Proof of concept of an accelerometer as a trigger for unilateral diaphragmatic pacing: a porcine model.

BACKGROUND: Unilateral diaphragmatic paralysis in patients with univentricular heart is a known complication after pediatric cardiac surgery. Because diaphragmatic excursion has a significant influence on perfusion of the pulmonary arteries and hemodynamics in these patients, unilateral loss of function leads to multiple complications. The current treatment of choice, diaphragmatic plication, does not lead to a full return of function. A unilateral diaphragmatic pacemaker has shown potential as a new treatment option. In this study, we investigated an accelerometer as a trigger for a unilateral diaphragm pacemaker (closed-loop system). METHODS: Seven pigs (mean weight 20.7 ± 2.25 kg) each were implanted with a customized accelerometer on the right diaphragmatic dome. Accelerometer recordings (mV) of the diaphragmatic excursion of the right diaphragm were compared with findings using established methods (fluoroscopy [mm]; ultrasound, M-mode [cm]). For detection of the amplitude of diaphragmatic excursions, the diaphragm was stimulated with increasing amperage by a cuff electrode implanted around the right phrenic nerve. RESULTS: Results with the different techniques for measuring diaphragmatic excursions showed correlations between accelerometer and fluoroscopy values (correlation coefficient 0.800, P < 0.001), accelerometer and ultrasound values (0.883, P < 0.001), and fluoroscopy and ultrasound values (0.816, P < 0.001). CONCLUSION: The accelerometer is a valid method for detecting diaphragmatic excursion and can be used as a trigger for a unilateral diaphragmatic pacemaker.

A Re-evaluation of Online Pornography Use in Germany: A Combination of Web Tracking and Survey Data Analysis.

Several researchers have questioned the reliability of pornography research's findings. Following a recent call to use more reliable data sources, we conducted two analyses to investigate patterns and predictors of online pornography use (OPU). Our analyses were based on data from a large-scale German online web tracking panel (N = 3018) gathered from June 2018 to June 2019. The study we present here has two parts: In the first part, we looked at group differences (gender and age) in tracked OPU. Overall, this part's results confirm questionnaire-based research findings regarding sex and age differences. In the second part of our study, we combined the web tracking data with data from an online survey which was answered by a subset of the tracking participants (n = 1315) to assess the relevance of various predictors of OPU that have been identified in previous research. Again, our results mostly echoed previous findings based on self-reports. Online pornography was used more by males and younger individuals, while relationship status, sexist attitudes, and social dominance orientation were not associated with OPU. However, we did find differences in OPU between members of different religious communities. Our study confirms some critical findings on OPU from previous questionnaire-based research while extending existing research by providing a more fine-grained analysis of usage patterns based on web tracking data.

[Assessment and operationalization of the characteristic "gender" in representative population-based surveys: challenges and implications with the example of the GeSiD study]. / Erfassung und Operationalisierung des Merkmals "Geschlecht" in repräsentativen Bevölkerungsstichproben: Herausforderungen und Implikationen am Beispiel der GeSiD-Studie.

Representative quantitative surveys assess the participants' gender in order to allow for gender specific analyses of the research questions and to draw conclusions about the populations. This is important in order to develop information and interventions tailored to the target groups. However, although gender is no longer considered exclusively as a binary construct, it is still often surveyed through a binary variable with the response options woman/man or female/male. In this article, we discuss why this approach is outdated or incomplete and why a move away from this approach is important and necessary. Using the GeSiD study on "Health and Sexuality in Germany" as an example, in this discussion post we demonstrate how gender can be assessed by means of a two-step model in which the first step assesses gender assigned at birth and the second step the subjective gender affiliation. At the same time, we discuss the challenges that this approach brings along. We place the results of the GeSiD study into a larger context and discuss the implications and possibilities for operationalizing gender in representative surveys.

