Prevention of legionella infections from toilet flushing cisterns

INTRODUCTION

Immunocompromised patients are at an increased risk of severe legionella infections. We present the results of an outbreak investigation initiated following a fatal case of hospital-acquired legionellosis linked to contaminated water from a toilet-flushing cistern. Additionally, we provide experimental data on the growth of Legionella spp. in flushing cisterns and propose a straightforward protocol for prevention.

METHODS

We monitored the growth of Legionella spp. in the building's hot- and cold-water systems using quantitative bacterial culture on selective agar. Molecular typing of Legionella pneumophila isolates from the infected patient and the water system was conducted through core-genome multi-locus sequence typing (cgMLST).

RESULTS

Legionella contamination in the hospital building's cold-water system was significantly higher than in the hot-water system and significantly higher in toilet flushing cistern's water compared with cold water from bathroom sinks and showers. Isolates from the patient and from the flushing cistern of the patient's bathroom were identical by cgMLST. In an experimental setting, daily toilet flushing for a period of 21 days resulted in a 67% reduction in the growth of Legionella spp. in the water of toilet flushing cisterns. Moreover, a one-time disinfection of cisterns with peracetic acid, followed by daily flushing, decreased legionella growth to less than 1% over a period of at least seven weeks in these setting.

CONCLUSIONS

One-time disinfection of highly contaminated cisterns with peracetic acid and daily toilet flushing as short-term measure can significantly reduce legionella contamination in flushing cisterns. These measures may aid in preventing legionella infection among immunocompromised patients.

HER2 copy number determination in breast cancer using the highly sensitive droplet digital PCR method

Human epidermal growth factor receptor 2 (HER)-positive breast cancer (BC) is characterized by an aggressive clinical course. In the case of HER2 overexpression/amplification, patients benefit from HER2-targeting therapies. Standardized diagnostic HER2 assessment includes immunohistochemistry (IHC) and/or in situ hybridization (ISH). The aim of this study was to compare this "gold standard" with the Droplet Digital™ polymerase chain reaction (ddPCR), a method that allows sensitive and precise detection of copy number variations (CNV) in FFPE (formalin-fixed, paraffin-embedded) DNA samples. Partitioning of the PCR reaction into 20,000 droplets enables a precise quantitative "CN" discrimination also in heterogeneous samples. FFPE breast cancer samples (n = 170) with routinely assessed HER2 status by IHC/ISH were retrospectively analyzed using the ddPCR CNV ERBB2 assay. Comparison of HER2 status assessment by the two methods revealed concordant results in 92.9% (158/170) of the cases. Discrepant cases were verified and interpreted. For ddPCR, a cut off value of 3 HER2 copies was set to distinguish between HER2-negative and HER2-positive BC. Results obtained with the ddPCR CNV ERBB2 assay were consistent and reproducible, and serial dilutions demonstrated a high stability and sensitivity of the method. The ddPCR CNV ERBB2 assay may be a specific and convenient tool to quantify HER2 copy numbers in BC samples. In our study, this method showed high reproducibility in accuracy of HER2 assessment compared to IHC/ISH analysis.

A - 75 Neuropsychological Consequences of Anoxic Encephalopathy Pursuant to Myocardial Infarction

OBJECTIVE

Myocardial infarctions (MI) often result in irreversible muscle damage to the heart and difficulty returning to daily activities. While the physical consequences of acute cardiac events are well documented in the medical literature (Lesperance et al., 1996), there is less research identifying the cognitive, emotional, and behavioral consequences of MI (Brink et al., 2008) particularly when complicated by anoxia and unresponsiveness.

METHOD

We present a case study of a 54-year-old right-handed male with 12 years of education referred for neuropsychological assessment pursuant to mental status changes following a MI with an estimated 25-30 minutes of unresponsiveness and subsequent diagnosis of anoxic encephalopathy, supported by neuroimaging, which is also positive for a 4 mm pituitary tumor.

RESULTS

Neuropsychological assessment revealed difficulties with cognitive efficiency, sequencing, language production, phonemic fluency, and memory. Performance was also inconsistent with age- and education-weighted norms, and therefore did not reflect a normal aging profile. An objective psychological inventory (PAI) revealed negative self-evaluation, a focus on health matters, acute stress, and substance concerns. Additionally, an endorsement of social isolation, discomfort in social interactions, and a readiness to express anger verbally was indicated. Findings supported diagnosis of cognitive impairment associated with anoxic brain injury from above noted MI.

CONCLUSION

This case provides an example of the neuropsychological consequences of anoxic encephalopathy from MI on cognitive, emotional and behavioral functioning. It also supports the need for awareness of bodily health within the context of overall cognitive health. It emphasizes the benefits of integrating physiological and neurocognitive symptoms when conceptualizing patients with cardiac arrest.

The relevance of reducing Veress needle overshooting

Safe insertion of the Veress needle during laparoscopy relies on the surgeons' technical skills in order to stop needle insertion just in time to prevent overshooting in the underlying organs. To reduce this risk, a wide variety of Veress needle systems were developed with safety mechanisms that limit the insertion speed, insertion depth or decouple the driving force generated by the surgeon's hand on the needle. The aim of this study is to evaluate current surgeons' perceptions related to the use of Veress needles and to investigate the relevance of preventing overshooting of Veress needles among members of the European Association of Endoscopic Surgery (EAES). An online survey was distributed by the EAES Executive Office to all active members. The survey consisted of demographic data and 14 questions regarding the use of the Veress needle, the training conducted prior to usage, and the need for any improvement. A total of 365 members residing in 58 different countries responded the survey. Of the responding surgeons, 36% prefer the open method for patients with normal body mass index (BMI), and 22% for patients with high BMI. Of the surgeons using Veress needle, 68% indicated that the reduction of overshoot is beneficial in normal BMI patients, whereas 78% indicated that this is beneficial in high BMI patients. On average, the members using the Veress needle had used it for 1448 (SD 3031) times and felt comfortable on using it after 22,9 (SD 78,9) times. The average years of experience was 17,6 (SD 11,1) and the surgeons think that a maximum overshoot of 9.4 (SD 5.5) mm is acceptable before they can safely use the Veress needle. This survey indicates that despite the risks, Veress needles are still being used by the majority of the laparoscopic surgeons who responded. In addition, the surgeons responded that they were interested in using a Veress needle with an extra safety mechanism if it limits the risk of overshooting into the underlying structures.

Comparison of the efficacy of manual treatment according to fascial distortion model versus joint mobilization in patients with shoulder impingement: A randomized clinical trial

BACKGROUND

The Fascial Distortion Model (FDM) is a relatively new manual therapy approach in the field of musculoskeletal physical therapy, but to date no study has been conducted to compare its' effect in comparison with joint mobilization on patients with shoulder impingement syndrome.

OBJECTIVE

The present study aims to compare the efficacy of the FDM versus joint mobilization in pain intensity, pain-free abduction range of motion and function of patients with shoulder impingement syndrome.

DESIGN

single-blind, parallel-arm randomized controlled trial.

