An Engineered Biarylitide Cross-Linking P450 from RiPP Biosynthesis Generates Alternative Cyclic Peptides

Cytochrome-P450-mediated cross-linking of ribosomally encoded peptides (RiPPs) is rapidly expanding and displays great potential for biocatalysis. Here, we demonstrate that active site engineering of the biarylitide cross-linking enzyme P450Blt enables the formation of His-X-Tyr and Tyr-X-Tyr cross-linked peptides, thus showing how such P450s can be further exploited to produce alternate cyclic tripeptides with controlled cross-linking states.

Monoclonal Antibodies: What the Diagnostic Neuroradiologist Needs to Know

Monoclonal antibodies have become increasingly popular as novel therapeutics against a variety of diseases due to their specificity, affinity, and serum stability. Due to the nearly infinite repertoire of monoclonal antibodies, their therapeutic use is rapidly expanding, revolutionizing disease course and management, and what is now considered experimental therapy may soon become approved practice. Therefore, it is important for radiologists, neuroradiologists, and neurologists to be aware of these drugs and their possible different imaging-related manifestations, including expected and adverse effects of these novel drugs. Herein, we review the most commonly used monoclonal antibody-targeted therapeutic agents, their mechanism of action, clinical applications, and major adverse events with a focus on neurologic and neurographic effects and discuss differential considerations, to assist in the diagnosis of these conditions.

Ethical Considerations and Fairness in the Use of Artificial Intelligence for Neuroradiology

In this review, concepts of algorithmic bias and fairness are defined qualitatively and mathematically. Illustrative examples are given of what can go wrong when unintended bias or unfairness in algorithmic development occurs. The importance of explainability, accountability, and transparency with respect to artificial intelligence algorithm development and clinical deployment is discussed. These are grounded in the concept of "primum no nocere" (first, do no harm). Steps to mitigate unfairness and bias in task definition, data collection, model definition, training, testing, deployment, and feedback are provided. Discussions on the implementation of fairness criteria that maximize benefit and minimize unfairness and harm to neuroradiology patients will be provided, including suggestions for neuroradiologists to consider as artificial intelligence algorithms gain acceptance into neuroradiology practice and become incorporated into routine clinical workflow.

MAPK inhibitor sensitivity scores predict sensitivity driven by the immune infiltration in pediatric low-grade gliomas

Pediatric low-grade gliomas (pLGG) show heterogeneous responses to MAPK inhibitors (MAPKi) in clinical trials. Thus, more complex stratification biomarkers are needed to identify patients likely to benefit from MAPKi therapy. Here, we identify MAPK-related genes enriched in MAPKi-sensitive cell lines using the GDSC dataset and apply them to calculate class-specific MAPKi sensitivity scores (MSSs) via single-sample gene set enrichment analysis. The MSSs discriminate MAPKi-sensitive and non-sensitive cells in the GDSC dataset and significantly correlate with response to MAPKi in an independent PDX dataset. The MSSs discern gliomas with varying MAPK alterations and are higher in pLGG compared to other pediatric CNS tumors. Heterogenous MSSs within pLGGs with the same MAPK alteration identify proportions of potentially sensitive patients. The MEKi MSS predicts treatment response in a small set of pLGG patients treated with trametinib. High MSSs correlate with a higher immune cell infiltration, with high expression in the microglia compartment in single-cell RNA sequencing data, while low MSSs correlate with low immune infiltration and increased neuronal score. The MSSs represent predictive tools for the stratification of pLGG patients and should be prospectively validated in clinical trials. Our data supports a role for microglia in the response to MAPKi.

Ornithobacterium rhinotracheale Isolated from Turkeys over a 20-Year Period Harbor Similar Antimicrobial Susceptibility Profiles and Multidrug Resistance

Infections with Ornithobacterium rhinotracheale are causing respiratory diseases that require antibiotic treatment in poultry worldwide. In the field, this agent is known to often be resistant to many antimicrobials, complicating therapeutic interventions. Therefore, there is a clear need to monitor trends in resistance development. In the present study, antibiotic resistance profiles of 64 O. rhinotracheale strains isolated from diseased turkeys from 2002 to 2021 were investigated against 19 antimicrobial substances by the microdilution method. Susceptibility toward chloramphenicol, carbapenem, and sulfamethozaxole combination was found for all strains. Most isolates were also susceptible to penicillins (98%-100%), with the exception of oxacillin, cephalosporins (84%-100%), tetracycline (89%), and tylosin (88%). In the case of quinolones, 89% of isolates showed intermediate resistance to enrofloxacin, whereas 90% showed full resistance to nalidixic acid. Full resistance to the tested aminoglycosides and colistin was revealed for all strains. Eighteen different AMR profiles were elucidated; more than half of the isolates (53%) shared the same AMR profile. Similar susceptibility profiles of O. rhinotracheale isolates were found on the different farms, proving some stability over the years. All isolates were classified as multidrug resistant. Multiple outbreaks within a flock or in successive flocks within a farm comprised 46 O. rhinotracheale isolates. Here, occasional changes in susceptibility for some antimicrobial substances were observed. In general, most of the changes occurred in quinolones, followed by tetracycline switching mainly from intermediate resistance to full resistance and vice versa. The present surveillance provides actual data on effective antibiotic treatments in case of disease outbreaks and contributes to the One Health concept acknowledging the important link between animal and human health.

