Long-Term Effects of an Oligoantigenic Diet in Children with Attention-Deficit/Hyperactivity Disorder (ADHD) on Core Symptomatology.

In the early 1920s, it was discovered that nutrition is associated with what is known today as Attention-Deficit/Hyperactivity Disorder (ADHD) and that certain foods can worsen the symptoms. In previous studies, approximately 60% of the participants experience at least a 40% reduction in ADHD symptoms after an oligoantigenic diet (OD). The purpose of this study was to evaluate ADHD symptoms in children approximately 3.5 years after completing a 4-week oligoantigenic diet. Among 28 participants who completed the 4-week diet, 21 were re-assessed for this study after 3.5 years. The severity of ADHD symptoms was assessed with the ADHD-Rating-Scale-IV (ARS). Of 21 participants, 14 fulfilled the responder criterion, whereas 7 did not. At follow-up, 28% of the participants were taking medication. The mean ARS total score improved significantly from T1: M = 29.62 (SD = 9.80) to T2: M = 15.86 (SD = 8.56) between the time points before and after the diet (d = -1.91). There was also a lower ARS total score at the follow-up T5: M = 16.00 (SD = 10.52) compared to before the diet (d = -1.17). This study shows that individually adjusted nutrition significantly improved the ADHD symptomatology of the participants long-term. This suggests that an oligoantigenic diet with subsequent individual nutritional recommendations could become an additional treatment option for children with ADHD.

Mass Photometry of Membrane Proteins.

Integral membrane proteins (IMPs) are biologically highly significant but challenging to study because they require maintaining a cellular lipid-like environment. Here, we explore the application of mass photometry (MP) to IMPs and membrane-mimetic systems at the single-particle level. We apply MP to amphipathic vehicles, such as detergents and amphipols, as well as to lipid and native nanodiscs, characterizing the particle size, sample purity, and heterogeneity. Using methods established for cryogenic electron microscopy, we eliminate detergent background, enabling high-resolution studies of membrane-protein structure and interactions. We find evidence that, when extracted from native membranes using native styrene-maleic acid nanodiscs, the potassium channel KcsA is present as a dimer of tetramers-in contrast to results obtained using detergent purification. Finally, using lipid nanodiscs, we show that MP can help distinguish between functional and non-functional nanodisc assemblies, as well as determine the critical factors for lipid nanodisc formation.

Image analysis in posttreatment non-small cell lung cancer surveillance: specialists' interpretations reviewed by the thoracic multidisciplinary tumor board.

BACKGROUND: Data show that the initial specialist's image interpretation and final multidisciplinary tumor board (MTB) assessment can vary substantially in the pretherapeutic cancer setting. The aim of this post hoc analysis was to investigate the concordance of the specialist's and MTB's image interpretations in patients undergoing systematic posttreatment lung cancer image surveillance. METHODS: In the initial prospective study, lung cancer patients who had received curative-intent treatment were randomly assigned to undergo either contrast-enhanced computed tomography (CE-CT) or integrated 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT). Imaging was performed every 6 months for 2 years, and all imaging studies were finally assessed by our MTB. This post hoc analysis assessed differences between the initial specialist's image interpretation and the final MTB's image interpretation. RESULTS: In 89 patients, 266 imaging studies (129 PET-CT, 137 CE-CT) were analyzed. In 87.2% (88.4, 86.1%) of the studies, complete concordance was found. Out of the 12.8% (11.6, 13.9%) with discordant results, 7.5% (6.9, 8.0%) had implications for alterations in patient management (major disagreements).Twenty major disagreements were detected in 17 study patients. Retrospectively, in eight out of these 17 (47%) patients, in contrast to the MTB's view, the specialist's interpretation was more appropriate, whereas in nine out of 17 patients (53%), the MTB's interpretation was more accurate. CONCLUSIONS: In an experienced MTB, the agreement between imaging specialists and the rest of the MTB with regard to the interpretation of images is high in a setting of posttreatment lung cancer image surveillance. It seems that in cases of disagreements, the rates of more accurate interpretation are well balanced between imaging specialists and the MTB. TRIAL REGISTRATION: ISRCTN16281786, Date 23. February 2017.

Nuclear Magnetic Resonance Solution Structure and Functional Behavior of the Human Proton Channel.

