Pop-up Langmuir probe diagnostic in the water cooled divertor of Wendelstein 7-X

The design, development, and successful implementation of pop-up Langmuir probes installed in the water-cooled divertor of W7-X are described. The probes are controlled by drive coils (actuators) installed behind the divertor plates. These drive coils make use of the magnetic field in W7-X to move the probe tips into and out of the plasma. The drive coils were installed in the vacuum vessel after extensively testing the durability of the coils and analyzing the criteria for safe operation. The probe design is carefully tailored for each of the 36 probe tips in order to be suitable for the different magnetic field configurations used in W7-X and ensure that the probes do not present leading edges to the magnetic flux tubes. An electronic bridge circuit is used for measurement to compensate for the effects of signal propagation time on the long cable lengths used. The diagnostic is integrated with the segment control of W7-X for automated operation and control of the diagnostic. The evaluation of the results from the plasma operation is presented after accounting for appropriate sheath expansion for negative bias voltage on the probes.

[Posterolateral instability of the knee joint]

The posterolateral corner of the knee is composed of a multilayered complex of ligamentous, musculotendinous, and capsular structures, which interact in a synergistic stabilizing manner with the central structures, particularly the posterior cruciate ligament. Injuries of the posterolateral corner are generally accompanied by rupture of the posterior cruciate ligament. Depending on the injured structures, injuries of the posterolateral corner result in posterolateral rotational instability alone (Fanelli A) or with lateral instability (Fanelli B/C). For rotational instability alone, isolated popliteus bypass is an effective procedure; with concomitant lateral instability in flexion, additional stabilization of the lateral collateral ligament is required. Most of the various available techniques are described as open reconstruction procedures. In recent years, arthroscopic techniques for posterolateral reconstruction have also been successfully developed.

Influence of leg axis alignment on MRI T2* mapping of the knee in young professional soccer players

BACKGROUND

Investigation of the association between leg axis alignment and biochemical MRI in young professional soccer players in order to identify a potential influence of the leg axis on cartilage regions at risk.

METHODS

Sixteen professional soccer players (21 ± 3 years) underwent static and dynamic leg axis analysis via radiation free DIERS formetric 4 D as well as 3-T MRI examination of both knees. Quantitative T2* mapping of the knee cartilage was performed and T2* values were evaluated as 144 regions of interest. Subgroup analysis was performed in players with severe varus alignment (> 6°).

RESULTS

Analysis of the leg axis geometry revealed a mean static alignment of 6.6° ± 2.5 varus and a mean dynamic alignment of 5.1° ± 2.6 varus. Quantitative T2* mapping showed significantly increased T2* values in the superficial cartilage layer compared to the deeper region (p < 0.001) as well as a significant increase in relaxation times in the femoral cartilage from anterior to intermediate to posterior (p < 0.001). Combination of both methods revealed a significant correlation for the degree of varus alignment and the femoral, posterior, deep region of the medial knee compartment (r = 0.4; p = 0.03). If severe varus alignment was present this region showed a significant increase in relaxation time compared to players with a less pronounced leg axis deviation (p = 0.003).

CONCLUSION

This study demonstrates that varus alignment in young soccer players is associated with elevated T2* relaxation times in the deep cartilage layer of the medial, posterior, femoral compartment and might therefore be a contributing factor in the early pathogenesis of manifest cartilage lesions. Therefore, these findings should be considered in the development of preventive training programs.

Current standard of care for distal femur fractures in Germany and Switzerland

BACKGROUND

Distal femur fractures occur with an incidence of 4.5/100,000 and show a prevalence of 0.4%. Causes include low-impact trauma in older patients and high-impact trauma in younger patients without pre-existing medical conditions. The aim of this study was to perform a comprehensive evaluation of trauma mechanisms, trauma-promoting factors, comorbidities, medication history and type of surgical care to provide an overview of the causes of injury and the most appropriate therapeutic approach.

METHODS

In this multicenter cohort study a retrospective analysis of 229 patients who sustained a distal femur fracture between January 2011 and December 2020 was performed. Individual fracture patterns, fracture predisposing factors, concomitant disease profiles, medication history, treatment strategy and associated complications were analyzed.

RESULTS

229 patients were included in the retrospective analysis. A total of 113-type 33 A, 50-type 33 B and 66-type 33 C fractures were diagnosed, of whom 92% received a lateral locking plate osteosynthesis. There was a complication in 14.4% of all cases, of which 6.1% were attributable to infection. Significant risk factors for developing a complication were an increased BMI (29.9 ± 8.5 kg/m2; p = 0.04), fracture displacement of over half a shaft width (p < 0.001) and AOC fractures (p < 0,016), specifically C2 fractures (p < 0,008).

CONCLUSION

In this multicenter retrospective cohort study, lateral locking plate osteosynthesis was the method of choice and was selected in over 90% of cases, regardless of the fracture classification and risk factors. A complication rate of 14.4% emphasizes the necessary analysis of patient- and care-specific risk factors and a resulting adjustment of the therapy strategy. An increased BMI (29.9 ± 8.5 kg/m2; p = 0.04), fracture displacement of over half a shaft width (p < 0.001) and AOC fractures (p < 0,016), specifically C2 fractures (p < 0,008) increase the risk of developing a complication and should prompt an early switch to a treatment strategy that provides more stability.

ACL reconstruction provides superior stability than ACL repair in patients with Schenck III and IV knee joint dislocations: first results of a 12 month follow-up study

PURPOSE

Acute knee dislocation is a rare but devastating multi-ligamentous knee injury with only limited evidence-based surgical technique recommendations. The aim of this study was a comparison of two different anterior cruciate ligament (ACL) restoration techniques as part of an early total surgical care concept: (1) repair of ACL with additional internal bracing (ACLIB) compared to; (2) ACL reconstruction with autograft (ACLR).