[Therapy and Outcome of Neonates with Congenital Diaphragmatic Hernia and Congenital Heart Defects]. / Therapie und Outcome von Neugeborenen mit kongenitaler Zwerchfellhernie und angeborenen Herzfehlern.

Die Mortalität von Patienten mit isoliert auftretenden angeborenen Zwerchfellhernien liegt in spezialisierten Zentren bei 20-40%. Wesentliche, das Outcome beeinflussende Faktoren, sind die bestehende Lungenhypoplasie, eine daraus resultierende pulmonale Hypertonie, sowie das Vorliegen weiterer Fehlbildungen. Begleitfehlbildungen wie angeborene Herzfehler treten bei ca. 18% aller Neonaten mit Zwerchfellhernie auf. Schwere angeborene Herzfehler wie das hypoplastische Linksherz Syndrom zeigen sich in ca. 8% der Fälle. In einer retrospektiven Analyse des Patientenkollektivs unserer Klinik zwischen 01/2012 und 12/2018 wurde das prä- und postnatale Management, sowie das Outcome von Neugeborenen mit der Kombination aus angeborenen Herzfehlern und Zwerchfellhernien untersucht. Im Studienzeitraum wurden in unserer Klinik 156 Neugeborene mit Zwerchfellhernie behandelt. Bei 10 Patienten (6,4%) lag zusätzlich ein schwerer, bei 11 Patienten (7,1%) ein moderater Herzfehler vor. 6/21 Patienten verstarben im Verlauf des Krankenhausaufenthaltes, davon 3 am ersten Lebenstag. Es zeigte sich eine deutlich geringere Mortalität bei Patienten mit Zwerchfellhernie und moderatem Herzfehler im Vergleich zu schwerem Herzfehler (9 vs. 50%). Besonders hoch lag die Mortalität bei Kindern mit einem univentrikulären Herzen. Trotz einer deutlich reduzierten Prognose bei der Kombination aus angeborenem Herzfehler und Zwerchfellhernie muss nicht generell mit einer infausten Prognose gerechnet werden. In spezialisierten Zentren kann ein kurativer Ansatz erfolgen.The mortality of patients with isolated congenital diaphragmatic hernia (CDH) in specialized centers is 20-40%. The main factors influencing the outcome are the underlying pulmonary hypoplasia, the resulting pulmonary hypertension and the presence of other malformations. Concomitant malformations such as congenital heart defects occur in around 18% of all neonates with a diaphragmatic hernia. Serious congenital heart defects such as hypoplastic left heart syndrome occur in approximately 8% of cases. In a retrospective analysis of the patient collective of our hospital between 01/2012 and 12/2018, the prenatal and postnatal management as well as the outcome of newborns with a combination of congenital heart defects and diaphragmatic hernias were examined. During the study period, 156 newborns with diaphragmatic hernias were treated at our institution. In 10 patients (6.4%) there was also a severe, and in 11 patients (7.1%) a moderate heart defect. 6/21 patients died during their hospital stay, 3 of them on the first day of life. There was a significantly lower mortality in patients with diaphragmatic hernia and moderate heart defects compared to severe heart defects (9 vs. 50%). The mortality in children with a univentricular heart was particularly high. Despite a significantly reduced prognosis for the combination of congenital heart defects and diaphragmatic hernia, generally a poor prognosis does not have to be expected. A curative approach can be achieved in specialized centers.

Prenatal Diagnosis and Postnatal Outcome of Fetuses with Pulmonary Atresia and Ventricular Septal Defect.

