Consistency of convolutional neural networks in dermoscopic melanoma recognition: A prospective real-world study about the pitfalls of augmented intelligence

BACKGROUND

Deep-learning convolutional neural networks (CNNs) have outperformed even experienced dermatologists in dermoscopic melanoma detection under controlled conditions. It remains unexplored how real-world dermoscopic image transformations affect CNN robustness.

OBJECTIVES

To investigate the consistency of melanoma risk assessment by two commercially available CNNs to help formulate recommendations for current clinical use.

METHODS

A comparative cohort study was conducted from January to July 2022 at the Department of Dermatology, University Hospital Basel. Five dermoscopic images of 116 different lesions on the torso of 66 patients were captured consecutively by the same operator without deliberate rotation. Classification was performed by two CNNs (CNN-1/CNN-2). Lesions were divided into four subgroups based on their initial risk scoring and clinical dignity assessment. Reliability was assessed by variation and intraclass correlation coefficients. Excisions were performed for melanoma suspicion or two consecutively elevated CNN risk scores, and benign lesions were confirmed by expert consensus (n = 3).

RESULTS

117 repeated image series of 116 melanocytic lesions (2 melanomas, 16 dysplastic naevi, 29 naevi, 1 solar lentigo, 1 suspicious and 67 benign) were classified. CNN-1 demonstrated superior measurement repeatability for clinically benign lesions with an initial malignant risk score (mean variation coefficient (mvc): CNN-1: 49.5(±34.3)%; CNN-2: 71.4(±22.5)%; p = 0.03), while CNN-2 outperformed for clinically benign lesions with benign scoring (mvc: CNN-1: 49.7(±22.7)%; CNN-2: 23.8(±29.3)%; p = 0.002). Both systems exhibited lowest score consistency for lesions with an initial malignant risk score and benign assessment. In this context, averaging three initial risk scores achieved highest sensitivity of dignity assessment (CNN-1: 94%; CNN-2: 89%). Intraclass correlation coefficients indicated 'moderate'-to-'good' reliability for both systems (CNN-1: 0.80, 95% CI:0.71-0.87, p < 0.001; CNN-2: 0.67, 95% CI:0.55-0.77, p < 0.001).

CONCLUSIONS

Potential user-induced image changes can significantly influence CNN classification. For clinical application, we recommend using the average of three initial risk scores. Furthermore, we advocate for CNN robustness optimization by cross-validation with repeated image sets.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT04605822).

The fluorochrome-to-protein ratio is crucial for the flow cytometric detection of tissue factor on extracellular vesicles

Extracellular vesicles (EVs) have crucial roles in hemostasis and coagulation. They sustain coagulation by exposing phosphatidylserine and initiate clotting by surface expression of tissue factor (TF) under inflammatory conditions. As their relevance as biomarkers of coagulopathy is increasingly recognized, there is a need for the sensitive and reliable detection of TF+ EVs, but their flow cytometric analysis is challenging and has yielded controversial findings for TF expression on EVs in the vascular system. We investigated the effect of different fluorochrome-to-protein (F/P) ratios of anti-TF-fluorochrome conjugates on the flow cytometric detection of TF+ EVs from activated monocytes, mesenchymal stem cells (MSCs), and in COVID-19 plasma. Using a FITC-labeled anti-TF antibody (clone VD8), we show that the percentage of TF+ EVs declined with decreasing F/P ratios. TF was detected on 7.6%, 5.4%, and 1.1% of all EVs derived from activated monocytes at F/P ratios of 7.7:1, 6.6:1, and 5.2:1. A similar decline was observed for EVs from MSCs and for EVs in plasma, whereas the detection of TF on cells remained unaffected by different F/P ratios. We provide clear evidence that next to the antibody clone, the F/P ratio affects the flow cytometric detection of TF+ EVs and should be carefully controlled.

[Five case reports on granulosa cell tumors in cattle with practical information on diagnosis and possible progression]

INTRODUCTION

Five cases of ovarian tumors (granulosa cell tumors) in cattle are presented from the patient load of the Vetsuisse University of Zurich and Bern. The aim of this work was to demonstrate the variable development of the illness and to indicate diagnostic and therapeutic possibilities to the practicing veterinarians. Case 1 shows bilateral appearance and the development of malignancy and metastases. The main symptoms in case 2 were the development of the mammary gland in a juvenile animal and the behavior modification due to a hormonal imbalance. The cases 3, 4 and 5 underwent surgery, case 4 restarted reproductive activity resulting in five subsequent pregnancies. The initial presumption is a result of a gynecological including ultrasonographic examination and can be verified by the analysis of Müllerian Inhibiting Hormone in serum. The decision to perform surgery should be done rapidly, as normal fertility can be achieved if the tumor is located unilaterally. Tumor growth and potential malignancy can provoke fatal health issues and also make it impossible to use meat of these animals for consumption.

Detection of Cleaved Stx2a in the Blood of STEC-Infected Patients

Typical hemolytic uremic syndrome (HUS) is mainly caused by Shiga toxin-producing Escherichia coli (STEC) releasing Shiga toxin 2 (Stx2). Two different structures of this AB5 toxin have been described: uncleaved, with intact B and A chains, and cleaved, with intact B and a nicked A chain consisting of two fragments, A1 and A2, connected by a disulfide bond. Despite having the same toxic effect on sensitive cells, the two forms differ in their binding properties for circulating cells, serum components and complement factors, thus contributing to the pathogenesis of HUS differently. The outcome of STEC infections and the development of HUS could be influenced by the relative amounts of uncleaved or cleaved Stx2 circulating in patients' blood. Cleaved Stx2 was identified and quantified for the first time in four out of eight STEC-infected patients' sera by a method based on the inhibition of cell-free translation. Cleaved Stx2 was present in the sera of patients with toxins bound to neutrophils and in two out of three patients developing HUS, suggesting its involvement in HUS pathogenesis, although in association with other bacterial or host factors.

