Proton-decoupled deuterium NMR study of an asymmetric liquid crystal dimer having two nematic phases.

Proton-decoupled deuterium NMR spectra were obtained for an asymmetric liquid crystal dimer 1-(4-cyanobiphenyl-4'-yloxy)-6-(4-cyanobiphenyl-4'-yl)hexane (CB6OCB) containing a single -CD_{2}- group. The sample has two nematic liquid crystal phases: a twist-bend nematic, N_{TB}, at the lowest temperature followed by a uniaxial nematic, N_{U}, on increasing the temperature. Proton decoupling reduces the linewidths of the peaks in the deuterium spectrum from kHz to ∼100Hz, enabling quadrupolar splittings, Δν, to be obtained with enhanced precision as well as the dipolar coupling between deuterium nuclei within the CD_{2} group, hence enhancing the information content.

Perifocal Edema in Patients with Meningioma is Associated with Impaired Whole-Brain Connectivity as Detected by Resting-State fMRI.

BACKGROUND AND PURPOSE: Meningiomas are intracranial tumors that usually carry a benign prognosis. Some meningiomas cause perifocal edema. Resting-state fMRI can be used to assess whole-brain functional connectivity, which can serve as a marker for disease severity. Here, we investigated whether the presence of perifocal edema in preoperative patients with meningiomas leads to impaired functional connectivity and if these changes are associated with cognitive function. MATERIALS AND METHODS: Patients with suspected meningiomas were prospectively included, and resting-state fMRI scans were obtained. Impairment of functional connectivity was quantified on a whole-brain level using our recently published resting-state fMRI-based marker, called the dysconnectivity index. Using uni- and multivariate regression models, we investigated the association of the dysconnectivity index with edema and tumor volume as well as cognitive test scores. RESULTS: Twenty-nine patients were included. In a multivariate regression analysis, there was a highly significant association of dysconnectivity index values and edema volume in the total sample and in a subsample of 14 patients with edema, when accounting for potential confounders like age and temporal SNR. There was no statistically significant association with tumor volume. Better neurocognitive performance was strongly associated with lower dysconnectivity index values. CONCLUSIONS: Resting-state fMRI showed a significant association between impaired functional connectivity and perifocal edema, but not tumor volume, in patients with meningiomas. We demonstrated that better neurocognitive function was associated with less impairment of functional connectivity. This result shows that our resting-state fMRI marker indicates a detrimental influence of peritumoral brain edema on global functional connectivity in patients with meningiomas.

A highly versatile biopolymer-based platform for the maturation of human pluripotent stem cell-derived cardiomyocytes enables functional analysis in vitro and 3D printing of heart patches.

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) represent a valuable tool for in vitro modeling of the cardiac niche and possess great potential in tissue engineering applications. However, conventional polystyrene-based cell culture substrates have adverse effects on cardiomyocytes in vitro due to the stress applied by a stiff substrate on contractile cells. Ultra-high viscosity alginates offer a unique versatility as tunable substrates for cardiac cell cultures due to their biocompatibility, flexible biofunctionalization, and stability. In this work, we analyzed the effect of alginate substrates on hPSC-CM maturity and functionality. Alginate substrates in high-throughput compatible culture formats fostered a more mature gene expression and enabled the simultaneous assessment of chronotropic and inotropic effects upon beta-adrenergic stimulation. Furthermore, we produced 3D-printed alginate scaffolds with differing mechanical properties and plated hPSC-CMs on the surface of these to create Heart Patches for tissue engineering applications. These exhibited synchronous macro-contractions in concert with more mature gene expression patterns and extensive intracellular alignment of sarcomeric structures. In conclusion, the combination of biofunctionalized alginates and human cardiomyocytes represents a valuable tool for both in vitro modeling and regenerative medicine, due to its beneficial effects on cardiomyocyte physiology, the possibility to analyze cardiac contractility, and its applicability as Heart Patches.

Clinical onset of CNS demyelinating disease after COVID-19 vaccination: denovo disease?

