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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.
241

Delineating the function, efficacy, and mechanism of a novel preclinical agent for the treatment of pancreatic ductal adenocarcinoma

Eberle-Singh, Jaime January 2018 (has links)
In 2018, it is estimated that 55,440 Americans will be diagnosed with pancreatic cancer and this figure is expected to continue to rise with increased life expectancy. Despite some measurable progress over the past few decades, pancreatic cancer remains one of the most lethal malignancies with five-year survival rate of 8.7%. Novel therapies, and their timely translation to the clinic, are urgently needed. As part of an effort to identify and characterize novel therapeutic strategies for pancreatic ductal adenocarcinoma, we began a study of the role of Bmi1 in tumor maintenance and progression. While Bednar and colleagues showed that Bmi1 is critical for the development of pancreatic cancer, and that its pancreas-specific deletion impairs PanIN formation, we were interested in assessing its function in established tumors. During the course of this work, we acquired a novel compound, PTC596, developed by PTC Therapeutics as a post-translational inhibitor of BMI1. Treatment with PTC596 leads to hyperphosphorylated BMI1, and this modification is associated a loss of protein activity. We planned to study this compound, in vitro and in vivo, as a complement to genetic perturbations of Bmi1. Initial characterizations of the effects of PTC596 on human and murine-derived pancreatic cancer cell lines revealed a potent anti-proliferative effect, accompanied by BMI1 hyperphosphorylation, and followed by polyploidy and cell death after prolonged treatment. Further analysis showed a clear G2/M arrest and elevated levels of phospho-histone H3. Bmi1 is known to play a role the cell cycle, but its inhibition in pancreatic cancer cell lines has been shown to induce G1 arrest. We decided to further explore the mechanism of PTC596’s antiproliferative effects by carrying out RNA sequencing on Aspc1 cells treated with PTC596. We found that 8 of the ten most down-regulated genes were members of the tubulin family and began to study this compound’s effect on microtubules. Compelling results from a cell-free tubulin polymerization assay support inhibition of tubulin polymerization as the mechanism of action for PTC596. These data are further supported by evidence that PTC596 increases the fraction of free-tubulin in treated cells, as well as dramatically alters the cell’s microtubule network. Given our laboratory’s interest in identifying novel therapies for pancreatic cancer, and the fact that PTC596 has already begun clinical trials, we continued to characterize this compound in vivo. We found PTC596 to have properties favorable for in vivo administration. PTC596 is orally available, has a plasma half-life of approximately 22 hours following oral administration, and accumulates in tumor tissue where it has an expected pharmacodynamic effect. Furthermore, it is well tolerated in vivo in combination with gemcitabine. We carried out a four-arm intervention study in tumor-bearing KPC mice, examining PTC596 alone and in combination with gemcitabine. We found that PTC596 synergizes with gemcitabine to significantly reduce tumor growth rates and provide a 3-fold extension of survival as compared to vehicle. These findings are, to our knowledge, the first evidence of in vivo synergy between a microtubule-destabilizing agent and gemcitabine for the treatment of pancreatic cancer. Importantly, this study identifies an alternative mechanism for PTC596 and implicates its efficacy in a novel treatment regimen for pancreatic ductal adenocarcinoma.
242

Avaliação do parênquima pancreático no Diabetes Mellitus através de métodos quantitativos de ressonância magnética / Evaluation of the pancreatic parenchyma in Diabetes Mellitus through quantitative Magnetic Resonance Imaging (MRI) techniques

