ICAM-1 nanoclusters regulate hepatic epithelial cell polarity by leukocyte adhesion-independent control of apical actomyosin.

Epithelial intercellular adhesion molecule (ICAM)-1 is apically polarized, interacts with, and guides leukocytes across epithelial barriers. Polarized hepatic epithelia organize their apical membrane domain into bile canaliculi and ducts, which are not accessible to circulating immune cells but that nevertheless confine most of ICAM-1. Here, by analyzing ICAM-1_KO human hepatic cells, liver organoids from ICAM-1_KO mice and rescue-of-function experiments, we show that ICAM-1 regulates epithelial apicobasal polarity in a leukocyte adhesion-independent manner. ICAM-1 signals to an actomyosin network at the base of canalicular microvilli, thereby controlling the dynamics and size of bile canalicular-like structures. We identified the scaffolding protein EBP50/NHERF1/SLC9A3R1, which connects membrane proteins with the underlying actin cytoskeleton, in the proximity interactome of ICAM-1. EBP50 and ICAM-1 form nano-scale domains that overlap in microvilli, from which ICAM-1 regulates EBP50 nano-organization. Indeed, EBP50 expression is required for ICAM-1-mediated control of BC morphogenesis and actomyosin. Our findings indicate that ICAM-1 regulates the dynamics of epithelial apical membrane domains beyond its role as a heterotypic cell-cell adhesion molecule and reveal potential therapeutic strategies for preserving epithelial architecture during inflammatory stress.

Molecular Insights of Cholestasis in MDR2 Knockout Murine Liver Organoids.

MDR3 (multidrug resistance 3) deficiency in humans (MDR2 in mice) causes progressive familial intrahepatic cholestasis type 3 (PFIC3). PFIC3 is a lethal disease characterized by an early onset of intrahepatic cholestasis progressing to liver cirrhosis, a preneoplastic condition, putting individuals at risk of hepatocellular carcinoma (HCC). Hepatocyte-like organoids from MDR2-deficient mice (MDR2KO) were used in this work to study the molecular alterations caused by the deficiency of this transporter. Proteomic analysis by mass spectrometry allowed characterization of 279 proteins that were differentially expressed in MDR2KO compared with wild-type organoids. Functional enrichment analysis indicated alterations in three main cellular functions: (1) interaction with the extracellular matrix, (2) remodeling intermediary metabolism, and (3) cell proliferation and differentiation. The affected cellular processes were validated by orthogonal molecular biology techniques. Our results point to molecular mechanisms associated with PFIC3 that may drive the progression to liver cirrhosis and HCC and suggest proteins and cellular processes that could be targeted for the development of early detection strategies for these severe liver diseases.

Simultaneous Targeting of IL-1-Signaling and IL-6-Trans-Signaling Preserves Human Pulmonary Endothelial Barrier Function During a Cytokine Storm-Brief Report.

BACKGROUND: Systemic inflammatory diseases, such as sepsis and severe COVID-19, provoke acute respiratory distress syndrome in which the pathological hyperpermeability of the microvasculature, induced by uncontrolled inflammatory stimulation, causes pulmonary edema. Identifying the inflammatory mediators that induce human lung microvascular endothelial cell barrier dysfunction is essential to find the best anti-inflammatory treatments for critically ill acute respiratory distress syndrome patients. METHODS: We have compared the responses of primary human lung microvascular endothelial cells to the main inflammatory mediators involved in cytokine storms induced by sepsis and SARS-CoV2 pulmonary infection and to sera from healthy donors and severely ill patients with sepsis. Endothelial barrier function was measured by electric cell-substrate impedance sensing, quantitative confocal microscopy, and Western blot. RESULTS: The human lung microvascular endothelial cell barrier was completely disrupted by IL (interleukin)-6 conjugated with soluble IL-6R (IL-6 receptor) and by IL-1ß (interleukin-1beta), moderately affected by TNF (tumor necrosis factor)-α and IFN (interferon)-γ and unaffected by other cytokines and chemokines, such as IL-6, IL-8, MCP (monocyte chemoattractant protein)-1 and MCP-3. The inhibition of IL-1 and IL-6R simultaneously, but not separately, significantly reduced endothelial hyperpermeability on exposing human lung microvascular endothelial cells to a cytokine storm consisting of 8 inflammatory mediators or to sera from patients with sepsis. Simultaneous inhibition of IL-1 and JAK (Janus kinase)-STAT (signal transducer and activator of transcription protein), a signaling node downstream IL-6 and IFN-γ, also prevented septic serum-induced endothelial barrier disruption. CONCLUSIONS: These findings strongly suggest a major role for both IL-6 trans-signaling and IL-1ß signaling in the pathological increase in permeability of the human lung microvasculature and reveal combinatorial strategies that enable the gradual control of pulmonary endothelial barrier function in response to a cytokine storm.

