ECFS standards of care on CFTR-related disorders: Identification and care of the disorders

This is the third paper in the series providing updated information and recommendations for people with cystic fibrosis transmembrane conductance regulator (CFTR)-related disorder (CFTR-RD). This paper covers the individual disorders, including the established conditions - congenital absence of the vas deferens (CAVD), diffuse bronchiectasis and chronic or acute recurrent pancreatitis - and also other conditions which might be considered a CFTR-RD, including allergic bronchopulmonary aspergillosis, chronic rhinosinusitis, primary sclerosing cholangitis and aquagenic wrinkling. The CFTR functional and genetic evidence in support of the condition being a CFTR-RD are discussed and guidance for reaching the diagnosis, including alternative conditions to consider and management recommendations, is provided. Gaps in our knowledge, particularly of the emerging conditions, and future areas of research, including the role of CFTR modulators, are highlighted.

Pulmonary Aspergillosis in People with Cystic Fibrosis

In the last decade, fungal respiratory diseases have been increasingly investigated for their impact on the clinical course of people with cystic fibrosis (CF), with a particular focus on infections caused by Aspergillus spp. The most common organisms from this genus detected from respiratory cultures are Aspergillus fumigatus and Aspergillus terreus, followed by Aspergillus flavus, Aspergillus niger, and Aspergillus nidulans. These species have been identified to be both chronic colonizers and sources of active infection and may negatively impact lung function in people with CF. This review article discusses definitions of aspergillosis, challenges in clinical practice, and current literature available for laboratory findings, clinical diagnosis, and treatment options for pulmonary diseases caused by Aspergillus spp. in people with CF.

Manifestation and staging of arthropathy in cystic fibrosis. Defining different stages of cystic fibrosis arthropathy using ultrasound imaging and clinical scoring

BACKGROUND

The true prevalence of cystic fibrosis arthropathy (CFA) remains unclear and may be significantly higher than previously reported. In recent studies, joint symptoms have been reported in up to 30% of adults with CF. This underlines the importance of CFA as a rising and clinically relevant co-morbidity. A clear definition of CFA is yet missing and its pathogenesis remains unclear. We investigated the clinical manifestation of CFA particularly via ultrasound (US) examination to define and implement a staging for clinical assessment.

METHODS

In a prospective cohort study between March 2018 and February 2020 a total of 98 consecutively recruited, adult cystic fibrosis (CF) patients underwent joint-US examination according to a newly developed ultrasound score (US-CFA). A clinical assessment including rheumatological scores (DAS28, HAQ) has been conducted as well as a specially designed questionnaire. Investigation on clinical and microbiological data, as well as a comprehensive laboratory analysis, were carried out. Cluster analysis has been performed to detect patterns defining different CFA stages based on disease activity.

RESULTS

US imaging has shown a considerable incidence of mild to moderate effusion as sign of joint inflammation/(teno-)synovitis. K-means clustering was used to distinguish 3 different stages of CFA based on the intensity of the detected effusion. These stages showed a significant association with disease activity (DAS28, p = 0.0004) as well as with patient-reported symptoms such as total weeks of CFA per year (p = 0.004), acute CFA (p = 0.015), chronic CFA (p = 0.016), disease burden (p = 0.04). Based on the US-CFA, 16% of patients suffered from severe CFA (II), 51% from intermediate CFA (I) and 33% did not present detectable arthritis. Positive serology for Chlamydophilia pneumoniae (IgA, IgG) and Chlamydia trachomatis (IgA, IgG) significantly correlated with the US-CFA.

CONCLUSIONS

The results of this study show that a definition and categorization for the clinical manifestation of CFA can be described through US examination, which is able to detect disease activity concordant with the DAS28 as a validated clinical score on arthritis. Defining these stages will lead to a better understanding of the clinical phenotype of the disease and will optimize diagnosis, therapy and research on CFA in the future.

