Clinical use of cone-beam computed tomography in Western Norway: a referral-based retrospective study.

OBJECTIVE: To elucidate cone-beam computed tomography (CBCT) referral profiles in Western Norway. MATERIALS AND METHODS: In all, 3,031 referrals to oral- and maxillofacial radiologist were reviewed. Patient data were retrieved retrospectively from electronic charts. The patient's age, gender, and perceived clinical indication were noted, as well as relevant medical and dental history and whether the referring clinician was a general dentist or held a clinical dental specialty. RESULTS: A total of 2,680 referrals fulfilled the inclusion criteria (UiB n = 1,471, and TkVestland, n = 1,209). The female:male ratio was 1,427:1,253. Mean age was 33 years - 35 years for females compared to 31 years for males (p < 0.001). The most common clinical indications were related to impacted teeth (29%), endodontic issues (17%), cleft lip palate (12%), and resorptions (10%). Less common were bone lesions, implant planning, trauma to the teeth or jaws, atypical orofacial pain, and temporo-mandibular joint (TMJ). The patient age-profiles mirrored differences in indications within the cohort. Most referrals were from specialist dentists such as orthodontists, oral surgeons, and endodontists. Interestingly, 543/2,680 (20%) referrals were from general dentists.  Conclusions: Specialist dentists such as orthodontists, oral surgeons, and endodontists refer most patients for clinical indications such as impacted teeth, endodontic issues, and resorptions.

Cooperative folding as a molecular switch in an evolved antibody binder.

Designing proteins with tunable activities from easily accessible external cues remains a biotechnological challenge. Here, we set out to create a small antibody-binding domain equipped with a molecular switch inspired by the allosteric response to calcium seen in naturally derived proteins like calmodulin. We have focused on one of the three domains of Protein G that show inherent affinity to antibodies. By combining a semi-rational protein design with directed evolution, we engineered novel variants containing a calcium-binding loop rendering the inherent antibody affinity calcium-dependent. The evolved variants resulted from a designed selection strategy subjecting them to negative and positive selection pressures focused on conditional antibody binding. Hence, these variants contains molecular "on/off" switches, controlling the target affinity towards antibody fragments simply by the presence or absence of calcium. From NMR spectroscopy we found that the molecular mechanism underlying the evolved switching behavior was a coupled calcium-binding and folding event where the target binding surface was intact and functional only in the presence of bound calcium. Notably, it was observed that the response to the employed selection pressures gave rise to the evolution of a cooperative folding mechanism. This observation illustrates why the cooperative folding reaction is an effective solution seen repeatedly in the natural evolution of fine-tuned macromolecular recognition. Engineering binding moieties to confer conditional target interaction has great potential due to the exquisite interaction control that is tunable to application requirements. Improved understanding of the molecular mechanisms behind regulated interactions is crucial to unlock how to engineer switchable proteins useful in a variety of biotechnological applications.

Reliability Exercise of Ultrasound Salivary Glands in Sjögren's Disease: An International Web Training Initiative.

INTRODUCTION: Major salivary gland ultrasonography (SGUS) demonstrated its good metric properties as an outcome measure for diagnosing primary Sjögren's disease (SD). The objective was to assess SGUS reliability among sonographers with different levels of experience, using web training. METHODS: Sonographers from expert centers participated in the reliability exercise. Before exercises, training was done by videoconferencing. Reliability of the two most experienced sonographers (MES) was assessed and then compared to other sonographers. Intra-reader and inter-reader reliability of SGUS items were assessed by computing Cohen's κ coefficients. RESULTS: All sets were read twice by all 14 sonographers within a 4-month interval. Intra-reader reliability of MES was almost perfect for homogeneity, substantial for Outcome Measures in Rheumatology (OMERACT) scoring system (OMERACTss). Among LES (less experienced sonographers), reliability was moderate to almost perfect for homogeneity, fair to moderate for OMERACTss, and fair to almost perfect for binary OMERACTss. Inter-reader reliability between MES was almost perfect for homogeneity, substantial for diagnosis, moderate for OMERACTss, and substantial for binary OMERACTss. Compared to MES, reliabilities of LES were moderate to almost perfect for both homogeneity and diagnosis, only fair to moderate for OMERACTss, but increased in binary OMERACTss. CONCLUSIONS: Videoconferencing training sessions in an international reliability exercise could be an excellent tool to train experienced and less-experienced sonographers. SGUS homogeneity items is useful to distinguish normal from abnormal salivary glands parenchyma independently of diagnosis. Structural damage evaluations by OMERACT scoring system is a new comprehensive score to diagnose patients with SD and could be easily used by sonographers in a binary method.

