[Ethical Attitudes and Handling in Prenatal Conflict Situations - A Survey among Obstetricians and Prenatal Diagnosticians in Germany]. / Ethische Haltungen und Umgang in pränatalen Konfliktsituationen ­ eine Umfrage unter Geburtshelfern und Pränataldiagnostikern in Deutschland.

OBJECTIVE: Various studies have shown that belonging to a professional group has an influence on ethical attitudes. The aim of this study was to assess and compare the attitudes and approaches of obstetrical specialists and prenatal diagnosticians in prenatal conflict situations. METHODS: Explorative cross-sectional online survey among tertiary perinatal care centers and prenatal diagnosticians with DEGUM Level II/III in Germany. The questionnaire included questions on ethical attitudes in the perinatal context and a case presentation of a fetal hypoplastic left heart syndrome. RESULTS: The response rate was 57.1% (310/543). 55.5% of the respondents practiced both obstetrics and prenatal diagnostics, 24.5% exclusively prenatal diagnostics, and 14.2% purely obstetrics. 27% agreed with the statement "An uncertain prognosis justifies pregnancy termination". For complex fetal malformations joint interdisciplinary counseling was advocated by 98.3%. Addressing the option of postnatal palliative treatment in a case of a hypoplastic left heart syndrome was accepted by 84.3% across all professional groups, while mentioning fetocide was more frequently cited as an option by prenatal diagnosticians than by obstetricians (57.7% vs. 34.1%). CONCLUSION: Interdisciplinary prenatal parental counseling in complex fetal malformations is uniformly advocated by prenatal diagnosticians and obstetricians in Germany. However, different ethical attitudes appear among specialists groups with regard to the option of termination of pregnancy.

Conservation and divergence of meiotic DNA double strand break forming mechanisms in Arabidopsis thaliana.

In the current meiotic recombination initiation model, the SPO11 catalytic subunits associate with MTOPVIB to form a Topoisomerase VI-like complex that generates DNA double strand breaks (DSBs). Four additional proteins, PRD1/AtMEI1, PRD2/AtMEI4, PRD3/AtMER2 and the plant specific DFO are required for meiotic DSB formation. Here we show that (i) MTOPVIB and PRD1 provide the link between the catalytic sub-complex and the other DSB proteins, (ii) PRD3/AtMER2, while localized to the axis, does not assemble a canonical pre-DSB complex but establishes a direct link between the DSB-forming and resection machineries, (iii) DFO controls MTOPVIB foci formation and is part of a divergent RMM-like complex including PHS1/AtREC114 and PRD2/AtMEI4 but not PRD3/AtMER2, (iv) PHS1/AtREC114 is absolutely unnecessary for DSB formation despite having a conserved position within the DSB protein network and (v) MTOPVIB and PRD2/AtMEI4 interact directly with chromosome axis proteins to anchor the meiotic DSB machinery to the axis.

The Arabidopsis SAFEGUARD1 suppresses singlet oxygen-induced stress responses by protecting grana margins.

Singlet oxygen (1O2), the major reactive oxygen species (ROS) produced in chloroplasts, has been demonstrated recently to be a highly versatile signal that induces various stress responses. In the fluorescent (flu) mutant, its release causes seedling lethality and inhibits mature plant growth. However, these drastic phenotypes are suppressed when EXECUTER1 (EX1) is absent in the flu ex1 double mutant. We identified SAFEGUARD1 (SAFE1) in a screen of ethyl methanesulfonate (EMS) mutagenized flu ex1 plants for suppressor mutants with a flu-like phenotype. In flu ex1 safe1, all 1O2-induced responses, including transcriptional rewiring of nuclear gene expression, return to levels, such as, or even higher than, those in flu Without SAFE1, grana margins (GMs) of chloroplast thylakoids (Thys) are specifically damaged upon 1O2 generation and associate with plastoglobules (PGs). SAFE1 is localized in the chloroplast stroma, and release of 1O2 induces SAFE1 degradation via chloroplast-originated vesicles. Our paper demonstrates that flu-produced 1O2 triggers an EX1-independent signaling pathway and proves that SAFE1 suppresses this signaling pathway by protecting GMs.