Infection dynamics of Salmonella Infantis vary considerably between chicken lines

AbstractSalmonella (S.) Infantis is the most common serovar in broilers and broiler meat in the European Union. In the field, fast-growing broilers are reported to be more affected than slow-growing and layer birds. The present study investigated the infection dynamics and immunological response of four chicken lines in the course of a S. Infantis infection. Two commercial chicken lines, Ross 308 and Hubbard ISA-JA-757, and two experimentally chicken lines, specific pathogen free (SPF) layers and broilers, were infected at 2 days of age. Investigations focused on faecal shedding, bacterial colonisation, humoral and cellular immune response in the blood. Ross and SPF broilers were mainly attributed as high shedders followed by Hubbard. SPF layers showed the least shedding. This is in agreement with the caecal colonisation, SPF layers harboured significant less bacteria. Systemic spread of S. Infantis to liver and spleen was highest in Ross being statistically significant at 7 days of age compared to the other lines. Spread of infection to in-contact birds, was noticed 5 days post infection in every line. Antibody response occurred in every chicken line from day 21 of age onwards. In contrast to the other chicken lines, significant differences in T cell subsets and monocytes/macrophages were found between infected and negative Hubbard birds at 7 days of age. Uninfected SPF birds had significant higher immune cell counts (T cell subsets, B cells and monocytes /macrophages) compared to uninfected commercial birds, a fact important for future experimental settings. The results illustrate that the infection dynamics of S. Infantis is influenced by the chicken line resulting in a higher risk of transmission to humans from fast-growing broilers.

Roadmap Consensus on Carotid Artery Plaque Imaging and Impact on Therapy Strategies and Guidelines: An International, Multispecialty, Expert Review and Position Statement

Current guidelines for primary and secondary prevention of stroke in patients with carotid atherosclerosis are based on the quantification of the degree of stenosis and symptom status. Recent publications have demonstrated that plaque morphology and composition, independent of the degree of stenosis, are important in the risk stratification of carotid atherosclerotic disease. This finding raises the question as to whether current guidelines are adequate or if they should be updated with new evidence, including imaging for plaque phenotyping, risk stratification, and clinical decision-making in addition to the degree of stenosis. To further this discussion, this roadmap consensus article defines the limits of luminal imaging and highlights the current evidence supporting the role of plaque imaging. Furthermore, we identify gaps in current knowledge and suggest steps to generate high-quality evidence, to add relevant information to guidelines currently based on the quantification of stenosis.

Sensitive Screening of New Psychoactive Substances in Serum Using Liquid-Chromatography Quadrupole Time-of-Flight Mass Spectrometry

Analysis of new psychoactive substances (NPS) still pose a challenge for many institutions due to the number of available substances and the constantly changing drug market. Both new and well-known substances keep appearing and disappearing on the market, making it hard to adapt analytical methods in a timely manner. In this study we developed a qualitative screening approach for serum samples by means of liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Samples were measured in data-dependent auto-MS/MS mode and identified by fragment spectra comparison, retention time and accurate mass. Approximately 500 NPS, including 195 synthetic cannabinoids, 180 stimulants, 86 hallucinogens, 26 benzodiazepines and 7 others were investigated. Serum samples were fortified to 1 ng/mL and 10 ng/mL concentrations to estimate approximate limits of identification. Samples were extracted using solid-phase extraction with non-endcapped C18 material and elution in two consecutive steps. Benzodiazepines were eluted in the first step, while substances of other NPS subclasses were distributed among both extracts. To determine limits of identification, both extracts were combined. 96 % (470/492) of investigated NPS were detected in 10 ng/mL samples and 88 % (432/492) were detected in 1 ng/mL samples. Stimulants stood out with higher limits of identification, possibly due to instability of certain methcathinone derivatives. However, considering relevant blood concentrations, the method provided sufficient sensitivity for stimulants as well as other NPS subclasses. Data-dependent acquisition was proven to provide high sensitivity and reliability when combined with an information-dependent preferred list, without losing its untargeted operation principle. Summarizing, the developed method fulfilled its purpose as a sensitive untargeted screening for serum samples and allows uncomplicated expansion of the spectral library to include thousands of targets.