METHODS

26 patients diagnosed with shoulder impingement syndrome were equally randomized into 2 groups: manual treatment according to the FDM, and joint mobilization of the shoulder complex. All patients received 3 intervention sessions every other day. Pain intensity (by visual analogue scale), pain-free abduction range of motion (by goniometry) and function (by Persian version of shoulder pain and disability index) were measured before and after every session and at follow-up 2 weeks later. Patients' satisfaction with treatment was also measured (by a 4-point Likert scale) at follow-up.

RESULTS

FDM therapy group showed statistically significant greater pain reduction (P = 0.014) and range of motion increment (P = 0.044) than joint mobilization group after intervention, while only range of motion maintained the difference at follow-up (P = 0.034). Function improvement was not statistically different after the intervention (P = 0.582) and at follow-up (P = 0.094). There was no difference in patients' satisfaction with treatment between groups (P > 0.05).

CONCLUSION

The FDM is a safe and effective treatment approach with comparable results to joint mobilization in patients with shoulder impingement syndrome.

Sensitivity, specificity, and diagnostic accuracy of WHO 2013 criteria for diagnosis of gestational diabetes mellitus in low risk early pregnancies: international, prospective, multicentre cohort study

Objective

To evaluate the predictability of gestational diabetes mellitus wth a 75 g oral glucose tolerance test (OGTT) in early pregnancy, based on the 2013 criteria of the World Health Organization, and to test newly proposed cut-off values.

Design

International, prospective, multicentre cohort study.

Setting

Six university or cantonal departments in Austria, Germany, and Switzerland, from 1 May 2016 to 31 January 2019.

Participants

Low risk cohort of 829 participants aged 18-45 years with singleton pregnancies attending first trimester screening and consenting to have an early 75 g OGTT at 12-15 weeks of gestation. Participants and healthcare providers were blinded to the results.

Main outcome measures

Fasting, one hour, and two hour plasma glucose concentrations after an early 75 g OGTT (12-15 weeks of gestation) and a late 75 g OGTT (24-28 weeks of gestation).

Results

Of 636 participants, 74 (12%) developed gestational diabetes mellitus, according to World Health Organization 2013 criteria, at 24-28 weeks of gestation. Applying WHO 2013 criteria to the early OGTT with at least one abnormal value gave a low sensitivity of 0.35 (95% confidence interval 0.24 to 0.47), high specificity of 0.96 (0.95 to 0.98), positive predictive value of 0.57 (0.41 to 0.71), negative predictive value of 0.92 (0.89 to 0.94), positive likelihood ratio of 10.46 (6.21 to 17.63), negative likelihood ratio of 0.65 (0.55 to 0.78), and diagnostic odds ratio of 15.98 (8.38 to 30.47). Lowering the postload glucose values (75 g OGTT cut-off values of 5.1, 8.9, and 7.8 mmol/L) improved the detection rate (53%, 95% confidence interval 41% to 64%) and negative predictive value (0.94, 0.91 to 0.95), but decreased the specificity (0.91, 0.88 to 0.93) and positive predictive value (0.42, 0.32 to 0.53) at a false positive rate of 9% (positive likelihood ratio 5.59, 4.0 to 7.81; negative likelihood ratio 0.64, 0.52 to 0.77; and diagnostic odds ratio 10.07, 6.26 to 18.31).

Conclusions

The results of this prospective low risk cohort study indicated that the 75 g OGTT as a screening tool in early pregnancy is not sensitive enough when applying WHO 2013 criteria. Postload glucose values were higher in early pregnancy complicated by diabetes in pregnancy. Lowering the postload cut-off values identified a high risk group for later development of gestational diabetes mellitus or those who might benefit from earlier treatment. Results from randomised controlled trials showing a beneficial effect of early intervention are unclear.

Trial registration

ClinicalTrials.gov NCT02035059.

Fetal Doppler monitoring during maternal open-heart surgery: Case report and key aspects of a multidisciplinary challenge

CASE REPORT

Herein we present the case of a 33-year nulliparous woman at 21 weeks of gestation with mitral valve vegetation resulting from infective endocarditis. Due to the mother's critical condition caused by consecutive thromboembolic events, surgery with cardiopulmonary bypass was indicated. During surgery the fetus was monitored by a specialized obstetrician who repetitively measured the Doppler indices of the umbilical artery, Ductus venosus and uterine artery. Right after CO₂ was insufflated into the operating area, the Doppler monitoring showed an increased Pulsatility Index of the Umbilical artery right before fetal distress with bradycardia occurred. A subsequent maternal arterial blood gas analysis showed an acidosis with hypercapnia. Consequently, the CO₂ insufflation was stopped and the gas flow on the Heart Lung Machine increased. After regaining homeostasis of acidosis, the Doppler Indices and fetal heart rate recovered. The remaining surgery and postoperative course were uneventful. At the 37 weeks of gestation a healthy boy was delivered by Cesarean section and at the age of two years, the neurodevelopment was assessed, which indicated normal development in mental cognition, language and motoric. This report presents a periodic Doppler examination of the maternal and fetal circulation during surgery on CPB while also discussing the possible impact of fetal monitoring in managing open cardiac surgery in pregnancy.

Work-Related Dermatoses of the Feet in Professional Dancers: A Pilot Study

OBJECTIVE

The feet of professional dancers are exposed to high work-related stresses. To date, data from the professional dance sector concerning this matter are lacking. The aim of this exploratory project was to analyze and evaluate skin health in the foot area with regard to the prevalence of dermatoses, their locations, as well as gender-specific and load-specific differences.

METHODS

Professional classical and neo-classical ballet dancers were examined at two time points: in a phase with increased stress (T0: daily training sessions, rehearsals, and high performance frequency) (n=51, 35 females, 16 males) and after a 24-day rest phase (T1: n=35, 28 females, 7 males). In addition, gender-specific and load-specific (T0 and T1) differences were evaluated.

RESULTS

All professional dancers were affected by skin lesions of the feet at T0. Hyperkeratosis (96.1%), onychomycosis (27.5%), and subungual hematoma (11.8%) were the most frequent dermatoses of the feet of professional dancers. Onychomycosis affected the nails of the big toes in particular (right 15.7%; left 13.7%), and subungual hematomas were found exclusively on the nails of the first toe (right 7.8%; left 7.8%). Women tended to be more frequently affected by hyperkeratosis, men more frequently by onychomycosis. There were no load-specific differences between the stress and rest phases.

CONCLUSION

The prevalence of work-related dermatoses is equally high among female and male dancers. The results can be used for further research and serve as a basis for specific measures of behavioral and environmental prevention in dance.

Vaginal Birth at Term - Part 1. Guideline of the DGGG, OEGGG and SGGG (S3-Level, AWMF Registry No. 015/083, December 2020)

Purpose This guideline aims to summarize the current state of knowledge about vaginal birth at term. The guideline focuses on definitions of the physiological stages of labor as well as differentiating between various pathological developments and conditions. It also assesses the need for intervention and the options to avoid interventions. This first part presents recommendations and statements about patient information and counselling, general patient care, monitoring of patients, pain management and quality control measures for vaginal birth. Methods The German recommendations largely reproduce the recommendations of the National Institute for Health and Care Excellence (NICE) CG 190 guideline "Intrapartum care for healthy women and babies". Other international guidelines were also consulted in specific cases when compiling this guideline. In addition, a systematic search and analysis of the literature was carried out using PICO questions, if this was considered necessary, and other systematic reviews and individual studies were taken into account. For easier comprehension, the assessment tools of the Scottish Intercollegiate Guidelines Network (SIGN) were used to evaluate the quality of the additionally consulted studies. Otherwise, the GRADE system was used for the NICE guideline and the evidence reports of the IQWiG were used to evaluate the quality of the evidence. Recommendations Recommendations and statements were formulated based on identified evidence and/or a structured consensus.