German obstetrician's self-reported attitudes and handling in threatening preterm birth at the limits of viability.

OBJECTIVES: Antenatal treatment and information influences the course of pregnancy and parental decision-making in cases of threatened prematurity on the borderline of viability. Numerous studies have shown significant interprofessional differences in assessing ethical boundary decisions; hence, this study aimed to evaluate obstetricians attitudes, practices and antenatal parental counseling regarding threatened preterm birth in Germany. METHODS: An anonymous online questionnaire was administered to 543 obstetricians at tertiary perinatal centers and prenatal diagnostic centers in Germany. The survey contained questions on basic ethical issues assessed using the Likert scale and a case vignette regarding the practical procedures of an imminent extreme premature birth at 23 1/7 gestational weeks. RESULTS: In the case of unstoppable preterm birth, 15 % of clinicians said they would carry out a cesarean section; however, specialists from centers with a high number of very low birth weight infants would do so significantly more often. Among respondents, 29.8 % did not take any therapeutic measures without discussing the child's treatment options with their parents, 19.9 % refused to offer actionable advice to the parents, and 57 % said they would advise parents to seek intensive care treatment for the child with the option of changing treatment destination in the event of serious complications. Moreover, 84 % said they would provide information together with neonatologists. CONCLUSIONS: Joint counseling with neonatologists is widely accepted. The size of the perinatal center significantly influences the practical approach to threatened preterm births. Respect for parents' decision-making autonomy regarding the child's treatment options is central and influences therapy initiation.

Impact of interdisciplinary counselling for parental decision-making in cases of pregnancies with prenatally diagnosed CHD.

INTRODUCTION: Parental counselling after antenatal diagnosis of a congenital heart defect requires a high degree of professional and emotional competence and ultimately a sense of responsibility on the part of the consulting physicians. However, little is known about parents` perceptions and evaluation of these consultations. MATERIAL/METHODS: Survey on 425 women who received interdisciplinary counselling after antenatal diagnosis of a complex fetal congenital heart defect in a specialized prenatal outpatient clinic with an affiliated paediatric heart centre. Two questionnaires were used to retrospectively evaluate the parental perception and impact on counselling, particularly on decision-making. Questionnaires differed between women conceiving the child and women who terminated the pregnancy. RESULTS: 400 women continued, 25 women terminated the pregnancy after diagnosis and counselling. Good quality of life was reported for 68% of the children, 15% died postnatally in the further course. 95% rated the counselling as good or very good regardless of the child´s outcome. 73% described the counselling as highly important for their subsequent decision. The possibility of termination of pregnancy was discussed with 37% of the respondents, 22% of them found it outrageous or very distressing. Of all respondents, one woman would have made a different decision regarding continuation of the pregnancy in retrospect. CONCLUSION: Retrospectively, parents rate prenatal counselling extremely positively, irrespective of the severity of the child´s heart defect. It can be assumed that the consistent joint interdisciplinary consultation and the high reputation of the cooperating heart centre have had an influence on the below-average rate of termination of pregnancy.

Inactivation of cytosolic FUMARASE2 enhances growth and photosynthesis under simultaneous copper and iron deprivation in Arabidopsis.