Simultaneous quantification of 18 different phytocannabinoids in serum using a highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method

The potential therapeutic effects of various phytocannabinoids and the availability of multiple cannabis-based medicines make it desirable to have an analytical method that simultaneously quantifies a wide range of cannabinoids in blood, beyond delta-9-tetrahydrocannabinol and its metabolites. A liquid chromatography tandem mass spectrometry (LC-MS/MS) method for quantification of 18 phytocannabinoids and cannabinoid metabolites in serum was developed and validated. The method enables simultaneous detection of delta-9-tetrahydrocannabinol, cannabidiol, cannabinol, cannabigerol, cannabichromene, cannabicyclol, tetrahydrocannabivarin and cannabidivarin and their acidic precursors tetrahydocannabinolic acid A, cannabidiolic acid, cannabinolic acid, cannabigerolic acid, cannabichromenic acid, cannabicyclolic acid, tetrahydrocannabivarinic acid and cannabidivarinic acid as well as the delta-9-tetrahydrocannabinol metabolites 11-hydroxy-tetrahydrocannabinol and 11-nor-9-carboxy-tetrahydrocannabinol. Limits of detection ranged from 0.0004 to 1 ng/mL and limits of quantification ranged from 0.004 to 2 ng/mL. Calibration curves of all analytes were linear over the whole calibration range. Recovery rates of 52 to 86% were obtained for all analytes except for cannabicyclol (49%), 11-nor-9-carboxy-tetrahydrocannabinol (46%), cannabichromenic acid (44%) and cannabidivarinic acid (36%). Acceptable bias and precision data were demonstrated for all analytes. The method was successfully applied to 55 forensic serum samples, obtained from the Institute of Legal Medicine Mainz.

Outbreaks of Streptococcus gallolyticus subsp. pasteurianus in Goslings Characterized by Central Nervous Symptoms

The present report describes outbreaks of Streptococcus gallolyticus subsp. pasteurianus in young geese flocks in Austria. The flocks, comprising 160-1450 goslings of 2-3 wk of age, experienced increased mortalities The clinical signs were characterized by severe central nervous symptoms, namely leg paddling and torticollis. The postmortem investigation revealed hepatitis, splenitis, and a low amount of liquid fluid in the coelomic cavity. Livers were of fragile texture, with white necrotic areas. The latter were also found in spleens. No macroscopic lesions were seen in brains. Bacteriologic investigation followed by bacterial identification by matrix-assisted laser desorption time-of-flight mass spectrometry and phylogenetic analysis of the partial 16S rRNA region revealed the presence in heart, liver, spleen, and brain of S. gallolyticus subsp. pasteurianus. Histologic investigation revealed multifocal necrosis in liver and spleen samples together with infiltration of mononuclear cells and heterophilic granulocytes. Furthermore, in the lesions, coccoid bacteria could be identified. No histopathologic changes were observed in brain samples from goslings, except in one bird in which accumulation of coccoid bacteria in blood vessels of the brain samples was present. Antibiotic sensitivity tests revealed identical profiles for all strains, which were susceptible to penicillins, cephalosporins, chloramphenicol, imipenem, and tylosin. However, resistance was found against quinolones, aminoglycosides, tetracycline, and trimethoprim-sulfamethoxazole, which are commonly used to treat infections with gram-positive bacteria.

Surveillance of Unruptured Intracranial Saccular Aneurysms Using Noncontrast 3D-Black-Blood MRI: Comparison of 3D-TOF and Contrast-Enhanced MRA with 3D-DSA

BACKGROUND AND PURPOSE

Patients with unruptured intracranial aneurysms routinely undergo surveillance imaging to monitor growth. Angiography is the criterion standard for aneurysm diagnosis, but it is invasive. This study aimed to evaluate the accuracy and reproducibility of a 3D noncontrast black-blood MR imaging technique for unruptured intracranial aneurysm measurement in comparison with 3D-TOF and contrast-enhanced MRA, using 3D rotational angiography as a reference standard.

MATERIALS AND METHODS

Sixty-four patients (57.3 ± 10.9 years of age, 41 women) with 68 saccular unruptured intracranial aneurysms were recruited. Patients underwent 3T MR imaging with 3D-TOF-MRA, 3D black-blood MR imaging, and contrast-enhanced MRA, and they underwent 3D rotational angiography within 2 weeks. The neck, width, and height of the unruptured intracranial aneurysms were measured by 2 radiologists independently on 3D rotational angiography and 3 MR imaging sequences. The accuracy and reproducibility were evaluated by Bland-Altman plots, the coefficient of variance, and the intraclass correlation coefficient.

