Fracture risk prediction in postmenopausal women from GO Study: the comparison between FRAX, Garvan, and POL-RISK algorithms

In the longitudinal, retrospective study, the ability of the FRAX, Garvan, and POL-RISK algorithms to predict osteoporotic fractures was compared in a group of 457 women. Using the rigid threshold of 10% showed a significant discrepancy in sensitivity and specificity of all tools. New thresholds for high risk of fractures were established for each calculator separately: 6.3% for FRAX major fracture, 20.0% for Garvan any fracture, and 18.0% for POL-RISK any fracture. Such thresholds allow for improving the diagnostic accuracy of all three calculators.

INTRODUCTION

The aim of the longitudinal, retrospective study was to compare three tools designed to assess fracture risk: FRAX, Garvan, and POL-RISK in their prediction of fracture incidence.

MATERIAL

The study group consisted of 457 postmenopausal women with a mean age of 64.21 ± 5.94 years from the Gliwice Osteoporosis (GO) Study. Comprehensive data on clinical factors related to fractures were collected for all participants. Bone densitometry was performed at the proximal femur using the Prodigy device (GE, USA). Fracture risk was established using the FRAX, Garvan, and POL-RISK algorithms. Data on the incidence of osteoporotic fractures were collected over the last 10 years.

RESULTS

During the period of observation 72, osteoporotic fractures occurred in 63 subjects. For a preliminary comparison of the predictive value of analyzed diagnostic tools, the fracture risk threshold of 10% was used. For FRAX, the fracture probability exceeding 10% was observed only in 11 subjects who experienced fractures; thus, the fracture was properly predicted only in 22.9% of women. For Garvan, the respective value was 90.5%, and for POL-RISK, it was 98.4%. That gave a very low true positive value for FRAX and a very high false positive value for Garvan and POL-RISK. Based on ROC curves, new thresholds for high risk of fractures were established for each calculator separately: 6.3% for FRAX major fracture, 20.0% for Garvan any fracture, and 18.0% for POL-RISK any fracture. Such thresholds improve the diagnostic accuracy of all compared fracture prediction tools.

CONCLUSION

The current study showed that different fracture risk assessment tools, although having similar clinical purposes, require different cut-off thresholds for making therapeutic decisions. Better identification of patients requiring therapy based on such an approach may help reduce the number of new fractures.

ISCEV standard for clinical pattern electroretinography (2024 update)

The pattern electroretinogram (PERG) is a localized retinal response evoked by a contrast-reversing pattern, usually a black and white checkerboard, which provides information about macular and retinal ganglion cell function. This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV; www.iscev.org ) presents an updated and revised Standard for clinical PERG testing. This replaces the 2013 and all earlier versions. Minimum protocols for basic PERG stimuli, recording methods and reporting are specified, to promote consistency of methods for diagnosis and monitoring purposes, while responding to evolving clinical practices and technology. The main changes in the updated ISCEV Standard for clinical PERG include expanded guidance about large stimulus fields, stimulus parameters for simultaneous PERG and pattern visual evoked potential recording, baseline drift correction, and use of consistent ambient room lighting. These changes aim to provide a clinically relevant document about current practice which will facilitate good quality recordings and inter-laboratory comparisons.

Optimal fracture prediction thresholds for therapy onset, established from FRAX and Garvan algorithms: a longitudinal observation of the population representative female cohort from the RAC-OST-POL Study

The study shows that the use of unified cutoff thresholds to identify high fracture risks by two popular calculators-FRAX and Garvan-leads to a significant discrepancy between the prediction of fractures and their actual prevalence over the period of 10 years. On the basis of the ROC analyses, a proposal of differentiated thresholds is presented. They were established at 6% for FRAX major fracture risk, 1.4% for FRAX hip fracture risk, 14.4% for Garvan any fracture risk, and 8.8% for Garvan hip fracture risk.

PURPOSE/INTRODUCTION

The aim of the study was to verify how much were the tools, designed to predict fracture risks, precise vs. the actual fracture incidence values over a prospective observation.

METHODS

The study group consisted of a population-based postmenopausal sample from the RAC-OST-POL Study. At baseline, there were 978 subjects at the mean age of 66.4 ± 7.8 years and, after a 10-year follow-up, 640 women remained at the mean age of 75.0 ± 6.95 years. At baseline, the fracture risk was established by the FRAX and Garvan tools.

RESULTS

During the observation period, 190 osteoporotic fractures were identified in 129 subjects. When high-risk fracture cutoff thresholds (of 10% for major/any and 3% for hip fractures) were employed, only 19.59% of major fractures and 50% of hip fractures were identified in the high-risk group. For the Garvan tool, the percentage of correctly predicted fractures for any and hip fractures was 86.05% and 71.43%, respectively. Nevertheless, the fracture prediction by the Garvan tool was associated with the qualification of numerous subjects to the high-risk group, who subsequently did not experience a fracture in the 10-year follow-up period (false-positive prediction). Based on the ROC analyses, new high-risk thresholds were proposed individually for each calculator, improving the sensitivity, specificity, and diagnostic accuracy of these tools. They were established at 6% for FRAX major fracture risk, 1.4% for FRAX hip fracture risk, 14.4% for Garvan any fracture risk, and 8.8% for Garvan hip fracture risk.

