Linking pesticide exposure to neurodegenerative diseases: An in vitro investigation with human neuroblastoma cells

Although many organochlorine pesticides (OCPs) have been banned or restricted because of their persistence and linkage to neurodegenerative diseases, there is evidence of continued human exposure. In contrast, registered herbicides are reported to have a moderate to low level of toxicity; however, there is little information regarding their toxicity to humans or their combined effects with OCPs. This study aimed to characterize the mechanism of toxicity of banned OCP insecticides (aldrin, dieldrin, heptachlor, and lindane) and registered herbicides (trifluralin, triallate, and clopyralid) detected at a legacy contaminated pesticide manufacturing and packing site using SH-SY5Y cells. Cell viability, LDH release, production of reactive oxygen species (ROS), and caspase 3/7 activity were evaluated following 24 h of exposure to the biocides. In addition, RNASeq was conducted at sublethal concentrations to investigate potential mechanisms involved in cellular toxicity. Our findings suggested that aldrin and heptachlor were the most toxic, while dieldrin, lindane, trifluralin, and triallate exhibited moderate toxicity, and clopyralid was not toxic to SH-SY5Y cells. While aldrin and heptachlor induced their toxicity through damage to the cell membrane, the toxicity of dieldrin was partially attributed to necrosis and apoptosis. Moreover, toxic effects of lindane, trifluralin, and triallate, at least partially, were associated with ROS generation. Gene expression profiles suggested that decreased cell viability induced by most of the tested biocides was related to inhibited cell proliferation. The dysregulation of genes encoding for proteins with anti-apoptotic properties also supported the absence of caspase activation. Identified enriched terms showed that OCP toxicity in SH-SY5Y cells was mediated through pathways associated with the pathogenesis of neurodegenerative diseases. In conclusion, this study provides a basis for elucidating the molecular mechanisms of pesticide-induced neurotoxicity. Moreover, it introduced SH-SY5Y cells as a relevant in vitro model for investigating the neurotoxicity of pesticides in humans.

Abdominal ultrasound in head and neck squamous cell carcinoma staging: yes or no?

PURPOSE

Abdominal ultrasound is a diagnostic staging procedure for distant metastases in head and neck squamous cell carcinoma (HNSCC). However, currently performed abdominal staging procedures do not follow consistent standards. Therefore, this retrospective study on 498 patients aimed at investigating on abdominal ultrasound as a staging procedure in HNSCC.

MATERIALS AND METHODS

A retrospective analysis of 498 head and neck cancer patients treated in our Department of Head and Neck Surgery between 2008 and 2015 was performed. Disease-related data were collected over a mean follow-up time of 30.3 months, and results of abdominal ultrasound were analyzed.

RESULTS

426 patients received abdominal ultrasound as a staging procedure. 7% (29) were suspicious for metastases. In 19 cases (66%), the detected abnormalities were masses of the liver. In four patients, abdominal metastases were confirmed at the time of initial diagnosis. 16 patients developed abdominal metastases in the course of the disease (on average 623 days after initial diagnosis). 19 out of 20 patients with abdominal metastases had an N2/N3 cervical lymph node status. In this study, the negative predictive value of abdominal ultrasound for HNSCC staging was 99.03%, while the positive predictive value yielded 5.88% (N2/N3-patients).

CONCLUSION

Only in patients with locally advanced lymph-node-status (N2/N3), abdominal ultrasound can be useful as a staging investigation to exclude abdominal metastasis in HNSCC patients. For N0/N1 patients, abdominal ultrasound might be dispensed. Of note, in case of a positive result, further diagnostic procedures are mandatory.

Computed tomography with adjusted dose for body mass index may be superior to whole-body radiography especially in elderly patients with multiple myeloma

BACKGROUND

Whole-body skeletal radiography has traditionally been used in the management of multiple myeloma for defining treatment strategies. For several reasons, radiography has been replaced by computed tomography (CT) covering the same regions.

PURPOSE

To evaluate the body mass index (BMI) adjusted effective radiation dose from two different methods of whole-body radiologic imaging for multiple myeloma assessment.

MATERIAL AND METHODS

The current investigation analyses the dose to patients resulting from the two methods, conventional radiography supplemented with tomosynthesis (203 examinations) and CT (264 examinations). All patients subject to myeloma staging for 4.5 years were included in the study. Exposure parameters were collected from the PACS and conversion factors were calculated using the software packages PCXMC and VirtualDose enabling the calculation of the effective dose to each patient based on BMI. The Mann-Whitney U test was used for comparisons between groups.

RESULTS

Patients were subject to a median effective dose of 2.5 mSv for conventional radiography and 5.1 mSv for CT, a statistically significant difference.

CONCLUSION

The effective dose for whole-body CT in assessing multiple myeloma is twice as high as for whole-body skeletal survey with modern digital radiography, but at a low level and considerably less than the levels quoted in the earlier studies of ∼30 mSv when the technique was first explored.

Target Organ Toxicity in Rats After Subchronic Oral Exposure to Soil Extracts Containing a Complex Mixture of Contaminants

Complex mixtures of unknown contaminants present a challenge to identify toxicological risks without using large numbers of animals and labor-intensive screens of all organs. This study examined soil extracts from a legacy-contaminated pesticide packaging and blending site. HepG2 cytotoxicity was used as an initial screen of 18 soil samples; then, three extracts (A, B and C) from different locations at the study site were used for testing in animals. The first two extracts were identified as the most toxic in vitro, and the latter extract obtained from a location further from these two toxic sampling sites. Then, target organ toxicities were identified following biweekly oral gavage for one month of three soil extracts (0.1% in polyethylene glycol or PEG) compared to vehicle control in male Sprague-Dawley rats (n = 9-10/group). Exposure to extract A significantly increased neutrophils and lymphocytes compared to control. In contrast, all extracts increased plasma α-2 macroglobulin and caused mild-to-moderate lymphocytic proliferation within the spleen white pulp, all indicative of inflammation. Rats exposed to all soil extracts exhibited acute tubular necrosis. Cholinesterase activity was significantly reduced in plasma, but not brain, after exposure to extract A compared to control. Increased hepatic ethoxyresorufin-o-deethylase activity compared to control was observed following exposure to extracts A and B. Exposure to soil extract C in rats showed a prolonged QTc interval in electrocardiography as well as increased brain lipid peroxidation. Candidate contaminants are organochlorine, organophosphate/carbamate pesticides or metabolites. Overall, HepG2 cytotoxicity did not successfully predict the neurotoxicity and cardiotoxicity observed with extract C but was more successful with suspected hydrocarbon toxicities in extracts A and B. Caution should be taken when extrapolating the observation of no effects from in vitro cell culture to in vivo toxicity, and better cell culture lines or assays should be explored.