Comparison of linear and non-linear decision boundaries to detect feedlot bloat using intensive data collection systems on Angus × Hereford steers

Ruminal tympany (bloat) has long been an issue for large and small livestock operations. Though improvements in feedlot management practices have reduced its occurrence, it is still highly prevalent and is known to detrimentally affect animal performance, welfare, and in many instances, lead to animal death. Current decision support systems and diet formulation software omit the inclusion of bloat prediction based on animal performance. Here, we aim to predict bloat incidence in implanted and non-implanted feedlot steers from performance data comparing linear (LDB) and non-linear decision boundaries. Eighteen crossbred Angus × Hereford steers: BW (491.13 ± 25.78 kg) and age (12 ± 1 mo) were randomly distributed into implanted and non-implanted treatments. All animals were randomly assigned to one of two pens fit with automated monitoring systems for BW, freshwater intake, and water intake behavior: water intake event visit, no water intake event visit (NWIE), and time spent drinking. DM intake (DMI) was individually recorded from all animals through the Calan Gate system for 135 d (30 d adaptation, 105 d experimental diet). Incidences of bloat were recorded as bloat instances regardless of severity to ensure that early onset detection of bloat was recorded and properly identified in predictive models. Logistic regression with a binomial distribution and a logit link function was utilized to predict the incidences of bloat through LDB. Feature selection and penalization of coefficients were explored through L1 (sum of absolute values) and L2 (sum of squares) penalization to avoid overfitting of models. Additional NLDB and a non-parametric LDB are examined for prediction. Accuracy, specificity, and sensitivity were high for the models reported. No significant differences were observed between LDB and NLDB, with the highest specificity (predicting bloat) value of 0.820 for stepwise feature selection algorithms, and a value of 0.832 for the artificial neural network. Highest accuracy was 0.829 for ridge regression, and 0.847 for the random forest with hyperparameter tuning. DM intake, BW, and NWIE were the three most important variables for the prediction of feedlot bloat showing clear drops in DMI and BW and increases in NWIE when animals bloated. The lack of difference in predictive performance between LDB and NLDB highlights the often-overlooked concept that machine learning algorithms are not always the only/best modeling technique. Additionally, the models reported herein carry acceptable predictive performance for inclusion into management decisions that reduce bloat incidences in feedlot cattle.

Expression of Tissue Factor and Platelet/Leukocyte Markers on Extracellular Vesicles Reflect Platelet-Leukocyte Interaction in Severe COVID-19

Severe COVID-19 is frequently associated with thromboembolic complications. Increased platelet activation and platelet-leukocyte aggregate formation can amplify thrombotic responses by inducing tissue factor (TF) expression on leukocytes. Here, we characterized TF-positive extracellular vesicles (EVs) and their cellular origin in 12 patients suffering from severe COVID-19 (time course, 134 samples overall) and 25 healthy controls. EVs exposing phosphatidylserine (PS) were characterized by flow cytometry. Their cellular origin was determined by staining with anti-CD41, anti-CD45, anti-CD235a, and anti-CD105 as platelet, leukocyte, red blood cell, and endothelial markers. We further investigated the association of EVs with TF, platelet factor 4 (PF4), C-reactive protein (CRP), and high mobility group box-1 protein (HMGB-1). COVID-19 patients showed higher levels of PS-exposing EVs compared to controls. The majority of these EVs originated from platelets. A higher amount of EVs in patient samples was associated with CRP, HMGB-1, PF4, and TF as compared to EVs from healthy donors. In COVID-19 samples, 16.5% of all CD41+ EVs displayed the leukocyte marker CD45, and 55.5% of all EV aggregates (CD41+CD45+) co-expressed TF, which reflects the interaction of platelets and leukocytes in COVID-19 on an EV level.

Enzymatic Cleavage of Stx2a in the Gut and Identification of Pancreatic Elastase and Trypsin as Possible Main Cleavers

Shiga toxins (Stxs), especially the Stx2a subtype, are the major virulence factors involved in enterohemorrhagic Escherichia coli (EHEC)-associated hemolytic uremic syndrome (eHUS), a life-threatening disease causing acute kidney injury, especially in children. After oral transmission and colonization in the gut, EHEC release Stx. Intracellular cleavage of the Stx A subunit, when followed by reduction, boosts the enzymatic activity that causes damage to targeted cells. This cleavage was assumed to be mostly mediated by furin during Stx intracellular trafficking. To investigate whether this cleavage could occur in the intestine, even prior to entering target cells, Stx2a A subunit structure (intact or cleaved) was characterized after its exposure to specific host factors present in human stool. The molecular weight of Stx2a A subunit/fragments was determined by immunoblotting after electrophoretic separation under reducing conditions. In this study, it was demonstrated that Stx2a is cleaved by certain human stool components. Trypsin and chymotrypsin-like elastase 3B (CELA3B), two serine proteases, were identified as potential candidates that can trigger the extracellular cleavage of Stx2a A subunit directly after its secretion by EHEC in the gut. Whether the observed cleavage indeed translates to natural infections and plays a role in eHUS pathogenesis has yet to be determined. If so, it seems likely that a host's protease profile could affect disease development by changing the toxin's biological features.

Prognostic factors and predictive scores for 6-months mortality of hematopoietic stem cell transplantation recipients admitted to the pediatric intensive care unit

Objective

Despite advances in hematopoietic stem cell transplantation (HSCT), a considerable number of pediatric HSCT patients develops post-transplant complications requiring admission to the pediatric intensive care unit (PICU). The objective of this study was to evaluate clinical findings, PICU supportive therapy and outcome as well as predictive factors for 6-months survival after discharge of HSCT patients from PICU.

Study design

This retrospective single-center analysis investigated patient characteristics, microbiological findings, reasons for admission and death of 54 cases accounting for 94 admissions to the PICU of the University Children's Hospital Tuebingen from 2002 to 2017. We compared clinical characteristics between children with and without 6-months survival after discharge from PICU following HSCT. Finally, we assessed the potential prognostic value of the oncological Pediatric Risk of Mortality Score (O-PRISM), the Pediatric Sequential Organ Failure Assessment Score (pSOFA) and the pRIFLE Criteria for Acute Kidney Injury for 6-months survival using Generalized Estimating Equations (GEE) and Receiver Operating Characteristic curves.