Vaginal Birth at Term - Part 2. Guideline of the DGGG, OEGGG and SGGG (S3-Level, AWMF Registry No. 015/083, December 2020)

Purpose This guideline aims to summarize the current state of knowledge about vaginal birth at term. The guideline focuses on definitions of the physiological stages of labor as well as differentiating between various pathological developments and conditions. It also assesses the need for intervention and the options to avoid interventions. The second part of this guideline presents recommendations and statements on care during the dilation and expulsion stages as well as during the placental/postnatal stage. Methods The German recommendations largely reproduce the recommendations of the National Institute for Health and Care Excellence (NICE) CG190 guideline "Intrapartum care for healthy women and babies". Other international guidelines were also consulted in individual cases when compiling this guideline. In addition, a systematic search and analysis of the literature was carried out using PICO questions where necessary, and other systematic reviews and individual studies were taken into account. For easier comprehension, the assessment tools of the Scottish Intercollegiate Guidelines Network (SIGN) were used to evaluate the quality of additionally consulted studies. Otherwise, the GRADE system was used for the NICE guideline, and the evidence reports of the IQWiG were used to evaluate the quality of the evidence. Recommendations Recommendations and statements were formulated based on identified evidence and/or a structured consensus.

Mortality risk is increased in chronotropic incompetent device carriers with acute heart failure

Introduction

In heart failure (HF), chronotropic incompetence is a major factor limiting cardiac output and exercise capacity. In patients carrying cardiac implantable electronic devices (CIED), accelerometer-based rate adaption (R-mode) counterbalances chronotropic incompetence during physical activity but fails to modulate heart rate under circumstances of high metabolic demand.

Purpose

We hypothesized that an activated R-mode, a surrogate of chronotropic incompetence, indicates worse prognosis during and after episodes of acutely decompensated HF (AHF).

Methods

We analysed 632 patients enrolled between 01/2014 and 02/2018 in an ongoing registry that phenotypes and follows patients admitted for AHF. We compared CIED carriers with activated R-mode (CIED-R; n=37, 16% women) with CIED carriers not in R-mode (CIED-0; n=64, 23% women) and patients without CIEDs (no-CIED; n=511, 43% women). Information on survival status was collected up to 12 months after discharge from index hospitalisation (IH). Uni- and multivariable Cox proportional hazard regression was used to identify predictors of 12-month mortality risk.

Results

Mean age of the study sample was 74 (11) years, 39% were women, median LVEF on admission was 51 (quartiles 32, 59) % and de novo HF was detected in 20% of all patients. Median length of IH was 10 (7, 14) days. In-hospital mortality was similar across groups, but 12-month mortality risk was affected by chronotropic incompetence as indicated by R-mode activation: age- and sex-associated hazard ratio (HR) for CIED-R was 2.61 (95% CI 1.59–4.29, p<0.001) compared to group no-CIED, and 2.44 (95% CI 1.25–4.74, p=0.009) compared to group CIED-0. Amongst univariable predictors of mortality risk, strong associations were found for NT-proBNP levels (p<0.001), Charlson comorbidity index (p=0.001), and de novo HF (p=0.003). These effects persisted after multivariable adjustment for comorbidity burden. Within CIED-R, mortality risk was similar in patients with pacemakers vs. ICDs (HR 1.20, 95% CI 0.49–2.95) and in subgroups with LVEF <50% vs. ≥50% (HR 1.10, 95% CI 0.79–1.53). Mean heart rate on admission was lower in CIED-R vs. CIED-0 or no-CIED (70 bpm vs. 80 bpm or 82 bpm; both p<0.001). Heart rate on admission had no impact on frequency of in-hospital worsenings or death. However, we found a 36% increase in mortality risk per tertile of heart rate at discharge (HR 1.36, 95% CI 1.10–1.69, p=0.004) after exclusion of patients with an activated R-mode.

Conclusion

In AHF, R-mode stimulation was associated with an increased 12-month mortality risk, independent of LVEF, type of CIED, burden of comorbidities and type of presentation. Further, increased resting heart rate at discharge predicted 12-month mortality risk only in patients without an activated R-mode. Our findings suggest that chronotropic incompetence per se worsens outcome in AHF and may not be adequately treated through accelerometer-based R-mode stimulation.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Comprehensive Heart Failure Centre (CHFC) Würzburg is funded by the Federal Ministry of Education and Research, Integrated Research and Treatment Centre “Prevention of Heart Failure and its Complications”.

A facile method for grafting functional hydrogel films on PTFE, PVDF, and TPX polymers

The use of polymeric materials in biomedical applications requires a judicious control of surface properties as they are directly related to cellular interactions and biocompatibility. The most desired chemical surface properties include hydrophilicity and the presence of functional groups for surface modification. In this work, we describe a method to graft a highly stable, ultra-thin, amine-functional hydrogel layer onto highly inert surfaces of poly(tetrafluoroethylene) (PTFE), poly(vinylidene fluoride) (PVDF), and poly(4-methyl-1-pentene) (PMP or TPX). Covalent grafting is realized with hydrophilic poly(vinylamine-co-acetamide)s by C-H insertion crosslinking (CHic) chemistry initiated by UV light. These polyvinylamides carry tetrafluorophenyl azide groups as photo or thermo activated binding sites and contain further free amine groups, which can be used to bind peptides such as biological ligands, polysaccharides, or other hydrogel layers. The covalently bound surface layers resist intensive Soxhlet extraction confirming the stability of the coating. Fluorescent staining verified the accessibility of free primary amine groups, which can be used for the functionalization of the surface with bioactive molecules. The coating demonstrates hydrophobic wetting behavior when conditioned in air and hydrophilic wetting behavior when conditioned in water showing the presence of loosely crosslinked polymer chains that can re-orient. We believe that the reported application of CHic for the surface modification of fluorinated polymers like PTFE and PVDF as well as TPX can form the basis for advanced biocompatible and biofunctional surface engineering.

Tuning the Elasticity of Nanogels Improves Their Circulation Time by Evading Immune Cells

Peptide receptor radionuclide therapy is used to treat solid tumors by locally delivering radiation. However, due to nephro‐ and hepato‐toxicity, it is limited by its dosage. To amplify radiation damage to tumor cells, radiolabeled nanogels can be used. We show that by tuning the mechanical properties of nanogels significant enhancement in circulation half‐life of the gel could be achieved. We demonstrate why and how small changes in the mechanical properties of the nanogels influence its cellular fate. Nanogels with a storage modulus of 37 kPa were minimally phagocytosed by monocytes and macrophages compared to nanogels with 93 kPa modulus. Using PET/CT a significant difference in the blood circulation time of the nanogels was shown. Computer simulations affirmed the results and predicted the mechanism of cellular uptake of the nanogels. Altogether, this work emphasizes the important role of elasticity even for particles that are inherently soft such as nano‐ or microgels.