Impact of myocardial injury on regional left ventricular function in the course of acute myocarditis with preserved ejection fraction: insights from segmental feature tracking strain analysis using cine cardiac MRI

The aim of this study was to provide insights into myocardial adaptation over time in myocyte injury caused by acute myocarditis with preserved ejection fraction. The effect of myocardial injury, as defined by the presence of late gadolinium enhancement (LGE), on the change of left ventricular (LV) segmental strain parameters was evaluated in a longitudinal analysis. Patients with a first episode of acute myocarditis were enrolled retrospectively. Peak radial (PRS), longitudinal (PLS) and circumferential (PCS) LV segmental strain values at baseline and at follow-up were computed using feature tracking cine cardiac magnetic resonance imaging. The change of segmental strain values in LGE positive (LGE+) and LGE negative (LGE-) segments was compared over a course of 89 ± 20 days. In 24 patients, 100 LGE+ segments and 284 LGE- segments were analysed. Between LGE+ and LGE- segments, significant differences were found for the change of segmental PCS (p < 0.001) and segmental PRS (p = 0.006). LGE + segments showed an increase in contractility, indicating recovery, and LGE- segments showed a decrease in contractility, indicating normalisation after a hypercontractile state or impairment of an initially normal contracting segment. No significant difference between LGE+ and LGE- segments was found for the change in segmental PLS. In the course of acute myocarditis with preserved ejection fraction, regional myocardial function adapts inversely in segments with and without LGE. As these effects seem to counterbalance each other, global functional parameters might be of limited use in monitoring functional recovery of these patients.

Dapagliflozin alleviates left ventricular hypertrophy and cardiac dysfunction in mice

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Ludwig Boltzmann Institute for Cardiovascular Research

Introduction

Sodium glucose cotransporter 2 inhibitors (SGLT2i) are a class of oral antidiabetic drugs. Recent clinical trials demonstrated and proved the cardiovascular benefit of SGLT2i in patients suffering from ischemic heart disease. In addition, left ventricular hypertrophy (LVH) is associated with cardiovascular events and using SGLT2i alleviated LVH in diabetic patients. However, only few studies investigated the effect of SGLT2i on regression of LVH in absence of diabetes.

Aim of the study

This study aimed to investigate whether the SGLT2i Dapagliflozin (DAPA) could attenuate LVH and cardiac dysfunction in a mouse model of pressure overload-induced LVH.

Methods

Male C57BL/6J mice (body weight 20-25g) were used. LVH was induced surgically by transverse aortic constriction (TAC). DAPA (1 mg/kg bodyweight/day) was administered through drinking water. The animals were divided in four groups: Group 1 underwent TAC for eight weeks (n=8). Group 2 concomitantly received DAPA for eight weeks after TAC (n=5). Group 3 received DAPA for only two weeks (in week 7 and 8 after TAC, n=5) to clarify if DAPA treatment could alleviate LVH at a later timepoint. Group 4 served as a sham control group (no LVH, n=8). Cardiac function was assessed using transthoracic echocardiography and invasive LV hemodynamic measurements.

Results

TAC resulted in a significant reduction in LV ejection fraction (LVEF) and significant increase in heart weight to body weight ratio (HW/BW) compared to sham (p&lt;0.001). In addition, TAC mice showed a significant increase of LV systolic pressure and end-diastolic pressure compared to sham (p&lt;0.01). Both the LVEF and LV functional parameters were markedly improved in mice treated with DAPA for eight weeks (p&lt;0.05). LV mass decreased compared to the untreated group. More importantly, DAPA treatment for only two weeks also improved LVEF and alleviated LVH compared to untreated TAC mice (p&lt;0.05). Furthermore, we also found that mice with only two weeks of DAPA treatment showed a tendency to improve LV hemodynamics.

Conclusions

DAPA was cardioprotective in a mouse model of pressure overload-induced LVH in absence of diabetes. It improved LV contractile function and LVH. DAPA also alleviated LVH and induced LV regression. Our findings uncovered that the SGLT2i DAPA contributed to the regression of LVH and cardiac fibrosis. Thus, administration of SLGT2i may be a novel adjunct therapy to boost reverse remodeling e.g. in patients with elective cardiac surgery and hypertrophic cardiomyopathy.

St Thomas Hospital polarizing cold cardioplegia does not have superior effects on hemodynamic parameters in an infarcted rat model

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Orphan Drugs

Background

The use of cardioplegic solutions is indispensable during cardiac arrest in order to reduce myocardial metabolism and oxygen demand. Most commonly, hypothermic hyperkalemic cardioplegic solutions are used for open heart surgery. However, high potassium concentrations have several effects that limit left ventricular recovery, such as intracellular calcium overload resulting in the loss of contractility and increased cell death. Recently, we have shown that polarized cardiac arrest results in similar myocardial protection and improves cardiac functional recovery in a porcine model of cardiopulmonary bypass.

Purpose

The purpose of this study was to identify and compare the hemodynamic effects of cold St Thomas’ Hospital polarizing cardioplegia (STH-Pol) in contrast to standard St Thomas’ Hospital cardioplegia (STH2) in rats with chronic myocardial infarction. We hypothesize that St Thomas’ Hospital polarizing cardioplegia shows superior protection on left ventricular hemodynamic recovery as compared to standard STH2 cardioplegia.

Methods

Permanent myocardial infarction was induced by permanent occlusion of the left anterior descending artery LAD on Sprague-Dawley rats (593 ± 65g, day of sacrifice). Six weeks post-MI, after echocardiography assessment, the animals were sacrificed, and hemodynamic parameters were measured in an erythrocyte-perfused isolated heart model (STH2, control group: n=5 or STH-Pol, study group: n=4). Fifteen minutes of Langendorff mode and 30 minutes of Working-heart mode were followed by cardiac arrest with the two types cardioplegia (was applied three times every 20 minutes (t1= 0, t2= 20, t3= 40)). STH-Pol, consisting of esmolol, adenosine and magnesium, was mixed with erythrocyte-buffer shortly prior to administration (1:4). After ischemia, the hearts were started with a hot shot with warm erythrocyte-buffer. Hemodynamic parameters were measured every five minutes in Langendorff mode and Working-heart mode. Finally, pump function was examined and tissue samples were taken for analysis of troponin-T and high-energy phosphates. Results will be given as % of preischemic baseline value.

