The Clinical Pulmonary Infection Score Combined with Procalcitonin and Lung Ultrasound (CPIS-PLUS), a Good Tool for Ventilator Associated Pneumonia Early Diagnosis in Pediatrics.

Ventilator-associated pneumonia (VAP) is common in Pediatric Intensive Care Units. Although early detection is crucial, current diagnostic methods are not definitive. This study aimed to identify lung ultrasound (LUS) findings and procalcitonin (PCT) values in pediatric patients with VAP to create a new early diagnosis score combined with the Clinical Pulmonary Infection Score (CPIS), the CPIS-PLUS score. Prospective longitudinal and interventional study. Pediatric patients with suspected VAP were included and classified into VAP or non-VAP groups, based on Centers of Disease Control (CDC) criteria for the final diagnosis. A chest-X-ray (CXR), LUS, and blood test were performed within the first 12 h of admission. CPIS score was calculated. A total of 108 patients with VAP suspicion were included, and VAP was finally diagnosed in 51 (47%) patients. CPIS-PLUS showed high accuracy in VAP diagnosis with a sensitivity (Sn) of 80% (95% CI 65-89%) and specificity (Sp) of 73% (95% CI 54-86%). The area under the curve (AUC) resulted in 0.86 for CPIS-PLUS vs. 0.61 for CPIS. In conclusion, this pilot study showed that CPIS-PLUS could be a potential and reliable tool for VAP early diagnosis in pediatric patients. Internal and external validations are needed to confirm the potential value of this score to facilitate VAP diagnosis in pediatric patients.

Pharmacological reprogramming of zebrafish lateral line supporting cells to a migratory progenitor state.

In the zebrafish lateral line, non-sensory supporting cells readily re-enter the cell cycle to generate new hair cells and supporting cells during homeostatic maintenance and following damage to hair cells. This contrasts with supporting cells from mammalian vestibular and auditory sensory epithelia which rarely re-enter the cell cycle, and hence loss of hair cells results in permanent sensory deficit. Lateral line supporting cells are derived from multipotent progenitor cells that migrate down the trunk midline as a primordium and are deposited to differentiate into a neuromast. We have found that we can revert zebrafish support cells back to a migratory progenitor state by pharmacologically altering the signaling environment to mimic that of the migratory primordium, with active Wnt signaling and repressed FGF signaling. The reverted supporting cells migrate anteriorly and posteriorly along the horizontal myoseptum and will re-epithelialize to form an increased number of neuromasts along the midline when the pharmacological agents are removed. These data demonstrate that supporting cells can be readily reprogrammed to a migratory multipotent progenitor state that can form new sensory neuromasts, which has important implications for our understanding of how the lateral line system matures and expands in fish and also suggest avenues for returning mammalian supporting cells back to a proliferative state.

Premature newborns with intraventricular hemorrhage do not have vasospasm pattern by cranial Doppler ultrasound: A pilot study.

Preterm neonates are at risk for neurodevelopmental impairment, especially those with intraventricular hemorrhage (IVH). Cerebral vasospasm (VSP) is a common complication after subarachnoid hemorrhage (SAH) in adult population, but it is unknown if preterm neonates with IVH may develop it. We prospectively enrolled premature newborns < 32 weeks with IVH and without IVH. All patients received serial transcranial sonography through the temporal window of the middle cerebral artery, anterior cerebral artery, posterior cerebral artery, and the internal carotid artery with transcranial Doppler sonography days 2, 4, and 10 of life. Cerebral blood velocities (CBFVs) were measured including median velocity flow (MV), peak systolic velocity (PSV), and maximum end-diastolic velocity (EDV). Resistance index and pulsatility index were calculated. VSP was defined as an increase of 50% in the baseline velocity per day and/or a Lindegaard ratio higher than 3. Fifty subjects were enrolled. None of the patients with IVH showed elevation of MV or a Lindegaard ratio > 3. There were no differences between IVH and without IVH groups regarding resistance index and pulsatility index.    Conclusion: Preterm infants with IVH do not present a pattern of VSP analyzed by Doppler transcranial ultrasound in this pilot study. What is Known: • In adult population with subarachnoid hemorrhage the most treatable cause of cerebral ischemia is due cerebral vasospasm but is unknown if premature newborn may have vasospasm due the extravasation of blood in the context of intraventricular hemorrhage What is New: •In this pilot study we did not find in premature newborn with intraventricular hemorrhage signs of vasoespam measured by transcranial color doppler ultrasound.

