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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Einfluss eines Sphingosin-1-Phosphat Strukturanalogons auf den Ischämie-Reperfusionsschaden des Pankreas der Ratte

Prescher, Andrea 02 April 2014 (has links) (PDF)
Nach Ischämie und Reperfusion des Pankreas kommt es zu einer Mikrozirkulationsstörung sowie zu einer T-Zell-induzierten subakuten entzündlichen Reaktion mit daraus resultierender Zellzerstörung. Ziel dieser tierexperimentellen Arbeit war es, sowohl den Einfluss des S1PStrukturanalogons FTY720 auf zirkulierende T-Lymphozyten und deren Endothel- Interaktion in den postkapillären Venolen des Pankreas zu beobachten sowie die Mikrozirkulation und damit das Ausmaß des Ischämie-Reperfusionsschadens nach einer 60-minütigen Pankreasischämie durch die Gabe von FTY720 zu beurteilen. Hierfür erfolgte eine reversible Okklusion der zuführenden Gefäße des Pankreas an Ratten (48 Wistar-Ratten, 300 - 350 g KG) für 60 Minuten zur Induktion einer normothermen Pankreasischämie. Untersucht wurden folgende Gruppen: I Scheinoperation ohne Therapie, II Scheinoperation und Therapie, III Ischämie ohne Therapie, IV Ischämie und Therapie mit dem Sphingosin-1-Phosphat Strukturanalogon FTY720 (1 mg/kg KG i.v., Substitution 10 Minuten vor Reperfusionsbeginn). Mit Hilfe der invivo-Fluoreszenzmikroskopie wurden die Parameter der Mikrozirkulation (Zellzahl, Flussgeschwindigkeit, Kapillardurchmesser, Funktionelle Kapillardichte, T-Lymphozyten-Endothel-Interaktion und Leukozyten-Endothel- Interaktion) 10 Minuten nach Substitution der markierten CD4+-T-Lymphozyten beurteilt. Des Weiteren wurde der Blutparameter Lipase bestimmt. Die Studie erbrachte folgende Ergebnisse: 1. Die intravenöse Therapie mit FTY720 als Sphingosin 1-Phosphat-Rezeptor- Agonist 15 Minuten vor Reperfusion führte zu einer partiellen Verbesserung der Mikrozirkulation des Pankreas mit signifikant erhöhten Kapillardurchmesser und Funktioneller Kapillardichte. 2. Es zeichneten sich bei allen weiteren Parametern nur Tendenzen einer Verbesserung unter Substitution von FTY720 ab (Flussgeschwindigkeit, Lipase). 3. Eine Aussage zur T-Lymphozyten-Endothel-Interaktion konnte aufgrund der geringen Anzahl von „rollern“ und „stickern“ nicht gemacht werden. 4. Eine quantitative Auswertung der zirkulierenden Leukozyten war nicht möglich. Das vorliegende Bildmaterial war jedoch in allen Gruppen identisch, sodass hier kein Effekt von FTY720 auf zirkulierende Leukozyten nachweisbar war. 5. Zu einer signifikanten Zunahme der T-Lymphozyten-Zahl kam es in der Gruppe IV (Ischämie und Therapie mit FTY720). Die Ergebnisse dieser tierexperimentellen Untersuchung zeigen, dass die intraoperative Gabe des Immunmodulators FTY720 nur partiell eine Verbesserung der Mirkozirkulation und daraus resultierend eine Verminderung des Ischämie-Reperfusionsschadens bewirkt. Nach den Ergebnissen dieser Studie und dem aktuellen Stand der Literatur wäre somit für ein optimales Wirkmaximum die präoperative Gabe von FTY720 erforderlich. Die Studie zeigt ebenfalls, dass die Substitution der markierten CD4+-T-Lymphozyten zu einem früheren Zeitpunkt erfolgen muss, um eine Wirkung des FTY720 auf diese T-Zellen nachweisen zu können.
2

Clinical impact of duodenal pancreatic heterotopia – Is there a need for surgical treatment?