CONCLUSIONS

The current prospective study enabled to establish new, optimal thresholds for therapy initiation. Such a modified approach may enable a more accurate identification of treatment requiring patients and, in consequence, reduce the number of new fractures.

OP0297 DIAGNOSTIC VALUE OF LABIAL MINOR SALIVARY GLAND BIOPSY IN THE DIAGNOSIS OF SJÖGREN’S SYNDROME: HISTOLOGIC FINDINGS OF 678 BIOPSIES AND ASSOCIATIONS WITH LABORATORY MARKERS, CLINICAL AND PATIENT ASSOCIATED PARAMETERS

Background

Histologic findings of salivary gland biopsy are a crucial part of the current ACR-EULAR classification criteria of Sjögren’s cyndrome (SS) (1). Particularly, the finding of a focal lymphocytic sialadenitis (focus score ≥ 1/4 mm2) corresponds to 3 scoring points out of 4 needed to reach a positive classification for SS [1]. Moreover, there is increasing evidence that salivary gland biopsy can provide prognostic information regarding systemic involvement and the development of lymphoma in the context of the disease.

Objectives

The aim of this study was to analyze the minor labial salivary gland (MLSG) biopsy findings of a large SS cohort and to examine their associations with disease specific laboratory markers, clinical and patient associated parameters.

Methods

We included all patients from two large rheumatological medical departments in Germany having undergone a diagnostic MLSG between 01/2010 and 12/2019. The data have been collected partly in a retrospective and party in a prospective manner. Next to the examination of histological results we focused on activity and chronicity parameters of the underlying disease, autoantibodies, presence of systemic and haematological involvement, as well as on current and previous comorbidities. The statistical analyses included sensitivity and specificity examinations via receiver operating characteristics (ROC), correlation analyses, Mann-Whitney-U-Tests and ANOVA.

Results

In total, 678 patients have been included (615 ♀, median age 55 years [47-63, IQR]). 306 patients (45.1%) had a positive focus score. The remaining 372 patients with a negative focus score served as a control group. There were significant correlations between the level of the focus score and nicotine use (p=0.002), hypergammaglobulinemia [1.27 (0.71-3.36, IQR) vs. 0.73 (0.0-0.76, IQR); p<0.001], ANA positivity [1.18 (0.11-3, IQR) vs. 0.64 (0-1.34, IQR); p<0.001] and rheumatoid factor positivity (p<0.001). Moreover, focus score levels correlated significantly with disease modifying antirheumatic treatment [1 (0-2.34, IQR) vs. 0.87 (0-1.8, IQR); p=0.004] and weakly significantly with erythrocyte sedimentation rate (r=0.235, p<0.001).

Within the group of patients with primary SS there were significant correlations between the level of the focus score and presence of systemic involvement [2 (1.1 - 4, IQR) vs. 1.44 (1-2.62, IQR); p=0.015], glandular involvement [4 (2.98-6.2, IQR) vs. 0.72 (1.6-3, IQR); p=0.007] and haematologic manifestations (p=0.002). SSA-antibodies showed the best diagnostic performance compared to MLSG, as examined by ROC (Table 1).

Table 1.

Diagnostic value of SSA-antibodies, Sicca, Schirmer´s and Saxon´s test compared to minor labial salivary gland biopsy findings (reference focus score ≥ 1/ 4 mm2)

SpecificitySensitivityArea under the curveSSA-Ro antibodies88.2%43.4%0.658Sicca15%91.9%0.535Schirmer´s test27.3%73%0.507Saxons´s test57.9%39%0.541

Interestingly enough, among 159 patients who were admitted due to the diagnosis of primary fibromyalgia (FM), 63 (39.6%) could be diagnosed with SS on the basis of histologic findings and the ACR-EULAR classification criteria.

Conclusion

By examining one of the largest cohorts in the literature we could show that MLSG biopsy findings not only play a key role in the classification and diagnosis of SS, but could also provide important information regarding the presence of a systemic, glandular or haematological involvement. Furthermore, MLSG can help differentiate patients with FM and other chronic pain disorders from patients with subclinical SS who suffer primarily from chronic pain.

References

[1]Shiboski CH, et al. International Sjögren’s Syndrome Criteria Working Group. 2016 American College of Rheumatology/European League Against Rheumatism Classification Criteria for Primary Sjögren’s Syndrome. Arthritis Rheumatol. 2017 Jan;69(1):35-45.