PURPOSE: To assess the intrauterine course, associated conditions and postnatal outcome of fetuses with pulmonary atresia with ventricular septal defect (PAVSD). METHODS: All cases of PAVSD diagnosed prenatally over a period of 10 years with a minimum follow-up of 6.5 years were retrospectively collected in 3 tertiary referral centers. RESULTS: 50 cases of PAVSD were diagnosed prenatally. 44.0 % of fetuses had isolated PAVSD, 4.0 % had associated cardiac anomalies, 10.0 % had extra-cardiac anomalies, 38.0 % had chromosomal anomalies, 4.0 % had non-chromosomal syndromes. Among the 32 liveborn children, 56.3 % had reverse flow in the patent arterial duct, 25.0 % had major aortopulmonary collateral arteries (MAPCAs) with ductal agenesis and 18.7 % had a double supply. 17 pregnancies were terminated (34.0 %), there was 1 intrauterine fetal death (2.0 %), 1 neonatal death (2.0 %), and 6 deaths (12.0 %) in infancy. 25 of 30 (83.3 %) liveborn children with an intention to treat were alive at the latest follow-up. The mean follow-up among survivors was 10.0 years (range 6.5-15.1). 56.0 % of infants underwent staged repair, 44.0 % had one-stage complete repair. After exclusion of infants with additional chromosomal or syndromal anomalies, 88.9 % were healthy, and 11.1 % had mild limitations. The presence of MAPCAs did not differ significantly between survivors and non-survivors (p = 0.360), between one-stage or staged repair (p = 0.656) and healthy and impaired infants (p = 0.319). CONCLUSION: The prognosis in cases without chromosomal or syndromal anomalies is good. MAPCAs did not influence prognosis or postoperative health. The incidence of repeat interventions due to recurrent stenoses is significantly higher after staged compared with single-stage repair.

Severe Pulmonary Stenosis or Atresia with Intact Ventricular Septum in the Fetus: The Natural History.

PURPOSE: To assess the intrauterine course, the outcome, and to establish a new prenatal echocardiographic scoring system to predict biventricular (BV) versus univentricular (UV) outcome of fetuses with severe pulmonary stenosis or atresia with intact ventricular septum (PSAIVS). METHODS: All cases of PSAIVS diagnosed prenatally over a period of 14years were retrospectively collected in 2 tertiary referral centers. RESULTS: Forty-nine fetuses with PSIVS (n = 11) or PAIVS (n = 38) were identified prenatally. Nineteen (38.8%) fetuses had additional ventriculocoronary connections (VCCs) and 21 (42.9%) fetuses had right ventricular hypoplasia. Four (8.2%) pregnancies were terminated, 2 (4.1%) ended in intrauterine fetal death, 4 (8.2%) in neonatal death, and 5 (10.2%) children died in infancy or childhood, including one case with compassionate care. Thirty-four of 44 (77.3%) fetuses with the intention-to-treat were alive at latest follow-up, 25 (73.5%) with BV, and 9 (26.5%) with UV circulation. Most significant predictive markers of UV circulation were Vmax of tricuspid regurgitation (TR) <2 m/s, right ventricle/left ventricle length ratio ≤0.6, and presence of VCC. A scoring system including these 3 markers had 100% sensitivity and 100% specificity predicting an UV outcome if more than one of these criteria was fulfilled. All 25 liveborn infants that were suitable for BV repair survived, whereas only 9 out of 14 candidates for UV repair survived. None of the 14 fetuses with predicted UV outcome would have met the inclusion criteria for fetal intervention, as 10 of them had VCC and the remaining 4 had absent TR or Vmax <2 m/s. CONCLUSION: The prognosis of prenatally diagnosed PSAIVS is good if BV circulation can be achieved, while postnatal mortality in UV circulation is high within the first 4 months of life. Postnatal outcome can be predicted prenatally with high accuracy using a simple scoring system. This information is mandatory for parental counseling and may be useful in selecting fetuses for intrauterine valvuloplasty.

Fetal Cardiac Intervention in Critical Aortic Stenosis with Severe Mitral Regurgitation, Severe Left Atrial Enlargement, and Restrictive Foramen Ovale.