The human voltage-gated proton channel [Hv1(1) or VSDO(2)] plays an important role in the human innate immune system. Its structure differs considerably from those of other cation channels. It is built solely of a voltage-sensing domain and thus lacks the central pore domain, which is essential for other cation channels. Here, we determined the solution structure of an N- and C-terminally truncated human Hv1 (Δ-Hv1) in the resting state by nuclear magnetic resonance (NMR) spectroscopy. Δ-Hv1 comprises the typical voltage-sensing antiparallel four-helix bundle (S1-S4) preceded by an amphipathic helix (S0). The solution structure corresponds to an intermediate state between resting and activated forms of voltage-sensing domains. Furthermore, Zn2+-induced closing of proton channel Δ-Hv1 was studied with two-dimensional NMR spectroscopy, which showed that characteristic large scale dynamics of open Δ-Hv1 are absent in the closed state of the channel. Additionally, pH titration studies demonstrated that a higher H+ concentration is required for the protonation of side chains in the Zn2+-induced closed state than in the open state. These observations demonstrate both structural and dynamical changes involved in the process of voltage gating of the Hv1 channel and, in the future, may help to explain the unique properties of unidirectional conductance and the exceptional ion selectivity of the channel.

Serious adverse events in patients with target-oriented blood pressure management: a systematic review.

: On the basis of the benefits of antihypertensive treatment, progressively intensive treatment is advocated. However, it remains controversial whether intensive blood pressure control might increase the frequency of serious adverse events (SAEs) compared with moderate control. This review assessed the occurrence of SAEs in blood pressure treatment with predefined blood pressure targets. Seven original studies and eight post hoc analyses (derived from two original studies) met the inclusion criteria. Compared with moderate blood pressure treatment, intensive treatment was associated with a significant increase in treatment-related SAEs (Sign-test: P = 0.0002, Wilcoxon signed-rank test: P = 0.001). However, comparability between studies was limited, due to unclear determinations about the treatment-relatedness of adverse events, missing definitions of SAEs and variations in recording methods. Thus, a meta-analysis was not justified. The definitions of serious adverse events and methods of recording and reporting need to be improved and standardized to facilitate the comparison of results.

Probing Ion Binding in the Selectivity Filter of the KcsA Potassium Channel.

In potassium (K+) channels, permeation, selectivity, and gating at the selectivity filter are all governed by the thermodynamics and kinetics of the ion-protein interactions. Specific contacts between the carbonyl groups from the Thr-Val-Gly-Tyr-Gly signature filter sequence and the permeant ions generate four equidistant K+ binding sites, thereby defining the high ion selectivity and controlling the transport rate of K+ channels. Here, we used 15N-labeled ammonium (15NH4+) as a proxy for K+ to study ion interaction with the selectivity filter of the prototypical full-length K+ channel KcsA by solution state NMR spectroscopy in order to obtain detailed insights into the physicochemical basis of K+ gating. We found that in the closed inactive state of KcsA (at pH 7) four K+ binding sites are occupied over a wide range of 15NH4+ concentrations, while in intermediate closed-open conformations (at pH ∼6) the number and occupancy of K+ binding sites are reduced to two. However, in the presence of the scorpion toxin agitoxin II a total loss of 15NH4+ binding is observed. 15NH4+ titration studies allowed us to determine the dissociation constants of the four binding sites with values around 10 mM in the closed state of KcsA. Moreover, kinetic NMR experiments measured in the steady state equilibrium detected an off- and on-rate for 15NH4+ of ca. 102 s-1 and 103 s-1 between KcsA-bound 15NH4+ and the bulk. These findings reveal both the thermodynamics and kinetics of the ion binding sites and thus contribute to our understanding of the action of K+ channels.

Comparing Two Imaging Methods for Follow-Up of Lung Cancer Treatment: A Randomized Pilot Study.