Betzler, Alexander, Mees, Soeren Torge, Pump, Josefine, Schölch, Sebastian, Zimmermann, Carolin, Aust, Daniela E., Weitz, Jürgen, Welsch, Thilo, Distler, Marius 27 July 2017 (has links) (PDF)
Background Pancreatic heterotopia (PH) is defined as ectopic pancreatic tissue outside the normal pancreas and its vasculature and duct system. Most frequently, PH is detected incidentally by histopathological examination. The aim of the present study was to analyze a large single-center series of duodenal PH with respect to the clinical presentation. Methods A prospective pancreatic database was retrospectively analyzed for cases of PH of the duodenum. All pancreatic and duodenal resections performed between January 2000 and October 2015 were included and screened for histopathologically proven duodenal PH. PH was classified according to Heinrich’s classification (Type I acini, ducts, and islet cells; Type II acini and ducts; Type III only ducts). Results A total of 1274 pancreatic and duodenal resections were performed within the study period, and 67 cases of PH (5.3%) were identified. The respective patients were predominantly male (72%) and either underwent pancreatoduodenectomy (n = 60); a limited pancreas resection with partial duodenal resection (n = 4); distal pancreatectomy with partial duodenal resection (n = 1); total pancreatectomy (n = 1); or enucleation (n = 1). Whereas 65 patients (83.5%) were asymptomatic, 11 patients (18.4%) presented with symptoms related to PH (most frequently with abdominal pain [72%] and duodenal obstruction [55%]). Of those, seven patients (63.6%) had chronic pancreatitis in the heterotopic pancreas. The risk of malignant transformation into adenocarcinoma was 2.9%. Conclusions PH is found in approximately 5% of pancreatic or duodenal resections and is generally asymptomatic. Chronic pancreatitis is not uncommon in heterotopic pancreatic tissue, and even there is a risk of malignant transformation. PH should be considered for the differential diagnosis of duodenal lesions and surgery should be considered, especially in symptomatic cases.
3

Clinical impact of duodenal pancreatic heterotopia – Is there a need for surgical treatment?

Betzler, Alexander, Mees, Soeren Torge, Pump, Josefine, Schölch, Sebastian, Zimmermann, Carolin, Aust, Daniela E., Weitz, Jürgen, Welsch, Thilo, Distler, Marius 27 July 2017 (has links)
Background Pancreatic heterotopia (PH) is defined as ectopic pancreatic tissue outside the normal pancreas and its vasculature and duct system. Most frequently, PH is detected incidentally by histopathological examination. The aim of the present study was to analyze a large single-center series of duodenal PH with respect to the clinical presentation. Methods A prospective pancreatic database was retrospectively analyzed for cases of PH of the duodenum. All pancreatic and duodenal resections performed between January 2000 and October 2015 were included and screened for histopathologically proven duodenal PH. PH was classified according to Heinrich’s classification (Type I acini, ducts, and islet cells; Type II acini and ducts; Type III only ducts). Results A total of 1274 pancreatic and duodenal resections were performed within the study period, and 67 cases of PH (5.3%) were identified. The respective patients were predominantly male (72%) and either underwent pancreatoduodenectomy (n = 60); a limited pancreas resection with partial duodenal resection (n = 4); distal pancreatectomy with partial duodenal resection (n = 1); total pancreatectomy (n = 1); or enucleation (n = 1). Whereas 65 patients (83.5%) were asymptomatic, 11 patients (18.4%) presented with symptoms related to PH (most frequently with abdominal pain [72%] and duodenal obstruction [55%]). Of those, seven patients (63.6%) had chronic pancreatitis in the heterotopic pancreas. The risk of malignant transformation into adenocarcinoma was 2.9%. Conclusions PH is found in approximately 5% of pancreatic or duodenal resections and is generally asymptomatic. Chronic pancreatitis is not uncommon in heterotopic pancreatic tissue, and even there is a risk of malignant transformation. PH should be considered for the differential diagnosis of duodenal lesions and surgery should be considered, especially in symptomatic cases.
4

Vývoj a funkce endokrinních buněk pankreatu / Development and function of endocrine cells of the pancreas

Hamplová, Adéla January 2019 (has links)
Diabetes mellitus affects nearly 300 million people in the world. The development of diabetes is caused by dysfunction or by reduction of insulin-producing β-cells that are part of the endocrine pancreas. Therefore, the most critical step for understanding the pathophysiology of diabetes and for restoring lost β cells is the identification of molecular cues that specify the cellular phenotype in the pancreas. This work is based on the hypothesis that the transcription factor NEUROD1 is a key factor for the development of the pancreas and for the maintenance of endocrine tissue function. Neurod1 conditional KO mutants (Neurod1CKO) were generated using the Cre-loxP system by crossing floxed Neurod1 mice with Isl1-Cre line. Immunohistochemical analyses of the pancreas at embryonic day 17.5 and postnatal day 0 showed that the deletion of Neurod1 negatively affected the development, organization of endocrine tissue, and total mass of pancreatic endocrine cells. To better understand molecular changes, quantitative PCR was used to analyse mRNA expression in the developing pancreas at the age of embryonic day 14.5 and postnatal day 1. Genes important for the development and function of the pancreas have been selected for the study of expression changes. These analyses showed changes in expression of genes...
5

Transkutane und intraabdominale Ultraschalluntersuchungen des Pankreas am stehenden Rind