BACKGROUND: Clinical onset of multiple sclerosis (MSpostvacc) and myelin-oligodendrocyte-glycoprotein-antibody-associated disease (MOGADpostvacc) has been reported in association with SARS-CoV-2-vaccination. There is uncertainty as to whether this is causality (denovo disease) or temporal coincidence (manifestation of a preexisting, subclinical neuroinflammation). OBJECTIVES: Comparing the clinical characteristics of MSpostvacc-patients versus patients with MS (PwMS) whose clinical onset occurred independently of vaccination (MSreference). METHODS: Consecutive patients with clinical onset ≤30 days after SARS-CoV-2-vaccination were included. Clinical data, cerebrospinal fluid (CSF) parameters and magnetic resonance imaging (MRI) as well as optical coherence tomography (OCT) data were compared to an age- and sex-matched MSreference-cohort. RESULTS: We identified 5 MSpostvacc and 1 MOGADpostvacc patients who developed their clinical onset ≤ 30 days after SARS-CoV-2-vaccination. Clinical characteristics, CSF, MRI and OCT parameters from MSpostvacc patients were comparable to the MSreference cohort and showed evidence of preexisting subclinical CNS disease. The single case with MOGADpostvacc clearly differed from PwMS in higher CSF cell counts, remission of MRI lesions during follow-up, and absence of oligoclonal bands. CONCLUSIONS: Our case series indicates that MSpostvacc patients showed a rather typical initial manifestation in temporal association with SARS-CoV-2-vaccination and harbored preexisting subclinical neuroinflammation. This argues against the denovo development of MS in this cohort.

Distinct serum metabolomic signatures of multiparous and primiparous dairy cows switched from a moderate to high-grain diet during early lactation.

INTRODUCTION: Feeding of high-grain diets is common in cows during early lactation, but increases the odds of metabolic derailments, which can likely be detected as undesirable shifts in the serum metabolome signature. OBJECTIVES: The present study aimed to identify the metabolic signatures of the serum metabolome of early lactation dairy cows switched from a moderate to a high-grain diet. METHODS: Targeted ESI-LC-MS/MS-based metabolomics was used to characterize metabolic alterations in the serum of early lactation multiparous (MP, n = 16) and primiparous (PP, n = 8) Simmental cows, according to parity and feeding phase. Data were analysed using different data mining approaches. RESULTS: Carnitine, acetylcarnitine, propionoylcarnitine, amino acid related compounds cis-4-hydroxyproline, trans-4-hydroxyproline, proline betaine, lysophosphatidylcholine PC a C16:1 and phosphatidylcholine PC ae C36:0 were identified as the key metabolites distinguishing MP from PP cows. A different serum metabolite composition during moderate and high-grain diet was also evident. Notably, cows fed high grain diet had higher serum concentrations of primary bile acids and triglycerides, but lower levels of conjugated bile acids and carboxylic acids during the first week in grain. Amino acids valine, cystine and taurine together with lysophosphatidylcholine PC a C26:0 and several phosphatidylcholines were classified as important features for cluster separation. CONCLUSIONS: Our study greatly expands earlier observations on dietary effects on serum metabolome composition of cows. The altered metabolomic fingerprints clearly distinguishable by diet and cow parity hold potential to be used as early diagnostic tools for cows experiencing grain-induced metabolic disturbances.

Detoxifying deoxynivalenol (DON)-contaminated feedstuff: consequences of sodium sulphite (SoS) treatment on performance and blood parameters in fattening pigs.

A 10-week feeding experiment was carried out examining the effects of deoxynivalenol (DON)-contaminated maize treated with different sodium sulphite (SoS) concentrations on performance, health and DON-plasma concentrations in fattening pigs. Two maize batches were used: background-contaminated (CON, 0.73 mg/kg maize) and Fusarium-toxin contaminated (DON, 44.45 mg/kg maize) maize. Both were wet preserved at 20% moisture content, with one of three (0.0, 2.5, 5.0 g/kg maize) sodium sulphite concentrations and propionic acid (15%). Each maize batch was then mixed into a barley-wheat-based diet at a proportion of 10%, resulting in the following 6 feeding groups: CON- (CON + 0.0 g SoS/kg maize), CON2.5 (CON + 2.5 g SoS/kg maize), CON5.0 (CON + 5.0 g SoS/kg maize), DON- (DON + 0.0 g SoS/kg maize), DON2.5 (DON + 2.5 g SoS/kg maize) and DON5.0 (DON + 5.0 g SoS/kg maize). Dietary DON concentration was reduced by ~ 36% in group DON2.5 and ~ 63% in group DON5.0. There was no impact on ZEN concentration in the diets due to SoS treatment. Pigs receiving diet DON- showed markedly lower feed intake (FI) compared to those fed the control diets. With SoS-treatment of maize, FI of pigs fed the DON diet (DON5.0: 3.35 kg/d) were comparable to that control (CON-: 3.30 kg/day), and these effects were also reflected in live weight gain. There were some effects of SoS, DON or their interaction on serum urea, cholesterol and albumin, but always within the physiological range and thus likely negligible. SoS wet preservation of Fusarium-toxin contaminated maize successfully detoxified DON to its innocuous sulfonates, thus restoring impaired performance in fatteners.