Uyeno, Fábio Akira 29 May 2015 (has links)
Objetivos: Comparar quantitativamente por técnicas de ressonância magnética (RM), a fração de gordura pancreática em indivíduos sadios, obesos e diabéticos (tipos 1 e 2). Secundariamente, buscou-se identificar diferença das medidas do ADC (difusão) no parênquima pancreático. Materiais e Métodos: Estudo retrospectivo com avaliação por dois radiologistas de imagens de RM abdominal de 89 indivíduos (56 controles; 33 diabéticos). Utilizadas três sequências: T1-GRE em fase e fora de fase; difusão (mapa ADC). Calculados e comparados frações de gordura e valores médios do ADC pancreáticos nos grupos. Resultados: Observaram-se diferenças significativas da fração de gordura pancreática entre diabéticos tipo 2 (DM2) e sadios e diabéticos tipo 1 (DM1), com valores de p de 0,01 e 0,02 para homens e 0,02 e 0,01 para mulheres, com confiabilidade interobservador ótima (coeficiente de correlação intraclasse > 0,8). Em obesos não diabéticos, observaram-se frações de gordura pancreática semelhantes às dos diabéticos tipo 2. Observou-se também diferença significativa nos valores de ADC entre DM2 e sadios e DM1 (p: 0,02 e 0,03 no sexo masculino; p: 0,002 e 0,001 no sexo feminino), menores nos DM2. Discussão: Observaram-se frações de gordura pancreáticas significativamente maiores em DM2, comparativamente a indivíduos sadios e DM1, achado que fomenta a hipótese da infiltração gordurosa do órgão como um fator causal associado para a falência de células beta pancreáticas. / Objectives: To compare, through quantitative MRI techniques, the pancreatic fat fraction in healthy, obese and diabetic (type 1 and 2) individuals. Secondarily, weve tried to identify differences in ADC (diffusion) values in the pancreatic parenchyma. Materials and Methods: A retrospective study, with review, by two radiologists, of abdominal MR images of 89 subjects (56 controls; 33 diabetics). Three sequences have been used: T1-GRE in-phase and out-of-phase; diffusion (ADC map). Fat fractions and average values of the ADC in pancreatic parenchyma have been calculated and compared. Results: We observed significant differences between pancreatic fat fractions of diabetics type 2 (DM2) and healthy and diabetic type 1 (DM1) individuals, with p values of 0.01 and 0.02 for men and 0.02 and 0.01 for women, with good interobserver reliability (intraclass correlation coefficients > 0.8). Obese nondiabetic sujects showed high pancreatic fat fraction similar to DM2. There was also a significant difference in ADC values between DM2 and DM1 and healthy individuals (p: 0.02 and 0.03 in males; p: 0.002 and 0.001 in females), lower in DM2. Discussion: We observed significantly higher pancreatic fat fractions in DM2, when compared to healthy and DM1 individuals. This finding favors the hypothesis of fatty infiltration of the organ as an associated causal factor to the pancreatic beta cells failure.
243

Dimensões, conteúdo de gordura e perfusão do pâncreas em pacientes com diabetes : avaliação por métodos de imagem

Garcia, Tiago Severo January 2016 (has links)
A maioria dos estudos com ultrassonografia (US), tomografia computadorizada (TC) e ressonância magnética (RM) mostra que as dimensões do pâncreas são reduzidas em pacientes com diabetes, quando comparados com grupo controle. Dados sobre a perfusão pancreática em pacientes com diabetes são escassos na literatura. Essa tese tem por objetivo avaliar características do pâncreas nos exames de imagem que possam trazer uma melhor compreensão da patogênese e da fisiopatologia do diabetes. Primeiramente, realizamos uma revisão sistemática com metanálise de estudos que utilizaram métodos de imagem (US, TC ou RM) para a medida das dimensões – diâmetro, área ou volume - e do conteúdo de gordura do pâncreas em pacientes com diabetes tipo 1 (DM1) ou tipo 2 (DM2). Demonstramos que as dimensões pancreáticas são menores nos pacientes com DM1 ou DM2 em comparação com indivíduos sem diabetes. Além disso, o conteúdo de gordura do pâncreas é maior em pacientes com DM2. Com o intuito de investigar uma possível causa para a redução do volume do pâncreas em pacientes com diabetes, buscamos estudar a vascularização pancreática por meio de TC perfusional. Inicialmente, fizemos um estudo para avaliar a variabilidade intra e interobservador para a medida dos parâmetros de perfusão pancreática por TC (fluxo sanguíneo, volume sanguíneo, tempo de trânsito médio, tempo para o pico de realce), demonstrando que existe uma boa concordância nessas medidas, mesmo entre radiologistas com diferentes níveis de experiência. Em sequência, realizamos um estudo comparando esses parâmetros de perfusão pancreática por TC entre pacientes com DM2 e indivíduos sem diabetes. Mostramos que o volume sanguíneo que perfunde o pâncreas e o seu tempo de trânsito médio pelo órgão são menores em pacientes com DM2 em comparação com indivíduos não diabéticos.
244

Gastroduodenopancreatectomia: análise da morbidade e mortalidade / Gastroduodenopancreatectomy: analysis of morbidity and mortality