Copper (Cu) and iron (Fe) are essential for plant growth and are often in short supply under natural conditions. Molecular responses to simultaneous lack of both metals (-Cu-Fe) differ from those seen in the absence of either alone. Metabolome profiling of plant leaves previously revealed that fumarate levels fall under -Cu-Fe conditions. We employed lines lacking cytosolic FUMARASE2 (FUM2) activity to study the impact of constitutive suppression of cytosolic fumarate synthesis on plant growth under Cu and/or Fe deficiency. In fum2 mutants, photosynthesis and growth were less impaired under -Cu-Fe conditions than in wild-type (WT) seedlings. In particular, levels of photosynthetic proteins, chloroplast ultrastructure, amino acid profiles and redox state were less perturbed by simultaneous Cu-Fe deficiency in lines that cannot produce fumarate in the cytosol. Although cytosolic fumarate has been reported to promote acclimation of photosynthesis to low temperatures when metal supplies are adequate, the photosynthetic efficiency of fum2 lines grown under Cu-Fe deficiency in the cold was higher than in WT. Uptake and contents of Cu and Fe are similar in WT and fum2 plants under control and -Cu-Fe conditions, and lack of FUM2 does not alter the ability to sense metal deficiency, as indicated by marker gene expression. Collectively, we propose that reduced levels of cytosolic fumarate synthesis ultimately increase the availability of Fe for incorporation into metalloproteins.

An endocytic-secretory cycle participates in Toxoplasma gondii in motility.

Apicomplexan parasites invade host cells in an active process involving their ability to move by gliding motility. While the acto-myosin system of the parasite plays a crucial role in the formation and release of attachment sites during this process, there are still open questions regarding the involvement of other mechanisms in parasite motility. In many eukaryotes, a secretory-endocytic cycle leads to the recycling of receptors (integrins), necessary to form attachment sites, regulation of surface area during motility, and generation of retrograde membrane flow. Here, we demonstrate that endocytosis operates during gliding motility in Toxoplasma gondii and appears to be crucial for the establishment of retrograde membrane flow, because inhibition of endocytosis blocks retrograde flow and motility. We demonstrate that extracellular parasites can efficiently incorporate exogenous material, such as labelled phospholipids, nanogold particles (NGPs), antibodies, and Concanavalin A (ConA). Using labelled phospholipids, we observed that the endocytic and secretory pathways of the parasite converge, and endocytosed lipids are subsequently secreted, demonstrating the operation of an endocytic-secretory cycle. Together our data consolidate previous findings, and we propose an additional model, working in parallel to the acto-myosin motor, that reconciles parasite motility with observations in other eukaryotes: an apicomplexan fountain-flow-model for parasite motility.

Impaired chloroplast positioning affects photosynthetic capacity and regulation of the central carbohydrate metabolism during cold acclimation.

Photosynthesis and carbohydrate metabolism of higher plants need to be tightly regulated to prevent tissue damage during environmental changes. The intracellular position of chloroplasts changes due to a changing light regime. Chloroplast avoidance and accumulation response under high and low light, respectively, are well known phenomena, and deficiency of chloroplast movement has been shown to result in photodamage and reduced biomass accumulation. Yet, effects of chloroplast positioning on underlying metabolic regulation are less well understood. Here, we analysed photosynthesis together with metabolites and enzyme activities of the central carbohydrate metabolism during cold acclimation of the chloroplast unusual positioning 1 (chup1) mutant of Arabidopsis thaliana. We compared cold acclimation under ambient and low light and found that maximum quantum yield of PSII was significantly lower in chup1 than in Col-0 under both conditions. Our findings indicated that net CO2 assimilation in chup1 is rather limited by biochemistry than by photochemistry. Further, cold-induced dynamics of sucrose phosphate synthase differed significantly between both genotypes. Together with a reduced rate of sucrose cycling derived from kinetic model simulations our study provides evidence for a central role of chloroplast positioning for photosynthetic and metabolic acclimation to low temperature.

Acute treatment of critical vascular stenoses with a bioabsorbable magnesium scaffold in infants with CHDs.