Preclinical safety of negatively charged microspheres (NCMs): Optimization of radiolabeling for in vivo and ex vivo biodistribution studies after topical administration on full-thickness wounds in a rat model.

Negatively charged microspheres (NCMs) are postulated as a new form of treatment for chronic wounds. Despite the efficacy shown at clinical level, more studies are required to demonstrate their safety and local effect. The objective of the work was to confirm the lack of NCM systemic absorption performing a biodistribution study of the NCMs in an open wound rat animal model. To this end, radiolabeling of NCMs with technetium-99 m was optimized and biodistribution studies were performed by in vivo SPEC/CT imaging and ex vivo counting during 24 h after topical administration. The studies were performed on animals treated with a single or repeated dose to study the effect of macrophages during a prolonged treatment. NCM radiolabeling was achieved in a simple, efficient and stable manner with high yield. SPECT/CT images showed that almost all NCMs (about 85 %) remained on the wound for 24 h either after single or multiple administrations. Ex vivo biodistribution studies confirmed that there was no accumulation of NCMs in any organ or tissue except in the wound area, suggesting a lack of absorption. In conclusion, NCMs can be considered safe as local wound treatment since they remain at the administration area.

Plasmolipin regulates basolateral-to-apical transcytosis of ICAM-1 and leukocyte adhesion in polarized hepatic epithelial cells.

Apical localization of Intercellular Adhesion Receptor (ICAM)-1 regulates the adhesion and guidance of leukocytes across polarized epithelial barriers. Here, we investigate the molecular mechanisms that determine ICAM-1 localization into apical membrane domains of polarized hepatic epithelial cells, and their effect on lymphocyte-hepatic epithelial cell interaction. We had previously shown that segregation of ICAM-1 into apical membrane domains, which form bile canaliculi and bile ducts in hepatic epithelial cells, requires basolateral-to-apical transcytosis. Searching for protein machinery potentially involved in ICAM-1 polarization we found that the SNARE-associated protein plasmolipin (PLLP) is expressed in the subapical compartment of hepatic epithelial cells in vitro and in vivo. BioID analysis of ICAM-1 revealed proximal interaction between this adhesion receptor and PLLP. ICAM-1 colocalized and interacted with PLLP during the transcytosis of the receptor. PLLP gene editing and silencing increased the basolateral localization and reduced the apical confinement of ICAM-1 without affecting apicobasal polarity of hepatic epithelial cells, indicating that ICAM-1 transcytosis is specifically impaired in the absence of PLLP. Importantly, PLLP depletion was sufficient to increase T-cell adhesion to hepatic epithelial cells. Such an increase depended on the epithelial cell polarity and ICAM-1 expression, showing that the epithelial transcytotic machinery regulates the adhesion of lymphocytes to polarized epithelial cells. Our findings strongly suggest that the polarized intracellular transport of adhesion receptors constitutes a new regulatory layer of the epithelial inflammatory response.

Mechanical Properties of Lumbar and Cervical Paravertebral Muscles in Patients with Axial Spondyloarthritis: A Case-Control Study.