Results

Respiratory insufficiency, gastroenterological problems and sepsis were the most common reasons for PICU admission. Out of 54 patients, 38 (70%) died during or after their last PICU admission, 30% survived for at least six months. When considering only first PICU admissions, we could not determine prognostic factors for 6-months mortality. In contrast, under consideration of all PICU admissions in the GEE model, ventilation (p=0.03) and dialysis (p=0.007) were prognostic factors for 6-months mortality. Furthermore, pSOFA (p=0.04) and O-PRISM (p=0.02) were independent risk factors for 6-months mortality considering all PICU admissions.

Conclusion

Admission of HSCT patients to PICU is still associated with poor outcome and 69% of patients died within 6 months. Need for respiratory support and dialysis are associated with poor outcome. Prediction of 6-months survival is difficult, especially during a first PICU admission. However, on subsequent PICU admissions pSOFA and O-PRISM scores might be useful to predict mortality. These scores should be prospectively evaluated in further studies to verify whether they can identify pediatric HSCT recipients profiting most from transferal to the PICU.

EPA Consensus Project Paper: Accuracy of Photogrammetry Devices, Intraoral Scanners, and Conventional Techniques for the Full-Arch Implant Impressions: A Systematic Review

PURPOSE

The objective of this systematic review was to evaluate and compare the accuracy of digital impression techniques and conventional methods for full-arch implant impressions.

METHODS

An electronic literature search in the databases Medline (Pubmed), Web of Science, and Embase was performed to identify in vitro and in vivo publications (between 2016 and 2022) directly comparing digital and conventional abutment-level impression techniques. All selected articles passed through the data extraction procedure according to defined parameters in inclusion and exclusion criteria. Measurements on linear, angular and/or surface deviations were performed in all selected articles.

RESULTS

Nine studies met the inclusion criteria and were selected for this systematic review. 3 articles were clinical studies and 6 studies were in vitro. Accuracy difference mean values of the trueness up to 162+/-77μm between digital and conventional techniques were reported in the clinical studies and up to 43μm in laboratory studies. Methodological heterogeneity was observed in both, in vivo and in vitro studies.

CONCLUSIONS

Intraoral scanning and photogrammetric method showed comparable accuracy for registering implant positions in the full-arch edentulous cases. A tolerable implant prosthesis misfit threshold and objective misfit assessment criteria (for linear and angular deviations) should be verified in clinical studies.

Infection with SARS-CoV-2 Is Associated with Elevated Levels of IP-10, MCP-1, and IL-13 in Sepsis Patients

Immunothrombosis, an excessive inflammatory response with simultaneous overactivation of the coagulation system, is a central pathomechanism in sepsis and COVID-19. It is associated with cellular activation, vascular damage, and microvascular thrombosis, which can lead to multiple organ failure and death. Here, we characterized factors related to immunothrombosis in plasma samples from 78 sepsis patients. In the course of routine clinical testing, SARS-CoV-2 was detected in 14 of these patients. Viral infection was associated with a higher mortality. Both, COVID-19 negative and COVID-19 positive sepsis patients showed increased levels of effectors of immunothrombosis, including platelet factor 4, D-dimer, nucleosomes, citrullinated histone H3, high mobility group box-1 protein, as well as phosphatidylserine-expressing platelet-derived extracellular vesicles, compared to healthy controls (n = 25). Using a 27-plex cytokine bead array, we found that Interleukin (IL)-1ra, IL-6, IL-8, IL-13, tumor necrosis factor (TNF)-α, interferon inducible protein (IP)-10, monocyte chemotactic protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, and granulocyte-colony stimulating factor (G-CSF) were elevated in both, COVID-19 negative and COVID-19 positive sepsis patients, as compared to healthy controls. SARS-CoV-2 infection was associated with elevated levels of IP-10, MCP-1, and IL-13, while all other mediators widely overlapped between COVID-19 negative and COVID-19 positive patients.

Physiological stretching induces a differential extracellular matrix gene expression response in acetabular labrum cells

The acetabular labrum is a fibrocartilaginous ring surrounding the acetabulum and is important for hip stability and contact pressure dissipation through a sealing function. Injury of the labrum may contribute to hip-joint degeneration and development of secondary osteoarthritis. Understanding how extracellular matrix (ECM) production and remodelling is regulated is of key importance for successful tissue restoration. The present study hypothesised that physiological stretching enhanced the metabolic activity and altered the ECM gene expression in labrum cells. Primary bovine labrum cells were physiologically stretched for up to 5 d. 24 h after the last stretch cycle, changes in metabolic activity were measured using the PrestoBlue™ HS Cell Viability Reagent and ECM gene expression was examined using the quantitative polymerase chain reaction method. Targets of interest were further investigated using immunofluorescence and enzyme-linked immunosorbent assay. Metabolic activity was not affected by the stretching (0.9746 ± 0.0614, p > 0.05). Physiological stretching upregulated decorin (DCN) (1.8548 ± 0.4883, p = 0.002) as well as proteoglycan 4 (PRG4) (1.7714 ± 0.6600, p = 0.029) and downregulated biglycan (BGN) (0.7018 + 0.1567, p = 0.008), cartilage oligomeric matrix protein (COMP) (0.5747 ± 0.2650, p = 0.029), fibronectin (FN1) (0.5832 ± 0.0996, p < 0.001) and spondin 1 (SPON1) (0.6282 ± 0.3624, p = 0.044) gene expression. No difference in PRG4 and DCN abundance or release could be measured. The here identified mechanosensitive targets are known to play relevant roles in tissue organisation. Therefore, physiological stretching might play a role in labrum tissue homeostasis and regeneration.