BACKGROUND: Post-operative severe vascular stenosis and proliferating endothelial tissue lead to severe circulatory disorders and impair organ perfusion. Bioabsorbable magnesium scaffolds may help to overcome these obstructions without leaving obstructing stent material. We analyse their role in the treatment of vascular stenosis in infants. METHODS: Since 2016, 15 magnesium scaffolds with a diameter of 3.5 mm were implanted in 9 patients aged 15 days to 7.6 years. Eight scaffolds were implanted in pulmonary venous restenoses, five in pulmonary arterial stenosis including one in-stent stenosis, one into a stenotic brachiocephalic artery, and one in a recurrent innominate vein thrombosis. RESULTS: All patients clinically improved after the implantation of a scaffold. The magnesium scaffolds lost integrity after 30-48 days (mean 42 days). The innominate vein thrombosed early, while all other vessels remained open. Two patients died after 1.3 and 14 weeks not related to the scaffolds. Five patients needed further balloon dilations or stent implantations after the scaffold had fractured. At first recatheterisation after in mean 2.5 months, the mean minimum/maximum diameter in relation to the scaffold's original diameter was 89%/99% in the arterial implantations (n = 6) and 66%/77% in the pulmonary venous implantations. CONCLUSIONS: The magnesium scaffolds can be used as a bridging solution to treat severe vascular stenosis in different locations. Restenosis can occur after degradation and make further interventions necessary, but neither vessel growth nor further interventions are hindered by stent material. Larger diameters may improve therapeutic options.

End-of-Life Decisions 20 Years after EURONIC: Neonatologists' Self-Reported Practices, Attitudes, and Treatment Choices in Germany, Switzerland, and Austria.

OBJECTIVE: To assess changes in attitudes of neonatologists regarding the care of extremely preterm infants and parental involvement over the last 20 years. STUDY DESIGN: Internet-based survey (2016) involving 170 tertiary neonatal intensive care units in Austria, Switzerland, and Germany using the European Project on Parents' Information and Ethical Decision Making in Neonatal Intensive Care Units questionnaire (German edition) with minor modifications to the original survey from 1996 to 1997. RESULTS: The 2016 survey included 104 respondents (52.5% response rate). In 2016, significantly more neonatologists reported having ever withheld intensive care treatment (99% vs 69%) and withdrawn mechanical ventilation (96% vs 61%) or life-saving drugs (99% vs 79%), compared with neonatologists surveyed in 1996-1997. Fewer considered limiting intensive care as a slippery slope possibly leading to abuse (18% vs 48%). In the situation of a deteriorating clinical condition despite all treatment, significantly more neonatologists would ask parental opinion about continuation of intensive care (49% vs 18%). In 2016, 21% of German neonatologists would resuscitate a hypothetical infant at the limits of viability, even against parental wishes. CONCLUSIONS: Withholding or withdrawing intensive care for extremely preterm infants at the limits of viability with parental involvement has become more acceptable than it was 20 years ago. However, resuscitating extremely preterm infants against parental wishes remains an option for up to one-fifth of the responding neonatologists in this survey.

[Human patient simulators for training in emergency surgery : Needs, status quo and potential]. / Technische Trainingsmodelle für die notfallchirurgische Ausbildung : Bedarf, Status quo und Potenzial.

Surgical providers must maintain currency and competency for low-volume high-risk procedures for optimal outcomes. There are currently a number of methods available to train for these rare but vital skills, ranging from simple to complex and inexpensive to expensive. Traditionally, these skills have been taught using human cadaveric and animal models, which are limited by availability (cadavers) and social acceptability (animals). As such, there is a need to utilize advances in educational and simulation technologies to refine and develop consensus-based, validated, tissue-realistic, anatomically correct and cost-effective training tools to teach these vital skills. Partially perfused human cadavers have recently been shown to be an important adjunct to established trauma training. Human patient simulators (HPS) and the associated technology is rapidly expanding, but currently lack consistent realism to be used for competence training, when compared to traditional models and are currently cost-prohibitive. It will be important for surgical trainers and trainees to remain engaged and facilitate the development of realistic cost-effective training tools.

[Aerobic exercises worsen the detection threshold of short H2S pulses]. / Aerobe Belastung verschlechtert die Wahrnehmungsschwelle kurzer H2S-Impulse.

