The Calcium-dependent Potassium Current in Olfactory Interneurons of the Cockroach Periplaneta americana

The olfactory system of insects has already served as a suitable model to investigate mechanisms of general information processing. Thus, insect olfactory neurons were used to study physiology, transmitter content, from that evoked currents as well as sensory processing on a network level. As an important step towards understanding how distinct electrophysiological properties of neurons are generated by intrinsic currents, I used whole-cell patch-clamp recordings to analyze biophysical and pharmacological properties of the calcium-dependent potassium current (IK(Ca)) from unequivocally identified uniglomerular projection neurons (uPNs) and local interneurons (LNs) in the adult, intact brain of the cockroach Periplaneta americana. Steady-state activation at defined intracellular Ca2+ concentrations ([Ca2+]i] revealed highest Ca2+-sensitivity of IK(Ca) from type I LN, IK(Ca) from other AL interneurons require at least 10 fold higher [Ca2+]i to activate at physiological membrane potential. IK(Ca) from all AL interneurons was clearly dependent on voltage and calcium, while biophysical properties of IK(Ca) delineate distinct qualities in calcium dependent activation. While IK(Ca) from type I LNs is rigidly activated in response to Ca2+ influx, biophysical properties of IK(Ca) from uPNs, and type II LNs suggest a beneficial effect by ICa activation. Steady-state activation with simultaneous Ca2+ influx revealed that IK(Ca) is active at subthreshold potential and high extracellular Ca2+ concentration ([Ca2+]O) uncoupled IK(Ca) activation from ICa in uPNs, type IIb LNs, and the major part of type IIa LNs. A remarkable high current density of IK(Ca) was found in uPNs, whereas in type I LNs the slowest time course of Ca2+-dependent activation was observed. Although IK(Ca) from all AL interneurons is activated at subthreshold potential, buffering the membrane potential after excitatory Ca2+ influx, current-clamp recordings of spiking AL interneurons preclude an impact of IK(Ca) on membrane resting potential. Within the population of type II LNs, the quality of biophysical properties varied within the range bounded by uPNs and type I LNs. Whereby IK(Ca) from type IIb LNs displayed fastest time course of Ca2+ dependent activation and inactivation. In type IIa LN population greatest variability of data was observed, which might arise from different subtypes of type IIa LNs. However, differential Ca2+ sensitivity could not be assigned to KCa channel subtypes. IK(Ca) from all AL interneurons were insensitive to the SK channel blocker apamin, whereas charybdotoxin(ChTX) achieved complete inhibition of IK(Ca) yielding in an EC50 of 2 nM for uPNs and 4 nM for both type I and type II LNs. Iberiotoxin, a BK channel specific inhibitor displayed similar but less potent effects than ChTX, suppressing only a fraction of IK(Ca) in all AL interneurons even at the highest applied concentration. Biophysical properties of IK(Ca) delineate distinct qualities in calcium sensitivity and Ca2+ dependent as well as voltage dependent activation, even though IK(Ca) seems to be mediated by BK channels in all types of AL interneurons

Austrian model approach to assess quality of post-mortem feedback-information systems in pigs

A novel quality assurance approach was tested for its applicability to assess data validity and meat inspection performance by means of modeling and training of official meat inspectors (OMIs). General linear mixed models (GLMM) were used to estimate the variance in 20 selected lesions assessed by 12 official meat inspectors for 247.507 pigs

Identification of the Amino Acids 300–600 of IRS-2 as 14-3-3 Binding Region with the Importance of IGF-1/Insulin-Regulated Phosphorylation of Ser-573

Phosphorylation of insulin receptor substrate (IRS)-2 on tyrosine residues is a key event in IGF-1/insulin signaling and leads to activation of the PI 3-kinase and the Ras/MAPK pathway. Furthermore, phosphorylated serine/threonine residues on IRS-2 can induce 14-3-3 binding. In this study we searched IRS-2 for novel phosphorylation sites and investigated the interaction between IRS-2 and 14-3-3. Mass spectrometry identified a total of 24 serine/threonine residues on IRS-2 with 12 sites unique for IRS-2 while the other residues are conserved in IRS-1 and IRS-2. IGF-1 stimulation led to increased binding of 14-3-3 to IRS-2 in transfected HEK293 cells and this binding was prevented by inhibition of the PI 3-kinase pathway and an Akt/PKB inhibitor. Insulin-stimulated interaction between endogenous IRS-2 and 14-3-3 was observed in rat hepatoma cells and in mice liver after an acute insulin stimulus and refeeding. Using different IRS-2 fragments enabled localization of the IGF-1-dependent 14-3-3 binding region spanning amino acids 300–600. The 24 identified residues on IRS-2 included several 14-3-3 binding candidates in the region 300–600. Single alanine mutants of these candidates led to the identification of serine 573 as 14-3-3 binding site. A phospho-site specific antibody was generated to further characterize serine 573. IGF-1-dependent phosphorylation of serine 573 was reduced by inhibition of PI 3-kinase and Akt/PKB. A negative role of this phosphorylation site was implicated by the alanine mutant of serine 573 which led to enhanced phosphorylation of Akt/PKB in an IGF-1 time course experiment. To conclude, our data suggest a physiologically relevant role for IGF-1/insulin-dependent 14-3-3 binding to IRS-2 involving serine 573

The statistical analysis plan for the unification of treatments and interventions for tinnitus patients randomized clinical trial (UNITI-RCT)

Background Tinnitus is a leading cause of disease burden globally. Several therapeutic strategies are recommended in guidelines for the reduction of tinnitus distress; however, little is known about the potentially increased effectiveness of a combination of treatments and personalized treatments for each tinnitus patient. Methods Within the Unification of Treatments and Interventions for Tinnitus Patients project, a multicenter, randomized clinical trial is conducted with the aim to compare the effectiveness of single treatments and combined treatments on tinnitus distress (UNITI-RCT). Five different tinnitus centers across Europe aim to treat chronic tinnitus patients with either cognitive behavioral therapy, sound therapy, structured counseling, or hearing aids alone, or with a combination of two of these treatments, resulting in four treatment arms with single treatment and six treatment arms with combinational treatment. This statistical analysis plan describes the statistical methods to be deployed in the UNITI-RCT. Discussion The UNITI-RCT trial will provide important evidence about whether a combination of treatments is superior to a single treatment alone in the management of chronic tinnitus patients. This pre-specified statistical analysis plan details the methodology for the analysis of the UNITI trial results. Trial registration ClinicalTrials.gov NCT04663828. The trial is ongoing. Date of registration: December 11, 2020. All patients that finished their treatment before 19 December 2022 are included in the main RCT analysis

Austrian model approach to assess quality of post-mortem feedback-information systems in pigs

A novel quality assurance approach was tested for its applicability to assess data validity and meat inspection performance by means of modeling and training of official meat inspectors (OMIs). General linear mixed models (GLMM) were used to estimate the variance in 20 selected lesions assessed by 12 official meat inspectors for 247.507 pigs.</p

Austrian model approach to assess quality of post-mortem feedback-information systems in pigs

A novel quality assurance approach was tested for its applicability to assess data validity and meat inspection performance by means of modeling and training of official meat inspectors (OMIs). General linear mixed models (GLMM) were used to estimate the variance in 20 selected lesions assessed by 12 official meat inspectors for 247.507.pigs. The pigs originated from 72 conventional farms and were slaughtered at one abattoir in Austria in the period January 2008 to June 2011.</p