BACKGROUND: Scientific data on the image modality to be used in postcurative treatment surveillance of non-small cell lung cancer patients are scarce. This prospective randomized pilot trial compared the performance of integrated 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) and contrast-enhanced computed tomography (CE-CT). METHODS: After termination of curative-intent treatment, patients were randomly assigned to the PET-CT or the CE-CT group. Imaging was performed every 6 months for 2 years. If suspicious radiologic findings were detected or patients became symptomatic, a diagnostic workup was initiated. Sensitivity, specificity, and positive predictive value for detecting cancer recurrence were calculated for both imaging procedures. RESULTS: The study enrolled 96 patients. In 14 of 50 patients (28%) in the PET-CT group and in 14 of 46 patients (30%) in the CE-CT group, a suspicious radiologic finding was confirmed as cancer recurrence after diagnostic workup. False-positive findings were detected in 11 patients (22%) of the PET-CT group and in 8 patients (17%) of the CE-CT group. The sensitivity, specificity, and positive predictive value for detecting cancer recurrence (95% confidence interval) were 0.88 (0.62 to 0.98), 0.62 (0.42 to 0.79), and 0.56 (0.35 to 0.76) for PET-CT and 0.93 (0.68 to 1.00), 0.72 (0.53 to 0.87), and 0.64 (0.41to 0.83) for CE-CT, respectively. CONCLUSIONS: The results of our study suggest that PET-CT is not superior to CE-CT in detecting cancer recurrence during 2 years after curative-intent treatment of non-small cell lung cancer.

Lipid- and Cholesterol-Mediated Time-Scale-Specific Modulation of the Outer Membrane Protein X Dynamics in Lipid Bilayers.

Membrane protein function fundamentally depends on lipid-bilayer fluidity and the composition of the biological membrane. Although dynamic interdependencies between membrane proteins and the surrounding lipids are suspected, a detailed description is still missing. To uncover lipid-modulated membrane protein backbone dynamics, time-scale-specific NMR relaxation experiments with residue-resolution were recorded. The data revealed that lipid order, modified either biochemically or biophysically, changes the dynamics of the immersed membrane protein in a specific and time-scale-dependent manner. A temperature-dependent dynamics analysis furthermore suggests a direct coupling between lipid and protein dynamics in the picosecond-nanosecond, microsecond, and millisecond time scales, caused by the lipid's trans-gauche isomerization, the segmental and rotational motion of lipids, and the fluidity of the lipid phase, respectively. These observations provide evidence of a direct modulatory capability of the membrane to regulate protein function through lipid dynamics ranging from picoseconds to milliseconds.

15N transverse relaxation measurements for the characterization of µs-ms dynamics are deteriorated by the deuterium isotope effect on 15N resulting from solvent exchange.

15N R2 relaxation measurements are key for the elucidation of the dynamics of both folded and intrinsically disordered proteins (IDPs). Here we show, on the example of the intrinsically disordered protein α-synuclein and the folded domain PDZ2, that at physiological pH and near physiological temperatures amide-water exchange can severely skew Hahn-echo based 15N R2 relaxation measurements as well as low frequency data points in CPMG relaxation dispersion experiments. The nature thereof is the solvent exchange with deuterium in the sample buffer, which modulates the 15N chemical shift tensor via the deuterium isotope effect, adding to the apparent relaxation decay which leads to systematic errors in the relaxation data. This results in an artificial increase of the measured apparent 15N R2 rate constants-which should not be mistaken with protein inherent chemical exchange contributions, Rex, to 15N R2. For measurements of 15N R2 rate constants of IDPs and folded proteins at physiological temperatures and pH, we recommend therefore the use of a very low D2O molar fraction in the sample buffer, as low as 1%, or the use of an external D2O reference along with a modified 15N R2 Hahn-echo based experiment. This combination allows for the measurement of Rex contributions to 15N R2 originating from conformational exchange in a time window from µs to ms.

Quantitative mass imaging of single biological macromolecules.

The cellular processes underpinning life are orchestrated by proteins and their interactions. The associated structural and dynamic heterogeneity, despite being key to function, poses a fundamental challenge to existing analytical and structural methodologies. We used interferometric scattering microscopy to quantify the mass of single biomolecules in solution with 2% sequence mass accuracy, up to 19-kilodalton resolution, and 1-kilodalton precision. We resolved oligomeric distributions at high dynamic range, detected small-molecule binding, and mass-imaged proteins with associated lipids and sugars. These capabilities enabled us to characterize the molecular dynamics of processes as diverse as glycoprotein cross-linking, amyloidogenic protein aggregation, and actin polymerization. Interferometric scattering mass spectrometry allows spatiotemporally resolved measurement of a broad range of biomolecular interactions, one molecule at a time.

Proton-Detected NMR Spectroscopy of Nanodisc-Embedded Membrane Proteins: MAS Solid-State vs Solution-State Methods.

