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Ferenc Sipos

Publications and source records attributed to Ferenc Sipos.

At least 19 recordsLinked to original sources
PubMed2006

mRNA expression, functional profiling and multivariate classification of colon biopsy specimen by cDNA overall glass microarray.

AIM: To understand the local pathophysiological alterations and gene ontology-based functional classification of colonic biopsies into inflammatory and neoplastic diseases. METHODS: Total RNA was extracted from frozen biopsies and amplified by T7-method. Expression profile was evaluated by Atlas Glass 1K microarrays. After microarray quality control, applicable data were available from 10 adenomas, 6 colorectal adenocarcinomas (CRCs), and 6 inflammatory bowel diseases (IBDs). Multivariate statistical and cell functional analyses were performed. Real-time RT-PCR and immunohistochemistry were used for validation. RESULTS: Discriminant analysis of selected genes, could correctly reclassify all 22 samples using 4 parameters (heat shock transcription factor-1, bystin-like, calgranulin-A, TRAIL receptor 3). IBD samples were characterized by overregulated chemokine (C-X-C motif) ligand 13, replication protein A1, E74-like factor 2 and downregulated TNF receptor-associated factor 6, BCL2-interacting killer genes. In adenomas upregulation of TNF receptor-associated factor 6, replication protein A1, E74-like factor 2 and underexpression of BCL2-associated X protein, calgranulin-A genes were found. CRC cases had significantly increased epidermal growth factor receptor, topoisomerase-1, v-jun, TNF receptor-associated factor 6 and TRAIL receptor 3, and decreased RAD51 and RAD52 DNA repair gene, protein phosphatase-2A and BCL2-interacting killer mRNA levels. Epidermal growth factor receptor RT-PCR and immunohistochemistry, topoisomerase-1 RT-PCR confirmed the chip results. CONCLUSION: Different histological alterations can be reclassified by functional, multivariate analysis using cDNA microarrays. Further studies with expanded sample number are needed for subclassification of pathological alterations.

Adenocarcinoma↗
PubMed2006

[Insulin-like growth factor receptor, hepatocyte-derived growth factor receptor and telomerase expression in ulcerative colitis].

BACKGROUND: The risk of colorectal carcinoma development is elevated in chronic, longstanding ulcerative colitis. The changes of such regenerative and immortalizing pathways caused by the inflammatory process that are proved to be carcinogenic in other human tissues have not been fully and uniformly described. Aim of the study was to describe the expression alterations of regenerative signal receptors and cell aging inhibitory systems within colonic crypts considering the histological activity of the disease. MATERIALS AND METHODS: I-type insulin-like growth factor receptor (IGF1R), hepatocyte derived growth factor receptor (HGFR), telomerase reverse transcriptase (TERT) and telomerase associated protein (TP-1) expression were evaluated immunohistochemically on formalin fixed paraffin embedded biopsy specimen from 10 mild, 10 moderate, and 10 severe active inflammation of ulcerative colitis and from 10 normal colonic tissue. RESULTS: In mild inflammation all observed parameter showed significantly elevated protein expression in protein level compared to normal (p <0.005). In moderately active inflammation only IGF1R expression was significantly higher compared to normal and to mild inflammation (p <0.005). There were no regenerative signal expression alteration in severe inflammation compared to normal, and epithelial telomerase expression was not detectable in these cases. CONCLUSION: The expression of regenerative signal receptors and immortalizing factors is elevated in mildly (and moderately) inflamed ulcerative colitis. This phenomenon let the genetically defected epithelial cells to pathologically survive and proliferate, so thus favours the development of tumors.

Adult↗
PubMed2006

Laser microdissection in translational and clinical research.

Laser microdissection (LMD) is now a well established method for isolating individual cells or subcellular structures from a heterogeneous cell population. In recent years, cell, DNA, RNA, and protein based techniques has been successfully coupled to LMD and important information has been gathered through the analysis of the genome, transcriptome, and more recently the proteome of individual microdissected cells. The aims of this review are to summarize and compare the principles of different laser microdissection instruments and techniques, to discuss sample preparation procedures for microdissection, and to provide wide variety of examples of translational/clinical research applications of LMD. Novel techniques specifically developed for the improved isolation of stained cells, living cells, or rare cells are also discussed.LMD has become an indispensable tool in the preparation of homogenous samples for sophisticated cell or molecular assays. Despite major technological advances, the labor requirements of LMD are still relatively high. However, understanding the advantages and disadvantages of LMD technology and associated sample preparation procedures may aid in the earlier introduction of this method into the routine clinical diagnostics.

