Search results for "Pancrea"
showing 10 items of 814 documents
Standardization of islet isolation outcome- A new automatic system to determine pancreatic islet viability
2011
Pancreatic islet transplantation is emerging as a therapeutic approach for patients affected by diabetes. This approach consists of a minimally invasive procedure replacing insulin-producing cells (pancreatic islets). The technique has been proven successful, but limitations have been identified. One of the major challenges of the procedure is the counting of the isolated pancreatic islets, which is currently jeopardized by subjectivity and inaccuracy. Determination of the accurate islet number is a crucial factor in determining the correlation between the isolation product and clinical outcome. In the proposed study, we have developed software capable of objectively evaluating islet number…
Review article: a comparison of glucagon-like peptides 1 and 2.
2013
Summary Background Recent advancements in understanding the roles and functions of glucagon-like peptide 1 (GLP-1) and 2 (GLP-2) have provided a basis for targeting these peptides in therapeutic strategies. Aim To summarise the preclinical and clinical research supporting the discovery of new therapeutic molecules targeting GLP-1 and GLP-2. Methods This review is based on a comprehensive PubMed search, representing literature published during the past 30 years related to GLP-1 and GLP-2. Results Although produced and secreted together primarily from L cells of the intestine in response to ingestion of nutrients, GLP-1 and GLP-2 exhibit distinctive biological functions that are governed by t…
Prolactin supplementation to culture medium improves beta-cell survival
2010
OBJECTIVES.: Recent studies demonstrated that prolactin (PRL) has beneficial effects on β cells for islet transplantation. We examined the effect of human recombinant PRL (rhPRL) supplementation to the culture media to determine its potential use in the context of clinical islet transplantation. MATERIALS AND METHODS.: Each human islet isolated from 14 deceased multiorgan donors was cultured in Miami modified media-1 supplemented with or without rhPRL (500 μg/L) for 48 hr. β-Cell survival and proliferation (BrdU and Ki-67) were determined by laser scanning cytometry. The cytoprotective effects of rhPRL against noxious stimuli were assessed by flow cytometry (tetramethylrhodamine ethyl ester…
Long-term function of porcine islets and single cells embedded in barium-alginate matrix.
1993
The influence of alginate-embedding on the maintenance of functioning and morphological integrity in long-term culture of isolated porcine islets and islet cells was studied. Free-floating islets and islet cells served for control. Function was tested after the 1st, 2nd and 4th week. Basal and glucose-stimulated insulin secretion of embedded islets decreased slightly, but significantly after the first week (from 4.39 +/- 0.64 to 2.87 +/- 0.47 at normal and from 11.96 +/- 1.44 to 4.76 +/- 0.78 microU pro 24 h pro islet at elevated glucose concentration, p < 0.05 and < 0.01, resp.) and remained unchanged thereafter. Glucose-stimulation resulted in significant increases in insulin secretion at…
GLP-2 as Beneficial Factor in the Glucose Homeostasis in Mice Fed a High Fat Diet
2015
Glucagon like peptide-2 (GLP-2) is a gastrointestinal hormone released in response to dietary nutrients, which acts through a specific receptor, the GLP-2 receptor (GLP-2R). The physiological effects of GLP-2 are multiple, involving also the intestinal adaptation to high fat diet (HFD). In consideration of the well-known relationship between chronic HFD and impaired glucose metabolism, in the present study we examined if the blocking of the GLP-2 signaling by chronic treatment with the GLP-2R antagonist, GLP-2 (3-33), leads to functional consequences in the regulation of glucose metabolism in HFD-fed mice. Compared with animals fed standard diet (STD), mice at the 10th week of HFD showed hy…
A new method to value efficiency of enzyme blends for pancreatic tissue digestion.
2010
Islet transplantation, since the 90’s, has been resulting to be one of the best successful example of human cell therapy. Nevertheless, islet isolation procedure is not completely standardized; in fact, more than fifty percent of islets procedures don’t arrive to their transplantation. This is due both to the variability of donor’s pancreas and to an unpredictable enzymatic blend efficiency. Enzymes used in pancreas digestion are extracted from Clostridium histolyticum bacteria and digest several substrates. In particular they have strong collagenolytic activity compared to vertebrate collagenases. However, several impediments persist in human islet isolation success probably due to the var…
Recovery of Endogenous β-Cell Function in Nonhuman Primates After Chemical Diabetes Induction and Islet Transplantation
2008
OBJECTIVE—To describe the ability of nonhuman primate endocrine pancreata to reestablish endogenous insulin production after chemical β-cell destruction. RESEARCH DESIGN AND METHODS—Eleven monkeys (Macaca fascicularis) were rendered diabetic with streptozotocin. Eight diabetic monkeys received intraportal porcine islet transplantation. RESULTS—Two monkeys transplanted after 75 days of type 1 diabetes showed recovery of endogenous C-peptide production a few weeks after transplantation, concomitant with graft failure. Histological analysis of the pancreas of these monkeys showed insulin-positive cells, single or in small aggregates, scattered in the pancreas and adjacent to ducts. Interesting…
Protection of islets in culture by delivery of oxygen binding neuroglobin via protein transduction.
2005
Islet transplantation has become an accepted method to treat type 1 diabetes. To succeed and achieve normal levels of glucose in transplant recipients, the quality of the transplanted islets is of the utmost importance. Lack of oxygen during organ procurement, islet isolation, and subsequent culture triggers apoptosis or necrosis and loss of islet function, causing the yield and quality to diminish. A promising candidate for cytoprotection against oxygen deprivation is neuroglobin (Ngb). Ngb is a recently described member of globin family and is expressed in neurons, retina, and pancreatic islets. To overexpress this protein in the islets and study its ability to protect them, we utilized p…
Impact of biliary stents on the diagnostic accuracy of EUS-guided fine-needle biopsy of solid pancreatic head lesions: A multicenter study
2021
Background and Objectives: There is no clear evidence of a negative impact of biliary stents on the diagnostic yield of EUS-guided fine-needle biopsy (EUS-FNB) for diagnosing pancreatic head lesions. We aimed to evaluate the association between the presence of biliary stents and the diagnostic accuracy of EUS-FNB. Materials and Methods: A multicenter retrospective study including all jaundiced patients secondary to pancreatic head masses was performed. Patients were divided into two groups according to the presence of a biliary stent placed before EUS-FNB. Pathological results were classified according to the Papanicolaou classification and compared against the final diagnosis. Diagnostic m…
A new method to valued efficiency of enzyme blends for pancreas tissue digestion
2009
One of the best successful examples of cell therapy is represented by islet transplantation since 1990. However islet isolation methods are not completely standardized yet. More than half of isolation procedures failed to isolate adequate islets for transplantation, due to variable pancreas conditions and to unpredictable enzymatic blend efficiency. Enzymes used for pancreas digestion include collagenases and neutral proteases: their composition and activity are largely variable between different batches. We set up a new in vitro method to better in vitro characterize enzymatic blend before its use in human pancreas. In our experimental approach human immortalized cells (ECV-304) or human is…