Kristina Yeghiazaryan
University of Bonn
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Publication
Featured researches published by Kristina Yeghiazaryan.
The Epma Journal | 2013
Olga Golubnitschaja; Kristina Yeghiazaryan; Vincenzo Costigliola; Daniela Trog; Michael Braun; Manuel Debald; Walther Kuhn; Hans H. Schild
Breast cancer is a multifactorial disease. A spectrum of internal and external factors contributes to the disease promotion such as a genetic predisposition, chronic inflammatory processes, exposure to toxic compounds, abundant stress factors, a shift-worker job, etc. The cumulative effects lead to high incidence of breast cancer in populations worldwide. Breast cancer in the USA is currently registered with the highest incidence rates amongst all cancer related patient cohorts. Currently applied diagnostic approaches are frequently unable to recognise early stages in tumour development that impairs individual outcomes. Early diagnosis has been demonstrated to be highly beneficial for significantly enhanced therapy efficacy and possibly full recovery. Actual paper shows that the elaboration of an integrative diagnostic approach combining several levels of examinations creates a robust platform for the reliable risk assessment, targeted preventive measures and more effective treatments tailored to the person in the overall task of breast cancer management. The levels of examinations are proposed, and innovative technological approaches are described in the paper. The absolute necessity to create individual patient profiles and extended medical records is justified for the utilising by routine medical services. Expert recommendations are provided to promote further developments in the field.
The Epma Journal | 2010
Kristina Yeghiazaryan; Josef Flammer; Olga Golubnitschaja
Paradigm change from late interventional approach to predictive diagnostics followed by targeted prevention before manifest pathology, presents innovative concept for advanced healthcare. Preselection of healthy but pathology-predisposed individuals is the primary task in the overall action. Vasospasm is a frequent syndrome defined as an inappropriate constriction or insufficient dilatation in microcirculation. Vasospastic individuals are considered as healthy subpopulation predisposed to several pathologies including neurodegeneration. Clinical observations, subcellular imaging and “gene hunting”-investigations provide evidence for vasospasm as predisposition to glaucoma; development of further related pathologies cannot be excluded. Predictive molecular-profiling in blood can specify individual predisposition for effective prevention.
The Epma Journal | 2011
Olga Golubnitschaja; Kristina Yeghiazaryan; Melanie Cebioglu; Micaela Morelli; Mario Herrera-Marschitz
Perinatal Asphyxia—oxygen deficit at delivery—can lead to severe hypoxic ischaemic organ damage in newborns followed by a fatal outcome or severe life-long pathologies. The severe insults often cause neurodegenerative diseases, mental retardation and epilepsies. The mild insults lead to so-called “minimal brain-damage disorders” such as attention deficits and hyperactivity, but can also be associated with the development of schizophrenia and life-long functional psychotic syndromes. Asphyxia followed by re-oxygenation can potentially lead to development of several neurodegenerative pathologies, diabetes type 2 and cancer. The task of individual prediction, targeted prevention and personalised treatments before a manifestation of the life-long chronic pathologies usually developed by newborns with asphyxic deficits, should be given the extraordinary priority in neonatology and paediatrics. Socio-economical impacts of educational measures and advanced strategies in development of robust diagnostic approaches targeted at effected molecular pathways, biomarker-candidates and potential drug-targets for tailored treatments are reviewed in the paper.
The Epma Journal | 2010
Babitha George; Melanie Cebioglu; Kristina Yeghiazaryan
Diabetes mellitus (DM) is a lifelong progressive disease. Currently there are more than 285 million DM-affected people worldwide. Globally the prevalence of diabetes continues to rise and is more pronounced in countries with large populations such as China, India and USA. Driving forces behind the epidemic are obesity, aging of the population and longer life expency. Prospective, the majority of diabetic population will be in their six to eight decades of life with the implication of more females than males. Severe micro- and macrovascular complications associated with diabetes lead to a highly increased morbidity and mortality. Therefore, DM is projected to be one of the leading health problems of 21st centuary. Urgent measures are required to reduce the diabetic burden. Thus advanced predictive diagnostic tools and personalized treatment strategies in (pre)diabetic care are critical and should exert beneficial impact on public health.
The Epma Journal | 2010
Olga Golubnitschaja; Kristina Yeghiazaryan; Josef Flammer
Prediction and prevention of glaucoma. Neurodegenerative eye disease glaucoma is the second leading cause of blindness with estimated 67 million patients worldwide. Molecular pathomechanisms of glaucoma demonstrate both a considerable overlap with and remarkable particularities compared to other neurodegenerative disorders e.g. Alzheimer’s disease. Identification of pathology-specific biomarker-sets is essential to develop advanced diagnostic approaches and personalised patients’ treatment. Subcellular imaging and expression patterns in blood as the reliable platform for early/predictive glaucoma diagnosis. Following key pathways are affected in glaucoma pathology: stress response, apoptosis and DNA-repair, adhesion, blood-brain-barrier-breakdown, tissue remodelling, transcription regulation, multidrug resistance and energy metabolism.
