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Ubiquitination is a widespread post-translational modification that controls multiple steps in autophagy, a major lysosome-mediated intracellular degradation pathway. A variety of ubiquitin chains are attached as selective labels on protein aggregates and dysfunctional organelles, thus promoting their autophagy-dependent degradation. Moreover, ubiquitin modification of autophagy regulatory components is essential to positively or negatively regulate autophagy flux in both non-selective and selective pathways. We review the current findings that elucidate the components, timing, and kinetics of the multivalent role of ubiquitin signals in control of amplitude and selectivity of autophagy pathways as well as their impact on the development of human diseases.
The G2A receptor (GPR132) contributes to oxaliplatin-induced mechanical pain hypersensitivity
(2017)
Chemotherapy-induced peripheral neuropathic pain (CIPN) is a common and severe debilitating side effect of many widely used cytostatics. However, there is no approved pharmacological treatment for CIPN available. Among other substances, oxaliplatin causes CIPN in up to 80% of treated patients. Here, we report the involvement of the G-protein coupled receptor G2A (GPR132) in oxaliplatin-induced neuropathic pain in mice. We found that mice deficient in the G2A-receptor show decreased mechanical hypersensitivity after oxaliplatin treatment. Lipid ligands of G2A were found in increased concentrations in the sciatic nerve and dorsal root ganglia of oxaliplatin treated mice. Calcium imaging and patch-clamp experiments show that G2A activation sensitizes the ligand-gated ion channel TRPV1 in sensory neurons via activation of PKC. Based on these findings, we conclude that targeting G2A may be a promising approach to reduce oxaliplatin-induced TRPV1-sensitization and the hyperexcitability of sensory neurons and thereby to reduce pain in patients treated with this chemotherapeutic agent.
Background: High reproducibility and low intra- and interobserver variability are important strengths of cardiac magnetic resonance (CMR). In clinical practice a significant learning curve may however be observed. Basic CMR courses offer an average of 1.4 h dedicated to lecturing and demonstrating left ventricular (LV) function analysis. The purpose of this study was to evaluate the effect of initial teaching on complete and intermediate beginners’ quantitative measurements of LV volumes and function by CMR.
Methods: Standard clinical cine CMR sequences were acquired in 15 patients. Five observers (two complete beginners, one intermediate, two experienced) measured LV volumes. Before initial evaluation beginners read the SCMR guidelines on CMR analysis. After initial evaluation, beginners participated in a two-hour teaching session including cases and hands-on training, representative for most basic CMR courses, after which it is uncertain to what extent different centres provide continued teaching and feedback in-house. Dice Similarity Coefficient (DSC) assessed delineations. Agreement, accuracy, precision, repeatability and reliability were assessed by Bland-Altman, coefficient of variation, and intraclass correlation coefficient methods.
Results: Endocardial DSC improved after teaching (+0.14 ± 0.17;p < 0.001) for complete beginners. Low intraobserver variability was found before and after teaching, however with wide limits of agreement. Beginners underestimated volumes by up to 44 ml (EDV), 27 ml (ESV) and overestimated LVM by up to 53 g before teaching, improving to an underestimation of up to 9 ml (EDV), 7 ml (ESV) and an overestimation of up to 30 g (LVM) after teaching. For the intermediate beginner, however, accuracy was quite high already before teaching.
Conclusions: Initial teaching to complete beginners increases accuracy for assessment of LV volumes, however with high bias and low precision even after standardised teaching as offered in most basic CMR courses. Even though the intermediate beginner showed quite high accuracy already before teaching, precision did generally not improve after standardised teaching. To maintain CMR as a technique known for high accuracy and reproducibility and low intra- and inter-observer variability for quantitative measurements, internationally standardised training should be encouraged including high-quality feedback mechanisms. Objective measurements of training methods, training duration and, above all, quality of assessments are required.
Background
Cochlear Implants (CIs) provide near normal speech intelligibility in quiet environments to individuals suffering from sensorineural hearing loss. Perception of speech in situations with competing background noise and especially music appraisal however are still insufficient. Hence, improving speech perception in ambient noise and music intelligibility is a core challenge in CI research. Quantitatively assessing music intelligibility is a demanding task due to its inherently subjective nature. However, previous approaches have related electrophysiological measurements to speech intelligibility, a corresponding relation to music intelligibility, can be assumed. Recent studies have investigated the relation between results obtained from hearing performance tests and Spread of Excitations (SoEs) measurements. SoE functions are acquired by measuring Electrically Evoked Compound Action Potentials (ECAPs) which represent the electrical response generated in the neural structures of the auditory nerve. The parameters designed to describe SoE functions are used to estimate the dispersal of the electric field in the cochlea. The quality of spatial separation of the electrical field generated by adjacent electrodes are assumed to correlate with hearing performance measures.
Aim of study
This study investigated the relation of parameters derived by ECAP measurements and perceptive skills which aim to access the level of speech and music intelligibility in CI users. In addition, the ratings assessed in a questionnaire on self-rated music intelligibility were correlated to a test battery consisting of measures for speech reception threshold (SRT) in noise (Oldenburger Satztest (OLSA)) and music intelligibility (Adaptive Melody-Pattern-Discrimination Test (AMPDT)). We hypothesised that results from this test battery correlated to subjective ratings and measures describing SoE functions.