Diagnosis and Therapy of Iron Deficiency Anemia During Pregnancy: Recommendation of the Austrian Society for Gynecology and Obstetrics (OEGGG)

This overview analyzes the data on the controversial therapy of iron substitution during pregnancy, the diagnosis of iron deficiency anemia and the indication-related therapy, and is the first recommendation issued by the OEGGG on the appropriate therapy. The effects of anemia during pregnancy on postnatal outcomes have been intensively investigated with heterogeneous results. A final scientific conclusion with regards to the "optimal" maternal hemoglobin level is limited by the heterogeneous results of various studies, many of which were conducted in emerging nations (with different dietary habits and structural differences in the respective healthcare systems). The current literature even suggests that there may be a connection between both decreased and increased maternal serum hemoglobin concentrations and unfavorable short-term and long-term neonatal outcomes. In Austria, 67 percent of pregnant women take pharmacological supplements or use a variety of dietary supplements. Clinically, the prevalence of maternal anemia is often overestimated, leading to overtreatment of pregnant women (iron substitution without a medical indication). To obtain a differential diagnosis, a workup of the indications for treatment should be carried out prior to initiating any form of iron substitution during pregnancy. If treatment is medically indicated, oral iron substitution is usually sufficient. Because of the restricted approval and potential side effects, medical indications for intravenous iron substitution should be limited. Intravenous iron substitution without a prior detailed diagnostic workup is an off-label use and should only be used in very limited cases, and women should be advised accordingly.

[Potassium hydroxide 5 % solution in actinic keratosis : A novel therapeutic approach in the lesion-directed treatment]

Hintergrund

Die aktinische Keratose (AK) ist ein epitheliales Carcinoma in situ der Haut. Aufgrund des Risikos einer malignen Transformation besteht ein frühzeitiger Behandlungsbedarf. Gerade die initiale Therapie sollte neben der Wirksamkeit eine gute Verträglichkeit und Anwenderfreundlichkeit aufweisen. Kaliumhydroxid (KOH)-Lösung ist als keratolytische Behandlungsoption bei hyperkeratotischen Hauterkrankungen, wie z. B. Mollusca contagiosa, bereits etabliert.

Methodik

Wirksamkeit und Verträglichkeit von KOH-5 %-Lösung zur Behandlung der leichten bis moderaten AK wurden in einer prospektiven, einarmigen, multizentrischen Medizinproduktestudie (Treatment of AK with KOH [TAKKOH]) untersucht. Die KOH-Lösung wurde 2‑mal täglich über 14 Tage aufgetragen mit anschließender Behandlungspause von 14 Tagen (≙ 1 Behandlungszyklus) für maximal 3 Behandlungszyklen oder mindestens bis zum Behandlungserfolg. Das primäre Zielkriterium „Behandlungserfolg“ wurde als komplette Remission (CR) aller AK-Läsionen eines Patienten definiert. Sekundäre Zielkriterien beinhalteten die Beurteilung der partiellen Remission (PR), der Anzahl an AK-Läsionen in Remission, die Wirksamkeitsbeurteilung anhand von Schulnoten durch Prüfärzte und Patienten sowie sicherheitsrelevante Endpunkte.

Ergebnisse

Es wurden 73 Patienten in die Studie eingeschlossen. Eine CR wurde von 54,9 % der Patienten erreicht, eine PR von 64,8 % bei einer Reduktion der Gesamtzahl an Läsionen um 69,9 %. Bei 46,6 % der Patienten wurden unerwünschte Ereignisse beobachtet. Diese überwiegend unerwünschten Wirkungen (82,6 %) stellten ausnahmslos transiente und milde lokale Hautreaktionen dar.

Schlussfolgerung

Die Studie liefert Hinweise auf die Wirksamkeit und Sicherheit von KOH-5 %-Lösung zur läsionsgerichteten topischen Therapie der AK.

Effects of temporal fine structure preservation on spatial hearing in bilateral cochlear implant users

Typically, the coding strategies of cochlear implant audio processors discard acoustic temporal fine structure information (TFS), which may be related to the poor perception of interaural time differences (ITDs) and the resulting reduced spatial hearing capabilities compared to normal-hearing individuals. This study aimed to investigate to what extent bilateral cochlear implant (BiCI) recipients can exploit ITD cues provided by a TFS preserving coding strategy (FS4) in a series of sound field spatial hearing tests. As a baseline, we assessed the sensitivity to ITDs and binaural beats of 12 BiCI subjects with a coding strategy disregarding fine structure (HDCIS) and the FS4 strategy. For 250 Hz pure-tone stimuli but not for broadband noise, the BiCI users had significantly improved ITD discrimination using the FS4 strategy. In the binaural beat detection task and the broadband sound localization, spatial discrimination, and tracking tasks, no significant differences between the two tested coding strategies were observed. These results suggest that ITD sensitivity did not generalize to broadband stimuli or sound field spatial hearing tests, suggesting that it would not be useful for real-world listening.

Enzyme mimetic microgel coating for endogenous nitric oxide mediated inhibition of platelet activation

Nitric oxide (NO) continuously generated by healthy endothelium prevents platelet activation and maintains vascular homeostasis. However, when artificial surfaces, like of extracorporeal membrane oxygenator comes in contact with blood, protein adsorption and thereby platelet activation takes place, which eventually leads to thrombus formation. To overcome this, we present an antifouling microgel coating mimicking the function of enzyme glutathione peroxidase to endogenously generate NO in the blood plasma from endogenous NO-donors and maintain a physiological NO flux. Microgels are synthesized by copolymerization of highly hydrophilic N-(2-hydroxypropyl)methacrylamide (HPMA) and glycidyl methacrylate (GMA) with diselenide crosslinks. For immobilization of the microgels on hydrophobic poly(4-methylpentene) (TPX) membranes bioengineered amphiphilic anchor peptides with free thiols are used. The anchor peptide attaches to the TPX membranes by hydrophobic interactions while the free thiols are presented for crosslinking with the microgels. The hydrophilic nature of the microgel coating prevents protein adsorption while the reversible diselenide bridges make the microgels responsive to the reducing environment and lead to the formation of reactive selenols/selenolates. The generated selenols/selenolates provide an efficient and sustained NO-release from endogenous S-nitrosothiols (RSNOs) mimicking the enzymatic function of glutathione peroxidase. On exposure to the whole blood, the microgel coating inhibited platelet activation and prolonged the blood clotting time.