BACKGROUND: Whether smelling is reduced during aerobic exercise is described contradictorily in the sparse literature. MATERIAL AND METHODS: To clarify this question, in healthy subjects the passive detection thresholds for short H2S stimuli were determined by means of a flow olfactometer in an inspiration-synchronous manner during nasal breathing in a staircase procedure during a resting phase, a subsequent submaximal load on a bicycle ergometer and a subsequent recovery phase. In parallel, the measurements of heart rate, blood pressure, blood lactate and body temperature were monitored to confirm an aerobic exercise. RESULTS: The participants achieved the highest values for the detection threshold in the load phase. By means of rm-ANOVA and post-hoc tests, a significant difference in the mean values of detection thresholds between the measurements at rest and during cycling as well as between the recovery and load phases was observed. However, the mean values of the detection thresholds between the resting and recovery phases did not differ. CONCLUSION: The worsening of olfactory detection thresholds during acute aerobic physical exercise and their immediate improvement during recovery phase to rest values suggests that the detection threshold is influenced by exercise. The most probable cause for this is a dilution effect caused by additional inflowing neutral ambient air in the case of forced nasal breathing.

Targeted gene exchange in plant cells mediated by a zinc finger nuclease double cut.

Genome modification by homology-directed repair (HDR) is an attractive tool for the controlled genetic manipulation of plants. Here, we report the HDR-mediated gene exchange of expression cassettes in tobacco BY-2 cells using a designed zinc finger nuclease (ZFN). The target contained a 7-kb fragment flanked by two ZFN cutting sites. That fragment was replaced with a 4-kb donor cassette, which integrates gene markers for selection (kanamycin resistance) and for scoring targeting (red fluorescent protein, RFP). Candidates resulting from cassette exchange were identified by molecular analysis of calli generated by transformation via direct DNA delivery. The precision of HDR-mediated donor integration was evaluated by Southern blot analysis, sequencing of the integration locus and analysis of RFP fluorescence by flow cytometry. Screening of 1326 kanamycin-resistant calli yielded 18 HDR events, 16 of which had a perfect cassette exchange at the insert junction and 13 of which produced functional RFP. Our results demonstrate that ZFN-based HDR can be used for high frequency, precise, targeted exchange of fragments of sizes that are commercially relevant in plants.

Genes of the dopaminergic system selectively modulate top-down but not bottom-up attention.

Cognitive performance is modulated by the neurotransmitter dopamine (DA). Recently, it has been proposed that DA has a strong impact on top-down but not on bottom-up selective visual attention. We tested this assumption by analyzing the influence of two gene variants of the dopaminergic system. Both the catechol O-methyltransferase (COMT) protein and the dopamine transporter (DAT) protein are crucial for the degradation and inactivation of DA. These metabolizing proteins modulate the availability of DA, especially in the prefrontal cortex and basal ganglia. The functional COMT Val158Met polymorphism of the COMT gene represents two coding variants, valine and methionine. In Met allele carriers, the COMT activity is reduced three- to fourfold. A variable number of tandem repeats (VNTR) polymorphism exists in the DAT1 gene, which encodes DAT. The DAT density was reported to be about 50% higher for the DAT1 10-repeat than the DAT1 9-repeat allele. We assessed attention via two experimental tasks that predominantly measure either top-down processing (the Stroop task) or bottom-up processing (the Posner-Cuing task). Carriers of the Met allele of the COMT Val158Met polymorphism displayed better performance in the Stroop task, but did not outperform the other participants in the Posner-Cuing task. The same result was noted for carriers of the DAT1 10-repeat allele. From these findings, we suggest that normal variations of the dopaminergic system impact more strongly on top-down than on bottom-up attention.

Auditory distractor processing in sequential selection tasks.