Disclosure of Interests

None declared

Immunohistochemical diagnosis of onychomycosis by monoclonal antibodies detection of dermatophyte T. rubrum

Introduction/Objective

Onychomycosis is one of the most common nail infection disorders, caused predominantly by T. rubrum. Currently, PAS stain is the gold standard for histological onychomycosis detection. However, it does not differentiate between the types of fungi. In addition, PAS stains will only provide a positive or negative result. This leaves physicians to prescribe medications that may be ineffective in treating the root cause of the infection. By discerning the causative specie, physicians can provide a more targeted and effective anti-fungal therapy. A novel monoclonal antibody can be utilized to improve histological findings of T. rubrum. Our study takes a step forward to bring the monoclonal antibody into histological application. We have developed a new monoclonal antibody stain which binds to T. rubrum in vitro. For our project, we will perform in vivo staining on clinical nail samples using the novel monoclonal antibody. Developing a new applicable technique will benefit patients with onychomycosis as well as promote research in targeted identification of other infectious pathologies.

Methods/Case Report

Data from Bach Dx’s collaboration demonstrate isolation and validation of mice monoclonal antibody candidates for T. rubrum. Isotype IgG1/kappa 17B6 had the highest binding pair signal to the analyte. Direct ELISA of 17B6.1E3 shows immunoreactivity to T. rubrum. HRP and AP conjugates to 17B6 mice monoclonal antibody are produced (Rockland Immunochemicals Inc. Gilbertsville, PA). Histology slides analyzed for routine onychomycosis analysis at Bach Diagnostics are subject to secondary analysis. 220 retrospective, unstained nail slides from 55 patients will be stained using the 17B6 stains. 40 patients were known to have tested for onychomycosis caused by T. rubrum, 5 by Candida albicans, 5 by T. interdigitale, and 5 tested negative. All samples were confirmed by histology and molecular tests. H&E, PAS, and naked antibody stains will serve as controls. HRP and AP conjugated 17B6 monoclonal antibody stains will be optimized to Quantum Hdx (StatLab Lodi, CA) on July 12th, 2021 when the stains are scheduled to arrive. Images will be captured by light microscopy, and analyzed quantitatively and qualitatively.

Results (if a Case Study enter NA)

We hope to show preferential staining of antibody stains to positive T. rubrum cases by end of July 2021.

Conclusion

Conclusion pending based on results.

Clinical impact on treatment and prognosis of advanced cardiac imaging with echocardiography in the acute setting of a COVID-19 infection

Background and objectives

Despite myocardial injury being related to excess mortality in acute COVID-19 infection, its impact on imaging findings remains unclear. This study aimed to characterize transthoracic echocardiographic (TTE) findings in patients admitted with COVID-19 infections and its impact on management and prognosis.

Methods

A prospective observational cohort study was performed among 66 COVID-19 patients who were admitted to a tertiary center between March 1 and May 25, 2020 and underwent TTE. High-sensitivity troponin I (hs-cTnI) data, echocardiographic assessment of right and left ventricular (LV) functional parameters, strain, and myocardial work analysis were obtained.

Results

2025 patients were admitted with COVID-19 and in 200 a complete TTE study was performed. Due to poor image quality, only 66 studies were included in the final analysis. The median age was 62 years (IQR, 55–70) and 59.1% of patients were males. The most common comorbidity was hypertension (47%), followed by smoking history (30.3%), atrial fibrillation (9.1%), and chronic obstructive pulmonary disease (7.9%). More than half of the patients (39, 59%) were admitted to the ICU, and half of them (33, 50%) required invasive mechanical ventilation. TTE was mainly indicated because of concerns for systemic conditions (50%) and evaluation of hemodynamic assessment (30%). Thirty-six patients (54.5%) had an abnormal TTE result and 57% had elevated hs-cTnI levels. The most common cardiac abnormality was LV diastolic dysfunction in 33% of the patients, followed by right ventricular dysfunction (12%) and LV dysfunction (6%) (Figure 1). LV GLS was reduced in 48.5% of the cases. Myocardial work performance indices were all reduced in patients with an abnormal TTE (GWI 30%, GCW 30%, GWW 40%, and GWE 40%), although differences were not significant (P&gt;0.2 for all parameters). Patients with an abnormal TTE were older and presented a higher cardiovascular risk profile. There were no significant differences in the levels of D-dimer, NTproBNP, and hs-cTnI between patients with and without diastolic dysfunction, RV, or LV dysfunction (P&gt;0.3 for all parameters). Using Spearman rank correlation, there was an inverse relationship between hs-cTnI and LV strain and myocardial work analysis. TTE results impacted clinical management in 60 patients, mainly de-escalation of medical treatment (Figure 2). Abnormal TTE results did not impact in-hospital outcomes.

Conclusions

Severe echocardiographic abnormalities are uncommon in hospitalized patients with COVID-19 infections, presenting mostly with subclinical myocardial changes, such as diastolic dysfunction, reduced LV GLS, and myocardial work indices, both associated with high-sensitivity troponin I elevation. An echocardiographic study should be limited to rule out long-term ICU complications or to evaluate hemodynamic instability. Although TTE was a valuable tool for guiding management, it had no significant impact on prognosis.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Findings on TTE studies.Figure 2. Changes in management.