METHODS

Retrospective, clinical-study of patients with an acute type III or IV knee dislocation (according to Schenck classification), in which the ACL was treated with ACLIB or ACLR within 12 days. The PCL was sutured and internally braced in all cases. Medial and lateral complex injuries were repaired and additionally laterally augmented by an Arciero reconstruction. After a minimum 12 months follow-up different patient-reported outcome measurements (IKDC, Lysholm, VAS, Tegner Score) and instrumental stability assessment by Rolimeter -test and stress radiographs (Telos™) were analyzed. Groups were compared by t test with p < 0.05 considered significant.

RESULTS

In total, 20 patients (5 IIIM, 5 IIIL and 10 IV) were included in this study with an average follow-up of 13.7 ± 2.6 months. There were significant differences in instrumental stability testing (side-to-side difference (SSD) of anterior tibial translation: ACLIB 2.7 ± 1.5 mm vs. ACLR 1.3 ± 1.3; p = 0.0339) and stress radiography (SSD ACL: ACLIB 3.4 ± 2.2 mm vs. ACLR 0.4 ± 2.7; p = 0.0249) between groups. ACLIB group showed greater ROM in terms of flexion (SSD Flexion: ACLIB 7.8 ± 9.9° vs. ACLR 16 ± 7.0°; p = 0.0466; Total Flexion overall 125.5 ± 11.8°). No clinically relevant differences in patient-reported outcome scores (Lysholm Score: ACLIB 82 ± 16.4 vs. ACLR 85 ± 10.4; IKDC subjective score: ACLIB 70.4 ± 17 vs. ACLR 76.6 ± 8.3) were determined.

CONCLUSION

ACLR provides superior translational stability than ACLIB in terms of instrumental testing and stress radiography. Both techniques were equivalent with respect to PROMS and led to good and excellent clinical results.

LEVEL OF EVIDENCE

Retrospective cohort study, III.

The "hump" a new arthroscopic phenomenon guiding for reliable therapy of osteochondritis dissecans of variable stability status

INTRODUCTION

Despite 150 years of research, there are currently no reliable morphological characteristics that can be used to differentiate between stable and unstable juvenile osteochondritis dissecans (JOCD) lesions in the knee joint. Arthroscopic probing is still the gold standard. In arthroscopic evaluation, a previously undescribed pattern of a cartilaginous convex elevation ("hump") was identified as a new feature and potential sign of JOCD in transition to instability. The aim of the study was to evaluate the clinical outcomes after surgical intervention (drilling) on the "hump".

MATERIALS AND METHODS

In a retrospective case series of sixteen patients with an arthroscopically detectable "hump", the analysis of clinical function scores (Lysholm, Tegner) and morphological MRI monitoring of radiological healing were performed. The assessment of lesion healing was based on pre- and postoperative MRI examinations. The "hump" was defined as an arthroscopically impressive protrusion of the femoral articular surface with a minimally softened, discolored, but intact cartilage margin that, is not mobile upon in the arthroscopic palpation hook test. The primary therapy of choice was drilling of all "humps".

RESULTS

The "hump" could be detected arthroscopically in 16 of 59 JOCD lesions. Specific MRI correlations with the "hump" or arthroscopic unstable lesions could not be detected. Not all "humps" showed signs of MRI-based healing after the drilling, and in some a dissection of the osteochondral flap occurred within the first postoperative year. As a result, secondary refixation became necessary.

CONCLUSION

In the present study, the "hump" was identified as an important differential diagnostic arthroscopic feature of an arthroscopically primarily stable JOCD lesion, potentially placing the lesion at risk of secondary loosening over time. Therefore, drilling alone may not be appropriate in the event of arthroscopic "hump" discovery, but additional fixation may be required to achieve the healing of the lesion.

LEVEL OF EVIDENCE

III.

Nanoscopy and an extended lateral approach can improve the management of latero-central segments in tibial plateau fractures: a cadaveric study

Introduction

The objective of this investigation was to compare different techniques to improve visualization and reduction in tibial plateau fractures involving the central lateral segments.

Methods

Matched pairs of pre-fractured cadaveric tibial plateau fractures that include the central lateral segments were treated by either an anterolateral approach (supine) or PL approach (prone). Reduction was stepwise extended by additional fracturoscopy (FS), nanoscopy (NS) and lastly by epicondyle osteotomy (ECO). Reduction was analyzed by 3D scan and visualization of the lateral plateau was quantified.

Results

Ten specimens (3 pairs 41B3.1, 2 pairs 41C3.3) were analyzed. Fracture steps involving the antero-latero-central (ALC) segment were insufficiently reduced after fluoroscopy using both approaches (AL 2.2 ± 1.2 mm vs PL 2.2 ± 1.0 mm, p 0.95). Additional NS and ECO achieved optimized fracture reduction in the ALC segment (NS AL 1.6 ± 1.3 mm vs PL 0.8 ± 0.9 mm, p 0.32). NS provided visualization of the entire lateral plateau (PL 102.9% ± 7.4, AL 108.8 ± 19.2%), while fracturoscopy only allowed visualization of the ALL segment and partially of PLL and ALC segments (PL 22.0 ± 23.4%, AL 29.7 ± 18.3%).

Conclusion

Optimized reduction of tibial head fractures with involvement of latero-central segments requires additional video-assisted reduction or extended approaches. Nanoscopy helps visualizing of the entire lateral plateau, when compared to fracturoscopy and may become a valuable reduction aid.

Imaging of the medial collateral ligament of the knee: a systematic review

INTRODUCTION

The primary aim of this investigation was to systematically review relevant literature of various imaging modalities (magnetic resonance imaging (MRI), stress radiography and ultrasonography) in the assessment of patients with a medial collateral ligament (MCL) injury.

MATERIALS AND METHODS

A systematic literature review of articles indexed in PubMed and Cochrane library was performed. Original research reporting data associated with medial gapping, surgical, and clinical findings associated with MCL injuries were considered for inclusion. The methodological quality of each inclusion was also assessed using a verified tool.

