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Biomedical subjects

Z Kolár

Publications and source records attributed to Z Kolár.

At least 19 recordsLinked to original sources
PubMed2006

[Bone marrow angiogenesis in patients with multiple myeloma as a marker of biological behaviour].

Angiogenesis, the creation of new blood vessels from preexisting vascular nets, plays a major role in the development, progression and dissemination of solid malignant tumors. Research over the last few years has shown a correlation of angiogenesis and the biological behaviour of haematologic malignancies. This study focused on the relation of vasoformation, stage of differentiation of tumour plasmocytes and type of bone marrow infiltration in patients with multiple myeloma (MM) prior to treatment. We evaluated trephine biopsy samples from 55 patients for microvessel density in 1 mm2 field by monoclonal antibody anti CD34. Angiogenesis correlated with the type of infiltration and with stage of morphological differentiation. It was highest in the nodular type of infiltration with a low level of differentiation, and lowest in grade 1 differentiation with an interstitial type of infiltration.

Aged↗
PubMed2006

[Proliferative and apoptotic markers in prostate carcinoma in relation to androgen receptor].

Prostate carcinoma, one of the most frequent male malignancies, is in certain stages of its development significantly influenced by androgens. Therefore, we carried out a retrospective study on a set of 130 patients with nongeneralized, localized prostate carcinoma (stage T1-T2, PSA up to 25 ng/ml). We determined immunohistochemically the expression of proliferation markers PCNA and Ki67, Bax, p53, Bcl-2, p21waf1, p27kiP1 and compared them with the expression of the androgen receptor (AR). Multivariation statistical analysis of the results using the chi-square test with Pearson's correction and variability analysis using the SPSS 8.0 software program showed a strong correlation of the PCNA and Ki67 proliferation markers with the expression of hormonal dependence and apoptosis markers. The expression of PCNA correlated strongly with p27 kip1 and Bax, while the expression of Ki67 correlated most strongly with p27 kip1 and Bcl-2. The expression of p27 kip1 correlated with the expression of androgen receptor, PCNA, Ki67 as well as Bcl-2. None of the observed markers correlated significantly with Gleason's score. We did not find substantial significant relation between the observed markers and the expression of p53 and p21 waf1. The results indicate a significant role of the expression of p27 kip1 protein in regulating proliferative activity and hormonal responsiveness in the initial stage of prostate carcinoma.

Apoptosis↗
PubMed2006

Analysis of ERBB2 and TOP2A gene status using fluorescence in situ hybridization versus immunohistochemistry in localized breast cancer.

The aim of our study was to assess the ERBB2 and TOP2A gene status in breast carcinoma tissue using fluorescence in situ hybridization (FISH) and to compare their amplification with immunohistochemistry assay (IHC) of the ERBB2, resp. topoisomerase IIalpha proteins. TOP2A status is important in tailored treatment as topoisomerase IIalpha is the molecular target for topoisomerase IIalpha inhibitors. This study was conducted to determine whether the methods are equivalent in their assessment of TOP2A status and to correlate the genetic findings with basic tumor and disease characteristics. Locus specific ERBB2, TOP2A genes and chromosome 17 centromeres (CEP17) probes were hybridized to 72 formalin-fixed paraffin-embedded (FFPE) tissue samples from patients with non-metastatic breast carcinoma (M0). The ERBB2, TOP2A and CEP17 signals were counted and gene numbers per nucleus or per CEP17 were calculated, respectively. Sections were also stained with commercial polyclonal antibody (HercepTestTM), anti-topoisomerase IIalpha monoclonal antibody (clone SWT3D1) and scored for the presence of membrane/nuclear staining. ERBB2 amplification was found in 20.3%, ERBB2 and TOP2A co-amplification was detected in 14.5% of cases. Deletion of the ERBB2/TOP2A gene was found in 1.4/2.8% of sections, respectively. Concordance of FISH and IHC techniques in the evaluation of ERBB2 and TOP2A status was found in 88.4% and 66.7%, respectively. The low concordance of FISH versus IHC in the evaluation of TOP2A status was mainly due to the presence of TOP2A amplified tumors in IHC negative or weakly positive specimens. Topoisomerase IIalpha expression was increased in bigger tumors, although direct correlation with tumor grading was not found. ERBB2 amplification was found in more aggressive breast cancers with grades 2 and 3, respectively. Interestingly, chromosome 17 polysomy was more frequently observed among older women (>55 years), suffering usually from less aggressive disease. Our results confirm the high concordance of the ERBB2 and TOP2A gene co-amplification in breast carcinoma. Differences between FISH and IHC in the case of ERBB2 gene status were found only in IHC 2+ sections as reported in the literature. However, our study points to the importance of FISH examination of TOP2A gene status in all tumors with ERBB2 amplification.