OBJECTIVE: To assess the intrauterine course and outcome of fetal cardiac intervention (FCI) in fetuses with critical aortic stenosis (CAS), severe mitral regurgitation (MR), severe left atrial dilatation (LAD), and restrictive foramen ovale (RFO) or intact atrial septum. METHODS: All fetuses with a prenatal diagnosis of CAS, severe MR, severe LAD, and RFO were retrospectively collected in one tertiary center for fetal medicine over a period of 10 years. Video recordings, pre- and postnatal charts were reviewed for cardiac and extracardiac anomalies, intrauterine course, and postnatal outcome. RESULTS: Nineteen fetuses with CAS, severe MR, severe LAD, and RFO were diagnosed in the study period. In 5 cases, FCI was not considered as the parents either opted for expectative management or for termination. In the remaining 14 fetuses, 21 FCI were performed: 14 balloon valvuloplasties, 2 atrioseptostomies, and 5 fetal atrial stent insertions. Seven of 14 fetuses (50%) had fetal hydrops, 5 of 14 fetuses (36%) presented with intact atrial septum. Procedure-related death occurred in 5 fetuses after aortic valvuloplasty or concomitant atrioseptostomy but in none after fetal atrial stenting. Due to progressive hydrops, two terminations of pregnancy were performed. Among the 7 live births, 3 died in the neonatal period. The remaining 4 received single ventricle palliation, 2 following fetal aortic valvuloplasty and 2 after fetal atrial stent insertion. CONCLUSIONS: CAS with severe MR, severe LAD, and RFO has a high overall mortality even in cases undergoing intrauterine intervention. Parameters that accurately predict the intrauterine and postnatal outcome have yet to be defined.

The ß2 agonist terbutaline specifically decreases pulmonary arterial pressure under normoxia and hypoxia via α adrenoceptor antagonism.

Pulmonary hypertension is a severe, incurable disease with a poor prognosis. Although treatment regimens have improved during the last 2 decades, current pharmacologic strategies are limited and focus on the modulation of only a few pathways related to endothelin, NO, and prostacyclin signaling. Therefore, the identification of novel molecular targets is urgently needed. We found that the ß2 adrenoceptor (AR) agonists terbutaline (TER) and salbutamol induced a dose-dependent vasorelaxation in large pulmonary arteries but not aortas of mouse. This effect was found to be independent of ß ARs and the endothelium but was determined by the type of the preconstrictor. Vasodilation by ß2 AR agonists occurred after pretreatment of pulmonary arteries with phenylephrine and serotonin, both agonists of α1 ARs, but was absent after preconstriction with the thromboxane analog U46619. These data indicated α-adrenolytic activity of ß2 AR agonists, which was confirmed by a right shift of the phenylephrine dose-response curve by TER. This effect was physiologically relevant because TER also relaxed small intrapulmonary arteries in lung slices and diminished pulmonary arterial pressure in an isolated perfused lung model under normoxia and hypoxia. Finally, TER applied as an aerosol also selectively decreased pulmonary arterial pressure without effects on systemic blood pressure and heart rate in mouse in vivo. Thus, ß2 AR agonists display α-adrenolytic activity in pulmonary arteries ex vivo and in vivo, and may provide a novel option to reduce pulmonary arterial pressure in pulmonary hypertension.-Neumann, V., Knies, R., Seidinger, A., Simon, A., Lorenz, K., Matthey, M., Breuer, J., Wenzel, D. The ß2 agonist terbutaline specifically decreases pulmonary arterial pressure under normoxia and hypoxia via α adrenoceptor antagonism.

Prenatal diagnosis, associated findings and postnatal outcome of fetuses with double outlet right ventricle (DORV) in a single center.