BACKGROUND: Axial spondyloarthritis (axSpA) affects spinal muscles, due to inflammation and structural damage. The mechanical properties of the muscles, such as tone or stiffness, could be altered in axSpA. The aim of this work is to analyze the mechanical properties of cervical and lumbar spine muscles in axSpA patients and their relationship with metrology measures, function, disease activity, structural damage and quality of life. METHODS: axSpA patients and age/gender/BMI matched healthy controls were recruited. The muscle mechanical properties (MMPs), such as tone or frequency, stiffness, decrement (linear elastic properties), relaxation and creep (viscoelastic properties), of cervical (semispinalis capitis) and lumbar (erector spinae) muscles were bilaterally measured at rest using myotonometry. Additionally, conventional metrology, BASMI (metrology index), BASDAI (disease activity index), mSASSS (radiological structural damage index) and SF-12 (health-related quality of life questionnaire) were used in the axSpA group. Between-groups comparison, intra-group correlations and multivariable regression analyses were performed to achieve the study aims. RESULTS: Thirty-four axSpA patients (mean age: 46.21 ± 8.53 y) and 34 healthy volunteers (mean age: 43.97 ± 8.49 y) were recruited. Both in cervical and lumbar spine, linear elastic parameters were significantly higher in axSpA patients in comparison with controls, while viscoelastic parameters were significantly lower. Lumbar muscle frequency, stiffness, relaxation, creep and cervical muscle elasticity were fair to strongly correlated (|0.346| < r < |0.774|) with age, functional status, activity of disease, structural damage and quality of life in axSpA patients. Furthermore, moderate to good fitted multivariate models (0.328 < R2 < 0.697) were obtained combining age, conventional metrology, activity of the disease and function for the estimation of cervical and lumbar MMPs. CONCLUSION: Mechanical properties of spinal muscles of axSpA patients differ from controls. Lumbar and cervical muscles exhibit greater linear elastic properties and lower viscoelastic properties, which are related with age, clinical and psychophysiological features of axSpA.

Patients with Axial Spondyloarthritis Show an Altered Flexion/Relaxation Phenomenon.

Axial spondyloarthritis (axSpA) is a chronic rheumatic disease characterized by the presence of inflammatory back pain. In patients with chronic low back pain, the lumbar flexion relaxation phenomenon measured by surface electromyography (sEMG) differs from that in healthy individuals. However, sEMG activity in axSpA patients has not been studied. The purpose of this study was to analyze the flexion relaxation phenomenon in axSpA patients. A study evaluating 39 axSpA patients and 35 healthy controls was conducted. sEMG activity at the erector spinae muscles was measured during lumbar full flexion movements. sEMG activity was compared between axSpA patients and the controls, as well as between active (BASDAI ≥ 4) and non-active (BASDAI < 4) patients. The reliability (using intraclass correlation coefficients (ICC)), criterion validity and discriminant validity using the area Under the curve (AUC) for the inverse flexion/relaxation ratio (1/FRR) were evaluated. Significant differences (p < 0.05) were observed between axSpA patients and the control group in lumbar electric activity, especially during flexion, relaxation, and extension and in FRR and 1/FRR (0.66 ± 0.39 vs. 0.25 ± 0.19, respectively). In addition, significant differences were found between active and non-active but also between non-active and healthy subjects. The sEMG showed good reliability (ICC > 0.8 for 1/FRR) and criterion validity. ROC analysis showed good discriminant validity for axSpA patients (AUC = 0.835) vs. the control group using 1/FRR. An abnormal flexion/relaxation phenomenon exists in axSpA patients compared with controls. sEMG could be an additional objective tool in the evaluation of patient function and disease activity status.

Measuring Spinal Mobility Using an Inertial Measurement Unit System: A Validation Study in Axial Spondyloarthritis.