Adult↗
PubMed2005

Comparison of protective effect of protein and DNA vaccines hsp90 in murine model of systemic candidiasis.

Preventive vaccination by a hsp90-expressing DNA vaccine and recombinant hsp90 protein vaccine, both derived from the Candida albicans hsp90 using BALB-c mouse model of systemic candidiasis, was performed. Hsp90 mRNA was cloned from a clinical isolate of C. albicans, converted to cDNA and cloned into vaccination plasmid pVAX1. Two methods of DNA application were tested: intramuscular (i.m.) and intradermal (i.d.) injection. Recombinant protein was applied by i.d. injection with Freund's adjuvant; the control groups received PBS or Freund's adjuvant only. Mice were vaccinated and after 19 d re-vaccinated. After 3 weeks, the mice were challenged with the live C. albicans in a dose of 5 x 10(6) CFU per mouse. After the challenge, the mice vaccinated i.d. with DNA vaccine survived for 39 and 64% longer compared to those receiving Freund's adjuvant and/or PBS, respectively. The i.m. application of the DNA vaccine did not provide any significant protectivity. The serum level of anti-candida-hsp90 serum IgG antibodies correlated with the survival rate in both i.d. protein and DNA vaccination approaches. We stressed the importance of specific humoral immunity in the mouse model of systemic candidiasis.

Animals↗
PubMed2005

Nestin as a diagnostic and prognostic marker: immunohistochemical analysis of its expression in different tumours.

The designation NESTIN refers to a member of the family of intermediate filaments and comes from the fact that this protein is expressed mainly in neuroepithelial stem cells. However, nestin is not expressed in mature elements and terminal cell differentiation is associated with loss of immunoreactivity to this protein. Therefore, immunohistochemical assessment of nestin expression might be useful to differentiate between mature and immature elements. The aim of this study was to analyse nestin expression in various tumours of neuroectodermal and vascular origin and to determine whether its detection has practical relevance. The results indicate that the immunohistochemical detection of nestin expression could be useful in astrocytomas and malignant melanomas, where it could be used as an auxiliary indicator of dedifferentiation and progression. Because of the weak and heterogeneous expression of nestin in neurinomas, phaeochromocytomas, and carcinoids, nestin detection in these lesions is of little practical use.

Adolescent↗
PubMed2005

[Immunohistochemical study of the apoptotic and proliferative mechanisms in the intestinal mucosa during coeliac disease].

Mechanisms leading to morphological changes of the small intestine during coeliac disease are not yet completely recognized, however, two main processes have been suggested recently: remodelling of mucosa by matrix metalloproteinases, and mucosal atrophy by apoptosis. The aim of this study was to analyze the expression of proteins regulating apoptosis and some markers of proliferation in the mucosa of the small intestine of children with active (ACD) and latent form (LCD) of coeliac disease (CD). Intestinal biopsies of 43 children with ACD and LCD were analyzed by standard indirect immunohistochemical technique for Fas, Fas ligand (Fas-L), tissue transglutaminase (tTG), Bcl-2, Bid, glutathione S-transferase (GST), CAS 3, CAS 8, PARP, Ki-67, Topoisomerase IIa, PCNA expression. We found significantly lower numbers of Fas-expressing enterocytes in ACD patients than in LCD patients and controls. The number of Fas-positive mucosal lymphocytes was decreased in ACD when compared with LCD. Fas-L expression in enterocytes and mucosal lymphocytes was higher in ACD and LCD compared to controls. We found significantly more Bcl-2 negative lymphocytes in ACD than in LCD and controls. Bid expression in enterocytes was higher in LCD compared to ACD and controls. In intraepithelial lymphocytes, there was higher Bid expression in LCD than in ACD and controls compared to expression in mucosal lymphocytes, where was found higher number of positive cells in controls than in ACD and LCD. Expression of CAS 8 in mucosal lymphocytes was significantly higher in ACD compared to LCD. The expression of tTG in extracellular matrix and basal lamina was significantly higher in LCD and ACD when compared to controls. Expression of tTG was higher in the group of ACD and LCD in the enterocytes and in the lymphocytes. Our findings showed that Fas/Fas-L, Bcl-2, and CAS 8 may be involved in modulation of apoptosis during CD. Increased apoptotic elimination of IEL in LCD can partially explain preservation of the normal villous architecture. Increased tTG expression may be an early sign of increased apoptosis or may be related to its role in CD pathogenesis.