PACHECO, Jairo Sousa 10 September 2012 (has links)
Submitted by Daniella Santos (daniella.santos@ufma.br) on 2017-11-16T22:21:31Z No. of bitstreams: 1 JAIROPACHECO.pdf: 369663 bytes, checksum: 88040c6ca9dd34246e1a5b2567d1bc88 (MD5) / Made available in DSpace on 2017-11-16T22:21:31Z (GMT). No. of bitstreams: 1 JAIROPACHECO.pdf: 369663 bytes, checksum: 88040c6ca9dd34246e1a5b2567d1bc88 (MD5) Previous issue date: 2012-09-10 / Objective: To determine the major complications in patients undergoing gastroduodenopancreatectomy for pancreatic cancer and periampullary region, possible determinant factors and associated mortality. Methods: Retrospective study including patients diagnosed with pancreatic cancer and periampullary region undergone GDP from January 1987 to December 2007. Epidemiological and clinical data, laboratory and disease-related data and the procedure were reviewed. Results: 105 patients were included. Males represented 52%. Signs and/or symptoms more frequent were pain and jaundice. Jaundice was observed in 78.89%. Most didn´t have diabetes, and the use of alcohol and smoke was less frequent. Most were submitted to classical resection with median operative time of 440 minutes. Duct-to-mucosa pancreatic reconstruction was carried out in 69 patients. Complications were observed in 54 patients (51.4%). The mortality rate was 7.6% (eight patients). Pancreatic fistula was observed in 21 cases (20%), with 9 cases (8.5%) grade A, 2 (1.9%) grade B, and 10 (9.5%) grade C. Other complications observed were biliary fistula (5.7%), operative wound infection (5.7%), intraabdominal abscess/collection (5.7%) and hemoperitoneum (2.8%). Clinical complications observed were pneumonia (3.8%) and urinary tract infection (1.9%). High CA 19-9 tumor marker and duct-to-mucosa pancreatic enteric reconstruction technique presented a statistically significant result. Conclusion: Pancreatic fistula remains the most important complication associated with higher mortality. The surgical technique used and CA 19-9 were prognostic factors. In this study, the pancreatic reconstruction technique using ductto-mucosa anastomosis type presented less failure. / Objetivo: Determinar as principais complicações em pacientes submetidos a gastroduodenopancreatectomia por câncer de pâncreas e região periampolar, possíveis fatores determinantes e mortalidade associada. Métodos: Estudo retrospectivo incluindo pacientes com diagnóstico de câncer de pâncreas e região periampolar submetidos a gastroduodenopancreatectomia no período de janeiro de 1987 a dezembro de 2007. Dados clínicos e epidemiológicos, laboratoriais e dados relacionados a doença e ao procedimento foram revistos. Resultados: Foram incluídos 105 pacientes. Sexo masculino correspondeu a 52%. Sinais e/ou sintomas mais freqüentes foram dor e icterícia. Icterícia foi observada em 78,89%. A maioria não apresentava diabetes, e o uso de álcool e fumo foi menos freqüente. A maioria foi submetida a ressecção clássica com mediana do tempo operatório de 440 minutos. A reconstrução pancreática ducto-mucosa foi realizada em 69 pacientes. Complicações foram observadas em 54 pacientes (51,4%). A mortalidade foi de 7,6% (oito pacientes). Fístula pancreática foi observada em 21 casos (20%), sendo 9 casos (8,5%) grau A, 2 (1,9%) grau B e 10 (9,5%) grau C. Outras complicações observadas foram fístula biliar (5,7%), infecção de ferida operatória (5,7%), coleção/abscesso intra-abdominal (5,7%) e hemoperitônio (2,8%). Complicações clínicas observadas foram pneumonia (3,8%) e infecção do trato urinário (1,9%). Marcador tumoral CA 19-9 elevado e a técnica de reconstrução pancreatoentérica ducto mucosa apresentaram resultado estatisticamente significativo. Conclusão: Fístula pancreática permanece a complicação mais importante, associada a maior mortalidade. A técnica cirúrgica empregada e CA 19-9 foram fator prognóstico. Nesse estudo, a técnica de reconstrução pancreática utilizando a anastomose tipoducto-mucosa apresentou menor falha.
245

Studies on some immune properties of the pancreatic progenitor cells derived from human fetal pancreas.