Portable inertial measurement units (IMUs) are beginning to be used in human motion analysis. These devices can be useful for the evaluation of spinal mobility in individuals with axial spondyloarthritis (axSpA). The objectives of this study were to assess (a) concurrent criterion validity in individuals with axSpA by comparing spinal mobility measured by an IMU sensor-based system vs. optical motion capture as the reference standard; (b) discriminant validity comparing mobility with healthy volunteers; (c) construct validity by comparing mobility results with relevant outcome measures. A total of 70 participants with axSpA and 20 healthy controls were included. Individuals with axSpA completed function and activity questionnaires, and their mobility was measured using conventional metrology for axSpA, an optical motion capture system, and an IMU sensor-based system. The UCOASMI, a metrology index based on measures obtained by motion capture, and the IUCOASMI, the same index using IMU measures, were also calculated. Descriptive and inferential analyses were conducted to show the relationships between outcome measures. There was excellent agreement (ICC > 0.90) between both systems and a significant correlation between the IUCOASMI and conventional metrology (r = 0.91), activity (r = 0.40), function (r = 0.62), quality of life (r = 0.55) and structural change (r = 0.76). This study demonstrates the validity of an IMU system to evaluate spinal mobility in axSpA. These systems are more feasible than optical motion capture systems, and they could be useful in clinical practice.

Compensatory increase of VE-cadherin expression through ETS1 regulates endothelial barrier function in response to TNFα.

VE-cadherin plays a central role in controlling endothelial barrier function, which is transiently disrupted by proinflammatory cytokines such as tumor necrosis factor (TNFα). Here we show that human endothelial cells compensate VE-cadherin degradation in response to TNFα by inducing VE-cadherin de novo synthesis. This compensation increases adherens junction turnover but maintains surface VE-cadherin levels constant. NF-κB inhibition strongly reduced VE-cadherin expression and provoked endothelial barrier collapse. Bacterial lipopolysaccharide and TNFα upregulated the transcription factor ETS1, in vivo and in vitro, in an NF-κB dependent manner. ETS1 gene silencing specifically reduced VE-cadherin protein expression in response to TNFα and exacerbated TNFα-induced barrier disruption. We propose that TNFα induces not only the expression of genes involved in increasing permeability to small molecules and immune cells, but also a homeostatic transcriptional program in which NF-κB- and ETS1-regulated VE-cadherin expression prevents the irreversible damage of endothelial barriers.

How to calculate the ASDAS based on C-reactive protein without individual questions from the BASDAI: the BASDAI-based ASDAS formula.

OBJECTIVES: To develop a new equation to calculate the Ankylosing Spondylitis Disease Activity Score based on CRP (ASDAS-CRP) using only the BASDAI total score and CRP. METHODS: Axial SpA (axSpA) patients from the Cordoba Spondyloarthritis Registry cohort were recruited as a derivation cohort, while a retrospective sample from the Spanish Rheumatology Society National Registry of Spondyloarthropathies and Ibero American Spondyloarhtritis Registry registers was used as a validation cohort. We built a new equation based only on the BASDAI and CRP, defining a new formula: the BASDAI-based ASDAS (BASDAS). Linear regression analysis was used to determine the coefficients of the equation in the derivation cohort and it was subsequently validated in the validation cohort. RESULTS: A total of 52 axSpA patients in the derivation cohort and 3359 patients in the validation cohort were included. In the derivation cohort, the mean BASDAS [2.24 (s.d. 0.90)] was very similar to the ASDAS-CRP [2.23 (s.d. 0.95)], with a very strong correlation (r = 0.96, P < 0.001). In the validation cohort, the mean BASDAS was 3.31 (s.d. 1.37) and the ASDAS-CRP was 3.19 (s.d. 1.27), which also had a very strong correlation (r = 0.95, P < 0.001). Intraclass correlation coefficients were excellent in both cohorts (0.963 and 0.947, respectively). CONCLUSION: The BASDAS performs similarly to the ASDAS-CRP and can be calculated with only the BASDAI total score and CRP, allowing evaluation of disease activity in retrospective studies where the individual items of the BASDAI are not available.