Results

The use of STH-Pol instead of STH2 did not yield any significant differences in hemodynamic recovery (%) across the parameters of left atrial flow (LAF: 40.87 ± 13.22 vs. 53.24 ± 11.27), coronary flow (CF: 58 ± 14.36 vs. 76.21 ± 9) and cardiac output (CO: 42.82 ± 13.36 vs. 51.83 ± 11.76). Furthermore, we have not been able to identify superior effects of STH-Pol on stroke volume (SV: 46.55 ± 13.91 vs. 52.66 ± 11.33) recovery. Moreover, heart rate was comparable in both groups (92.07 ± 2.02 vs. 99.35 ± 1.72), which indicates swift reversal of negative chronotropic effects of esmolol.

Conclusion

Polarizing cardioplegic arrest does not show superior effects on hemodynamic parameters of left ventricular recovery after ischemia in chronically infarcted rat hearts as compared to depolarizing cardioplegic arrest.

Stromal Vascular Fraction-based patches generated under perfusion culture enhance cardiac function in rats with chronic myocardial infarction

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss National Foundation

The development of novel adjuvant angiogenic therapies to restore the low-perfused microvascular network upon myocardial infarction (MI) is crucial to avoid a possible end-stage heart failure. Of the current adult cell-based therapies, human adipose tissue-derived stromal vascular fraction cell (SVF) has vast reparative potential, principally due to: 1) its heterogeneous composition rich in mesenchymal stem cells (MSC), endothelial cells (EC), pericytes and hematopoietic cells, among others. In vitro engineering of SVF-based patches under unidirectional flow, applied by the help of a perfusion-based bioreactor, was found to increase certain cellular SVF subgroups such as pericytes, compared to static culture. In this study, we aimed at studying the potential of SVF-based engineered tissues in a model of chronic MI in nude rats. Human SVF cells were isolated upon liposuction and cultured on 3D collagen sponges (8 mm diameter, 3 mm thickness) either under constant unidirectional perfusion or in static condition for 5 days. Patches were characterized in terms of cellular composition prior to implantation. MI was induced by permanent ligation of the left anterior descending (LAD) coronary artery in male nude rats. Cardiac MRI was performed 4 weeks after MI; prior to the suture of patches and before sacrifice (4 weeks after implantation). Left ventricular ejection fraction (EF) was the surrogate marker and primary end point for cardiac pump function. Controls included untreated MI animals. Following perfusion culture, SVF cells were composed with a statistically superior percentage of pericytes, identified as CD45- CD34- CD146+ compared to static culture (28.06±10.03 and 3.37±2.50, respectively, p&lt;0.0007). The presence of other cell subpopulations was similar in the patches generated in perfusion or static culture. While the percentage of EF at the time of sacrifice resulted to be not statistically different between static and perfusion-based patches, statically generated constructs showed a general trend of decrease in the % EF before and after treatment (rat 1: 61.96 vs 52.90; rat 2: 55.39 vs 53.00; rat 3: 52.34 vs 50.62, respectively). Perfusion-cultured patches, instead, rather improved the cardiac function, measured as % EF (rat 1: 51.82 vs 58.72; rat 2: 51.66 vs 60.45; rat 3: 53.50 vs 52. 36, respectively for 4 weeks following MI and 4 weeks following treatment). When comparing the ratio of the % EF 8 weeks and 4 weeks between static or perfusion-based patches and the untreated controls, rats treated with patches generated under perfusion resulted to show higher levels of % EF, with an almost statistically difference (p=0.0556), compared to the control group. The observed results showed the great potential of human SVF-based patches in the improvement of the heart pump function.

Hypersensibilité au vaccin anti-COVID ? analyses de 1000 avis allergologiques

Introduction (contexte de la recherche)

Les services d’allergologie ont été fortement sollicités en raison de l’appréhension vis-à-vis du risque allergique des vaccins contre la COVID-19.

Objectif

Nous rapportons les 1000 premières prises en charge proposées et le résultat des investigations allergologiques réalisées.

Méthodes

Nous avons mis en place un système d’avis-COVID par mail à l’aide d’un questionnaire. Ceci nous a permis de colliger, de façon rétrospective les données démographiques des patients, les conduites à tenir proposées, en fonction des données cliniques fournies et des recommandations de la SFA. Pour certains, des tests cutanés ont été nécessaires : prick-test aux PEGs 3500/1500 et polysorbate 80 avec des concentrations maximales respectives de 100 mg/mL et 1000 mg/mL. Lorsque des fonds de flacon de vaccin étaient disponibles, nous avons réalisé : prick-test et IDR jusqu’à leur concentration pure. Certaines vaccinations jugées à risque ont été réalisées dans le service.

Résultats

Du 20 janvier au 24 novembre 2021, 1000 avis allergologiques ont été donnés par mail en dehors des heures de consultation. Il s’agissait de 773 avis pré-vaccinaux et 227 post-vaccinaux. L’âge moyen des patients était de 55 ans, avec une majorité de femmes. Nous avons levé la contre-indication allergologique à la vaccination dans 99,4 % des cas. Elle a été recommandée en centre de vaccination conventionnel pour 44 % sans précaution particulière, 31 % sous antihistaminique, 30 % avec 30 minutes de surveillance. 31 patients ont été vaccinés dans notre service sans réaction. L’indication de tests cutanés a été retenue dans 6,9 % des cas. Nous avons mis en évidence une sensibilisation aux excipients et aux vaccins chez 4 patients du groupe pré-vaccinal et chez une patiente du groupe post-vaccinal qui a bénéficié d’une désensibilisation avec succès.

Conclusions

La gestion par mail des avis-COVID a permis de limiter les consultations dédiées en présentiel et de maintenir l’intégralité des activités du service. Nous avons proposé une réponse rapide avec traçabilité écrite, souvent exigée. Seuls 4 patients restent à ce jour contre-indiqués à la vaccination en raison d’une allergie aux PEGs.