RESULTS

3D black-blood MR imaging demonstrates the best agreement with DSA, with the smallest limits of agreement and measurement error (coefficients of variance range, 5.87%-7.04%). 3D-TOF-MRA had the largest limits of agreement and measurement error (coefficients of variance range, 12.73%-15.78%). The average coefficient of variance was 6.26% for 3D black-blood MR imaging, 7.03% for contrast-enhanced MRA, and 15.54% for TOF-MRA. No bias was found among 3 MR imaging sequences compared with 3D rotational angiography. All 3 MR imaging sequences had excellent interreader agreement (intraclass correlation coefficient, >0.95). 3D black-blood MR imaging performed the best for patients with intraluminal thrombus (n = 10).

CONCLUSIONS

3D black-blood MR imaging achieves better accuracy for aneurysm size measurements compared with 3D-TOF, using 3D rotational angiography as a criterion standard. This noncontrast technique is promising for surveillance of unruptured intracranial aneurysms.

Drug-induced keratin 9 interaction with Hsp70 in bladder cancer cells

A pull-down experiment (co-immunoprecipitation) was performed on a T24 human bladder cancer cell lysate treated with the Hsp inhibitor VER155008 using an Hsp70 antibody attached to Dynabeads. Keratin 9, a cytoskeleton intermediate filament protein, was identified by LC MS/MS analysis. This novel finding was confirmed by Western blotting, RT-PCR, and immunocytochemistry. Other members of the keratin family of proteins have been shown to be involved in cancer progression, most recently identified to be associated with cell invasion and metastasis. The specific role of keratin 9 expression in these cells is yet to be determined.

Predictors of short-term and long-term mortality in critically ill patients admitted to the intensive care unit following allogeneic stem cell transplantation

Historically, the mortality of patients admitted to the ICU after allogeneic stem cell transplantation (alloSCT) is high. Advancements in transplantation procedures, infectious monitoring and supportive care may have improved the outcome. This study aimed to determine short-term and long-term mortality after ICU admission of patients after alloSCT and to identify prognostic clinical and transplantation-related determinants present at ICU admission for long-term outcome. A multicenter cohort study was performed to determine 30-day and 1-year mortality within 2 years following alloSCT. A total of 251 patients were included. The 30-day and 1-year mortality was 55% and 80%, respectively. Platelet count <25 × 10⁹/L (OR: 2.26, CI: 1.02-5.01) and serum bilirubin >19 μmol/L (OR: 2.47 CI: 1.08-5.65) at admission, other donor than a HLA-matched-related or HLA-matched-unrelated donor (OR: 4.59, CI: 1.49-14.1) and vasoactive medication within 24 h (OR: 2.35, CI: 1.28-4.31) were associated with increased 30-day mortality. Other donor than a HLA-matched-related or HLA-matched-unrelated donor (OR: 1.9, CI: 1.13-3.19), serum bilirubin >77 (OR: 2.05, CI: 1.28-3.30) and vasoactive medication within 24 h (OR: 1.65, CI: 1.12-2.43) were associated with increased 1-year mortality. Neutropenia was associated with decreased 30-day and 1-year mortality (OR: 0.29, CI: 0.14-0.59 and OR: 0.70, CI: 0.48-0.98). Myeloablative conditioning and T cell-depleted transplantation were not associated with increased mortality.

Hybrid 3D/2D Convolutional Neural Network for Hemorrhage Evaluation on Head CT

BACKGROUND AND PURPOSE

Convolutional neural networks are a powerful technology for image recognition. This study evaluates a convolutional neural network optimized for the detection and quantification of intraparenchymal, epidural/subdural, and subarachnoid hemorrhages on noncontrast CT.

MATERIALS AND METHODS

This study was performed in 2 phases. First, a training cohort of all NCCTs acquired at a single institution between January 1, 2017, and July 31, 2017, was used to develop and cross-validate a custom hybrid 3D/2D mask ROI-based convolutional neural network architecture for hemorrhage evaluation. Second, the trained network was applied prospectively to all NCCTs ordered from the emergency department between February 1, 2018, and February 28, 2018, in an automated inference pipeline. Hemorrhage-detection accuracy, area under the curve, sensitivity, specificity, positive predictive value, and negative predictive value were assessed for full and balanced datasets and were further stratified by hemorrhage type and size. Quantification was assessed by the Dice score coefficient and the Pearson correlation.