Efectividad de los sistemas de pulido intraoral y extraoral para superficies cerámicas: Estudio comparativo in vitro / Effectiveness of intraoral and extraoral polishing systems for ceramic surfaces: In vitro comparative study / Eficácia dos sistemas de polimento intra e extrabucal para superfícies cerâmicas: Estudo comparativo in vitro

El correcto ajuste y pulido de las restauraciones cerámicas dentales es fundamental para preservar la durabilidad e integridad estructural del material y de su antagonista. Objetivo: Determinar la efectividad de los sistemas de pulido intraoral y extraoral para cerámicas. Materiales y Métodos: Estudio experimental in vitro. Se elaboraron 40 muestras de cerámica felsdespática (Denstply, Ceramco III) en forma de disco (7mm de diámetro y 3mm de espesor), posteriormente todas las muestras fueron glaseadas y se conformaron aleatoriamente cuatro grupos, siendo: G1: Control Positivo (Porcelana glaseada), G2: Abrasión con fresas de diamante y sistema de pulido extraoral (Masterdent), G3: Abrasión con fresas de diamante y sistema de pulido intraoral (Jota), G4: Abrasión con fresas de diamante y sistema de pulido intraoral (RA-KIT). Se evaluó la rugosidad de las superficies abrasionadas y pulidas mediante un rugosímetro digital (TESTER SRT-6200 patrón de rugosidad Ra 1,64um, velocidad 0,1135mm/s longitud de onda 0,25mm). El análisis estadístico fue a través de los test de ANOVA y Tukey con un nivel de significancia del 5%. Resultados: No hubo diferencia significativa entre G3 respecto del grupo control positivo (p=0,455), mientras que los grupos G2 y G4 presentaron diferencias estadísticamente significativas de los demas grupos (<0,001). Conclusión: El sistema de pulido intraoral (G3 JOTA) mostró mayor efectividad y no presentó diferencia significativa con respecto a la cerámica glaseada.

The correct adjustment and polishing of dental ceramic restorations is essential to preserve the durability and structural integrity of the ceramic material and its antagonist. Objective: To determine the effectiveness of the intraoral and extraoral polishing systems for ceramics. Materials and Methods: 40 samples of feldspathic porcelain (Denstply, Ceramco III) were made in the form of a disk (7mm in diameter and 3mm in thickness), subsequently all samples were glazed and four groups were randomly formed: G1 Positive Control ( Glazed porcelain), G2 abrasion with diamond burs and extraoral polishing system (Masterdent), G3 abrasion with diamond burs and intraoral polishing system (Jota), G4 abrasion with diamond burs and intraoral polishing system (RA-KIT) The roughness of the abrasive and polished surfaces was evaluated by means of a digital roughness meter (TESTER SRT-6200 roughness pattern Ra 1.64um, velocity 0.1135 mm/s wavelength 0.25mm). The statistical analysis was through the ANOVA and Tukey tests with a significance level of 5%. Results: Anova showed significant differences in all groups (p <0.05). Tukey identified that there is no significant difference between groups G1 and G3 (p> 0.05), while for groups G2 and G4 there were statistically significant differences (p <0.05) with respect to G1. Conclusion: The G3 intraoral polishing system (JOTA) showed greater effectiveness and no significant difference respect to the control group

O correto ajuste e polimento das restaurações dentárias é essencial para preservar a durabilidade e a integridade estrutural do material cerâmico e seu antagonista Objetivo: Determinar a eficácia dos sistemas de polimento intraoral e extra-oral para cerâmica. Materiais e Métodos: 40 amostras de porcelana feldspática (Denstply, Ceramco III) foram confeccionadas (7mm de diâmetro e 3mm de espessura), posteriormente todas as amostras foram vitrificadas e divididas aleatoriamente em quatro grupos: G1 Controle Positivo (Porcelana esmaltada), G2 abrasão com brocas de diamante e sistema de polimento extra-oral (Masterdent), G3 abrasão com brocas de diamante e sistema de polimento intraoral (Jota), G4 abrasão com diamantes e sistema de polimento intraoral (RA-KIT). A rugosidade das superfícies abrasivas e polidas foi avaliada com um medidor digital de rugosidade (TESTER SRT-6200, Ra 1.64um, velocidade 0.1135 mm/s, comprimento de onda 0.25mm). O análise estatístico foi feito pelos testes ANOVA e Tukey, com um nível de significância de 5%. Resultados: Anova apresentou diferenças significativas em todos os grupos (p <0,05). Tukey identificou que não há diferença significativa entre os grupos G1 e G3 (p> 0,05), enquanto para os grupos G2 e G4 houve diferenças estatisticamente significantes (p <0,05) em relação ao G1. Conclusão: O sistema de polimento intraoral G3 (JOTA) apresentou maior efetividade e não houve diferença significativa em relação ao grupo controle.