The goal of this project was to evaluate the reliability of salivary gland ultrasonography in patients with Sjögren's disease using online training in an international study. Currently, salivary gland ultrasonography is routinely used only by European expert sonographers but few studies have studied intra-reader and inter-reader reliability, among less experienced international sonographers. Many salivary gland ultrasonography scoring systems are used today, but it is difficult to know how to put them into practice. Online training on an international level allows a significant number of practitioners to use the different scoring systems including the latest OMERACT (Outcome Measures in Rheumatology) score, which is simple and comprehensive. There were two phases to this project: A first step consisted in a training session by videoconferencing to all sonographers, the second step was an inter and intra-reader reliability exercises. The results of our study showed satisfactory results, especially for parenchyma homogeneity. Regarding the comprehensive OMERACT score, the results are quite disparate, notably for less experienced sonographers and could be explained by this new comprehensive scoring system. However, when binary OMERACT score (minor damage versus major damage of salivary gland parenchyma (OMERACT score 0­1 vs. 2­3) was employed, reliability increased and can be very useful for novice sonographers in routine practice because it does not require scoring of all the pathological features in Sjögren's disease. This study highlights the need to train non-experts interested in this field and demonstrates the potential for beginners to quickly become experts.

An easy-to-use high-throughput selection system for the discovery of recombinant protein binders from alternative scaffold libraries.

Selection by phage display is a popular and widely used technique for the discovery of recombinant protein binders from large protein libraries for therapeutic use. The protein library is displayed on the surface of bacteriophages which are amplified using bacteria, preferably Escherichia coli, to enrich binders in several selection rounds. Traditionally, the so-called panning procedure during which the phages are incubated with the target protein, washed and eluted is done manually, limiting the throughput. High-throughput systems with automated panning already in use often require high-priced equipment. Moreover, the bottleneck of the selection process is usually the screening and characterization. Therefore, having a high-throughput panning procedure without a scaled screening platform does not necessarily increase the discovery rate. Here, we present an easy-to-use high-throughput selection system with automated panning using cost-efficient equipment integrated into a workflow with high-throughput sequencing and a tailored screening step using biolayer-interferometry. The workflow has been developed for selections using two recombinant libraries, ADAPT (Albumin-binding domain-derived affinity proteins) and CaRA (Calcium-regulated affinity) and has been evaluated for three new targets. The newly established semi-automated system drastically reduced the hands-on time and increased robustness while the selection outcome, when compared to manual handling, was very similar in deep sequencing analysis and generated binders in the nanomolar affinity range. The developed selection system has shown to be highly versatile and has the potential to be applied to other binding domains for the discovery of new protein binders.

Variants in the DDX6-CXCR5 autoimmune disease risk locus influence the regulatory network in immune cells and salivary gland.

Fine mapping and bioinformatic analysis of the DDX6-CXCR5 genetic risk association in Sjögren's Disease (SjD) and Systemic Lupus Erythematosus (SLE) identified five common SNPs with functional evidence in immune cell types: rs4938573, rs57494551, rs4938572, rs4936443, rs7117261. Functional interrogation of nuclear protein binding affinity, enhancer/promoter regulatory activity, and chromatin-chromatin interactions in immune, salivary gland epithelial, and kidney epithelial cells revealed cell type-specific allelic effects for all five SNPs that expanded regulation beyond effects on DDX6 and CXCR5 expression. Mapping the local chromatin regulatory network revealed several additional genes of interest, including lnc-PHLDB1-1. Collectively, functional characterization implicated the risk alleles of these SNPs as modulators of promoter and/or enhancer activities that regulate cell type-specific expression of DDX6, CXCR5, and lnc-PHLDB1-1, among others. Further, these findings emphasize the importance of exploring the functional significance of SNPs in the context of complex chromatin architecture in disease-relevant cell types and tissues.