Regimen of Coronavirus Disease 2019 Vaccination Influences Extent and Kinetics of Antibody Avidity

We investigated antibody titers and avidity after heterologous versus homologous coronavirus disease 2019 vaccination over 6 months after the second dose. We found a significantly higher avidity in regimens including at least 1 dose of the adenoviral vector vaccine ChAdOx1-S compared with 2 doses of the mRNA vaccine BNT162b2.

P03.07.A MRI signature in preoperative imaging predicts mesenchymal stem cell features and radioresistance in primary glioblastoma stem cell cultures

Background

Recently, a molecular signature describing the mesenchymal / proneural features of primary stem-cell-enriched glioblastoma cultures was identified correlating with invasiveness, radiation sensitivity and patient-outcome. However, generating and characterizing primary cultures is time-consuming and this might hamper translation into clinical concepts. The aim of this study was to evaluate the use of standard preoperative MR imaging (T1ce and T2FLAIR sequences) to predict the molecular signature and thus enable the development of clinical treatment concepts based on the molecular properties of the individual tumors.

Material and Methods

For 16 patients, for whom primary stem cell enriched cultures had been characterized for their mesenchymal / proneural signature and radiation sensitivity, tumor volume (hyperintense volume in T1ce), necrosis (hypointense volume inside the tumor volume) and edema (hyperintense volume in T2FLAIR) were contoured for volumetric analysis. Volume parameters were used to calculate ratios (edema/tumor and necrosis/tumor) and a MRI signature, which was then correlated with molecular parameters and patient outcome stratified by MGMT promoter methylation.

Results

As expected, the prognosis of patients with MGMT-promoter-methylated tumors was better (n.s.) compared to those with unmethylated MGMT promoters. Neither molecular nor imaging data were significantly different between these subgroups. In the subgroup of patients with unmethylated MGMT promoter, volumetric imaging parameters correlated with the molecular signature and cellular radiation sensitivity of the stem cell enriched cultures. This association was much weaker in the subgroup with methylated MGMT promoter.

Conclusion

In the subgroup of patients with unmethylated MGMT promoter, volumetric parameters on preoperative standard MR imaging might hint at the molecular properties of the respective tumor and its radiation sensitivity. This might be a clinically applicable method to stratify treatment according to molecular stem cell subtype without tissue culture and molecular analysis.

Influence of Glucose on Candida albicans and the Relevance of the Complement FH-Binding Molecule Hgt1 in a Murine Model of Candidiasis

Candidiasis is common in diabetic patients. Complement evasion is facilitated by binding complement factor H (FH). Since the expression of high-affinity glucose transporter 1 (Hgt1), a FH-binding molecule, is glucose-dependent, we aimed to study its relevance to the pathogenesis of Candida albicans. Euglycemic and diabetic mice were intravenously challenged with either Candida albicans lacking Hgt1 (hgt1-/-) or its parental strain (SN152). Survival and clinical status were monitored over 14 days. In vitro, Candida albicans strains were grown at different glucose concentrations, opsonized with human serum, and checked for C3b/iC3b and FH deposition. Phagocytosis was studied by fluorescein isothiocyanate-labeled opsonized yeast cells incubated with granulocytes. The murine model demonstrated a significantly higher virulence of SN152 in diabetic mice and an overall increased lethality of mice challenged with hgt1-/-. In vitro lower phagocytosis and C3b/iC3b deposition and higher FH deposition were demonstrated for SN152 incubated at higher glucose concentrations, while there was no difference on hgt1-/- at physiological glucose concentrations. Despite C3b/iC3b and FH deposition being glucose-dependent, this effect has a minor influence on phagocytosis. The absence of Hgt1 is diminishing this dependency on complement deposition, but it cannot be attributed to being beneficial in a murine model.

Triangle Singularity as the Origin of the a_{1}(1420)

The COMPASS Collaboration experiment recently discovered a new isovector resonancelike signal with axial-vector quantum numbers, the a_{1}(1420), decaying to f_{0}(980)π. With a mass too close to and a width smaller than the axial-vector ground state a_{1}(1260), it was immediately interpreted as a new light exotic meson, similar to the X, Y, Z states in the hidden-charm sector. We show that a resonancelike signal fully matching the experimental data is produced by the decay of the a_{1}(1260) resonance into K^{*}(→Kπ)K[over ¯] and subsequent rescattering through a triangle singularity into the coupled f_{0}(980)π channel. The amplitude for this process is calculated using a new approach based on dispersion relations. The triangle-singularity model is fitted to the partial-wave data of the COMPASS experiment. Despite having fewer parameters, this fit shows a slightly better quality than the one using a resonance hypothesis and thus eliminates the need for an additional resonance in order to describe the data. We thereby demonstrate for the first time in the light-meson sector that a resonancelike structure in the experimental data can be described by rescattering through a triangle singularity, providing evidence for a genuine three-body effect.

Genomic and Phenotypic Analysis of Linezolid-Resistant Staphylococcus epidermidis in a Tertiary Hospital in Innsbruck, Austria

Whole genome sequencing is a useful tool to monitor the spread of resistance mechanisms in bacteria. In this retrospective study, we investigated genetic resistance mechanisms, sequence types (ST) and respective phenotypes of linezolid-resistant Staphylococcus epidermidis (LRSE, n = 129) recovered from a cohort of patients receiving or not receiving linezolid within a tertiary hospital in Innsbruck, Austria. Hereby, the point mutation G2603U in the 23S rRNA (n = 91) was the major resistance mechanism followed by the presence of plasmid-derived cfr (n = 30). The majority of LRSE isolates were ST2 strains, followed by ST5. LRSE isolates expressed a high resistance level to linezolid with a minimal inhibitory concentration of ≥256 mg/L (n = 83) in most isolates, particularly in strains carrying the cfr gene (p < 0.001). Linezolid usage was the most prominent (but not the only) trigger for the development of linezolid resistance. However, administration of linezolid was not associated with a specific resistance mechanism. Restriction of linezolid usage and the monitoring of plasmid-derived cfr in LRSE are potential key steps to reduce linezolid resistance and its transmission to more pathogenic Gram-positive bacteria.