[Neurological symptoms in a patient on anti-TNF therapy, methotrexate and prednisolone for rheumatoid arthritis]

A 78-year-old woman with rheumatoid arthritis on TNF-α inhibitor, methotrexate and prednisolone presented with severe but unspecific symptoms such as leg weakness, shivering, bifrontal headache, nausea and staggering. The broad range of differential diagnoses lead to intricate and time-consuming diagnostic procedures. Serology, magnetic resonance imaging and microbiological investigations represent important steps to make the final diagnosis of cerebral toxoplasmosis. Both diagnostic approach and therapy require close cooperation of different disciplines. Therapies of rheumatoid arthritis as well as of toxoplasmosis are based on a long-term treatment and could be associated with numerous harmful side effects. Continuous monitoring and permanent adjustment of therapy regimes are therefore mandatory.

[New DIN and ISO norms for determination of visual acuity]

Recently, three international norms (ISO) for visual acuity assessment were revised. The DIN EN ISO 8596:2018 stipulates the Landolt C eye chart as the standard optotype and specifies display characteristics. An informative annex lists clinical optotypes for the first time. These include the ETDRS chart, Snellen chart and pediatric optotypes; however, these clinical optotypes do not have the same status as the Landolt C chart, since even with identical font size and stroke width they may differ in recognizability. The technical report ISO/TR 19498:2015 complements DIN EN ISO 8596. A scientifically appropriate procedure is described, which enables a quantitative correlation of clinical optotypes with the Landolt C chart. The DIN EN ISO 10938:2016 describes the required optical quality of optotypes. For the first time, electronic devices are explicitly approved for standardized visual acuity tests. Consequently, according to this amendment electronic devices may be used for acuity assessment for ophthalmological expert opinions according to DIN 58220, part 3.

Co-Creation in participatory epidemiology

Background

Participatory epidemiology aims to involve public health professionals, health activists, and community representatives in epidemiological studies. Paramount are equitable research partnerships for identifying the causes of health problems, generating data, and finding ways to address health related issues. Alongside the research process, co-creation informs various aspects of participatory epidemiology.

Methods

A scoping review was conducted to develop the conceptual foundations of participatory epidemiology. Workshops with staff from public health administration and public health practitioners were held to check feasibility of the concept for public health monitoring, policy making and the development of relevant public health recommendations. From this research, principles and practices of co-creation were identified.

Results

Co-creation is of importance for participatory epidemiology. 1) Methodologically: Co-creation asks to apply multiple perspectives (research, practice, communities) in data collection and synthesis, what may require the adaption of a given study design. 2) Research practice: Co-creation in participatory epidemiology means producing epidemiologic evidence while contributing to concrete public health interventions, two goals that have to be balanced. 3) Personal attitudes: In participatory epidemiology academic researchers, practitioners, and community representatives are requested to acknowledge each other as co-researching partners, which can be challenging for each of them.

Conclusions

Co-creation is a prerequisite for establishing equitable research partnerships. In participatory epidemiology, co-creation offers ways to produce meaningful knowledge for research and practice.

Main messages

Participatory epidemiology offers ways of producing epidemiologic evidence while contributing to public health practice. Co-creation is a prerequisite, way, and attitude to conduct meaningful research, hopefully for all of those who are involved.

Calculation and plotting of retinal nerve fiber paths based on Jansonius et al. 2009/2012 with an R program

The data presented in this article are related to the research article entitled “Retinal conduction speed analysis reveals different origins of the P50 and N95 components of the (multifocal) pattern electroretinogram” (Bach et al., 2018) [1]. That analysis required the individual length data of the retinal nerve fibers (from ganglion cell body to optic nerve head, depending on the position of the ganglion cell body). Jansonius et al. (2009, 2012) [2,3] mathematically modeled the path morphology of the human retinal nerve fibers. We here present a working implementation with source code (for the free and open-source programming environment “R”) of the Jansonius’ formulas, including all errata. One file defines Jansonius et al.’s “phi” function. This function allows quantitative modelling of paths (and any measures derived from them) of the retinal nerve fibers. As a working demonstration, a second file contains a graph which plots samples of nerve fibers. The included R code runs in base R without the need of any additional packages.

[Cut-off filter : Physical and physiological basics]

Light filters with wavelength-dependent transmission and in particular cut-off or step filters (steep dependence of transmission on wavelength) have a broad optical application and are relevant in ophthalmology. This article describes some physical and physiological principles of cut-off filters, discusses the physiological aspects of applications, specifically the not always relevant necessity of blue-reducing filters and the lack of efficacy of color filters with color vision deficiencies.

[Edge filters : Medical indications and clinical application]

Edge filters are used in aphakic eyes as a substitute of the natural cut-off filter of the intact eye or in other causes of a lack of light absorption in the eye itself. Furthermore, they can remedy light adaptation disturbances, especially in hereditary retinal diseases and retinal dystrophy. They enhance contrast and reduce glare. In order to choose an adequate cut-off filter it is necessary to let the participants test various filters before prescription. Because of the (absolute) absorption of blue light, cut-off filters normally lead to a loss of ability to drive.