Determination of aflatoxin biomarkers in excreta and ileal content of chickens.

Aflatoxins are carcinogenic secondary metabolites frequently detected in food and feed stuff based on maize and other crops susceptible to infection with the fungal pathogen Aspergillus flavus. We investigated the metabolization of aflatoxins in chickens by analyzing excreta and ileal content and developed and validated a biomarker method for detection of aflatoxins and their metabolites in these matrices. Analysis of ileal content served to distinguish between urinary and fecal excretion combined in the excreta samples. During a 3-wk animal trial, one hundred sixty-eight 1-day-old chicks were randomly allocated to 24 pens with 7 chicks per pen and subjected to different feed regimens with: A) toxin-free feed, B) feed supplemented with 18 ng of total aflatoxins/g, and C) feed supplemented with 515 ng of total aflatoxins/g. Chicken excreta and ileal content were sampled after 7, 14, and 21 D. An analytical method based on liquid chromatography coupled to tandem mass spectrometry was validated for the determination of aflatoxin B1, B2, G1, G2, M1, P1, Q1, and aflatoxin B1-N7-guanine (AFB1-N7-Gua) in chicken's samples. Comparing chicken excreta, which contain urine and feces, to ileal content, which contains no urine, we explored the secretion pathway of aflatoxin metabolites. The AFB1-N7-Gua was only detected in excreta, whereas aflatoxin M1 (AFM1) was detected both in ileal content and excreta. Aflatoxin M1 was detected in excreta in concentrations 5 times higher than in ileal content, suggesting primary excretion via urine. Although chickens are relatively resistant to aflatoxins, contamination of feed can lead to adverse effects and thus economic losses in farming. Therefore, a biomarker method to estimate the exposure of chickens to aflatoxins can play an important role to monitor the animals' health.

Serum-free light chains adjusted for renal function are a potential biomarker for post-transplant lymphoproliferative disorders.

Post-transplant lymphoproliferative disease (PTLD) is a serious complication of solid organ transplantation. As early diagnosis remains challenging, we investigated the utility of serum-free light chain (FLC) and heavy chain/light chain pairs (HLC) as diagnostic biomarkers. Pre-treatment serum FLC and HLC levels were measured in 20 patients at their first diagnosis of B cell PTLD and in 14/20 patients during follow-up. Results were compared to serum FLC/HLC levels of 90 matched PTLD-free transplanted controls. Renal dysfunction was common in both cohorts, and combined FLC levels were often elevated above the conventional upper limit of normal (45.7 mg/L). Combined FLC levels were higher in patients with PTLD than in transplant controls (p = 0.013), and levels above the conventional ULN were associated with PTLD (OR 3.2, p = 0.05). Following adjustment to cystatin C as a marker of renal function an even stronger association was found for a (dimensionless) threshold value of 37.8 (OR 8.9, p < 0.001). In addition, monoclonal proliferation (abnormal FLC ratio, using an established renal range cutoff) was more common in PTLD than in controls (3/20 vs. 2/90, p = 0.04). Following therapy, at the time of protocolised restaging, patients experiencing subsequent sustained complete remission displayed lower FLC levels than those not experiencing such remission (p = 0.053). No relationship with HLC results was seen. Elevated polyclonal FLC levels (especially when adjusted for renal function) and monoclonal proliferation are a potential biomarker for PTLD diagnosis and disease surveillance. However, prospective validation is necessary before FLC measurement should be incorporated in follow-up of transplant recipients and PTLD management.

Towards a Full Automation of the ELISpot Assay for Safe and Parallelized Immunomonitoring.

The ELISpot assay, as a sensitive and specific method, enables the detection of cytokines for immunological purposes and in vaccine development. Here we describe the successful transfer of the manual procedure to a commercially available automated liquid handling platform, based on the work described in Neubauer et al. (Cytotechnology 69:57-73, 2017). Different kinds of technical issues (dead volume reduction, instrumental handling limitations, liquid class improvement) have been solved and biological effects (reagents concentration, selectivity tests, dispensing way, etc.) have been controlled during the implementation process. At the end a maximum of 6% mean delta difference and a lower mean dispersion than the manual assay were reached as well as a turnaround time of four to six times higher than the manual process.

Limit on Excitation and Stabilization of Atoms in Intense Optical Laser Fields.

