancer Patients]. / Aktuální doporucení pro prevenci a terapii venózní trombembolické nemoci u onkologicky nemocných.

About 20% of patients suffer from venous thromboembolism (VTE) during oncology disease. Active cancer, along with cancer therapy, increases the risk of VTE, especially in the first 6 months after diagnosis. Most often VTE accompanies haematological malignancies and CNS tumours, and gastrointestinal, breast, lung, ovary and uterine cancer. The presence of distant metastases, together with the implantation of a central venous catheter, increases the risk even more. A cancer patient also has a 2-5× higher risk of recurrence of VTE during anticoagulant therapy than patients without a malignancy, as well as a 2-6× higher risk of serious bleeding. Thromboembolic disease is also an independent prognostic factor for death in patients with malignant tumours. Management of VTE is a part of everyday oncological practice, and oncologists should be aware of the basic recommendations regarding individual medical procedures and the clinical situations that may occur in cancer patients. They should also be able to adequately treat VTE when it occurs. It is necessary to consider some specificity during prophylaxis, diagnostics and treatment of venous thromboembolism in cancer care. The International Initiative on Thrombosis and Cancer (ITAC-CME) has created a mobile application based on international guidelines for the prevention and treatment of venous thromboembolism. It is a simple schematic algorithm for making decisions, and it helps in choosing the best therapeutic strategy and supports the judicious and appropriate use of anticoagulants for prophylaxis and treatment of VTE in cancer patients. This text contains a summary of the recommendations applicable in routine clinical practice.Key words: venous thromboembolism - cancer - central venous catheter thrombosis - guidelines This work was supported by Czech Ministry of Health - RVO (MMCI, 00209805). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 1. 8. 2016Accepted: 26. 10. 2016.

[The effectiveness of anagrelide treatment in patients with Ph negative myeloproliferative diseases: influence on the incidence of thrombosis in the data from the Registry of patients with essential thrombocythemia and thrombocythemia associated with other myeloproliferative diseases treated with Thromboreductin® to the end of 2012]. / Úcinnost lécby anagrelidem u nemocných s Ph negativními myeloproliferativními chorobami: ovlivnení výskytu trombózy ve výstupech Registru pacientu s dia-gnózou esenciální trombocytemie a trombocytemie provázející jiné myeloproliferativní onemocnení lécených Thromboreductinem® ke konci roku 2012.

In the Czech Republic, anagrelide (Thromboreductin®) [29] is used according to the recommendations of the Czech Working Group on Myeloproliferative Disorders (CZEMP) for treatment of thrombocythemia associated with Ph negative myeloproliferative disorders (MPDs). The patient data are collected in the Registry of patients with essential thrombocythemia (ET) and thrombocythemia associated with other MPDs treated with Thromboreductin®. At the end of 2012, the Registry contained data on 1,161 patients. Out of these, 1,159 patients with the dia-gnosis of a Ph negative MPD were evaluated. In 844 patients, precise WHO based dia-gnosis was known at start of therapy: 442 (52.4%) had ET, 108 (12.8%) had polycythaemia vera (PV) and 243 had primary myelofibrosis (PMF). The median age was 51 years at the time of diagnosis. At the time of the evaluation of the population, the median was 59 years. Every year, the proportion of patients newly treated with anagrelide as a firstline treatment in accordance with the CZEMP guidelines has been increasing. A growing proportion of patients has been treated with an additional cytoreducing drug, such as hydroxyurea and interferon. The majority of the patients received also an antiaggregant (or anticoagulant). More than a half of patients harbors the JAK2 mutation. A prompt decrease of platelet counts (as the response to Thromboreductin® treatment) was documented in most of the patients. After one year, 86.9% of patients had a full or partial response. In poorer responders, combination cytoreductive treatment was administered rather then the escalation of the Thromboreductin® dosage. There were 461 thrombotic manifestations in 363 patients and 61 haemorrhagic events in 57 patients recorded in the patients history. In the course of treatment (followup; F U), thrombosis was diagnosed only 179-times in 136 patients. There were more haemorrhagic events during F U: 109 events in 83 patients. Upon comparison of the number of events during F U to their numbers in history, we found a twofold decrease in arterial thrombosis, an almost twofold decrease in microvascular thrombosis and even a 6.6- fold decrease in venous thromboembolism events. Bleeding episodes increased 1.8-fold during F U. However, the vast majority of these hemorrhagic events were clinically insignificant. In conclusion, the treatment strategy according to the CZEMP guidelines incorporating anagrelide is highly effective in reducing the platelet counts, strongly prevents venous events, reduces arterial events, and leads to an increase of minor hemorrhages.

