| 1. |
- Bjorklund, Robert, et al.
(författare)
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Electrode specific information from voltammetric monitoring of biogas production
- 2010
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Ingår i: Talanta. - : Elsevier Science B.V., Amsterdam.. - 0039-9140 .- 1873-3573. ; 81:04-May, s. 1578-1584
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Tidskriftsartikel (refereegranskat)abstract
- A sensor employing pulse voltammetry monitored the liquid phase of a biogas reactor during 32 days of gas production An electrode allay consisting of stainless steel, platinum and rhodium electrodes generated current responses for a sequence of voltage pulses Plots of individual current responses against time indicated the electrochemical changes occurring in the broth from the perspective of each electrode. The responses from stainless steel had a pronounced diurnal oscillation which followed the daily introduction and consumption of substrate The current responses for platinum were in a narrow range whereas those for rhodium exhibited several minima A disturbance in the reactor caused by omission of substrate led to decreases in both gas production and current responses for all the electrodes Multivariate data evaluation of all the current responses by principal component analysis indicated the daily fluctuations for concentrations of ions and redox active compounds in the broth
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| 2. |
- Hals, Ingrid K., et al.
(författare)
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A 1-year pilot study of intralymphatic injections of GAD-alum in individuals with latent autoimmune diabetes in adults (LADA) with signs of high immunity: No safety concerns and resemblance to juvenile type 1 diabetes
- 2023
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Ingår i: Diabetes, obesity and metabolism. - : WILEY. - 1462-8902 .- 1463-1326. ; 25:11, s. 3400-3409
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To test, for the first time in latent autoimmune diabetes in adults (LADA), the effects of autoantigen-specific immunotherapy by intralymphatic administration of aluminium-formulated recombinant human glutamic acid decarboxylase 65 (GAD-alum); specifically, to test if this treatment is safe, to test whether it induces a strong immunological response akin to a similar protocol in type 1 diabetes and to look for associations with preserved beta-cell function. Materials and Methods: Three GAD-alum injections, 4 mu g each, were administered 1 month apart into an inguinal lymph node in 14 people with newly diagnosed LADA (age 30-62 years) presenting with high levels of antibodies against glutamic acid decarboxylase (GADA). Adverse effects, immunological variables and beta-cell function were monitored, with detailed measurements at 5 and 12 months from baseline. Results: Clinical adverse effects were minor and transient and measured laboratory variables were unaffected. All participants completed the study. Treatment raised levels of GADA, elicited strong effects on reactivity of peripheral blood mononuclear cells to GAD and raised cytokine/chemokine levels. Beta-cell function appeared stable preferentially in the seven participants carrying human leukocyte antigen (HLA) haplotypes DR3DQ2, as assessed by C-peptide glucagon tests (P < 0.05 vs. seven non-carriers). Conclusion: Intralymphatic treatment with GAD-alum in LADA is without clinical or other safety concerns over a 12-month period. As in a similar protocol used in type 1 diabetes, treatment exerts a strong immunological impact and is compatible with protection of beta-cell function preferentially in HLA-DR3DQ2 LADA patients. These findings pave the way for a randomized controlled trial in this important subgroup of LADA patients.
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| 3. |
- Krishnan, Kalaiselvan, et al.
(författare)
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Role of Transient Receptor Potential Melastatin-like Subtype 5 Channel in Insulin Secretion From Rat beta-Cells
- 2014
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Ingår i: Pancreas. - 0885-3177 .- 1536-4828. ; 43:4, s. 597-604
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Tidskriftsartikel (refereegranskat)abstract
- Objective Several studies have reported that the transient receptor potential melastatin-like subtype 5 (TRPM5) channel, a Ca2+-activated monovalent cation channel, is involved in the stimulus-secretion coupling in the mouse pancreatic beta-cells. We have studied the role of the TRPM5 channel in regulating insulin secretion and cytoplasmic free Ca2+ concentration ([Ca2+](i)) in the rat beta-cells by using triphenylphosphine oxide, a selective inhibitor of the channel. Methods Insulin secretion from islets from Sprague-Dawley rats was measured in batch incubations. Cytoplasmic free Ca2+ concentration was measured from single beta-cells by fura-2-based microfluorometry. Results Triphenylphosphine oxide did not alter insulin secretion and [Ca2+](i) response triggered by KCl or fructose. It inhibited insulin secretion in response to glucose, l-arginine, and glucagon-like peptide 1. It also inhibited glucose-induced insulin secretion by mechanisms that are independent of the adenosine triphosphate-sensitive potassium channels and [Ca2+](i) increase. Conclusions Our results suggest that in the rat islets, TRPM5 is involved in mediating insulin secretion by glucose and l-arginine and in potentiating the glucose-induced insulin secretion by glucagon-like peptide 1.
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| 4. |
- Ma, Zuheng, et al.
(författare)
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Evidence for Presence and Functional Effects of Kv1.1 Channels in beta-Cells: General Survey and Results from mceph/mceph Mice
- 2011
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Voltage-dependent K+ channels (Kv) mediate repolarisation of beta-cell action potentials, and thereby abrogate insulin secretion. The role of the Kv1.1 K+ channel in this process is however unclear. We tested for presence of Kv1.1 in different species and tested for a functional role of Kv1.1 by assessing pancreatic islet function in BALB/cByJ (wild-type) and megencephaly (mceph/mceph) mice, the latter having a deletion in the Kv1.1 gene. Methodology/Principal Findings: Kv1.1 expression was detected in islets from wild-type mice, SD rats and humans, and expression of truncated Kv1.1 was detected in mceph/mceph islets. Full-length Kv1.1 protein was present in islets from wildtype mice, but, as expected, not in those from mceph/mceph mice. Kv1.1 expression was localized to the beta-cell population and also to alpha-and delta-cells, with evidence of over-expression of truncated Kv1.1 in mceph/mceph islets. Blood glucose, insulin content, and islet morphology were normal in mceph/mceph mice, but glucose-induced insulin release from batch-incubated islets was (moderately) higher than that from wild-type islets. Reciprocal blocking of Kv1.1 by dendrotoxin-K increased insulin secretion from wild-type but not mceph/mceph islets. Glucose-induced action potential duration, as well as firing frequency, was increased in mceph/mceph mouse beta-cells. This duration effect on action potential in beta-cells from mceph/mceph mice was mimicked by dendrotoxin-K in beta-cells from wild-type mice. Observations concerning the effects of both the mceph mutation, and of dendrotoxin-K, on glucose-induced insulin release were confirmed in pancreatic islets from Kv1.1 null mice. Conclusion/Significance: Kv1.1 channels are expressed in the beta-cells of several species, and these channels can influence glucose-stimulated insulin release.
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