Investigating Differences in Behavior and Brain in Human-Human and Human-Autonomous Vehicle Interactions in Time-Critical Situations

Some studies provide evidence that humans could actively exploit the alleged technological advantages of autonomous vehicles (AVs). This implies that humans may tend to interact differently with AVs as compared to human driven vehicles (HVs) with the knowledge that AVs are programmed to be risk-averse. Hence, it is important to investigate how humans interact with AVs in complex traffic situations. Here, we investigated whether participants would value interactions with AVs differently compared to HVs, and if these differences can be characterized on the behavioral and brain-level. We presented participants with a cover story while recording whole-head brain activity using fNIRS that they were driving under time pressure through urban traffic in the presence of other HVs and AVs. Moreover, the AVs were programmed defensively to avoid collisions and had faster braking reaction times than HVs. Participants would receive a monetary reward if they managed to finish the driving block within a given time-limit without risky driving maneuvers. During the drive, participants were repeatedly confronted with left-lane turning situations at unsignalized intersections. They had to stop and find a gap to turn in front of an oncoming stream of vehicles consisting of HVs and AVs. While the behavioral results did not show any significant difference between the safety margin used during the turning maneuvers with respect to AVs or HVs, participants tended to be more certain in their decision-making process while turning in front of AVs as reflected by the smaller variance in the gap size acceptance as compared to HVs. Importantly, using a multivariate logistic regression approach, we were able to predict whether the participants decided to turn in front of HVs or AVs from whole-head fNIRS in the decision-making phase for every participant (mean accuracy = 67.2%, SD = 5%). Channel-wise univariate fNIRS analysis revealed increased brain activation differences for turning in front of AVs compared to HVs in brain areas that represent the valuation of actions taken during decision-making. The insights provided here may be useful for the development of control systems to assess interactions in future mixed traffic environments involving AVs and HVs.

Global health from home - results from a German student-led online lecture series during COVID-19

Background

The COVID-19 pandemic calls for a skilled health workforce, yet global health is largely missing in the medical curriculum in Germany. The interdisciplinary national student “Global Health Network” therefore initiated an online lecture series. “Global Health - perspectives, opportunities and challenges” included 14 lectures on a range of topics held by German and international academics from October 2020 to January 2021.

Methods

Evaluations were performed prior to, at midterm and after the series, including 5-point likert scales and open questions. Using quantitative and qualitative approaches, participants' motivation and learning outcomes of global health education were analysed.

Results

A total of 1393 students registered for the series. Individual lectures attracted on average 400 participants, mainly female medical students between 20-25 years, but also a variety of ages, genders and disciplines. Main reasons for participation included interest in COVID-19-related developments, learning about global health-specific topics, and professional development. More than 40% of participants reported to know little about global health before attending; after the lecture series, only 10% made this statement. In addition, 90% of participants perceived an increase of motivation to learn more about the topics, while about 40% gained motivation to become practically involved in the field. The lecture series was accredited in the curriculum at some universities, thus innovating the curriculum and enabling formal credits.

Conclusions

The new model of student-led online teaching proved to be feasible and demonstrated students' interest and positive impact on global health knowledge. Further institutional change and inclusion of global health in the curricula have to follow.

Key messages

Students need global health education to respond to global health-related challenges. Volunteer student-led initiatives can increase knowledge and interest and be an important driver for change towards improving global health education.

Localization of ST-elevation on ECG is associated with regional myocardial fibrosis in acute myocarditis

Funding Acknowledgements

Type of funding sources: None.

Introduction

Both ST elevation (STE) on ECG and late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMR) are related to poor outcome in myocarditis.

Purpose

We evaluated if there is an association between regional STE and LGE pattern in patients with suspected myocarditis.

Methods

51 patients (42 male, 32 ± 13 years old) underwent 12-lead ECG and CMR with LGE due to suspected myocarditis. &gt;1mm STE was assessed in the antero-septal (V1-V4, aVR), inferior (II, III, aVF) and lateral (I, aVL, V5-V6) localizations. LGE was quantified as visual presence score (VPS) (1-17) and visual transmurality score (VTS) (1-68) on CMR, according to the 17-segment AHA model. STE and LGE were correlated using linear regression analysis. 

Results

31% of the patients had STE on admission ECG and a median VPS of 3 (IQR: 1-5) and VTS of 6 (IQR: 3-11) on CMR. STE showed an association with VPS and VTS in univariate and multivariate analysis (p &lt; 0.001 all). STE was most frequent in the lateral and inferior leads (48% and 31%) which correlated with regional VPS and VTS in univariate model (p &lt; 0.05 all), and remained significant in multivariate analysis for VPS (p &lt; 0.05 both). STE was less frequent in the antero-septal region (21%, where no association between LGE and STE could be revealed (p &gt; 0.05 all).

Conclusions

 Inferior and lateral STE in myocarditis is associated with regional LGE on CMR, which is an indicator of myocardial fibrosis and possible poor outcome. Our results need not be validated on larger cohorts with follow-up.

Myocardial fibrosis quantification methods by cardiovascular magnetic resonance imaging with contrast-enhancement in patients with Fabry disease

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): National Agency for Academic Exchange (NAWA).

Background. Presence and extent of late gadolinium enhancement (LGE) in patients with Fabry disease (FD) is a predictor of adverse cardiac events. However there is no gold standard method to quantify the amount of myocardial fibrosis in cardiac magnetic resonance imaging (CMR).

Purpose. The aim of this study was to establish the most reliable and reproducible technique for quantifying LGE in patients with FD.

Methods. 68 patients with FD (40% male, 40 ± 16 years old) treated in our outpatient clinic, who underwent CMR with administration of 0.2 mmol of gadobutrol per kilogram of body weight between December 2012 and March 2019 were enrolled into the study. Presence of LGE was described in 25 patients (37%). Twenty patients underwent CMR with the same LGE sequence (Philips 1.5 Tesla, two-dimensional multi-breath-hold inversion recovery sequence) and were enrolled into further analysis. LGE quantifications were performed using gray-scale thresholds with 2, 3, 4, 5 and 6 standard deviations (SD) above the mean signal intensity for the remote myocardial tissue, full width at half maximum method (FWHM), visual assessment with threshold (VAT) and fully manual method (MM; Philips IntelliSpace Portal 10). LGE quantifications were done twice by the same observer in different time periods and once by another observer. Intraclass correlation coefficient (ICC), Bland- Altman analysis and coefficient of variation (CV) were used to assess intra- and interobserver reliability and reproducibility.