January 2010 (has links)
Ma, Man Ting. / "July 2010." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 186-207). / Abstracts in English and Chinese. / Abstract --- p.I / List of Publications --- p.VI / Acknowledgements --- p.VIII / Table of Contents --- p.X / List of Figures --- p.XV / List of Tables --- p.XVIII / List of Abbreviations --- p.XIX / Chapter CHAPTER1 --- INTRODUCTION / Chapter 1.1 --- The Pancreas --- p.2 / Chapter 1.1.1 --- Structure of pancreas --- p.2 / Chapter 1.1.2 --- Structure and function of exocrine pancreas --- p.6 / Chapter 1.1.3 --- Structure and function of endocrine pancreas --- p.9 / Chapter 1.1.3.1 --- Pancreatic islet and islet cells --- p.9 / Chapter 1.1.3.2 --- Glucose-stimulated insulin secretion from islets --- p.12 / Chapter 1.2 --- Type 1 Diabetes Mellitus (T1DM) --- p.14 / Chapter 1.2.1 --- Pathophysiology of Diabetes Mellitus --- p.14 / Chapter 1.2.2 --- Autoimmunity in T1DM --- p.17 / Chapter 1.2.3 --- Management ofTlDM --- p.20 / Chapter 1.2.3.1 --- Insulin replacement --- p.20 / Chapter 1.2.3.2 --- Pancreas and islet transplantation --- p.21 / Chapter 1.2.3.3 --- Stem-cell-based transplantation --- p.22 / Chapter 1.3 --- The Adaptive Immune System --- p.26 / Chapter 1.3.1 --- T-lymphocytes --- p.26 / Chapter 1.3.2 --- B-lymphocytes --- p.29 / Chapter 1.3.3 --- Major histocompatibility complex (MHC) --- p.30 / Chapter 1.3.3.1 --- Classification of MHC molecules --- p.30 / Chapter 1.3.3.2 --- Structure of MHC class I and II molecules --- p.32 / Chapter 1.3.3.3 --- Function and regulation of MHC molecules --- p.34 / Chapter 1.3.4 --- HLA-G and its immuno-modulatory properties --- p.36 / Chapter 1.4 --- Transplantation Rejection --- p.40 / Chapter 1.4.1 --- Mechanisms involved in transplantation rejection --- p.40 / Chapter 1.4.2 --- Immunobiology of rejection --- p.41 / Chapter 1.4.2.1 --- Direct allorecognition pathway --- p.42 / Chapter 1.4.2.2 --- Indirect allorecognition pathway --- p.43 / Chapter 1.4.2.3 --- Semi-direct allorecognition pathway --- p.43 / Chapter 1.4.3 --- Xenotransplantation --- p.46 / Chapter 1.5 --- Cytokines and Immunity --- p.48 / Chapter 1.5.1 --- Interferons --- p.48 / Chapter 1.5.1.1 --- Interferon-γ and its immune regulation --- p.49 / Chapter 1.5.1.2 --- Effect and kinetics of interferon-γ on MHC molecules expression --- p.53 / Chapter 1.5.1.3 --- Regulation of interferon-γ production --- p.56 / Chapter 1.5.2 --- Interlukins --- p.58 / Chapter 1.5.2.1 --- IL-10 and its immune regulation --- p.58 / Chapter 1.5.2.2 --- IL-10 and HLA-G --- p.59 / Chapter 1.6 --- Stem Cells and their Immunogenicity --- p.62 / Chapter 1.6.1 --- Embroynic stem cells --- p.62 / Chapter 1.6.2 --- Mesenchymal stem cells --- p.64 / Chapter 1.6.3 --- Neural stem cells --- p.68 / Chapter 1.6.4 --- Fetal stem cells --- p.69 / Chapter 1.6.5 --- Potential immuno-study in human fetal pancreatic stem cells --- p.70 / Chapter 1.7 --- Aims and Objectives of study --- p.72 / Chapter CHAPTER2 --- MATERIALS AND METHODS / Chapter 2.1 --- Isolation of Pancreatic Progenitors (PPCs) from Human Fetal Pancreas and Induction of Islet-like Cell Cluster (ICCs) Differentiation --- p.75 / Chapter 2.1.1 --- Tissue procurement --- p.75 / Chapter 2.1.2 --- Tissue processing and PPCs culture --- p.75 / Chapter 2.1.3 --- In vitro differentiation of PPCs into ICCs --- p.78 / Chapter 2.1.4 --- Interferon-γ and IL-10 treatment --- p.80 / Chapter 2.2 --- Cell culture of human placental Choriocarcinoma JEG-3 Cell Line --- p.81 / Chapter 2.3 --- RNA Expression Detection --- p.82 / Chapter 2.3.1 --- RNA isolation --- p.82 / Chapter 2.3.2 --- Reverse transcriptase (RT) --- p.83 / Chapter 