A joint physics and radiobiology DREAM team vision - Towards better response prediction models to advance radiotherapy

Radiotherapy developed empirically through experience balancing tumour control and normal tissue toxicities. Early simple mathematical models formalized this practical knowledge and enabled effective cancer treatment to date. Remarkable advances in technology, computing, and experimental biology now create opportunities to incorporate this knowledge into enhanced computational models. The ESTRO DREAM (Dose Response, Experiment, Analysis, Modelling) workshop brought together experts across disciplines to pursue the vision of personalized radiotherapy for optimal outcomes through advanced modelling. The ultimate vision is leveraging quantitative models dynamically during therapy to ultimately achieve truly adaptive and biologically guided radiotherapy at the population as well as individual patient-based levels. This requires the generation of models that inform response-based adaptations, individually optimized delivery and enable biological monitoring to provide decision support to clinicians. The goal is expanding to models that can drive the realization of personalized therapy for optimal outcomes. This position paper provides their propositions that describe how innovations in biology, physics, mathematics, and data science including AI could inform models and improve predictions. It consolidates the DREAM team's consensus on scientific priorities and organizational requirements. Scientifically, it stresses the need for rigorous, multifaceted model development, comprehensive validation and clinical applicability and significance. Organizationally, it reinforces the prerequisites of interdisciplinary research and collaboration between physicians, medical physicists, radiobiologists, and computational scientists throughout model development. Solely by a shared understanding of clinical needs, biological mechanisms, and computational methods, more informed models can be created. Future research environment and support must facilitate this integrative method of operation across multiple disciplines.

Prediction of Response to Systemic Corticosteroids in Active UC by Microbial Composition-A Prospective Multicenter Study

BACKGROUND

Corticosteroids are used for induction of remission in patients with moderately to severely active ulcerative colitis. However, up to one-third of patients fail to this therapy. We investigated if fecal microbial composition or its metabolic capacity are associated with response to systemic corticosteroids.

METHODS

In this prospective, multicenter study, patients with active ulcerative colitis (Lichtiger score ≥4) receiving systemic corticosteroids were eligible. Data were assessed and fecal samples collected before and after 4 weeks of treatment. Patients were divided into responders (decrease of Lichtiger Score ≥50%) and nonresponders. The fecal microbiome was assessed by the 16S rRNA gene marker and analyzed with QIIME 2. Microbial metabolic pathways were predicted using parsimonious flux balance analysis.

RESULTS

Among 93 included patients, 69 (74%) patients responded to corticosteroids after 4 weeks. At baseline, responders could not be distinguished from nonresponders by microbial diversity and composition, except for a subgroup of biologic-naïve patients. Within 4 weeks of treatment, responders experienced changes in beta diversity with enrichment of ascribed beneficial taxa, including Blautia, Anaerostipes, and Bifidobacterium, as well as an increase in predicted butyrate synthesis. Nonresponders had only minor longitudinal taxonomic changes with a significant increase of Streptococcus salivarius and a microbial composition shifting away from responders.

CONCLUSION

Baseline microbial diversity and composition seem to be of limited use to predict response to systemic corticosteroids in active ulcerative colitis. Response is longitudinally associated with restoration of microbial composition and its metabolic capacity.

Emergence of liquid following laser melting of gold thin films

X-ray structural science is undergoing a revolution driven by the emergence of X-ray Free-electron Laser (XFEL) facilities. The structures of crystalline solids can now be studied on the picosecond time scale relevant to phonons, atomic vibrations which travel at acoustic velocities. In the work presented here, X-ray diffuse scattering is employed to characterize the time dependence of the liquid phase emerging from femtosecond laser-induced melting of polycrystalline gold thin films using an XFEL. In a previous analysis of Bragg peak profiles, we showed the supersonic disappearance of the solid phase and presented a model of pumped hot electrons carrying energy from the gold surface to scatter at internal grain boundaries. This generates melt fronts propagating relatively slowly into the crystal grains. By conversion of diffuse scattering to a partial X-ray pair distribution function, we demonstrate that it has the characteristic shape obtained by Fourier transformation of the measured F(Q). The diffuse signal fraction increases with a characteristic rise-time of 13 ps, roughly independent of the incident pump fluence and consequent final liquid fraction. This suggests the role of further melt-front nucleation processes beyond grain boundaries.

[Use of subcutaneous Vedolizumab: A position paper issued by the Inflammatory Bowel Disease Working Group of the Austrian Society of Gastroenterology and Hepatology (ÖGGH)]

The humanized monoclonal anti-α4β7-integrin-antibody vedolizumab is one of several biologic therapeutic options in moderate-to-severe ulcerative colitis and Crohn's disease. Within the VISIBLE trial program, a novel subcutaneous application route was evaluated in addition to the already established intravenous form. In this position statement, the working group "Inflammatory Bowel Diseases" of the Austrian Society for Gastroenterology and Hepatology (OEGGH) summarizes the evidence regarding the subcutaneous application of vedolizumab. This work supplements a position paper on the value of vedolizumab as a first-line biologic that has already been published and offers useful recommendations for clinical practice.

Factors Associated with Response to Systemic Corticosteroids in Active Ulcerative Colitis: Results from a Prospective, Multicenter Trial

BACKGROUND

Among patients with ulcerative colitis, 30-50% receive corticosteroids within the first five years after diagnosis. We aimed to reconsider their effectiveness in the context of the biologic era.

METHODS

In this prospective, multicenter study, patients with active ulcerative colitis (Lichtiger score ≥ 4) were eligible if initiating systemic corticosteroids. The primary endpoint was clinical response (decrease in the Lichtiger score of ≥50%) at week 4. Secondary endpoints included combined response defined as clinical response and any reduction in elevated biomarkers (CRP and/or calprotectin). Steroid dependence was assessed after three months.