CaRA - A multi-purpose phage display library for selection of calcium-regulated affinity proteins.

Protein activity regulated by interactions with metal ions can be utilized for many different purposes, including biological therapies and bioprocessing, among others. Calcium ions are known to interact with the frequently occurring EF-hand motif, which can alter protein activity upon binding through an induced conformational change. The calcium-binding loop of the EF-hand motif has previously been introduced into a small protein domain derived from staphylococcal Protein A in a successful effort to render antibody binding dependent on calcium. Presented here, is a combinatorial library for calcium-regulated affinity, CaRA, based on this domain. CaRA is the first alternative scaffold library designed to achieve novel target specificities with metal-dependent binding. From this library, several calcium-dependent binders could be isolated through phage display campaigns towards a set of unrelated target proteins (IgE Cε3-Cε4, TNFα, IL23, scFv, tPA, PCSK9 and HER3) useful for distinct applications. Overall, these monomeric CaRA variants showed high stability and target affinities within the nanomolar range. They displayed considerably higher melting temperatures in the presence of 1 mM calcium compared to without calcium. Further, all discovered binders proved to be calcium-dependent, with the great majority showing complete lack of target binding in the absence of calcium. As demonstrated, the CaRA library is highly capable of providing protein-binding domains with calcium-dependent behavior, independent of the type of target protein. These binding domains could subsequently be of great use in gentle protein purification or as novel therapeutic modalities.

A One Health real-time surveillance system for nowcasting Campylobacter gastrointestinal illness outbreaks, Norway, week 30 2010 to week 11 2022.

BackgroundCampylobacter is a leading cause of food and waterborne illness. Monitoring and modelling Campylobacter at chicken broiler farms, combined with weather pattern surveillance, can aid nowcasting of human gastrointestinal (GI) illness outbreaks. Near real-time sharing of data and model results with health authorities can help increase potential outbreak responsiveness.AimsTo leverage data on weather and Campylobacter on broiler farms to build a risk model for possible human Campylobacter outbreaks and to communicate risk assessments with health authorities.MethodsWe developed a spatio-temporal random effects model for weekly GI illness consultations in Norwegian municipalities with Campylobacter monitoring and weather data from week 30 2010 to 11 2022 to give 1-week nowcasts of GI illness outbreaks. The approach combined a municipality random effects baseline model for seasonally-adjusted GI illness with a second model for peak deviations from that baseline. Model results are communicated to national and local stakeholders through an interactive website: Sykdomspulsen One Health.ResultsLagged temperature and precipitation covariates, as well as 2-week-lagged positive Campylobacter sampling in broilers, were associated with higher levels of GI consultations. Significant inter-municipality variability in outbreak nowcasts were observed.ConclusionsCampylobacter surveillance in broilers can be useful in GI illness outbreak nowcasting. Surveillance of Campylobacter along potential pathways from the environment to illness such as via water system monitoring may improve nowcasting. A One Health system that communicates near real-time surveillance data and nowcast changes in risk to health professionals facilitates the prevention of Campylobacter outbreaks and reduces impact on human health.

Genome-wide association study identifies Sjögren's risk loci with functional implications in immune and glandular cells.

