Journal of Medical Internet Research - International Scientific Journal for Medical Research, Information and Communication on the Internet #Preprint #PeerReviewMe: Warning: This is a unreviewed preprint. Readers are warned that the document has not been peer-reviewed by expert/patient reviewers or an academic editor, may contain misleading claims, and is likely to undergo changes before final publication, if accepted, or may have been rejected/withdrawn. Readers with interest and expertise are encouraged to sign up as peer-reviewer, if the paper is within an open peer-review period. Please cite this preprint only for review purposes or for grant applications and CVs (if you are the author). Background: The use of the internet as a source of information has grown exponentially in the last decade. YouTube is currently the second most visited website and a major online educational resource for medical students. Objective: The aim of this study was to evaluate the quality, accuracy and attractiveness of the information acquired from YouTube videos about two central concepts in immunology. Methods: YouTube videos posted prior to August 27, 2018 were searched using selected keywords related to either antigen presentation or immunoglobulin gene rearrangement. Video characteristics were recorded and the Video Power Index was calculated. Videos were assessed using five validated scoring systems: Understandability and Attractiveness, reliability, Content and Comprehensiveness, Global Quality Score and a subjective score. Videos were categorized by educational usefulness and by source. Results: A total of 82 videos about antigen presentation and 70 about immunoglobulin gene rearrangement were analyzed. Videos had a mean Understandability and Attractiveness score of 6,57/8 and 5,84/8, Content and Comprehensiveness score of 9,84/20 and 5,84/20, reliability score of 1,65/4 and 1,53/4, Global Quality Scale of 3,38/5 and 2,76/5, and subjective score of 2,00/3 and 2,00/3, respectively. The organized channels group tended to have the highest Video Power Index and Global Quality Scale. Conclusions: YouTube can provide medical students with some useful information about immunology, although content-wise it cannot substitute textbooks and academic courses. Students and teachers should be aware of the educational quality of available videos if they intend to use them in the context of blended learning.

Bronchopulmonary dysplasia (BPD) is caused by preterm neonatal lung injury and results in oxygen dependency and pulmonary hypertension. Current clinical management fails to reduce the incidence of BPD, which calls for novel therapies. Fetal rabbits have a lung development that mimics humans and can be used as a translational model to test novel treatment options. In preterm rabbits, exposure to hyperoxia leads to parenchymal changes, yet vascular damage has not been studied in this model. In this study we document the early functional and structural changes of the lung vasculature in preterm rabbits that are induced by hyperoxia after birth. Pulmonary artery Doppler measurements, micro-CT barium angiograms and media thickness of peripheral pulmonary arteries were affected after seven days of hyperoxia when compared to controls. The parenchyma was also affected both at the functional and structural level. Lung function testing showed higher tissue resistance and elastance, with a decreased lung compliance and lung capacity. Histologically hyperoxia leads to fewer and larger alveoli with thicker walls, less developed distal airways and more inflammation than normoxia. In conclusion, we show that the rabbit model develops pulmonary hypertension and developmental lung arrest after preterm lung injury, which parallel the early changes in human BPD. Thus it enables the testing of pharmaceutical agents that target the cardiovascular compartment of the lung for further translation towards the clinic.

Mesenchymal stem cells derived from human amniotic fluid (hAFSCs) are a promising source for cellular therapy, especially for renal disorders, as a subpopulation is derived from the fetal urinary tract. The purpose of this study was to evaluate if hAFSCs with a renal progenitor phenotype demonstrate a nephroprotective effect in acute ischemia reperfusion (I/R) model and prevent late stage fibrosis. A total of 45 male 12-wk-old Wistar rats were divided into three equal groups;: rats subjected to I/R injury and treated with Chang Medium, rats subjected to I/R injury and treated with hAFSCs and sham-operated animals. In the first part of this study, hAFSCs that highly expressed CD24, CD117, SIX2 and PAX2 were isolated and characterized. In the second part, renal I/R injury was induced in male rats and cellular treatment was performed 6 hours later via arterial injection. Functional and histological analyses were performed 24 hours, 48 hours and 2 months after treatment using serum creatinine, urine protein to creatinine ratio, inflammatory and regeneration markers and histomorphometric analysis of the kidney. Statistical analysis was performed by analysis of variance followed by the Tukey’s test for multiple comparisons or by nonparametric Kruskal-Wallis followed by Dunn. Statistical significance level was defined as p <0.05. hAFSCs treatment resulted in significantly reduced serum creatinine level at 24 hours, less tubular necrosis, less hyaline cast formation, higher proliferation index, less inflammatory cell infiltration and less myofibroblasts at 48h. The treated group had less fibrosis and proteinuria at 2 months after injury. hAFSCs contain a renal progenitor cell subpopulation that has a nephroprotective effect when delivered intra-arterially in rats with renal I/R injury, and reduces interstitial fibrosis on long term follow-up.