Apoptosis↗
PubMed2004

Nestin expression by newly formed human blood vessels.

Nestin is a type VI intermediate filament protein originally described in neural stem cells. Here we report that immature endothelial cells generated in the course of angiogenesis express nestin. Endothelial cells of embryonic capillaries destined to vascularize growing organs also express this intermediate filament protein. Whereas nestin was sporadically expressed in mature adult human endothelial cells sporadically express nestin, this protein was consistently expressed in adult angiogenic vasculature. Nestin expression was also detected in capillaries of the corpus luteum, which replenishes itself by angiogenesis. Nestin-immunoreactive vessels were also observed in the infarcted hearts where transient ischemia triggered regeneration accompanied with neovascularization of the myocardium. Nestinpositive endothelial cells lined vessels nourishing solid growing tumors, including melanoblastomas and glioblastomas. Our data provide definitive evidence that endothelial precursors express the neural stem cell marker nestin and that this protein participates in formation of the cytoskeleton of newly formed endothelial cells. Because nestin expression was recognized under all conditions of vascular development, nestin represents a novel and reliable marker of neovascularization.

Blood Vessels↗
PubMed2004

Proto-oncogene c-myc in uterine cervix carcinogenesis.

The biological behaviour of precancerous and early stages of uterine cervix carcinoma is not always easily predictable. It is important therefore to identify new biological markers which could more reliably predict the evolution of the disease or provide important therapeutic targets. To establish the role of the proto-oncogene c-myc in uterine cervix tumorigenesis, we examined 96 tissue samples of different degrees of cervical intraepithelial neoplasia (CIN1-CIN 3), in situ (CIS) or invasive squamous cell carcinoma (ISCC) and control cases. Indirect immunohistochemical techniques were used to detect the c-myc expression. Significantly higher levels of Myc protein were found in keratinocytes of high-grade dysplasias in comparison to low-grade dysplasias and control cases. There was no difference between low-grade CIN and a control group of patients. The same significant changes between above mentioned groups were seen in surrounding stromal cells (fibrocytes, fibroblasts, some endothelial cells and lymphocytes). We confirm that expression of c-Myc protein is increased not only in uterine cervix cancer but also in the premalignant lesions. Problem for discussion seems there for whether increased Myc expression in stromal cells might create a more tumor promoting microenvironment which may support the growth and proliferation of transformed cells.

Carcinoma in Situ↗
PubMed2004

Solitary intracranial metastasis of follicular carcinoma of the thyroid gland clinically mimicking a meningioma.

We describe a rare case of solitary metastasis of follicular carcinoma of the thyroid gland into the petroclival region in a 58-year-old woman. The metastasis was the first and only manifestation of the disease. The histology of the tumor, differential diagnosis and clinical course are discussed. In a few similar cases described so far the tumor was always a well or moderately differentiated follicular carcinoma located in the petroclival region. As in this presentation, these cases also clinically mimic a meningioma. The differential diagnosis includes adenoma of the thyroid gland and thyroid gland dystopia. We demonstrated the primary focus of carcinoma within the thyroid after its detailed examination initiated by our finding. The clinical outcome of such rare cases is usually excellent, much better than in metastases of papillary carcinoma into the brain.

Adenocarcinoma, Follicular↗
PubMed2004

Immunohistochemical detection of the hMLH1 and hMSH2 proteins in hereditary non-polyposis colon cancer and sporadic colon cancer.

Defects in DNA mismatch repair system are involved in carcinogenesis of sporadic and inherited human cancers. We assessed the feasibility of using immunohistochemistry to detect tumors with DNA mismatch repair deficiency. We analyzed 81 samples (74 colon cancers (CC), 1 colon dysplasia and 6 extracolonic cancers) for hMLH1 and hMSH2 protein expression, microsatellite instability (MSI) and/or mutational analysis. A meta-analysis of the published data on immunohistochemistry of hMLH1/hMSH2 proteins was performed. Sensitivity and specificity of the method was calculated. Twenty four of 29 tumors from hMLH1/hMSH2 mutation carriers and 10 of 13 sporadic high frequency MSI tumors lost one of the proteins. None of the 42 tumors with stable microsatellites or low frequency MSI lost the proteins. Based on literature review of 49 publications on colorectal cancer, hMLH1 immunohistochemistry was able to detect 136 of 154 tumors from hMLH1 germline mutation carriers (the sensitivity of 88.3% [95%CI, 85.8-90.8%]), hMSH2 immunohistochemistry detected 99 of 109 tumors from hMSH2 mutation carriers (the sensitivity of 90.8% [95%CI, 88.5-93.1%]), and hMLH1/hMSH2 immunohistochemistry identified 1262 of 1382 tumors with high-frequency microsatellite instability not correlated with mutational analysis (the sensitivity of 91.3% [95%CI, 90.4-92.2%]). The specificity of the method was 99.4% (95%CI, 99.2-99.6%). In conclusion, immunohistochemistry of hMLH1 and hMSH2 proteins is a useful method to predict the presence of mismatch repair deficiency, although its sensitivity is lower than that of MSI analysis.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Synergic effects of the cyclin-dependent kinase (CDK) inhibitor olomoucine and androgen-antagonist bicalutamide on prostatic cancer cell lines.