Sjögren's disease is a complex autoimmune disease with twelve established susceptibility loci. This genome-wide association study (GWAS) identifies ten novel genome-wide significant (GWS) regions in Sjögren's cases of European ancestry: CD247, NAB1, PTTG1-MIR146A, PRDM1-ATG5, TNFAIP3, XKR6, MAPT-CRHR1, RPTOR-CHMP6-BAIAP6, TYK2, SYNGR1. Polygenic risk scores yield predictability (AUROC = 0.71) and relative risk of 12.08. Interrogation of bioinformatics databases refine the associations, define local regulatory networks of GWS SNPs from the 95% credible set, and expand the implicated gene list to >40. Many GWS SNPs are eQTLs for genes within topologically associated domains in immune cells and/or eQTLs in the main target tissue, salivary glands.

High sequence similarity between avian pathogenic E. coli isolates from individual birds and within broiler chicken flocks during colibacillosis outbreaks.

Avian pathogenic E. coli (APEC) cause high first week mortality (FWM) in broiler chickens worldwide. In order to investigate the epidemiologic aspects of colibacillosis in broiler flocks it is important to develop reliable and cost-effective sampling guidelines. In this context, it is particularly important to define the minimum number of samples required to reliably identify the causative APEC clone during outbreaks of colibacillosis. This study describes the diversity of E. coli isolates between and within three flocks with high FWM due to colibacillosis. Each flock was represented by five animals, showing typical lesions of colibacillosis, and spleen, liver and one other organ from each animal was sampled for APEC. A total of 47 E. coli isolates, one per organ, and approximately 15 isolates per flock were whole genome sequenced and compared by multilocus sequence typing (MLST), serotyping and phylogenetic analysis to deduce their relationship. The results revealed that within individual birds there was little or no sequence type (ST) or serotype diversity between APEC isolates from different organs. Based on phylogenetic analysis, isolates belonging to the same ST and serotype showed a low number of single nucleotide polymorphisms (SNPs) across more than 95 % of the genome. Isolates from the liver always represented the major disease-causing APEC in individual birds, even when more than one ST was detected within an individual bird and flock. This study guides us towards an economically efficient way of sampling for future epidemiological studies on colibacillosis, by determining the causative APEC-clone at flock level.

Radiographic features in 2D imaging as predictors for justified CBCT examinations of canine-induced root resorption.

OBJECTIVES: This retrospective observational study aimed to evaluate the diagnostic accuracy of two-dimensional radiographs on canine-induced root resorption (CIRR) in lateral incisors and identify predictors of CIRR in patients with impacted maxillary canines (IMC). METHODS: Ninety-nine patients aged 9-17 years, with 156 IMCs, were included in the study. All had CBCT-volumes and two-dimensional radiographs consisting of at least one panoramic radiograph. Two radiologists jointly viewed all cases twice. First, radiographic features related to the IMC and possible CIRR were recorded from two-dimensional radiographs. Then, CIRR was determined from CBCT and according to position and extension classified as mild, moderate and severe. RESULTS: CIRRs was detected in 80% of lateral incisors (mild: 45%; moderate: 44%; severe: 11%). The sensitivity was generally low at mild and moderate cut-offs (29 and 29%), and somewhat higher for severe (50%). Corresponding specificities were 48%, 63% and 68%. Canine cusp-tip superimposing the lateral incisor's middle third and root/crown ratio >1 was positively associated with mild CIRR, with an odds ratio (OR) of 3.8 and 6.7, respectively. In addition, the root development stage was positively associated with moderate/severe CIRR when the canine root was nearly or fully developed (OR = 3.1). CONCLUSIONS: The diagnostic accuracy of two-dimensional radiographs was inadequate for detecting CIRR amongst patients referred for CBCT examinations. Based on our results, none of the suggested two-dimensional radiographic features could predict moderate/severe CIRR except for root development stage. IMC in a later stage of root development seems to be associated with a higher risk of moderate/severe CIRR.

A cell-free high throughput assay for assessment of SARS-CoV-2 neutralizing antibodies.