Results. The mean quantity of fibrosis mass  (in gram) in all studied patients was: 35.5 ± 18.7 at 2SD, 21.0 ± 12.8 at 3SD, 12.7 ± 8.5 at 4SD, 8.0 ± 5.7 at 5SD, 5.3 ± 4.1 at 6SD, 1.9 ± 1.8 at FWHM, 8.6 ± 7.4 at VAT and 9.1 ± 6.1 at MM. Intra-observer reliability of almost all studied LGE quantification methods was excellent, with a range of ICCs from 0.90 for 6SD to 0.95 for VAT, with one exception for FWHM, which had good intraobserver reliability (ICC 0.84; all P &lt; 0.05). Interobserver reliability was excellent for VAT (ICC 0.94) and good for all other LGE quantifications methods (range of ICCs from 0.76 for MM to 0.87 for 5SD, all P &lt; 0.05). 5SD had the lowest CV (6%) for intraobserver reproducibility and 2SD and VAT for interobserver reproducibility (35% and 38%). FWHM had the highest CV for both intra- and interobserver reproducibility (63% and 94%, accordingly).

Conclusions

1. All studied methods of LGE quantification in patients with FD and presence of myocardial fibrosis have good to excellent intra- and interobserver reliability.

2. The total amount of LGE differs in studied LGE quantifications methods. Therefore in clinical practice it is important to report which technique of LGE quantification was used and choose the same for CMR-follow up.

3. FWHM might be avoided for LGE quantification in patients with FD due to the highest intra- and interobserver variability in comparison to other available techniques.

A quantum magnetic analogue to the critical point of water

At the liquid-gas phase transition in water, the density has a discontinuity at atmospheric pressure; however, the line of these first-order transitions defined by increasing the applied pressure terminates at the critical point¹, a concept ubiquitous in statistical thermodynamics². In correlated quantum materials, it was predicted³ and then confirmed experimentally^4,5 that a critical point terminates the line of Mott metal-insulator transitions, which are also first-order with a discontinuous charge carrier density. In quantum spin systems, continuous quantum phase transitions⁶ have been controlled by pressure^7,8, applied magnetic field^9,10 and disorder¹¹, but discontinuous quantum phase transitions have received less attention. The geometrically frustrated quantum antiferromagnet SrCu₂(BO₃)₂ constitutes a near-exact realization of the paradigmatic Shastry-Sutherland model^12-14 and displays exotic phenomena including magnetization plateaus¹⁵, low-lying bound-state excitations¹⁶, anomalous thermodynamics¹⁷ and discontinuous quantum phase transitions^18,19. Here we control both the pressure and the magnetic field applied to SrCu₂(BO₃)₂ to provide evidence of critical-point physics in a pure spin system. We use high-precision specific-heat measurements to demonstrate that, as in water, the pressure-temperature phase diagram has a first-order transition line that separates phases with different local magnetic energy densities, and that terminates at an Ising critical point. We provide a quantitative explanation of our data using recently developed finite-temperature tensor-network methods^17,20-22. These results further our understanding of first-order quantum phase transitions in quantum magnetism, with potential applications in materials where anisotropic spin interactions produce the topological properties^23,24 that are useful for spintronic applications.

Menoci: lightweight extensible web portal enhancing data management for biomedical research projects

BACKGROUND

Biomedical research projects deal with data management requirements from multiple sources like funding agencies' guidelines, publisher policies, discipline best practices, and their own users' needs. We describe functional and quality requirements based on many years of experience implementing data management for the CRC 1002 and CRC 1190. A fully equipped data management software should improve documentation of experiments and materials, enable data storage and sharing according to the FAIR Guiding Principles while maximizing usability, information security, as well as software sustainability and reusability.

RESULTS

We introduce the modular web portal software menoci for data collection, experiment documentation, data publication, sharing, and preservation in biomedical research projects. Menoci modules are based on the Drupal content management system which enables lightweight deployment and setup, and creates the possibility to combine research data management with a customisable project home page or collaboration platform.

CONCLUSIONS

Management of research data and digital research artefacts is transforming from individual researcher or groups best practices towards project- or organisation-wide service infrastructures. To enable and support this structural transformation process, a vital ecosystem of open source software tools is needed. Menoci is a contribution to this ecosystem of research data management tools that is specifically designed to support biomedical research projects.

A Nordic-Baltic perspective on indications for proton therapy with strategies for identification of proper patients

The beneficial effects of protons are primarily based on reduction of low to intermediate radiation dose bath to normal tissue surrounding the radiotherapy target volume. Despite promise for reduced long-term toxicity, the percentage of cancer patients treated with proton therapy remains low. This is probably caused by technical improvements in planning and delivery of photon therapy, and by high cost, low availability and lack of high-level evidence on proton therapy. A number of proton treatment facilities are under construction or have recently opened; there are now two operational Scandinavian proton centres and two more are under construction, thereby eliminating the availability hurdle. Even with the advantageous physical properties of protons, there is still substantial ambiguity and no established criteria related to which patients should receive proton therapy. This topic was discussed in a session at the Nordic Collaborative Workshop on Particle Therapy, held in Uppsala 14-15 November 2019. This paper resumes the Nordic-Baltic perspective on proton therapy indications and discusses strategies to identify patients for proton therapy. As for indications, neoplastic entities, target volume localisation, size, internal motion, age, second cancer predisposition, dose escalation and treatment plan comparison based on the as low as reasonably achievable (ALARA) principle or normal tissue complication probability (NTCP) models were discussed. Importantly, the patient selection process should be integrated into the radiotherapy community and emphasis on collaboration across medical specialties, involvement of key decision makers and knowledge dissemination in general are important factors. An active Nordic-Baltic proton therapy organisation would also serve this purpose.

Mitral annular calcification in the elderly - Quantitative assessment

PURPOSE

To determine the reliability of subjective and objective quantification of mitral annular calcification (MAC) in elderly patients with severe aortic stenosis, to define quantitative sex- and age-related reference values of MAC, and to correlate quantitative MAC with mitral valve disease.

METHODS

In this retrospective, IRB-approved study, we included 559 patients (268 females, median age 81 years, inter-quartile range 77-85 years) with severe aortic stenosis undergoing CT. Four independent readers performed subjective MAC categorization as follows: no, mild, moderate, and severe MAC. Two independent readers performed quantitative evaluation of MAC using the Agatston score method (Agatston_MAC). Mitral valve disease was determined by echocardiography.