Animals↗
PubMed2006

In vitro binding and functional studies of Ac-RYYRIK-ol and its derivatives, novel partial agonists of the nociceptin/orphanin F/Q receptor.

Following the discovery of nociceptin/orphanin FQ (N/OFQ) peptide receptor (NOP) and its endogenous ligand, an extensive search has started to find selective agonists and antagonists targeting this novel receptor-ligand system due to their therapeutic potentials. By the help of the combinatorial chemistry a series of hexapeptides with a general formula of Ac-RYY-R/K-W/I-R/K-NH(2) having high NOP receptor affinity and selectivity were identified. On the basis of this information we developed a number of novel compounds. The detailed structure-activity studies on the partial agonist Ac-RYYRIK-NH(2) are reported in this communication. Besides the modifications on N- and C-terminal, Arg-Cit exchange was performed on the template structure. The novel hexapeptides were analyzed in radioligand binding, functional biochemical [(35)S]GTPgammaS binding assays by using membranes from rat brains and Chinese hamster ovary cells expressing human NOP receptor. The agonist/antagonist properties were also tested on in the mouse vas deferens bioassay. C-terminal modification yielded a high affinity, selective and potent NOP ligand (Ac-RYYRIK-ol) with a partial agonist property. Several analogs of this compound were synthesized. The presence of the positively charged arginine residue at the first position turned out to be crucial for the biological activity of the hexapeptide. The N-terminal modifications with various acyl groups (ClAc, pivaloyl, formyl, benzoyl, mesyl) decreased the affinity of the ligand towards the receptor and the intrinsic activity for stimulating the G-protein activation was also decreased. The structure-activity studies on the hexapeptide derivatives provided some basic information on the structural requirements for receptor binding and activation.

Animals↗
PubMed2006

The half-and-half nail: a new sign of Crohn's disease? Report of four cases.

Systemic disease can produce changes in the nails. Perhaps the best known example of this is koilonychia as a sequale of iron deficiency anemia. "Half and half nail" is a type of pseudoleuconychia that can be caused by chronic renal disease, Kawasaki's disease, cirrhosis, and zinc deficiency. It has not been described in patients with Crohn's disease yet. Four male patients with Crohn's disease were observed. None of them had extraintestinal manifestations of Crohn's disease. The average duration of the disease was 5.25 (range, 1-10) years. The nail alterations were defined with a portion of the nail being as much as 15 to 40 percent of normal color distally, whereas the rest of the nail was white. The contrast between the two zones remains sharply demarcated even after constricting venous return. Histologic examination was not performed. Every patient had zinc deficiency but not hypalbuminaemia or sideropenia. After review of relevant literature (MEDLINE, PubMed, etc.), we found that half-and-half nail had not been described in Crohn's disease. This study was designed to highlight the fact that the half-and-half nail, which was thought to be a sign of chronic renal failure, also occurs in patients with Crohn's disease. The relationship of this symptom to clinical activity cannot yet be assessed and has only been observed in four cases.

Adult↗
PubMed2005

[Isolation and therapeutic use of human stem cells].

Nowadays, adult stem cells are the main target of biological research. Stem cell specific markers allow the extraction in enough quantity and high purity of multipotent cells from organic tissues, and their usage instead of the ethically reprehensible embryonal stem cells in experimental therapeutic purposes is also possible. The key point in the development of a new, stem-cell based therapeutic methodology is the determination of stem cell specific cell surface or cytoplasmatic antigens that makes reliable stem cell identification possible. Bone marrow derived multipotent stem cells can already be suitably identified, and other, more or less organic tissue-derived stem cell specific markers are also available. The first therapeutic interventions have been already done in diseases such as myocardial infarction or diabetes mellitus, and led to promising results.

Adult↗
PubMed2005

The results of the expression array studies correlate and enhance the known genetic basis of gastric and colorectal cancer.

Gastric and colorectal cancers belong to the most frequent cancer types in the world today. This fact emphasizes the importance of identification of useful diagnostic and prognostic markers, in the earliest stage of the disease. The examination of gene expression profile in gastric and colorectal cancer may develop the bases of early diagnosis and of individual therapeutic strategies. In the microarray examinations done so far for these types of cancers, the expression of hundreds and thousands of genes were studied, however, both the sample collection and the results showed wide variations. The diversity of expression array methods and data analysis makes the comparison of microarray results difficult. Beside the exposition of the practical aspects of the chip technology, our aims are the systematization of data that are currently available in the international scientific literature and the description of the results in a comprehensive way. Microarray results show that the gene expression pattern, detected in gastric and colon cancers, highly depends on the histological type and heterogeneity of the sample, array type, and softwares, used for data analysis. Recent experiments point out not just the changes of the alterations of tumor suppression, apoptosis, cell-cycle regulation, and signal transduction, but tumor cell metabolism and cell-microenvironment interactions also. Results show connection to and make more complete the already known molecular background of gastric and colorectal cancers. Based on the accumulation of recent and further data, such kind of multifunctional diagnostic microarrays that can be suited for completing the conventional histological diagnostics and subtypization will certainly become available in the near future.