Objective To assess the spectrum of associated anomalies, the intrauterine course, postnatal outcome and management of fetuses with double outlet right ventricle (DORV). Methods All cases of DORV diagnosed prenatally over a period of 8 years were retrospectively collected in a single tertiary referral center. All additional prenatal findings were assessed and correlated with the outcome. The accuracy of prenatal diagnosis was assessed. Results Forty-six cases of DORV were diagnosed prenatally. The mean gestational age at first diagnosis was 21+4 weeks (range, 13-37). A correct prenatal diagnosis of DORV was made in 96.3% of the cases. If the relation of the great arteries, the position of the ventricular septal defect (VSD) and additional cardiac anomalies are taken into account, the prenatal diagnosis was correct in 92.6% of the cases. One case was postnatally classified as transposition of the great arteries with subpulmonary VSD and was excluded from further analysis. A total of 41 (91.1%) fetuses with DORV had major additional cardiac anomalies, 30 (66.7%) had extracardiac anomalies and 13 (28.9%) had chromosomal or syndromal anomalies. Due to their complex additional anomalies, five (11.1%) of our 45 fetuses had multiple malformations and were highly suspicious for non-chromosomal genetic syndromes, although molecular diagnosis could not be provided. Disorders of laterality occurred in 10 (22.2%) fetuses. There were 17 terminations of pregnancy (37.8%), two (4.4%) intrauterine and seven (15.6%) postnatal deaths. Nineteen of 22 (86.4%) live-born children with an intention to treat were alive at last follow-up. The mean follow-up among survivors was 32 months (range, 2-72). Of 21 children who had already undergone postnatal surgery, eight (38.1%) achieved biventricular repair and 13 (61.9%) received univentricular palliation. One recently born child is still waiting for surgery. All children predicted prenatally to need a single ventricle palliation, and all children predicted to achieve biventricular repair, ultimately received the predicted type of surgery. After surgery, 14 of 18 (77.8%) children were healthy without any impairment. Conclusion DORV is a rare and often complex cardiac anomaly that can be diagnosed prenatally with high precision. DORV is frequently associated with major additional anomalies, leading to a high intrauterine and postnatal loss rate due to terminations or declined postnatal therapy. Without additional anomalies, the prognosis is good, although approximately 60% of children will have single ventricle palliation.

Ebstein's Anomaly of the Tricuspid Valve in the Fetus - A Multicenter Experience.

Purpose To assess the spectrum of associated anomalies, the intrauterine course, the outcome and possible prognostic markers in prenatally diagnosed Ebstein's anomaly (EA). Materials and Methods All cases of EA diagnosed over a period of 13 years with a minimum follow-up of 1 year were retrospectively collected in 4 tertiary referral centers in Germany. Results In the study period 76 cases of EA were prenatally diagnosed. The mean gestational age at diagnosis was 25.0 weeks (range: 13 - 35). 41 (53.9 %) cases were isolated and 35 (46.1 %) had other cardiac and/or extracardiac anomalies. 19 (25.0 %) pregnant women opted for termination of pregnancy, intrauterine fetal death occurred in 7 cases (9.2 %), neonatal death in 14 cases (18.4 %), death in infancy or childhood in 9 cases (11.8 %) and 27 children (35.5 %) were alive at the last follow-up. After exclusion of terminations, the only parameter inversely correlated with intrauterine survival was hydrops fetalis. Prognostic parameters significantly associated with postnatal non-survival were an abnormal Celermajer index (right atrium/heart ratio > 0.7), cardiomegaly (cardiothoracic circumference ratio > 0.5), absence of antegrade flow over the pulmonary valve and earlier diagnosis in pregnancy. Conclusion Prenatally diagnosed EA has a high morbidity and mortality with the highest loss rate in the intrauterine and neonatal period. In our study, hydrops fetalis was the only parameter significantly associated with intrauterine demise, while other prenatal markers were only significantly associated with postnatal mortality.

Comparison of stroke volumes assessed by three-dimensional echocardiography and transpulmonary thermodilution in a pediatric animal model.