RESULTS

A total of 103 patients were included. Clinical response was achieved by 73% of patients, and combined response by 68%. A total of 15% of patients were steroid-dependent. Activity of colitis did not influence short-term response to treatment but increased the risk for steroid dependence. Biologic-naïve patients responded better than biologic-experienced patients. Past smoking history (OR 5.38 [1.71, 20.1], p = 0.003), hemoglobin levels (OR 0.76 [0.57, 0.99] for higher levels, p = 0.045), and biologic experience (OR 3.30 [1.08, 10.6], p = 0.036) were independently associated with nonresponse.

CONCLUSION

Disease activity was not associated with short-term response to systemic corticosteroids but was associated with steroid dependence in patients with active ulcerative colitis. Exposure to biologics negatively affects response rates.

Postacute COVID-19 is Characterized by Gut Viral Antigen Persistence in Inflammatory Bowel Diseases

BACKGROUND & AIMS

The coronavirus disease 2019 (COVID-19) pandemic has affected populations, societies, and lives for more than 2 years. Long-term sequelae of COVID-19, collectively termed the postacute COVID-19 syndrome, are rapidly emerging across the globe. Here, we investigated whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen persistence underlies the postacute COVID-19 syndrome.

METHODS

We performed an endoscopy study with 46 patients with inflammatory bowel disease (IBD) 219 days (range, 94-257) after a confirmed COVID-19 infection. SARS-CoV-2 antigen persistence was assessed in the small and large intestine using quantitative polymerase chain reaction of 4 viral transcripts, immunofluorescence of viral nucleocapsid, and virus cultivation from biopsy tissue. Postacute COVID-19 was assessed using a standardized questionnaire, and a systemic SARS-CoV-2 immune response was evaluated using flow cytometry and enzyme-linked immunosorbent assay at endoscopy. IBD activity was evaluated using clinical, biochemical, and endoscopic means.

RESULTS

We report expression of SARS-CoV-2 RNA in the gut mucosa ∼7 months after mild acute COVID-19 in 32 of 46 patients with IBD. Viral nucleocapsid protein persisted in 24 of 46 patients in gut epithelium and CD8+ T cells. Expression of SARS-CoV-2 antigens was not detectable in stool and viral antigen persistence was unrelated to severity of acute COVID-19, immunosuppressive therapy, and gut inflammation. We were unable to culture SARS-CoV-2 from gut tissue of patients with viral antigen persistence. Postacute sequelae of COVID-19 were reported from the majority of patients with viral antigen persistence, but not from patients without viral antigen persistence.

CONCLUSION

Our results indicate that SARS-CoV-2 antigen persistence in infected tissues serves as a basis for postacute COVID-19. The concept that viral antigen persistence instigates immune perturbation and postacute COVID-19 requires validation in controlled clinical trials.

The Treatment Decision-making Preferences of Patients with Prostate Cancer Should Be Recorded in Research and Clinical Routine: a Pooled Analysis of Four Survey Studies with 7169 Patients

Different patients want to take different roles in the treatment decision-making process; these roles can be classified as passive, collaborative, and active. The aim of this study was to investigate the correlation between decision-making preferences among patients with prostate cancer and personal, disease-related, and structural factors. In four survey studies, we asked 7169 prostate cancer patients about their decision-making preferences using the Control Preferences Scale (CPS) and collected clinical, psychological, and quality-of-life measures. Most patients (62.2%) preferred collaborative decision-making, while 2322 (32.4%) preferred an active role, and only 391 (5.5%) preferred a passive role. Age (p < 0.001), data collection mode (p < 0.001), peer-to-peer support (p = 0.018), treatment status (p < 0.001), performed or planned radical prostatectomy (p < 0.001), metastatic disease (p = 0.001), and quality of life (p < 0.001) showed significant associations with patients' preferred decision-making roles. Oncologic risk group, anxiety, and depression were not significant in the model. In particular, younger prostate cancer patients with higher quality of life completing an online survey want to play a more active role in treatment decision-making. Before treatment has started, patients tend to prefer collaborative decision-making. Few prostate cancer patients in Germany prefer a passive role. These patients are mostly older patients, patients with a metastatic disease, and patients who have opted for prostatectomy. Whether this finding reflects a generational effect or a tendency by age group and disease phase should be investigated. Further research is also needed to describe the causalities of these relationships. The CPS offers valuable information for personal counselling and should be applied in clinical routine. In a large group of patients with prostate cancer, we found that there is a strong desire for joint decision-making with the physician before the actual treatment. Especially younger men, men with active online behaviour, and men with a high quality of life want to be actively involved in therapy decision-making processes.

PUFA-Induced Metabolic Enteritis as a Fuel for Crohn's Disease

BACKGROUND & AIMS

Crohn's disease (CD) globally emerges with Westernization of lifestyle and nutritional habits. However, a specific dietary constituent that comprehensively evokes gut inflammation in human inflammatory bowel diseases remains elusive. We aimed to delineate how increased intake of polyunsaturated fatty acids (PUFAs) in a Western diet, known to impart risk for developing CD, affects gut inflammation and disease course. We hypothesized that the unfolded protein response and antioxidative activity of glutathione peroxidase 4 (GPX4), which are compromised in human CD epithelium, compensates for metabolic perturbation evoked by dietary PUFAs.

METHODS

We phenotyped and mechanistically dissected enteritis evoked by a PUFA-enriched Western diet in 2 mouse models exhibiting endoplasmic reticulum (ER) stress consequent to intestinal epithelial cell (IEC)-specific deletion of X-box binding protein 1 (Xbp1) or Gpx4. We translated the findings to human CD epithelial organoids and correlated PUFA intake, as estimated by a dietary questionnaire or stool metabolomics, with clinical disease course in 2 independent CD cohorts.