Colorectal Neoplasms↗
PubMed2005

Isolation of epsilon-haemoglobin-chain positive fetal cells with micromanipulation for prenatal diagnosis.

OBJECTIVES: The isolation and analysis of fetal cells in maternal blood during pregnancy is under investigation as a means of noninvasive prenatal diagnosis. The aim of our study was to detect fetal gender from maternal peripherial blood samples during pregnancy with the detection and analysis of epsilon-haemoglobin-chain positive fetal nucleated red blood cells (NRBCs) collected by a micromanipulator. Here we report our first results. DESIGN AND METHODS: We obtained maternal blood from 14 singleton pregnancies. After a double density gradient separation, magnetic activated cell sorting was performed by positive selection for nucleated red blood cells with anti-CD71. With the help of this enrichment step, followed by immunophenotyping with an anti-haemoglobin-epsilon monoclonal antibody, the isolation of the epsilon haemoglobin chain positive cells with micromanipulation could be done. We performed single cell fluorescent PCR analysis of these cells; we used primers for the amelogenin gene to detect fetal gender. We compared our findings with the results of amniocentesis. RESULTS: Fetal gender was successfully determined in 11 out of 14 cases; among them, in 2 cases with Klinefelter syndrome (47,XXY). CONCLUSION: The results of our study suggest that micromanipulation and QF-PCR analysis of anti-haemoglobin-epsilon fluorescent antibody stained fetal cells from maternal blood can be useful in prenatal diagnosis to detect fetal gender and promising to be improved to detect chromosomal abnormalities.

Antigens, CD↗
PubMed2005

Growth in epithelial cell proliferation and apoptosis correlates specifically to the inflammation activity of inflammatory bowel diseases: ulcerative colitis shows specific p53- and EGFR expression alterations.

PURPOSE: Epithelial cell turnover related differences between ulcerative colitis, Crohn's colitis, and aspecific colitis are not known yet. METHODS: Totally 345 formalin-fixed, paraffin-embedded biopsy specimens from 33 ulcerative colitis, 26 Crohn's colitis, 30 aspecific colitis, and 10 healthy patients were observed with the TdT-mediated dUTP nick end labeling method and proliferating cell nuclear antigen-, p53-, and epithelial growth factor receptor immunohistochemistry. Because of epithelial growth factor receptor positivity of subepithelial cells epithelial growth factor receptor and CD45, CD68, or CD83 double fluorescence immunohistochemistry were performed on 16 freshly frozen samples from 8 severely active ulcerative colitis and 8 severely active Crohn's colitis patients to describe lamina propria's mononuclear cells, respectively. RESULTS: The epithelial growth factor receptor expression was significantly lower in each inflammatory group compared with normal (P < 0.005) and decreased significantly in mild ulcerative colitis compared with mild Crohn's colitis or aspecific colitis (P < 0.005). Numerous epithelial growth factor receptor and CD45 double-positive submucosal mononuclear cells were observed in moderate-severe inflammations. The p53-expression was significantly higher in each inflammatory group compared with normal (P < 0.05). Significant differences were found between mildly, moderately, and severely inflamed samples in ulcerative colitis (P < 0.05) compared with Crohn's colitis or aspecific colitis. Apoptotic/proliferative rates increased significantly in line with the inflammatory process (P < 0.0001/0.05), but the TdT-mediated dUTP nick end labeling and proliferating cell nuclear antigen-labeling characteristics did not show disease type specificity. CONCLUSIONS: Based on our results, the alterations of epithelial growth factor receptor and p53 expression show ulcerative colitis specificity, whereas the rate of epithelial apoptosis and proliferation are determined by the histologic activity of the inflammation. The increased epithelial growth factor receptor expression by the lamina propria's mononuclear cells in inflammation may suggest its role as an autoantigen.

Apoptosis↗
PubMed2004

[First attempts of detecting fetal cells in the maternal circulation].