Activity in Barrel Cortex Related to Trace Eyeblink Conditioning

In mammals several memory systems are responsible for learning and storage of associative memory. Even apparently simple behavioral tasks, like pavlovian conditioning, have been suggested to engage, for instance, implicit and explicit memory processes. Here, we used single-whisker tactile trace eyeblink conditioning (TTEBC) to investigate learning and its neuronal bases in the mouse barrel column, the primary neocortical tactile representation of one whisker. Behavioral analysis showed that conditioned responses (CRs) are spatially highly restricted; they generalize from the principal whisker only to its direct neighbors. Within the respective neural representation, the principal column and its direct neighbors, spike activity showed a learning-related spike rate suppression starting during the late phase of conditioning stimulus (CS) presentation that was sustained throughout the stimulus-free trace period (Trace). Trial-by-trial analysis showed that learning-related activity was independent from the generation of eyelid movements within a trial, and set in around the steepest part of the learning curve. Optogenetic silencing of responses and their learning-related changes during CS and Trace epochs blocked CR acquisition but not its recall after learning. Silencing during the Trace alone, which carried major parts of the learning-related changes, had no effect. In summary, we demonstrate specific barrel column spike rate plasticity during TTEBC that can be partially decoupled from the CR, the learned eye closure, a hallmark of implicit learning. Our results, thus, point to a possible role of the barrel column in contributing to other kinds of memory as well.

Combining treatment for chronic hepatitis C with opioid agonist therapy is an effective microelimination strategy for people who inject drugs with high risk of non-adherence to antiviral therapy

Background & aims

Despite effective direct-acting antivirals (DAAs), hepatitis C virus (HCV) prevalence is high among people who inject drugs (PWIDs) and non-adherence to therapy remains a major obstacle towards HCV elimination in this subpopulation. To overcome this issue, we have combined ongoing opioid agonist therapy (OAT) with DAAs in a directly-observed therapy (DOT) setting.

Method

From September 2014 until January 2021 PWIDs at high risk of non-adherence to DAA therapy, who were also on OAT, were included into this microelimination project. Individuals received their OAT and DAAs under supervision of healthcare workers as DOT in a pharmacy or low-threshold facility.

Results

In total, 504 HCV RNA-positive PWIDs on OAT (387 men, 76.8%; median age: 38 years [IQR 33-45], HIV: 4.6%; hepatitis B: 1.4%) were included into this study. Two thirds reported ongoing intravenous drug use (IDU) and half of them had no permanent housing. Only 41 (8.1%) were lost to follow-up and two (0.4%) died of reasons unrelated to DAA toxicity. Overall, 90.7% of PWIDs achieved sustained virological response 12 weeks after treatment (SVR12) (95% CI: 88.1-93.2%). By excluding those lost to follow-up and hose who had died of causes unrelated to DAAs, the SVR12 rate was 99.1% (95% CI: 98.3-100.0%; modified intention-to-treat analysis). Four PWIDs (0.9%) experienced treatment failure. Over a median follow-up of 24 weeks (IQR 12-39), 27 reinfections (5.9%) were observed in individuals with the highest IDU rates (81.2%). Importantly, even though some were lost to follow-up, all completed their DAA treatment. By using DOT, adherence to DAAs was excellent with only a total of 86 missed doses (0.3% of 25,224 doses).

Conclusions

In this difficult-to-treat population of PWIDs with high rates of IDU , coupling DAA treatment to OAT in a DOT setting resulted in high SVR12 rates equivalent to conventional treatment settings in non-PWID populations.

Heterogeneity of management practices surrounding operable gallbladder cancer - results of the OMEGA-S international HPB surgical survey

BACKGROUND

Gallbladder cancer (GBC) is an aggressive, uncommon malignancy, with variation in operative approaches adopted across centres and few large-scale studies to guide practice. We aimed to identify the extent of heterogeneity in GBC internationally to better inform the need for future multicentre studies.

METHODS

A 34-question online survey was disseminated to members of the European-African Hepatopancreatobiliary Association (EAHPBA), American Hepatopancreatobiliary Association (AHPBA) and Asia-Pacific Hepatopancreatobiliary Association (A-PHPBA) regarding practices around diagnostic workup, operative approach, utilization of neoadjuvant and adjuvant therapies and surveillance strategies.

RESULTS

Two hundred and three surgeons responded from 51 countries. High liver resection volume units (>50 resections/year) organised HPB multidisciplinary team discussion of GBCs more commonly than those with low volumes (p < 0.0001). Management practices exhibited areas of heterogeneity, particularly around operative extent. Contrary to consensus guidelines, anatomical liver resections were favoured over non-anatomical resections for T3 tumours and above, lymphadenectomy extent was lower than recommended, and a minority of respondents still routinely excised the common bile duct or port sites.