RESULTS

Twenty-three imaging studies (magnetic resonance imaging (MRI) n = 14; ultrasonography n = 6; radiography n = 3) were ultimately included into the review. A total of 808 injured, and 294 control, knees were assessed. Interobserver reliabilities were reported in radiographic and ultrasonographic investigations with almost perfect agreement. MRI studies demonstrated agreement ranging between substantial to almost perfect. Intraobserver reliability was only reported in radiographic studies pertinent to medial gapping and was found to be almost perfect. Correlation of MRI with clinical findings was moderate to strong (65-92%). Additionally, MRI imaging was more sensitive in the detection of MCL lesions when compared to clinical examination. However, when compared to surgical findings, MRI underestimated the grade of instability in up to 21% of cases. Furthermore, MRI showed relatively inferior performance in the identification of the exact MCL-lesion location when compared to surgical findings. Interestingly, preoperative clinical examination was slightly inferior to stress radiography in the detection of MCL lesions. However, clinical testing under general anaesthesia performed similar to stress radiography. The methodological quality analysis showed a low risk of bias regarding patient selection and index testing in each imaging modality.

CONCLUSION

MRI can reliably diagnose an MCL lesion but demonstrates limitations in its ability to predict the specific lesion location or grade of MCL instability. Ultrasonography is a widely available, radiation free modality, but is rarely used in clinical practice for detecting MCL lesions and clinical or surgical correlates are scarce. Stress radiography findings correlate with surgical findings but clinical correlations are missing in the literature.

LEVEL OF EVIDENCE

IV.

Tibial slope in the posterolateral quadrant with and without ACL injury

INTRODUCTION

An increased tibial slope is a risk factor for rupture of the anterior cruciate ligament. In addition, a tibial bone bruise or posterior lateral impression associated with slope changes also poses chronic ligamentous instability of the knee joint associated with an anterior cruciate ligament (ACL) injury. In the majority of cases, the slope is measured in one plane X-ray in the lateral view. However, this does not sufficient represent the complex anatomy of the tibial plateau and especially for the posterolateral quadrant. Normal values from a "healthy" population are necessary to understand if stability of the knee joint is negatively affected by an increasing slope in the posterolateral area. Until now there are no data about the physiological slope in the posterolateral quadrant of the tibial plateau.

MATERIALS AND METHODS

In 116 MRI scans of patients without ligamentous lesions and 116 MRI scans with an ACL rupture, tibial slope was retrospectively determined using the method described by Hudek et al. Measurements were made in the postero-latero-lateral (PLL) and postero-latero-central (PLC) segments using the 10-segment classification. In both segments, the osseous as well as the cartilaginous slope was measured. Measurements were performed by two independent surgeons.

RESULTS

In the group without ligamentous injury the mean bony PLL slope was 5.8° ± 4.8° and the cartilaginous PLL slope was 6.7° ± 4.8°. In the PLC segment the mean bony slope was 6.6° ± 5.0° and the cartilaginous slope was 9.4° ± 5.7°. In the cohort with ACL rupture, the bony and cartilaginous slope in both PLL and PCL were significantly higher (P < 0.001) than in the group without ACL injury (bony PLL 9.8° ± 4.8°, cartilage PLL 10.4° ± 4.7°, bony PLC 10.3° ± 4.8°, cartilage PLL 12.8° ± 4.3°). Measurements were performed independently by two experienced surgeons. There were good inter- (CI 87-98.7%) and good intraobserver (CI 85.8-99.6%) reliability.

CONCLUSION

The bony and the cartilaginous slope in the posterolateral quadrant of the tibial plateau are different but not independent. Patients with an anterior cruciate ligament injury have a significantly steeper slope in the posterolateral quadrant compared to a healthy group. Our data indicate that this anatomic feature might be a risk factor for a primary ACL injury which has not been described yet.

LEVEL OF EVIDENCE

III.

[Rhabdomyolysis due to drug-drug interaction of atorvastatin and cobicistat]

A 53-year-old man presented with rhabdomyolysis and acute kidney injury. The symptoms were presumably caused by a drug-drug interaction between an antiretroviral drug combination and atorvastatin. As a booster, cobicistat can also increase the toxicity of statins via inhibition of the enzyme cytochrome p450 3A4 (CYP3A4). After stopping atorvastatin and after intravenous fluid therapy, the symptoms regressed completely.

Sex-specific associations between maternal exposure to parabens, phenols and phthalates during pregnancy and birth size outcomes in offspring

Current evidence on the effects of prenatal exposure to endocrine disrupting chemicals on birth size remains largely inconclusive. We aimed to investigate sex-specific associations between maternal exposure to parabens, phenols and phthalates during pregnancy and birth weight, length and head/abdominal circumferences. We performed a prospective study of 88 pregnant women who underwent amniocentesis in the period 2012 to 2014. Maternal urine samples were collected during pregnancy in weeks 12 to 36 (median: 18 weeks). The concentrations of parabens, phenols and individual phthalate diester metabolites were analyzed by isotope-diluted liquid chromatography-tandem mass spectrometry and osmolality adjusted. Linear regression models estimated the associations between urinary levels of selected compounds (tertile(T2-T3)_medium/high versus T1_low exposure) and birth size, stratified by offspring sex. A total of three parabens, two phenols, four individual phthalate metabolites and four sums of diester metabolites were detectable above limits of detection in at least 60% of urine samples. Overall, we observed few statistically significant associations, but medium/high exposure to bisphenol A (BPA) in male offspring was associated with statistically significant lower birth size across most outcomes [birth weight: -428 g (95% CI -756 to -99.4); birth length: -1.76 cm (95% CI -3.28 to -0.25); abdominal circumference: -1.97 cm (95% CI -3.55 to -0.39)]. Similarly, medium/high exposure to methyl paraben (MeP) in male offspring was associated with lower birth weight (-661 g, 95% CI -1251 to -70.7) and length (-3.11 cm, 95% CI -5.76 to -0.46) compared to low exposure. None of these associations were statistically significant in female offspring. Across all compounds, individual exposures were associated with more negative estimates of birth weight for male than for female offspring. Our study indicates that prenatal exposure to BPA and MeP may negatively affect birth size outcomes, with a possible sex effect. Given the small sample size, these findings need to be replicated in future larger studies.

