Biomedical subjects

J Kovarík

Publications and source records attributed to J Kovarík.

At least 19 recordsLinked to original sources

PubMed2005

Lack of STAT 1 phosphorylation at TYR 701 by IFNgamma correlates with disease outcome in melanoma patients.

STAT 1, a member of signal transducer and transcription activator family has been implicated as key downstream mediator of interferon (IFN) signaling. Its functional activation requires phosphorylation at Tyr 701 and Ser 727 residues. Various STAT abnormalities have been found in cancer cells but their relation to oncogenesis, tumor behavior and disease outcome remains mostly unknown. We have examined the inducibility of STAT 1 phosphorylation by IFN alpha/gamma in primary cultures established from melanoma lymph node metastases at first progression and correlated our results with disease outcome and overall survival. Forty-four patients at clinical stage I-III at initial diagnosis entered the study. STAT 1 inducibility of phosphorylation by IFNs was assessed in melanoma cell lysates by means of standard immunoprecipitation and Western blotting using polyclonal and monoclonal antibodies. Lack of STAT 1 phosphorylation at Ser 727 after either IFN was recorded in 75% of patients, however, no correlations with disease evolution could be proved. In contrast, STAT 1 phosphorylation response at Tyr 701 after IFNalpha occurred in 13 (29.5%) and after IFNgamma in 32 (73%) patients. Inducibility of STAT 1 activation at Tyr 701 but not at Ser 727 driven by IFNgamma but not by IFNalpha significantly and unfavorably [corrected] influenced disease- free interval and overall survival. In conclusion, these results show that the absence of IFNgamma inducibility of STAT 1 phosphorylation at Tyr 701 positively correlates with disease outcome in malignant melanoma patients and may represent new independent prognostic marker.

Adult↗

PubMed2003

Interferon inducibility of STAT 1 activation and its prognostic significance in melanoma patients.

STAT 1, a member of latent cytoplasmic proteins, plays a pivotal role in mediating biological effects of interferons. Its transducing, DNA binding and transcriptional activity require phosphorylation at both Tyr 701 (Y 701) and Ser 727 (S 727) residues. Deficient phosphorylation or constitutive activation of the STAT 1 protein were observed in some human malignancies. Using immunoprecipitation and Western blots performed with lysates made of melanoma cells derived from patients with clinical stage II/III and employing specific anti-STAT 1 PS 727/PY 701 immunoprobes, we show that STAT 1 activation response induced by IFN-alpha/-gamma is significantly impaired. On average, three quarters of patients were lacking phosphorylation at S 727. STAT 1 PY 701 was not inducible by IFN-alpha in 63% and by IFN-gamma in 34% of samples. However, these STAT 1 activation defects showed no correlation with the disease outcome and immunotherapy response as indicated by progression-free survival profiles in patients treated with IFN-alpha2b.

DNA-Binding Proteins↗

PubMed2003

Inhibition of adhesion breast cancer cells by anticoagulant drugs and cimetidine.

Recent studies suggest that anticoagulant drugs and cimetidine therapy in malignancy may improve cancer survival and inhibit the metastatic process. In this study we investigated and compared the effects of anticoagulant drugs (unfractionated heparin, warfarin, acetylsalicylic acid, low-molecular-weight heparins--nandroparinum, enoxaparinum, dalteparinum and reviparinum), cimetidine and combination of cimetidine with anticoagulants on adhesion of highly invasive breast cancer cells lines - BT 549 and MDA-MB-231 (MDA 231)--in vitro. High antiadhesion effect was observed with cimetidine, warfarin and acetylsalicylic acid. Low-molecular-weight heparins had a small antiadhesion effect in independent use. In combination with cimetidine, a potential effect of cimetidine on the antiadhesion was observed. The antiadhesion effect was dependent on the type of the cancer cell line. Different effects between cell lines BT 549 and MDA 231 were observed. The strongest antiadhesion effect was obtained using the combination of cimetidine with acetylsalicylic acid. In the majority of applications of the drugs and their combinations, a proportional antiadhesion effect was dependent on the concentration and time. We suppose that anticoagulant drugs might have higher antimetastatic effect in combination with cimetidine. The choice of anticoagulants can decrease the adhesion, decrease tumor angiogenesis and cause the shortening of blood clotting time. Cimetidine can decrease the adhesion of cancer cells and increase the activity of NK cells. Indeed, according to our results, application of cimetidine and anticoagulant drugs intensifies the antiadhesion effect together with other antimetastatic effects.