Atomic excitation in strong optical laser fields has been found to take place even at intensities exceeding saturation. The concomitant acceleration of the atom in the focused laser field has been considered a strong link to, if not proof of, the existence of the so-called Kramers-Henneberger (KH) atom, a bound atomic system in an intense laser field. Recent findings have moved the importance of the KH atom from being purely of theoretical interest toward real world applications; for instance, in the context of laser filamentation. Considering this increasing importance, we explore the limits of strong-field excitation in optical fields, which are basically imposed by ionization through the spatial field envelope and the field propagation.

Publisher's Note:

This corrects the article DOI: 10.1103/PhysRevE.96.062702.

Two-site jumps in dimethyl sulfone studied by one- and two-dimensional 17O NMR spectroscopy.

Polycrystalline dimethyl sulfone is studied using central-transition oxygen-17 exchange NMR. The quadrupolar and chemical shift tensors are determined by combining quantum chemical calculations with line shape analyses of rigid-lattice spectra measured for stationary and rotating samples at several external magnetic fields. Quantum chemical computations predict that the largest principal axes of the chemical shift anisotropy and electrical field gradient tensors enclose an angle of about 73°. This prediction is successfully tested by comparison with absorption spectra recorded at three different external magnetic fields. The experimental one-dimensional motionally narrowed spectra and the two-dimensional exchange spectrum are compatible with model calculations involving jumps of the molecules about their two-fold symmetry axis. This motion is additionally investigated by means of two-time stimulated-echo spectroscopy which allows for a determination of motional correlation functions over a wider temperature range than previously reported using carbon and deuteron NMR. On the basis of suitable second-order quadrupolar frequency distributions, sin-sin stimulated-echo amplitudes are calculated for a two-site model in the limit of vanishing evolution time and compared with experimental findings. The present study thus establishes oxygen-17 NMR as a powerful method that will be particularly useful for the study of solids and liquids devoid of nuclei governed by first-order anisotropies.

[Optical coherence tomography in neuromyelitis optica spectrum disorders]. / Optische Kohärenztomographie bei Neuromyelitis optica-Spektrum-Erkrankungen.

Neuromyelitis optica spectrum disorders (NMOSD) are mostly relapsing inflammatory conditions of the central nervous system (CNS). In 55% of the cases of NMOSD optic neuritis (ON) is the most frequent first manifestation and can cause severe damage to the afferent visual system and the retina with resultant severe visual impairment. In recent years, investigations of the retina as part of the CNS by optical coherence tomography (OCT) has been shown to be a valid and efficient method for diagnostics and evaluation of the disease course in NMOSD. In addition, OCT not only shows severe damage of the afferent visual system due to multiple bouts of ON but also reveals NMOSD-specific intraretinal pathologies. The latter could be just as important for future differential diagnostics as for the evaluation of potential therapeutic targets. This article briefly reviews the principles of the OCT technique and describes its relevance for the diagnostics and assessment of disease course in NMOSD.

Enzymatic hydrolysis of fumonisins in the gastrointestinal tract of broiler chickens.

Fumonisins (FB) are among the most frequently detected mycotoxins in feedstuffs and finished feed, and recent data suggest that the functions of the gastrointestinal tract (GIT) in poultry species might be compromised at doses ranging from 10 to 20 mg/kg, close to field incidences and below the US and EU guidelines. Strategies are therefore necessary to reduce the exposure of poultry to FB. In the present study, we assessed the efficacy of fumonisin esterase FumD (EC 3.1.1.87, commercial name FUMzyme®) to cleave the tricarballylic acid side chains of FB, leading to the formation of non-toxic hydrolyzed fumonisins in the GIT of broiler chickens. Broiler chickens were fed for 14 d (7 to 21 d of age) 3 different diets (6 birds/cage, 6 cages/diet), i) control feed (negative control group), ii) feed contaminated with 10 mg FB/kg (FB group), and iii) feed contaminated with 10 mg FB/kg and supplemented with 100 units of FUMzyme®/kg (FB+FUMzyme® group). To determine the degree of reduction of FB in the GIT, 2 characteristics were analyzed. First, the sphinganine-to-sphingosine ratio in the serum and liver was determined as a biomarker of effect for exposure to FB. Second, the concentration of fumonisin B1 and its hydrolyzed forms was evaluated in the gizzard, the proximal and distal parts of the small intestine, and the excreta. Significantly reduced sphinganine-to-sphingosine ratios in the serum and liver of the FB+FUMzyme® group (serum: 0.15 ± 0.01; liver: 0.17 ± 0.01) compared to the FB group (serum: 0.20 ± 0.01; liver: 0.29 ± 0.03) proved that supplementation of broiler feed with FUMzyme® was effective in partially counteracting the toxic effect of dietary FB. Likewise, FB concentrations in digesta and excreta were significantly reduced in the FB+FUMzyme® group compared to the FB group (P < 0.05; up to 75%). FUMzyme® furthermore partially counteracted FB-induced up-regulation of cytokine gene expression (IL-8 and IL-10) in the jejunum. The FB group showed significantly higher gene expression of IL-8 and IL-10 compared to the negative control group (IL-8: fold change = 2.9 ± 1.1, P < 0.05; IL-10: fold change = 3.6 ± 1.4, P < 0.05), whereas IL-8 and IL-10 mRNA levels were not significantly different in the FB+FUMzyme®® group compared to the other 2 groups. In conclusion, FUMzyme® is suitable to detoxify FB in chickens and maintain gut functions.