Methods
The patient collective covered 17 well-experienced bilateral CI listeners (8 females, 9 males) between the age of 14 and 77 years with a minimum CI experience of two years. Music enjoyment and self-rated musicality was evaluated by means of a questionnaire. The AMPDT included two psychoacoustic tests: timbre difference discrimination threshold (TDDT) and background contour discrimination threshold (BCDT). The accentuation of harmonics in a foreground melody created a background melody. Accentuation was realised by sound level increment, frequency detuning and onset asynchrony. Subjects had to detect target intervals comprising both foreground and background melody by discriminating timbre differences in a Three-Interval Three-Alternative Forced-Choice (3I3AFC) procedure. In a One-Interval Two-Alternative Forced-Choice (1I2AFC) procedure, subjects had to classify the background melody’s contour. SoE was measured via a spatial forward-masking paradigm. A basal, medial and apical recording electrode was measured. Probe electrodes were one electrode position apical to the recording. The width of normalised SoE functions was calculated at their 25 % and 50 % level (excitation distance (DIST)). Furthermore, exponential functions were calculated for SoE profiles with more than three data points for each side. The OLSA assessed SRT in noise. The noisy environment was presented through an array of four loudspeakers (MSNF). The Fastl noise-condition allows to make use of gap listening representing the temporal characteristics of speech as a fluctuating noise. The OLnoise-condition is a continuous noise resulting in a maximum portion of masking.
Results
We found that background melody contour classiffication (BCDT) is more challenging to CI users than the detection of small perceptual timbre differences (TDDT). Background melody contour classification was possible with harmonic accentuation by sound level increment whereas accentuation by onset asynchrony was more demanding. CI users failed in background melody contour classification obtained by frequency detuning. SRTs assessed in the OLSA were significantly lower in the OLnoise than in the Fastl noise masking condition. A number of N = 90 SoE functions were acquired from ECAP measurements, in which N = 48 showed a clearly present ECAP response. The DIST at the 25 % and 50 % level was narrower for the basal than for the apical and medial electrode. SoE functions showed asymmetric profiles with larger amplitudes towards the basal end of the cochlea. Correlation analysis between the AMPDT, OLSA and DISTs showed no significant correlation. Correlation analysis between the AMPDT, OLSA and the questionnaire’s results could not prove that musical activities (music listening, singing or playing instruments) improve music intelligibility. However, CI supply has restored the importance of music, self-rated musicality and musical enjoyment in this study’s subjects.
Conclusions
The present study’s results imply that CI listeners are only able to detect distinct timbre alterations throughout the course of a musical piece whereas they cannot discriminate background melodies hidden in a pattern of complex harmonic sounds. Furthermore, SoE measurements do not seem to be an adequate tool to predict neither speech nor music intelligibility in CI listeners, contrary to our initial hypothesis. This finding is consistent with a number of studies who did not find a correlation between music or speech intelligibility and channel interactions assessed by SoE measurements. It can be concluded that albeit CI supply restores musical enjoyment in patients with sensorineural hearing loss, music perception is still poor and does not significantly improve by regular musical activities such as listening to music, singing or playing instruments.
Background: Supracondylar fractures of the humerus are a common injury in pediatric traumatology. The most common operative therapy is closed reduction and percutaneous pinning using K-wires. Common complications associated with this entity are neurovascular lesions, especially of the brachial artery and the median nerve.
Methods: We report two cases of patients treated in our trauma-center with supracondylar fracture of the humerus (AO IV°) and neurovascular complications.
Results: Both patients underwent open revision and recovered completely in their further course.
Conclusion: We recommend detailed neurovascular examination initially and after reposition of the fracture. The threshold for open reduction in cases of irreducible fractures should be low. In the presence of neurovascular impairment an open revision is mandatory, even months after the initial Trauma.
The yeast Rcf1 protein is a member of the conserved family of proteins termed the hypoxia-induced gene (domain) 1 (Hig1 or HIGD1) family. Rcf1 interacts with components of the mitochondrial oxidative phosphorylation system, in particular the cytochrome bc1 (complex III)-cytochrome c oxidase (complex IV) supercomplex (termed III-IV) and the ADP/ATP carrier proteins. Rcf1 plays a role in the assembly and modulation of the activity of complex IV; however, the molecular basis for how Rcf1 influences the activity of complex IV is currently unknown. Hig1 type 2 isoforms, which include the Rcf1 protein, are characterized in part by the presence of a conserved motif, (Q/I)X3(R/H)XRX3Q, termed here the QRRQ motif. We show that mutation of conserved residues within the Rcf1 QRRQ motif alters the interactions between Rcf1 and partner proteins and results in the destabilization of complex IV and alteration of its enzymatic properties. Our findings indicate that Rcf1 does not serve as a stoichiometric component, i.e. as a subunit of complex IV, to support its activity. Rather, we propose that Rcf1 serves to dynamically interact with complex IV during its assembly process and, in doing so, regulates a late maturation step of complex IV. We speculate that the Rcf1/Hig1 proteins play a role in the incorporation and/or remodeling of lipids, in particular cardiolipin, into complex IV and. possibly, other mitochondrial proteins such as ADP/ATP carrier proteins.