Highly accurate serological tests are key to assessing the prevalence of SARS-CoV-2 antibodies and the level of immunity in the population. This is important to predict the current and future status of the pandemic. With the recent emergence of new and more infectious SARS-CoV-2 variants, assays allowing for high throughput analysis of antibodies able to neutralize SARS-CoV-2 become even more important. Here, we report the development and validation of a robust, high throughput method, which enables the assessment of antibodies inhibiting the binding between the SARS-CoV-2 spike protein and angiotensin converting enzyme 2 (ACE2). The assay uses recombinantly produced spike-f and ACE2 and is performed in a bead array format, which allows analysis of up to 384 samples in parallel per instrument over seven hours, demanding only one hour of manual handling. The method is compared to a microneutralization assay utilising live SARS-CoV-2 and is shown to deliver highly correlating data. Further, a comparison with a serological method that measures all antibodies recognizing the spike protein shows that this type of assessment provides important insights into the neutralizing efficiency of the antibodies, especially for individuals with low antibody levels. This method can be an important and valuable tool for large-scale assessment of antibody-based neutralization, including neutralization of new spike variants that might emerge.

Inhibiting cardiac myeloperoxidase alleviates the relaxation defect in hypertrophic cardiomyocytes.

AIMS: Hypertrophic cardiomyopathy (HCM) is characterized by cardiomyocyte hypertrophy and disarray, and myocardial stiffness due to interstitial fibrosis, which result in impaired left ventricular filling and diastolic dysfunction. The latter manifests as exercise intolerance, angina, and dyspnoea. There is currently no specific treatment for improving diastolic function in HCM. Here, we investigated whether myeloperoxidase (MPO) is expressed in cardiomyocytes and provides a novel therapeutic target for alleviating diastolic dysfunction in HCM. METHODS AND RESULTS: Human cardiomyocytes derived from control-induced pluripotent stem cells (iPSC-CMs) were shown to express MPO, with MPO levels being increased in iPSC-CMs generated from two HCM patients harbouring sarcomeric mutations in the MYBPC3 and MYH7 genes. The presence of cardiomyocyte MPO was associated with higher chlorination and peroxidation activity, increased levels of 3-chlorotyrosine-modified cardiac myosin binding protein-C (MYBPC3), attenuated phosphorylation of MYBPC3 at Ser-282, perturbed calcium signalling, and impaired cardiomyocyte relaxation. Interestingly, treatment with the MPO inhibitor, AZD5904, reduced 3-chlorotyrosine-modified MYBPC3 levels, restored MYBPC3 phosphorylation, and alleviated the calcium signalling and relaxation defects. Finally, we found that MPO protein was expressed in healthy adult murine and human cardiomyocytes, and MPO levels were increased in diseased hearts with left ventricular hypertrophy. CONCLUSION: This study demonstrates that MPO inhibition alleviates the relaxation defect in hypertrophic iPSC-CMs through MYBPC3 phosphorylation. These findings highlight cardiomyocyte MPO as a novel therapeutic target for improving myocardial relaxation associated with HCM, a treatment strategy which can be readily investigated in the clinical setting, given that MPO inhibitors are already available for clinical testing.

Understanding Fatigue in Sjögren's Syndrome: Outcome Measures, Biomarkers and Possible Interventions.

Sjögren's syndrome (SS) is an autoimmune disease affecting the salivary and lacrimal glands. Symptoms range from dryness to severe extra-glandular disease involving manifestations in the skin, lungs, nervous system, and kidney. Fatigue occurs in 70% of patients, characterizing primary SS (pSS) and significantly impacting the patient's quality of life. There are some generic and specific instruments used to measure fatigue in SS. The mechanisms involved with fatigue in SS are still poorly understood, but it appears fatigue signaling pathways are more associated with cell protection and defense than with pro-inflammatory pathways. There are no established pharmacological treatment options for fatigue in pSS. So far, exercise and neuromodulation techniques have shown positive effects on fatigue in pSS. This study briefly reviews fatigue in pSS, with special attention to outcome measures, biomarkers, and possible treatment options.

Genetic and clinical basis for two distinct subtypes of primary Sjögren's syndrome.