Time- and dose-dependent volume decreases in subcortical grey matter structures of glioma patients after radio(chemo)therapy

•

Radiotherapy causes atrophy of the hippocampus, amygdala, putamen, thalamus and pallidum.

•

Atrophy is dose dependant and progressive over time.

•

The hippocampus shows the highest atrophy rates at a given mean dose and time.

•

The caudate shows no significant atrophy.

Background and purpose

Radiotherapy (RT) is an adjuvant treatment option for glioma patients. Side effects include tissue atrophy, which might be a contributing factor to neurocognitive decline after treatment. The goal of this study was to determine potential atrophy of the hippocampus, amygdala, thalamus, putamen, pallidum and caudate nucleus in glioma patients having undergone magnetic resonance imaging (MRI) before and after RT.

Materials and methods

Subcortical volumes were measured using T1-weighted MRI from patients before RT (N = 91) and from longitudinal follow-ups acquired in three-monthly intervals (N = 349). The volumes were normalized to the baseline values, while excluding structures touching the clinical target volume (CTV) or abnormal tissue seen on FLAIR imaging. A multivariate linear effects model was used to determine if time after RT and mean RT dose delivered to the corresponding structures were significant predictors of tissue atrophy.

Results

The hippocampus, amygdala, thalamus, putamen, and pallidum showed significant atrophy after RT as function of both time after RT and mean RT dose delivered to the corresponding structure. Only the caudate showed no dose or time dependant atrophy. Conversely, the hippocampus was the structure with the highest atrophy rate of 5.2 % after one year and assuming a mean dose of 30 Gy.

Conclusion

The hippocampus showed the highest atrophy rates followed by the thalamus and the amygdala. The subcortical structures here found to decrease in volume indicative of radiosensitivity should be the focus of future studies investigating the relationship between neurocognitive decline and RT.

The Cleft-screen-questionnaire (CSQ) - A validated screening instrument for health-related quality of life in cleft patients

BACKGROUND

The objective of this study is to develop and validate a specific screening instrument for assessing the quality of life (QoL) of patients with orofacial clefts. The Cleft-Screen-Questionnaire (CSQ) aims at identifying the main problematic areas and is intended for the routine use in everyday clinical practice to constantly evaluate the conditions' and treatments' effects on patients' well-being.

METHODS

First, a pool of 58 questions is created by collecting items from validated questionnaires previously used for assessing the QoL in cleft populations. After the removal of duplicate questions, the questionnaires are answered by 152 patients from a tertiary care center. A factor analysis followed by the calculation of Cronbach's alpha as a reliability measurement led to the final CSQ presented here.

RESULTS

The applied factor analysis resulted in five factors. Items showing low factor loadings (seen as <0.5) were excluded initially. Accordingly, factor analysis led to a preliminary number of 43 items. A reliability analysis using Cronbach's alpha and corrected alpha if item deleted showed an overall moderate to high reliability (seen as: 0.6-0.9). After excluding questions with increasing alphas if item deleted, analyses yielded in a final number of 38 questions.

CONCLUSION

The final 38-item CSQ is a reliable instrument for evaluating the health-related QoL of cleft patients.

Additional lateral extra-articular tenodesis in revision ACL reconstruction does not influence the outcome of patients with low-grade anterior knee laxity

INTRODUCTION

There is limited evidence on the indications of lateral extra-articular tenodesis (LET) in revision ACLR. The aim of this study was to evaluate the influence of the LET in patients with revision ACLR with preoperative low-grade anterior knee laxity.

METHODS

Between 2013 and 2018, 78 patients who underwent revision ACLR with preoperative low-grade anterior knee laxity [≤ 5 mm side-to-side difference (SSD)] were included in the retrospective cohort study. An additional modified Lemaire tenodesis was performed in 23 patients during revision ACLR and patients were clinically examined with a minimum of 2 years after revision surgery. Postoperative failure of the revision ACLR was defined as SSD in Rolimeter^® testing ≥ 5 mm or pivot-shift grade 2/3.

RESULTS

In total, failure of the revision ACLR occurred in 11.5% (n = 9) of the cases at a mean follow-up of 28.7 ± 8.8 (24-67) months. Patients with an additional LET and revision ACLR did not show a significantly reduced failure rate (13% vs. 11%) or an improved clinical outcome according to the postoperative functional scores or pain in regards to patients with an isolated revision ACLR (Tegner 5.7 ± 1.3 vs. 5.9 ± 1.5, n.s.; IKDC 77.5 ± 16.2 vs. 80.1 ± 14.9, n.s., Lysholm 81.9 ± 14.2 vs. 83.8 ± 14.5, n.s.; VAS 1.9 ± 2.2 vs. 1.2 ± 1.7, n.s.).

CONCLUSIONS

An additional LET in patients with revision ACLR with low-grade anterior knee laxity does not influence patient-related outcomes or failure rates. Subjects with preoperative low-grade anterior knee laxity may not benefit from a LET in revision ACLR.

LEVEL OF EVIDENCE

III.

Presence of parabens, phenols and phthalates in paired maternal serum, urine and amniotic fluid

OBJECTIVE

To examine whether selected endocrine disrupting chemicals were present in pregnant women and passed through the placental barrier to amniotic fluid, potentially exposing the developing fetus.

METHODS

Paired samples of maternal serum, urine and amniotic fluid were concurrently collected (<1 h) from 200 pregnant women (age >18 years) with a singleton pregnancy and undergoing amniocentesis between gestational weeks 12 - 36. The concentration of six different parabens, seven phenols, 31 metabolites from 15 phthalate diesters and the polychlorinated substance triclocarban were analyzed by isotope diluted TurboFlow-liquid chromatography-tandem mass spectrometry.