High Reproducibility of an Automated Measurement of Mobility for Patients with Axial Spondyloarthritis.

OBJECTIVE: Conventional measures of spinal mobility used in the assessment of patients with axial spondyloarthritis (axSpA), such as the Bath Ankylosing Spondylitis Metrology Index and its components, are subject to interobserver variability. The University of Córdoba Ankylosing Spondylitis Metrology Index (UCOASMI) is a validated composite index based on a motion video-capture system, UCOTrack. Our objective was to assess its reproducibility in clinical practice settings. METHODS: We carried out an observational study of repeated measures in 3 centers. Video-capture systems were installed and adapted to clinical rooms. Patients with axSpA and stable disease were selected by consecutive stratified sampling [disease duration, sex, and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)]. Intraobserver reliability of the UCOASMI and of conventional measures was tested 3-5 days apart. For interobserver reliability, 3 patients from each center were evaluated in the other centers, within 3-7 days. The intraclass correlation coefficients (ICC) were calculated. RESULTS: Thirty patients were included (73% men, mean age 53 yrs, mean BASDAI 3.0). Interobserver and intraobserver ICC of the UCOASMI was 0.98. Conventional measurements showed lower but adequate reproducibility as well, except for interobserver reliability of lateral flexion (0.41), cervical rotation (0.61), and Schöber test (0.07), and intraobserver reliability of tragus-to-wall distance (0.30). CONCLUSION: Reproducibility of the UCOASMI seems very high, and apparently more reliable than conventional measures of mobility.

Evaluation of quality of life in patients with axial spondyloarthritis and its association with disease activity, functionality, mobility, and structural damage.

To evaluate quality of life (QoL) in patients with axial spondyloarthritis (axSpA) and its association with disease activity, functionality, structural damage, and spinal mobility, using patient-reported outcomes. This was an observational, cross-sectional, and single-center study in which 100 consecutive patients with axSpA were included. We obtained from all patients' sociodemographic data and values related to disease activity, functionality, structural damage, mobility, and quality of life. The Ankylosing Spondylitis Quality of Life Questionnaire (ASQoL) was considered as the primary outcome. Pearson r statistic, Student's T test, and univariate and multivariate linear regressions were performed to relate ASQoL with the studied covariates. Mean ASQoL score in all patients was 4.02 ± 2.81, with statistically significant differences between male and female (3.61 ± 2.80 vs. 4.83 ± 2.70). Patients with high disease activity (measured by the ASAS-endorsed Disease Activity Score, ASDAS > 2.1) showed higher mean score in ASQoL than those with low disease activity (ASDAS ≤ 2.1) (3.21 ± 0.74 vs. 1.43 ± 0.43, p < 0.001). ASQoL presented a significant linear correlation with BASDAI, BASFI, and ASDAS (r > 0.60). However, disease duration was not significantly correlated with ASQoL. Finally, the 68.9% of the ASQoL variability (R2 = 0.689) was determined by BASDAI, BASFI, and mSASSS, presenting mSASSS a negative regression coefficient (- 0.035). In our study, the impairment of QoL was mainly associated with disease activity (BASDAI) and worsening of functionality (BASFI). However, there is an inverse relationship between the worsening of QoL and structural damage. In addition, disease duration does not seem to influence the patient's welfare.

Is spinal mobility in patients with spondylitis determined by age, structural damage, and inflammation?