2.3.3 --- Design of primers for Polymerase Chain Reaction (PCR) and Real-time PCR --- p.84 / Chapter 2.3.4 --- PCR --- p.86 / Chapter 2.3.5 --- Real-time PCR analysis --- p.88 / Chapter 2.3.6 --- Calculation using the comparative CT method --- p.90 / Chapter 2.4 --- Flow Cytometry --- p.91 / Chapter 2.5 --- Western Blotting Analysis --- p.93 / Chapter 2.5.1 --- Protein extraction and quantification --- p.93 / Chapter 2.5.2 --- Western blotting --- p.93 / Chapter 2.6 --- Mixed Lymphocyte Reaction (MLR) --- p.95 / Chapter 2.6.1 --- Isolation of peripheral blood mononuclear cells (PBMCs) --- p.95 / Chapter 2.6.2 --- PPC-PBMCs MLR --- p.98 / Chapter 2.6.3 --- ICC-PBMCs MLR --- p.98 / Chapter 2.6.4 --- Proliferation assay --- p.99 / Chapter 2.7 --- ICC Transplantation --- p.101 / Chapter 2.7.1 --- Streptozotocin-induced diabetic animals for transplantation --- p.101 / Chapter 2.7.2 --- Procedures of ICCs transplantation --- p.102 / Chapter 2.8 --- Histological Analysis of ICC Graft --- p.105 / Chapter 2.8.1 --- H&E staining --- p.105 / Chapter 2.8.2 --- DAB staining --- p.106 / Chapter 2.8.3 --- Immunofluorescence staining --- p.107 / Chapter 2.9 --- Enzyme-linked Immunosorbent Assay (ELISA) --- p.109 / Chapter 2.10 --- Statistical Data Analysis --- p.110 / Chapter CHAPTER3 --- RESULTS / Chapter 3.1 --- Immuno-characterization of PPCs and ICCs --- p.112 / Chapter 3.2 --- Effect of cytokines on immune-properties of PPCs and ICCs --- p.115 / Chapter 3.2.1 --- Effect of lFN-γ on MHC-I expression in PPCs --- p.115 / Chapter 3.2.2 --- Effect of lFN-γ and IL-10 on HLA-G expression in PPCs and ICCs --- p.119 / Chapter 3.2.3 --- Effect of IFN-γ on B7H4 expression in PPCs --- p.123 / Chapter 3.3 --- Comparison of immune-properties of PPCs and ICCs from 1st and 2nd trimester --- p.125 / Chapter 3.3.1 --- Differential expression of MHC molecules in PPCs --- p.125 / Chapter 3.3.2 --- Different immune-related gene expression in PPCs and ICCs --- p.128 / Chapter 3.3.3 --- Comparison of IFN-γ activated MHC molecules expression in PPCs/ICCs --- p.134 / Chapter 3.3.4 --- Comparison of other IFN-γ activated genes expression in PPCs --- p.139 / Chapter 3.4 --- Mixed lymphocyte reaction of PPCs from 1st and 2nd trimester --- p.143 / Chapter 3.4.1 --- Effect of PPCs on proliferation of PBMC --- p.143 / Chapter 3.4.2 --- Effect of ICCs on proliferation of PBMC --- p.145 / Chapter 3.4.3 --- Effect of PPCs on cytokine production in PBMC --- p.149 / Chapter 3.5 --- Xenotransplantation of ICCs into diabetic mouse model --- p.152 / Chapter 3.5.1 --- Blood glucose level of diabetic mice after transplantation --- p.152 / Chapter 3.5.2 --- Histological evaluation of transplanted ICCs grafts --- p.154 / Chapter 3.5.3 --- Infiltration of CD45 into transplanted grafts of 1st and 2nd trimester --- p.158 / Chapter CHAPTER4 --- DISCUSSION / Chapter 4.1 --- Expression of selected immuno-regulated genes in PPCs and ICCs --- p.163 / Chapter 4.2 --- Effect of IFN-g and IL-10 on expression of immuno-regulated genes in PPCs and ICCs --- p.166 / Chapter 4.3 --- In vitro studies on immunogenicity of PPCs and ICCs from first and second trimester --- p.171 / Chapter 4.3.1 --- Immune-related genes expression --- p.171 / Chapter 4.3.2 --- IFN-γ activated gene expression --- p.173 / Chapter 4.3.3 --- Mixed lymphocyte reaction --- p.175 / Chapter 4.3.4 --- Cytokine production of PBMC in MLR --- p.179 / Chapter 4.4 --- In vivo Xenotransplantation of ICCs into diabetic mouse model --- p.181 / Chapter 4.5 --- Conclusion --- p.187 / Chapter 4.6 --- Further studies --- p.188 / Chapter CHAPTER5 --- BIBLIOGRAPHY / Bibliography by Alphabetical Order --- p.189
246