Model of structural equations on the perception of aspects of school life and substance consumption as predictors of problem behavior in adolescents.

Introduction: Problematic behavior and drug use are behaviors of social concern, especially in adolescence. There are school factors that can contribute to their development or prevent them. The objective was to establish explanatory models of the relationship between various school variables with the consumption of alcohol, tobacco and cannabis; determining its direct and/or indirect relationship with problematic behaviors. Materials and methods: The study was cross-sectional with a sample of 346 students (Main Age=14.81; 54% women) from secondary education. Structural Equation Model (SEM) were carried to analyze the relationship between the dimensions of the Scale of perception of aspects of school life and alcohol, tobacco and cannabis consume with the presence of Problematic Behavior. Results: Problem behavior was predicted by alcohol, tobacco and cannabis consume, and binge drinking. Different aspects of school life differentially predicted problem behavior and drug use. Sense of challenge was observed as having a reciprocal predictive relationship with problem behavior. Perception of oneself at school predicts both alcohol and tobacco use; while the value given to school predicts binge drinking. Discussion: These findings suggests that, when addressing problem behavior and drug use that affect minors in school and have repercussions on class dynamics and academic outcomes, we should not focus exclusively on these problem areas, but rather take a more integrated approach that includes modifying different school-related aspects that act as risk factors for these types of problems.

Lung ultrasound and procalcitonin, improving antibiotic management and avoiding radiation exposure in pediatric critical patients with bacterial pneumonia: a randomized clinical trial.

BACKGROUND: Pneumonia is a major public health problem with an impact on morbidity and mortality. Its management still represents a challenge. The aim was to determine whether a new diagnostic algorithm combining lung ultrasound (LUS) and procalcitonin (PCT) improved pneumonia management regarding antibiotic use, radiation exposure, and associated costs, in critically ill pediatric patients with suspected bacterial pneumonia (BP). METHODS: Randomized, blinded, comparative effectiveness clinical trial. Children < 18y with suspected BP admitted to the PICU from September 2017 to December 2019, were included. PCT was determined at admission. Patients were randomized into the experimental group (EG) and control group (CG) if LUS or chest X-ray (CXR) were done as the first image test, respectively. Patients were classified: 1.LUS/CXR not suggestive of BP and PCT < 1 ng/mL, no antibiotics were recommended; 2.LUS/CXR suggestive of BP, regardless of the PCT value, antibiotics were recommended; 3.LUS/CXR not suggestive of BP and PCT > 1 ng/mL, antibiotics were recommended. RESULTS: 194 children were enrolled, 113 (58.2%) females, median age of 134 (IQR 39-554) days. 96 randomized into EG and 98 into CG. 1. In 75/194 patients the image test was not suggestive of BP with PCT < 1 ng/ml; 29/52 in the EG and 11/23 in the CG did not receive antibiotics. 2. In 101 patients, the image was suggestive of BP; 34/34 in the EG and 57/67 in the CG received antibiotics. Statistically significant differences between groups were observed when PCT resulted < 1 ng/ml (p = 0.01). 3. In 18 patients the image test was not suggestive of BP but PCT resulted > 1 ng/ml, all of them received antibiotics. A total of 0.035 mSv radiation/patient was eluded. A reduction of 77% CXR/patient was observed. LUS did not significantly increase costs. CONCLUSIONS: Combination of LUS and PCT showed no risk of mistreating BP, avoided radiation and did not increase costs. The algorithm could be a reliable tool for improving pneumonia management. CLINICAL TRIAL REGISTRATION: NCT04217980.

Nucleolar stress caused by arginine-rich peptides triggers a ribosomopathy and accelerates aging in mice.

Nucleolar stress (NS) has been associated with age-related diseases such as cancer or neurodegeneration. To investigate how NS triggers toxicity, we used (PR)n arginine-rich peptides present in some neurodegenerative diseases as inducers of this perturbation. We here reveal that whereas (PR)n expression leads to a decrease in translation, this occurs concomitant with an accumulation of free ribosomal (r) proteins. Conversely, (PR)n-resistant cells have lower rates of r-protein synthesis, and targeting ribosome biogenesis by mTOR inhibition or MYC depletion alleviates (PR)n toxicity in vitro. In mice, systemic expression of (PR)97 drives widespread NS and accelerated aging, which is alleviated by rapamycin. Notably, the generalized accumulation of orphan r-proteins is a common outcome of chemical or genetic perturbations that induce NS. Together, our study presents a general model to explain how NS induces cellular toxicity and provides in vivo evidence supporting a role for NS as a driver of aging in mammals.