Brain Research | 1998
Olga Labudova; Susanne Fang-Kircher; N. Cairns; Heike Moenkemann; Kristina Yeghiazaryan; Gert Lubec
Performing gene hunting in Down Syndrome fetal brain we detected an overexpressed sequence highly homologous to the human vasopressin gene. As this neuropeptide may be involved in the pathogenetic mechanism and, moreover, was described to play a role in memory and learning, we decided to study the brain gene product level in Down Syndrome (DS), controls and patients with Alzheimers disease (AD). Subtractive hybridization was used to study the differential expression between steady state mRNA levels in fetal brain of DS and controls at the 23rd week of gestation. A radioimmunological method was used to determine vasopressin (AVP) in five brain regions of each 9 aged DS brains, 9 brains with AD and 9 control individuals, obtained from brain bank. An overexpressed nucleic acid sequence with 91% homology to the vasopressin gene was detected in both fetal brains with DS. AVP levels in controls were of the order cerebellum>occipital>frontal>parietal>temporal lobe and were significantly higher in temporal lobe and lower in cerebellum of patients with DS. AVP levels in brain of AD patients were also significantly increased in temporal lobe but were not reduced in cerebellum. The biological meaning of increased AVP remain unclear but may be linked to the neurodegenerative processes, proposed to be similar in both disorders. Data from gene hunting in fetal DS brain along with our data on aged DS and AD patients suggest the early involvement of AVP in the pathomechanism accompanying cholinergic, monoaminergic and neuropeptidergic deficits described in DS and AD.
Amino Acids | 2008
Daniela Trog; Kristina Yeghiazaryan; Hans H. Schild; Olga Golubnitschaja
Nervous system tumors are one of the leading causes of cancer related death. Specific mechanisms facilitating the invasive behavior of gliomas remain obscure. Advanced simulation models of the in vivo response to therapy conditions should potentially improve malignant glioma treatment. Expressional profiling of vimentin––one of reliable pro-invasive tumor makers––in those simulation models was the goal of this study, in order to estimate a pro-invasive response of surviving malignant glioma cells under clinically relevant therapeutic conditions. Human U87-MG malignant glioma cells were used. These cells are characterized by the wild p53-phenotype, which is relevant for the majority of primary malignant glioblastomas. Experimental design foresaw the cells to undergo either irradiation or chemo-treatment with temozolomide alone, or combined treatment. Expression profiling of vimentin was performed by quantitative “Real-Time”-PCR under all treatment conditions simulating diverse tumor regions. Here we demonstrated that vimentin expression patterns in human malignant glioma cells strongly depend on cellular density, algorithms of drug delivery and chemo/radio treatment. Substantial differences were recognized between immediate and late therapy effects. Significant increase in vimentin expression levels was detected particularly in low-density cell cultures under durable treatment with constant concentration levels of temezolomide. Simulation of variable intratumoral regional conditions (central intratumoral regions vs. disseminated malignant cells in peripheral regions) demonstrated differential response of vimentin expression in malignant glioma cell cultures treated under clinically relevant conditions. Slight ebbing of expression levels as late effects of the treatment in confluent cultures may correspond to necrotic processes clinically observed in central intratumoral regions. Contrary, in disseminated malignant cells of peripheral regions therapy resulted in vimentin-inducing effects. This is in agreement with the clinical observations of an increased aggressiveness and malignancy grade of post-operatively chemo/radio-treated malignant gliomas.