Pharmacological ascorbate enhances oxygen consumption and epigenetic reprogramming in pancreatic cancer

Gibson, Adrienne Rae 01 August 2018 (has links)
Pharmacological ascorbate treatment (P-AscH-, high-dose, intravenous vitamin C) results in a short-term increased flux of H2O2 that is preferentially cytotoxic to cancer cells vs. normal cells. We hypothesized that there may be a sustained effect (> 24 h) of P-AscH- that may contribute to cytotoxicity. P-AscH- significantly increased sustained oxygen consumption (OCR), DCFH-DA oxidation, and extracellular acidification (ECAR) in tumor lines with no change in non-tumorigenic cells. One possible source of this sustained ROS and OCR, the NADPH oxidase family of enzymes Dual Oxidase 1 and 2 (DUOX), which are epigenetically silenced by methylation in vitro and in vivo in PDAC, are up-regulated with P-AscH- treatment. Catalase pretreatment reversed the P-AscH--induced increases in DUOX, while DUOX inhibition partially rescues P-AscH- toxicity. Additionally, nutritional ascorbate is unable to mediate the increase in DUOX expression. Together these results suggest that P-AscH--induced toxicity may be enhanced by late metabolic and epigenetic shifts in tumor cells resulting in a feed-forward mechanism of H2O2 generation and induction of metabolic stress via enhanced DUOX expression and OCR. These data highlight a novel epigenetic mechanism of action for P-AscH-.
247

Intraperitoneal 5-Fluorouracil treatment of cancer - clinical and experimental studies

Öman, Mikael January 2004 (has links)
<p>Background:Pancreas cancer is a most aggressive malignancy. More than 80% of patients diagnosed with pancreas cancer, exhibit such advanced disease, that curative surgery is impossible. Systemic chemotherapy prolongs survival to 5-9 months. High concentrations of chemotherapeutic agents in the abdominal cavity and in the lymphatics draining the area is achieved by intraperitoneal administration. Vasopressin decreases splanchnic blood flow, reducing the intraperitoneal uptake of drugs, thus raising the local and lymphatic dose intensity.</p><p>Aim: The aim of the study was to investigate the feasibility and tumour response of intraperitoneal 5-Fluorouracil (5-FU) treatment in non-resectable pancreas cancer, using vasopressin to improve the pharmacokinetic profile. Further, to study the effect of vasopressin on peritoneal blood flow, altered by intraperitoneal 5-FU or the presence of peritoneal carcinomatosis.</p><p>Methods: In the animal experiments, the 133Xe-clearance technique and as a comparison Laser doppler flow, were used to identify changes of peritoneal blood flow caused by vasopressin in unmanipulated animals and in animals with peritoneal carcinomatosis or animals given intraperitoneal 5-FU. In the clinical studies, 68 (39 women/29 men) patients, with a non-resectable ductal pancreas cancer and a Karnovsky Index ≥70 were included. Patients were treated with 750-1500 mg/m2 5-FU intraperitoneally through a Port-a-cath and Leucovorin 100 mg/m2 intravenously on two consecutive days every 21 days until progression. Seventeen patients, receiving 750 mg/m2 5-FU, were given concomitant vasopressin 0.1 IU/min during 180 minutes, alternatively day 1 or 2.</p><p>Results: In the animal experiments, vasopressin 0.07 IU/kg/min significantly reduced the 133Xe-clearance. Intraperitoneal 5-FU decreased the basal peritoneal blood flow and abrogated the vasopressin effect for 1-2 days. The presence of peritoneal carcinomatosis did not influence the basal peritoneal blood flow, nor the reduction of peritoneal blood flow caused by vasopressin. In the clinical studies, the treatment with intraperitoneal 5-FU was well tolerated, with no WHO Grade 3 or 4 toxicity with doses up to 1250 mg/m2. Thirty patients achieved at least stable disease at three months. The median survival time was 8.0 (range 0.8-54.1) months. There was a significant reduction of 5-FU Cmax on day 2, but no significant reduction of AUC, when vasopressin was given.</p><p>Conclusion: Peritoneal blood flow changes caused by vasopressin can be estimated with the 133Xe-clearance technique. Intraperitoneal 5-FU but not peritoneal carcinomatosis decreases the vasopressin induced 133Xe-clearance reduction, 1-2 days after administration. In patients with non-resectable pancreas cancer, intraperitoneal 5-FU up to 1250 mg/m2 for two days every third week can be given without WHO grade 3 and 4 toxicity. The treatment is well tolerated with few and minor side effects. Tumour responses were observed. Addition of vasopressin does not significantly enhance the pharmacokinetics of intraperitoneal 5-Flurorouracil, but adds toxicity.</p>
248