Clinical impact of PAI 1 4G/5G gene polymorphism in colorectal carcinoma patients.

Plasminogen activator ihnibitor (PAI 1) belongs to the plasminogen activator system, which is part of the metastatic cascade and significantly contributes to invasive growth and angiogenesis of malignant tumors. Its plasma level is normally low but 4G/4G homozygotes have higher concentrations of PAI 1. This genotype may be associated with worse prognosis and proximal location of colorectal cancer than 5G/5G homozygotes. In our prospective evaluation we examined plasma level PAI 1 (using photometric microplate method ELISA) pre-surgery and, subsequently, 6-8 weeks later, from 80 patients. For the PAI 1 rs1799889 -675 4G/5G polymorphism test the PCR amplification was used.Analysis of collected data was confirmed that significantly higher plasma levels of PAI 1 were found in patients before starting therapy, which decreased (p=0.004) after initiation of treatment. Patients with higher plasma level PAI 1 before (p=0.013) and after therapy (p=0.004) had significantly shorter survival. We found no relationship between polymorphisms of PAI 1 (-675 4G/5G) in relation to stage, survival or tumor location. PAI 1 is useful as a negative marker of prognosis and could be advantageous when planning adjuvant treatment of patients with colorectal carcinoma. Although opinions on the importance of polymorphisms of PAI 1 in relation to the prognosis are not uniform, it does seem that their role in the prognosis of patients with colorectal cancer is not essential.

[Peripartal life-threatening hemorrhage - interdisciplinary consensus opinion]. / Peripartální zivot ohrozující krvácení - mezioborové konsenzuální stanovisko.

22 experts from the fields of gynecology and obstetrics, anesthesiology and resuscitation, intensive care, hematology and transfusion medicine has developed recommendations for diagnosis and procedure for life-threatening peripartum haemorrhage, which is still one of the most common causes of maternal mortality in childbirth. This guidelines, which is valid for the Czech Republic, supported by a total of 10 professional medical societies. There are based on new knowledge applicable at this time and is focused mainly on eliminating the most common causes of bleeding during delivery and prevention of haemorrhagic shock.

[Disturbances of hemostasis in sepsis]. / Poruchy hemostázy u sepse.

Immune system and hemostasis are closely bound together. When one of these systems is activated, another is set in motion too. This is especially noticeable in polytraumas, inflammation, shocks etc. The most important activator of immune system and hemostasis is sepsis. In sepsis there is a vigorous stimulation of immune response because of a liberation of a lot of cytokines and proinflammatory molecules. This may lead to an extrem picture of systemic inflammatory response syndrome. In systemic inflammatory response syndrome a downregulation of thrombomodulin and endothelial protein C receptor on the surface of intact endothel may be detected and there is an upregulation of release of the tissue-type plasminogen activator with a switch to plasminogen activator inhibitor 1 release. There is lowering of activated protein C and fibrinolytic activation followed by fibrinolytic inhibition in septic patients. Consequently we can see consumption of coagulation factors, inhibitors (antithrombin, protein C, and tissue factor pathway inhibitor), microangiopatic hemolysis and thrombocytopenia with a picture of disseminated intravascular coagulation in these patients. The diagnosis of disseminated intravascular coagulation is not uniforme in the literature. Expression of tissue factor on monocytes and endothelium may aggravate this "circulus vitiosus" with serious microcirculatory failure in sense of MOF/MODS (mutliorgan failure/multiorgan dysfunction syndrome). The first steps in the therapy of sepsis represent the treatment of cause of sepsis, vigorous hydratation and maintenance of circulation and pulmonary function, glycemic control etc, the prevention and blocking of the undesirable activation of hemostasis and inflammation being equally important. The treatment with minidoses of heparin was implemented in the past and the question, if this therapy is indicated is not answered yet. The clinical studies of the suitability of the treatment with natural inhibitors of hemostasis (antithrombin, recombinant human activated PC or drotrecogin α activated, rhTFPI) were evaluated in the past and are still under way recently. The unequivocal contribution of these therapies was not proven and recombinant human activated PC was even pulled from the worldvide market.

