In vitro - investigations of the influence of altered gene expression of the TGF-β-binding protein LTBP-4 on the expression pattern of the tumorsuppressive CDKIs

Deckblatt-Impressum persönlicher Dank Abkürzungen Inhaltsverzeichnis Einleitung Literaturübersicht Material und Methoden Ergebnisse Diskussion Zusammenfassung Summary Literaturverzeichnis Anhang Danksagung SelbständigkeitserklärungDie Expression von Genen, die Zellwachstum und -proliferation regulieren, ist bei Krebserkrankungen verändert oder mutiert und führt zu unkontrollierter Zellzyklus-Progression. Zu den potentesten Wachstumsregulatoren zählen sowohl TGF-β1 als auch p21 und c-myc. TGF-β1 (Transforming Growth Factor beta 1) reguliert in Assoziation mit seinem Bindungsprotein sLTBP-4 (»short form« des Latent TGF-β Binding Protein 4), das als wichtigster Modulator der TGF-β1-Bioverfügbarkeit gilt, verschiedenste Funktionen in epithelialen Zellen, wobei seine antiproliferative und somit tumorsuppressive Wirkung eine Hauptfunktion darstellt. Ein Mangel an TGF-β1 führt sowohl zu einer reduzierten Expression des tumorsuppressiven CDKI (Cyclin-abhängigen Kinaseinhibitoren) p21, als auch zu einer vermehrten Expression des Protoonkogens c-myc. Beide Mechanismen bedingen sich gegenseitig, sind somit prokanzerogen und induzieren eine verstärkte und ungehemmte Proliferation epithelialer Zellen. In einem in vitro-Modell mit der epithelialen Zelllinie HEK293T wurde in der vorliegenden Arbeit mittels quantitativer Expressionsanalyse untersucht, inwiefern p21 und c-myc in Zellen mit einer modulierten LTBP-4-Expression einer differentiellen Expression unterliegen. Ziel war hierbei das nähere Verständnis der Korrelation des TGF-β1-Bindungsproteins LTBP-4 mit dem CDKI p21 und dem Protoonkogen c-myc in der Karzinogenese epithelialer Zellen. Im Rahmen der molekularbiologischen Untersuchungen wurde zunächst das Genesilencing sowie die Überexpression des sLTBP-4-Gens in HEK293T-Zellen etabliert. Die Ergebnisse der proteinbiochemischen Untersuchungen ergänzten auf qualitativer Basis den molekularbiologischen, quantitativen Nachweis einer erfolgreichen sLTBP-4-Überexpression in HEK293T Zellen. In diesen Zellen wurde das sL4-V5-Fusionsprotein regelmäßig detektiert, was eine erfolgreiche Translation dokumentiert. In den folgenden qPCR-Analysen unterlagen die Gene TGF-β1, p21 und c-myc im vorliegenden in vitro - Modell des sLTBP-4-knock-down entgegen den Erwartungen keiner Expressionsregulation. In sLTBP-4-überexprimierten Zellen wurde eine vermehrte Genexpression von TGF-β1 und p21 sowie eine verminderte c-myc-Expression wie erwartet festgestellt. Die Ergebnisse zeigen somit eine Wechselbeziehung der untersuchten Zielgene im sLTBP-4-Überexpressionsmodell und verdeutlichen deren Expressionskorrelation in der Karzinogenese epithelialer Tumoren.The expression of genes regulating cell growth and proliferation, such as TGF-β1, p21, and c-myc, can be altered or modified in the process of carcinogenesis in epithelial tumors and therefore results in uncontrolled cell cycle progression. TGF-β1 (transforming growth factor beta 1) in association to its binding protein sLTBP-4 (»short form« of latent TGF-β binding protein 4) which is an important modulator of TGF-β1-bioavailability regulates different functions in epithelial cells. Its antiproliferative and therefore tumorsuppressive effects represent a major cellular function. A reduced availability of TGF-β1 results in reduced expression of tumorsuppressive CDKI`s (cyclin dependent kinase inhibitors), in particular p21, as well as in augmented expression of protooncogenes, in particular c-myc. Both mechanisms depend on each other, are procancerogenic and induce enhanced and unarrested proliferation of epithelial cells. In the present project it was analyzed using an in vitro model with the epithelial cell line HEK293T, wether p21 and c-myc in cells with altered LTBP-4-expression undergo a differential expression pattern themselves. The aim of this project was to get a closer insight into the correlation of the TGF-β binding protein LTBP-4 with the CDKI p21 and the protooncogene c-myc during the carcinogenic process of epithelial cells. Gene silencing as well as transient overexpression of the sLTBP-4-gene in HEK293T cells was established under in vitro conditions. The quantitative molecular biological proof of sLTBP-4 overexpression in HEK293T cells through qPCR inquisition was supported by western blot analysis. These proteinbiochemical investigations completed the qPCR survey on a qualitative basis. The sL4-V5 fusion protein was regularly detected, which documents a successful translation. The following qPCR analysis showed contrary to the expectations that there was no regulation of expression of the genes TGF-β1, p21, and c-myc in the model of sLTBP-4-knock-down. Further on it was expected to detect an enhanced gene expression of TGF-β1 and p21, as well as a reduced expression of c-myc in sLTBP-4-overexpressed cells. In this case the analysis showed an upregulation of TGF-β1- as well as p21-expression and a slightly reduced expression of the c-myc-gene. The results of this study indicate a correlation of the tested target genes in the model of sLTBP-4-overexpression and clarify their interdependency in the process of carcinogenesis in epithelial neoplasia