Cellular events of acute, resolving or progressive COVID-19 in SARS-CoV-2 infected non-human primates

Understanding SARS-CoV-2 associated immune pathology is crucial to develop pan-effective vaccines and treatments. Here we investigate the immune events from the acute state up to four weeks post SARS-CoV-2 infection, in non-human primates (NHP) with heterogeneous pulmonary pathology. We show a robust migration of CD16 expressing monocytes to the lungs occurring during the acute phase, and we describe two subsets of interstitial macrophages (HLA-DR+CD206-): a transitional CD11c+CD16+ cell population directly associated with IL-6 levels in plasma, and a long-lasting CD11b+CD16+ cell population. Trafficking of monocytes is mediated by TARC (CCL17) and associates with viral load measured in bronchial brushes. We also describe associations between disease outcomes and high levels of cell infiltration in lungs including CD11b+CD16hi macrophages and CD11b+ neutrophils. Accumulation of macrophages is long-lasting and detectable even in animals with mild or no signs of disease. Interestingly, animals with anti-inflammatory responses including high IL-10:IL-6 and kynurenine to tryptophan ratios show less severe illness. Our results unravel cellular mechanisms of COVID-19 and suggest that NHP may be appropriate models to test immune therapies.

Atrial fibrillation impairs ventricular function by altering excitation-contraction coupling in the human heart

 

Atrial fibrillation (AF) often co-exists in patients with heart failure (HF). Recent clinical evidence suggests that the arrhythmic component of AF alone may contribute to ventricular dysfunction. However, the pathophysiological effects of a non-tachycardic AF on the human ventricle are unknown. To investigate the effects of normofrequent AF on the human ventricle we investigated ventricular myocardium from patients with preserved ejection fraction with sinus rhythm (SR) or AF in the absence of HF (compensated hypertrophy, EF>50%, matched clinical characteristics). In histological analysis we detected no difference between SR (n=9) vs. AF (n=6) regarding the amount and distribution of fibrosis. For functional investigation, Ca-handling was studied (Fura-2 AM). While systolic Ca-transient amplitude was in trend reduced in isolated human ventricular AF cardiomyocytes, we found a significantly prolonged Ca-elimination time (n=17–22 cells/4 pat.). Using caffeine application, a decreased SR Ca-load in AF was detected, which may be explained by a significant decrease in SERCA2a activity (ksys-kCaff, n=10–12/4 pat.). Patch-clamp experiments revealed a prolonged action potential duration in AF cardiomyocytes (n=5/15 cells).

For the standardized evaluation of the mechanisms of persistent normofrequent arrhythmia, we simulated AF in vitro by using arrhythmic (1 Hz, 40% R-R-variability) or rhythmic (1 Hz) field stimulation. We performed contractility experiments using in-toto isolated human ventricular trabeculae from explanted human hearts. After 8h of pacing, arrhythmically stimulated human trabeculae showed a significantly reduced systolic force, an increase in diastolic tension and a prolonged relaxation (n=11–12 trabeculae/11 pat.). For studying the cellular effects of persistent normofrequent arrhythmia in a model suitable for chronic pacing (up to 7 days), we utilized human iPSC cardiomyocytes (iPSC-CM) from healthy donors (n=6). After 7 days, arrhythmic paced iPSC-CM showed a significantly reduced systolic Ca-transient amplitude, a prolonged Ca-elimination time (n=35/45 cells) as well as a reduced SR Ca-load and a trend towards a lower SERCA2a activity compared to control (n=11 cells). Confocal line-scans (Fluo-4 AM) showed an increased diastolic SR Ca-release, which might also explain the reduced SR Ca-content (n=45/35 cells). Moreover, in irregularly paced iPSC-CM we found significant increased levels of cytosolic Na (n=69 cells each) and in patch-clamp experiments a significantly prolonged action potential duration (n=14/11 cells/3 diff.).

This study demonstrates that a normofrequent arrhythmic ventricular excitation as it occurs in AF impairs human ventricular myocardial function by altering cardiomyocyte excitation-contraction coupling. Thus, this study provides the first translational mechanistic characterization and the potential negative impact of isolated AF in the absence of tachycardia on the human ventricle.

Funding Acknowledgement

Type of funding source: None

Die Klinik und Poliklinik für Dermatologie und Venerologie der Universitätsmedizin Rostock – von Fischschuppenerkrankungen, Mondscheinkindern und viel, viel Mee(h)r!

Die Universität Rostock und die Universitätsmedizin als Gründungsfakultät ist die drittälteste Alma Mater in Mitteleuropa – 2019 hat sie ihr 600-jähriges Bestehen gefeiert. Die Klinik und Poliklinik für Dermatologie und Venerologie der Universitätsmedizin Rostock kann auf eine ähnlich lange Tradition zurückblicken – sie ist das drittälteste Ordinariat nach Breslau und der Charité in Berlin. Gemäß dem universitären Motto „Traditio et Innovatio“ hat sich aus dieser Tradition, begründet durch angesehene Ordinarien wie Wolters, Frieboes oder auch Flegel zu DDR-Zeiten, in den letzten 4 Jahren eine moderne universitäre Dermatologische Universitätsklinik (DUK) mit hoher Entwicklungsdynamik und einem Masterplan DUK2030 für alle Bereiche der Krankenversorgung, Forschung und Lehre entwickelt. Unter einem Dach sind stationäre, teilstationäre, ambulante und operative Patientenversorgung zusammen mit dem histologischen und klinischen Labor und den Forschungslaboren vereint. Unter anderem durch Zentrumsgründungen vor Ort (Hautkrebszentrum, Immuntherapiezentrum, Allergologisches Zentrum, Gefäß- und Wundzentrum, Zentrum für Seltene (Haut-) Erkrankungen) und auf europäischer Ebene (Europäisches Referenznetzwerkzentrum für seltene Hauterkrankungen) hat diese interdisziplinäre Zusammenarbeit die Klinik lokal und überregional sehr gut vernetzt. Ein junges, hochengagiertes und noch expandierendes Team hat diese bisherige Entwicklung ermöglicht. Dafür kann allen Beteiligten nicht genug gedankt werden. Dieser und die folgenden Artikel geben einen Einblick in die dermatologische Welt der Universitätsmedizin Rostock.

Experimentelle Forschung an der Klinik und Poliklinik für Dermatologie und Venerologie

Seit Antritt von Prof. Dr. med. Steffen Emmert als Ordinarius der Klinik und Poliklinik für Dermatologie und Venerologie im Jahr 2015 konnte das dermatologische Forschungslabor sukzessive aufgebaut und erweitert werden. Im Einklang mit dem onkologischen Schwerpunkt der Universitätsmedizin Rostock sowie dem von der Landesregierung forcierten „Gesundheitsland Mecklenburg-Vorpommern“ wird grundlagenorientierten und translationalen Projekten nachgegangen. Das vorwiegend drittmittelfinanzierte und stetig wachsende Forschungsteam bearbeitet diverse Fragestellungen in den Bereichen der Dermato-Onkologie, Plasmamedizin und seltenen Hauterkrankungen. Inzwischen auf einem soliden Fundament stehend, befindet sich der Forschungsbereich weiterhin in einem dynamischen Entwicklungsprozess. Nicht nur personell, sondern auch thematisch und methodisch wird er derzeit durch die Integration weiterer Arbeitsgruppen unter der Leitung von Ärzten aus der Klinik ergänzt und ausgebaut. Diverse Kollaborationen an der Universitätsmedizin Rostock und im Land zeugen von einem freundlichen, unterstützenden und kollegialen Umfeld, das die Integration am Standort befördert hat.