Two siblings with uncombable hair syndrome: A new pathogenic variant.

Two siblings presented with straw-colored, frizzy, and wiry hair. They had no associated abnormalities and no family history of abnormal hair. Trichoscopy showed the longitudinal groove in the hair shafts, characteristic of uncombable hair syndrome. Molecular genetic analysis revealed a new pathogenic variant (c.1374dup; p. Val459ArgfsTer15) in PADI3, not previously described.

Efficacy of the use of perfluorocarbon as a temporary tamponade agent in severe ocular trauma and/or complex retinopexy: a scoping review.

BACKGROUND: Perfluorocarbon (PFC)possesses unique chemical properties that favor the pigment epithelium's adhesion and allows the drainage of subretinal fluid through retinal holes present in retinal detachment cases. However, PFC as a temporary tamponade agent has been limited due to its high potential for toxicity. MAIN BODY: We conducted a scoping review regarding the use of PFC in vitreoretinal surgery as a temporary tamponade in subjects with severe ocular trauma or severe retinal detachment who received a therapeutic intervention (vitrectomy via posterior approach with the use of PFC as a temporary tamponade), compared to vitrectomy without the use of PFC as a temporary tamponade. Outcomes of interest were retinal reattachment, visual acuity (VA), postoperative complications and retinal toxicity. The search was performed in Medline, Medline In-Process & Other Non-Indexed Citations, Medline Daily Update, Embase databases. Reference lists from relevant review articles were also included. Two hundred thirty-eight studies were found, with no duplicate entries. In the first selection, 230 articles were eliminated; in the second selection, 6 additional articles were discarded. In total, 8 articles were obtained in this review. Two selected articles corresponded to animal studies and 6 to studies in humans. Regarding study design, 5 were case series, and 1 was a cohort study. CONCLUSION: PFC as a short-term tamponade had high rates of reapplication, improved VA, and the most frequent adverse effects were reversible after PFC withdrawal. Nonetheless, the quality of the studies was poor. Studies with more rigorous methodologies are needed to determine visual and structural outcomes and potential risks of PFC use as a temporary tamponade in vitreoretinal surgery.

Dynamic Micropatterning Reveals Substrate-Dependent Differences in the Geometric Control of Cell Polarization and Migration.

Cells are highly dynamic and adopt variable shapes and sizes. These variations are biologically important but challenging to investigate in a spatiotemporally controlled manner. Micropatterning, confining cells on microfabricated substrates with defined geometries and molecular compositions, is a powerful tool for controlling cell shape and interactions. However, conventional binary micropatterns are static and fail to address dynamic changes in cell polarity, spreading, and migration. Here, a method for dynamic micropatterning is reported, where the non-adhesive surface surrounding adhesive micropatterns is rapidly converted to support specific cell-matrix interactions while allowing simultaneous imaging of the cells. The technique is based on ultraviolet photopatterning of biotinylated polyethylene glycol-grafted poly-L-lysine, and it is simple, inexpensive, and compatible with a wide range of streptavidin-conjugated ligands. Experiments using biotinylation-based dynamic micropatterns reveal that distinct extracellular matrix ligands and bivalent integrin-clustering antibodies support different degrees of front-rear polarity in human glioblastoma cells, which correlates to altered directionality and persistence upon release and migration on fibronectin. Unexpectedly, however, neither an asymmetric cell shape nor centrosome orientation can fully predict the future direction of migration. Taken together, biotinylation-based dynamic micropatterns allow easily accessible and highly customizable control over cell morphology and motility.

Predictores del estado de salud funcional posingreso en cuidados intensivos en pacientes sépticos / Predictors of Post-Admission Functional Health Status in Intensive Care in Septic Patients