CONCLUSION

Our findings suggest some similarities in the management of GBC internationally, but also specific areas of practice which differed from published guidelines. Transcontinental collaborative studies on GBC are necessary to establish evidence-based practice to minimise variation and optimise outcomes.

Temporally Local Tactile Codes Can Be Stored in Working Memory

Tactile exploration often involves sequential touches interspersed with stimulus-free durations (e.g., the time during which the hand moves from one textured surface to the other). Whereas it is obvious that texture-related perceptual variables, irrespective of the encoding strategy, must be stored in memory for comparison, it is rather unclear which of those variables are held in memory. There are two established variables—“intensity” and “frequency”, which are “temporally global” variables because of the long stimulus integration interval required to average the signal or derive spectral components, respectively; on the other hand, a recently established third contender is the “temporally local” variable that codes for kinematic profiles of very short, suprathreshold events in the vibrotactile signal. Here, we present the first psychophysical evidence that temporally local variables can be stored in memory. To that end, we asked participants to detect changes in pulsatile indentation stimuli at their fingertips with and without a gap of 1 s between stimulus presentations. The stimuli either contained global variables alone (change of pulse rate), or a mix of local and global variables (change of pulse shape). We found, first, that humans are much better at detecting a change in stimuli when local variables are available rather than global ones alone—as evident by the fact that 21 compared to only 6 participants out of 25 yielded a valid psychophysical curve, respectively. Second, this observation persists even when there is a gap between the stimuli, implying local variables must be stored in memory. Third, an extensive array of relevant intensity definitions failed to explain participants’ performance in any consistent manner, which implies that perceptual decisions were less likely to be driven by intensity coding. Taken together, our results suggest that humans perform pulsatile change detection utilizing local pulse shape, and to a lesser degree global pulse rate, and that both parameters can be stored in memory.

Local Neuronal Responses to Intracortical Microstimulation in Rats' Barrel Cortex Are Dependent on Behavioral Context

The goal of cortical neuroprosthetics is to imprint sensory information as precisely as possible directly into cortical networks. Sensory processing, however, is dependent on the behavioral context. Therefore, a specific behavioral context may alter stimulation effects and, thus, perception. In this study, we reported how passive vs. active touch, i.e., the presence or absence of whisker movements, affects local field potential (LFP) responses to microstimulation in the barrel cortex in head-fixed behaving rats trained to move their whiskers voluntarily. The LFP responses to single-current pulses consisted of a short negative deflection corresponding to a volley of spike activity followed by a positive deflection lasting ~100 ms, corresponding to long-lasting suppression of spikes. Active touch had a characteristic effect on this response pattern. While the first phase including the negative peak remained stable, the later parts consisting of the positive peak were considerably suppressed. The stable phase varied systematically with the distance of the electrode from the stimulation site, pointing to saturation of neuronal responses to electrical stimulation in an intensity-dependent way. Our results suggest that modulatory effects known from normal sensory processing affect the response to cortical microstimulation as well. The network response to microstimulation is highly amenable to the behavioral state and must be considered for future approaches to imprint sensory signals into cortical circuits with neuroprostheses.

Adaptive Whisking in Mice

Rodents generate rhythmic whisking movements to explore their environment. Whisking trajectories, for one, appear as a fixed pattern of whisk cycles at 5–10 Hz driven by a brain stem central pattern generator. In contrast, whisking behavior is thought to be versatile and adaptable to behavioral goals. To begin to systematically investigate such behavioral adaptation, we established a whisking task, in which mice altered the trajectories of whisking in a goal-oriented fashion to gain rewards. Mice were trained to set the whisker to a defined starting position and generate a protraction movement across a virtual target (no touch-related tactile feedback). By ramping up target distance based on reward history, we observed that mice are able to generate highly specific whisking patterns suited to keep reward probability constant. On a sensorimotor level, the behavioral adaptation was realized by adjusting whisker kinematics: more distant locations were targeted using higher velocities (i.e., pointing to longer force generation), rather than by generating higher acceleration (i.e., pointing to stronger forces). We tested the suitability of the paradigm of tracking subtle alteration in whisking motor commands using small lesions in the rhythmic whisking subfield (RW) of the whisking-related primary motor cortex. Small contralateral RW lesions generated the deterioration of whisking kinematics with a latency of 12 days post-lesion, a change that was readily discriminated from changes in the behavioral adaptation by the paradigm.