RESULTS

Concentrations of all included compounds were highest in maternal urine followed by serum, and lowest in amniotic fluid. Of the six parabens measured in amniotic fluid, methylparaben (MeP) and ethylparaben (EtP) were detectable most often (87% and 33% of the samples, respectively). Of the seven phenols measured, three (2,4-dichlorphenol, 2,5-dichlorphenol, 2-propylphenol) were detectable in the range of 14-21% of the amniotic fluid samples, at low concentrations (<0.12 ng/ml). Two secondary phthalates metabolites, mono-(2-carboxymethyl-hexyl) phthalate and mono-carboxy-iso-octyl phthalate were each present in ≤15% of the amniotic fluid samples at concentrations 2-5 times lower than in maternal serum and 20-100 times lower than in maternal urine. A modest statistically significant correlation between the levels of MeP and EtP was detected in paired maternal urine-amniotic fluid samples was detected (Spearman r_MeP: 0.246; r_EtP: 0.364). Likewise, the concentration of mono-ethyl phthalate (MEP) in paired maternal urine and amniotic fluid samples indicated a modest statistically significant correlation (Spearman r_MEP: 0.264), driven by detectable levels of MEP in only 3% of the amniotic fluid samples.

CONCLUSIONS

In general, the included parabens, phenols and phthalates were effectively metabolized and excreted via the urine, which was the matrix that reflected the highest detectable levels. The detectable levels of several included parabens and phthalates in human amniotic fluid calls for further investigations of the toxicokinetic and potential endocrine disrupting properties of individual and multiple endocrine disruptors in order to better assess the risk to the developing fetus.

Integration of radiation oncology teaching in medical studies by German medical faculties due to the new licensing regulations : An overview and recommendations of the consortium academic radiation oncology of the German Society for Radiation Oncology (DEGRO)

The new Medical Licensing Regulations 2025 (Ärztliche Approbationsordnung, ÄApprO) will soon be passed by the Federal Council (Bundesrat) and will be implemented step by step by the individual faculties in the coming months. The further development of medical studies essentially involves an orientation from fact-based to competence-based learning and focuses on practical, longitudinal and interdisciplinary training. Radiation oncology and radiation therapy are important components of therapeutic oncology and are of great importance for public health, both clinically and epidemiologically, and therefore should be given appropriate attention in medical education. This report is based on a recent survey on the current state of radiation therapy teaching at university hospitals in Germany as well as the contents of the National Competence Based Learning Objectives Catalogue for Medicine 2.0 (Nationaler Kompetenzbasierter Lernzielkatalog Medizin 2.0, NKLM) and the closely related Subject Catalogue (Gegenstandskatalog, GK) of the Institute for Medical and Pharmaceutical Examination Questions (Institut für Medizinische und Pharmazeutische Prüfungsfragen, IMPP). The current recommendations of the German Society for Radiation Oncology (Deutsche Gesellschaft für Radioonkologie, DEGRO) regarding topics, scope and rationale for the establishment of radiation oncology teaching at the respective faculties are also included.

Selective inhibition of the PI3K isoform p110alpha using BYL719 protects against tyrosine kinase-mediated processes in PASMCs and reduces experimental pulmonary hypertension in mice and rats

Rationale

Pulmonary arterial hypertension (PAH) is a vascular disease characterized by chronic increases in pulmonary vascular resistance (PVR), pulmonary arterial pressure (PAP), and right ventricular (RV) hypertrophy. Increased activation of receptor tyrosine kinase (RTK) -mediated signaling pathways leads to increased proliferation and migration of pulmonary smooth vascular muscle cells (PASMCs) which promote vascular remodeling processes. We identified the catalytic subunit p110alpha of phosphatidylinositol-3-kinase as a key enzyme for these processes and showed that both genetic ablation of p110alpha in SMCs and pharmacological inhibition can prevent experimental PH. Here, the effects of the orally bioavailable p110alpha selective PI3K inhibitor BYL719 on the RTK-mediated proliferation and chemotaxis of PASMCs, as well as the effects in the hypoxia-induced mouse and in the Sugen / hypoxia (SuHx) -induced rat model of PH were investigated.

Methods

Human and murine PASMCs were pretreated with different concentrations of BYL719 and stimulated with a mixture of growth factors (PDGF [30ng/ml], EGF [0,5ng/ml], bFGF [2ng/ml], insulin [0,5ng/ml], and FBS [5%]). Proliferation was investigated using a BrdU incorporation ELISA assay (Roche). Chemotaxis was quantified using modified Boyden chambers.

Male BL/6 mice were subjected to hypoxia (10% O2) for 21 days. Treatment with BYL719 (or vehicle) was carried out via daily gavage of 50mg/kg bodyweight.

In addition, a therapeutic approach was investigated using male Sprague Dawley rats in the SuHx model, which were treated with BYL719 (20 mg / kg body weight) or vehicle for 2 weeks after a three-week hypoxia phase. The RV pressure (RVSP) was measured using a Millar® or liquid-filled catheter. The RV hypertrophy is shown as the quotient of the weights of the RV to the LV + septum (RV / (LV + S)).

Results

Growth factor-induced proliferation and chemotaxis of the PASMCs were significantly and concentration-dependently inhibited by BYL719. The exposure to hypoxia led to an increase of the RVSP (24.5±0.95 to 35.2±1.28 mmHg) and the development of right ventricular hypertrophy (RV / LV + S 0.24±0.01 to 0.37±0.073), which was significantly reduced in the BYL719 treated group (RVSP 31.4±0.53 mmHg; RV / LV + S 0.31±0.01) (p&lt;0.05). In addition, SuHx led to a robust increase of the RVSP (129.2±5.4 mmHg) and pronounced RV hypertrophy (RV / (LV + S): 0.86±0.04), which were significantly reduced by the therapeutic BYL719 treatment (102.0±6.1 mmHg or 0.64±0.03).

Conclusion

These results show that inhibition of p110alpha using the BYL719 reduced growth factor-mediated pathological processes in PASMCs in vitro, as well as hypoxia-induced (mouse) and already established SuHx-induced PH (rat). Thus, the inhibition of p110a using BYL719 represents a promising approach for the treatment of PAH.

