Biomedical subjects

Orsolya Galamb

Publications and source records attributed to Orsolya Galamb.

12 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

Use of routinely collected amniotic fluid for whole-genome expression analysis of polygenic disorders.

BACKGROUND: Neural tube defects related to polygenic disorders are the second most common birth defects in the world, but no molecular biologic tests are available to analyze the genes involved in the pathomechanism of these disorders. We explored the use of routinely collected amniotic fluid to characterize the differential gene expression profiles of polygenic disorders. METHODS: We used oligonucleotide microarrays to analyze amniotic fluid samples obtained from pregnant women carrying fetuses with neural tube defects diagnosed during ultrasound examination. The control samples were obtained from pregnant women who underwent routine genetic amniocentesis because of advanced maternal age (>35 years). We also investigated specific folate-related genes because maternal periconceptional folic acid supplementation has been found to have a protective effect with respect to neural tube defects. RESULTS: Fetal mRNA from amniocytes was successfully isolated, amplified, labeled, and hybridized to whole-genome transcript arrays. We detected differential gene expression profiles between cases and controls. Highlighted genes such as SLA, LST1, and BENE might be important in the development of neural tube defects. None of the specific folate-related genes were in the top 100 associated transcripts. CONCLUSIONS: This pilot study demonstrated that a routinely collected amount of amniotic fluid (as small as 6 mL) can provide sufficient RNA to successfully hybridize to expression arrays. Analysis of the differences in fetal gene expressions might help us decipher the complex genetic background of polygenic disorders.

Amniotic Fluid↗

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

[Molecular biology background of inflammatory bowel disease].

The exact pathological background of inflammatory bowel disease has not been clarified yet. Many aspects of genetical and environmental factors, as well as certain alterations of the functions of epithelial cells and immunoregulation which may attenuate chronic inflammation in the gastrointestinal tract are known. These three components have many connecting points. Among the inflammatory bowel disease genes we know only the function of the NOD2/CARD gene, and we have some idea about the OCTN and DRG genes. The function of the intestinal epithelial cells is changed in inflammatory bowel disease. The latter two genes may have a role in the increased permeability, so as the tumor necrosis factor alpha, interferon gamma may play affect it. The interleukin-10 helps the mucosal integrity. The interleukin-6 production is elevated in these diseases, and the interleukin-8 level can be elevated in case of mutation of toll like receptor 5. The tumor necrosis factor alpha, interferon gamma and lymphotoxin-3-alpha increased the chemokine secretion and adhesion molecule expression also. The amount of certain cytokines are changed in inflammatory bowel disease. There were no association between the incidence and phenotype of Crohn's disease and cytokine gene polymorphisms, except the interleukin 6 gene. It seems that these alterations are secondary, and don't play a major role in the pathogenesis of inflammatory bowel disease.

Crohn Disease↗

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↗

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↗

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

[Immunobiology of dendritic cells and their application in clinical practice].

INTRODUCTION: Dendritic cells play a central role in the regulation of the immune responses towards cellular or humoral immunity. Several types of dendritic cells can be distinguished, which originate from different hematopoietic lineages, and differ from each other in function, morphology and localization within the organism. Immature dendritic cell-precursors originate from bone marrow haemopoietic stem cells, circulate in blood system and reach peripheral tissues, where they differentiate into active antigen capturing and processing cells. They have further maturation by the effect of adequate signals (antigen stimuli and inflammatory cytokines) and migrate into secondary lymphoid organs, presented cell surface MHC molecules-linked peptides from antigens which they have captured and processed, to T lymphocytes, induce immune reaction by T cell activation. Apart from the fact that dendritic cells as professional antigen presenting cells are essential to induction T cell-mediated immune responses, they influence activation and function of B lymphocytes and effector cells of natural immune system by cytokines and cell-cell interactions. CONCLUSIONS: Complex regulatory function of dendritic cells make a possibility for artificial alteration of immune processes by modification of dendritic cells: direct against definitive antigens, increase or decrease their intensity, hereby we can accomplish the immunotherapy of different diseases such as tumors, infection, autoimmune diseases, transplants' rejection.

Antigen Presentation↗

PubMed2003

[DNA chips for gene expression analysis and their application in diagnostics].

Due to large genome projects more and more genetic information and more and more data about genetic background of various diseases can be obtained. By means of microarrays thousands to hundreds of thousands of molecular analysis can be performed at a time, rapidly, under identical conditions, hereby microarrays provide a solution to continuously increasing throughput demands from large genomic, pharmacogenetic and proteomic programmes. Microarrays offer unprecedented opportunities for qualitative and quantitative analysis of gene expression, understanding gene function and detection gene alterations, polimorphisms. Microarray expression profiles will define stages of different tumor types and new prognostic subgroups in cancer and other diseases. For individual patients, more precise diagnosis and risk assessment based on expression profiles are already achievable, leading to more accurate determination of prognosis and more individually tailored treatment. Microarrays will play an important role in diagnostics of infectious diseases and identification of novel diagnostic and therapeutic targets. Wide-spread application of microarrays in clinical practice is not typical today, but their production on an industrial scale and the increased information provided by microarrays should assure their entry into clinical practice as very powerful, sensitive, specific and rapid tools of diagnostics of various diseases.

Communicable Diseases↗

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↗