Amino Acids | 2007
Kristina Yeghiazaryan; Dirk Skowasch; Gerhard Bauriedel; H. H. Schild; Olga Golubnitschaja
Summary.Objectives. Aortic stenosis is the leading cause of heart valve disease in elderly. Little is known about molecular mechanisms leading to altered left ventricular geometry generally and, particularly, to remodeling of degenerating aortic valve. Alterations in native degenerating aortic valves and valvular tissue after replacement might result from a stage specific tissue remodeling protein core induced by stress responsible factors. Here we were looking for a possible stage specificity of tissue remodeling and stress responsive checkpoint gene activation in native degenerating human aortic valves and bioprosthetic valvular tissue after replacement. Materials and methods. Specimens of native degenerating aortic valves as well as bioprosthetic valves after replacement were tested for their morphological properties. Native degenerating valves were selected for two groups: non-calcified (7 samples) and calcified (5 samples) one; the third group (5 samples) was consisting of bioprosthetic valve samples after replacement. Individual mRNA-pools were isolated from each tissue sample, and semi-quantitative RT-PCR was performed. Target transcripts of p21waf1/cip1, MT1-MMP, MMP-2, MMP-9 and TIMP-1 were measured. The specificity was controlled by restriction analysis of PCR products. Results and conclusions. According to the abundant expression of p21waf1/cip1, a highly activated stress response was found in non-calcified native degenerating aortic valves, whereas no stress response was monitored in valvular tissue after replacement. Whereas MT1-MMP expression was almost equally induced in all three groups investigated, MMP-9 was higher expressed in non-calcified versus calcified native valves, and was not expressed after replacement. An induced expression of MMP-2 was detected in non-calcified native degenerating aortic valves only. An abundant expression of tissue inhibitor of metalloproteinases TIMP-1 was observed in all three groups tested. Apparently, the ECM degradation potential is specifically enhanced in non-calcified native degenerating aortic valves e.g. at the early degeneration stages. In contrast, the replaced valves were found to be actively resorbing tissue with no detectable stress response, where both MT1-MMP and TIMP-1 might play the key role in geometry remodeling.
Proteomics Clinical Applications | 2007
Olga Golubnitschaja; Kristina Yeghiazaryan; K. Wunderlich; Hans H. Schild; Josef Flammer
Glaucomatous damage is a neurodegenerative eye disease and one of the leading causes of blindness with 67 million patients worldwide. Major currently challenging questions include early diagnosis, risk evaluation, and follow‐up. Circulating leukocytes have been demonstrated as potentially important source of disease specific markers. The relevance of expression alterations in leukocytes for glaucomatous damage needs to be clarified. Noteworthy, gene expression patterns of trabecular meshwork and Schlemms canal, which are anatomically and functionally highly relevant for glaucoma pathology, were shown to be similar to those of circulating leukocytes. Here, we report extensive alterations in characteristic protein expression patterns of circulating leukocytes for Normal‐Tension and Primary Open‐Angle Glaucoma, as revealed by analysis of 2‐D PAGE images. Among most conservative alterations we found the protein spot identified by MALDI‐TOF as basic transcription factor activating protein‐2beta (AP‐2β). Western‐blot analysis demonstrated significantly increased protein expression rates of AP‐2β in both Normal‐Tension and Primary Open‐Angle Glaucoma versus controls. AP proteins are essential factors of the basic transcription regulation; AP‐2 proteins play a decisive role, particularly, in morphogenesis of eye. Conservative AP‐2 up‐regulation is of special importance in terms of basic transcriptional dysregulation that might be specific for glaucoma disease.
Amino Acids | 2005
Olga Golubnitschaja; A. Jaksche; Heike Moenkemann; Kristina Yeghiazaryan; S.E. Karl; Daniela Trog; H. H. Schild; K. U. Löffler
Summary.Objective: The deposition of advanced glycation end products is enhanced in Diabetes mellitus (DM) and has been linked to diabetic complications such as a microvascular disease. Glycated proteins have receptors on mononuclear blood cells (MBCs) and have been shown to generate reactive oxygen species altering gene expression and modifying cellular targets, such as endothelial cells. Retinal angiopathy is a frequently observed microvascular complication in DM-patients. Because of the central role of activated MBCs, we hypothesised a functional link between specific alterations in gene expression of MBCs, an increased activity of matrix proteases in serum, and the extent of retinal angiopathy in DM.Material and methods: An appearance and proliferation index of diabetic retinopathy was evaluated in 38 DM-patients using fluorescein angiography. Alterations of gene transcription levels in MBCs were investigated using hybridisation of individual mRNA-pools to Atlas Array with a concomitant quantification of specific cDNAs by “Real-Time”-PCR. The activity of matrix metalloproteinases MMP-2 and MMP-9 in individual serum samples was measured by zymography combined with densitometric imaging system.Results and conclusions: Hybridisation to Atlas Array of mRNA-pools isolated from MBCs revealed an enhanced expression of recoverin in DM-patients compared to the control group. “Real-Time”-PCR showed the highest recoverin levels in the DM-subgroup with a high proliferation index. MMP-2 activity was highly increased in 36% of all patients, and in 44, 44, and 19% of patients with proliferative retinopathy, advanced proliferative retinopathy, and no detectable proliferation respectively. In those 3 groups MMP-9 activity was highly increased in 56, 67, and 31% of patients respectively, and in 44% of all DM-patients. In contrast to patients with active proliferation, the simultaneous high activation of all three genes was not observed in patients without active proliferation. The ex vivo molecular imaging system developed in this work may be helpful for the prediction of active proliferative retinopathy in DM.