Summarization from Medical Documents: A Survey

Objective: The aim of this paper is to survey the recent work in medical documents summarization. Background: During the last decade, documents summarization got increasing attention by the AI research community. More recently it also attracted the interest of the medical research community as well, due to the enormous growth of information that is available to the physicians and researchers in medicine, through the large and growing number of published journals, conference proceedings, medical sites and portals on the World Wide Web, electronic medical records, etc. Methodology: This survey gives first a general background on documents summarization, presenting the factors that summarization depends upon, discussing evaluation issues and describing briefly the various types of summarization techniques. It then examines the characteristics of the medical domain through the different types of medical documents. Finally, it presents and discusses the summarization techniques used so far in the medical domain, referring to the corresponding systems and their characteristics. Discussion and conclusions: The paper discusses thoroughly the promising paths for future research in medical documents summarization. It mainly focuses on the issue of scaling to large collections of documents in various languages and from different media, on personalization issues, on portability to new sub-domains, and on the integration of summarization technology in practical applicationsComment: 21 pages, 4 table

Development and validation of a complementary map to enhance the existing 1998 to 2008 Abbreviated Injury Scale map

INTRODUCTION: Many trauma registries have used the Abbreviated Injury Scale 1990 Revision Update 98 (AIS98) to classify injuries. In the current AIS version (Abbreviated Injury Scale 2005 Update 2008 - AIS08), injury classification and specificity differ substantially from AIS98, and the mapping tools provided in the AIS08 dictionary are incomplete. As a result, data from different AIS versions cannot currently be compared. The aim of this study was to develop an additional AIS98 to AIS08 mapping tool to complement the current AIS dictionary map, and then to evaluate the completed map (produced by combining these two maps) using double-coded data. The value of additional information provided by free text descriptions accompanying assigned codes was also assessed. METHODS: Using a modified Delphi process, a panel of expert AIS coders established plausible AIS08 equivalents for the 153 AIS98 codes which currently have no AIS08 map. A series of major trauma patients whose injuries had been double-coded in AIS98 and AIS08 was used to assess the maps; both of the AIS datasets had already been mapped to another AIS version using the AIS dictionary maps. Following application of the completed (enhanced) map with or without free text evaluation, up to six AIS codes were available for each injury. Datasets were assessed for agreement in injury severity measures, and the relative performances of the maps in accurately describing the trauma population were evaluated. RESULTS: The double-coded injuries sustained by 109 patients were used to assess the maps. For data conversion from AIS98, both the enhanced map and the enhanced map with free text description resulted in higher levels of accuracy and agreement with directly coded AIS08 data than the currently available dictionary map. Paired comparisons demonstrated significant differences between direct coding and the dictionary maps, but not with either of the enhanced maps. CONCLUSIONS: The newly-developed AIS98 to AIS08 complementary map enabled transformation of the trauma population description given by AIS98 into an AIS08 estimate which was statistically indistinguishable from directly coded AIS08 data. It is recommended that the enhanced map should be adopted for dataset conversion, using free text descriptions if available

The extracellular matrix proteins laminin and fibronectin modify the AMPase activity of 5'-nucleotidase from chicken gizzard smooth muscle

