Search results for "Pancreatic islets."
showing 10 items of 26 documents
Glucagon-like peptide-2 treatment improves glucose dysmetabolism in mice fed a high fat diet
2016
Previous studies suggested that endogenous glucagon-like peptide 2 (GLP-2) is dispensable for the regulation of glucose homeostasis under normal conditions, while it can play a beneficial role in obesity conditions. The purpose of the present study was to investigate whether chronic treatment with Gly2-GLP-2, a stable analogue of GLP-2, can have an impact on glycaemic and lipid control in mice fed a high-fat diet (HFD), an animal model of human obesity and insulin resistance. HFD mice were treated once a day with Gly2-GLP-2 for 4 weeks. Body weight, food intake, fasting glucose, intraperitoneal glucose tolerance, insulin-induced glucose clearance, glucose-stimulated insulin secretion, β-cel…
Senile amyloidosis: Principles of localization in a heterogeneous form of amyloidosis
1983
In order to identify amyloid deposits in patients over 60 years of age (so-called senile amyloid), the following five tissues were investigated under the light and electron microscope : 1. pituitary gland, 2. pancreatic islets of Langerhans, 3. heart, 4. aorta, and 5. brain. In all an increasing incidence of amyloid deposits was found with increasing age, and in the brain a significant quantitative increase in amyloid deposits with increasing age was observed. Despite the biochemical heterogeneity of amyloid found in old age, all the deposits seen in tissues examined were morphologically similar. Typical amyloid fibrils were always found (diameter 60–100 A), and these were invariably deposi…
Transcriptional profiling reveals functional links between RasGrf1 and Pttg1 in pancreatic beta cells
2014
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License .
A mouse model of in vivo chemical inhibition of retinal calcium-independent phospholipase A2 (iPLA2).
2013
International audience; Numerous studies have reported the implication of calcium-independent phospholipase A2 (iPLA2) in various biological mechanisms. Most of these works have used in vitro models and only a few have been carried out in vivo on iPLA2(-/-) mice. The functions of iPLA2 have been investigated in vivo in the heart, brain, pancreatic islets, and liver, but not in the retina despite its very high content in phospholipids. Phospholipids in the retina are known to be involved in several various key mechanisms such as visual transduction, inflammation or apoptosis. In order to investigate the implication of iPLA2 in these processes, this work was aimed to build an in vivo model of…
Diabetic Goto Kakizaki rats as well as type 2 diabetic patients show a decreased diurnal serum melatonin level and an increased pancreatic melatonin-…
2006
There are functional inter-relationships between the beta cells of the endocrine pancreas and the pineal gland, where the synchronizing circadian molecule melatonin originates. The aim of this study was to elucidate a putative interaction between insulin and melatonin in diabetic patients and a diabetic rat model. We analyzed glucose, insulin, and melatonin levels of type 2 patients, as well as type 2 diabetic Goto Kakizaki (GK) rats by radioimmunoassay. Expression of pancreatic melatonin and pineal insulin receptors, as well as arylalkylamine-N-acetyltransferase (AANAT), was determined by real-time reverse transcriptase polymerase chain reaction (RT-PCR). The AANAT enzyme activity was meas…
Multilayer capsules: a promising microencapsulation system for transplantation of pancreatic islets
2001
In 1980, Lim and Sun introduced a microcapsule coated with an alginate/polylysine complex for encapsulation of pancreatic islets. Characteristic to this type of capsule is, that it consists of a plain membrane which is formed during a single procedural step. With such a simple process it is difficult to obtain instantly a membrane optimized with respect to all the properties requested for islet transplantation. To overcome these difficulties, it is recommended to build up the membrane in several consecutive steps, each optimized for a certain property. In this study, we have analysed such a multilayer microcapsule for the encapsulation of pancreatic islets. Therefore, empty and islet contai…
Vascular Endothelial Growth Factor-Releasing Microspheres Based on Poly(ε-Caprolactone-PEG-ε-Caprolactone)-b-Poly(L-Lactide) Multiblock Copolymers In…
2020
Pancreatic islet transplantation is a promising advanced therapy that has been used to treat patients suffering from diabetes type 1. Traditionally, pancreatic islets are infused via the portal vein, which is subsequently intended to engraft in the liver. Severe immunosuppressive treatments are necessary, however, to prevent rejection of the transplanted islets. Novel approaches therefore have focused on encapsulation of the islets in biomaterial implants which can protect the islets and offer an organ-like environment. Vascularization of the device’s surface is a prerequisite for the survival and proper func- tioning of transplanted pancreatic islets. We are pursuing a prevascularization s…
Multipotential nestin and Isl-1 positive mesenchymal stem cells isolated from human pancreatic islets.
2006
Mesenchymal cells in the developing pancreas express the neural stem cell marker nestin and the transcription factor islet-1 (Isl-1). Using defined culture conditions we isolated on a single cell basis nestin producing cells from human pancreatic islets. These cells were immortalized with lentiviral vectors coding for telomerase and mBmi. They are positive for Isl-1 and nestin and have the potential to adopt a pancreatic endocrine phenotype with expression of critical transcription factors including Ipf-1, Isl-1, Ngn-3, Pax4, Pax6, Nkx2.2, and Nkx6.1 as well as the islet hormones insulin, glucagon, and somatostatin. In addition, they can be differentiated into human albumin producing cells …
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…
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…