INTRODUCTION: In prenatal diagnosis there is great interest for noninvasive diagnostic methods. Authors report their first results in detecting fetal cells in the maternal circulation during pregnancy. OBJECTIVE: The aim of the study was to detect fetal gender from maternal peripheral blood samples during pregnancy. METHOD: Authors have analysed fetal nucleated red blood cells. In 12 cases after a double density Percoll gradient separation they labelled the surface antigens of the cells with anti-glycophorin-A and anti-CD45 fluorescent antibodies, did an intracellular staining of the epsilon haemoglobin chain, and analysed the cells with flow cytometry. The CD45 negative/glycophorin-A positive/epsilon-haemoglobin chain positive cells were considered as fetal cells. Having the results, in another 13 cases magnetic activated cell sorting with CD71 antibody were used as an enrichment step. Authors made an intracellular staining of the epsilon haemoglobin chain, the positive cells were isolated by micromanipulation, and analysed by single cell fluorescent polymerase chain reaction. Primers for the amelogenin gene were used to detect fetal gender. RESULTS: Only the Percoll enrichment step itself is not enough for using the samples for diagnostic molecular-biologic examinations, a following enrichment step is needed. For this the authors used magnetic activated cell sorting with CD71 antibody. With the help of this enrichment step, after the intracellular staining of the epsilon haemoglobin chain the direct micromanipulator isolation of the epsilon haemoglobin chain positive cells could be done. After analysing single cells by fluorescent polymerase chain reaction, in 8 out of the 11 comparable cases the results were similar to those, what was found during the genetic amniocentesis. In 2 cases from this 8, genetic amniocentesis proved Klinefelter syndrome, which they could also confirm with the examination of fetal cells in the maternal circulation. CONCLUSION: The results of the study suggest that the method described above can be useful in prenatal genetic diagnosis, and improving it could be useful to detect other genetic abnormalities (chromosomal abnormalities, single gene disorders) as well.

Antigens, CD↗
PubMed2004

[The importance and use of laser microdissection in clinical research and diagnostic method development].

The molecular biological analysis of rare cell samples has become increasingly important in medical research and applications. Using laser microdissection and special macromolecule isolation techniques allows us to understand the biological information even in a single cell and to examine the genetical and proteomical features of biologically homogenous cell populations. There are several type of laser microdissectors which have a very user-friendly actuation. In practice the most difficult parts are the sample preparation and the macromolecule extraction from rare cell samples. The aims of this study are to summarize current practical experiences and to foreshow the application possibilities of this quite new technique in clinical practice.

Animals↗
PubMed2004

[Use of DNA-chips technology in colorectal cancer].

The examination of gene expression in colorectal cancer may develop the bases of early diagnosis and of individual therapeutic strategies. With the few cDNA microarray examinations in colorectal cancer the expression of hundreds and thousands of genes were studied, although both the sample collection and the final results showed differences. Beside the exposition of the practical advantages of the chip technology our aims are the standardization of the currently available data in the international scientific literature and the description of the results in a comprehensible way. To summarize one can say that gene expression examinations in colorectal cancer show the accentuated role in carcinogenesis of not only the tumor suppressor, apoptosis- or cell-cycle regulation related genes, but of some mitochondrial, metabolic and cell-cell or cell-extracellular matrix conjunction gene families.

Colorectal Neoplasms↗
PubMed2004

[Necessity of chip technology in stomach cancer].

Gastric cancer is one of the most frequent cancer type in the world today. This fact emphasises the importance of identification of useful diagnostic and prognostic markers for gastric cancers in their earliest stages. Aim of this review is to summarize the genetic knowledge related to gastric carcinogenesis and progression and to offer a survey of the gene expression pattern changes and their functional classification. Microarray results show that the gene expression pattern detected in gastric cancers highly depends on the histological type and heterogeneity of the sample, array type and data analyzing softwares. Recent experiments point out the changes of not just the alterations of tumor suppression, apoptosis, cell cycle regulation and signal transduction, but tumor cell metabolism and cell-microenvironment interactions, too. All results show connection to and complete the already known molecular background of gastric cancer.

Adenocarcinoma↗
PubMed2004

Scanning fluorescent microscopy is an alternative for quantitative fluorescent cell analysis.

BACKGROUND: Fluorescent measurements on cells are performed today with FCM and laser scanning cytometry. The scientific community dealing with quantitative cell analysis would benefit from the development of a new digital multichannel and virtual microscopy based scanning fluorescent microscopy technology and from its evaluation on routine standardized fluorescent beads and clinical specimens. METHODS: We applied a commercial motorized fluorescent microscope system. The scanning was done at 20 x (0.5 NA) magnification, on three channels (Rhodamine, FITC, Hoechst). The SFM (scanning fluorescent microscopy) software included the following features: scanning area, exposure time, and channel definition, autofocused scanning, densitometric and morphometric cellular feature determination, gating on scatterplots and frequency histograms, and preparation of galleries of the gated cells. For the calibration and standardization Immuno-Brite beads were used. RESULTS: With application of shading compensation, the CV of fluorescence of the beads decreased from 24.3% to 3.9%. Standard JPEG image compression until 1:150 resulted in no significant change. The change of focus influenced the CV significantly only after +/-5 microm error. CONCLUSIONS: SFM is a valuable method for the evaluation of fluorescently labeled cells.

