The Experts below are selected from a list of 180 Experts worldwide ranked by ideXlab platform
Gabriela Da Silva Xavier - One of the best experts on this subject based on the ideXlab platform.
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the cells of the Islets of Langerhans
Journal of Clinical Medicine, 2018Co-Authors: Gabriela Da Silva XavierAbstract:Islets of Langerhans are islands of endocrine cells scattered throughout the pancreas. A number of new studies have pointed to the potential for conversion of non-β islet cells in to insulin-producing β-cells to replenish β-cell mass as a means to treat diabetes. Understanding normal islet cell mass and function is important to help advance such treatment modalities: what should be the target islet/β-cell mass, does islet architecture matter to energy homeostasis, and what may happen if we lose a particular population of islet cells in favour of β-cells? These are all questions to which we will need answers for islet replacement therapy by transdifferentiation of non-β islet cells to be a reality in humans. We know a fair amount about the biology of β-cells but not quite as much about the other islet cell types. Until recently, we have not had a good grasp of islet mass and distribution in the human pancreas. In this review, we will look at current data on islet cells, focussing more on non-β cells, and on human pancreatic islet mass and distribution.
Bo Nilsson - One of the best experts on this subject based on the ideXlab platform.
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control of instant blood mediated inflammatory reaction to improve Islets of Langerhans engraftment
Current Opinion in Organ Transplantation, 2011Co-Authors: Bo Nilsson, Kristina Nilsson Ekdahl, Olle KorsgrenAbstract:PURPOSE of REVIEW: Transplantation of Islets of Langerhans is an emerging treatment procedure for patients with severe type 1 diabetes, but despite recent progress the procedure is associated with ...
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damage to porcine Islets of Langerhans after exposure to human blood invitro or after intraportal transplantation to cynomologus monkeys protective effects of scr1 and heparin see comments
Transplantation, 2000Co-Authors: William Bennet, B Sundberg, Torbj Rn Lundgren, A Tibell, C G Groth, A Richards, David White, Graciela Elgue, Rolf Larsson, Bo NilssonAbstract:Damage to porcine Islets of Langerhans after exposure to human blood invitro, or after intraportal transplantation to cynomologus monkeys:protective effects of sCR1 and heparin [see comments]
Michael G Roper - One of the best experts on this subject based on the ideXlab platform.
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microfluidic system for generation of sinusoidal glucose waveforms for entrainment of Islets of Langerhans
Analytical Chemistry, 2010Co-Authors: Xinyu Zhang, Alix Grimley, Richard Bertram, Michael G RoperAbstract:A microfluidic system was developed to produce sinusoidal waveforms of glucose to entrain oscillations of intracellular [Ca2+] in Islets of Langerhans. The work described is an improvement to a previously reported device where two pneumatic pumps delivered pulses of glucose and buffer to a mixing channel. The mixing channel acted as a low pass filter to attenuate these pulses to produce the desired final concentration. Improvements to the current device included increasing the average pumping frequency from 0.83 to 3.33 Hz by modifying the on-chip valves to minimize adhesion between the PDMS and glass within the valve. The cutoff frequency of the device was increased from 0.026 to 0.061 Hz for sinusoidal fluorescein waves by shortening the length of the mixing channel to 3.3 cm. The value of the cutoff frequency was chosen between the average pumping frequency and the low frequency (∼0.0056 Hz) glucose waves that were needed to entrain the Islets of Langerhans. In this way, the pulses from the pumps were ...
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two color electrophoretic immunoassay for simultaneous measurement of insulin and glucagon content in Islets of Langerhans
Electrophoresis, 2008Co-Authors: Christelle Guillo, Michael G RoperAbstract:A multianalyte CE competitive immunoassay using two-color detection was developed to measure insulin and glucagon in Islets of Langerhans. Insulin was quantified with FITC-insulin (Ins*) and anti-insulin antibodies (Ins Ab) and glucagon was quantified with Cy5-glucagon (Glu*) and anti-glucagon antibodies (Glu Ab). A 3 mW Ar + laser at 488 nm and a 25 mW laser diode at 635 nm were used to excite FITC and Cy5, respectively. Fluorescence was split with a half-silvered mirror and passed through a 520 ± 20 nm bandpass filter or a 663 nm longpass filter for the detection of insulin and glucagon, respectively. The two-color detection format enabled independent quantitation of both analytes even with concentrations of insulin immunoassay reagents 20-fold higher than glucagon reagents. Simultaneous calibration curves were generated and used to determine insulin and glucagon content in Islets of Langerhans. Amounts of insulin and glucagon were 56.6 ± 3.2 and 1.0 ± 0.5 ng/islet, respectively. LODs were 7 nM insulin and 3 nM glucagon. The assay will be applicable to fast monitoring of multiple peptides secreted from Islets of Langerhans and can be applied to other systems for the quantitation of multiple analytes with large differences in concentrations.
Maria Stein - One of the best experts on this subject based on the ideXlab platform.
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nestin expressing cells in the pancreatic Islets of Langerhans
Biochemical and Biophysical Research Communications, 2000Co-Authors: Eric Hunziker, Maria SteinAbstract:Abstract The pancreatic Islets of Langerhans produce several peptide hormones, predominantly the metabolically active hormones insulin and glucagon, which are critical for maintaining normal fuel homeostasis. Some evidence exists that pancreatic endocrine cells turn over at a slow rate and can regenerate in certain conditions. This could be due to the presence of pluripotent cells residing in the pancreas. Recently the intermediate filament protein nestin has been identified to be a marker for a multipotent stem cell in the central nervous system. Given the similarity between the pancreatic Islets and neuronal cells, we hypothesized that stem cells expressing nestin might be present in the pancreas. Here we present evidence that a subset of cells in the pancreatic Islets express the stem cell marker nestin. These cells might serve as precursors of differentiated pancreatic endocrine cells.
Eckhard Lammert - One of the best experts on this subject based on the ideXlab platform.
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giving and taking endothelial and β cells in the Islets of Langerhans
Trends in Endocrinology and Metabolism, 2010Co-Authors: Daniel Eberhard, Martin Kragl, Eckhard LammertAbstract:The β-cells of the Islets of Langerhans are embedded in a dense capillary network. The blood vessels supply the islet cells with nutrients and oxygen, and in turn take up the secreted islet hormones to deliver them to target tissues. In addition, vessels provide a basement membrane, which optimizes islet function. In this review we focus on the dynamic interactions between blood vessels and β-cells, which are pivotal for enhancing insulin expression and β-cell proliferation in response to increased insulin demand during body growth, pregnancy, and virtually all conditions associated with insulin resistance. Importantly, a failure in this adaptive response might contribute to the onset of type 2 diabetes mellitus.