Blood Flow Regulation and Inflammatory Response in Experimental Models of Diabetes

Pettersson, Ulrika January 2012 (has links)
Type 2 diabetes is caused by defect pancreatic islet β-cells together with peripheral insulin resistance. The disease is often accompanied by obesity with associated low-grade visceral adipose tissue inflammation, which contributes to insulin resistance. As a consequence of, and a possible compensation for the increased insulin demand, blood flow to the pancreatic islets is increased in animal models of diabetes. This increased blood perfusion might with time affect the vascular network as well as β-cells within the islets. This thesis investigates the role of changes of blood perfusion in pancreatic islets and adipose tissues, as well as the recruitment to and composition of leukocyte subpopulations in insulin-sensitive tissues in experimental models of diabetes. Blood flow measurements in islets and adipose tissues of rats and mice were performed using the microsphere technique, while leukocyte recruitment was studied in the mouse cremaster muscle using intravital microscopy. Increased islet blood flow was observed in the GK rat model of type 2 diabetes, which was decreased by acute as well as continuous 2-week inhibition of β3-adrenoceptors without affecting plasma insulin concentrations. Increased inflammatory leukocyte recruitment was observed in both alloxan-induced and high-fat diet-induced diabetes. However, an impaired bacterial clearance was observed in diabetic mice, which was due to impaired phagocytosis. A gender difference was detected in mice fed a high-fat diet, since obese female mice did not show increased levels of pro-inflammatory circulatory markers or inflammatory leukocytes in the adipose tissue. The main effector cell in the adipose tissue inflammation in high-fat-fed male mice seemed to be the pro-inflammatory macrophage. The Treg population in adipose tissue was increased in female mice, but remained unchanged in male mice on high-fat diet. In conclusion, increased islet blood flow in type 2 diabetes could be reversed by β3-adrenoceptor inhibition, which may maintain islet function. The diabetes-associated hyperglycemia activated leukocytes but impaired their phagocytic ability. High-fat-fed female mice showed less peripheral inflammation due to a smaller number of recruited inflammatory macrophages and a high-fat diet-induced Treg population in intra-abdominal adipose tissues.
249

Intraperitoneal 5-Fluorouracil treatment of cancer - clinical and experimental studies