RESULTS

Subjective MAC categorization showed high inter-reader agreement for no (k ​= ​0.88) and severe MAC (k ​= ​0.75), whereas agreement for moderate (k ​= ​0.59) and mild (k ​= ​0.45) MAC was moderate. Intra-reader agreement for subjective MAC categorization was substantial (k ​= ​0.69 and 0.62). Inter- and intra-reader agreement for Agatston_MAC were excellent (ICC ​= ​0.998 and 0.999, respectively), with minor inconsistencies in MAC involving the left ventricular outflow tract/aortic valve. There were significantly more women than men with MAC (n ​= ​227, 85% versus n ​= ​209, 72%; p ​< ​0.001), with a significantly higher Agatston_MAC (median 597, range 81-2055 versus median 244; range 0-1565; p ​< ​0.001), particularly in patients ≥85 years of age. Agatston_MAC showed an area-under-the-curve of 0.84 to diagnose mitral stenosis, whereas there was no association of Agatston_MAC with mitral regurgitation (p ​> ​0.05).

CONCLUSIONS

Our study in elderly patients with severe aortic stenosis shows that quantitative MAC scoring is more reliable than subjective MAC assessment. Women show higher Agatston_MAC scores than men, particularly in the elderly population. Agatston_MAC shows high accuracy to diagnose mitral stenosis.

Efficacy of antiseptics in a novel 3-dimensional human plasma biofilm model (hpBIOM)

The increasing incidence of non-healing wounds constitutes a pivotal socio-economic burden. 60-80% of chronic wounds are colonized by pathogenic microorganisms within a protective extracellular polymeric substance, bearing a great challenge in wound management. Human plasma was used to prepare the biofilm model (hpBIOM), adding pathogens to the plasma and forming Coagula-like discs with integrated pathogens were produced. The antiseptics Octenisept and Lavasorb were tested regarding their antibacterial properties on clinically relevant biofilm-growing bacteria (MRSA, P. aeruginosa) in the hpBIOM. Biofilm-typical glycocalyx-formation was confirmed using immunohistochemical staining. Treatment of a 12 h-maturated biofilm with Octenisept resulted in complete eradication of P. aeruginosa and MRSA after 48 h. Lavasorb proved less effective than Octenisept in this setting. In more mature biofilms (24 h), both antiseptics showed a delayed, partially decreased efficacy. Summarized, the hpBIOM provides essential factors for a translational research approach to be used for detailed human biofilm analyses and evaluation of antimicrobial/-biofilm properties of established and novel therapeutic strategies and products. Octenisept and Lavasorb showed an attenuated efficacy in the hpBIOM compared to planktonic conditions and previously published biofilm-studies, prompting the question for the necessity of introducing new international standards and pre-admission requirements on a translational base.

Autoimmunhämolytische Anämie als seltene Nebenwirkung einer Therapie mit Pembrolizumab bei metastasiertem Melanom

Checkpoint-Inhibitoren wie Pembrolizumab, Nivolumab und Ipilimumab stellen unverzichtbare Wirkstoffe zur Behandlung fortgeschrittener oder metastasierter Melanome dar. Durch eine Aktivierung zytotoxischer T-Zellen durch diese Substanzen kommt es neben einer antitumoralen Immunantwort bei vielen Patienten auch zu einer Vielzahl an immunvermittelten Nebenwirkungen, die jedes Organ des Körpers betreffen können. Neben häufigen autoimmun vermittelten Nebenwirkungen, wie z. B. einer Kolitis, einer Pneumonitis, einer Thyreoiditis und einer Hypophysitis, die in der Regel rasch erkannt werden, können auch seltene Nebenwirkungen auftreten, die initial oft nicht direkt als Nebenwirkung der Therapie interpretiert werden.

Bei einer 66 Jahre alten Patientin wurde ein Melanom am linken Unterschenkel exzidiert (Typ NMM, Tumordicke 3 mm; BRAF, NRAS und c-Kit jeweils Wildtyp), Sentinelnodebiopsie inguinal positiv, darauffolgende Lymphknotendissektion ohne Metastasennachweis. Sechs Monate später traten inguinale Lymphknotenfiliae sowie mehrere kutane Metastasen am linken Bein auf. Es erfolgte eine knappe Resektion in toto mit anschließender adjuvanter Radiatio (inguinal und Knie links, GRD 45 Gy). Bereits einige Wochen später zeigten sich am linken Bein erneut mehrere kutane Filiae sowie Lymphknotenfiliae inguinal und iliakal links. Aufgrund des mittlerweile ausgebildeten massiven Lymphödems wurde bei nicht-operabler, lokoregionärer Metastasierung 2016 eine Therapie mit Pembrolizumab begonnen.

Nach der 12. Gabe bildete sich eine normochrome, normozytäre Anämie mit transfusionsbedürftigem Hämoglobin (Hb)-Abfall bis auf 8,4 mg/dl aus. Gastro- und koloskopisch konnte keine Blutungsquelle nachgewiesen werden, mittels Knochenmarksbiopsie wurden eine Infiltration des Knochenmarks durch Melanomzellen sowie eine Pure Red Cell Aplasia ausgeschlossen. Bei erhöhter LDH, erniedrigten Werten für Haptoglobin und Retikulozyten sowie positivem direkten Coombs-Test für c3d wurde die Diagnose einer autoimmunhämolytischen Anämie (AIHA) mit Beteiligung aller Vorstufen der roten Reihe gestellt und eine Therapie mit Methylprednisolon begonnen. Bei jedem Versuch die Therapie mit Pembrolizumab nach Stabilisierung des Hb-Wertes fortzuführen, zeigte sich ein erneuter transfusionsbedürftiger Abfall auf Hb-Werte von bis zu 6 mg/dl. Wir entschieden uns die Therapie mit Pembrolizumab nach 15 Zyklen bei kompletter Remission der Metastasen zu beenden; seitdem zeigen sich in Laborkontrollen normwertige Hb-Werte. Da sich nach einigen Monaten erneut ein Progress ausbildete, wurde bei negativem BRAF-Mutationsstatus eine Therapie mit Nivolumab begonnen, hierunter kam es nicht zur erneuten Ausbildung einer AIHA.

Die Entwicklung einer Anämie ist eine seltene Nebenwirkung einer Therapie mit Checkpoint-Inhibitoren. Als weitere Ursache wurde neben der hier gezeigten AIHA auch die aplastische Anämie als immunvermittelte Nebenwirkung beschrieben.