RESULTS

A 10,159-examination training cohort (512,598 images; 901/8.1% hemorrhages) and an 862-examination test cohort (23,668 images; 82/12% hemorrhages) were used in this study. Accuracy, area under the curve, sensitivity, specificity, positive predictive value, and negative-predictive value for hemorrhage detection were 0.975, 0.983, 0.971, 0.975, 0.793, and 0.997 on training cohort cross-validation and 0.970, 0.981, 0.951, 0.973, 0.829, and 0.993 for the prospective test set. Dice scores for intraparenchymal hemorrhage, epidural/subdural hemorrhage, and SAH were 0.931, 0.863, and 0.772, respectively.

CONCLUSIONS

A customized deep learning tool is accurate in the detection and quantification of hemorrhage on NCCT. Demonstrated high performance on prospective NCCTs ordered from the emergency department suggests the clinical viability of the proposed deep learning tool.

CeO2-x nanorods with intrinsic urease-like activity

The large-scale production and ecotoxicity of urea make its removal from wastewater a health and environmental challenge. Whereas the industrial removal of urea relies on hydrolysis at elevated temperatures and high pressure, nature solves the urea disposal problem with the enzyme urease under ambient conditions. We show that CeO2-x nanorods (NRs) act as the first and efficient green urease mimic that catalyzes the hydrolysis of urea under ambient conditions with an activity (kcat = 9.58 × 101 s-1) about one order of magnitude lower than that of the native jack bean urease. The surface properties of CeO2-x NRs were probed by varying the Ce4+/Ce3+ ratio through La doping. Although La substitution increased the number of surface defects, the reduced number of Ce4+ sites with higher Lewis acidity led to a slight decrease of their catalytic activity. CeO2-x NRs are stable against pH changes and even to the presence of transition metal ions like Cu2+, one of the strongest urease inhibitors. The low costs and environmental compatibility make CeO2-x NRs a green urease substitute that may be applied in polymer membranes for water processing or filters for the waste water reclamation. The biomimicry approach allows the application of CeO2-x NRs as functional enzyme mimics where the use of native or recombinant enzyme is hampered because of its costs or operational stability.

An ultra-high vacuum scanning tunneling microscope operating at sub-Kelvin temperatures and high magnetic fields for spin-resolved measurements

We present the construction and performance of an ultra-low-temperature scanning tunneling microscope (STM), working in ultra-high vacuum (UHV) conditions and in high magnetic fields up to 9 T. The cryogenic environment of the STM is generated by a single-shot ³He magnet cryostat in combination with a ⁴He dewar system. At a base temperature (300 mK), the cryostat has an operation time of approximately 80 h. The special design of the microscope allows the transfer of the STM head from the cryostat to a UHV chamber system, where samples and STM tips can be easily exchanged. The UHV chambers are equipped with specific surface science treatment tools for the functionalization of samples and tips, including high-temperature treatments and thin film deposition. This, in particular, enables spin-resolved tunneling measurements. We present test measurements using well-known samples and tips based on superconductors and metallic materials such as LiFeAs, Nb, Fe, and W. The measurements demonstrate the outstanding performance of the STM with high spatial and energy resolution as well as the spin-resolved capability.

Confirmation of metabolites of the neuroleptic drug prothipendyl using human liver microsomes, specific CYP enzymes and authentic forensic samples-Benefit for routine drug testing

Metabolism of the tricyclic azaphenothiazine neuroleptic drug prothipendyl was investigated with in vitro studies using human liver microsomes but also specific isoforms of cytochrome P450 (CYP) enzymes. Identification and analysis of metabolites was done by liquid chromatography (LC) coupled with quadrupole time of flight mass spectrometry (LC-QTOF-MS) as well as triple quadrupole mass spectrometry (LC-QQQ-MS). Results of the herein presented study revealed the proof of various demethylated and oxidized metabolites (-CH₂, -C₂H₄, four derivatives of prothipendyl +O and three derivatives of prothipendyl -CH₂+O). Metabolic reactions of prothipendyl were mainly catalyzed by CYP enzymes CYP1A2, CYP2D6, CYP2C19 and CYP3A4. N-demethyl-prothipendyl was predominantly formed by isoforms CYP2C19 and CYP1A2, while particularly the CYP isoenzyme 3A4 was responsible for the formation of prothipendyl sulfoxide. To confirm the formation of previously identified metabolites in vivo, cardiac blood samples that were tested positive for prothipendyl during routine drug testing and serum and urine samples, collected after a voluntary intake of prothipendyl, were analyzed by LC-QQQ-MS. All metabolites of prothipendyl were proven in these authentic specimens. Neither in serum samples nor in urine samples, a prolonged detectability of metabolites in comparison to prothipendyl could be demonstrated.