RESULTS

PUFA excess in a Western diet potently induced ER stress, driving enteritis in Xbp1-/-IEC and Gpx4+/-IEC mice. ω-3 and ω-6 PUFAs activated the epithelial endoplasmic reticulum sensor inositol-requiring enzyme 1α (IRE1α) by toll-like receptor 2 (TLR2) sensing of oxidation-specific epitopes. TLR2-controlled IRE1α activity governed PUFA-induced chemokine production and enteritis. In active human CD, ω-3 and ω-6 PUFAs instigated epithelial chemokine expression, and patients displayed a compatible inflammatory stress signature in the serum. Estimated PUFA intake correlated with clinical and biochemical disease activity in a cohort of 160 CD patients, which was similarly demonstrable in an independent metabolomic stool analysis from 199 CD patients.

CONCLUSIONS

We provide evidence for the concept of PUFA-induced metabolic gut inflammation which may worsen the course of human CD. Our findings provide a basis for targeted nutritional therapy.

An evaluation of the CARL manikin for use in "patient-free" real ear measurement: consistency and comparison to normative data

OBJECTIVE

Simulation-based learning experiences provide low-risk opportunities for procedural training and practice in audiology. A series of real ear measurements (REM) were completed using Clinical Assistant for Research and Learning (CARL) manikins to determine expected responses and to compare to normative data.

DESIGN

(1) Real-ear Unaided Response (REUR) curves were measured with one CARL and each of three ear styles. (2) Test/retest reliability was evaluated by repeating each REUR. (3) Real ear to coupler difference (RECD) values for foam-tip and custom earmolds were calculated. (4) The reliability across copies of the CARL heads was evaluated by comparing REUR measurement from one set of ears on 4 heads.

STUDY SAMPLE

Four adult CARL manikins and thirty ears (5 sets of large, small, and bent).

RESULTS

Within each ear category, the average difference across frequencies from one ear to the next was less than 2.5 dB with no significant individual difference more than 5.8 dB. Test/retest reliability was excellent. Typical REUR and RECD curves were created for each ear style and compared to published data on human ears.

CONCLUSIONS

REM using the adult CARL head are predictable and repeatable making this simulator a good tool for audiological training.

Inflammatory Bowel Disease and Risk of Major Bleeding During Anticoagulation for Venous Thromboembolism

BACKGROUND

Little is known about the bleeding risk in patients with inflammatory bowel disease (IBD) and venous thromboembolism (VTE) treated with anticoagulation. Our aim was to elucidate the rate of major bleeding (MB) events in a well-defined cohort of patients with IBD during anticoagulation after VTE.

METHODS

This study is a retrospective follow-up analysis of a multicenter cohort study investigating the incidence and recurrence rate of VTE in IBD. Data on MB and IBD- and VTE-related parameters were collected via telephone interview and chart review. The objective of the study was to evaluate the impact of anticoagulation for VTE on the risk of MB by comparing time periods with anticoagulation vs those without anticoagulation. A random-effects Poisson regression model was used.

RESULTS

We included 107 patients (52 women, 40 with ulcerative colitis, 64 with Crohn disease, and 3 with unclassified IBD) in the study. The overall observation time was 388 patient-years with and 1445 patient-years without anticoagulation. In total, 23 MB events were registered in 21 patients, among whom 13 MB events occurred without anticoagulation and 10 occurred with anticoagulation. No fatal bleeding during anticoagulation was registered. The incidence rate for MB events was 2.6/100 patient-years during periods exposed to anticoagulation and 0.9/100 patient-years during the unexposed time. Exposure to anticoagulation (adjusted incidence rate ratio, 3.7; 95% confidence interval, 1.5-9.0; P = 0.003) and ulcerative colitis (adjusted incidence rate ratio, 3.5; 95% confidence interval, 1.5-8.1; P = 0.003) were independent risk factors for MB events.

CONCLUSION

The risk of major but not fatal bleeding is increased in patients with IBD during anticoagulation. Our findings indicate that this risk may be outweighed by the high VTE recurrence rate in patients with IBD.

B and T cell response to SARS-CoV-2 vaccination in health care professionals with and without previous COVID-19

Background

In recent months numerous health care professional acquired COVID-19 at the workplace resulting in significant shortages in medical and nursing staff. We investigated how prior COVID-19 affects SARS-CoV-2 vaccination and how such knowledge could facilitate frugal vaccination strategies.

Methods

In a cohort of 41 healthcare professionals with (n=14) and without (n=27) previous SARS-CoV-2 infection, we assessed the immune status before, during and after vaccination with BNT162b2. The humoral immune response was assessed by receptor binding domain ELISA and different SARS-CoV-2 neutralisation assays using wildtype and pseudo-typed viruses. T cell immunity against SARS-CoV-2 surface and nucleocapsid peptides were studied using interferon-γ release assays and intracellular flow cytometry. Vaccine-related side effects were captured.

Findings

Prior COVID-19 resulted in improved vaccine responses both in the B and T cell compartment. In vaccine recipients with prior COVID-19, the first vaccine dose induced high antibody concentrations comparable to seronegative vaccine recipients after two injections. This translated into more efficient neutralisation of virus particles, even more pronounced than expected from the RBD ELISA results. Furthermore, T cell responses were stronger in convalescents and particularly strong against the SARS-CoV-2 nucleocapsid protein.

Interpretation

Herein, we corroborate recent findings suggesting that in convalescents a single vaccine dose is sufficient to boost adequate in vitro neutralisation of SARS-CoV-2 and therefore may be sufficient to induce adequate protection against severe COVID-19. New spike mutated virus variants render the highly conserved nucleocapsid protein – eliciting strong SARS-CoV-2 specific T cell immunity – an interesting additional vaccine target.