Conveyance of texture signals along a rat whisker

Neuronal activities underlying a percept are constrained by the physics of sensory signals. In the tactile sense such constraints are frictional stick-slip events, occurring, amongst other vibrotactile features, when tactile sensors are in contact with objects. We reveal new biomechanical phenomena about the transmission of these microNewton forces at the tip of a rat's whisker, where they occur, to the base where they engage primary afferents. Using high resolution videography and accurate measurement of axial and normal forces at the follicle, we show that the conical and curved rat whisker acts as a sign-converting amplification filter for moment to robustly engage primary afferents. Furthermore, we present a model based on geometrically nonlinear Cosserat rod theory and a friction model that recreates the observed whole-beam whisker dynamics. The model quantifies the relation between kinematics (positions and velocities) and dynamic variables (forces and moments). Thus, only videographic assessment of acceleration is required to estimate forces and moments measured by the primary afferents. Our study highlights how sensory systems deal with complex physical constraints of perceptual targets and sensors.

Risk factors for cystic fibrosis arthropathy: Data from the German cystic fibrosis registry

BACKGROUND

Epidemiology and potential risk factors for cystic fibrosis arthropathy (CFA) were studied in a relevant cystic fibrosis (CF) patient cohort.

METHODS

Cohort study of patients included in the German CF registry in 2016-2017. Descriptive analysis, exploratory tests and multivariable logistic regression were used to assess prevalence of CFA and associated potential risk factors for adult patients with/without chronic Pseudomonas aeruginosa infection.

RESULTS

6069 CF patients aged from 0 to 78 years were analysed. CFA was observed in 4.9% of the patients. Prevalence was significantly higher in adult patients (8.4%) compared to patients <18 years (0.7%; p<0.0001). Logistic regression analyses in adult patients (n=3319) showed that CFA was significantly associated with increasing age (OR=1.04; 95% CI: 1.02-1.05; p<0.0001), female gender (OR=2.10; 95%CI:1.52-2.90; p<0.0001), number of hospitalizations (OR=1.24; 95%CI:1.12-1.36; p<0.0001), chronic P. aeruginosa infection (OR=1.83; 95%CI:1.28-2.61; p=0.0009), CF-related diabetes (OR=1.69; 95%CI:1.23-2.33; p=0.0013), pancreatic insufficiency (OR=2.39; 95%CI:1.28-4.46; p=0.0060) and sinusitis/polyps (OR=1.91; 95%CI:1.39-2.62; p<0.0001). In a subgroup analysis of adults without chronic P. aeruginosa infection (n=1550) CFA was also significantly associated with increasing age, female gender, increasing number of hospitalizations, pancreatic insufficiency as well as sinusitis/polyps; antimycotic treatment associated only in this subgroup while association with CF-related diabetes was not significant.

CONCLUSION

CFA is a frequent and clinically relevant co-morbidity particularly in adult CF patients. CFA is significantly more common in patients with chronic P. aeruginosa colonization but associations with other indicators for a more severe disease course were identified regardless of P. aeruginosa colonization status.

Functional analysis of information rates conveyed by rat whisker-related trigeminal nuclei neurons

The rat whisker system connects the tactile environment with the somatosensory thalamocortical system using only two synaptic stages. Encoding properties of the first stage, the primary afferents with somas in the trigeminal ganglion (TG), has been well studied, whereas much less is known from the second stage, the brainstem trigeminal nuclei (TN). The TN are a computational hub giving rise to parallel ascending tactile pathways and receiving feedback from many brain sites. We asked the question, whether encoding properties of TG neurons are kept by two trigeminal nuclei, the principalis (Pr5) and the spinalis interpolaris (Sp5i), respectively giving rise to two "lemniscal" and two "nonlemniscal" pathways. Single units were recorded in anesthetized rats while a single whisker was deflected on a band-limited white noise trajectory. Using information theoretic methods and spike-triggered mixture models (STM), we found that both nuclei encode the stimulus locally in time, i.e., stimulus features more than 10 ms in the past do not significantly influence spike generation. They further encode stimulus kinematics in multiple, distinct response fields, indicating encoding characteristics beyond previously described directional responses. Compared with TG, Pr5 and Sp5i gave rise to lower spike and information rates, but information rate per spike was on par with TG. Importantly, both brainstem nuclei were found to largely keep encoding properties of primary afferents, i.e. local encoding and kinematic response fields. The preservation of encoding properties in channels assumed to serve different functions seems surprising. We discuss the possibility that it might reflect specific constraints of frictional whisker contact with object surfaces.NEW & NOTEWORTHY We studied two trigeminal nuclei containing the second neuron on the tactile pathway of whisker-related tactile information in rats. We found that the subnuclei, traditionally assumed to give rise to functional tactile channels, nevertheless transfer primary afferent information with quite similar properties in terms of integration time and kinematic profile. We discuss whether such commonality may be due the requirement to adapt to physical constraints of frictional whisker contact.