In this review, we analyze the cognitive processes contributing to selection in audition. In particular, we focus on the processing of auditory distractors in sequential selection paradigms in which target stimuli are accompanied by distractors. We review the evidence from two established tasks, namely the auditory negative priming and the auditory distractor-response binding task, and discuss the cognitive mechanisms contributing to the results typically observed in these tasks. In fact, several processes have been suggested as to explain how distractors are processed and handled in audition; that is, auditory distractors can be inhibited, encoded with a do-not-respond-tag, integrated into a stimulus-response episode containing the response to the target, or upheld in working memory and matched/mismatched with the following distractor. In addition, variables possibly modulating these cognitive processes are discussed. Finally, auditory distractor processing is compared with distractor processing in vision.

Public Attitudes Toward Ethics and Practices in End-of-Life Decision-Making for Neonates.

Importance: Attitudes toward end-of-life decision-making in neonatology have been studied in physicians and other health care professionals and are mostly shaped by their clinical education and work experiences. In contrast, attitudes among the general public have not yet been investigated. Objective: To assess (1) attitudes in the general public toward euthanasia and withdrawal of life-prolonging treatment in neonates with severe life-limiting conditions, (2) knowledge of current German recommendations, and (3) values in the German society regarding ethical issues and proxy decisions at the beginning of life. Design, Setting, and Participants: This cross-sectional study was performed in Germany and used an exploratory design to analyze responses to an interview conducted by an independent, established commissioned polling institute in March and April 2022. Participants were 16 years or older, with German language fluency and comprehension and living in Germany. Main Outcomes and Measures: Knowledge about recommendations for euthanasia and withdrawal of life-prolonging treatment as well as personal attitudes toward (1) euthanasia and withdrawal of life-prolonging treatment and (2) surrogate end-of-life decision-making for newborn infants were assessed. Results: The study included 2116 participants (1077 females [50.9%]; mean [SD] age 52.1 [18.7] years). Of the participants, 16.8% (311 of 1851) reported knowing the German recommendations for euthanasia and withdrawal of life-prolonging treatment for neonates. Euthanasia and withdrawal of life-prolonging treatment were supported by 64.7% (1369 of 2116) and 77.9% (1649 of 2116) of respondents, respectively. Shared decision-making between parents and physicians for neonates in end-of-life situations was supported by 65.6% of participants (1388). In situations where shared decision-making was not possible, 73.4% of respondents (1019 of 1388) put the ultimate decision to the parents. The magnitude of the associations was low between sociodemographic factors and views on ethical issues and customary practices involved in end-of-life decisions for neonates. Conclusions and Relevance: Results of this cross-sectional study suggested that most respondents were not aware of the national German recommendations for euthanasia and withdrawal of life-prolonging treatment for sick and extremely preterm newborns. When counseling parents of periviable newborns, clinicians may need to exert more effort in explaining the legal and ethical framework; a highly individualized approach is warranted.

FGFR3 is a target of the homeobox transcription factor SHOX in limb development.

The short stature homeobox gene SHOX encodes a transcription factor which is important for normal limb development. In humans, SHOX deficiency has been associated with various short stature syndromes including Leri-Weill dyschondrosteosis (LWD), Langer mesomelic dysplasia and Turner syndrome as well as non-syndromic idiopathic short stature. A common feature of these syndromes is disproportionate short stature with a particular shortening of the forearms and lower legs. In our studies employing microarray analyses and cell culture experiments, we revealed a strong positive effect of SHOX on the expression of the fibroblast growth factor receptor gene FGFR3, another well-known factor for limb development. Luciferase reporter gene assays show that SHOX activates the extended FGFR3 promoter, and results from chromatin immunoprecipitation (ChIP)-sequencing, ChIP and electrophoretic mobility shift assay experiments suggest a direct binding of SHOX to multiple upstream sequences of FGFR3. To further investigate these regulations in a cellular system for limb development, the effect of viral overexpression of Shox in limb bud derived chicken micromass cultures was tested. We found that Fgfr3 was negatively regulated by Shox, as demonstrated by quantitative real-time polymerase chain reaction and in situ hybridization. This repressive effect might explain the almost mutually exclusive expression patterns of Fgfr3 and Shox in embryonic chicken limbs. A negative regulation that occurs mainly in the mesomelic segments, a region where SHOX is known to be strongly expressed, offers a possible explanation for the phenotypes seen in patients with FGFR3 (e.g. achondroplasia) and SHOX defects (e.g. LWD). In summary, these data present a link between two frequent short stature phenotypes.