Funding

Christian Doppler Research Association, Johannes Kepler University Linz

Prognostic Factors in Open Triangular Fibrocartilage Complex (TFCC) Repair

Purpose

Patients with triangular fibrocartilage complex (TFCC) injury report ulnar-sided wrist pain and impaired function. Open TFCC repair aims to improve the condition of these patients. Patients have shown reduction in pain and improvement in function at 12 months after surgery; however, results are highly variable. The purpose of this study was to relate patient (eg, age and sex), disease (eg, trauma history and arthroscopic findings), and surgery factors (type of bone anchor) associated with pain and functional outcomes at 12 months after surgery.

Methods

This study included patients who underwent an open TFCC repair between December 2011 and December 2018 in various Xpert Clinics in the Netherlands. All patients were asked to complete Patient-Rated Wrist Evaluation (PRWE) questionnaires at baseline as well as at 12 months after surgery. Patient, disease, and surgery factors were extracted from digital patient records. All factors were analyzed by performing a multivariable hierarchical linear regression.

Results

We included 274 patients who had received open TFCC repair and completed PRWE questionnaires. Every extra month of symptoms before surgery was correlated with an increase of 0.14 points on the PRWE total score at 12 months after surgery. In addition, an increase of 0.28 points in the PRWE total score at 12 months was seen per extra point of PRWE total score at baseline.

Conclusions

Increased preoperative pain, less preoperative function, and a longer duration of complaints are factors that were associated with more pain and less function at 12 months after open surgery for TFCC. This study arms surgeons with data to predict outcomes for patients undergoing open TFCC repair.

Type of study/level of evidence

Prognostic II.

Use of complementary and alternative medicine and low quality of life associate with the need for psychological and psychotherapeutic interventions in inflammatory bowel disease

Introduction

Patients with inflammatory bowel disease (IBD) suffer from various symptoms, impairing their quality of life and often affecting psychosocial issues. This may lead to the need for additional psychological care. This study investigated patients' subjective need for integrated psychosomatic support and psychotherapy and indicators for it.

Materials and methods

This is a cross‐sectional multicentre study in Austrian IBD patients who were in routine care at 18 IBD outpatient clinics. Patients filled in an anonymous, validated questionnaire (Assessment of the Demand for Additional Psychological Treatment Questionnaire [ADAPT]) assessing the need for psychological care. The ADAPT gives two separate scores: the need for integrated psychosomatic support and for psychotherapy. In addition, health‐related quality of life and the use of complementary and alternative medicine as well as clinical and socio‐demographic variables were queried. Multivariable regression analysis was performed to estimate the effect of the previously mentioned variables on the need for additional psychological care.

Results

Of 1286 patients, 29.7% expressed a need for additional psychological care, 19.6% expressed a need for integrated psychosomatic support and 20.2% expressed a need for psychotherapy. In the multivariable analysis, the two strongest indicators for the need for both types of psychological care were the use of complementary and alternative medicine (for integrated psychosomatic support: odds ratio = 1.64, 95% confidence interval 1.13–2.39, p = 0.010; for psychotherapy: odds ratio = 1.74, 95% confidence interval 1.20–2.53, p = 0.004), and a low health‐related quality of life score (for integrated psychosomatic support: odds ratio = 0.95, 95% confidence interval 0.94–0.96, p < 0.001; for psychotherapy: odds ratio = 0.96, 95% confidence interval 0.94–0.97, p < 0.001).

Discussion

About 30% of the Austrian IBD patients expressed a need for integrated psychosomatic support and/or psychotherapy. The most important indicators for this need were the use of complementary and alternative medicine and low quality of life.

What is already known?

Despite ongoing improvement of treatment options, patients may not respond to treatment or may develop side effects. Due to this burden of disease, patients may also suffer from psychological symptoms, such as depression

In our previous study in 2008, we found that 31% of patients with inflammatory bowel disease (IBD) expressed a subjective need for psychological interventions

What are the significant and/or new findings of the study?

Despite improvements in therapy, around 30% of patients with IBD express a subjective need for psychological interventions

This subjective need for psychological interventions is associated with complementary and alternative medicine use and low quality of life

Microbial Butyrate Synthesis Indicates Therapeutic Efficacy of Azathioprine in IBD Patients

BACKGROUND AND AIMS

The microbial ecosystem seems to be an important player for therapeutic intervenption in inflammatory bowel disease [IBD]. We assessed longitudinal microbiome changes in IBD patients undergoing therapy with either azathioprine [AZA] or anti-tumour necrosis factor [anti-TNF] antibodies. We predicted the metabolic microbial community exchange and linked it to clinical outcome.

METHODS

Faecal and blood samples were collected from 65 IBD patients at baseline and after 12 and 30 weeks on therapy. Clinical remission was defined as Crohn's Disease Activity Index [CDAI] < 150 in Crohn´s disease [CD], partial Mayo score <2 in ulcerative colitis [UC], and faecal calprotectin values <150 µg/g and C-reactive protein <5 mg/dl. 16S rRNA amplicon sequencing was performed. To predict microbial community metabolic processes, we constructed multispecies genome-scale metabolic network models.

RESULTS

Paired Bray-Curtis distance between baseline and follow-up time points was significantly different for UC patients treated with anti-TNF antibodies. Longitudinal changes in taxa composition at phylum level showed a significant decrease of Proteobacteria and an increase of Bacteroidetes in CD patients responding to both therapies. At family level, Lactobacilli were associated with persistent disease and Bacteroides abundance with remission in CD. In-silico simulations of microbial metabolite exchange predicted a 1.7-fold higher butyrate production capacity of patients in remission compared with patients without remission [p = 0.041]. In this model, the difference in butyrate production between patients in remission and patients without remission was most pronounced in the CD group treated with AZA [p = 0.008].

CONCLUSIONS

In-silico simulation identifies microbial butyrate synthesis predictive of therapeutic efficacy in IBD.