Poly(vinylamine-co-N-isopropylacrylamide) linear polymer and hydrogels with tuned thermoresponsivity

The fabrication of functional hydrogels with tuned thermoresponsivity is a major challenge. To meet this challenge we copolymerize N-isopropylacrylamide (NIPAm) with N-vinylformamide (NVF) in different ratios with the formamide group being subsequently selectively hydrolyzed to the corresponding amine (VAm). The copolymers are crosslinked with phenylcarbonate telechelic glycol. The influence of the NIPAm : VAm ratio on the thermoresponsitiviy is investigated in terms of absorbance, rheology, NMR spectroscopy, relaxometry, and diffusometry. Phase transition temperatures, change in the entropy of the polymer-water system, and width of the transition in the process of coil-to-globule and swollen-to-collapsed network transitions were evaluated by a two state model and Boltzmann sigmoidal function.

[Current indications for plasma therapy in dermatology]

BACKGROUND

Plasma medicine is gaining increasing interest and provides a multitude of dermatological applications. Cold atmospheric pressure plasma (CAP) can be used in clinical applications without harming the treated tissue or in a tissue destructive manner. It consists of a complex mixture of biologically active agents, which can act synergistically on the treated material or tissue.

OBJECTIVES

A summary of the current research findings regarding dermatological applications of CAP is provided.

METHODS

Literature on CAP applications in dermatology has been screened and summarized.

RESULTS

CAP exerts antimicrobial, tissue-stimulating, blood-flow-stimulating but also pro-apoptotic effects. By exploiting these properties, CAP is successfully applied for disinfection and treatment of chronic ulcerations. Furthermore, positive effects of CAP have been shown for the treatment of tumors, actinic keratosis, scars, ichthyosis, atopic eczema as well as for alleviation of pain and itch.

CONCLUSIONS

While the use of CAP for disinfection and wound treatment has already moved into clinical practice, further applications such as cancer treatment are still exploratory.

Physical gels of poly(vinylamine) by thermal curing

Physical gels are a versatile class of materials which can find application in sensors, electrochemistry, biomedicine or rheological modifiers. Herein, we present a hydrogen-bonded physical gel which is based on the interaction between phenylcarbonate telechelic poly(ethylene glycol) (PEG-PC) and poly(vinyl amine-co-acetamide) (p(VAm-co-VAA)). The critical gelation concentration was found to be 10 wt% by rheology and NMR. UV-vis spectroscopy and dynamic light scattering reveal the formation of aggregates in the gel. Rheology and differential scanning calorimetry (DSC) was used to show the effect of thermal curing on the mechanical properties of the physical gel.

Repeated heating cooling cycles can anneal inhomogeneity in physical gels and significantly improve their mechanical properties.

P5259Evaluation of functional impairment and cardiac remodelling in isolated left branch bundle block using magnetic resonance imaging

Introduction

Left bundle-branch block (LBBB) is associated with underlying cardiovascular abnormalities, such as dilated cardiomyopathy and coronary heart disease. However, an isolated LBBB can be found in individuals without detectable cardiovascular disease. Echocardiographic studies demonstrated a reduced left ventricular (LV) ejection fraction (EF) and an increased LV cavity volume and mass in patients with isolated LBBB. Recent studies have shown larger cavity volumes (end-diastolic volume – EDV; end-systolic volume – ESV) and lower LVEF using CMR. However, there is still limited data on cardiac function, volumes and mass and the correlation between the parameters and the QRS duration (QRS) in patients with isolated LBBB.

Purpose

In this retrospective study LV function, volume, mass, T1-values and myocardial strain were measured and correlation between QRS duration in patients with isolated LBBB was identified using CMR.

Methods

Potential cases were identified from our local database, who underwent CMR during 2015–2018. We excluded patients with echocardiographic abnormalities besides abnormal septal motion or greater than a mild valve disease, known cardiovascular disease (coronary artery disease, cardiomyopathy or arrhythmia), history of potential cardiotoxic chemotherapy. We could identify 26 adults, who underwent CMR in a 1.5- or 3-Tesla scanner. LBBB was confirmed by ECG prior to CMR by a cardiologist. T1-values (MOLLI) were available in 19 patients. Myocardial strain (tissue tracking) could be performed in 23 patients. Associations were tested using Pearson's correlation analysis.

Results

26 patients (age 61.5±9.6 years, 19 women, BMI 25.4 (18.2–38.1)) with isolated LBBB were included (QRS duration: 138±12ms). CMR results in the cohort revealed a reduced LVEF (53.4±3,8%) and slightly enlarged LV cavity when corrected to body-surface area (BSA) (LV-EDV/BSA: 83.7±13.8ml/m2; LV-ESV/BSA: 39.3±8.6ml/m2), when compared to normal values from the study center. There is a negative correlation between LVEF and QRS duration (r=−0.550, p<0.05) and a positive correlation between QRS duration and LV-EDV/BSA (r=0.627, p<0.05) as well as between QRS and LV-ESV/BSA (r=0.661, p<0.05). In addition, there is a positive correlation between QRS duration and myocardial mass (r=0.645, p<0.05), septal myocardial thickness (r=0.405, p<0.05) and lateral wall thickness (r=0.495, p<0.05). In addition, there is a positive correlation between LV longitudinal strain and QRS (r=0.449, p<0.05). T1-values were in normal range. There is no correlation between QRS and T1-values.

Conclusion

Using CMR a negative correlation between LV function and QRS duration and the positive correlation between LV volumes and QRS duration in patients with isolated LBBB could be identified. The absence of significant myocardial fibrosis with normal T1-values indicates an electromechanical dissociation rather than an underlying myocardial abnormality as an explanation for the reduced LVEF.

P3829Antiarrhythmic effects of Sacubitrilat (LBQ657) on Ca2+ homeostasis in ventricular cardiomyocytes

Background and objectives

Simultaneous inhibition of neprilysin and angiotensin II receptors by sacubitril/valsartan was shown to significantly reduce morbidity and mortality in heart failure patients compared to sole interference with the renin angiotensin system. Beneficial effects of increased levels of natriuretic peptides following neprilysin inhibition have been suggested, whereas direct effects of sacubitrilat on myocardial Ca2+ cycling properties remain elusive.

Methods and results

Under basal conditions the combination of active neprilysin-inhibitior sacubitrilat (LBQ657) and angiotensin II receptor inhibitor valsartan did not influence diastolic Ca2+ spark frequency (CaSpF) nor arrhythmogenic SR Ca2+ leak in murine ventricular cardiomyocytes (confocal microscopy, n CMs/hearts=80/7 vs. 100/7, P=0.91/0.99). In contrast, sacubitrilat/valsartan treatment significanty reduced CaSpF by 35±9% and SR Ca2+ leak by 45±9% in CMs that had been put under catecholaminergic stress (isoproterenol 10nM, n=81/7 vs. 62/7, P<0.001 both). This effect could be clearly be attributed to the neprilysin inhibitor sacubitrilat as sole sacubitrilat treatment also reduced both parameters by similar degrees (reduction of CaSpF by 57±7% and SR Ca2+ leak by 76±5%; n=101/4 vs. 108/4, P<0.01 both) whereas sole valsartan treatment did not affect diastolic SR Ca2+ leak. Of note, systolic Ca2+ release, SR Ca2+ load and Ca2+ transient kinetics of murine CMs were not compromised upon treatment with sacubitrilat (epifluorescence microscopy, n=41/6 vs. 39/6). Importantly, sacubitrilat/valsartan in combination as well as sacubitrilat alone also reduced diastolic CaSpF and SR Ca2+ leak by 40–74% in human left-ventricular CMs from patients with end-stage heart failure (n=71/8 vs. 78/8, P<0.05).