Fluorescent Dyes↗
PubMed2004

Scanning fluorescent microscopy analysis is applicable for absolute and relative cell frequency determinations.

BACKGROUND: Flow cytometry (FCM) and laser scanning cytometry (LSC) are the routine techniques for fluorescent cell analysis. Recently, we developed a scanning fluorescent microscopy (SFM) technique. This study compares SFM to LSC (two slide-based cytometry, SBC, techniques) and FCM, in experimental and clinical settings. METHODS: For the relative cell-frequency determinations, HT29 colorectal cancer cells and Ficoll separated blood mononuclear cells (FSBMCs) were serially diluted (from 1:1 to 1:1,000) and measured by each of the three techniques. For the absolute cell number determinations (only for SBC) FSBMCs were smeared on slides, then HT29 cells were placed on the slide with a micromanipulator (5-50 cells). Tumor cells circulating in the peripheral blood were isolated by magnetic separation from clinical blood samples of colorectal cancer patients. All samples were double-stained by CD45 ECD and CAM5.2 FITC antibodies. For slides, TOTO-3 and Hoechst 33258 DNA dyes were applied as nuclear counter staining. RESULTS: In the relative cell frequency determinations, the correlations between the calculated value and measured values by SFM, LSC, and FCM were r(2) = 0.79, 0.62, and 0.84, respectively (for all P < 0.01). In the absolute cell frequency determinations, SFM and LSC correlated to a high degree (r(2) = 0.97; P < 0.01). CONCLUSIONS: SFM proved to be a reliable alternative method, providing results comparable to LSC and FCM. SBC proved to be more suitable for rare-cell detection than FCM. SFM with digital slides may prove an acceptable adaptation of conventional fluorescent microscopes in order to perform rare-cell detection.

Antiporters↗
PubMed2003

[Possibilities of investigation and clinical application of adult human stem cells].

Multipotent adult tissue stem cells have high plasticity and transdifferentiation ability. The stem cell therapy can be the solution of curing many severe diseases such as osteogenesis imperfecta, hepatic failure, heart muscle damage after myocardial infarction, I-type diabetes, variety of central nervous system disorders such as brain injury, stroke, Parkinson's disease and other neurodegenerative disorders. Isolation of certain types of stem cells is solved nowadays, but low frequency of these cells and lack of special identification markers make their isolation and search more difficult. The more and more developed in vitro cell culture technologies, the widespread macromolecule amplification and examination techniques of molecular biology and the gene technology tools for genetic modification of stem (and other) cells contribute to research and therapeutic applications of stem cells. Transfer of new genetic material to stem cells and expression of the gene product in daughter cells--because missing or damaged genes can be replaced--is an exiting approach of the treatment of congenital (enzyme deficiencies) and acquired human diseases (cancers).

Adult↗
PubMed2003

Molecular detection of circulating cancer cells. Role in diagnosis, prognosis and follow-up of colon cancer patients.

BACKGROUND: The circulating tumor cells of solid tumors, especially in colorectal cancer has been of great interest in medical research in the last and new century. METHODS: A literature review of recent data for the preparation of a proposal for clinical applications. RESULTS: Starting with the detection of circulating cancer cells in histological sections, lymph nodes, bone marrow and peripheral blood have recently become the primary samples for these investigations. Following microscopic morphology, new methods were and are being developed continuously including rare cell enrichment and detection techniques like fluorescence microscopy, flow cytometry, RT-PCR and methylated DNA PCR. The sensitivity of these assays reaches down to the concentration of 1 tumor cell/ml blood. A lot of different epithelial markers were targeted with these techniques e.g. cytokeratins, EGFR, CEA, and EMA. Clinically, circulating tumor cells were found as independent prognostic factors in lymph nodes and bone marrow. In blood, their presence appears to be an early marker for recurrence and relapse. The change in their quantitative number is supposed to reflect the chemotherapeutic sensitivity and metastatic growth activity of the tumor. CONCLUSIONS: The detection of circulating tumor cells in bone marrow and lymph nodes is of clinical significance. Their presence in peripheral blood and therapeutic applications need further clarification.

Biomarkers, Tumor↗