Metachronous hepatic resection for liver only pancreatic metastases

BACKGROUND

The value of liver resection (LR) for metachronous pancreatic ductal adenocarcinoma (PDAC) metastases remains controversial. However, in light of increasing safety of liver resections, surgery might be a valuable option for metastasized PDAC in selected patients.

METHODS

We performed a retrospective, multicenter study including patients undergoing hepatectomy for metachronous PDAC liver metastases between 2004 and 2015 to analyze postoperative outcome and overall survival. All patients were operated with curative intent. Patients with oligometastatic metachronous liver metastasis with definitive chemotherapy (n = 8) served as controls.

RESULTS

Overall 25 patients in seven centers were included in this study. The median age at the time of LR was 63.8 years (56.9-69.9) and the median number of metastases in the liver was 1 (IQR 1-2). There were eight non-anatomical resections (32%), 15 anatomical minor (60%) and 2 major LR (8%). Postoperative complications occurred in eleven patients (eight Clavien-Dindo grade I complications (32%) and three grade IIIa complications (12%), respectively). The 30-day mortality was 0%. The median length of stay was 8.6 days (IQR 5-11). Median overall survival following LR was 36.8 months compared to 9.2 months in patients with metachronous liver metastasis with chemotherapy (p = 0007).

DISCUSSION

Liver resection for metachronous PDAC metastasis is safe and feasible in selected patients. To address general applicability and to find factors for patient selection, larger trials are urgently warranted.

Propofol Affects Cortico-Hippocampal Interactions via β3 Subunit-Containing GABAA Receptors

BACKGROUND

General anesthetics depress neuronal activity. The depression and uncoupling of cortico-hippocampal activity may contribute to anesthetic-induced amnesia. However, the molecular targets involved in this process are not fully characterized. GABA_A receptors, especially the type with β3 subunits, represent a main molecular target of propofol. We therefore hypothesized that GABA_A receptors with β3 subunits mediate the propofol-induced disturbance of cortico-hippocampal interactions.

METHODS

We used local field potential (LFP) recordings from chronically implanted cortical and hippocampal electrodes in wild-type and β3(N265M) knock-in mice. In the β3(N265M) mice, the action of propofol via β3subunit containing GABA_A receptors is strongly attenuated. The analytical approach contained spectral power, phase locking, and mutual information analyses in the 2-16 Hz range to investigate propofol-induced effects on cortico-hippocampal interactions.

RESULTS

Propofol caused a significant increase in spectral power between 14 and 16 Hz in the cortex and hippocampus of wild-type mice. This increase was absent in the β3(N265M) mutant. Propofol strongly decreased phase locking of 6-12 Hz oscillations in wild-type mice. This decrease was attenuated in the β3(N265M) mutant. Finally, propofol reduced the mutual information between 6-16 Hz in wild-type mice, but only between 6 and 8 Hz in the β3(N265M) mutant.

CONCLUSIONS

GABA_A receptors containing β3 subunits contribute to frequency-specific perturbation of cortico-hippocampal interactions. This likely explains some of the amnestic actions of propofol.

Mapping the Brain-Wide Network Effects by Optogenetic Activation of the Corpus Callosum

Optogenetically driven manipulation of circuit-specific activity enables causality studies, but its global brain-wide effect is rarely reported. Here, we applied simultaneous functional magnetic resonance imaging (fMRI) and calcium recording with optogenetic activation of the corpus callosum (CC) connecting barrel cortices (BC). Robust positive BOLD was detected in the ipsilateral BC due to antidromic activity, spreading to the ipsilateral motor cortex (MC), and posterior thalamus (PO). In the orthodromic target, positive BOLD was reliably evoked by 2 Hz light pulses, whereas 40 Hz light pulses led to reduced calcium, indicative of CC-mediated inhibition. This presumed optogenetic CC-mediated inhibition was further elucidated by pairing light pulses with whisker stimulation at varied interstimulus intervals. Whisker-induced positive BOLD and calcium signals were reduced at intervals of 50/100 ms. The calcium-amplitude-modulation-based correlation with whole-brain fMRI signal revealed that the inhibitory effects spread to contralateral BC, ipsilateral MC, and PO. This work raises the need for fMRI to elucidate the brain-wide network activation in response to optogenetic stimulation.