Intravenous Hydroxypropyl ß-Cyclodextrin Formulation of Letermovir: A Phase I, Randomized, Single-Ascending, and Multiple-Dose Trial.

Letermovir is a novel antiviral in clinical development for prophylaxis against human cytomegalovirus in immunocompromised transplant recipients. This two-part, single-center, randomized, double-blind, placebo-controlled trial evaluated the safety and pharmacokinetics of a hydroxypropyl ß-cyclodextrin (HPßCD)-based intravenous formulation of letermovir in healthy women. Subjects received single, escalating doses (120, 240, 480, 720, and 960 mg; 6 letermovir, 2 placebo per cohort) or multiple, once-daily doses (240 mg; 8 letermovir, 4 placebo) of HPßCD-formulated letermovir and the associated pharmacokinetic profiles and adverse events were investigated. Single-dose and multiple-dose regimens were generally well tolerated. Single-dose escalation resulted in a slightly more-than-dose-proportional increase in the area under the letermovir plasma concentration-time curve (AUC), whereas increase in the maximal observed letermovir plasma concentration (Cmax ) was dose proportional. After once-daily dosing, accumulation ratios in AUC and Cmax were 1.22 and 1.03, respectively. The terminal half-life was 28.3 h, supporting once-daily dosing (EudraCT Number: 2012-001603-20).

Drugs in development for herpes simplex and varicella zoster virus.

The alpha-herpesviruses varicella zoster virus (VZV) and herpes simplex virus (HSV) share common features including lifelong persistence in sensory ganglia and the risk of recurrences. For both HSV and VZV, standard-of-care (SoC) is based on nucleoside analogs (NAs), which require specific activation in infected cells. These existing drugs exhibit substantial limitations, warranting the development of new and more effective drugs.

Unified Time and Frequency Picture of Ultrafast Atomic Excitation in Strong Laser Fields.

Excitation and ionization in strong laser fields lies at the heart of such diverse research directions as high-harmonic generation and spectroscopy, laser-induced diffraction imaging, emission of femtosecond electron bunches from nanotips, self-guiding, filamentation and mirrorless lasing during propagation of light in atmospheres. While extensive quantum mechanical and semiclassical calculations on strong-field ionization are well backed by sophisticated experiments, the existing scattered theoretical work aiming at a full quantitative understanding of strong-field excitation lacks experimental confirmation. Here we present experiments on strong-field excitation in both the tunneling and multiphoton regimes and their rigorous interpretation by time dependent Schrödinger equation calculations, which finally consolidates the seemingly opposing strong-field regimes with their complementary pictures. Most strikingly, we observe an unprecedented enhancement of excitation yields, which opens new possibilities in ultrafast strong-field control of Rydberg wave packet excitation and laser intensity characterization.

Towards standardized automated immunomonitoring: an automated ELISpot assay for safe and parallelized functionality analysis of immune cells.

The ELISpot assay is used for the detection of T cell responses in clinical trials and vaccine evaluations. Standardization and reproducibility are necessary to compare the results worldwide, inter- and intra-assay variability being critical factors. To assure operator safety as well as high-quality experiment performance, the ELISpot assay was implemented on an automated liquid handling platform, a Tecan Freedom EVO. After validation of the liquid handling, automated loading of plates with cells and reagents was investigated. With step by step implementation of the manual procedure and liquid dispensing optimization on the robot platform, a fully automated ELISpot assay was accomplished with plates remaining in the system from the plate blocking step to spot development. The mean delta difference amounted to a maximum of 6%, and the mean dispersion was smaller than in the manual assay. Taken together, we achieved with this system not only a lower personnel attendance but also higher throughput and a more precise and parallelized analysis. This platform has the potential to guarantee validated, safe, fast, reproducible and cost-efficient immunological and toxicological assays in the future.