To compare stroke volumes (SV) in small hearts assessed by real-time three-dimensional echocardiography (3DE) with SV measured by transpulmonary thermodilution (TPTD) and continuous pulse contour analysis (PC) under various hemodynamic conditions. In thirteen anesthetized piglets (range 3.6-7.1 kg) SV were measured by 3DE, TPTD and PC at baseline and during phenylephrine and esmolol administration. 3DE and TPTD measurements were done successively while SV calculated by PC was documented at the time of 3DE. 3DE and TPTD showed a good correlation (r2 = 0.74) and a bias of -1.3 ml (limits of agreement -4.1 to 1.5 ml). While TPTD measured higher SV than 3DE, both methods tracked SV changes with a concordance rate of 91 %. PC and 3DE showed a lower correlation coefficient of r2 = 0.57 and a bias of -2.1 ml (limits of agreement -5.9 to 1.8 ml). Inter- and intra-observer variability of SV measured by 3DE was good with a mean bias <5 %. SV3DE showed a small variance and tracked acute small changes in SV in acceptable concordance with TPTD. PC measured SV with a higher variance and mean difference compared to 3DE. In an experimental setting 3DE has the possibility to offer non-invasive assessments of ventricular volumes volume changes. To determine whether 3DE could be used for SV assessment in a clinical routine our results need confirmation in a clinical setting.

Foetal therapy: what works? Closed interatrial septum.

Hypoplastic left-heart syndrome and critical aortic stenosis with severely restricted or intact foramen ovale are associated with high neonatal mortality and poor long-term outcome. Despite accurate foetal diagnosis and successful postnatal catheter-based and surgical intervention, the 1-month survival rate is about 33%. Changes in pulmonary vascular architecture resulting in pulmonary hypertension result in important long-term morbidity. Prenatal relief of left atrial and pulmonary hypertension may promote normal pulmonary vascular and parenchymal development and improve short- and long-term outcomes. Foetal atrial balloon septostomy, laser perforation, and stenting of the foetal interatrial septum are the current options for foetal therapy. This paper provides an overview of foetal diagnosis, selection of patients for foetal intervention, and interventional techniques, and also reviews the current status of foetal and postnatal outcomes after intrauterine intervention.

In a porcine model of implantable pacemakers for pediatric unilateral diaphragm paralysis, the phrenic nerve is the best target.

BACKGROUND: A frequent complication of Fontan operations is unilateral diaphragmatic paresis, which leads to hemodynamic deterioration of the Fontan circulation. A potential new therapeutic option is the unilateral diaphragmatic pacemaker. In this study, we investigated the most effective stimulation location for a potential fully implantable system in a porcine model. METHODS: Five pigs (20.8 ± 0.95 kg) underwent implantation of a customized cuff electrode placed around the right phrenic nerve. A bipolar myocardial pacing electrode was sutured adjacent to the motor point and peripherally at the costophrenic angle (peripheral diaphragmatic muscle). The electrodes were stimulated 30 times per minute with a pulse duration of 200 µs and a stimulation time of 300 ms. Current intensity was the only variable changed during the experiment. RESULTS: Effective stimulation occurred at 0.26 ± 0.024 mA at the phrenic nerve and 7 ± 1.22 mA at the motor point, a significant difference in amperage (p = 0.005). Even with a maximum stimulation of 10 mA at the peripheral diaphragm muscle, however, no effective stimulation was observed. CONCLUSION: The phrenic nerve seems to be the best location for direct stimulation by a unilateral thoracic diaphragm pacemaker in terms of the required amperage level in a porcine model.

Pulmonary blood flow in children with univentricular heart and unilateral diaphragmatic paralysis.