Aged↗

PubMed2002

Malignant melanoma associates with Th1/Th2 imbalance that coincides with disease progression and immunotherapy response.

The immunological dysfunction associated with human cancer is well known phenomenon. It comprises number of pathological changes within immune network including imbalance in cytokines of Th1/Th2 origin. The objectives of our study were (i) to evaluate the abnormalities in serum levels of selected cytokines in malignant melanoma patients with regional lymph node metastases as compared to normal values, (ii) to examine the relationship between postoperative cytokine levels and disease progression and (iii) to correlate cytokine profile changes during IFN-alpha therapy with the disease progression and potential therapeutical response. Nine Th1/Th2 related cytokines and sIL-2R were determined in 26 malignant melanoma patients at clinical stage III prior and during adjuvant immunotherapy. Control group consisted of 26 healthy persons. Patients were treated with rIFN-alpha according to EORTC Melanoma group protocol 18952. Cytokines were quantified in patients sera using commercial ELISA kits. Majority of melanoma patients showed significantly lower values of IL-2 and IFN-gamma and pathologically elevated levels of IL-4, IL-6, IL-10 as compared to healthy subjects what indicates disease associated Th1/Th2 imbalance. In addition increased IL-12 and IL-15 values were noted in some patients (54% and 27%, respectively). All patients who manifested early relapse during immunotherapy had significantly lower pretreatment levels of IL-2 and IL-12 than those remaining without progression and probably benefiting from the treatment. Cytokine changes during immunotherapy disclosed that decreases in IL-2 and IL-12 and raises in IL-6 and IL-10 values occurred at least one month prior to relapse. Moreover, the continuous elevation of TNF-alpha and sIL-2R could be observed in patients who remained without progression during 10 months lasting immunotherapy. Our data illustrate that malignant melanoma associates with Th1/Th2 perturbances which are directed towards extended Th2 responses and that measurement of selected cytokines of Th1/Th2 category may be used as an early signal of disease deterioration and for evaluation of immunotherapy response.

Adult↗

PubMed2001

[Radical radiotherapy of prostate carcinoma].

Radiotherapy is an effective treatment modality of prostate carcinoma. Considering the limited radiosensitivity of this tumour it is necessary to use relatively high doses of radiation. Modern technology offers the possibility to perform high-dose radiotherapy with acceptable toxicity. The authors present various options of both external and internal irradiation. They point out that brachytherapy, previously considered less appropriate from the radiobiology aspect, is according to the current views and results a very suitable treatment modality of prostate cancer.

Brachytherapy↗

PubMed2001

Metastatic MHC class I-negative mouse cells derived by transformation with human papillomavirus type 16.

In the endeavour to develop a model for studying gene therapy of cancers associated with human papillomaviruses (HPVs), mouse cells were transformed with the HPV type 16 (HPV16) and activated H-ras oncogenes. This was done by cotransfection of plasmid p16HHMo, carrying the HPV16 E6/E7 oncogenes, and plasmid pEJ6.6, carrying the gene coding for human H-ras oncoprotein activated by the G12V mutation, into secondary C57BL/6 mouse kidney cells. An oncogenic cell line, designated MK16/1/IIIABC, was derived. The epithelial origin of the cells was confirmed by their expression of cytokeratins. No MHC class I and class II molecules were detected on the surface of MK16/1/IIIABC cells. Spontaneous metastases were observed in lymphatic nodes and lungs after prolonged growth of MK16/1/IIIABC-induced subcutaneous tumours. Lethally irradiated MK16/1/IIIABC cells induced protection against challenge with 10(5) homologous cells, but not against a higher cell dose (5 x 10(5)). Plasmids p16HHMo and pEJ6.6 were also used for preventive immunization of mice. In comparison with a control group injected with pBR322, they exhibited moderate protection, in terms of prolonged survival, against MK16/1/IIIABC challenge (P < 0.03). These data suggest that MK16/1/IIIABC cells may serve as a model for studying immune reactions against HPV16-associated human tumours.

Animals↗

PubMed2001

[Risk assessment of irradiation of tissue with metal implants].