Conclusion

This study demonstrates that neprilysin-inhibition directly exerts beneficial effects on Ca2+ homeostasis in human heart failure. We can show for the first time that neprilysin-inhibition by sacubitrilat yields a strong reduction of arrhythmogenic SR Ca2+ leak without affecting systolic Ca2+ release. These effects might contribute to the mortality benefit of sacubitril/valsartan treatment in the PARADIGM Study.

Acknowledgement/Funding

THF was funded by the Deutsche Forschungsgemeinschaft (DFG) through the SFB 1002 (A11). SS is supported by the Marga und Walter Boll-Stiftung.

Abstract P6-18-08: Everolimus + exemestane for HR+ advanced breast cancer in routine clinical practice- Final results from the non-interventional trial, BRAWO

Background: In the pivotal BOLERO-2 trial, everolimus (EVE) + exemestane (EXE) more than doubled the median progression-free survival (PFS) vs EXE alone in hormone receptor positive (HR+), human epidermal growth factor-receptor 2-negative (HER2-) advanced breast cancer (ABC) recurring/progressing on/after prior non-steroidal aromatase inhibitors (NSAIs). BRAWO is a German non-interventional study conducted in patients (pts) with HR+, HER2–ABC receiving EVE + EXE, according to Summary of Product Characteristics (SmPC), in routine clinical practice. Here we report the final PFS and safety results.

Methods: This multicenter study documented 2100 pts between October 2012 and December 2017 across 341 sites in Germany. Postmenopausal women with HR+, HER2– ABC with recurrence or progression after a NSAI were included. Primary observation parameters included the evaluation of the effectiveness of EVE + EXE used in routine care for the entire pt group.

Results: In the final analysis, out of the 2100 documented pts, 2074 were included in the full analysis set. The median time since the primary diagnosis was 7.1 years and the median time from first sign of relapse (local recurrence or distant metastases) was 2.1 years. At baseline, 54.1% of pts presented with visceral metastases and 50.1% had an ECOG performance status of 0. Approximately, 63% of pts started with EVE 10 mg (median duration of exposure: 5.1 months; 95% CI, 4.6-5.4), while 34.1% started with EVE 5 mg (median duration of exposure: 4.6 months; 95% CI, 4.1-5.2).

The distribution of treatment lines was as follows: first line, 28.7% (n=595); second line, 31.9% (n=662); third line, 18.1% (n=376); fourth line, 10.7% (n=221) and, fifth line and later, 10.6% (n=220). Treatment was discontinued by 55.7% of pts (n=1170) due to progressive disease and 26% of pts (n=546) due to adverse events. The Kaplan-Meier estimate of the median PFS was 6.6 months (95% CI, 6.2-7.0). The best overall responses, based on clinical routine, were complete response, 0.8% (n=17), partial response, 7.4% (n=150), and stable disease, 41.3% (n=842). The general safety profile was consistent with the previously reported safety findings. The most common adverse events were stomatitis (any grade: 42.6%, grade 3: 3.8%, grade 4: &lt;0.1%) and fatigue (any grade: 19.8%, grade 3: 1.5%).

Conclusions: Data from BRAWO support EVE + EXE as a suitable treatment option with a reasonable safety profile for HR+, HER2− ABC recurring or progressing on/after prior NSAIs.

Citation Format: Lüftner D, Schuetz F, Schneeweiss A, Grischke E-M, Bloch W, Decker T, Uleer C, Salat C, Förster F, Schmidt M, Mundhenke C, Tesch H, Jackisch C, Fischer T, Guderian G, Hanson S, Fasching P. Everolimus + exemestane for HR+ advanced breast cancer in routine clinical practice- Final results from the non-interventional trial, BRAWO [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-08.

Statement by the OEGGG with Review of the Literature on the Mode of Delivery of Premature Infants at the Limit of Viability

In 2017, the Austrian Society for Paediatric and Adolescent Medicine (ÖGKJ) published a guideline on the primary care of premature infants at the limit of viability. In this guideline, it is recommended that a Caesarean section be preferred as mode of delivery with regard to an early preterm birth (22 + 0 – 24 + 6 weeks of pregnancy) due to an allegedly lower perinatal risk of cerebral haemorrhage. In contrast to this, the Austrian Society for Gynaecology and Obstetrics (OEGGG) considers there to be no clinical and scientific basis for this recommendation and the mode of delivery in the case of early preterm birth must be adapted to the individual maternal and foetal clinical situation. The international data available from the generally retrospective investigations show heterogeneous results regarding the mode of delivery. The prospective and randomised data in this regard are insufficient. A Cochrane analysis does not show any advantage in favour of a Caesarean delivery. The German-language guidelines (AWMF and Switzerland) make analogous recommendations for adapting the mode of delivery with regard to an early preterm birth individually to the respective clinical situation. In the case of an early preterm birth and a singleton in cephalic presentation, the OEGGG therefore recommends individual management of the delivery which takes the maternal and foetal clinical situation into account and also includes vaginal delivery as a mode of delivery in the clinical decision process.

Dynamic changes of circulating miRNAs induced by the Ebola virus vaccine VSV-EBOV

VSV-EBOV is a replication-competent Ebola virus (EBOV) vaccine, which was tested in clinical trials as response to the Ebola virus disease (EVD) outbreak 2013-2016. It is the most advanced EBOV candidate currently in the licensure process. The experimental vaccine was again administered as response to outbreaks in the Democratic Republic of Congo. However, underlying molecular mechanisms that convey protection remain incompletely understood. MicroRNAs (miRNAs) are known key regulators that influence gene expression on a post-transcriptional level. The miRNA-mediated control has emerged as a critical regulatory principle in the immune system, which strongly influences the balance of innate and adaptive immune responses by modulation of signaling pathways critical for differentiation of immune cells. We investigated expression levels of circulating miRNAs (c-miRNAs) in plasma from healthy vaccinees, as they may reflect cellular dynamics following VSV-EBOV immunization and additionally may serve as potential biomarkers for vaccine efficacy. As part of the WHO-led VEBCON consortium, we investigated safety and immunogenicity of VSV-EBOV in a phase I trial. A comprehensive analysis of expression levels on c-miRNAs from plasma samples following VSV-EBOV immunization (day 0, 1, 3 post vaccination) was conducted using RT-qPCR assays. Potential biological relevance was assessed using in silico analyses. Additionally, we correlated dynamics of miRNA expressions with our previously reported data on vaccine-induced antibody and cytokine responses and finally evaluated the prognostic power by generating ROC curves. We identified four promising miRNAs (hsa-miR-146a, hsa-miR-126, hsa-miR-199a, hsa-miR-484), showing a strong association with adaptive immune responses, exhibited favourable prognostic performance and are implicated in immunology-related functions. Our results provide evidence that miRNAs may serve as useful biomarkers for prediction of vaccine-induced immunogenicity. Furthermore, our unique data set provides insight into molecular mechanisms that underlie VSV-EBOV-mediated protective immune responses, which may help to decipher VSV-EBOV immune signature and accelerate strategic vaccine design or personalized approaches.