[Prognostic significance of morphology in multiple myeloma]. / Prognostický význam morfologického hodnocení u mnohocetného myelomu.

BACKGROUNDS: Multiple myeloma is the second most common hematological disease caused by clonal proliferation of B cells. Evaluation of number of plasmocytes in the bone marrow is still one of the basic diagnostic criteria. The aim of this study was to verify if this evaluation has prognostic value even in the era of new drugs. MATERIAL AND METHODS: Two groups of MM patients were enrolled in this study. The group T - 45 newly diagnosed MM patients who underwent treatment with thalidomide. Group B - 86 patients in first relapse of MM without autologous transplantation of bone marrow that were treated with thalidomide and bortezomib in various combinations. Percentage of subtypes of plasmocytes in the bone marrow was evaluated based on progressive analysis of nucleus, chromatin and nucleo-cellular ratio (N/C). RESULTS: Mature plasma cells were found in 53.3% (group T) and 53.5% (group B) of patients; proplasmocytes I were found in 22.2% (group T) and 24.4% (group B) of patients; proplasmocytes II were found in 22.2% (group T) and 22.1% (group B) of patients and plasmablasts in 1% (group T) and 0% (group B). Patients who reached treatment response after first treatment had statistically significant number of proplasmocytes II when compared to group without treatment response (median 37% vs. 11%, p = 0.033). Group B patients with mature plasmocytes below 10% had significantly shorter overall survival than other patients when comparison of quartiles was performed. Group B patients with higher infiltration of proplasmocytes I than median of 15% had lower overall survival (median 50.3 months vs. 74.9 months, p = 0,024); the same was true for evaluation of proplasmocytes II (median OS 41.3 months vs. 74.9 months, p = 0,011). CONCLUSION: Numerical evaluations of plasma cells in the bone marrow remain basic diagnostic criteria of MM even in the era of new genomics analyses. More precise morphological evaluation of 8 subtypes of plasma cells brings important prognostic information that is necessary for new protocols for immunomodulatory drugs and proteasome inhibitors.

[Significance of urokinase and its inhibitors in the invasiveness and metastasing of malignant tumors]. / Význam urokinázy a jejích inhibitoru pro invazi a metastazování zhoubných nádoru

Fibrinolysis is process, which leads to the degradation of fibrin to fibrin monomers. Fibrinolysis helps to regulate hemostasis and prevents the creation of inappropriately large thrombus, which could reduce blood flow to the bloodstream. The main enzyme involved in fibrinolysis is plasmin. Tissue plasminogen activator (tPA) and urokinase (uPA) are agents converting plasminogen into active plasmin, together with urokinase receptor (uPAR) and urokinase inhibitors (PAI 1, PAI 2, PAI 3 and protease nexin) form plasminogen activator system (PAS) which is among others also part of the metastatic cascade and significantly contributes to invasive growth and angiogenesis of malignant tumours. In contrast to tPA that is fundamental in fibrinolysis, uPA plays an essential role in tissue degradation as part of physiological and pathological processes. uPAR is a GPI (glycosylphosphatidylinositol)-anchored protein. The binding of uPA to uPAR results in activation of protein tyrosine kinase, protein kinase C and MAP kinase. At the same time, direct signalling pathway via Jak/STAT cascade utilising signalling transduction of Scr-like protein tyrosine kinase have also been described. uPAR expression is regulated by many growth factors, e.g. EGF, FGF-2 and HGF. It seems that individual PAS factors are involved in the process of rendering malignant tumors invasive. To what degree this influence is essential to specific malignancies, should be answered by further research. In the article the authors present a summary of findings about the interaction of fibrinolysis and tumor process, especially on the effects of urokinase and other activators and their inhibitors in metastasis of malignant tumors. The text contains information on the factors theirs introduction into practice is still the subject of numerous discussions, but in the future, individual PAS factors could play an important role in planning treatment strategies and also could become targets of targeted therapy.

Flow cytometry in monoclonal gammopathies.

The technological development of flow cytometry (FC) together with new findings reveal the need for immunophenotyping in research of monoclonal gammopathy (MG) because of its diagnostic, prognostic and predictive significance. The aim of the European Myeloma Network (EMN) is to standardize this analytical method and implement it into routine clinical examination. Since the overall significance and application of FC are still analysed, standardisation could help obtain more clinical relevant information in terms of MG pathophysiology.