Cerebral protection during controlled hypoperfusion in a piglet model: comparison of moderate (25°C) versus deep (18°C) hypothermia at various flow rates using intraoperative measurements and ex vivo investigation.

BACKGROUND: During surgical correction of complex cardiac anomalies, some degree of hypoperfusion may be required. The aim of this study was to evaluate the effectiveness and safety of controlled cerebral hypoperfusion at moderate (25°C) versus deep (18°C) hypothermia. METHODS: In this study, 56 female piglets (9.4 ± 0.8 kg, 3-4 weeks old) received cardiopulmonary bypass (CPB) at 25, 50, or 100% of the standard flow rate for 60 minutes of cardioplegic cardiac arrest. Body temperature was kept at 18, 25, and 37°C. Routine hemodynamic and functional parameters were measured online until 4 hours of reperfusion. Immunohistology was used to quantify heat shock protein 70 (HSP70) and nitrotyrosine (NO-Tyr) levels in the hippocampus; high-performance liquid chromatography was used to quantify jugular venous blood malondialdehyde (MDA) levels. RESULTS: Reduced CPB flow led to significant reduction of mean arterial pressure by 79%, reduction of jugular venous oxygen saturation (SvO2) by 47%, reduction of carotid blood flow by 92%, and increase of serum lactate by 350%. All these changes were significantly enhanced in the 37°C versus the 25 and the 18°C groups. Regional oxygen saturation (rSO2) was significantly reduced in the 37°C low flow groups. HSP70, NO-Tyr, and MDA were increased in the 25 and 50% flow groups (p < 0.05). There was a significant correlation between rSO2 and SvO2 (r = 0.61) and between SvO2 and HSP70 (r = - 0.72). CONCLUSIONS: Reduction in global blood flow during CPB leads to comparable biochemical changes in the hippocampus at 25 and 18°C. Regional oxygenation saturation, SvO2, and HSP70 are important parameters to evaluate the efficacy of further anti-ischemic therapies during surgical corrections.

Transcatheter closure of tubular PDA with amplatzer plug 4 in preterm infants weighing between 900 and 3,400†g: the pros and cons.

Objective: To our knowledge, no prior study has focused on the outcome of PDA occlusion using an Amplatzer™ Vascular Plug 4 (AP4) in ill preterm infants. This study aims to highlight the pros and cons of AP4 in this cohort. Methods: Between 2020 and 2022, 26 ill preterm infants underwent PDA closure in our centre. The median age, weight, and gestational age were 60 days (11-180 days), 1,900g (900-3,400 g), and 25 weeks (22-33 weeks), respectively. The indication of the intervention was hemodynamically significant PDA. A medical trial with non-steroid medication failed to close the ducts in all patients. Follow-up using echocardiography was done 24, 48, and 72 h after the intervention. Results: Of 26 ducts, 21 were successfully closed with AP4. Five ducts shorter than 7 mm were unsuitable for AP4 and were closed with the Amplatzer Piccolo device. The median radiation time was 4 min (3-9 min). No early plug-related complications or deaths were documented. Plug-related jailing of the left pulmonary artery as a late complication was 9.5%, and LPA reintervention was required. All ducts were closed after 48 h. Conclusion: Implantation of the AP4 using a 4 F 0.38 guide wire-compatible catheter without inserting a long sheath makes the closure of tubular ducts with this device feasible and uncomplicated with a short intervention time. However, the limited sizes with fixed lengths of the AP4 make it unsuitable for ducts wider than 4.5 mm and shorter than the chosen device length, which can increase the risk of significant left pulmonary stenosis. A wide range of plug diameters and lengths is required to accommodate the large and short ducts.