Topical application of THC containing products is not able to cause positive cannabinoid finding in blood or urine

A male driver was checked during a traffic stop. A blood sample was collected 35min later and contained 7.3ng/mL THC, 3.5ng/mL 11-hydroxy-THC and 44.6ng/mL 11-nor-9-carboxy-THC. The subject claimed to have used two commercially produced products topically that contained 1.7ng and 102ng THC per mg, respectively. In an experiment, three volunteers (25, 26 and 34 years) applied both types of salves over a period of 3days every 2-4h. The application was extensive (50-100cm²). Each volunteer applied the products to different parts of the body (neck, arm/leg and trunk, respectively). After the first application blood and urine samples of the participants were taken every 2-4h until 15h after the last application (overall n=10 urine and n=10 blood samples, respectively, for each participant). All of these blood and urine samples were tested negative for THC, 11-hydroxy-THC and 11-nor-9-carboxy-THC by a GC-MS method (LoD (THC)=0.40ng/mL; LoD (11-hydroxy-THC)=0.28ng/mL; LoD (THC-COOH)=1.6ng/mL;. LoD (THC-COOH in urine)=1.2ng/mL). According to our studies and further literature research on in vitro testing of transdermal uptake of THC, the exclusive application of (these two) topically applied products did not produce cannabinoid findings in blood or urine.

Inter-individual differences in HLA expression can impact the CDC crossmatch

How human leucocyte antigen (HLA) expression levels on human lymphocytes relate to clinically relevant in vitro cytotoxicity testing has not been defined. Here, cross-sectional (n = 14) and longitudinal (n = 6) semi-quantitative assessment of HLA expression on lymphocytes was performed. Complement-dependent cytotoxicity (CDC) and cellular allo-reactivity were assessed vis-à-vis target cells with defined levels of HLA expression. On CD4(+) and CD8(+) T-cells, and on B-cells, intra-individual HLA levels varied ≤1.5-fold, whereas inter-individual HLA expression varied 2.34-fold and 2.07-fold on CD4(+) and CD8(+) T-cells, respectively, and 2.90-fold on B-cells. Importantly, CDC crossmatch reactions induced by anti-HLA-A2 monoclonal antibody as well as patient sera solely containing HLA-A2 antibodies were significantly impacted by HLA-A2 expression levels on donor cells. Likewise, cytotoxicity of HLA-A2 reactive effector cells was induced proportionate to availability of HLA-A2. These data demonstrate that human HLA expression on lymphocytes from healthy blood donors is fairly stable intra-individually, yet varies significantly from person to person. Variability in HLA expression levels can impact functional cytotoxic reactions in vitro, including the widely used CDC crossmatch assay. Prospective studies are required to test the clinical relevance of this finding.

The Swiss National Registry for Primary Immunodeficiencies: report on the first 6 years' activity from 2008 to 2014

The Swiss National Registry for Primary Immunodeficiency Disorders (PID) was established in 2008, constituting a nationwide network of paediatric and adult departments involved in the care of patients with PID at university medical centres, affiliated teaching hospitals and medical institutions. The registry collects anonymized clinical and genetic information on PID patients and is set up within the framework of the European database for PID, run by the European Society of Immunodeficiency Diseases. To date, a total of 348 patients are registered in Switzerland, indicating an estimated minimal prevalence of 4·2 patients per 100 000 inhabitants. Distribution of different PID categories, age and gender are similar to the European cohort of currently 19 091 registered patients: 'predominantly antibody disorders' are the most common diseases observed (n = 217/348, 62%), followed by 'phagocytic disorders' (n = 31/348, 9%). As expected, 'predominantly antibody disorders' are more prevalent in adults than in children (78 versus 31%). Within this category, 'common variable immunodeficiency disorder' (CVID) is the most prevalent PID (n = 98/217, 45%), followed by 'other hypogammaglobulinaemias' (i.e. a group of non-classified hypogammaglobulinaemias) (n = 54/217, 25%). Among 'phagocytic disorders', 'chronic granulomatous disease' is the most prevalent PID (n = 27/31, 87%). The diagnostic delay between onset of symptoms and diagnosis is high, with a median of 6 years for CVID and more than 3 years for 'other hypogammaglobulinaemias'.