Klein, Astrid 11 June 2012 (has links) (PDF)
This paper highlights two methods of examining the bovine pancreas by means of ultrasound, with a view to identifying advantages and disadvantages of the two techniques as well as testing and comparing their practicability. The goal is to evaluate the applicability of this intraoperative procedure to large animals - it is quite commonly used on humans - as well as present the resulting findings with regard to the ultrasonographic anatomy of the bovine pancreas. The sample consisted of 15 female beef cattle, none of which displayed evidence of any pancreatopathy based on their medical history, clinical examinations, and laboratory diagnostic testing. Transcutaneous and intraoperative sonographic examinations were performed on all 15 animals.
6

Funktionelle Charakterisierung der Transkriptionsfaktoren Nkx2.2 und Arx in der Entwicklung der endokrinen Zellen im murinen Pankreas / Role of Nkx2.2 and Arx in the development of the pancreatic endocrine cells

Kordowich, Simon 05 July 2011 (has links)
No description available.
7

Sledování genetických faktorů ovlivňujících riziko vzniku a průběh karcinomů kolorekta a pankreatu / Study of genetic factors modifying the risk of onset and progression of colorectal and pancreatic cancer

Mohelníková Duchoňová, Beatrice January 2012 (has links)
Introduction: The aim of this study was to evaluate the role of genetic and lifestyle factors in the risk of onset and progression of colorectal and pancreatic cancer. The first part deals with the etiological factors and the importance of polymorphisms in biotransformation enzymes and genetic alterations in the gene CHEK2 in the origin of these malignancies. In the second part, the ABC transporter genes were analyzed as potential prognostic and predictive markers of a treatment's outcome. Materials and methods: The polymorphisms and other genetic alterations were detected using real-time PCR, allelespecific PCR and PCR-RFLP methods in DNA which was extracted from the blood of patients. The frequency of polymorphisms was evaluated and their importance was assessed with regard to the available epidemiological data. Gene expressions were determined by qPCR in paired samples of tumor tissue and adjacent non-tumorous parenchyma. Results: A majority of the observed polymorphisms failed to show a relationship between their presence and the risk of any of these malignancies. CYP2A13 variant allele*7 coding inactive enzyme was found in 7 of 265 controls and in none of 235 pancreatic carcinoma patients. In contrast, GSTP1-codon 105 Val variant allele and GSTT1-null genotype were associated with an elevated...
8

Sledování genetických faktorů ovlivňujících riziko vzniku a průběh karcinomů kolorekta a pankreatu / Study of genetic factors modifying the risk of onset and progression of colorectal and pancreatic cancer

Mohelníková Duchoňová, Beatrice January 2012 (has links)
Introduction: The aim of this study was to evaluate the role of genetic and lifestyle factors in the risk of onset and progression of colorectal and pancreatic cancer. The first part deals with the etiological factors and the importance of polymorphisms in biotransformation enzymes and genetic alterations in the gene CHEK2 in the origin of these malignancies. In the second part, the ABC transporter genes were analyzed as potential prognostic and predictive markers of a treatment's outcome. Materials and methods: The polymorphisms and other genetic alterations were detected using real-time PCR, allelespecific PCR and PCR-RFLP methods in DNA which was extracted from the blood of patients. The frequency of polymorphisms was evaluated and their importance was assessed with regard to the available epidemiological data. Gene expressions were determined by qPCR in paired samples of tumor tissue and adjacent non-tumorous parenchyma. Results: A majority of the observed polymorphisms failed to show a relationship between their presence and the risk of any of these malignancies. CYP2A13 variant allele*7 coding inactive enzyme was found in 7 of 265 controls and in none of 235 pancreatic carcinoma patients. In contrast, GSTP1-codon 105 Val variant allele and GSTT1-null genotype were associated with an elevated...
9

Einfluss eines Sphingosin-1-Phosphat Strukturanalogons auf den Ischämie-Reperfusionsschaden des Pankreas der Ratte