Authors examine the influence of metal implants on the distribution of ionizing radiation in tissue. In vivo measurements in a patient are seldom possible. The risk can be assessed with sufficient accuracy on the basis of various experimental dosimetric methods, histological changes in the irradiated volume and the tolerance to the physical stress, published in the available literature. The analysis shows that the risk of significant dose inhomogeneity or the treatment toxicity is minimal if mentioned principles are adhered to. Radiotherapy indications and dosage should not be markedly changed on the basis of the presence of metal in the irradiated volume.

Humans↗

PubMed2000

Longitudinal follow-up of antibody response to selected antigens of human papillomaviruses and herpesviruses in patients with invasive cervical carcinoma.

A group of 21 cervical-carcinoma patients was followed longitudinally. All patients had undergone intensive radiotherapy. In the course of a more than 5-year observation period, 2 patients died of cervical cancer, 1 from other causes, 3 were lost from follow-up, and 15 survived without any signs of the disease. Sera taken before, up to 17 months after and more than 5 years after the start of therapy, were tested by ELISA for IgG antibodies reactive with a broad spectrum of HPV-derived antigens, glycoprotein G of HSV 2, whole virion antigen of HCMV, and a synthetic peptide corresponding to the immuno-dominant region of EBNA 1. The therapy was associated with a marked decrease in E2 and E7 antibodies in nearly all patients possessing pre-existing antibodies; the changes in VLP antibody levels in the treated women were more rare and less pronounced. In the course of the observation period, seroconversion to gG HSV2 positivity was seen in 5 patients, while, a marked increase in pre-existing gG HSV2 antibodies was observed in 5 out of 7 originally seropositive patients. At enrollment, only 2 patients were free of HCMV antibody and only 1 was free of EBNA1 antibody; no seroconversion relative to either antigen was seen during the observation period.

Adult↗

PubMed2000

[Papillomaviruses and human tumors].

The report summarizes the main results obtained in the course of our research project. The results of immunological and epidemiological studies provide further proofs that human papillomaviruses (HPV) are the etiological agents in cervical neoplasia. In addition, they raise hopes that immunological methods may be utilized in diagnostics of cervical cancer and for monitoring the clinical course of this disease in the near future. Since the etiological relationship between HPV and cervical carcinoma seems to be proven beyond reasonable doubt, the development of prophylactic and therapeutic vaccines has become the dominant of the contemporary HPV reseach. For studying immune reactions against HPV-induced tumours we developed a model of HPV16-transformed rodent cells.

Female↗

PubMed1999

Renal cell carcinoma-associated immune impairment that may interfere with the response to cytokine therapy.

This prospective study was carried out to explore cytokine-related immune alterations in 69 renal cell carcinoma patients (RCC) and to look for changes which might potentially serve as a reliable predictors of response to cytokine-based therapy. Interleukin-2 (IL-2), its soluble receptor (sIL-2R) and tumor necrosis factor (TNF-alpha) levels produced in vitro by PHA activated and intact mononuclear cells (PBMC) were determined. Concentrations of IL-2, IL-4, IL-6, sIL-2R, TNF-alpha and CRP were measured in sera. Cytokine level was evaluated by enzyme-linked immunoadsorbent assay (ELISA) and CRP was determined by means of turbidimetric method. All measurements were performed in patients without any prior treatment. PHA activated PBMC of RCC patients were significantly defective in producing IL-2 and TNF-alpha comparing to controls (p < 0.03 and p < 0.001). The difference of sIL-2R was noted in metastatic stage only (p < 0.03). Unstimulated PBMC manifested decrease in IL-2 (p < 0.03) and increased level of TNF-alpha in advanced disease (p < 0.02). This impairment reflected tumor size and differentiation stage. Serum concentrations of IL-2, sIL-2R and TNF-alpha were within normal range. However, in relation to the clinical stage, significantly increased serum IL-2 was noted in combined Stage I and II as compared to controls (p = 0.012). IL-6 and CRP showed markedly elevated levels with a significancy which allowed to distinguish samples from metastatic patients. In conclusion careful comparisons of these data with clinical course of cytokine treated patients will disclose which of those tests may possess predictive power in the individual patients who are likely to respond to cytokine-based treatment.