Creation and application of voxelised dosimetric models, and a comparison with the current methodology as used for the International Commission on Radiological Protection's Reference Animals and Plants

Over the past decade, the International Commission on Radiological Protection (ICRP) has developed a comprehensive approach to environmental protection that includes the use of Reference Animals and Plants (RAPs) to assess radiological impacts on the environment. For the purposes of calculating radiation dose, the RAPs are approximated as simple shapes that contain homogeneous distributions of radionuclides. As uncertainties in environmental dose effects are larger than uncertainties in radiation dose calculation, some have argued against more realistic dose calculation methodologies. However, due to the complexity of organism morphology, internal structure, and density, dose rates calculated via a homogenous model may be too simplistic. The purpose of this study is to examine the benefits of a voxelised phantom compared with simple shapes for organism modelling. Both methods typically use Monte Carlo methods to calculate absorbed dose, but voxelised modelling uses an exact three-dimensional replica of an organism with accurate tissue composition and radionuclide source distribution. It is a multi-stage procedure that couples imaging modalities and processing software with Monte Carlo N-Particle. These features increase dosimetric accuracy, and may reduce uncertainty in non-human biota dose-effect studies by providing mechanistic answers regarding where and how population-level dose effects arise.

The ultrasound compression sign to diagnose temporal giant cell arteritis shows an excellent interobserver agreement

OBJECTIVES

To compare the diagnostic performance between a vascular specialist and a rheumatologist not familiar with vascular ultrasound when applying the compression sign for the diagnosis of temporal arteritis.

METHODS

Sixty consecutive patients with suspicion of giant cell arteritis were examined by both examiners. Compression of the temporal artery on both sides (stem and both branches) was performed to define whether signs of vasculitis, no vasculitis or an indefinite result were present. Each examiner was blinded to the result of the other.

RESULTS

In 59/60 patients, the examiners found an identical result. The interobserver agreement (Krippendorf alpha) was 0.92.

CONCLUSIONS

The new compression sign for the diagnosis of temporal arteritis is a simple and robust sonographic marker with an excellent interobserver agreement.

Risk factors for pneumocystis pneumonia in giant cell arteritis: a single-centre cohort study

OBJECTIVES

Pneumocystis jiroveci pneumonia (PCP) is a life-threatening opportunistic infection. Few PCP cases in giant cell arteritis (GCA) have been described, but it remains unknown, which patients need PCP prophylaxis.

METHODS

Sixty-two patients with GCA from a prospective cohort were studied to identify treatment-related predictors of PCP infection.

RESULTS

Four PCP infections occurred, all in patients treated with methotrexate in addition to prednisone. Moreover, PCP is associated with higher cumulative PDN doses and severe lymphocytopenia (<400/μl).

CONCLUSIONS

Our findings support PCP-prophylaxis in GCA patients who are treated with methotrexate and PDN, and need high prednisone doses to achieve remission, or develop severe lymphocytopenia.

Composition of diet modifies colonization dynamics of Campylobacter jejuni in broiler chickens

AIMS

To evaluate the impact of diet composition on colonization dynamics of Camp. jejuni and on related physiological parameters in the chicken intestine.

METHODS AND RESULTS

A total of 54 1-day-old Ross 308 broiler chicks were randomly divided into three isocaloric and isonitrogenous dietary groups: maize-based (MB), wheat-based (WB) diet and wheat-based diet with NSP-degrading enzyme supplementation (WBES). Chickens were orally infected with 10(8)  CFU Camp. jejuni on day 14, and samples (n = 6) were collected on 7, 14 and 21 days postinfection (DPI), respectively. Colony forming units of Camp. jejuni of caecum and jejunum, short-chain fatty acid (SCFA) concentrations, pH values of the caecum, jejunal histomorphology and viscosity of jejunal chymus were measured. In case of WBES diet, lower Camp. jejuni colonization 14 DPI, higher jejunal viscosity, higher total SCFA concentrations in the caecum and enhanced jejunal histomorphology were observed compared to those measured in chickens fed MB diet.

CONCLUSIONS

The WBES diet altered Camp. jejuni colonization dynamics in the chicken intestine which resulted by higher SCFA concentrations in the caecum and by the change of gut morphology.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our study proves that diet composition can modify Camp. jejuni colonization depending on sampling time point postinfection.

Thin film growth of Fe-based superconductors: from fundamental properties to functional devices. A comparative review

Fe-based superconductors bridge a gap between MgB2 and the cuprate high temperature superconductors as they exhibit multiband character and transition temperatures up to around 55 K. Investigating Fe-based superconductors thus promises answers to fundamental questions concerning the Cooper pairing mechanism, competition between magnetic and superconducting phases, and a wide variety of electronic correlation effects. The question addressed in this review is, however, is this new class of superconductors also a promising candidate for technical applications? Superconducting film-based technologies range from high-current and high-field applications for energy production and storage to sensor development for communication and security issues and have to meet relevant needs of today’s society and that of the future. In this review we will highlight and discuss selected key issues for Fe-based superconducting thin film applications. We initially focus our discussion on the understanding of physical properties and actual problems in film fabrication based on a comparison of different observations made in the last few years. Subsequently we address the potential for technological applications according to the current situation.