Awareness and accuracy of height and weight among mothers and their preschool-aged children

OBJECTIVES

A constant challenge in addressing the issue of obesity is the validity and reliability of self-reported measurements to calculate body mass index, that assesses the prevalence of obesity in a population. The objective of this study is to analyze both awareness and accuracy of mothers who are overweight or obese, in reporting their own and their child's height and weight measurements.

STUDY DESIGN

cross-sectional study.

METHODS

In this study, mothers were asked over phone to self-report height and weight for them and their child. This was followed by objective measurement of maternal and child height and weight by study staff in a clinical setting. The descriptive and statistical analysis of the data obtained were carried out using SAS software.

RESULTS

1) The mean weight of mothers who inaccurately self-reported their weight was 9.5 kg greater than the mean weight of those who reported accurately (P < 0.001). (2) Despite being aware of, and reporting their own measurements, 50% (n = 116) of mothers reported not knowing their child's height and 23% (n = 54) of them reported not knowing their child's weight.

CONCLUSION

Strategies to tackle both maternal awareness and accuracy of child's measurements can help with early identification of child's obesity risk and prevention of long-term consequences.

A Tactile Virtual Reality for the Study of Active Somatosensation

Natural exploration of textures involves active sensing, i.e., voluntary movements of tactile sensors (e.g., human fingertips or rodent whiskers) across a target surface. Somatosensory input during moving tactile sensors varies according to both the movement and the surface texture. Combining motor and sensory information, the brain is capable of extracting textural features of the explored surface. Despite the ecological relevance of active sensing, psychophysical studies on active touch are largely missing. One reason for the lack of informative studies investigating active touch is the considerable challenge of assembling an appropriate experimental setup. A possible solution might be in the realm of virtual tactile reality that provides tactile finger stimulation depending on the position of the hand and the simulated texture of a target surface. In addition to rigorous behavioral studies, the investigation of the neuronal mechanisms of active tactile sensing in humans is highly warranted, requiring neurophysiological experiments using electroencephalography (EEG), magnetoencephalography (MEG) and/or functional magnetic resonance imaging (fMRI). However, current neuroimaging techniques impose specific requirements on the tactile stimulus delivery equipment in terms of compatibility with the neurophysiological methods being used. Here, we present a user-friendly, MEG compatible, tactile virtual reality simulator. The simulator consists of a piezo-electric tactile stimulator capable of independently protruding 16 plastic pistons of 1 mm diameter arranged in a 4 × 4 matrix. The stimulator delivers a spatial pattern of tactile stimuli to the tip of a finger depending on the position of the finger moving across a 2-dimensional plane. In order to demonstrate the functionality of the tactile virtual reality, we determined participants’ detection thresholds in active and passive touch conditions. Thresholds in both conditions were higher than reported in the literature. It could well be that the processing of the piston-related stimulation was masked by the sensory input generated by placing the finger on the scanning probe. More so, the thresholds for both the active and passive tasks did not differ significantly. In further studies, the noise introduced by the stimulator in neuromagnetic recordings was quantified and somatosensory evoked fields for active and passive touch were recorded. Due to the compatibility of the stimulator with neuroimaging techniques such as MEG, and based on the feasibility to record somatosensory-related neuromagnetic brain activity the apparatus has immense potential for the exploration of the neural underpinnings of active tactile perception.

Effects of Omega-3 Fatty Acids on Resting Cerebral Perfusion in Patients with Mild Cognitive Impairment: A Randomized Controlled Trial

Alteration of cerebral perfusion can be considered as a possible therapeutic target in mild cognitive impairment. This randomized, placebo-controlled, double-blind proof-of-concept study assessed effects of omega-3 fatty acids on cerebral perfusion in patients with mild cognitive impairment. In thirteen patients (omega:n=5; placebo:n=8) cerebral perfusion was measured before and after 26-weeks intervention within posterior cortical regions using magnetic resonance imaging. There was a medium effect of intervention on cerebral blood flow (η2=0.122) and blood volume (η2=0.098). The omega group showed an increase in blood flow (mean difference: 0.02 [corresponds to 26.1%], 95% confidence interval:0.00-0.05) and blood volume (mean difference: 0.08 [corresponds to 18.5%], 95% confidence interval:0.01-0.15), which was not observed in the placebo group. These preliminary findings suggest that omega-3 fatty acids supplementation may improve perfusion in cerebral regions typically affected in mild cognitive impairment.Regulation of perfusion may help to maintain brain structure and function and potentially delay conversion to dementia.