AbstractLaminin and fibronectin, but not collagen, affect the AMPase activity of the purified transmembrane protein 5'-nucleotidase. Laminin stimulates whereas fibronectin inhibits the AMPase activity of this ectoenzyme. The AMPase-modulating effects by these components of the extracellular matrix require a preincubation period of several hours when detergent-solubilized 5'-nucleotidase is employed, they can, however, instantaneously be elicited with liposome-incorporated 5/-nucleotidase

Evaluation of contraceptive methods in women with congenital heart disease in Germany, Hungary and Japan

Aims For women with congenital heart defects (CHD), pregnancy may pose a health risk. Sexually active women with CHD without the desire for own children or for whom pregnancy would imply considerable health risks require adequate counselling regarding appropriate contraception. This study gathers data on the contraceptive behaviour of women with CHD from three different cultural regions. Methods and results 634 women with CHD from Germany, Hungary and Japan were surveyed regarding contraception and contraceptive methods (CM) used. The patients were divided into groups according to different criteria such as pregnancy associated cardiovascular risk or "safety" of the contraceptive methods used. 59% of the study participants had already gained experience with CM. The average age at the first time of use was 18.4 years; the German patients were significantly younger at the first time of using a CM than those from Hungary and Japan. Overall the condom was the method used the most (38%), followed by oral contraceptives (30%) and coitus interruptus (11%). The range of CM used in Japan was much smaller than that in Germany or Hungary. Unsafe contraceptives were currently, or had previously been used, by 29% of the surveyed patients (Germany: 25%, Hungary: 37%, Japan: 32%). Conclusion Most women with CHD use CM. There are differences between the participating countries. Adequate contraceptive counselling of women with CHD requires considering the individual characteristics of each patient, including potential contraindications. For choosing an appropriate CM, both the methods' "safety", as well as the maternal cardiovascular risk, are important. © 2015 Elsevier Ireland Ltd

Using Synchronic and Diachronic Relations for Summarizing Multiple Documents Describing Evolving Events

In this paper we present a fresh look at the problem of summarizing evolving events from multiple sources. After a discussion concerning the nature of evolving events we introduce a distinction between linearly and non-linearly evolving events. We present then a general methodology for the automatic creation of summaries from evolving events. At its heart lie the notions of Synchronic and Diachronic cross-document Relations (SDRs), whose aim is the identification of similarities and differences between sources, from a synchronical and diachronical perspective. SDRs do not connect documents or textual elements found therein, but structures one might call messages. Applying this methodology will yield a set of messages and relations, SDRs, connecting them, that is a graph which we call grid. We will show how such a grid can be considered as the starting point of a Natural Language Generation System. The methodology is evaluated in two case-studies, one for linearly evolving events (descriptions of football matches) and another one for non-linearly evolving events (terrorist incidents involving hostages). In both cases we evaluate the results produced by our computational systems.Comment: 45 pages, 6 figures. To appear in the Journal of Intelligent Information System

Articular cartilage mineralization in osteoarthritis of the hip

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to examine the frequency of articular cartilage calcification in patients with end-stage hip OA. Further, its impact on the clinical situation and the OA severity are analyzed.</p> <p>Methods</p> <p>Eighty patients with OA of the hip who consecutively underwent total hip replacement were prospectively evaluated, and 10 controls were included. The patients' X-rays were analyzed for the presence of articular cartilage mineralization. A Harris Hip Score (HHS) was preoperatively calculated for every patient.</p> <p>Slab specimens from the femoral head of bone and cartilage and an additional square centimeter of articular cartilage from the main chondral defect were obtained from each patient for analysis of mineralization by digital contact radiography (DCR). Histological grading was also performed. In a subset of 20 patients, minerals were characterized with an electron microscope (FE-SEM).</p> <p>Results</p> <p>Calcifications were seen in all OA cartilage and slab specimens using DCR, while preoperative X-rays revealed calcification in only 17.5%. None of the control cartilage specimens showed mineralization. There was a highly significant inverse correlation between articular cartilage calcification and preoperative HHS. Histological OA grade correlated positively with the amount of matrix calcification. FE-SEM analysis revealed basic calcium phosphate (BCP) as the predominant mineral; CPPD crystals were found in only two patients.</p> <p>Conclusions</p> <p>Articular cartilage calcification is a common event in osteoarthritis of the hip. The amount of calcification correlates with clinical symptoms and histological OA grade.</p