Comparison of novel approaches for expedited pathogen identification and antimicrobial susceptibility testing against routine blood culture diagnostics

Blood stream infections pose a major challenge for clinicians as the immediate application of an appropriate antibiotic treatment is the vital factor to safe the patients' lives. This preliminary study compares three different systems promising fast pathogen identification and susceptibility testing in comparison to conventional blood culture (BC): (i) the rapid antimicrobial susceptibility testing protocol according to EUCAST in combination with the Sepsityper^® kit (sRAST), (ii) the direct inoculation method on the VITEK^®2 system (dVIT) and (iii) testing with the Accelerate Pheno^® system (AccPh). All methods were assessed in terms of accuracy, time to result and usability. Twenty‐three BC samples obtained from patients suffering from proven sepsis were analysed in detail. Pathogen identification was successful in 95·6, 91·3 and 91·3% in sRAST, dVIT and AccPh, respectively. Categorical agreement in antimicrobial susceptibility testing was 89·5, 96 and 96·6%, respectively. Time to result from sample entry to reporting ranged from an average of 4·6 h for sRAST and 6·9 h for AccPh to 10·6 h for dVIT. These results imply a significant shortening of reporting times at considerably high agreement rates for these new diagnostic approaches.

[Establishment of key indicators and limit values for assessment of claw health of cattle in Switzerland]

INTRODUCTION

Herd medicine is a field of buiatrics characterized by regular and systematic visits by the veterinarian to improve the health and performance of the animals, the quality of animal products and finally the satisfaction of the farm staff. Internationally established key indicators, such as age at first calving, heat recognition rate or the percentage of cows with clinical mastitis per month (%),26 have been available for a long time in the areas of fertility and udder health. These key indicators help veterinarians to recognize and define health problems at herd level at an early stage and to work out measures for their improvement. Such key indicators are currently lacking in the field of claw health, hence making standardized identification of problem farms considerably more difficult. Considering the permanent negative influence of claw health problems on fertility, performance and overall animal welfare, it becomes clear how valuable claw health indicators will be in the future. The aim of this study was, therefore, to develop both primary and secondary indicators of claw health and to define corresponding limit values for Switzerland. Based on a literature search, several primary and secondary indicators were developed (1˚K: Herd problem Yes/No, 2˚K: Classification of the problem). These were discussed in an expert panel consisting of practicing veterinarians, staff of the Swiss bovine herd health service and university professors with regard to their possible practical implementation and relevance. Finally, 3 primary and 10 secondary indicators were judged to be suitable to assess a herd with regard to claw health. The primary key indicators were: proportion of cows leaving the herd due to a claw problem, proportion of lame cows of a herd, and proportion of cattle with at least one claw disease. The corresponding provisional limit values (exceeding the value = problem) for Switzerland were worked out by means of surveys among farmers, hoof trimmers, veterinary students and veterinarians. In addition, recommendations from the literature and current prevalence studies were used to adapt the defined limit values to the situation on Swiss farms. In the coming years, the claw health project «Gesunde Klauen - das Fundament für die Zukunft» will collect current prevalence values of claw diseases, and the limit values will then be adjusted and specified accordingly.

A high leukocyte count and administration of hydrocortisone hamper PCR-based diagnostics for bloodstream infections

Bloodstream infections (BSIs) require an accurate and fast identification of causative pathogens. Molecular diagnostics, in particular polymerase chain reaction (PCR)-based approaches for BSI diagnostics directly from whole blood, suffer from limitations such as inhibition leading to invalid results. In this retrospective study, we analyzed 23 parameters for their potential interference with LightCycler SeptiFast PCR tests (n = 2167) routinely performed at our institution. The overall inhibition rate was 9.1%. Test date, type of ward, procalcitonin levels, high leukocyte counts, and absolute neutrophil count were significantly associated with inhibition. For a subset (n = 448), cut-off values for leukocyte counts of < 5700 cells/μL and ≥ 26,900 cells/μL were significantly associated with a low (5%) and high (67%) inhibition risk. For patients with a moderate to high leukocyte count (5700-26,900 cells/μL), the additional administration of hydrocortisone significantly increased the inhibition risk. Furthermore, freezing of blood samples prior to DNA extraction and SF testing appeared to neutralize inhibitory factors. It remains to be investigated whether other molecular diagnostic tests are susceptible to similar inhibiting parameters.

[Improvement of claw health of cattle in Switzerland]

INTRODUCTION

The modern technique of cattle hoof care was founded by E. Toussaint Raven in 1977. Environmental risk factors on cattle claws altered in the past 43 years. The change from free ranging to indoor housing, the intensified feeding and the breeding towards traits of high performance have significantly increased the mechanical and chemical stress on the claws. In modern free-stalls, dairy cows are required to walk on hard flooring to feed, drink and get milked. Good hoof health is a basic requirement for cattle welfare. Professional and regular hoof trimming is still considered the most effective measure to promote hoof health in dairy cattle. In order to meet today's requirements and to promote claw health, the Swiss Hoof Trimmers Association (SKV), in collaboration with the Vetsuisse faculties, Universities of Berne and Zurich, and the Bovine Health Service (RGD, Bern) developed and described the Swiss technique of functional claw trimming. The aim was to establish a consistent method, which takes into account the size and bodyweight of the modern cow, the anatomical and physiological characteristics of their claws and includes adaptations counteracting very relevant diseases such as digital dermatitis. The result is a workflow described and illustrated with coloured pictures and consisting of five individual steps based on the technique of E. Toussaint Raven, Additionally, the upcoming Swiss national resource project on long-term improvement of claw health is presented in some detail. The key point of this project is the electronic documentation of clinical findings by the trained professional claw trimmers. This data will later (i) be used to assess the foot health of Swiss cows, (ii) allow to determine the prevalence of foot diseases of cattle in Switzerland and (iii) to monitor the effect of the implementation of foot health concepts. The aim of this work is to combine the findings from science and the practical experience of hoof trimmers in one method, to standardize the applied hoof care in Switzerland and to adapt it to today's hoof health requirements.