OBJECTIVE: To explore the association between mobility, inflammation, and structural damage in ankylosing spondylitis (AS). METHODS: Patients with AS were included in a cross-sectional study in which spinal mobility was measured by the Bath Ankylosing Spondylitis Metrology Index (BASMI) and by the University of Córdoba Ankylosing Spondylitis Metrology Index (UCOASMI), based on an automated motion analysis. Structural damage was measured by the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS), and activity by the Ankylosing Spondylitis Disease Activity Score (ASDAS) and the Bath Ankylosing Spondylitis Disease Activity (BASDAI). We analyzed the correlations between variables, as well as interaction by multiple linear regression models to reach a predictive equation. RESULTS: Fifty AS patients, mainly men in their mid-40s and with moderate levels of disease activity and structural damage, were included in the study. BASMI and UCOASMI scores showed a strong correlation (r = 0.89). UCOASMI scores correlated stronger than BASMI with structural damage (r = 0.72 versus r = 0.67) and patient's age (r = 0.68 versus r = 0.56). Correlations of mobility were weaker with disease activity by the ASDAS (r = 0.38) and BASDAI (r = 0.49), and disease duration (r = 0.40). Multiple linear regression showed that factors associated to mobility by UCOASMI were age, the BASDAI, mSASSS, ASDAS (0:<2.1, 1:≥2.1), and disease duration >15 years. The largest weight in the equation corresponded to the mSASSS. The association between the ASDAS and UCOASMI is dependent on disease duration. CONCLUSION: Mobility in AS is influenced by both structural damage and activity, but definitely also by age and disease duration. Improved mobility should be a relevant target in AS, even more prominently than activity, given its closer relation to structural damage.

EURADOS intercomparison on emergency radiobioassay.

Nine laboratories participated in an intercomparison exercise organised by the European Radiation Dosimetry Group (EURADOS) for emergency radiobioassay involving four high-risk radionuclides ((239)Pu, (241)Am, (90)Sr and (226)Ra). Diverse methods of analysis were used by the participating laboratories for the in vitro determination of each of the four radionuclides in urine samples. Almost all the methods used are sensitive enough to meet the requirements for emergency radiobioassay derived for this project in reference to the Clinical Decision Guide introduced by the NCRP. Results from most of the methods meet the requirements of ISO 28218 on accuracy in terms of relative bias and relative precision. However, some technical gaps have been identified. For example, some laboratories do not have the ability to assay samples containing (226)Ra, and sample turnaround time would be expected to be much shorter than that reported by many laboratories, as timely results for internal contamination and early decisions on medical intervention are highly desired. Participating laboratories are expected to learn from each other on the methods used to improve the interoperability among these laboratories.

Validation of a new objective index to measure spinal mobility: the University of Cordoba Ankylosing Spondylitis Metrology Index (UCOASMI).

Spinal mobility measures are subject to high variability and subjectivity. Automated motion capture allows an objective and quantitative measure of mobility with high levels of precision. To validate the University of Cordoba Ankylosing Spondylitis Metrology Index (UCOASMI), an index measure of spinal mobility, based on automated motion capture, validation studies included the following: (1) validity, tested by correlation--Pearson's r--between the UCOASMI and the mobility index Bath Ankylosing Spondylitis Metrology Index (BASMI), and a measure of structural damage, the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS); (2) reliability, with internal consistency tested by Cronbach's alpha, test-retest by intraclass correlation coefficient (ICC) after 2 weeks, and error measurement, by variation coefficient (VC) and smallest detectable difference (SDD); and (3) responsiveness, by effect size (ES) in a clinical trial of anti-TNF. Patients for the different studies all had ankylosing spondylitis. Validity studies show correlation between the BASMI (r = 0.881) and the mSASSS (r = 0.780). Reliability studies show an internal consistency of Cronbach's α = 0.894, intra-observer ICC = 0.996, test-retest ICC = 0.996, and a measurement error of VC = 2.80% and SDD = 0.25 points. Responsiveness showed an ES after 24 weeks of treatment of 0.48. In all studies, the UCOASMI's performance was better than that of the BASMI. The UCOASMI is a validated index to measure spinal mobility with better metric properties than previous indices.

Assessment of spinal mobility in ankylosing spondylitis using a video-based motion capture system.