OBJECTIVES: Spontaneous breathing has an important effect on pulmonary arterial blood flow in patients with Glenn/Fontan circulation. Unilateral diaphragmatic paralysis (DP) is a frequent complication after heart surgery in congenital heart disease. The aim of this study was to investigate the influence of unilateral DP on blood flow distribution in the pulmonary arteries with Glenn/Fontan circulation. METHODS: Magnetic resonance phase-contrast imaging was used to evaluate stroke volume index (SVI) in the left and right pulmonary arteries in patients with Glenn/Fontan circulation with unilateral DP. Data for 18 patients with univentricular heart and unilateral DP were analysed, 8 in the Glenn stage and 10 in the Fontan stage. Ten patients had right-sided DP, and 8 had left-sided DP. A diaphragmatic plication was performed in 7 patients. The control group consisted of 36 patients with Glenn (n = 16)/Fontan (n = 20) circulation without DP. RESULTS: In both left- and right-sided DP, the SVI to the ipsilateral side was significantly lower than in controls [2.81 (1.45-4.50) ml/m2 left vs 11.97 (7.36-16.37) ml/m2 in controls, P < 0.0002; 8.2 (4.49-12.64) ml/m2 with right vs 12.64 (9.66-16.61) ml/m2 in controls; P = 0.0284]. The SVI to the contralateral side showed a slight but non-significant increase in the presence of unilateral DP. CONCLUSIONS: Unilateral DP in patients with Glenn/Fontan circulation has a negative impact on pulmonary arterial SVI on the side of the paralysis.

Evaluation of the MRI compatibility of PET detectors modules for organ-specific inserts in a 3T and 7T MRI scanner.

BACKGROUND: Simultaneous positron emission tomography (PET)/magnetic resonance imaging (MRI) scanners and inserts are valuable tools for accurate diagnosis, treatment planning, and monitoring due to their complementary information. However, the integration of a PET system into an MRI scanner presents technical challenges for a distortion-free operation. PURPOSE: We aim to develop a PET insert dedicated to breast imaging in combination with the 3T PET/MRI scanner Biograph mMR (Siemens Healthineers) as well as a brain PET insert for the 7T MRI scanner MAGNETOM Terra (Siemens Healthineers). For this development, we selected as a basis the C13500 series PET modules (Hamamatsu Photonics K.K.) as they offer an all-in-one solution with a scalable, modular design for compact integration with state-of-the-art performance. The original PET modules were not designed to be operated with an MRI scanner, therefore we implemented several modifications such as signal transmission via plastic optical fiber, radio frequency (RF) shielding of the front-end electronics, and filter for the power supply lines. In this work, we evaluated the mutual MRI compatibility between the modified PET modules and the 3T and 7T MRI scanner. METHODS: We used a proof-of-concept setup with two detectors to comprehensively evaluate a potential distortion of the performance of the modified PET modules whilst exposing them to a variety of MR sequences up to the peak operation conditions of the Biograph mMR. A method using the periodicity of the sequences to identify distortions of the PET events in the phase of RF pulse transmission was introduced. Vice versa, the potential distortion of the Biograph mMR was evaluated by vendor proprietary MRI compatibility test sequences. Afterwards, these studies were extended to the MAGNETOM Terra. RESULTS: No distortions were introduced by gradient field switching (field strength up to 20 mT/m at a slew rate of 66.0 T/ms-1 ). However, RF pulse transmission induced a reduction of the single event rate from 33.0 kcounts/s to 32.0 kcounts/s and a degradation of the coincidence resolution time from 251 to 299 ps. Further, the proposed method revealed artifacts in the energy and timing histograms. Finally, by using the front-end filters it was possible to prevent any RF pulse induced distortion of event rate, energy, or time stamps even for a 700° flip angle (45.5 µT) sequence. The evaluations to assess potential distortions of the MRI scanner showed that carefully designed RF shielding boxes for the PET modules were required to prevent distortion of the RF spectra. The increase in B0 field inhomogeneity of 0.254 ppm and local changes of the B1 field of 12.5% introduced by the PET modules did not qualitatively affect the MR imaging with a spin echo and MPRAGE sequence for the Biograph mMR and the MAGNETOM Terra, respectively. CONCLUSION: Our study demonstrates the feasibility of using a modified version of the PET modules in combination with 3T and 7T MRI scanners. Building upon the encouraging MRI compatibility results from our proof-of-concept detectors, we will proceed to develop PET inserts for breast and brain imaging using these modules.

Propofol administration to the fetal-maternal unit reduces cardiac injury in late-preterm lambs subjected to severe prenatal asphyxia and cardiac arrest.