Adult↗

PubMed1999

p53 status in breast carcinomas revealed by FASAY correlates well with p53 protein accumulation determined by immunohistochemistry.

The prognostic and predictive value of p53 mutation in breast cancer is still conflicting. The choice of the p53 status detection method may account for some discrepancies. In this pilot study we compared two differently-based methods for detection of p53 alteration in 32 breast carcinoma samples: the immunohistochemical method using Bp53, DO1 and DO11 monoclonal antibodies for analysis of the p53 protein accumulation in cell nuclei and the functional method FASAY. FASAY - functional analysis of the separated alleles in yeast - tests the capability of the human p53 to transactivate a reporter with a p53 binding site RGC driving the ADE2 gene in yeast. In our group the percentage of breast cancers with accumulated p53 protein was 50%, as well as percentage of mutant p53 scored by FASAY was 50%. Although the agreement of both methods, when comparing the results of individual patients was high (94%), our results show that immunohistochemistry does not reflect the p53 status quite exactly.

Adult↗

PubMed1998

Prognostic value of bone marrow biopsy in operable breast cancer patients at the time of initial diagnosis: Results of a 20-year median follow-up.

From May 1975 until May 1980,128 operable breast cancer patients, clinical stage I-II, had a core bone marrow biopsy (BMB) from the posterior iliac crest as a part of the routine diagnostic work-up at the time of initial diagnosis. The mean age of the patients was 56 years, range 26-93. In a previous study on this material, 10 patients (7.8 per cent) were positive for tumor cells and 118 negative by conventional histopathology of BMB [1]. In 1996 we reexamined all BMB separately at two laboratories, using monoclonal antibodies against cytokeratins AE1-AE3, KL1, CAM 5-2 (DOP), and DC10, BA17 (MCI). The number of extrinsic cells in the bone marrow was graded positive for micrometastases when > or = 5 cells or suspicious when 1-4 cells per approximately 2 x 10(6) bone marrow cells were found, using high power field magnification. Micrometastases were detected in 17 patients (13.3 per cent) and another 8 patients were classified as suspicious. The presence of micrometastases was correlated to the axillary lymph node stage and primary tumor location. Median follow-up was 20 years. All 17 micrometastatic patients relapsed and died within 6 years of disease progression with evident osseous metastases. There was one disease-free survivor of the 8 patients with suspicious BMB after 17 years of follow-up. The median overall survival was significantly shorter in tumor-cell positive patients, being 1.9 years compared to 11.7 years in the BMB negative and BMB suspicious groups (p < 0.0001). Immunohistochemical analysis of core BMB taken postoperatively may be useful in predicting the prognosis in patients with breast cancer clinical stage I-II.

Adult↗

PubMed1998

[Prenatal diagnosis and therapy of congenital diaphragmatic hernia].

The diagnosis and treatment of congenital diaphragmatic hernia, CDH, is an interdisciplinary problem. The patient concentration with prenatally diagnosed CDH for comprehensive examination with subsequent decision on the type of delivery improves the prognosis of patients with CDH. Introduction of corticoid therapy in prenatally assessed CDH reduces dysfunction and surfactant deficiency and can reduce the degree of respiratory failure during delivery. In very early prenatally assessed CDH it is possible to consider the possibility of combined corticoid and TRH (thyroxin releasing hormone) treatment of CDH. The authors submit also contemporary possibilities of prenatal intervention treatment of CDH (indication criteria for reconstruction operations of foetal surgery, intrauterine closure of the trachea and artificial laparoschisis). The concentration of patients with postnatally diagnosed CDH and a severe grade of acute respiratory insufficiency in a department with conventional and non-conventional artificial pulmonary ventilation incl. inhalation of NO oe extracorporeal membrane oxygenation, ECMO, is a further step towards optimation of treatment. Continuous evaluation of parameters of pulmonary functions during the pre- and postoperative period may prove that a therapeutic protocol with delayed surgery is useful.

Female↗

PubMed1997

Epitope analysis of the human p53 tumour suppressor protein.

Using a set of overlapping peptides of the human p53 protein, we have performed an accurate mapping of the p53 antigenic sites, recognized by a panel of 19 monoclonal antibodies from the Bp53 series. The results show that most of the antibodies recognize determinants localized in the amino-terminal domain of the protein. Several antibodies reacted with peptides which correspond to the antigenic determinants localized in the carboxy terminus of p53. None of these antibodies reacted with peptides in the central DNA-binding domain of p53 protein.