Faecal Biomarkers in Inflammatory Bowel Diseases: Calprotectin Versus Lipocalin-2-a Comparative Study

BACKGROUND AND AIMS

Faecal biomarkers, particularly calprotectin [FCAL], have become important diagnostic and monitoring tools in inflammatory bowel diseases [IBD]. As FCAL is mainly produced by neutrophils, we hypothesised that faecal lipocalin-2 [FLCN2], also expressed by intestinal epithelial cells [IEC], could be beneficial in specific clinical situations.

METHODS

We compared clinical and endoscopic activity-related correlations between FCAL and FLCN2, assayed from the same sample, in a cohort of 132 patients (72 Crohn's disease [CD]) and 40 controls. A detailed analysis of cellular origins was done by confocal microscopy and flow cytometry. To evaluate the potential to detect low-grade inflammation, we studied faecal and tissue concentrations in a cohort with clinical, endoscopic, and histological remission.

RESULTS

There was an excellent correlation between FCAL and FLCN2 [rS = 0.87, p <0.001] and comparable sensitivity and specificity to predict clinical and endoscopic disease activity, with optimal thresholds for endoscopic activity of 73.4 and 1.98 µg/g in ulcerative colitis [UC] and 78.4 and 0.56 µg/g in Crohn's disease for FCAL and FLCN2, respectively. Strong co-expression of both proteins was observed in granulocytes and macrophages. IECs expressed LCN2 but not CAL. In our IBD cohort in deep remission neither FCAL nor FLCN2 was different from controls; yet mucosal LCN2 but not CAL expressions remained elevated in the rectum of UC and the ileum of CD patients.

CONCLUSIONS

This study corroborates the diagnostic equivalence of FLCN2 and FCAL in IBD. In remission, persistent mucosal overexpression renders LCN2 an attractive candidate for molecular inflammation warranting further investigation.

Generation of an iPSC line (UMGWi001-B) from a patient with Floating-Harbor Syndrome (FLHS) carrying a heterozygous SRCAP mutation (p.Arg2444)

Floating-Harbor syndrome (FLHS) is a rare genetic disease caused by mutations in the SRCAP gene. Here, we generated an induced pluripotent stem cell line from gingival fibroblasts of a male patient with a heterozygous mutation in exon 34 of the SRCAP gene (c.7330C > T, p.Arg2444*). The iPSC colonies have an atypical morphology with diffuse borders and disintegrate quickly upon touch. Still, the cell line expresses pluripotency markers and differentiates into three germ layers. The cell line can be used as patient-specific disease model and help elucidate the molecular mechanisms involving SRCAP in the context of FLHS.

Liquid compound refractive X-ray lens

We introduce the concept of a liquid compound refractive X-ray zoom lens. The lens is generated by pumping a suitable liquid lens material like water, alcohol or heated lithium through a line of nozzles each forming a jet with the cross section of lens elements. The system is housed, so there is a liquid-circulation. This lens can be used in white beam at high brilliance synchrotron sources, as radiation damages are cured by the continuous reformation of the lens. The focal length can be varied by closing nozzles, thus reducing the number of lens elements in the beam.

Dietary lipids fuel GPX4-restricted enteritis resembling Crohn's disease

The increased incidence of inflammatory bowel disease (IBD) has become a global phenomenon that could be related to adoption of a Western life-style. Westernization of dietary habits is partly characterized by enrichment with the ω-6 polyunsaturated fatty acid (PUFA) arachidonic acid (AA), which entails risk for developing IBD. Glutathione peroxidase 4 (GPX4) protects against lipid peroxidation (LPO) and cell death termed ferroptosis. We report that small intestinal epithelial cells (IECs) in Crohn’s disease (CD) exhibit impaired GPX4 activity and signs of LPO. PUFAs and specifically AA trigger a cytokine response of IECs which is restricted by GPX4. While GPX4 does not control AA metabolism, cytokine production is governed by similar mechanisms as ferroptosis. A PUFA-enriched Western diet triggers focal granuloma-like neutrophilic enteritis in mice that lack one allele of Gpx4 in IECs. Our study identifies dietary PUFAs as a trigger of GPX4-restricted mucosal inflammation phenocopying aspects of human CD.

Dietary lipids are linked to the development of inflammatory bowel diseases through unclear mechanisms. Here, the authors report that dietary polyunsaturated fatty acids trigger intestinal inflammation resembling aspects of Crohn’s disease, which is restricted by glutathione peroxidase 4 in the intestinal epithelium.

[Neuroendocrine tumors in daily gastroenterology and endoscopy - a practice manual]

Neuroendocrine tumors of the gastrointestinal tract (GI-NET) are rare tumors. Functional tumors with hormonal syndromes (e. g., insulinoma, gastrinoma) are less common than non-functional tumors, which usually have an indolent course. Therapy for GI-NET is multimodal, including endoscopic or surgical procedures aiming at complete removal of tumor tissue. Patients in later stages may benefit from interventional radiology or medical therapy. This article gives an overview regarding the key aspects of GI-NET therapy in daily gastroenterology practice with emphasis on endoscopic diagnosis and therapy.

Thermally induced transformations of Au@Cu2O core–shell nanoparticles into Au–Cu nanoparticles from temperature-programmed in situ powder X-ray diffraction

Temperature-programmed in situ X-ray diffraction with whole-powder-pattern modeling is used to investigate the reaction of Au@Cu2O core–shell nanoparticles to form nanocrystalline bimetallic Cu x Au1−x alloys (x = 0, 0.25, 0.5, 0.75, 1.0) in a reducing atmosphere. The mechanisms of the reactions are key to informed design of tailored non-equilibrium nanostructures for catalytic and plasmonic materials. The Au@Cu2O reaction is initiated by reduction of the Cu2O cuprite shell to form nanocrystalline metallic Cu at about 413 K. Alloying begins immediately upon formation of metallic Cu at 413 K, with the nucleation of an Au-rich alloy phase which reaches the nominal Cu content of the overall system stoichiometry by 493 K. All bimetallic alloys form a transient ordered Cu3Au intermetallic compound at intermediate temperatures, with the onset of ordering and subsequent disordering varying by composition. No evidence for an ordered Au3Cu intermetallic is found for any composition. Significant crystal growth in the bimetallic phase is apparent at higher temperatures, with the onset temperature increasing with Cu concentration and initial Cu-shell thickness. The reduction of the cuprite phase is slowed by the presence of the core–shell interface, and crystal growth in the Cu shell is completely suppressed within the alloy systems.