Funding Acknowledgement

Type of funding sources: None.

Reduced diffusion in white matter after radiotherapy with photons and protons

BACKGROUND AND PURPOSE

Radio(chemo)therapy is standard in the adjuvant treatment of glioblastoma. Inevitably, brain tissue surrounding the target volume is also irradiated, potentially causing acute and late side-effects. Diffusion imaging has been shown to be a sensitive method to detect early changes in the cerebral white matter (WM) after radiation. The aim of this work was to assess possible changes in the mean diffusivity (MD) of WM after radio(chemo)therapy using Diffusion-weighted imaging (DWI) and to compare these effects between patients treated with proton and photon irradiation.

MATERIALS AND METHODS

70 patients with glioblastoma underwent adjuvant radio(chemo)therapy with protons (n = 20) or photons (n = 50) at the University Hospital Dresden. MRI follow-ups were performed at three-monthly intervals and in this study were evaluated until 33 months after the end of therapy. Relative white matter MD changes between baseline and all follow-up visits were calculated in different dose regions.

RESULTS

We observed a significant decrease of MD (p < 0.05) in WM regions receiving more than 20 Gy. MD reduction was progressive with dose and time after radio(chemo)therapy (maximum: -7.9 ± 1.2% after 24 months, ≥50 Gy). In patients treated with photons, significant reductions of MD in the entire WM (p < 0.05) were seen at all time points. Conversely, in proton patients, whole brain MD did not change significantly.

CONCLUSIONS

Irradiation leads to measurable MD reduction in white matter, progressing with both increasing dose and time. Treatment with protons reduces this effect most likely due to a lower total dose in the surrounding white matter. Further investigations are needed to assess whether those MD changes correlate with known radiation induced side-effects.

Overestimation of grey matter atrophy in glioblastoma patients following radio(chemo)therapy

Objective

Brain atrophy has the potential to become a biomarker for severity of radiation-induced side-effects. Particularly brain tumour patients can show great MRI signal changes over time caused by e.g. oedema, tumour progress or necrosis. The goal of this study was to investigate if such changes affect the segmentation accuracy of normal appearing brain and thus influence longitudinal volumetric measurements.

Materials and methods

T1-weighted MR images of 52 glioblastoma patients with unilateral tumours acquired before and three months after the end of radio(chemo)therapy were analysed. GM and WM volumes in the contralateral hemisphere were compared between segmenting the whole brain (full) and the contralateral hemisphere only (cl) with SPM and FSL. Relative GM and WM volumes were compared using paired t tests and correlated with the corresponding mean dose in GM and WM, respectively.

Results

Mean GM atrophy was significantly higher for full segmentation compared to cl segmentation when using SPM (mean ± std: ΔV_GM,full = − 3.1% ± 3.7%, ΔV_GM,cl = − 1.6% ± 2.7%; p < 0.001, d = 0.62). GM atrophy was significantly correlated with the mean GM dose with the SPM cl segmentation (r = − 0.4, p = 0.004), FSL full segmentation (r = − 0.4, p = 0.004) and FSL cl segmentation (r = -0.35, p = 0.012) but not with the SPM full segmentation (r = − 0.23, p = 0.1).

Conclusions

For accurate normal tissue volume measurements in brain tumour patients using SPM, abnormal tissue needs to be masked prior to segmentation, however, this is not necessary when using FSL.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10334-021-00922-3.

UV filters in matched seminal fluid-, urine-, and serum samples from young men

Recent in vitro studies have shown that some chemical UV filters mimic the effect of progesterone in the activation of the CatSper Ca2⁺ channel in human spermatozoa. However, so far, the extent of exposure of human spermatozoa to chemical UV filters via the presence of these chemicals in seminal fluid has been unknown. Here, we present levels of UV filters measured in human seminal fluid and comparisons to levels measured in concurrently collected urine and serum samples. In total nine UV filters were analysed by TurboFlow-LC-MS/MS in paired urine, serum, and seminal fluid samples from 300 young Danish men from the general population; each man collected one of each sample type within 1 h. The samples were collected during February-December 2013 and only six of the men reported having used sunscreen during the 48 h preceding the sample collection. Four of the examined UV filters could be detected in seminal fluid samples at levels above LOD in more than 10% of the samples. Benzophenone (BP), benzophenone-1 (BP-1), and benzophenone-3 (BP-3) were most frequently detected in, respectively, 18%, 19%, and 27% of the seminal fluid samples albeit at levels one to two orders of magnitude lower than the levels observed in urine. 4-methyl-benzophenone (4-MBP) was detectable in 11% of the seminal fluid samples while in <5% of the urine samples. Overall 45% of the men had at least one of the UV filters present in their seminal fluid at detectable levels. For BP-1 and BP-3 individual levels in urine and seminal fluid were significantly correlated, while this was not evident for BP nor 4-MBP. In conclusion, chemical UV filters are present in men's seminal fluid; some of which can activate the human sperm-specific CatSper Ca²⁺ channel and thereby potentially interfere with the fertilisation process.

The upgraded TOMAS device: A toroidal plasma facility for wall conditioning, plasma production, and plasma-surface interaction studies

The Toroidal Magnetized System device has been significantly upgraded to enable development of various wall conditioning techniques, including methods based on ion and electron cyclotron (IC/EC) range of frequency plasmas, and to complement plasma-wall interaction research in tokamaks and stellarators. The toroidal magnetic field generated by 16 coils can reach its maximum of 125 mT on the toroidal axis. The EC system is operated at 2.45 GHz with up to 6 kW forward power. The IC system can couple up to 6 kW in the frequency range of 10 MHz-50 MHz. The direct current glow discharge system is based on a graphite anode with a maximum voltage of 1.5 kV and a current of 6 A. A load-lock system with a vertical manipulator allows exposure of material samples. A number of diagnostics have been installed: single- and triple-pin Langmuir probes for radial plasma profiles, a time-of-flight neutral particle analyzer capable of detecting neutrals in the energy range of 10 eV-1000 eV, and a quadrupole mass spectrometer and video systems for plasma imaging. The majority of systems and diagnostics are controlled by the Siemens SIMATIC S7 system, which also provides safety interlocks.