OBJECTIVE: The role of supraglottic airway devices in emergency airway management is highlighted in international airway management guidelines. We evaluated the application of the new generation laryngeal tube suction (LTS-II/LTS-D) in the management of in-hospital unexpected difficult airway and cardiopulmonary resuscitation.
METHODS: During a seven-year period, patients treated with a laryngeal tube who received routine anesthesia and had an unexpected difficult airway (Cormack Lehane Grade 3-4), who underwent cardiopulmonary resuscitation, or who underwent cardiopulmonary resuscitation outside the operating room and had a difficult airway were evaluated. Successful placement of the LTS II/LTS-D, sufficient ventilation, time to placement, number of placement attempts, stomach content, peripheral oxygen saturation/end-tidal carbon dioxide development (SpO2/etCO2) over 5 minutes, subjective overall assessment and complications were recorded.
RESULTS: In total, 106 adult patients were treated using an LTS-II/LTS-D. The main indication for placement was a difficult airway (75%, n=80), followed by cardiopulmonary resuscitation (25%, n=26) or an overlap between both (18%, n=19). In 94% of patients (n=100), users placed the laryngeal tube during the first attempt. In 93% of patients (n=98), the tube was placed within 30 seconds. A significant increase in SpO2 from 97% (0-100) to 99% (5-100) was observed in the whole population and in cardiopulmonary resuscitation patients. The average initial etCO2 of 39.5 mmHg (0-100 mmHg) decreased significantly to an average of 38.4 mmHg (10-62 mmHg) after 5 minutes. A comparison of cardiopulmonary resuscitation patients with non-cardiopulmonary resuscitation patients regarding gastric contents showed no significant difference.
CONCLUSIONS: LTS-D/LTS-II use for in-hospital unexpected difficult airway management provides a secure method for primary airway management until other options such as video laryngoscopy or fiber optic intubation become available.
Background Microdeletions are known to confer risk to epilepsy, particularly at genomic rearrangement “hotspot” loci. However, deciphering their role outside hotspots and risk assessment by epilepsy sub-type has not been conducted.
Methods We assessed the burden, frequency and genomic content of rare, large microdeletions found in a previously published cohort of 1,366 patients with Genetic Generalized Epilepsy (GGE) plus two sets of additional unpublished genome-wide microdeletions found in 281 Rolandic Epilepsy (RE) and 807 Adult Focal Epilepsy (AFE) patients, totaling 2,454 cases. These microdeletion sets were assessed in a combined analysis and in sub-type specific approaches against 6,746 ethnically matched controls.
Results When hotspots are considered, we detected an enrichment of microdeletions in the combined epilepsy analysis (adjusted-P= 2.00×10-7; OR = 1.89; 95%-CI: 1.51-2.35), where the implicated microdeletions overlapped with rarely deleted genes and those involved in neurodevelopmental processes. Sub-type specific analyses showed that hotspot deletions in the GGE subgroup contribute most of the signal (adjusted-P = 1.22×10-12; OR = 7.45; 95%-CI = 4.20-11.97). Outside hotspot loci, microdeletions were enriched in the GGE cohort for neurodevelopmental genes (adjusted-P = 4.78×10-3; OR = 2.30; 95%-CI = 1.42-3.70), whereas no additional signal was observed for RE and AFE. Still, gene content analysis was able to identify known (NRXN1, RBFOX1 and PCDH7) and novel (LOC102723362) candidate genes affected in more than one epilepsy sub-type but not in controls.
Conclusions Our results show a heterogeneous effect of recurrent and non-recurrent microdeletions as part of the genetic architecture of GGE and a minor to negligible contribution in the etiology of RE and AFE.
Why do humans cooperate and often punish norm violations of others? In the present study, we sought to investigate the genetic bases of altruistic punishment (AP), which refers to the costly punishment of norm violations with potential benefit for other individuals. Recent evidence suggests that norm violations and unfairness are indexed by the feedback-related negativity (FRN), an anterior cingulate cortex (ACC) generated neural response to expectancy violations. Given evidence on the role of serotonin and dopamine in AP as well as in FRN-generation, we explored the impact of genetic variation of serotonin and dopamine function on FRN and AP behavior in response to unfair vs. fair monetary offers in a Dictator Game (DG) with punishment option. In a sample of 45 healthy participants we observed larger FRN amplitudes to unfair DG assignments both for 7-repeat allele carriers of the dopamine D4 receptor (DRD4) exon III polymorphism and for l/l-genotype carriers of the serotonin transporter gene-linked polymorphic region (5-HTTLRP). Moreover, 5-HTTLPR l/l-genotype carriers punished unfair offers more strongly. These findings support the role of serotonin and dopamine in AP, potentially via their influence on neural mechanisms implicated in the monitoring of expectancy violations and their relation to impulsive and punishment behavior.