Risk Factors for Fractures Identified in the Algorithm Developed in 5-Year Follow-Up of Postmenopausal Women From RAC-OST-POL Study

The aim of the study was to establish factors with an impact on fracture risk and to develop an algorithm to predict osteoporotic fracture. A total of 978 postmenopausal women from the epidemiological, population-based RAC-OST-POL study with a mean age of 65.7 ± 7.3 years were enrolled. At baseline, bone mineral density at hip and clinical risk factors for fracture were collected. Afterward, each person was asked annually on fracture incidence in the 5-year follow-up. Finally, data for complete 5-year observation were gathered for the group of 802 patients. During the follow-up, 92 osteoporotic fractures occurred in 78 women. The most common fracture site was the forearm (n = 45). The following baseline factors were found as significant for fracture incidence: femoral neck bone mineral density, prior fractures, steroid use, falls within previous 12 months, and height. Fracture risk was predicted by the following formula: Riskoffractureincidence=11+e^{-(-9.899+1.077∗STEROIDS+0.681∗PRIORFALLS+0.611∗PRIORFRACTURES-0.483∗FNTscore+0.042∗HEIGHT)}. In our current longitudinal study, an algorithm predicting fracture occurrence over a period of 5 years was developed. It may find application in daily medical practice.

Super-Resolution Localization Microscopy of γ-H2AX and Heterochromatin after Folate Deficiency

Folate is an essential water-soluble vitamin in food and nutrition supplements. As a one-carbon source, it is involved in many central regulatory processes, such as DNA, RNA, and protein methylation as well as DNA synthesis and repair. Deficiency in folate is considered to be associated with an increased incidence of several malignancies, including cervical cancer that is etiologically linked to an infection with “high-risk” human papilloma viruses (HPV). However, it is still not known how a recommended increase in dietary folate after its deprivation affects the physiological status of cells. To study the impact of folate depletion and its subsequent reconstitution in single cells, we used quantitative chromatin conformation measurements obtained by super-resolution fluorescence microscopy, i.e., single molecule localization microscopy (SMLM). As a read-out, we examined the levels and the (re)positioning of γ-H2AX tags and histone H3K9me3 heterochromatin tags after immunostaining in three-dimensional (3D)-conserved cell nuclei. As model, we used HPV16 positive immortalized human keratinocytes that were cultivated under normal, folate deficient, and reconstituted conditions for different periods of time. The results were compared to cells continuously cultivated in standard folate medium. After 13 weeks in low folate, an increase in the phosphorylation of the histone H2AX was noted, indicative of an accumulation of DNA double strand breaks. DNA repair activity represented by the formation of those γ-H2AX clusters was maintained during the following 15 weeks of examination. However, the clustered arrangements of tags appeared to relax in a time-dependent manner. Parallel to the repair activity, the chromatin methylation activity increased as detected by H3K9me3 tags. The progress of DNA double strand repair was accompanied by a reduction of the detected nucleosome density around the γ-H2AX clusters, suggesting a shift from hetero- to euchromatin to allow access to the repair machinery. In conclusion, these data demonstrated a folate-dependent repair activity and chromatin re-organization on the SMLM nanoscale level. This offers new opportunities to further investigate folate-induced chromatin re-organization and the associated mechanisms.

clickECM: Development of a cell-derived extracellular matrix with azide functionalities

In vitro cultured cells produce a complex extracellular matrix (ECM) that remains intact after decellularization. The biological complexity derived from the variety of distinct ECM molecules makes these matrices ideal candidates for biomaterials. Biomaterials with the ability to guide cell function are a topic of high interest in biomaterial development. However, these matrices lack specific addressable functional groups, which are often required for their use as a biomaterial. Due to the biological complexity of the cell-derived ECM, it is a challenge to incorporate such functional groups without affecting the integrity of the biomolecules within the ECM. The azide-alkyne cycloaddition (click reaction, Huisgen-reaction) is an efficient and specific ligation reaction that is known to be biocompatible when strained alkynes are used to avoid the use of copper (I) as a catalyst. In our work, the ubiquitous modification of a fibroblast cell-derived ECM with azides was achieved through metabolic oligosaccharide engineering by adding the azide-modified monosaccharide Ac₄GalNAz (1,3,4,6-tetra-O-acetyl-N-azidoacetylgalactosamine) to the cell culture medium. The resulting azide-modified network remained intact after removing the cells by lysis and the molecular structure of the ECM proteins was unimpaired after a gentle homogenization process. The biological composition was characterized in order to show that the functionalization does not impair the complexity and integrity of the ECM. The azides within this "clickECM" could be accessed by small molecules (such as an alkyne-modified fluorophore) or by surface-bound cyclooctynes to achieve a covalent coating with clickECM.

STATEMENT OF SIGNIFICANCE

The clickECM was produced by the incorporation of azide-functionalized sugar analogues into the extracellular glycans of fibroblast cell cultures by metabolic oligosaccharide engineering. By introducing these azide groups into the glycan structures, we enabled this cell-derived ECM for bioorthogonal click reactions. Click chemistry provides extremely specific reactions with high efficiency, high selectivity, and high reaction yields. We could show that the azide functionalities within the clickECM are chemically accessible. Based on our here described clickECM technique it will be possible to create and investigate new clickECM materials with tunable bioactive properties and additional functionalities, which offers a promising approach for basic and applied research in the field of biomaterial science, biomedical applications, and tissue engineering.