Prescher, Andrea 28 January 2014 (has links)
Nach Ischämie und Reperfusion des Pankreas kommt es zu einer Mikrozirkulationsstörung sowie zu einer T-Zell-induzierten subakuten entzündlichen Reaktion mit daraus resultierender Zellzerstörung. Ziel dieser tierexperimentellen Arbeit war es, sowohl den Einfluss des S1PStrukturanalogons FTY720 auf zirkulierende T-Lymphozyten und deren Endothel- Interaktion in den postkapillären Venolen des Pankreas zu beobachten sowie die Mikrozirkulation und damit das Ausmaß des Ischämie-Reperfusionsschadens nach einer 60-minütigen Pankreasischämie durch die Gabe von FTY720 zu beurteilen. Hierfür erfolgte eine reversible Okklusion der zuführenden Gefäße des Pankreas an Ratten (48 Wistar-Ratten, 300 - 350 g KG) für 60 Minuten zur Induktion einer normothermen Pankreasischämie. Untersucht wurden folgende Gruppen: I Scheinoperation ohne Therapie, II Scheinoperation und Therapie, III Ischämie ohne Therapie, IV Ischämie und Therapie mit dem Sphingosin-1-Phosphat Strukturanalogon FTY720 (1 mg/kg KG i.v., Substitution 10 Minuten vor Reperfusionsbeginn). Mit Hilfe der invivo-Fluoreszenzmikroskopie wurden die Parameter der Mikrozirkulation (Zellzahl, Flussgeschwindigkeit, Kapillardurchmesser, Funktionelle Kapillardichte, T-Lymphozyten-Endothel-Interaktion und Leukozyten-Endothel- Interaktion) 10 Minuten nach Substitution der markierten CD4+-T-Lymphozyten beurteilt. Des Weiteren wurde der Blutparameter Lipase bestimmt. Die Studie erbrachte folgende Ergebnisse: 1. Die intravenöse Therapie mit FTY720 als Sphingosin 1-Phosphat-Rezeptor- Agonist 15 Minuten vor Reperfusion führte zu einer partiellen Verbesserung der Mikrozirkulation des Pankreas mit signifikant erhöhten Kapillardurchmesser und Funktioneller Kapillardichte. 2. Es zeichneten sich bei allen weiteren Parametern nur Tendenzen einer Verbesserung unter Substitution von FTY720 ab (Flussgeschwindigkeit, Lipase). 3. Eine Aussage zur T-Lymphozyten-Endothel-Interaktion konnte aufgrund der geringen Anzahl von „rollern“ und „stickern“ nicht gemacht werden. 4. Eine quantitative Auswertung der zirkulierenden Leukozyten war nicht möglich. Das vorliegende Bildmaterial war jedoch in allen Gruppen identisch, sodass hier kein Effekt von FTY720 auf zirkulierende Leukozyten nachweisbar war. 5. Zu einer signifikanten Zunahme der T-Lymphozyten-Zahl kam es in der Gruppe IV (Ischämie und Therapie mit FTY720). Die Ergebnisse dieser tierexperimentellen Untersuchung zeigen, dass die intraoperative Gabe des Immunmodulators FTY720 nur partiell eine Verbesserung der Mirkozirkulation und daraus resultierend eine Verminderung des Ischämie-Reperfusionsschadens bewirkt. Nach den Ergebnissen dieser Studie und dem aktuellen Stand der Literatur wäre somit für ein optimales Wirkmaximum die präoperative Gabe von FTY720 erforderlich. Die Studie zeigt ebenfalls, dass die Substitution der markierten CD4+-T-Lymphozyten zu einem früheren Zeitpunkt erfolgen muss, um eine Wirkung des FTY720 auf diese T-Zellen nachweisen zu können.
10

Mouse Pancreas Tissue Slice Culture Facilitates Long-Term Studies of Exocrine and Endocrine Cell Physiology in situ

Speier, Stephan, Marciniak, Anja, Selck, Claudia, Friedrich, Betty 02 December 2015 (has links) (PDF)
Studies on pancreatic cell physiology rely on the investigation of exocrine and endocrine cells in vitro. Particularly, in the case of the exocrine tissue these studies have suffered from a reduced functional viability of acinar cells in culture. As a result not only investigations on dispersed acinar cells and isolated acini were limited in their potential, but also prolonged studies on pancreatic exocrine and endocrine cells in an intact pancreatic tissue environment were unfeasible. To overcome these limitations, we aimed to establish a pancreas tissue slice culture platform to allow long-term studies on exocrine and endocrine cells in the intact pancreatic environment. Mouse pancreas tissue slice morphology was assessed to determine optimal long-term culture settings for intact pancreatic tissue. Utilizing optimized culture conditions, cell specificity and function of exocrine acinar cells and endocrine beta cells were characterized over a culture period of 7 days. We found pancreas tissue slices cultured under optimized conditions to have intact tissue specific morphology for the entire culture period. Amylase positive intact acini were present at all time points of culture and acinar cells displayed a typical strong cell polarity. Amylase release from pancreas tissue slices decreased during culture, but maintained the characteristic bell-shaped dose-response curve to increasing caerulein concentrations and a ca. 4-fold maximal over basal release. Additionally, endocrine beta cell viability and function was well preserved until the end of the observation period. Our results show that the tissue slice culture platform provides unprecedented maintenance of pancreatic tissue specific morphology and function over a culture period for at least 4 days and in part even up to 1 week. This analytical advancement now allows mid -to long-term studies on the cell biology of pancreatic disorder pathogenesis and therapy in an intact surrounding in situ.

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