Global Tactile Coding in Rat Barrel Cortex in the Absence of Local Cues

Although whisker-related perception is based predominantly on local, near-instantaneous coding, global, intensive coding, which integrates the vibrotactile signal over time, has also been shown to play a role given appropriate behavioral conditions. Here, we study global coding in isolation by studying head-fixed rats that identified pulsatile stimuli differing in pulse frequency but not in pulse waveforms, thus abolishing perception based on local coding. We quantified time locking and spike counts as likely variables underpinning the 2 coding schemes. Both neurometric variables contained substantial stimulus information, carried even by spikes of single barrel cortex neurons. To elucidate which type of information is actually used by the rats, we systematically compared psychometric with neurometric sensitivity based on the 2 coding schemes. Neurometric performance was calculated by using a population-encoding model incorporating the properties of our recorded neuron sample. We found that sensitivity calculated from spike counts sampled over long periods (>1 s) matched the performance of rats better than the one carried by spikes time-locked to the stimulus. We conclude that spike counts are more relevant to tactile perception when instantaneous kinematic parameters are not available.

[Cystic fibrosis : A new disease pattern in adult medicine]

Cystic fibrosis (CF) is an inherited incurable multi-organ disease. Improvement in treatment approaches over the last 20 years have led to an increased life expectancy where the number of adult patients has doubled and will continue to increase exponentially. Due to the use of new substances which modulate the basic defect, a substantial improvement in the prognosis can be assumed but the existing healthcare structures in Germany do not meet these rising needs. With more than 50% of patients being adults, there are only very few internal medicine centers available. Only approximately one third of the patients are treated in adult health centers. Adolescence in particular is a very vulnerable phase of the disease, the risk of comorbidities is increased and adherence to the very laborious treatment recommendations is as a rule low. While in many other countries transition programs have been evaluated and implemented for more than 20 years, in Germany there have only been rudimentary approaches to transition. Meanwhile investigations are available on the perceptions of adolescents with respect to coping with the disease and their treatment needs, including the perception of the time when the transition process should begin. Successful transition seems to be performed best in combined pediatric and adult centers, with the back-up of an experienced multidisciplinary team of healthcare providers.

Biomechanical Texture Coding in Rat Whiskers

Classically, texture discrimination has been thought to be based on ‘global’ codes, i.e. frequency (signal analysis based on Fourier analysis) or intensity (signal analysis based on averaging), which both rely on integration of the vibrotactile signal across time and/or space. Recently, a novel ‘local’ coding scheme based on the waveform of frictional movements, discrete short lasting kinematic events (i.e. stick-slip movements called slips) has been formulated. We performed biomechanical measurements of relative movements of a rat vibrissa across sandpapers of different roughness. We find that the classic global codes convey some information about texture identity, but are consistently outperformed by the slip-based local code. Moreover, the slip code also surpasses the global ones in coding for active scanning parameters. This is remarkable as it suggests that the slip code would explicitly allow the whisking rat to optimize perception by selecting goal-specific scanning strategies.

Mesh-augmented versus direct abdominal closure in patients undergoing open abdomen treatment

Background

Open abdomen (OA) may be required in patients with abdominal trauma, sepsis or compartment syndrome. Vacuum-assisted wound closure and mesh-mediated fascial traction (VAWCM) is a widely used approach for temporary abdominal closure to close the abdominal wall. However, this method is associated with a high incidence of re-operations in short term and late sequelae such as incisional hernia. The current study aims to compare the results of surgical strategies of OA with versus without permanent mesh augmentation.

Methods

Patients with OA treatment undergoing vacuum-assisted wound closure and an intraperitoneal onlay mesh (VAC-IPOM) implantation were compared to VAWCM with direct fascial closure which represents the current standard of care. Outcomes of patients from two tertiary referral centers that performed the different strategies for abdominal closure after OA treatment were compared in univariate and multivariate regression analysis.