Diagnostic delay in patients with inflammatory bowel disease in Austria

BACKGROUND

Delayed diagnosis seems to be common in inflammatory bowel diseases (IBD). The study was carried out to investigate the diagnostic delay and associated risk factors in Austrian IBD patients.

METHODS

In a multicenter cross-sectional study adult patients with IBD attending 18 Austrian outpatient clinics completed a multi-item questionnaire that recorded medical and socioeconomic characteristics. The study outcome was diagnostic delay defined as the period from symptom onset to diagnosis of IBD.

RESULTS

A total of 1286 patients (Crohn's disease 830, ulcerative colitis 435, inflammatory bowel disease unclassified 21; females 651) with a median age of 40 years (interquartile range 31-52 years) and a median disease duration of 10 years (4-18 years) were analyzed. The median diagnostic delay was 6 months (2-23 months) in Crohn's disease and 3 months (1-10 months) in ulcerative colitis (p < 0.001). In the multivariable regression analysis Crohn's disease, greater age at diagnosis and a high educational level (compared to middle degree level) were independently associated with longer diagnostic delay.

CONCLUSION

The diagnostic delay was longer in Crohn's disease than in ulcerative colitis patients and was associated with greater age at diagnosis and a higher educational level.

Immunosuppressives and biologics during pregnancy and lactation : A consensus report issued by the Austrian Societies of Gastroenterology and Hepatology and Rheumatology and Rehabilitation

An increasing and early-onset use of immunosuppressives and biologics has become more frequently seen among patients with inflammatory bowel diseases (IBD) and rheumatic disorders. Many women in their childbearing years currently receive such medications, and some of them in an interdisciplinary setting. Many questions arise in women already pregnant or wishing to conceive with respect to continuing or discontinuing treatment, the risks borne by the newborns and their mothers and long-term safety. Together with the Austrian Society of Rheumatology and Rehabilitation, the IBD working group of the Austrian Society of Gastroenterology and Hepatology has elaborated consensus statements on the use of immunosuppressives and biologics in pregnancy and lactation. This is the first Austrian interdisciplinary consensus on this topic. It is intended to serve as a basis and support for providing advice to our patients and their treating physicians.

Effect of Periodontal Treatment on HbA1c among Patients with Prediabetes

Evidence is limited regarding whether periodontal treatment improves hemoglobin A1c (HbA1c) among people with prediabetes and periodontal disease, and it is unknown whether improvement of metabolic status persists >3 mo. In an exploratory post hoc analysis of the multicenter randomized controlled trial “Antibiotika und Parodontitis” (Antibiotics and Periodontitis)—a prospective, stratified, double-blind study—we assessed whether nonsurgical periodontal treatment with or without an adjunctive systemic antibiotic treatment affects HbA1c and high-sensitivity C-reactive protein (hsCRP) levels among periodontitis patients with normal HbA1c (≤5.7%, n = 218), prediabetes (5.7% < HbA1c < 6.5%, n = 101), or unknown diabetes (HbA1c ≥ 6.5%, n = 8) over a period of 27.5 mo. Nonsurgical periodontal treatment reduced mean pocket probing depth by >1 mm in both groups. In the normal HbA1c group, HbA1c values remained unchanged at 5.0% (95% CI, 4.9% to 6.1%) during the observation period. Among periodontitis patients with prediabetes, HbA1c decreased from 5.9% (95% CI, 5.9% to 6.0%) to 5.4% (95% CI, 5.3% to 5.5%) at 15.5 mo and increased to 5.6% (95% CI, 5.4% to 5.7%) after 27.5 mo. At 27.5 mo, 46% of periodontitis patients with prediabetes had normal HbA1c levels, whereas 47.9% remained unchanged and 6.3% progressed to diabetes. Median hsCRP values were reduced in the normal HbA1c and prediabetes groups from 1.2 and 1.4 mg/L to 0.7 and 0.7 mg/L, respectively. Nonsurgical periodontal treatment may improve blood glucose values among periodontitis patients with prediabetes (ClinicalTrials.gov NCT00707369).

Nanodomains and local structure in ternary alkaline-earth hexaborides

The local structures of ternary alkaline-earth hexaborides (MB6, M = Ca0.5Sr0.5, Ca0.5Ba0.5 and Sr0.5Ba0.5) have been analysed using X-ray pair distribution function (PDF) analysis, Raman spectroscopy and transmission electron microscopy (TEM). The results show significant local deviations from the average cubic structure within the boron sub-lattice and support the conclusion that rapid synthesis processes lead to the formation of coherent nanodomains over length scales of about 10 nm. Reverse Monte Carlo fitting of the PDFs allows for quantification of the displacement disorder within the boron sub-lattice as a function of sample composition. Detailed Raman spectroscopy studies and high-resolution TEM support the models derived from X-ray scattering. The average magnitude of the static displacement disorder varies by sample composition and positively correlates with the cation radius ratios across the three compositions. The new models form a foundation for future computational and experimental studies aimed at understanding and predicting properties of hexaborides.