Investigating the antibacterial activity of salen/salophene metal complexes: Induction of ferroptosis as part of the mode of action

The continuous increase of resistant bacteria including Staphylococcus aureus and its methicillin-resistant phenotype (MRSA) is currently one of the major challenges in medicine. Therefore, the discovery of novel lead structures for the design of drugs to fight against infections caused by these bacteria is urgently needed. In this structure-activity relationship study, metal-based drugs were investigated for the treatment of resistant pathogens. The selected Ni(II), Cu(II), Zn(II), Mn(III), and Fe(II/III) complexes differ in their salen- and salophene-type Schiff base ligands. The in vitro activity was evaluated using gram-positive (S. aureus and MRSA) and gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Especially the iron(III) complexes displayed promising antimicrobial effects against gram-positive bacteria, with MIC₉₀ values ranging from 0.781 to 50 μg/mL. Among them, chlorido[(N,N'-bis(salicylidene)-1,2-phenylenediamine]iron(III) (6) showed the best MIC₉₀ value (0.781 μg/mL = 1.93 μmol/L) against S. aureus and MRSA. Complex 6 was comparably potent as ciprofloxacin against S. aureus (0.391 μg/mL = 1.18 μmol/L) and only marginally less active than tetracycline against MRSA (0.391 μg/mL = 0.88 μmol/L). As part of the mode of action, ferroptosis was identified. Applying compound 6 (10 μg/mL), both gram-positive strains grown in PBS were killed within 20 min. This efficacy basically documents that salophene iron(III) complexes represent possible lead structures for the further development of antibacterial metal complexes.

The correct blood volume for paediatric blood cultures: a conundrum?

BACKGROUND

Bloodstream infections (BSIs) are a major cause of morbidity and mortality in paediatric patients. For fast and accurate diagnosis, blood culture (BC) is the reference standard. However, the procedure for blood sampling in paediatric patients, particularly the optimal blood volume, is the subject of controversy stemming from a lack of knowledge of the bacterial load and because of several obstacles such as low intravascular volume and the risk of causing anaemia.

AIMS

The aim of this narrative review is to summarize current knowledge on blood sampling in paediatric patients for BC purposes, in particular blood volume and number and type of BC bottles needed for reasonable future guidelines/recommendations.

SOURCES

A comprehensive literature search of PubMed, including all publications in English, was performed in June 2019 using the search terms 'blood culture', 'blood volume', 'bloodstream infection', 'diagnostic', 'paediatric' and/or 'sepsis'.

CONTENT

The amount of inoculated blood determines the sensitivity, specificity and time to positivity of a BC, and low-level bacteraemia (≤10 cfu/mL) in paediatric patients is presumed to be more common than reported. Current approaches for 'adequate' blood volume for paediatric BC are mainly weight- or age-dependent. Of these recommendations, the scheme devised by Gaur and colleagues seems most appropriate and calls for a sample of 1-1.5 mL for children weighing <11 kg and 7.5 mL for a patient weight of 11-17 kg to be drawn into one BC bottle. Inclusion of a more detailed grading in the weight range 4-14 kg, as published by Gonsalves and colleagues, might be useful.

IMPLICATIONS

This review could be important for future guidelines on paediatric BC collection and thus could contribute to improving patient management and lowering the economic and global health burden associated with BSI. Furthermore, upcoming molecular-based approaches with low sample volumes might be an interesting alternative.

Correction: Interleukin-22-deficiency and microbiota contribute to the exacerbation of Toxoplasma gondii-induced intestinal inflammation

The original version of this Article omitted the author Dr Mathias Chamaillard from the l'Institut de Pasteur, Lille, France. This has been corrected in both the PDF and HTML versions of the Article.

Interleukin-22-deficiency and microbiota contribute to the exacerbation of Toxoplasma gondii-induced intestinal inflammation

Upon oral infection with Toxoplasma gondii cysts (76 K strain) tachyzoites are released into the intestinal lumen and cross the epithelial barrier causing damage and acute intestinal inflammation in C57BL/6 (B6) mice. Here we investigated the role of microbiota and IL-22 in T.gondii-induced small intestinal inflammation. Oral T.gondii infection in B6 mice causes inflammation with IFNγ and IL-22 production. In IL-22-deficient mice, T.gondii infection augments the Th1 driven inflammation. Deficiency in either IL-22bp, the soluble IL-22 receptor or Reg3γ, an IL-22-dependent antimicrobial lectin/peptide, did not reduce inflammation. Under germ-free conditions, T.gondii-induced inflammation was reduced in correlation with parasite load. But intestinal inflammation is still present in germ-free mice, at low level, in the lamina propria, independently of IL-22 expression. Exacerbated intestinal inflammation driven by absence of IL-22 appears to be independent of IL-22 deficiency associated-dysbiosis as similar inflammation was observed after fecal transplantation of IL-22-/- or WT microbiota to germ-free-WT mice. Our results suggest cooperation between parasite and intestinal microbiota in small intestine inflammation development and endogenous IL-22 seems to exert a protective role independently of its effect on the microbiota. In conclusion, IL-22 participates in T.gondii induced acute small intestinal inflammation independently of microbiota and Reg3γ.

Neuraxial analgesia is not associated with an increased risk of post-partum relapses in MS

Background:

Obstetrical analgesia remains a matter of controversy because of the fear of neurotoxicity of local anesthetics on demyelinated fibers or their potential relationship with subsequent relapses.

Objective:

To assess the impact of neuraxial analgesia on the risk of relapse during the first 3 months post-partum, with a focus on women who experienced relapses during pregnancy.

Methods:

We analyzed data of women followed-up prospectively during their pregnancies and at least 3 months post-partum, collected in the Pregnancy in Multiple Sclerosis (PRIMS) and Prevention of Post-Partum Relapses with Progestin and Estradiol in Multiple Sclerosis (POPARTMUS) studies between 1992–1995 and 2005–2012, respectively. The association of neuraxial analgesia with the occurrence of a post-partum relapse was estimated by logistic regression analysis.