Amino Acid Sequence↗

PubMed1996

[Practical results of monitoring pregnancy in women with systemic lupus erythematosus].

BACKGROUND: The authors dealt with the urgent problem under what conditions it is possible to achieve in a woman with systemic lupus erythematosus (SLE) or another collagenosis, or secondary antiphospholipid syndrome (APS) a favourable outcome of pregnancy and the delivery of a healthy infant. METHODS AND RESULTS: The investigation comprised 23 women incl. 20 with SLE, two with the mixed form of a diffuse connective tissue disease (MCTD) and one with Sjögren's syndrome of the primary type. From the total number of 20 pregnancies six were consulted in advance with a doctor (group I-s-called planned pregnancies) and all terminated by a successful delivery. Of 11 pregnancies which were not consulted with a doctor in advance (group II-so-called unplanned pregnancies) 9 were terminated in term, however, only 5 with a successful delivery (55.5%), two women are still pregnant. Exacerbation of the basic disease during pregnancy was recorded only once and did not lead to discontinuation of the pregnancy. CONCLUSIONS: The authors provide evidence that desired pregnancy of informed women suffering from SLE or another collagenosis when assisted by a specialized medical team can lead to a successful delivery of an infant.

Adult↗

PubMed1996

A constitutional de novo mutation in exon 8 of the p53 gene in a patient with multiple primary malignancies.

We report a constitutional point mutation of codon 278 in exon 8 of the TP53 gene that has not yet been described as a germ-line mutation. A 52-year-old female developed multiple primary malignancies (liposarcoma, breast cancer, malignant histiocytoma, occult adenocarcinoma). The mutation found in her tumour and peripheral blood lymphocyte DNA is a cytosine to thymine transition at the second position of codon 278 resulting in an amino acid exchange from proline to leucine in the DNA-binding domain. Evaluation of the patient's family revealed that both of her sons were affected by the same mutation. Although the patient's mother had died already, we were able to demonstrate by polymorphic microsatellite analysis that the defective allele originated from the maternal side. As four brothers and one sister had inherited the same allele, which however was wild type, we were able to show that the mutation must have occurred in the germ cells of the patient's mother and that it may therefore be called de novo. This explains the lack of a high cancer incidence in the family history. All tumours tested showed positive immunohistochemical staining for p53. Loss of heterozygosity was found in five of seven tumours, one showing chromosome 17 monosomy.

Alleles↗

PubMed1996

[The quality of documentation in patients after conservative surgical procedures in breast carcinoma and its effect on subsequent therapy].

The quality of data was evaluated in 50 patients referred for adjuvant treatment to the Department of Radiotherapy and Oncology, University Hospital "Královské Vinohrady" after conservative surgery for breast cancer. The authors suggest improving the cooperation between surgeon and radiation oncologist. The purpose of this study is to establish the criteria for conservative surgery of breast carcinoma and to evaluate, if the data provided by surgery and pathology departments are sufficient for radiation oncologist to complete high quality postoperative radiotherapy.

Adult↗

PubMed1996

Changes of Ki67 index of various tumors during radiation therapy.

This study investigates the changes in the Ki67 labeling index during radiotherapy (RT) of seven patients with primary breast carcinoma, one patient with metastatic bronchial squamous cell carcinoma and one patient with a paraumbilical deposit of a large bowel adenocarcinoma. The material was taken by fine needle aspiration either from the primary tumors or the metastases. In four patients with primary breast carcinoma, we observed a drop in the Ki67 labeling index after 24 h (2 Gy), but an increase after 18 days (26 Gy). In one patient the pattern was different. An increase after the initial fraction was followed by a decrease after 18 days of radiotherapy. In two patients with primary breast carcinoma, where the second sample was aspirated after 72 h (3 fractions of RT, 6 Gy), the values of Ki67 labeling indexes before RT were higher than after RT. In two patients where the material was aspirated from metastatic deposits, we observed an increase of Ki67 labeling index after 24 h (2 Gy). Possible explanations, including repopulation following the suppression of the synthesis in the originally active clonogens after radiation injury, are discussed.

Adenocarcinoma↗