Currently, mechanisms leading to both apoptosis induction and the development of hormone-independence of prostate carcinoma cells are intensively studied. Attention is also given to the possibility of restoring cell sensitivity to hormone-antagonists. The present study focuses on the effect of the combined synthetic cyclin-dependent kinase [CDK] inhibitor, olomoucine and the antiandrogen bicalutamide on hormone-insensitive (DU-145) and hormone-sensitive (LNCaP) prostate cancer cell lines. In both cell lines reduction in cell viability was significantly higher when olomoucine and bicalutamide were applied in combination when compared to separate application of both these drugs. The setting of optimal concentrations for both substances was important for the final effect on both cell lines. The proliferation arrest was accompanied by a decrease in cyclin D1 expression and the activation of p21Waf1/Cip1 and p27Kip1 pathways in both cell lines. Contrary to the previously described effect of 200 microM olomoucine, weak AR induction after treatment with effective concentrations of olomoucine was not seen in the hormone- insensitive cell line DU-145. The related reaction of DU-145 and LNCaP cell lines to treatment with combined olomoucine and bicalutamide likely provides evidence that the inhibitory effect of bicalutamide may not only be associated with its antiandrogenic properties. The tested substances probably influence different regulatory pathways and these have co-operative impact on the cell cycle outcome. Understanding antitumor and antihormone actions of both agents is essential for the development of novel therapeutic schemes integrating substances with different action. Our results show that the combination of synthetic CDK inhibitors and hormone- antagonists may be one of a number of possible alternatives.

Androgen Antagonists↗
PubMed2003

[Diagnosis of lymphoproliferative diseases from bone marrow biopsies].

The cytological, histological and immunophenotypical markers of lymphoproliferative diseases are evaluated in the collection of 950 trepanobiopsies, and correlated with types of extramedullary malignant lymphoma. The diagnostic significance of tumor infiltrates topography and basic rules of the differential diagnoses of malignant lymphomas in the bone marrow biopsies are discussed.

Biopsy, Needle↗
PubMed2002

Synthetic inhibitors of CDKs induce different responses in androgen sensitive and androgen insensitive prostatic cancer cell lines.

AIMS: Because of the high prevalence of prostatic cancer and the limitations of its treatment, enormous effort has been put into the development of new therapeutic modalities. One potential tool is the use of cyclin dependent kinase (CDK) inhibitors, which are based on the trisubstituted derivatives of purine. The aim of this study was to analyse alterations of the regulatory pathways in both androgen sensitive and androgen insensitive prostatic cancer cell lines (LNCaP and DU-145, respectively) after blockage of the cell cycle by the synthetic CDK inhibitors, olomoucine and bohemine. METHODS: The effects of olomoucine and bohemine were studied on the following parameters: (1) cell proliferation, by measurement of DNA content; (2) viability, by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) and/or XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) test; and (3) the expression of p53, pRB, Bcl-2, Bax, p16, p21, p27, cyclins A, B, D1, E, p34(cdc2), and the androgen receptor (AR), by western blot analysis. RESULTS: Both olomoucine and bohemine were potent inhibitors of growth and viability; however, bohemine was two to three times more effective than olomoucine. The sensitivity of LNCaP cells to both agents was significantly higher. After treatment, both cell lines revealed quite different spectra of protein expression. CONCLUSIONS: These results indicate the existence of specific cell cycle regulating pathways in both cell lines, which may be associated with both p53 and AR status. CDK inhibitors exhibited valuable secondary effects on the expression of numerous regulators and thus may modulate the responsiveness of tumour cells to treatment, including treatment with hormone antagonists.