Intraoperative Electron Radiotherapy (IOERT) in the Treatment of Primary Breast Cancer

IOERT (intraoperative electron radiotherapy) in breast cancer is used either as a boost (10-12 Gy) followed by whole breast irradiation (WBI) or as full-dose partial breast irradiation (PBI, 20-24 Gy) during breast-conserving surgery. IOERT has the longest evidence of all IORT techniques. When administered as a boost, excellent low local recurrence rates were observed in long-term follow-up >5 years. Even in high-risk groups like triple-negative or locally advanced breast cancers, IOERT contributes to long-term local control rates of more than 90%. For selected low-risk groups, IOERT as PBI with 21 Gy seems to be a viable treatment alternative to standard WBI. IOERT has been shown to be advantageous for several reasons: Geographic misses are avoided due to direct visualization of the tumor bed; thus, a high single dose is delivered with utmost precision to small volumes, completely sparing the skin and ensuring good long-term cosmetic outcome. Furthermore, high single doses seem to induce biological mechanisms with verifiable antitumor capability in in-vitro cell-line studies. In addition, IOERT markedly shortens the overall treatment time both in combination with (now mostly hypofractionated) WBI or as a PBI in selected low-risk constellations.

Oxygenation and Lung Morphology in a Rabbit Pediatric ARDS- Model under High Peak Pressure Ventilation plus Nitric Oxide and Surfactant Compared with Veno-venous ECMO

The aim of the study is to investigate which of two treatment options of saline lavage induced ARDS in rabbits is better in terms of oxygenation and prevention of barotrauma: combined high peak pressure ventilation with surfactant administration and inhaled nitric oxide or veno-venous ECMO combined with low peak inspiratory pressure ventilation.

Materials and Methods

After saline lavage (10 cc/kg repeated as long as foamy retrieval was observed) two combined therapeutic strategies were examined: ventilation with high inspiratory pressures (35 cm H2O) with additional exogenous surfactant administration (100 mg/kg) and inhaled nitric oxide (10 PPM) (n=5, group 1) and low inspiratory pressure (20 cm H2O) ventilation under veno-venous ECMO support (n=5, group 2). The FiO2 was maintained at 1.0 in both groups. The paO2/FiO2 ratio was calculated in 30 minute intervals for 4 hours. After that the animals were sacrificed and the lungs examined macro- and microscopically. Aeration was described in a semiquantitative method using the alveolar expansion index. Oxygenation in group 1 was significantly better than in group 2, it increased significantly after surfactant but not after additional nitric oxide administration. However, the lungs in group 1 showed severe signs of baro/ergotrauma (Hyaline membranes, air leaks, infiltration of polymorphonuclear (PMN) granulocytes and macrophages, break down of alveolar capillary membranes) after 4 hrs of combined therapy, whereas the lungs in group 2 appeared normal. Adding surfactant and NO to a high tidal volume ventilation improved oxygenation, but did not prevent baro/ergotrauma. Ventilation with low inspiratory pressures combined with ECMO caused little baro/ergotrauma but adequate oxygenation could not be achieved, probably due to anatomical features of the rabbit which do not allow appropriate blood flow within the ECMO-circuit.

Die Kinetik von rezeptorvermittelter Radiotoxizität des 16α-[125I]-Iodöstradiol-3,17ß

Ziel: Es wurden radiozytotoxische Effekte von 16α-[125l]-lodöstradi- ol-3,17ß ü 125 I]E) an MCF-7-Mammakarzinom-Zellen in Abhängigkeit von der Inkubationszeit in dem Zeitraum zwischen 1 und 24 h untersucht. Methoden: Der Rezeptorstatus der Zellen wurde durch immunhisto- chemische Färbung bestimmt. Die Akkumulation von [125|]E wurde in Gegenwart und Abwesenheit von nichtradioaktivem Östradiol sowie [127I]E und in Östrogenrezeptor (ER)-negativen im Vergleich zu ER-positiven Zellen getestet. Die Ermittlung der subzellulären Verteilung erfolgte in 0,25 M Saccharose durch Ultrazentrifugation. Die Radiozytotoxizität wurde unter den verschiedenen Versuchsbedingungen durch Standard- Kolonie-Assays nach Inkubation mit [125I]E (1.85 kBq/ml-55.5 kBq/ml) für 1, 2, 4, 8, 12 und 24 h ermittelt. Ergebnisse: Eine deutliche Zytotoxizität wurde nur bei Inkubation ER-positiver Zellen mit [125I]E gefunden. Das Maximum lag bei einer Reduktion der Überlebensfraktion auf 20-25% bei Radioaktivitätskonzentrationen im Inkubationsmedium von >37 kBq/ml. Diese maximalen Effekte wurden nach Inkubationszeiten von 8 h gefunden. Eine Verlängerung der Inkubationszeit führte zu keiner weiteren Verstärkung der Toxizität. Schlußfolgerungen: Die Ergebnisse zeigen, daß die Radioaktivität an die Östrogenrezeptoren gebunden wurde. Infolge ihrer Kernlokalisation haben Radioöstrogene, die sehr niederenergetische Elektronen (Auger-Elektronen) emittieren, therapeutische Relevanz durch ER-vermittelte Entfaltung zellinaktivierender, ionisierender Strahlung ohne Beeinflussung benachbarter Zellen. Allerdings sollte anstelle von 125l das kürzerlebige 123l zur Markierung zum Einsatz kommen, da die entscheidenden Strahleneffekte innerhalb von 8 h erfolgen.

Zusammenhänge zwischen Eigenschaften von 131I-Therapiekapseln und der Radioiodkinetik

Ziel: Es sollte das Auftreten nichtreproduzierbarer Meßwerte bei Radioiodtest und Radioiodkinetik unter 131l-Therapie geklärt werden. Methoden: Der lodgehalt der Kapseln wurde kolonmetrisch und mit der Aktivierungsanalyse bestimmt. Die Messung der radiochemischen Reinheit erfolgte mittels HPLC und Elektrophorese. Das Löseverhalten der Kapseln wurde unter unterschiedlichen Bedingungen überprüft. Ergebnisse: Der lodgehalt der Kapseln schwankte zwischen 0,8 und ca. 100 μg/Kapsel. Die radiochemische Reinheit der Kapseln differierte ebenfalls (75%-99,5%). Hauptverunreinigung war lodat. Das Löseverhalten war ebenfalls unterschiedlich. Schlußfolgerung: Zusätzliches nichtradioaktives lod in den Therapiekapseln könnte eine Ursache verminderter Radioiodaufnahme unter Therapie sein.