Introducción: Los pacientes críticos pediátricos son susceptibles de presentar alteraciones del flujo sanguíneo cerebral que impliquen un deterioro de su estado de salud funcional. Objetivo: Identificar factores predictores de mayor riesgo de mala evolución funcional en pacientes pediátricos críticos con sepsis. Métodos: Se realizó un estudio de cohortes retrospectivo con menores de 18 años de edad con sepsis, ingresados en la unidad de cuidados intensivos pediátricos. Se recogieron variables epidemiológicas, clínicas y del estado de salud funcional previas al ingreso, al alta y a los 6 meses. El estado de salud funcional se evaluó mediante la escala de categorías de estado global y cerebral pediátrico. Se evaluó el cambio del estado funcional entre el ingreso y a los 6 meses del alta. Se realizó un análisis univariante para comparar grupos considerando el mal pronóstico y el cambio del estado funcional y su relación con las variables. Resultados: Se incluyeron 46 pacientes. A los 6 meses del alta, cuatro (8,7 por ciento) presentaron mal pronóstico funcional y ocho (17,4 por ciento) empeoramiento funcional respecto al ingreso. No se encontraron asociaciones entre las variables predictoras y la morbilidad, aunque se observó cierta tendencia en algunas como mayor soporte inotrópico (VIS > 20: 12,5 por ciento vs. 50 por ciento, p= 0,075), extracorpóreo y de reemplazo renal (25 por ciento vs. 2,6 por ciento, p= 0,074) y estancia hospitalaria más prolongada (50 por ciento vs. 15,8 por ciento , p= 0,055). Conclusiones: El soporte en la unidad de cuidados intensivos pediátricos no fue un predictor de morbilidad funcional en la muestra(AU)

Introduction: Critically ill pediatric patients are susceptible to cerebral blood flow alterations that imply a deterioration of their functional health status. Objective: To identify predictors of a higher risk of poor functional outcome in critically ill pediatric patients with sepsis. Methods: A retrospective cohort study was conducted with children under 18 years of age with sepsis, who were admitted to the pediatric intensive care unit. Epidemiological, clinical, and functional health status variables were collected prior to admission, discharge, and after 6 months. Functional health status was assessed using the Pediatric Global State and Brain Status Category Scale. The change in performance status between admission and 6 months after discharge was assessed. A univariate analysis was performed to compare groups considering poor prognosis and change in functional status and their relationship with the variables. Results: A total of 46 patients were included. At 6 months after discharge, four (8.7 percent) had a poor functional prognosis and eight (17.4 percent) had functional worsening at admission. No associations were found between the predictor variables and morbidity, although some trends were observed in some variables, such as greater inotropic support (SIV > 20: 12.5 percent vs. 50 percent, p = 0.075), extracorporeal and renal replacement (25 percent vs. 2.6 , percent p = 0.074), and longer hospital stay (50 percent vs. 15.8 percent , p = 0.055). Conclusions: Support in the pediatric intensive care unit was not a predictor of functional morbidity in the sample(AU)

Translational control of furina by an RNA regulon is important for left-right patterning, heart morphogenesis and cardiac valve function.

Heart development is a complex process that requires asymmetric positioning of the heart, cardiac growth and valve morphogenesis. The mechanisms controlling heart morphogenesis and valve formation are not fully understood. The pro-convertase FurinA functions in heart development across vertebrates. How FurinA activity is regulated during heart development is unknown. Through computational analysis of the zebrafish transcriptome, we identified an RNA motif in a variant FurinA transcript harbouring a long 3' untranslated region (3'UTR). The alternative 3'UTR furina isoform is expressed prior to organ positioning. Somatic deletions in the furina 3'UTR lead to embryonic left-right patterning defects. Reporter localisation and RNA-binding assays show that the furina 3'UTR forms complexes with the conserved RNA-binding translational repressor, Ybx1. Conditional ybx1 mutant embryos show premature and increased Furin reporter expression, abnormal cardiac morphogenesis and looping defects. Mutant ybx1 hearts have an expanded atrioventricular canal, abnormal sino-atrial valves and retrograde blood flow from the ventricle to the atrium. This is similar to observations in humans with heart valve regurgitation. Thus, the furina 3'UTR element/Ybx1 regulon is important for translational repression of FurinA and regulation of heart development.

Risk factors and outcome of Chimeric Antigen Receptor T-Cell patients admitted to Pediatric Intensive Care Unit: CART-PICU study.