Clustered localization of EGFRvIII in glioblastoma cells as detected by high precision localization microscopy

For receptor tyrosine kinases supramolecular organization on the cell membrane is critical for their function. Super-resolution fluorescence microscopy techniques have offered new opportunities for the analysis of single receptor localization. Here, we analysed the cluster formation of the epidermal growth factor receptor variant III (EGFRvIII), a deletion variant which is expressed in glioblastoma. The constitutively activated variant EGFRvIII is expressed in cells with an egfr gene amplification and is thought to enhance the tumorigenic potential especially of glioblastoma cells. Due to the lack of an adequate model system, it is still unclear how endogenous EGFRvIII expression alters cellular signalling and if it is organized in clusters like the wild type receptor. We have recently described the establishment of two pairs of iso-genetic cell lines (BS153 and DKMG), displaying endogenous EGFRvIII expression or not. Using these cell lines we investigated single receptor localization of EGFRvIII by high precision localization microscopy. Cluster analysis revealed that EGFRvIII is present in clusters on the surface of the cells, with about 60% or even more receptor molecules being assembled in clusters of approximately 100 nm in diameter whereby the cluster definition was iteratively determined. The signal to signal distance may indicate dimer formation while signal quantification indicates 1 × 10⁶-5 × 10⁶ EGFRvIII molecules per cell. Altogether, these data give unique insights into the membrane surface localization of EGFRvIII in glioblastoma cells. These insights will help to unveil the function of this tumour associated receptor variant which might lead to a better understanding of glioblastoma and therefore could lead to improved therapy approaches.

Phosphatidylcholine passes through lateral tight junctions for paracellular transport to the apical side of the polarized intestinal tumor cell-line CaCo2

Phosphatidylcholine (PC) is the most abundant phospholipid in intestinal mucus, indicative of a specific transport system across the mucosal epithelium to the intestinal lumen. To elucidate this transport mechanism, we employed a transwell tissue culture system with polarized CaCo2 cells. It was shown that PC could not substantially be internalized by the cells. However, after basal application of increasing PC concentrations, an apical transport of 47.1±6.3nmolh(-1)mMPC(-1) was observed. Equilibrium distribution studies with PC applied in equal concentrations to the basal and apical compartments showed a 1.5-fold accumulation on the expense of basal PC. Disruption of tight junctions (TJ) by acetaldehyde or PPARγ inhibitors or by treatment with siRNA to TJ proteins suppressed paracellular transport by at least 50%. Transport was specific for the choline containing the phospholipids PC, lysoPC and sphingomyelin. We showed that translocation is driven by an electrochemical gradient generated by apical accumulation of Cl(-) and HCO3(-) through CFTR. Pretreatment with siRNA to mucin 3 which anchors in the apical plasma membrane of mucosal cells inhibited the final step of luminal PC secretion. PC accumulates in intestinal mucus using a paracellular, apically directed transport route across TJs.

[Dichoptic training for amblyopia]

Dichoptic training is a promising new therapeutic approach to amblyopia, which employs simultaneous and separate stimulation of both eyes (thus dichoptic). The contrast for the good eye is reduced thus aiming at a balance with the amblyopic eye. In contrast to monocular patching, binocular vision is trained by video game tasks that can only be solved binocularly. To date the average gain in visual acuity achieved in currently available studies is only 0.20 ± 0.07 logMAR and is not significantly better than competing treatment options. This article explains the basic approach of dichoptic training, summarizes pertinent studies, names unsolved problems and closes with a personal critical assessment.

Cellular Uptake of Gold Nanoparticles and Their Behavior as Labels for Localization Microscopy

Gold nanoparticles (GNPs) enhance the damaging absorbance effects of high-energy photons in radiation therapy by increasing the emission of Auger-photoelectrons in the nm-μm range. It has been shown that the incorporation of GNPs has a significant effect on radiosensitivity of cells and their dose-dependent clonogenic survival. One major characteristic of GNPs is also their diameter-dependent cellular uptake and retention. In this article, we show by means of an established embodiment of localization microscopy, spectral position determination microscopy (SPDM), that imaging with nanometer resolution and systematic counting of GNPs becomes feasible, because optical absorption and plasmon resonance effects result in optical blinking of GNPs at a size-dependent wavelength. To quantify cellular uptake and retention or release, SPDM with GNPs that have diameters of 10 and 25 nm was performed after 2 h and after 18 h. The uptake of the GNPs in HeLa cells was either achieved via incubation or transfection via DNA labeling. On average, the uptake by incubation after 2 h was approximately double for 10 nm GNPs as compared to 25 nm GNPs. In contrast, the uptake of 25 nm GNPs by transfection was approximately four times higher after 2 h. The spectral characteristics of the fluorescence of the GNPs seem to be environment-dependent. In contrast to fluorescent dyes that show blinking characteristics due to reversible photobleaching, the blinking of GNPs seems to be stable for long periods of time, and this facilitates their use as an appropriate dye analog for SPDM imaging.