Results

A total of 139 patients were included in the study. Of these, 50 (36.0%) patients underwent VAC-IPOM and 89 (64.0%) patients VAWCM. VAC-IPOM was associated with reduced re-operations (adjusted incidence risk ratio 0.48 per 10-person days; CI 95% = 0.39–0.58, p < 0.001), reduced duration of stay on intensive care unit (ICU) [adjusted hazard ratio (aHR) 0.53; CI 95% = 0.36–0.79, p = 0.002] and reduced hospital stay (aHR 0.61; CI 95% = 0.040–0.94; p = 0.024). In-hospital mortality [22.5 vs 18.0%, risk difference − 4.5; confidence interval (CI) 95% = − 18.2 to 9.3; p = 0.665] and the incidence of intestinal fistula (18.0 vs 22.0%, risk difference 4.0; CI 95% = −10.0 to 18.0; p = 0.656) did not differ between the two groups. In Kaplan–Meier analysis, hernia-free survival was significantly increased after VAC-IPOM (p = 0.041).

Conclusions

In patients undergoing OA treatment, intraperitoneal mesh augmentation is associated with a significantly decreased number of re-operations, duration of hospital and ICU stay and incidence of incisional hernias when compared to VAWCM.

Electronic supplementary material

The online version of this article (10.1007/s10029-018-1798-9) contains supplementary material, which is available to authorized users.

Primary Tactile Thalamus Spiking Reflects Cognitive Signals

Little is known about whether information transfer at primary sensory thalamic nuclei is modified by behavioral context. Here we studied the influence of previous decisions/rewards on current choices and preceding spike responses of ventroposterior medial thalamus (VPm; the primary sensory thalamus in the rat whisker-related tactile system). We trained head-fixed rats to detect a ramp-like deflection of one whisker interspersed within ongoing white noise stimulation. Using generative modeling of behavior, we identify two task-related variables that are predictive of actual decisions. The first reflects task engagement on a local scale ("trial history": defined as the decisions and outcomes of a small number of past trials), whereas the other captures behavioral dynamics on a global scale ("satiation": slow dynamics of the response pattern along an entire session). Although satiation brought about a slow drift from Go to NoGo decisions during the session, trial history was related to local (trial-by-trial) patterning of Go and NoGo decisions. A second model that related the same predictors first to VPm spike responses, and from there to decisions, indicated that spiking, in contrast to behavior, is sensitive to trial history but relatively insensitive to satiation. Trial history influences VPm spike rates and regularity such that a history of Go decisions would predict fewer noise-driven spikes (but more regular ones), and more ramp-driven spikes. Neuronal activity in VPm, thus, is sensitive to local behavioral history, and may play an important role in higher-order cognitive signaling.SIGNIFICANCE STATEMENT It is an important question for perceptual and brain functions to find out whether cognitive signals modulate the sensory signal stream and if so, where in the brain this happens. This study provides evidence that decision and reward history can already be reflected in the ascending sensory pathway, on the level of first-order sensory thalamus. Cognitive signals are relayed very selectively such that only local trial history (spanning a few trials) but not global history (spanning an entire session) are reflected.

[CF Lung Disease - a German S3 Guideline: Module 2: Diagnostics and Treatment in Chronic Infection with Pseudomonas aeruginosa]

Cystic Fibrosis (CF) is the most common autosomal-recessive genetic disease affecting approximately 8000 people in Germany. The disease is caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene leading to dysfunction of CFTR, a transmembrane chloride channel. This defect causes insufficient hydration of the epithelial lining fluid which leads to chronic inflammation of the airways. Recurrent infections of the airways as well as pulmonary exacerbations aggravate chronic inflammation, lead to pulmonary fibrosis and tissue destruction up to global respiratory insufficiency, which is responsible for the mortality in over 90 % of patients. The main aim of pulmonary treatment in CF is to reduce pulmonary inflammation and chronic infection. Pseudomonas aeruginosa (Pa) is the most relevant pathogen in the course of CF lung disease. Colonization and chronic infection are leading to additional loss of pulmonary function. There are many possibilities to treat Pa-infection. This is a S3-clinical guideline which implements a definition for chronic Pa-infection and demonstrates evidence-based diagnostic methods and medical treatment for Pa-infection in order to give guidance for individual treatment options.