OBJECTIVES: Clinical presentation of primary Sjögren's syndrome (pSS) varies considerably. A shortage of evidence-based objective markers hinders efficient drug development and most clinical trials have failed to reach primary endpoints. METHODS: We performed a multicentre study to identify patient subgroups based on clinical, immunological and genetic features. Targeted DNA sequencing of 1853 autoimmune-related loci was performed. After quality control, 918 patients with pSS, 1264 controls and 107 045 single nucleotide variants remained for analysis. Replication was performed in 177 patients with pSS and 7672 controls. RESULTS: We found strong signals of association with pSS in the HLA region. Principal component analysis of clinical data distinguished two patient subgroups defined by the presence of SSA/SSB antibodies. We observed an unprecedented high risk of pSS for an association in the HLA-DQA1 locus of odds ratio 6.10 (95% CI: 4.93, 7.54, P=2.2×10-62) in the SSA/SSB-positive subgroup, while absent in the antibody negative group. Three independent signals within the MHC were observed. The two most significant variants in MHC class I and II respectively, identified patients with a higher risk of hypergammaglobulinaemia, leukopenia, anaemia, purpura, major salivary gland swelling and lymphadenopathy. Replication confirmed the association with both MHC class I and II signals confined to SSA/SSB antibody positive pSS. CONCLUSION: Two subgroups of patients with pSS with distinct clinical manifestations can be defined by the presence or absence of SSA/SSB antibodies and genetic markers in the HLA locus. These subgroups should be considered in clinical follow-up, drug development and trial outcomes, for the benefit of both subgroups.

Salivary Gland Ultrasonography in Sjögren's Syndrome: A European Multicenter Reliability Exercise for the HarmonicSS Project.

Objectives: Salivary gland ultrasonography (SGUS) is increasingly applied for the management of primary Sjögren's syndrome (pSS). This study aims to: (i) compare the reliability between two SGUS scores; (ii) test the reliability among sonographers with different levels of experience. Methods: In the reliability exercise, two four-grade semi-quantitative SGUS scoring systems, namely De Vita et al. and OMERACT, were tested. The sonographers involved in work-package 7 of the HarmonicSS project from nine countries in Europe were invited to participate. Different levels of sonographers were identified on the basis of their SGUS experience and of the knowledge of the tested scores. A dedicated atlas was used as support for SGUS scoring. Results: Twenty sonographers participated in the two rounds of the reliability exercise. The intra-rater reliability for both scores was almost perfect, with a Light's kappa of 0.86 for the De Vita et al. score and 0.87 for the OMERACT score. The inter-rater reliability for the De Vita et al. and the OMERACT score was substantial with Light's Kappa of 0.75 and 0.77, respectively. Furthermore, no significant difference was noticed among sonographers with different levels of experience. Conclusion: The two tested SGUS scores are reliable for the evaluation of major salivary glands in pSS, and even less-expert sonographers could be reliable if adequately instructed.

Juvenile Sjögren's Syndrome: Clinical Characteristics With Focus on Salivary Gland Ultrasonography.

OBJECTIVE: Juvenile Sjögren's syndrome (SS) is a rare, poorly defined, and possibly underdiagnosed condition affecting children and adolescents. The aim of this study was to characterize symptoms and clinical findings of juvenile SS and to explore the clinical application of major salivary gland ultrasonography (SGUS) in patients with juvenile SS. METHODS: A cross-sectional multicenter study recruited patients with disease onset until age 18 years (n = 67). Disease characteristics were recorded, and unstimulated whole sialometry and SGUS examination of the parotid and submandibular salivary glands were performed. RESULTS: The female:male ratio was 58:9. The mean age at first symptom was 10.2 years and 12.1 years at diagnosis. Ocular and oral symptoms were noted in 42 of 67 patients (63%) and 53 of 66 patients (80%), respectively. The American-European Consensus Group or American College of Rheumatology/European League Against Rheumatism classification criteria for primary SS were fulfilled by 42 of 67 patients (63%). Pathologic SGUS findings were observed in 41 of 67 patients (61%); 26 of 41 SGUS+ patients (63%) fulfilled primary SS criteria. Salivary gland enlargements/parotitis were noted in 37 of 58 patients and were nonsignificantly associated with SGUS+ status (P = 0.066). The mean levels of saliva were 5.6 ml/15 minutes in SGUS- patients compared to 3.3 ml/15 minutes in the SGUS+ patients (P = 0.049). A total of 36 of 41 SGUS+ patients (88%) were anti-Ro/La+ compared to 14 of 26 SGUS- patients (54%) (P = 0.001). In addition, 24 of 39 SGUS+ patients (62%) were positive for rheumatoid factor (RF), whereas only 5 of 25 SGUS- patients (20%) were RF+ (P = 0.001). CONCLUSION: Juvenile SS is characterized by a large spectrum of clinical symptoms and findings. Several glandular and extraglandular parameters such as hyposalivation, swollen salivary glands, and autoantibodies are associated with pathologic SGUS findings.