Öman, Mikael January 2004 (has links)
Background:Pancreas cancer is a most aggressive malignancy. More than 80% of patients diagnosed with pancreas cancer, exhibit such advanced disease, that curative surgery is impossible. Systemic chemotherapy prolongs survival to 5-9 months. High concentrations of chemotherapeutic agents in the abdominal cavity and in the lymphatics draining the area is achieved by intraperitoneal administration. Vasopressin decreases splanchnic blood flow, reducing the intraperitoneal uptake of drugs, thus raising the local and lymphatic dose intensity. Aim: The aim of the study was to investigate the feasibility and tumour response of intraperitoneal 5-Fluorouracil (5-FU) treatment in non-resectable pancreas cancer, using vasopressin to improve the pharmacokinetic profile. Further, to study the effect of vasopressin on peritoneal blood flow, altered by intraperitoneal 5-FU or the presence of peritoneal carcinomatosis. Methods: In the animal experiments, the 133Xe-clearance technique and as a comparison Laser doppler flow, were used to identify changes of peritoneal blood flow caused by vasopressin in unmanipulated animals and in animals with peritoneal carcinomatosis or animals given intraperitoneal 5-FU. In the clinical studies, 68 (39 women/29 men) patients, with a non-resectable ductal pancreas cancer and a Karnovsky Index ≥70 were included. Patients were treated with 750-1500 mg/m2 5-FU intraperitoneally through a Port-a-cath and Leucovorin 100 mg/m2 intravenously on two consecutive days every 21 days until progression. Seventeen patients, receiving 750 mg/m2 5-FU, were given concomitant vasopressin 0.1 IU/min during 180 minutes, alternatively day 1 or 2. Results: In the animal experiments, vasopressin 0.07 IU/kg/min significantly reduced the 133Xe-clearance. Intraperitoneal 5-FU decreased the basal peritoneal blood flow and abrogated the vasopressin effect for 1-2 days. The presence of peritoneal carcinomatosis did not influence the basal peritoneal blood flow, nor the reduction of peritoneal blood flow caused by vasopressin. In the clinical studies, the treatment with intraperitoneal 5-FU was well tolerated, with no WHO Grade 3 or 4 toxicity with doses up to 1250 mg/m2. Thirty patients achieved at least stable disease at three months. The median survival time was 8.0 (range 0.8-54.1) months. There was a significant reduction of 5-FU Cmax on day 2, but no significant reduction of AUC, when vasopressin was given. Conclusion: Peritoneal blood flow changes caused by vasopressin can be estimated with the 133Xe-clearance technique. Intraperitoneal 5-FU but not peritoneal carcinomatosis decreases the vasopressin induced 133Xe-clearance reduction, 1-2 days after administration. In patients with non-resectable pancreas cancer, intraperitoneal 5-FU up to 1250 mg/m2 for two days every third week can be given without WHO grade 3 and 4 toxicity. The treatment is well tolerated with few and minor side effects. Tumour responses were observed. Addition of vasopressin does not significantly enhance the pharmacokinetics of intraperitoneal 5-Flurorouracil, but adds toxicity.
250

In vivo and in vitro approaches to induce beta cells from stem and progenitor cells

Selander, Lars January 2009 (has links)
Diabetes or diabetes mellitus which is the correct medical term is a medical condition were the affected person lack the ability to regulate his or her blood glucose levels. This inability is directly due to the fact that the insulin producing cells, residing in the pancreas, can’t meet the body’s demand for insulin. It is estimated that close to 200 million people are suffering from diabetes today and this number is predicted to double within 20 years. Of the approximately 200 million people suffering from diabetes today approximately 20 million are in dependent on daily injections of insulin. Being dependent on exogenous insulin is not only an inconvenience it also increase the risk for several medical complications such as stroke, heart disorders, kidney failure, retinopathy, atherosclerosis and impaired wound healing. The major risk factor for all these complications is long periods of high blood sugar levels that is damaging to thin blood vessels and nerves.  Even in the best of situations the blood sugar levels of a diabetic with need for daily insulin injections can never be as well controlled as in a healthy individual. Increased understanding in the developmental processes behind the formation of the pancreas, and more specifically the insulin producing β-cells could result in new treatments for diabetics. By imitating the in vivo conditions generating pancreatic development scientist are now able to induce embryonic stem cells to differentiate into pancreatic progenitors as well as insulin producing β-cells in vitro. These in vitro generated pancreatic cells might in the future serve as a donor source for transplantations, thereby restoring the insulin producing capability of diabetic patients. An alternative approach to restore insulin production in diabetics is to influence cells in the pancreas to generate more insulin producing cells. To successfully achieve this, what cell types have the capacity to generate β-cells needs to be appreciated. In this thesis papers concerning in vitro differentiating of embryonic stem cells towards a pancreatic fate as well as in vivo studies in basic pancreas development are presented and discussed.

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