Introduction: Chimeric antigen receptor (CAR)T-cell CD19 therapy is an effective treatment for relapsed/refractory B-cell acute lymphoblastic leukemia. It can be associated with life-threatening toxicities which often require PICU admission. Purpose: to describe clinical characteristics, treatment and outcome of these patients. Methods: Prospective observational cohort study conducted in a tertiary pediatric hospital from 2016-2021. Children who received CAR-T admitted to PICU were included. We collected epidemiological, clinical characteristics, cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), treatment, length of stay and mortality. Results: CAR T-cells (4-1BB constructs) were infused in 59 patients. Twenty-four (40.7%) required PICU admission, length of stay was 4 days (IQR 3-6). Median age was 8.3 years (range 4-24). Patients admitted to PICU presented higher disease burden before infusion: 24% blasts in bone marrow (IQR 5-72) vs. 0 (0-6.9), p<0.001. No patients with <5% blasts were admitted to PICU. Main reasons for admissions were CRS (n=20, 83.3%) and ICANS (n=3, 12.5%). Fourteen patients (58.3%) required inotropic support, 14(58.3%) respiratory. Sixteen patients (66.6%) received tocilizumab, 10(41.6%) steroids, 6(25.0%) anakinra, and 5(20.8%) siltuximab. Ten patients (41.6%) presented neurotoxicity, six of them severe (ICANS 3-4). Two patients died at PICU (8.3%) because of refractory CRS-hemophagocytic lymphohistyocitosis (carHLH) syndrome. There were no significant differences in relapse rate after CAR-T in patients requiring PICU, it was more frequently CD19 negative (p=0.344). Discussion: PICU admission after CAR-T therapy was mainly due to CRS. Supportive treatment allowed effective management and high survival. Some patients presenting with carHLH, can suffer a fulminant course.

Integration of Phenotype Term Prioritization and Gene Expression Analysis Reveals a Novel Variant in the PERP Gene Associated with Autosomal Recessive Erythrokeratoderma.

Hereditary palmoplantar keratodermas (PPKs) are a clinically and genetically heterogeneous group of disorders characterized by excessive epidermal thickening of palms and soles. Several genes have been associated with PPK including PERP, a gene encoding a crucial component of desmosomes that has been associated with dominant and recessive keratoderma. We report a patient with recessive erythrokeratoderma (EK) in which whole exome sequencing (WES) prioritized by human phenotype ontology (HPO) terms revealed the presence of the novel variant c.153C > A in the N-terminal region the PERP gene. This variant is predicted to have a nonsense effect, p.(Cys51Ter), resulting in a premature stop codon. We demonstrated a marked reduction in gene expression in cultured skin fibroblasts obtained from the patient. Despite the PERP gene is expressed at low levels in fibroblasts, our finding supports a loss-of-function (LoF) mechanism for the identified variant, as previously suggested in recessive EK. Our study underscores the importance of integrating HPO analysis when using WES for molecular genetic diagnosis in a clinical setting, as it facilitates continuous updates regarding gene-clinical feature associations.

B cell receptor-induced protein dynamics and the emerging role of SUMOylation revealed by proximity proteomics.

Successful B cell activation, which is critical for high-affinity antibody production, is controlled by the B cell antigen receptor (BCR). However, we still lack a comprehensive protein-level view of the very dynamic multi-branched cellular events triggered by antigen binding. Here, we employed APEX2 proximity biotinylation to study antigen-induced changes, 5-15 min after receptor activation, at the vicinity of the plasma membrane lipid rafts, wherein BCR enriches upon activation. The data reveals dynamics of signaling proteins, as well as various players linked to the subsequent processes, such as actin cytoskeleton remodeling and endocytosis. Interestingly, our differential expression analysis identified dynamic responses in various proteins previously not linked to early B cell activation. We demonstrate active SUMOylation at the sites of BCR activation in various conditions and report its functional role in BCR signaling through the AKT and ERK1/2 axes.

Graft Survival in Liver Transplantation: An Artificial Neuronal Network Assisted Analysis of the Importance of Comorbidities.

OBJECTIVES: Liver transplant represents a widespread therapeutic option for patients with end-stage liver failure. Up to now, most of the scores describing the probability of liver graft survival have shown poor predictive performance. With this in mind, the present study seeks to analyze the predictive value of recipient comorbidities on liver graft survival within the first year. MATERIALS AND METHODS: The study included prospectively collected data from patients who received a liver transplant at our center from 2010 to 2021. A predictive model was then developed through an Artificial Neural Network that included the parameters associated with graft loss as identified by the Spanish Liver Transplant Registry report and comorbidities with prevalence >2% present in our study cohort. RESULTS: Most patients in our study were men (75.5%); mean age was 54.8 ± 9.6 years. The main cause of transplant was cirrhosis (86.7%), and 67.4% of patients had some associated comorbidities. Graft loss due to retransplant or death with dysfunction occurred in 14% of cases. Of all the variables analyzed, we found 3 comorbidities associated with graft loss (as shown by informative value and normalized informative value, respectively): antiplatelet and/or anticoagulants treatments (0.124 and 78.4%), previous immunosuppression (0.110 and 69.6%), and portal thrombosis (0.105 and 66.3%). Remarkably, our model showed a C statistic of 0.745 (95% CI, 0.692-0.798; asymptotic P < .001), which was higher than others found in previous studies. CONCLUSIONS: Our model identified key parameters that may influence graft loss, including specific recipient comorbidities. The use of artificial intelligence methods could reveal connections that may be overlooked by conventional statistics.