Assessment of major salivary gland ultrasonography in Sjögren's syndrome. A comparison between bedside and post-examination evaluations.

OBJECTIVES: Major salivary gland ultrasonography (SGUS) is a suitable diagnostic tool in Sjögren's syndrome (SS). We aimed to determine the more representative gland, projection and format most applicable for reproducible image analysis. METHODS: One investigator performed SGUS in patients with SS. Parotid and submandibular glands were examined in longitudinal and transverse planes and evaluated bedside using a simplified scoring system (0-3). Longitudinal and transverse images and videos of all glands were stored and later evaluated/graded by three investigators, at two time-points. Agreement was calculated using intraclass correlation coefficient (ICC). RESULTS: The ICC for static image and video scoring compared to bedside evaluation ranged from 0.131 to 0.882. Average ICC for longitudinal/transverse image was 0.667/0.662, and 0.683/0.510 for longitudinal/transverse video. Interobserver reliability was good to excellent (0.81-0.94). Intraobserver reliability scores ranged from fair to excellent (0.46-0.96). The correlation between image and video evaluations of all modalities and examiners was good to excellent (0.614-0.904). The best mean ICC was found for the longitudinal projection of the left parotid gland (0.861) and the lowest mean ICC was for the transverse projection of the left submandibular gland (0.66). CONCLUSIONS: Our study indicates a trend favouring longitudinal video of the parotid gland as preferred projection, gland and storage format.

The influence of hERG1a and hERG1b isoforms on drug safety screening in iPSC-CMs.

The human Ether-à-go-go Related Gene (hERG) encodes the pore forming subunit of the channel that conducts the rapid delayed rectifier potassium current IKr. IKr drives repolarization in the heart and when IKr is dysfunctional, cardiac repolarization delays, the QT interval on the electrocardiogram (ECG) prolongs and the risk of developing lethal arrhythmias such as Torsade de Pointes (TdP) increases. TdP risk is incorporated in drug safety screening for cardiotoxicity where hERG is the main target since the IKr channels appear highly sensitive to blockage. hERG block is also included as an important read-out in the Comprehensive in Vitro Proarrhythmia Assay (CiPA) initiative which aims to combine in vitro and in silico experiments on induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) to screen for cardiotoxicity. However, the hERG channel has some unique features to consider for drug safety screening, which we will discuss in this study. The hERG channel consists of different isoforms, hERG1a and hERG1b, which individually influence the kinetics of the channel and the drug response in the human heart and in iPSC-CMs. hERG1b is often underappreciated in iPSC-CM studies, drug screening assays and in silico models, and the fact that its contribution might substantially differ between iPSC-CM and healthy but also diseased human heart, adds to this problem. In this study we show that the activation kinetics in iPSC-CMs resemble hERG1b kinetics using Cs+ as a charge carrier. Not including hERG1b in drug safety testing might underestimate the actual role of hERG1b in repolarization and drug response, and might lead to inappropriate conclusions. We stress to focus more on including hERG1b in drug safety testing concerning IKr.