In situ optical sequencing and structure analysis of a trinucleotide repeat genome region by localization microscopy after specific COMBO-FISH nano-probing

Trinucleotide repeat expansions (like (CGG)n) of chromatin in the genome of cell nuclei can cause neurological disorders such as for example the Fragile-X syndrome. Until now the mechanisms are not clearly understood as to how these expansions develop during cell proliferation. Therefore in situ investigations of chromatin structures on the nanoscale are required to better understand supra-molecular mechanisms on the single cell level. By super-resolution localization microscopy (Spectral Position Determination Microscopy; SPDM) in combination with nano-probing using COMBO-FISH (COMBinatorial Oligonucleotide FISH), novel insights into the nano-architecture of the genome will become possible. The native spatial structure of trinucleotide repeat expansion genome regions was analysed and optical sequencing of repetitive units was performed within 3D-conserved nuclei using SPDM after COMBO-FISH. We analysed a (CGG)n-expansion region inside the 5' untranslated region of the FMR1 gene. The number of CGG repeats for a full mutation causing the Fragile-X syndrome was found and also verified by Southern blot. The FMR1 promotor region was similarly condensed like a centromeric region whereas the arrangement of the probes labelling the expansion region seemed to indicate a loop-like nano-structure. These results for the first time demonstrate that in situ chromatin structure measurements on the nanoscale are feasible. Due to further methodological progress it will become possible to estimate the state of trinucleotide repeat mutations in detail and to determine the associated chromatin strand structural changes on the single cell level. In general, the application of the described approach to any genome region will lead to new insights into genome nano-architecture and open new avenues for understanding mechanisms and their relevance in the development of heredity diseases.

Mental health disabilities and human rights protections

BACKGROUND

Around the world, reports regularly expose persistent and systemic human rights violations of patients in mental health services and facilities, and of those who are unable to access needed supports. A number of factors contribute - political will; the range and quality of services available; public and professional attitudes to mental health; stigma; health professionals' training and expertise; and available resources.

METHODS

This paper examines one of the main determinants, the legal framework. This sets the parameters for mental health policies and services and for applicable human rights norms and standards that can be realized in practice.

RESULTS

We provide an overview of international human rights instruments in relation to mental health disabilities, and of the major human rights violations in this area. Key implications for mental health law reform are drawn with a particular focus on discrimination and coercive interventions. The major challenges posed by the UN Convention on the Rights of Persons with Disabilities (2006) are examined. Current mental health laws, to greater or lesser degrees, fail to meet the newly required standards. We discuss reforms based on 'generic law' and 'legal capacity' principles that seek to meet those standards.

CONCLUSIONS

We outline some emergent and promising examples of reform. The role of civil society and the importance of the standing of those with mental health disabilities in this process is noted.

Radiation induced chromatin conformation changes analysed by fluorescent localization microscopy, statistical physics, and graph theory

It has been well established that the architecture of chromatin in cell nuclei is not random but functionally correlated. Chromatin damage caused by ionizing radiation raises complex repair machineries. This is accompanied by local chromatin rearrangements and structural changes which may for instance improve the accessibility of damaged sites for repair protein complexes. Using stably transfected HeLa cells expressing either green fluorescent protein (GFP) labelled histone H2B or yellow fluorescent protein (YFP) labelled histone H2A, we investigated the positioning of individual histone proteins in cell nuclei by means of high resolution localization microscopy (Spectral Position Determination Microscopy = SPDM). The cells were exposed to ionizing radiation of different doses and aliquots were fixed after different repair times for SPDM imaging. In addition to the repair dependent histone protein pattern, the positioning of antibodies specific for heterochromatin and euchromatin was separately recorded by SPDM. The present paper aims to provide a quantitative description of structural changes of chromatin after irradiation and during repair. It introduces a novel approach to analyse SPDM images by means of statistical physics and graph theory. The method is based on the calculation of the radial distribution functions as well as edge length distributions for graphs defined by a triangulation of the marker positions. The obtained results show that through the cell nucleus the different chromatin re-arrangements as detected by the fluorescent nucleosomal pattern average themselves. In contrast heterochromatic regions alone indicate a relaxation after radiation exposure and re-condensation during repair whereas euchromatin seemed to be unaffected or behave contrarily. SPDM in combination with the analysis techniques applied allows the systematic elucidation of chromatin re-arrangements after irradiation and during repair, if selected sub-regions of nuclei are investigated.

Measurement of pion, kaon and proton production in proton-proton collisions at [Formula: see text] TeV

The measurement of primary [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] production at mid-rapidity ([Formula: see text] 0.5) in proton-proton collisions at [Formula: see text][Formula: see text] 7 TeV performed with a large ion collider experiment at the large hadron collider (LHC) is reported. Particle identification is performed using the specific ionisation energy-loss and time-of-flight information, the ring-imaging Cherenkov technique and the kink-topology identification of weak decays of charged kaons. Transverse momentum spectra are measured from 0.1 up to 3 GeV/[Formula: see text] for pions, from 0.2 up to 6 GeV/[Formula: see text] for kaons and from 0.3 up to 6 GeV/[Formula: see text] for protons. The measured spectra and particle ratios are compared with quantum chromodynamics-inspired models, tuned to reproduce also the earlier measurements performed at the LHC. Furthermore, the integrated particle yields and ratios as well as the average transverse momenta are compared with results at lower collision energies.