FSHB and FSHR gene variants exert mild modulatory effect on reproductive hormone levels and testis size but not on semen quality: A study of 2020 men from the general Danish population

BACKGROUND

Spermatogenesis depends on stimulation by follicle-stimulating hormone (FSH) which binds to FSH receptors (FSHR) on testicular Sertoli cells. Three FSH-related single-nucleotide polymorphisms (SNPs), FSHB -211G>T (rs10835638), FSHR -29G>A (rs1394205) and FSHR 2039A>G (rs6166) affect FSH action, and have been suggested to affect testicular function, but the evidence is uncertain.

OBJECTIVE

To describe the associations between the three SNPs and testicular function in a large and well-characterised cohort of men from the general population.

MATERIALS AND METHODS

A cross-sectional study of 2020 Danish men unselected regarding testicular function. Outcome variables were semen parameters, reproductive hormones and testis size. Genotyping was done by competitive allele-specific quantitative PCR. Differences in genotype frequencies were tested by chi-square test and associations between genotypes and outcomes were assessed by multivariate linear regressions.

RESULTS

The SNPs affected serum FSH; carriers of the variant affecting FSH secretion (FSHB -211G>T) had lower FSH levels while carriers of variants affecting receptor expression (FSHR -29G>A) and receptor sensitivity (FSHR 2039A>G) had higher FSH levels. Carriers of FSHB -211G>T had lower calculated free testosterone/LH ratio. Although both FSHB -211G>T and FSHR 2039A>G were associated with smaller testis size, no clear association was detected in relation to any semen parameters, except a lower total number of morphologically normal spermatozoa in the heterozygous carriers of the FSHB -211G>T DISCUSSION AND CONCLUSION: The studied polymorphisms have only minor modulating influence on testis size and function in healthy men. We detected subtle effects of the three SNPs on FSH levels, but also effects of FSHB -211G>T on calculated free testosterone/LH ratio, compatible with altered Leydig cell function. Thus, the role of these FSH-related polymorphisms is complex and modest in men with normal testicular function, but the possible importance of FSH polymorphisms in men with impaired testicular function should be evaluated in future studies in more detail.

Factors influencing GPs' perception of specialised palliative homecare (SPHC) importance - results of a cross-sectional study

Background

General Practitioners (GPs) are the main providers of primary palliative care (PPC). At the same time they are the main initiators of specialised palliative homecare (SPHC). In Germany, little is known about factors which influence GPs in their involvement of SPHC. Aim of our study is to identify factors that drive GPs to give value to and involve SPHC.

Methods

A cross-sectional survey was performed. In 2018, questionnaires were mailed to 6000 randomly selected GPs from eight German federal states, focusing on the extent of GPs’ palliative care activities and their involvement of SPHC.

Results

With a response rate of 19.4% and exclusion of GPs working in SPHC-teams, n = 1026 questionnaires were appropriate for analysis. GPs valued SPHC support as the most “important/very important” for both “technical/invasive treatment measures” (95%) and availability outside practice opening hours (92%).

The most relevant factor influencing perceived SPHC-importance was GPs’ self-reported extent of engagement in palliative care (β = − 0.283; CI 95% = − 0.384;−0.182), followed by the perceived quality of utilised SPHC (β = 0.119; CI 95% = 0.048;0.190), involvement in treatment of palliative patients after SPHC initiation (β = 0.088; CI 95% = 0.042;0.134), and conviction that palliative care should be a central part of GPs’ work (β = − 0.062; CI 95% = − 0.116;−0.008). Perceived SPHC-importance is also associated with SPHC-referrals (β =0.138; p < 0.001). The lower the engagement of GPs in palliative care, the more they involve SPHC and vice versa.

Conclusions

GPs with low reported activity in palliative care are more likely to initialise SPHC for palliative care activities they do not deliver themselves for various reasons, which might mean that the involvement of SPHC is substitutive instead of complementary to primary palliative care. This finding and its interpretation should be given more attention in the future policy framework for (specialised) palliative homecare.

Trial registration

German Clinical Trials Register DRKS00014726, 14.05.2018.

Use of stored serum in the study of time trends and geographical differences in exposure of pregnant women to phthalates

BACKGROUND

Exposure to some phthalate diesters has been associated with adverse reproductive health outcomes in both rodents and humans indicative of anti-androgenic effects. Exposure during sensitive periods of development, such as prenatally, is of particular concern.

OBJECTIVES

We wished to investigate whether phthalate metabolites measured in maternal serum samples from historical birth cohorts can be used to assess prenatal exposure. Further, we aimed to study temporal and geographical trends in phthalate exposure across three different birth cohorts.

METHODS

We compared phthalate metabolite levels in maternal serum samples from an Australian (1989-91) and a Danish (1997-2001) birth cohort with levels in serum and urine samples from a recent Danish birth cohort (2012-14). Samples were analysed for 32 phthalate metabolites from 15 phthalate diesters by isotope-diluted liquid chromatography-tandem mass spectrometry (LC-MS/MS). Correlations between metabolites were tested by Spearman rank correlation test, and differences between the cohorts were tested by Mann-Whitney U test.

RESULTS

Overall, we observed large variations in serum phthalate metabolite levels between individuals. Secondary metabolites of di-(2-ethyl-hexyl) phthalate (DEHP) and di-iso-nonyl phthalate (DiNP) in serum were weakly to moderately and positively correlated to the levels measured in urine, and secondary metabolites of DEHP were also moderately to strongly and significantly correlated in serum. Correlations with mono-(2-ethyl-hexyl) phthalate (MEHP) and mono-iso-nonyl phthalate (MiNP), the two primary metabolites of DEHP and DiNP, were inconsistent, and we found indications of sample contamination. We observed some significant differences in phthalate metabolite levels between the three cohorts with generally higher levels in the older birth cohorts.