BACKGROUND: Cardiac dysfunction is reported to occur after severe perinatal asphyxia. We hypothesized that anesthesia of the mother with propofol during emergency cesarean section (c-section) would result in less cardiac injury (troponin T) in preterm fetuses exposed to global severe asphyxia in utero than anesthesia with isoflurane. We tested whether propofol decreases the activity of proapoptotic caspase-3 by activating the antiapoptotic AKT kinase family and the signal transducer and activator of transcription-3 (STAT-3). METHODS: Pregnant ewes were randomized to receive either propofol or isoflurane anesthesia. A total of 44 late-preterm lambs were subjected to in utero umbilical cord occlusion (UCO), resulting in asphyxia and cardiac arrest, or sham treatment. After emergency c-section, each fetus was resuscitated, mechanically ventilated, and supported under anesthesia for 8 h using the same anesthetic as the one received by its mother. RESULTS: At 8 h after UCO, the fetuses whose mothers had received propofol anesthesia had lower plasma troponin T levels, and showed a trend toward a higher median left ventricular ejection fraction (LVEF) of 84% as compared with 74% for those whose mothers had received isoflurane. Postasphyxia activation of caspase-3 was lower in association with propofol anesthesia than with isoflurane. Postasphyxia levels of STAT-3 and the AKT kinase family rose 655% and 500%, respectively with the use of propofol anesthesia for the mother. CONCLUSION: The use of propofol for maternal anesthesia results in less cardiac injury in late-preterm lambs subjected to asphyxia than the use of isoflurane anesthesia. The underlying mechanism may be activation of the antiapoptotic STAT-3 and AKT pathways.

A porcine model of postoperative hemi-diaphragmatic paresis to evaluate a unilateral diaphragmatic pacemaker.

Unilateral phrenic nerve damage is a dreaded complication in congenital heart surgery. It has deleterious effects in neonates and children with uni-ventricular circulation. Diaphragmatic palsy, caused by phrenic nerve damage, impairs respiratory function, especially in new-borns, because their respiration depends on diaphragmatic contractions. Furthermore, Fontan patients with passive pulmonary perfusion are seriously affected by phrenic nerve injury, because diaphragmatic contraction augments pulmonary blood flow. Diaphragmatic plication is currently employed to ameliorate the negative effects of diaphragmatic palsy on pulmonary perfusion and respiratory mechanics. This procedure attenuates pulmonary compression by the abdominal contents. However, there is no contraction of the plicated diaphragm and consequently no contribution to the pulmonary blood flow. Hence, we developed a porcine model of unilateral diaphragmatic palsy in order to evaluate a diaphragmatic pacemaker. Our illustrated step-by-step description of the model generation enables others to replicate and use our model for future studies. Thereby, it might contribute to investigation and advancement of potential improvements for these patients.

Sharing social media data: The role of past experiences, attitudes, norms, and perceived behavioral control.

Social media data (SMD) have become an important data source in the social sciences. The purpose of this paper is to investigate the experiences and practices of researchers working with SMD in their research and gain insights into researchers' sharing behavior and influencing factors for their decisions. To achieve these aims, we conducted a survey study among researchers working with SMD. The questionnaire covered different topics related to accessing, (re)using, and sharing SMD. To examine attitudes toward data sharing, perceived subjective norms, and perceived behavioral control, we used questions based on the Theory of Planned Behavior (TPB). We employed a combination of qualitative and quantitative analyses. The results of the qualitative analysis show that the main reasons for not sharing SMD were that sharing was not considered or needed, as well as legal and ethical challenges. The quantitative analyses reveal that there are differences in the relative importance of past sharing and reuse experiences, experienced challenges, attitudes, subjective norms, and perceived behavioral control as predictors of future SMD sharing intentions, depending on the way the data should be shared (publicly, with restricted access, or upon personal request). Importantly, the TPB variables have predictive power for all types of SMD sharing.