This paper describes the use of a video-based motion capture system to assess spinal mobility in patients with ankylosing spondylitis (AS). The aim of the study is to assess reliability of the system comparing it with conventional metrology in order to define and analyze new measurements that reflect better spinal mobility. A motion capture system (UCOTrack) was used to measure spinal mobility in forty AS patients and twenty healthy subjects with a marker set defining 33 3D measurements, some already being used in conventional metrology. Radiographic studies were scored using the modified Stoke Ankylosing Spondylitis Spine Score index (mSASSS). Test-retest reliability studies were performed on the same day and over a two-week period. Motion capture shows very high reliability with Intraclass Correlation Coefficient values ranging from 0.89 to 0.99, low Standard Error of the Measurement (0.37-1.33 cm and 1.58°-6.54°), correlating very well with the Bath Ankylosing Spondylitis Metrology Index (BASMI) (p < 0.001) and, in some individual measures (cervical flexion, cervical lateral flexion, back inclination, shoulder-hip angle and spinal rotation), with mSASSS (p < 0.01). mSASSS also added significantly to the variance in multivariate linear regression analysis to certain measures (back inclination, cervical flexion and cervical lateral flexion). Quantitative results obtained with motion capture system using the protocol defined show to be highly reliable in patients with AS. This technique could be a useful tool for assessing the outcome of the disease and for monitoring the evolution of spinal mobility in AS patients.

On the modeling of aggregates of an optically active regioregular polythiophene.

The conformational properties of the optically active regioregular poly[(R)-3-(4-(4-ethyl-2-oxazolin-2-yl) phenyl) thiophene] (PEOPT) were explored by molecular dynamics on a single chain using several solvents of increasing polarity. Furthermore, their aggregate formation was studied over a wide range of temperatures using a replica exchange molecular dynamics simulation providing simulation data representative of the equilibrium behaviour of their aggregates. Results show a clear tendency of PEOPT to keep a syn-gauche conformation between continuous backbone thiophene rings favouring a bent chain structure in solvent. After studying their aggregation behaviour in acetonitrile, a strong tendency to pack stabilizing structures that reinforce the chirality of the polymer, in concordance with experimental data, was found. Two different aggregated structures were observed depending on oligomer length, a self-assembled helical aggregate based on stacked octamers and a bent double helix aggregate in large oligomers.

Auditory neuropathy in patients carrying mutations in the otoferlin gene (OTOF).

Inherited hearing impairment affects one in 2,000 newborns. Nonsyndromic prelingual forms are inherited mainly as autosomal recessive traits, for which 16 genes are currently known. Mutations in the genes encoding connexins 26 and 30 account for up to 50% of these cases. However, the individual contribution of the remaining genes to the whole remains undetermined. In addition, for most of the genes there is a need for studies on genotype-phenotype correlations, to identify distinctive clinical features which may direct the molecular diagnosis to specific genes. Here we present a mutation analysis and a genotype-phenotype correlation study on the gene encoding otoferlin (OTOF), responsible for the DFNB9 subtype of prelingual hearing impairment. Four novel mutations were identified: c.2122C>T (p.Arg708Ter), c.4275G>A (p.Trp1425Ter), c.4362+2T>G, and c.5860_5862delATC (p.Ile1954del). A total of 37 subjects with mutations in OTOF were studied clinically. They were phenotypically homogeneous, having profound hearing impairment with very early onset, as shown by pure-tone audiometry and auditory brainstem responses. Magnetic resonance imaging and computed tomography did not reveal any inner ear malformation. Unexpectedly, transient evoked otoacoustic emissions (TEOAEs) were present, either bilaterally or unilaterally in 11 subjects. Altogether, clinical data of these subjects met the diagnostic criteria of auditory neuropathy. A total of 10 subjects had been successfully provided with cochlear implants. The results of our study indicate that genetic diagnosis of subjects with auditory neuropathy and profound hearing impairment should be directed to the otoferlin gene. Our data are of concern to universal screening programs which use TEOAEs as the first detection test for hearing impairment in newborns, since this technique may overlook a nonnegligible proportion of cases.