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Cytotoxic effects of a thiol reactive ferritin compound on isolated pancreatic β cells and the protective action of L cysteine

The effects of an electron dense thiol reagent, Hg phenylazo ferritin, on β cell ultrastructure was studied in cell suspensions from mouse pancreatic islets. This type of thiol reagent induced severe damage in the β cells. The ferritin particles were traced with the electron microscope and found to be bound to the plasma membrane as well as to various cytoplasmic structures. The β cell cytotoxic a

Effects of pancreozymin and secretin on insulin release and the role of the exocrine pancreas

Mouse pancreatic islets microdissected free from, or surrounded by, exocrine cells were used to study the effects of secretin and choleeystokinm-pancreozymin on insulin release. Both secretin and cholecystokinin-pancreozymin potentiated glucose-stimulated insulin release regardless of whether exocrine cells were present. The results fail to support the idea that the presence of the exocrine parenc

The preparation of, and studies on, free cell suspensions from mouse pancreatic islets

Pancreatic islets, isolated from the pancreas of obese-hyperglycemic mice, were used to prepare free islet cells in suspension. Batches of 100 islets were disrupted by mechanical shaking for 10 sec in a Ca2+-free HEPES-buffered Krebs-Ring'er medium containing 1 mM EGTA. From 200-500 islets, about 2.2×106 cells could be obtained in suspension, corresponding to a yield of roughly 55% as calculated f

Assessment of Ultra-Short Heart Variability Indices Derived by Smartphone Accelerometers for Stress Detection

Body acceleration due to heartbeat-induced reaction forces can be measured as mobile phone accelerometer (m-ACC) signals. Our aim was to test the feasibility of using m-ACC to detect changes induced by stress by ultra-short heart rate variability (USV) indices (standard deviation of normal-to-normal interval-SDNN and root mean square of successive differences-RMSSD). Sixteen healthy volunteers wer

Influence of the mutation "diabetes" on insulin release and islet morphology in mice of different genetic backgrounds

Mice, 7-8-mo old, of the C57BL/KsJ-db strain and homozygotic for the mutant gene db, exhibited marked hyperglycemia and moderately elevated serum insulin levels. Light and electron microscopy provided evidence of a slightly decreased proportion of β cells in the pancreatic islets, irregular islet architecture with intraislet ducts, and degenerative as well as hypertrophic changes in the individua

The pancreatic β-cell recognition of insulin secretagogues. VIII. Comparisons of glucose with glyceraldehyde isomers and dihydroxyacetone

d-Glyceraldehyde stimulated the release of insulin from pancreatic islets of Umeå- ob ob-mice whether or not glucose was present in the medium. Like the action of glucose, that of d-glyceraldehyde was biphasic in time, exhibited a sigmoidal dose-response relationship, was potentiated by theophylline, arginine, iodoacetamide, or l-glyceraldehyde, and was inhibited by epinephrine, 2,4-dinitrophenol,

The pancreatic β cell recognition of insulin secretagogues. Influence of neuraminidase treatment on the release of insulin and the islet content of insulin, sialic acid, and cyclic adenosine 3':5' monophosphate

Pancreatic islets rich in β cells and microdissected from noninbred ob/ob mice contained about 15 pmol sialic acid per μg dry weight as determined by a microversion of the Warren thiobarbituric acid method. Removal of half of the sialic acid by treatment with Clostridium perfringens neuraminidase had no effect on the islet content of insulin, moderately inhibited glucose oxidation, and resulted in

Content of adenosine 3′:5′-cyclic monophosphate in the pancreatic islets of mice with a hereditary defect of insulin secretion

Glucose (20 mM) released insulin from pancreatic islets of C57BL 6J- db2J db2J mice, the response being potentiated by 1 mM 3-isobutyl-1-methylxanthine. Islets of C57BL KsJ- db db mice failed to respond to glucose and released only little insulin when challenged with both glucose and methylxanthine. After incubation with 0 or 20 mM glucose alone the islet content of adenosine 3′:5′-cyclic monophos

The pancreatic β-cell recognition of insulin secretagogues XIII effects of sulphydryl reagents on cyclic AMP

Chloromercuribenzene-p-sulphonic acid (0.1 mM) or 5,5′-dithiobis-(2-nitrobenzoic acid) (1 mM) alone had no effect on cyclic AMP in microdissected pancreatic islets of non-inbred ob/ob mice. In the presence of 1 mM 3-isobutyl-1-methylxanthine, the mercurial increased and the disulphide decreased the cyclic AMP content. Both sulphydryl reagents stimulated insulin release whether 3-isobutyl-1-methylx

The role of cross-linking in the scratch resistance of organic coatings: an investigation using atomic force microscopy

Understanding how the composition of organic coatings influences their ability to resist surface damage during use remains a challenge. A relevant potential influence is that of cross-linking density. This parameter is frequently used for tailoring the mechanical properties of organic coatings and it manifests itself in terms of scratch resistance. However, the mechanisms that influence scratch re

Atomically sharp, crystal phase defined GaAs quantum dots

Crystal phase defined heterostructures, or polytype heterostructures, are atomically sharp with no intermixing, which makes them ideal contenders for a wide number of applications. Although polytype quantum dots have shown promising results as single photon sources, a high degree of control on the dimensions and number of polytype quantum dots is necessary before any application can be developed.I

LOVE a Pairing

The problem of securely outsourcing the computation of a bilinear pairing has been widely investigated in the literature. Designing an efficient protocol with the desired functionality has, however, been an open challenge for a long time. Recently, Di Crescenzo et al. (CARDIS’20) proposed the first suite of protocols for securely and efficiently delegating pairings with online inputs under the pre

Humidity-Induced Phase Transitions of Surfactants Embedded in Latex Coatings Can Drastically Alter Their Water Barrier and Mechanical Properties

Latex coatings are environmentally friendly i.e., they are formed from aqueous polymer dispersions, are cheap to produce and provide exceptional mechanical properties. Therefore, they are ubiquitous and can be found in a wide range of different applications such as paints and varnishes, pressure-sensitive adhesives, textiles, construction materials, paper coatings and inks. However, they also have

Whose Freedom is it Anyway? The Fundamental Rights of Companies in EU Law

Companies enjoy increasingly extensive protection of their fundamental right to conduct business under EU law. This article will examine whether this protection is justified by reference to the foundational value of human freedom. In other words, does the way in which EU law protects the fundamental rights of companies to conduct business promote the freedom of individuals human beings within the

Comparison of the prevalence of glutamic acid decarboxylase (GAD65) and gliadin antibodies (AGA) in a randomly selected adult estonian population

We aimed to test the hypothesis that gluten might be associated with the development of islet cell autoimmunity. A random sample of 200 persons (87 males, mean age 42.4 years) from Estonia including one patient with type I diabetes mellitus was studied. IgG-type glutamic acid decarboxylase (GAD65) antibodies were determined using radioligand-binding assay and IgG/IgA-type gliadin antibodies (AGA)

Using Human Genetics to Understand Mechanisms in Ischemic Stroke Outcome : From Early Brain Injury to Long-Term Recovery

There is a critical need to elucidate molecular mechanisms underlying brain injury, repair, and recovery following ischemic stroke-a global health problem with major social and economic impact. Despite 5 decades of intensive research, there are no widely accepted neuroprotective drugs that mitigate ischemic brain injury, or neuroreparative drugs, or personalized approaches that guide therapies to