In den wenigen bisher publizierten Fällen bildete sich die Anämie i. R. der Therapie mit Checkpoint-Inhibitoren frühzeitig aus und zeigte oft ein zögerliches Ansprechen auf Steroide. Bisher sind nur wenige Fälle beschrieben, bei denen eine Re-Exposition ohne erneutes Aufflammen der Anämie möglich war. Trotz immunsuppressiver Therapie sind letale Verläufe beschrieben. Dies verdeutlicht die Notwendigkeit regelmäßiger Laboruntersuchungen unter und nach der Therapie mit Checkpoint-Inhibitoren. In unserem Fall kam es erfreulicherweise nach erneuter Gabe eines Checkpoint-Inhibitors nicht zum erneuten Auftreten der AIHA. Ob dies dem Wechsel von Pembrolizumab zu Nivolumab geschuldet ist, muss derzeit leider unbeantwortet bleiben.

[Auditory group therapy in adult cochlear implant rehabilitation]

BACKGROUND

Auditory training is an established intervention in adult cochlear implant (CI) aural rehabilitation. In most cases, training is implemented in an individual therapy setting. Increasing patient numbers and the associated time-economic and cost-related demands as well as psychosocial and communicative aspects support the use of aural group interventions.

OBJECTIVES

This study aimed 1) to describe concepts and contents of group interventions for adult CI users and 2) to present results of a questionnaire-based evaluation.

METHODS

Group interventions have been offered at the CI Centre Erlangen CICERO for several years. In Auditory Training Groups, exercises have priority, while Thematic Group Workshops focus on psychosocial aspects and provide information for the participants. The Auditory Training Groups were evaluated based on a patient questionnaire. Additionally, the reliability of the questionnaire was analyzed.

RESULTS

The median overall satisfaction of CI users participating in Auditory Training Groups was rated as good. Training of speech perception in noise as well as communicative exchange are of great importance for CI users. They rated the therapeutic design as very good to good. Reliability analysis showed significant positive intercorrelations of the questionnaire items.

CONCLUSION

Group interventions are well accepted by CI users and represent a useful complement to individual therapy during the rehabilitation process. As group interventions place special demands on patients and therapists, structured and well-proven concepts should be used in practice.

Impact of probiotics on pathogen survival in an innovative human plasma biofilm model (hpBIOM)

BACKGROUND

Despite of medical advances, the number of patients suffering on non-healing chronic wounds is still increasing. This fact is attended by physical and emotional distress and an economic load. The majority of chronic wounds are infected of harmful microbials in a protecting extracellular matrix. These biofilms inhibit wound healing. Biofilm-growing bacteria developed unique survival properties, which still challenge the appropriate wound therapy. The present in-vitro biofilm models are not suitable for translational research. By means of a novel in-vivo like human plasma biofilm model (hpBIOM), this study systematically analysed the influence of 3 probiotics on the survival of five clinically relevant pathogenic microorganisms.

METHODS

Human plasma was used to produce the innovate biofilm. Pathogenic microorganisms were administered to the plasma. By stimulating the production of a fibrin scaffold, stable coagula-like discs with integrated pathogens were produced. The five clinically relevant pathogens P. aeruginosa, S. aureus, S. epidermidis, E. faecium and C. albicans were challenged to the probiotics L. plantarum, B. lactis and S. cerevisiae. The probiotics were administered on top of the biofilm and the survival was quantified after 4 h and 24 h of incubation. For statistics, two-way ANOVA with post-hoc Tukey's HSD test was applied. P-value > 0.05 was considered to be significant.

RESULTS

SEM micrographs depicted the pathogens on the surface of the fibrin scaffold, arranged in close proximity and produced the glycocalyx. The application of probiotics induced different growth-reducing capacities towards the pathogens. B. lactis and S. cerevisiae showed slight bacteria-reducing properties. The survival of C. albicans was not affected at all. The most antimicrobial activity was detected after the treatment with L. plantarum.

CONCLUSIONS

This study successfully reproduced a novel human biofilm model, which provides a human wound milieu and individual immune competence. The success of bacteriotherapy is dependent on the strain combination, the number of probiotics and the activity of the immune cells. The eradicating effect of L. plantarum on P. aeruginosa should be emphasized.

Bacterial viability in oral biofilm after tooth brushing with amine fluoride or sodium fluoride

OBJECTIVE

The aim of this study was to investigate the effects of sodium fluoride (NaF) and amine fluoride (AmF) on bacterial viability in the oral cavity.

MATERIAL AND METHODS

Healthy subjects brushed their teeth with either fluoride free toothpaste, NaF- or AmF-containing toothpaste. Biofilm smears from different locations were collected before and immediately and 30 and 120 min after tooth brushing. The smears were stained with live/dead bacterial staining, and the number of the respective bacteria was counted. The data were statistically analyzed by comparing the numbers of bacteria before and after the application of no fluoride, NaF and AmF.

RESULTS

The highest numbers of bacteria were found in the tongue biofilm, followed by the palatal and cheek biofilm. The lowest numbers were found in the mouth floor biofilm. After the application of AmF, no changes in the numbers of bacteria were found in the biofilms, except for the cheek, where they were reduced. After the application of NaF, the number of bacteria decreased significantly in all biofilms. After 120 min, bacterial regrowth was complete.

CONCLUSIONS

AmF has only little effect on the bacterial viability of oral biofilms. NaF application reduces the number of living bacteria in the oral biofilms. This effect lasts not longer than 120 min.

Effective dose in low-dose CT compared with radiography for templating of total hip arthroplasty

Background Recently, total hip arthroplasty (THA) has come to focus on restoration of individual anatomy including femoral neck anteversion and global offset (femoral and acetabular offset). Three-dimensional (3D) computed tomography (CT) data could provide a better basis for preoperative templating. The use of CT has been hampered by high radiation dose. Purpose To evaluate the effective dose used in pelvis and hip CT for THA templating. Material and Methods CT data from two clinical trials of THA were evaluated for CT scan length and volume CT dose index (CTDI_vol). The effective doses from hip-knee-ankle CT and pelvis and hip radiography were compared. Conversion factors for effective dose for radiography were calculated using the PCXMC software. Results A reduced dose CT protocol for pelvis imaging gave a substantial dose reduction compared with standard CT, while maintaining sufficient image quality. Between the two clinical trials there was a significant reduction in effective CT dose corresponding to changes in the CT protocol ( P < 0.01). The CT dose for the latter group was similar to, but nevertheless significantly higher than for, radiography ( P < 0.01). However, in the latter group the theoretical minimum dose for CT, using the minimum scan length required by the templating software, was equal to the dose from radiography. Conclusion Although the CT dose remained higher than for radiography, potential reductions in scan length could reduce the dose further so that CT would have a comparable level of risk to radiography with the added benefit of 3D templating.