Results:

A total of 389 women were included, 215 from PRIMS and 174 from POPARTMUS. In total, 156 women (40%) had neuraxial analgesia. Overall, 24% experienced a relapse during pregnancy and 25% in the 3 months post-partum. Women with a pregnancy relapse were more likely to have a post-partum relapse (odds ratio (OR) = 1.83, p = 0.02), independently of the use of neuraxial analgesia. There was no association between neuraxial analgesia and post-partum relapse (OR = 1.08, p = 0.78).

Conclusion:

Neuraxial analgesia was not associated with an increased risk of post-partum relapses, whatever multiple sclerosis (MS) activity during pregnancy.

Amb a 1 isoforms: Unequal siblings with distinct immunological features

Background

Ragweed pollen represents a major allergy risk factor. Ragweed extracts contain five different isoforms of the major allergen Amb a 1. However, the immunological characteristics of Amb a 1 isoforms are not fully investigated. Here, we compared the physicochemical and immunological properties of three most important Amb a 1 isoforms.

Methods

After purification, the isoforms were physicochemically characterized, tested for antibody binding and induction of human T‐cell proliferative responses. Their immunological properties were further evaluated in vitro and in vivo in a mouse model.

Results

Amb a 1 isoforms exhibited distinct patterns of IgE binding and immunogenicity. Compared to Amb a 1.02 or 03 isoforms, Amb a 1.01 showed higher IgE‐binding activity. Isoforms 01 and 03 were the most potent stimulators of patients’ T cells. In a mouse model of immunization, Amb a 1.01 induced higher levels of IgG and IgE antibodies when compared to isoforms 02 and 03. Interestingly, ragweed‐sensitized patients also displayed an IgG response to Amb a 1 isoforms. However, unlike therapy‐induced antibodies, sensitization‐induced IgG did not show IgE‐blocking activity.

Conclusion

The present study showed that naturally occurring isoforms of Amb a 1 possess different immunogenic and sensitizing properties. These findings should be considered when selecting sequences for molecule‐based diagnosis and therapy for ragweed allergy. Due to its high IgE‐binding activity, isoform Amb a 1.01 should be included in diagnostic tests. In contrast, due to their limited B‐ and T‐cell cross‐reactivity patterns, a combination of different isoforms might be a more attractive strategy for ragweed immunotherapy.

First Measurement of Transverse-Spin-Dependent Azimuthal Asymmetries in the Drell-Yan Process

The first measurement of transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan (DY) process is reported. We use the CERN SPS 190  GeV/c π^{-} beam and a transversely polarized ammonia target. Three azimuthal asymmetries giving access to different transverse-momentum-dependent (TMD) parton distribution functions (PDFs) are extracted using dimuon events with invariant mass between 4.3  GeV/c^{2} and 8.5  GeV/c^{2}. Within the experimental uncertainties, the observed sign of the Sivers asymmetry is found to be consistent with the fundamental prediction of quantum chromodynamics (QCD) that the Sivers TMD PDFs extracted from DY have a sign opposite to the one extracted from semi-inclusive deep-inelastic scattering (SIDIS) data. We present two other asymmetries originating from the pion Boer-Mulders TMD PDFs convoluted with either the nucleon transversity or pretzelosity TMD PDFs. A recent COMPASS SIDIS measurement was obtained at a hard scale comparable to that of these DY results. This opens the way for possible tests of fundamental QCD universality predictions.

Analysis of 2D NMR relaxation data using Chisholm approximations

To analyze 2D NMR relaxation data based on a discrete delta-like relaxation map we extended the Padé-Laplace method to two dimensions. We approximate the forward Laplace image of the time domain signal by a Chisholm approximation, i.e. a rational polynomial in two dimensions. The poles and residues of this approximation correspond to the relaxation rates and weighting factors of the underlying relaxation map. In this work we explain the principle ideas of our algorithm and demonstrate its applicability. Therefore we compare the inversion results of the Chisholm approximation and Tikhonov regularization method as a function of SNR when the investigated signal is based on a given discrete relaxation map. Our algorithm proved to be reliable for SNRs larger than 50 and is able to compete with the Tikhonov regularization method. Furthermore we show that our method is also able to detect the simulated relaxation compartments of narrow Gaussian distributions with widths less or equal than 0.05s^-1. Finally we investigate the resolution limit with experimental data. For a SNR of 750 the Chisholm approximation method was able to resolve two relaxation compartments in 8 of 10 cases when both compartments differ by a factor of 1.7.

Ultrastructural and functional adaptations of the female reproductive system in the family Heterozerconidae (Acari, Anactinotrichida, Gamasida, Heterozerconina) and implications for the systematic position of the group

Heterozerconidae is a poorly known, early derived mite family belonging to Heterozerconina (Monogynaspida, Gamasida (= Mesostigmata)). The systematic position of the family is still controversial and little is known about the biology and anatomy of the taxon. In this paper, the gross anatomy, ultrastructure and functional morphology of the female reproductive system are described comparing genera from different geographic areas. The occurence of podospermy (i.e. the use of a sperm transfer process carried by the fixed digit of the male chelicerae to inseminate females through secondary insemination pores instead of through the oviporus) as insemination mode in this family was documented. Nevertheless, morphological and functional evidence in the reproductive system of the females supports the idea that, in the same family, more than one insemination mode is present: some genera are plesiomorphically tocospemic (i.e. insemination through the oviporus) while others switched to podospermy. Such discovery is of fundamental importance for the determination of the relationship between the family Heterozerconidae and the family Discozerconidae, both belonging tentatively to Heterozerconina and for the phylogenetic position of the Heterozerconina among Gamasida.