Production of [Formula: see text] and [Formula: see text] in proton-proton collisions at [Formula: see text] 7 TeV

The production of the strange and double-strange baryon resonances ([Formula: see text], [Formula: see text]) has been measured at mid-rapidity ([Formula: see text][Formula: see text]) in proton-proton collisions at [Formula: see text] [Formula: see text] 7 TeV with the ALICE detector at the LHC. Transverse momentum spectra for inelastic collisions are compared to QCD-inspired models, which in general underpredict the data. A search for the [Formula: see text] pentaquark, decaying in the [Formula: see text] channel, has been carried out but no evidence is seen.

Exclusive J/ψ photoproduction off protons in ultraperipheral p-Pb collisions at √(s(NN))=5.02 TeV

We present the first measurement at the LHC of exclusive J/ψ photoproduction off protons, in ultraperipheral proton-lead collisions at sqrt[s_{NN}]=5.02  TeV. Events are selected with a dimuon pair produced either in the rapidity interval, in the laboratory frame, 2.5<y<4 (p-Pb) or -3.6<y<-2.6 (Pb-p), and no other particles observed in the ALICE acceptance. The measured cross sections σ(γ+p→J/ψ+p) are 33.2±2.2(stat)±3.2(syst)±0.7(theor)  nb in p-Pb and 284±36(stat)_{-32}^{+27}(syst)±26(theor)  nb in Pb-p collisions. We measure this process up to about 700 GeV in the γp center of mass, which is a factor of two larger than the highest energy studied at HERA. The data are consistent with a power law dependence of the J/ψ photoproduction cross section in γp energies from about 20 to 700 GeV, or equivalently, from Bjorken x scaling variable between ∼2×10^{-2} and ∼2×10^{-5}, thus indicating no significant change in the gluon density behavior of the proton between HERA and LHC energies.

Measurement of prompt D-meson production in p-Pb collisions at √(s(NN))=5.02 TeV

The p_{T}-differential production cross sections of the prompt charmed mesons D^{0}, D^{+}, D^{*+}, and D_{s}^{+} and their charge conjugate in the rapidity interval -0.96<y_{cms}<0.04 were measured in p-Pb collisions at a center-of-mass energy sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The nuclear modification factor R_{pPb}, quantifying the D-meson yield in p-Pb collisions relative to the yield in pp collisions scaled by the number of binary nucleon-nucleon collisions, is compatible within the 15%-20% uncertainties with unity in the transverse momentum interval 1<p_{T}<24  GeV/c. No significant difference among the R_{pPb} of the four D-meson species is observed. The results are described within uncertainties by theoretical calculations that include initial-state effects. The measurement adds experimental evidence that the modification of the momentum spectrum of D mesons observed in Pb-Pb collisions with respect to pp collisions is due to strong final-state effects induced by hot partonic matter.

Measurement of quarkonium production at forward rapidity in [Formula: see text] collisions at [Formula: see text]TeV

The inclusive production cross sections at forward rapidity of [Formula: see text], [Formula: see text], [Formula: see text](1S) and [Formula: see text](2S) are measured in [Formula: see text] collisions at [Formula: see text] with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.35 pb[Formula: see text]. Quarkonia are reconstructed in the dimuon-decay channel and the signal yields are evaluated by fitting the [Formula: see text] invariant mass distributions. The differential production cross sections are measured as a function of the transverse momentum [Formula: see text] and rapidity [Formula: see text], over the ranges [Formula: see text] GeV/c for [Formula: see text], [Formula: see text] GeV/c for all other resonances and for [Formula: see text]. The measured cross sections integrated over [Formula: see text] and [Formula: see text], and assuming unpolarized quarkonia, are: [Formula: see text] [Formula: see text]b, [Formula: see text] [Formula: see text]b, [Formula: see text] nb and [Formula: see text] nb, where the first uncertainty is statistical and the second one is systematic. The results are compared to measurements performed by other LHC experiments and to theoretical models.

Energy dependence of the transverse momentum distributions of charged particles in pp collisions measured by ALICE

Differential cross sections of charged particles in inelastic pp collisions as a function of p_T have been measured at [Formula: see text] at the LHC. The p_T spectra are compared to NLO-pQCD calculations. Though the differential cross section for an individual [Formula: see text] cannot be described by NLO-pQCD, the relative increase of cross section with [Formula: see text] is in agreement with NLO-pQCD. Based on these measurements and observations, procedures are discussed to construct pp reference spectra at [Formula: see text] up to p_T=50 GeV/c as required for the calculation of the nuclear modification factor in nucleus-nucleus and proton-nucleus collisions.