Differential evolution and Markov chain Monte Carlo analyses of layer disorder in nanosheet ensembles using total scattering

Assemblies of nanosheets are often characterized by extensive layer-position disorder. Coupled with the often minute coherent scattering domain size and relaxation of the nanosheet structure itself, unambiguous interpretation of X-ray and neutron scattering data from such materials is non-trivial. This work demonstrates a general approach towards refinement of layer-disorder information from atomic pair distribution function (PDF) data for materials that span the gap between turbostratism and ordered stacking arrangements. X-ray total scattering data typical of a modern rapid-acquisition PDF instrument are simulated for a hypothetical graphene-like structure using the program DIFFaX, from which atomic PDFs are extracted. Small 1 × 1 × 20 supercell models representing the stacking of discrete layer types are combined to model a continuous distribution of layer-position disorder. Models optimized using the differential evolution algorithm demonstrate improved fit quality over 75 Å when a single mean layer-type model is replaced with a constrained 31-layer-type model. Posterior distribution analyses using the Markov chain Monte Carlo algorithm demonstrate that the influence of layer disorder and finite particle size are correlated. However, the refined mean stacking vectors match well with the generative parameter set.

Identifying On-Surface Site-Selective Chemical Conversions by Theory-Aided NEXAFS Spectroscopy: The Case of Free-Base Corroles on Ag(111)

We demonstrate here that theory-assisted near-edge X-ray absorption fine-structure (NEXAFS) spectroscopy enables the site-sensitive monitoring of on-surface chemical reactions, thus, providing information not accessible by other techniques. As a prototype example, we have used free-base 5,10,15-tris(pentafluorophenyl)corroles (3H-TpFPC) adsorbed on Ag(111) and present a detailed investigation of the angle-dependent NEXAFS of this molecular species as well as of their thermally induced derivatives. For this, we have recorded experimental C and N K-edge NEXAFS spectra and interpret them based on XAS cross-section calculations by using a continuous fraction approach and core-hole including multiprojector PAW pseudopotentials within DFT. We have characterized the as-deposited low temperature (200 K) phase and unraveled the subsequent changes induced by dehydrogenation (at 330 K) and ring-closure reactions (at 430 K). By exemplarily obtaining profound insight into the on-surface chemistry of free-base corrolic species adsorbed on a noble metal this work highlights how angle-dependent XAS combined with accurate theoretical modeling can serve for the investigation of on-surface reactions, whereby even highly similar molecular structures, such as tautomers and isomers, can be distinguished.

Measurement of thyrotropin receptor antibodies (TRAK) with a second generation assay in patients with Graves’ disease

Aim: The detection of TSH-receptor-antibodies (TRAb) in patients (pts) with Graves’ disease (GD) is routinely used in nuclear medicine laboratories. It is performed by commercial, porcine radioreceptorassays (RRA) measuring TSH binding inhibitory activity. A second generation assay using the human, recombinant TSHreceptor was developed during the last years. The manufacturer composed this new assay as a coated tube RRA (CT RRA) and claimed a higher sensitivity for GD. Methods: TRAb was measured in 207 pts with various thyroid disorders and 205 healthy controls using the new coated tube RRA (Fa. B.R.A.H.M.S. Diagnostica GmbH, Berlin, Germany) as well as a conventional RRA (Fa. Medipan Diagnostica GmbH, Selchow, Germany): 60 pts suffering from GD showing a relapse after antithyroid drug treatment and before radioiodine therapy, 109 pts with disseminated autonomia (DA) and 38 pts suffering from Hashimoto’s thyroiditis. A ROC-analysis was performed to find the optimal decision threshold level for positivity. Results: We found 42/60 TRAbpositive pts with GD in the established RRA (threshold 6 U/L) and 52/60 in the CT RRA, respectively. The sensitivity increased from 70% (RRA) to 86,7% (CT RRA). The CT RRA found 2 false positives (one Hashimoto’s and one healthy control) and the RRA detected 3 Hashimoto’s and 2 healthy controls as false positive. Conclusion: The increased sensitivity of CT RRA for GD provides an advantage compared to conventional RRA, especially in GD-patients relapsing after antithyroid drug treatment. Functional sensitivity and Interassayvariation of CT RRA are very precisely compared to conventional RRA. Handling of the new assay is also improved.

Comparison of Rhenium-188, Rhenium-186-HEDP and Strontium-89 in palliation of painful bone metastases

Aim: Several radiopharmaceuticals were compared previously with regard to the efficiency in pain palliation of bone metastases. Furthermore, first results were reported on the suitability for such kind of therapy of the generator produced radionuclide rhenium-188. Method: Influence of Rhenium-188-HEDP (Re-188), Rhenium-186-HEDP (Re-186) and Strontium-89 (Sr-89) on pain symptoms and bone marrow function were obtained in 44 patients (pts). These were 16 pts. with Re-188 (2943 ± 609 MBq), 13 pts. with Re-186 (1341 ± 161 MBq) and 15 pts. with Sr-89 (152 ±18 MBq) (6 woman with breast cancer and 38 mens with prostata cancer). Results: 81 of pts. after Re-188,77% after Re-186 and 80 % after Sr-89 reported relief of pain. The Karnofsky-lndex established by pts. increased from 74 ± 9% to 85 ± 11 % after Re-188, from 70 ± 1 1 % to 76 ± 1 1 % after Re-186 and from 62 ± 10% to 69 ± 10% after Sr-89. However, the difference between the pre- and the post-therapeutic value is only statistically significant in the case of Re-188 therapy (p = 0.001 ). A decrease of platelets of 30 ± 14% after 2.8 ± 0.7 for pts. treated with Re-188, of 39 ± 20% after 3.7 ± 1.0 weeks for pts. treated with Re-186 and of 34 ± 26% after 4.4 ± 1.0 weeks for pts. treated with Sr-89 compared to the value before therapy was observed. The difference was not significant between the 3 groups of pts. (p= 0.125 to 0.862). Conclusion: All tried radiopharmaceuticals were effective in pain palliation. The various radionuclides had no significant difference in the pain relief or the bone marrow impairment. If only the Karnofsky-lndex after Re-188 HEDP seems to be a little more increase.

Where does subclinical hypothyroidism start?