Cell Division↗
PubMed2002

Expression of c-erbB-2 in node negative breast cancer does not correlate with estrogen receptor status, predictors of hormone responsiveness, or PCNA expression.

The aim of this study was to analyse the relationships between the expression of c-erbB-2, estrogen receptor (ER), progesterone receptor (PR), Bcl-2 and PCNA in node negative breast cancer. Expression of these markers was determined by HercepTest, by immunohistochemistry and quantified by morphometry in the group of 125 selected breast carcinoma patients with broad spectrum of histological types and grades. Multivariate statistical analysis revealed only relationships between ER/PR, ER/Bcl-2, ER/grade and ER/age. There was not found any significant relationship between c-erbB-2 expression and any other immunohistochemical marker, apocrine metaplasia, histological type or patient characteristics. The same result was found in complete group of tumors as well as in individual groups divided according to histological type. These results indicate that in node negative breast tumors, c-erbB-2 expression does not correlate inversely with hormone receptor status and hormone responsiveness like previously reported metastasising breast cancer and that the prognostic significance of c-erbB-2 expression in these tumors is not clear.

Adult↗
PubMed2002

Nuclear receptors in early hormone refractory prostate cancer and their relationship to apoptosis-related proteins.

The expression of several genes involved in apoptosis and cell cycle control can be regulated by steroid hormones and related agents via their nuclear receptors. Members of the bcl-2 gene family participate in the regulation of apoptosis in a diverse range of cell types and are implicated in the development of hormone refractory prostate cancer and resistance to anti-cancer therapy. The aim of this study, therefore, was to examine the expression of several nuclear receptors in relation to the expression of apoptosis and cell cycle related proteins in a series of patients with early hormone refractory prostate cancer. Analysis of protein expression revealed only a weak association between Bcl-2 and AR. Bax positivity and p27Kip1 expression were significantly more frequent in the AR-positive tumors, whereas RXRbeta expression was more frequently observed in the AR-negative group. The expression of AR, Bax and p27Kip1 was inversely related, and the expression of RXRbeta directly related, to Gleason pattern status. These results suggest that the immunophenotype of early hormone refractory prostate cancer may be different to that seen in more advanced stage disease. Androgen withdrawal therapy employing anti-androgens may elicit different signalling pathways that may be dependent on ARstatus and ARsensitivity.

Apoptosis↗
PubMed2002

[What is the real importance of evaluating the expression of c-erbB-2 (HER-2/neu) in carcinoma of the breast and prostate? (A short review)].

This minireview covers the key data on biology and clinical implications of the c-erbB-2 oncogene in breast and prostate cancer. The aim was to provide basic information to practically oriented pathologists in order to make a reasonable application of methods for c-erbB-2 overexpression or amplification analysis. The clinical interpretation of c-erbB-2 abnormalities should reflect the complexity of c-erbB-2 mediated regulatory pathway and explain why tumours with overexpression/amplification of c-erbB-2 very often do not respond to therapy using Herceptin.

Antibodies, Monoclonal↗
PubMed2001

Apoptosis, analysed by means of lamin B detection, correlates with grade of astroglial tumours but not with p27Kip1/retinoblastoma protein expression.

The aim of our study was to correlate apoptosis, assessed by means of lamin B degradation, with grade of tumour and immunohistochemical expression of p27Kip1 and retinoblastoma protein (pRB) in a series of 32 low-grade astrocytomas (LGA) and 43 high-grade astrocytomas (HGA). Determination and analysis of lamin B expression was achieved stereologically with the use of computerised interactive image analysis. The average stereological surface density of the lamin-positive nuclear surface of cells showing evidence of lamin degradation cells was 13.80 mm2/mm3 in LGA and 21.02 mm2/mm3 in HGA. The average range of immunopositivity of p27 and pRB expression was 2.85 and 2.10, respectively, in LGA and 1.80 and 0.88, respectively, in HGA. The rate of apoptosis indirectly correlated with the expression of both p27 and pRB but was not fully significant (P < or = 0.09). Our findings suggest that there may be a loss of function of main cell-cycle regulators and increased uncontrolled cell death in addition to increased cell proliferation in high-grade astrocytomas. Moreover, we believe that the detection of lamin B degradation in astroglial tumours can be an alternative, precise and convenient assay for the detection of a defined set of apoptotic cells. However, before being applied more generally, comparative research should be done on different methods of quantifying apoptosis, with the intent of finding the difference between biologically different methods. Such studies would also be able to find the method associated with the strongest prognostic power.

Apoptosis↗