Children's emotional and behavioral response following a migration: a scoping review.

Background: Migration is a present and pressing global phenomenon, as climate change and political instability continue to rise, more populations will be forced to relocate. Efficient strategies must be in place to aid the transition of vulnerable populations - such as children - and strategic interventions designed based on an understanding of their particular needs and risks. Aim of the review: This article reviewed recent research regarding the mental health of migrant children identifying a wide array of common characteristics to their emotional and behavioral responses following a migration, and compiled an extensive list of protective and risk factors. 48 studies were selected from Proquest, WOS, SCOPUS, and Pubpsych published between 2015 and 2022 covering studies of children around the world. Findings: The migration-related factors that most negatively impacted children's mental health were experiences such as discrimination, loss of access to governmental and educational resources, premigration trauma, loss of community, cultural distance and acculturation, the burden on the family unit, and socioeconomic difficulties. Thus, with the right interventions and policy changes, it is possible to make migration a non-traumatic experience in order to avoid the common emergence of depressive symptoms, PTSS (post-traumatic stress symptoms), anxiety, and other mental health issues. Supporting the family unit's transition, encouraging peer connections, and directing government aid to expedite resources upon arrival will serve as protective factors for children while they integrate into their new environment.

Isolation of the B Cell Immune Synapse for Proteomic Analysis.

Recent technical developments have fueled increasing utilization of proteomics to gain new insights into various aspects of cellular behavior. In this chapter, we describe a method to specifically isolate immune synapses from mouse primary B cells. The method utilizes antibody-coated magnetic beads to induce the formation of the immune synapses and describes a protocol for the extraction of the cell-bead adhesions for mass spectrometry analysis. Finally, this method enables unveiling the large-scale protein content of the immune synapse.

The value of private properties for the conservation of biodiversity in the Brazilian Cerrado.

Areas set aside for conservation within private lands may be key to enhancing biodiversity-friendly landscapes. This conservation strategy should be especially effective in highly threatened regions that are poorly protected by public lands, such as the Brazilian Cerrado. Brazil's Native Vegetation Protection Law has included set-aside areas within private properties, but their relevance to conservation has not been evaluated. We assess whether private lands are contributing to biodiversity in the Cerrado, a global biodiversity conservation priority and major region for food production, where land use conflicts are often at odds with conservation objectives. We determined that private protected areas accommodate up to 14.5% of threatened vertebrate species ranges, which increases to 25% when considering the distribution of remaining native habitat. Moreover, the spatial spread of private protected areas benefits a large number of species. Ecological restoration of private protected lands would improve the benefits of this protection system, especially in the Southeastern Cerrado, where a large economic hub meets a threat hotspot.

An Artificial Placenta Experimental System in Sheep: Critical Issues for Successful Transition and Survival up to One Week.

OBJECTIVE: To describe the development of an artificial placenta (AP) system in sheep with learning curve and main bottlenecks to allow survival up to one week. METHODS: A total of 28 fetal sheep were transferred to an AP system at 110-115 days of gestation. The survival goal in the AP system was increased progressively in three consecutive study groups: 1-3 h (n = 8), 4-24 h (n = 10) and 48-168 h (n = 10). Duration of cannulation procedure, technical complications, pH, lactate, extracorporeal circulation (EC) circuit flows, fetal heart rate, and outcomes across experiments were compared. RESULTS: There was a progressive reduction in cannulation complications (75%, 50% and 0%, p = 0.004), improvement in initial pH (7.20 ± 0.06, 7.31 ± 0.04 and 7.33 ± 0.02, p = 0.161), and increment in the rate of experiments reaching survival goal (25%, 70% and 80%, p = 0.045). In the first two groups, cannulation accidents, air bubbles in the extracorporeal circuit, and thrombotic complications were the most common cause of AP system failure. CONCLUSIONS: Achieving a reproducible experimental setting for an AP system is extremely challenging, time- and effort-consuming, and requires a highly multidisciplinary team. As a result of the learning curve, we achieved reproducible transition and survival up to 7 days. Extended survival requires improving instrumentation with custom-designed devices.