Registration of phase-contrast images in propagation-based X-ray phase tomography

X-ray phase tomography aims at reconstructing the 3D electron density distribution of an object. It offers enhanced sensitivity compared to attenuation-based X-ray absorption tomography. In propagation-based methods, phase contrast is achieved by letting the beam propagate after interaction with the object. The phase shift is then retrieved at each projection angle, and subsequently used in tomographic reconstruction to obtain the refractive index decrement distribution, which is proportional to the electron density. Accurate phase retrieval is achieved by combining images at different propagation distances. For reconstructions of good quality, the phase-contrast images recorded at different distances need to be accurately aligned. In this work, we characterise the artefacts related to misalignment of the phase-contrast images, and investigate the use of different registration algorithms for aligning in-line phase-contrast images. The characterisation of artefacts is done by a simulation study and comparison with experimental data. Loss in resolution due to vibrations is found to be comparable to attenuation-based computed tomography. Further, it is shown that registration of phase-contrast images is nontrivial due to the difference in contrast between the different images, and the often periodical artefacts present in the phase-contrast images if multilayer X-ray optics are used. To address this, we compared two registration algorithms for aligning phase-contrast images acquired by magnified X-ray nanotomography: one based on cross-correlation and one based on mutual information. We found that the mutual information-based registration algorithm was more robust than a correlation-based method.

Medium-chain fatty acids modulate myocardial function via a cardiac odorant receptor

Several studies have demonstrated the expression of odorant receptors (OR) in various human tissues and their involvement in different physiological and pathophysiological processes. However, the functional role of ORs in the human heart is still unclear. Here, we firstly report the functional characterization of an OR in the human heart. Initial next-generation sequencing analysis revealed the OR expression pattern in the adult and fetal human heart and identified the fatty acid-sensing OR51E1 as the most highly expressed OR in both cardiac development stages. An extensive characterization of the OR51E1 ligand profile by luciferase reporter gene activation assay identified 2-ethylhexanoic acid as a receptor antagonist and various structurally related fatty acids as novel OR51E1 ligands, some of which were detected at receptor-activating concentrations in plasma and epicardial adipose tissue. Functional investigation of the endogenous receptor was carried out by Ca²⁺ imaging of human stem cell-derived cardiomyocytes. Application of OR51E1 ligands induced negative chronotropic effects that depended on activation of the OR. OR51E1 activation also provoked a negative inotropic action in cardiac trabeculae and slice preparations of human explanted ventricles. These findings indicate that OR51E1 may play a role as metabolic regulator of cardiac function.

Effects of water-soluble fraction of petroleum on growth and prey consumption of juvenile Hoplias aff. malabaricus (Osteichthyes: Erythrinidae)

The influence of the water-soluble fraction of petroleum (WSF) on prey consumption and growth of juvenile trahira Hoplias aff. malabaricus was investigated. Juveniles were submitted to either WSF or Control treatment over 28 days, and jewel tetra Hyphessobrycon eques adults were offered daily as prey for each predator. Total prey consumption ranged from 16 to 86 individuals. Despite the initially lower prey consumption under WSF exposure, there were no significant differences in overall feeding rates between the two treatments. Water-soluble fraction of petroleum had a negative effect on the growth in length of H. aff. malabaricus juveniles. Although unaffected, prey consumption suggested a relative resistance in H. aff. malabaricus to WSF exposition and the lower growth of individuals exposed to WSF than the Control possibly reflects metabolic costs. The implications of the main findings for the individual and the food chain are discussed, including behavioral aspects and the role played by this predator in shallow aquatic systems.

Designing driver assistance systems with crossmodal signals: multisensory integration rules for saccadic reaction times apply

Modern driver assistance systems make increasing use of auditory and tactile signals in order to reduce the driver's visual information load. This entails potential crossmodal interaction effects that need to be taken into account in designing an optimal system. Here we show that saccadic reaction times to visual targets (cockpit or outside mirror), presented in a driving simulator environment and accompanied by auditory or tactile accessories, follow some well-known spatiotemporal rules of multisensory integration, usually found under confined laboratory conditions. Auditory nontargets speed up reaction time by about 80 ms. The effect tends to be maximal when the nontarget is presented 50 ms before the target and when target and nontarget are spatially coincident. The effect of a tactile nontarget (vibrating steering wheel) was less pronounced and not spatially specific. It is shown that the average reaction times are well-described by the stochastic "time window of integration" model for multisensory integration developed by the authors. This two-stage model postulates that crossmodal interaction occurs only if the peripheral processes from the different sensory modalities terminate within a fixed temporal interval, and that the amount of crossmodal interaction manifests itself in an increase or decrease of second stage processing time. A qualitative test is consistent with the model prediction that the probability of interaction, but not the amount of crossmodal interaction, depends on target-nontarget onset asynchrony. A quantitative model fit yields estimates of individual participants' parameters, including the size of the time window. Some consequences for the design of driver assistance systems are discussed.

Conversion factors for estimation of effective dose in paediatric chest tomosynthesis

For chest tomosynthesis in adults, a conversion factor of 0.26 mSv/Gy cm² has been reported for calculating the effective dose from the registered dose-area-product. The aim of this study was to determine conversion factors for chest tomosynthesis in children. Using the Monte Carlo-based computer software PCXMC 2.0, simulations were performed on modified phantoms for males and females aged 8-19 y, in the posteroanterior and anteroposterior projection, with energies 80-140 kV and copper filtration 0.1-0.3 mm. Resulting conversion factors ranged between 0.23 and 1.09 mSv/Gy cm², decreased with patient age, were significantly higher in the anteroposterior projection and increased with increased energy or copper filtration. To avoid an underestimation of effective dose in children, it is recommended to use age-dependent conversion factors. As a simplified approach, three conversion factors might be used for posteroanterior chest tomosynthesis and radiography in children, namely 0.6 (8-10 y), 0.4 (11-14 y) and 0.3 mSv/Gy cm² (15-19 y).