The upper limit of the TSH reference range is currently under discussion. In its recent guidelines, the National Academy of Clinical Biochemistry (NACB) recommended the use of ~2.5 mIU/L, rather than ~4 mIU/L, due to the fact that reference populations, on which the definition of the reference range is based, contain persons undergoing an initial phase of autoimmune thyroid disease. This will skew the upper reference limit of TSH. Ultrasonography, in addition to measurement of thyroid autoantibodies, should be used to exclude these persons. Objective: The present study investigates whether the NACB recommendation also applies for a region of mild iodine deficiency. Methods: According to NACB criteria, a reference population (713 persons) was defined out of a total study population of 1442. The TSH reference range was calculated in this reference group and in further subgroups by percentiles. The results were compared with the total study population and the NACB recommendation. All assays used were provided by BRAHMS Diagnostica AG, Hennigsdorf, Germany. Results: As expected, all median TSH values, excluding the median of the group with a hypoechogenic thyroid were close to 1.2 mIU/L. The 97.5th percentile in the reference population was 3.35 mIU/L. However, there was no difference compared to the total study population. Conclusion: The upper reference limit for TSH based on a reference population according to NACB criteria came down to 3.35 mIU/L, but not to ~2.5 mIU/L. Interestingly, there is no difference compared to the total study population.

Predictive value of thyrotropin receptor antibodies using the second generation TRAb human assay after radioiodine treatment in Graves’ disease

The detection of TSH-receptor antibodies (TRAb) in patients with Graves’ disease is routinely used in nuclear medicine laboratories. This determination has been possible for approximately 3 years with a second generation human TRAb assay. Studies showed that this TRAb determination is diagnostically more sensitive compared to established, porcine TRAb assays. Objective: The aim of our study was to investigate, based on a ROC analysis, whether TRAb determination with the new, second generation assay allows a dependable statement about probability of occurence of relapse after radioiodine therapy in patient suffering from Graves’ disease. Methods: 57 patients were examined with the DYNOtest® TRAKhuman (BRAHMS Diagnostica AG, Hennigsdorf) directly before and six months after therapy with radioiodine (dose: 150 Gy). A ROC-analysis was performed to determine positive/negative predictive values depending on different cut-off values. Results: Whereas 21/57 patients became eu- or hypothyroid after six months, 36/57 patients relapsed. Nonrelapsed patients showed a significant lower median TRAb titer (4.2 IU/l vs. 19.2 IU/l; p <0.05) compared to relapsed patients. But the positive predictive value conducted 63 and 66, 62 and 66 as well as 63 and 69% (before and after therapy) linked with the cut-offs 1.0, 1.5, and 2.0 IU/l. So it was in areas also achieved by the first generation porcine radioreceptorassay. Conclusion: An increased sensitivity is achieved undoubtedly with the new DYNOtest® TRAKhuman in the diagnostic of Graves’ disease. It is not held over the established radioreceptorassay concerning the positive predictive value for relapsing patients.

Recovery-test or immunoradiometric measurement of anti-thyroglobulinautoantibodies

The determination of thyroglobulin (Tg) in the follow-up of differentiated thyroid carcinomas (DTC), is routinely used in nuclear medicine, although some problems, like a disturbed recovery-test (RT) or autoantibodies to thyroglobulin (TgAb), are well known. But it is a controversial issue in literature, whether the determination of TgAb should be performed beside or instead of the RT. Objective: The study compares the clinical value of the determination of both TgAb and RT with sensitive assays. Methods: 356 patients (pts) were investigated. The results were compared to the concentration of Tg in the sera of the pts. 288 pts stayed tumor-free, the remaining 68 pts showed a recurrence (local and/or metastatic) of their DTC. We measured Tg (with RT) using an immunoradiometric assay (Tg-IRMA; SELco® Tg; Fa. Medipan Diagnostica GmbH) and TgAb using a direct assay (CentAK® anti-Tg; also from Fa. Medipan). Results: The prevalence of TgAb, and of disturbed RT respectively, in the whole population of DTC-pts was 7,6%, in the subgroup of tumor-free pts 6,6%, and in the remaining pts with tumor-recurrence 11,8%, respectively 2,0%, 1,7% and 2,9%. In a significantly higher percentage of pts with local/metastatic recurrence, both a positive TgAb (p <0,001) and a disturbed RT (p <0,05) were found. 7/68 pts with tumor-recurrence but Tg <1 ng/ml showed positive TgAb, only 2/7 had a disturbed RT. In this group, no patient with Tg >1 ng/ ml demonstrated either positive TgAb or disturbed RT (p <0,001 and p <0,05). Conclusion: The determination of TgAb in the follow-up of DTC is necessary, because it supports a suspicion to tumor-recurrence in pts with negative Tg. Also the RT is of great value because of a possibly High dose hook-effect.

Der Einfluß verschiedener Strahlenschutzstoffe auf die Strahlenempfindlichkeit von Tumoren

Es wurde der Einfluß von Cysteamin, Serotonin, Nikotinsäureamid, Thioharnstoff, d-Penicillamin und 5-Mercaptopyridoxin auf die Strahlenempfindlichkeit von Tumorgewebe in vitro und in vivo geprüft. Die Untersuchungen erfolgten mit Ehrlich-Aszitestumor, solidem Ehrlich-Karzinom und dem Crocker-Sarkom 180. Im Falle des Ehrlich-Aszites bewirkten nur Cysteamin, Serotonin und Nikotinsäureamid einen Strahlenschutzeffekt. Im Falle des soliden Ehrlich-Karzinoms dagegen konnten gesicherte Schutzeffekte nach Cysteamin, Serotonin, d-Penicillamin und 5-Mercaptopyridoxin gesehen werden. In denselben Untersuchungen mit Crocker-Sarkom war keine der Substanzen in der Lage, einen Schutzeffekt am in vivo bestrahlten Tumor hervorzurufen.