Observation of a New Narrow Axial-Vector Meson a1(1420)

The COMPASS Collaboration at CERN has measured diffractive dissociation of 190  GeV/c pions into the π(-)π(-)π(+) final state using a stationary hydrogen target. A partial-wave analysis (PWA) was performed in bins of 3π mass and four-momentum transfer using the isobar model and the so far largest PWA model consisting of 88 waves. A narrow peak is observed in the f0(980)π channel with spin, parity and C-parity quantum numbers J(PC)=1(++). We present a resonance-model study of a subset of the spin-density matrix selecting 3π states with J(PC)=2(++) and 4(++) decaying into ρ(770)π and with J(PC)=1(++) decaying into f0(980)π. We identify a new a1 meson with mass (1414(-13)(+15))  MeV/c2 and width (153(-23)(+8))  MeV/c2. Within the final states investigated in our analysis, we observe the new a1(1420) decaying only into f0(980)π, suggesting its exotic nature.

A general number-to-space mapping deficit in developmental dyscalculia

Previous research on developmental dyscalculia (DD) suggested that deficits in the number line estimation task are related to a failure to represent number magnitude linearly. This conclusion was derived from the observation of logarithmically shaped estimation patterns. However, recent research questioned this idea of an isomorphic relationship between estimation patterns and number magnitude representation. In the present study, we evaluated an alternative hypothesis: impairments in the number line estimation task are due to a general deficit in mapping numbers onto space. Adults with DD and a matched control group had to learn linear and non-linear layouts of the number line via feedback. Afterwards, we assessed their performance how well they learnt the new number-space mappings. We found irrespective of the layouts worse performance of adults with DD. Additionally, in case of the linear layout, we observed that their performance did not differ from controls near reference points, but that differences between groups increased as the distance to reference point increased. We conclude that worse performance of adults with DD in the number line task might be due a deficit in mapping numbers onto space which can be partly overcome relying on reference points.

Mild hypothermia induces incomplete left ventricular relaxation despite spontaneous bradycardia in pigs

AIM

Mild hypothermia (MH) decreases left ventricular (LV) end-diastolic capacitance. We sought to clarify whether this results from incomplete relaxation.

METHODS

Ten anaesthetized pigs were cooled from normothermia (NT, 38 °C) to MH (33 °C). LV end-diastolic pressure (LVPed), volume (LVVed) and pressure-volume relationships (EDPVRs) were determined during stepwise right atrial pacing. LV capacitance (i.e. LVVed at LVPed of 10 mmHg, LV VPed10) was derived from the EDPVR. Pacing-induced changes of diastolic indices (LVPed, LVVed and LV VPed10) were analysed as a function of (i) heart rate and (ii) the ratio between diastolic time interval (t-dia) and LV isovolumic relaxation constant τ, which was calculated using a logistic fit (τL ) and monoexponential fit with zero asymptote (τZ ) and nonzero asymptote (τNZ ).

RESULTS

Mild hypothermia decreased heart rate (85 ± 4 to 68 ± 3 bpm), increased τL (22 ± 1 to 57 ± 4 ms), τZ (26 ± 2 to 56 ± 5 ms) and τNZ (41 ± 1 to 96 ± 5 ms), decreased t-dia/τ ratios, and shifted the EDPVR leftwards compared to NT (all P < 0.05). During NT, pacing at ≥140 bpm shifted the EDPVR progressively leftwards. During MH, relationships between diastolic indices and heart rate were shifted towards lower heart rates compared to NT. However, relationships between diastolic indices and t-dia/τ during NT and MH were superimposable.

CONCLUSION

We conclude that the loss of LV end-diastolic capacitance during MH can be explained at least in part by slowed LV relaxation. MH thereby is an example of incomplete LV relaxation at a spontaneous low heart rate. Caution may be advised, when heart rate is increased in patients treated with MH.

Measurement of the charged-pion polarizability

The COMPASS collaboration at CERN has investigated pion Compton scattering, π(-)γ→π(-)γ, at center-of-mass energy below 3.5 pion masses. The process is embedded in the reaction π(-)Ni→π(-)γNi, which is initiated by 190 GeV pions impinging on a nickel target. The exchange of quasireal photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, Q(2)<0.0015  (GeV/c)(2). From a sample of 63,000 events, the pion electric polarizability is determined to be α(π)=(2.0±0.6(stat)±0.7(syst))×10(-4)  fm(3) under the assumption α(π)=-β(π), which relates the electric and magnetic dipole polarizabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is found in agreement with the expectation from chiral perturbation theory. An additional measurement replacing pions by muons, for which the cross-section behavior is unambiguously known, was performed for an independent estimate of the systematic uncertainty.

Effects of dark chocolate consumption on the prothrombotic response to acute psychosocial stress in healthy men

Flavanoid-rich dark chocolate consumption benefits cardiovascular health, but underlying mechanisms are elusive. We investigated the acute effect of dark chocolate on the reactivity of prothrombotic measures to psychosocial stress. Healthy men aged 20-50 years (mean ± SD: 35.7 ± 8.8) were assigned to a single serving of either 50 g of flavonoid-rich dark chocolate (n=31) or 50 g of optically identical flavonoid-free placebo chocolate (n=34). Two hours after chocolate consumption, both groups underwent an acute standardised psychosocial stress task combining public speaking and mental arithmetic. We determined plasma levels of four stress-responsive prothrombotic measures (i. e., fibrinogen, clotting factor VIII activity, von Willebrand Factor antigen, fibrin D-dimer) prior to chocolate consumption, immediately before and after stress, and at 10 minutes and 20 minutes after stress cessation. We also measured the flavonoid epicatechin, and the catecholamines epinephrine and norepinephrine in plasma. The dark chocolate group showed a significantly attenuated stress reactivity of the hypercoagulability marker D-dimer (F=3.87, p=0.017) relative to the placebo chocolate group. Moreover, the blunted D-dimer stress reactivity related to higher plasma levels of the flavonoid epicatechin assessed before stress (F=3.32, p = 0.031) but not to stress-induced changes in catecholamines (p's=0.35). There were no significant group differences in the other coagulation measures (p's≥0.87). Adjustments for covariates did not alter these findings. In conclusion, our findings indicate that a single consumption of flavonoid-rich dark chocolate blunted the acute prothrombotic response to psychosocial stress, thereby perhaps mitigating the risk of acute coronary syndromes triggered by emotional stress.