Soft-X-ray ARPES facility at the ADRESS beamline of the SLS: concepts, technical realisation and scientific applications

Soft-X-ray angle-resolved photoelectron spectroscopy (ARPES) with photon energies around 1 keV combines the momentum space resolution with increasing probing depth. The concepts and technical realisation of the new soft-X-ray ARPES endstation at the ADRESS beamline of SLS are described. The experimental geometry of the endstation is characterized by grazing X-ray incidence on the sample to increase the photoyield and vertical orientation of the measurement plane. The vacuum chambers adopt a radial layout allowing most efficient sample transfer. High accuracy of the angular resolution is ensured by alignment strategies focused on precise matching of the X-ray beam and optical axis of the analyzer. The high photon flux of up to 10(13) photons s(-1) (0.01% bandwidth)(-1) delivered by the beamline combined with the optimized experimental geometry break through the dramatic loss of the valence band photoexcitation cross section at soft-X-ray energies. ARPES images with energy resolution up to a few tens of meV are typically acquired on the time scale of minutes. A few application examples illustrate the power of our advanced soft-X-ray ARPES instrumentation to explore the electronic structure of bulk crystals with resolution in three-dimensional momentum, access buried heterostructures and study elemental composition of the valence states using resonant excitation.

Design and properties of a cryogenic dip-stick scanning tunneling microscope with capacitive coarse approach control

We present the design, setup, and operation of a new dip-stick scanning tunneling microscope. Its special design allows measurements in the temperature range from 4.7 K up to room temperature, where cryogenic vacuum conditions are maintained during the measurement. The system fits into every (4)He vessel with a bore of 50 mm, e.g., a transport dewar or a magnet bath cryostat. The microscope is equipped with a cleaving mechanism for cleaving single crystals in the whole temperature range and under cryogenic vacuum conditions. For the tip approach, a capacitive automated coarse approach is implemented. We present test measurements on the charge density wave system 2H-NbSe2 and the superconductor LiFeAs which demonstrate scanning tunneling microscopy and spectroscopy data acquisition with high stability, high spatial resolution at variable temperatures and in high magnetic fields.

Evidence for a vortex-glass transition in superconducting Ba(Fe0.9Co0.1)2As2

Measurements of magneto-resistivity and magnetic susceptibility were performed on single crystals of superconducting Ba(Fe0.9Co0.1)2As2 close to the conditions of optimal doping. The high quality of the investigated samples allows us to reveal dynamic scaling behaviour associated with a vortex-glass phase transition in the limit of a weak degree of quenched disorder. Accordingly, the dissipative component of the ac susceptibility is reproduced well within the framework of Havriliak-Negami relaxation, assuming a critical power-law divergence for the characteristic correlation time τ of the vortex dynamics. Remarkably, the random disorder introduced by the Fe1-xCox chemical substitution is found to act on the vortices as a much weaker quenched disorder than previously reported for cuprate superconductors such as Y1-xPrxBa2Cu3O7-δ.

Low temperature ballistic spin transport in the S = 1/2 antiferromagnetic Heisenberg chain compound SrCuO2

We report zero and longitudinal magnetic field muon spin relaxation (μSR) measurements of the spin S = 1/2 antiferromagnetic Heisenberg chain material SrCuO2. We find that in a weak applied magnetic field B0 the spin-lattice relaxation rate λ follows a power law λ is proportional to B(0)(-n) with n = 0.9(3). This result is temperature independent for 5 K ≤ T ≤ 300 K. Within conformal field theory and using the Müller ansatz we conclude ballistic spin transport in SrCuO2.

Spin pseudogap in Ni-doped SrCuO2

The S=1/2 spin chain material SrCuO2 doped with 1% S=1 Ni impurities is studied by inelastic neutron scattering. At low temperatures, the spectrum shows a pseudogap Δ≈8  meV, absent in the parent compound, and not related to any structural phase transition. The pseudogap is shown to be a generic feature of quantum spin chains with dilute defects. A simple model based on this idea quantitatively accounts for the experimental data measured in the temperature range from 2 to 300 K, and allows us to represent the momentum-integrated dynamic structure factor in a universal scaling form.

Novel in situ cell for Raman diagnostics of lithium-ion batteries

A novel in situ cell for Raman diagnostics of working lithium-ion batteries is described. The design closely mimics that of standard battery testing cells and therefore allows to obtain Raman spectra under representative electrochemical conditions. Both cathode and anode materials can be studied. First results on the intercalation of a Li1-xCoO2 cathode material demonstrate the potential of the experimental approach for structural studies and underline the importance of studying lithium-ion batteries at work.