CONCLUSION

Based on comparison across two older birth cohorts and a recent cohort, our results support the concept that historical biobanked serum samples may be used for assessment of prenatal exposure to phthalates when using serum levels of the monoesters of the low-molecular weight (LMW) phthalates and the secondary metabolites of the high-molecular weight (HMW) phthalates. Serum phthalate measurements are, however, not suitable for human biomonitoring and should only be used to exploit historical samples from cohorts, where urine samples were not collected. Our findings suggest that phthalate exposure may have decreased over time from the early 1990s to the 2010s.

A Monte Carlo based radiation response modelling framework to assess variability of clinical RBE in proton therapy

The clinical implementation of a variable relative biological effectiveness (RBE) in proton therapy is currently controversially discussed. Initial clinical evidence indicates a variable proton RBE, which needs to be verified. In this study, a radiation response modelling framework for assessing clinical RBE variability is established. It was applied to four selected glioma patients (grade III) treated with adjuvant radio(chemo)therapy and who developed late morphological image changes on T1-weighted contrast-enhanced (T1w-CE) magnetic resonance (MR) images within approximately two years of recurrence-free follow-up. The image changes were correlated voxelwise with dose and linear energy transfer (LET) values using univariable and multivariable logistic regression analysis. The regression models were evaluated by the area-under-the-curve (AUC) method performing a leave-one-out cross validation. The tolerance dose TD₅₀ at which 50% of patient voxels experienced toxicity was interpolated from the models. A Monte Carlo (MC) model was developed to simulate dose and LET distributions, which includes variance reduction (VR) techniques to decrease computation time. Its reliability and accuracy were evaluated based on dose calculations of the clinical treatment planning system (TPS) as well as absolute dose measurements performed in the patient specific quality assurance. Morphological image changes were related to a combination of dose and LET. The multivariable models revealed cross-validated AUC values of up to 0.88. The interpolated TD₅₀ curves decreased with increasing LET indicating an increase in biological effectiveness. The MC model reliably predicted average TPS dose within the clinical target volume as well as absolute water phantom dose measurements within 2% accuracy using dedicated VR settings. The observed correlation of dose and LET with late brain tissue damage suggests considering RBE variability for predicting chronic radiation-induced brain toxicities. The MC model simulates radiation fields in patients precisely and time-efficiently. Hence, this study encourages and enables in-depth patient evaluation to assess the variability of clinical proton RBE.

Enumeration of Probiotic Bacilli Spores in Animal Feed: Interlaboratory Study

Fourteen out of 17 laboratories completed an interlaboratory study comparing 2 pretreatment protocols of feed samples containing authorized probiotic bacilli spores. Both methods used tryptone soy agar for enumeration. Pretreatment A involved preparation of a suspension of the feed sample in 50% ethanol. For pretreatment B, the sample was suspended in peptone salt solution and heated at 80°C for 10 min. Each laboratory analyzed 12 samples (6 per pretreatment), which represented duplicates of a high (109 colony-forming units [CFU]/g) and low (105 CFU/g) level of bacilli spores or a blank that contained vegetative probiotic bacteria only. For pretreatment A, the re-peatability relative standard deviation (RSDr) was 2.9% for the low level and 2.5% for the high. The reproducibility relative standard deviation (RSDR) values were 7.8 and 5.9%, respectively. Pretreatment B revealed RSDr values of 1.1 and 1.0%, and RSDR values of 5.8 and 3.4%, respectively. The heat treatment (pretreatment B) of feed samples had better precision data, resulted in higher viable bacilli counts, and was more effective in deactivating vegetative background flora. It is therefore recommended for adoption for official control purposes and for CEN and ISO standards.

Enumeration of Probiotic Pediococci in Animal Feed: Interlaboratory Study

An enumeration method to be used as official control under Council Directive 70/524/EEC for probiotic pediococci used as feed additives was validated for consideration for adoption as Comitée Européen de Normalisation (CEN) and ISO standards. Seventeen laboratories in 11 European countries carried out an interlaboratory study. A spread plate method following BS ISO 15214:1998 using 4 different agars [MRS, acidified MRS, MRS with triphenyl tetrazolium chloride (TTC), and a newly developed pediococci selective medium (PSM)] was validated. Precision data in terms of repeatability (r) and reproducibility (R) of the method for each medium using different feeding stuffs with a high and a low inoculation level were determined. Pediococci were present in the samples in mixtures with other probiotics. The enumeration of pediococci on all agars showedan RSDr value of 0.4–3.1% and an RSDR of 1.3–4.8%. MRS agar was preferred, followed by acidified MRS and MRS + TTC agar. All 4 media gave similar counts. Depending on the presence and concentration of other probiotic, such as enterococci, lactobacilli, and yeast, acidified MRS or MRS + TTC agar are recommended. The PSM was selective for pediococci and can be used if this species is present at a concentration more than 10-fold lower than other species that can grow on the MRS agars. The methodology with all 4 media is not applicable to mineral feed.

Method of Determination of Appropriate Heat Treatment of Animal Meal by Immunoassay Developed for Detection of Cooked Beef: Interlaboratory Study

An interlaboratory trial was conducted for the validation of an enzyme-linked immunosorbent assay (ELISA) method for determination of appropriate heat treatment of animal meal. A commercially available ELISA test kit developed for the identification of beef in cooked food was used in the study. Twelve laboratories from 7 European countries examined 2 different analytical protocols to establish the most appropriate analytical method. Three different samples were used, 2 animal waste materials sterilized at 129 and 134°C (wet conditions), respectively, and a meat and bone meal material processed at dry conditions (maximum temperature, 140°C). Statistical evaluation applying t-statistics showed that the animal meal treated according to European legislation (&gt;133°C) was clearly distinguishable from the 2 other test materials at a 99% confidence level using both analytical protocols. This method can be considered as a complementary test to the immunoassay developed for the detection of pork in cooked food that is already applied in routine analysis for the surveillance of rendering plants.