The structural and dynamical characterization of membrane proteins in a lipid bilayer at physiological pH and temperature and free of crystal constraints is crucial for the elucidation of a structure/dynamics-activity relationship. Toward this aim, we explore here the properties of the outer-membrane protein OmpX embedded in lipid bilayer nanodiscs using proton-detected magic angle spinning (MAS) solid-state NMR at 60 and 110 kHz. [1H,15N]-correlation spectra overlay well with the corresponding solution-state NMR spectra. Line widths as well as line intensities in solid and solution both depend critically on the sample temperature and, in particular, on the crossing of the lipid phase transition temperature. MAS (110 kHz) experiments yield well-resolved NMR spectra also for fully protonated OmpX and both below and above the lipid phase transition temperature.

Lipid Internal Dynamics Probed in Nanodiscs.

Nanodiscs offer a very promising tool to incorporate membrane proteins into native-like lipid bilayers and an alternative to liposomes to maintain protein functions and protein-lipid interactions in a soluble nanoscale object. The activity of the incorporated membrane protein appears to be correlated to its dynamics in the lipid bilayer and by protein-lipid interactions. These two parameters depend on the lipid internal dynamics surrounded by the lipid-encircling discoidal scaffold protein that might differ from more unrestricted lipid bilayers observed in vesicles or cellular extracts. A solid-state NMR spectroscopy investigation of lipid internal dynamics and thermotropism in nanodiscs is reported. The gel-to-fluid phase transition is almost abolished for nanodiscs, which maintain lipid fluid properties for a large temperature range. The addition of cholesterol allows fine-tuning of the internal bilayer dynamics by increasing chain ordering. Increased site-specific order parameters along the acyl chain reflect a higher internal ordering in nanodiscs compared with liposomes at room temperature; this is induced by the scaffold protein, which restricts lipid diffusion in the nanodisc area.

Micelles, Bicelles, and Nanodiscs: Comparing the Impact of Membrane Mimetics on Membrane Protein Backbone Dynamics.

Detergents are often used to investigate the structure and dynamics of membrane proteins. Whereas the structural integrity seems to be preserved in detergents for many membrane proteins, their functional activity is frequently compromised, but can be restored in a lipid environment. Herein we show with per-residue resolution that while OmpX forms a stable ß-barrel in DPC detergent micelles, DHPC/DMPC bicelles, and DMPC nanodiscs, the pico- to nanosecond and micro- to millisecond motions differ substantially between the detergent and lipid environment. In particular for the ß-strands, there is pronounced dynamic variability in the lipid environment, which appears to be suppressed in micelles. This unexpected complex and membrane-mimetic-dependent dynamic behavior indicates that the frequent loss of membrane protein activity in detergents might be related to reduced internal dynamics and that membrane protein activity correlates with lipid flexibility.

Effect of viscogens on the kinetic response of a photoperturbed allosteric protein.

By covalently binding a photoswitchable linker across the binding groove of the PDZ2 domain, a small conformational change can be photo-initiated that mimics the allosteric transition of the protein. The response of its binding groove is investigated with the help of ultrafast pump-probe IR spectroscopy from picoseconds to tens of microseconds. The temperature dependence of that response is compatible with diffusive dynamics on a rugged energy landscape without any prominent energy barrier. Furthermore, the dependence of the kinetics on the concentration of certain viscogens, sucrose, and glycerol, has been investigated. A pronounced viscosity dependence is observed that can be best fit by a power law, i.e., a fractional viscosity dependence. The change of kinetics when comparing sucrose with glycerol as viscogen, however, provides strong evidence that direct interactions of the viscogen molecule with the protein do play a role as well. This conclusion is supported by accompanying molecular dynamics simulations.

Diastolic aorto-right-atrial fistulation in aortic and tricuspid valve endocarditis.

Background Aorto-right-atrial fistula in native valve endocarditis is very rare. Case Description A 45-year-old woman was referred with an endocarditis with a perforated right cusp of the aortic valve with at least moderate insufficiency and an affected tricuspid annulus with vegetations. In addition to this, an aorto-cavitary fistula from the aortic sinus to the right atrium with a holodiastolic left-right shunt had been detected. Streptococci viridans were found as underlying pathogen. Complete replacement of the aortic root and resection of the fistula were performed with good result. Conclusion Endocarditis with fistula formation is rare and has to be treated aggressively.