Background: As pediatric ambulatory surgeries are rising and existing methods to reduce perioperative anxiety and pain are lacking in this population, a serious game for health (SGH), CliniPup, was developed to address this unmet need. CliniPup was generated using the SERES framework for serious game development. Objective: The goal of the research was to clinically evaluate CliniPup as an adjunct therapy to existing pharmacological interventions aimed at reducing perioperative anxiety and pain in children undergoing ambulatory surgery. Methods: CliniPup was evaluated in a prospective randomized controlled pilot trial in 20 children aged 6 to 10 years who underwent elective surgery and their parents. Study participants were randomly assigned to the test (n=12) or control group (n=8). Children in the test group played CliniPup 2 days prior to surgery, and children in the control group received standard of care. On the day of surgery, pediatric anxiety was measured with the modified Yale Preoperative Anxiety Scale and parental anxiety was assessed with the State-Trait Anxiety Inventory. Pediatric postoperative pain was assessed by the Wong-Baker Faces Pain Rating Scale. Child and parent user experience and satisfaction were also evaluated in the test group using structured questionnaires. Results: Despite the small sample, preoperative anxiety scores were significantly lower (P=.01) in children who played CliniPup prior to surgery compared to controls. Parental preoperative anxiety scores were also lower in the test group (P=.10) but did not reach significance. No significant differences were observed in postoperative pain scores between groups (P=.54). The evaluation of user experience and satisfaction revealed that both children and parents were satisfied with CliniPup and would recommend the game to peers. Conclusions: Results of the pilot trial introduce CliniPup as a potentially effective and attractive adjunct therapy to reduce preoperative anxiety in children undergoing ambulatory surgery with a trend toward positive impact on parental preoperative anxiety. These results support the use of the SERES framework to generate an evidence-based SGH that results in positive health outcomes for patients. Based on these preliminary findings, we propose a research agenda to further develop and investigate this tool. Trial Registration: ClinicalTrials.gov NCT03874442; https://clinicaltrials.gov/ct2/show/NCT03874442 (Archived by WebCite at http://www.webcitation.org/78KZab8qc)

Accurate fluid pressure in the fetal lung is critical for its development, especially at the beginning of the saccular stage when alveolar epithelial type 1 (AT1) and type 2 (AT2) cells differentiate from the epithelial progenitors. Despite our growing understanding of the role of physical forces in lung development, the molecular mechanisms that regulate the transduction of mechanical stretch to alveolar differentiation remain elusive. To simulate lung distension, we optimized both an ex vivo model with precision cut lung slices and an in vivo model of fetal tracheal occlusion. Increased mechanical tension showed to improve alveolar maturation and differentiation toward AT1. By manipulating ROCK pathway, we demonstrate that stretch-induced Yap/Taz activation promotes alveolar differentiation toward AT1 phenotype via ROCK activity. Our findings show that balanced ROCK-Yap/Taz signaling is essential to regulate AT1 differentiation in response to mechanical stretching of the fetal lung, which might be helpful in improving lung development and regeneration.

Objective: To evaluate if the up-regulation of vascular endothelial growth factor strengthens the protective effect of amniotic fluid stem cells in a renal ischemia-reperfusion injury model. Design: Randomized animal study. Settings: University research laboratory. Subjects: A total of 40 males 12-week-old Wistar rats were subjected to ischemia-reperfusion and assigned to four groups: amniotic fluid stem cells, vascular endothelial growth factor-amniotic fluid stem cells in two different doses, and vehicle. Ten animals were used as sham-controls. Intervention: Six hours after induction of renal ischemia-reperfusion injury, amniotic fluid stem cells, vascular endothelial growth factor-amniotic fluid stem cells in two different doses, or vehicle were injected intraarterially. Measurements and Main Results: Analyses were performed at 24 hours, 48 hours, and 2 months after treatment. Outcome measures included serum creatinine, urine microprotenuira, and immunohistomorphometric analyses. Vascular endothelial growth factor-amniotic fluid stem cells induced a significantly higher nephroprotection than amniotic fluid stem cells. This effect was mediated mainly by immunomodulation, which led to lower macrophage infiltration and higher presence of regulatory T cell after ischemia-reperfusion injury. At medium term, it inhibited the progression toward chronic kidney disease. Vascular endothelial growth factor-amniotic fluid stem cells can worsen the ischemia-reperfusion injury when delivered in a high dose. Conclusions: Up-regulation of vascular endothelial growth factor enhances the therapeutic effect of human amniotic fluid stem cells in rats with renal ischemia-reperfusion injury, mainly by mitogenic, angiogenic, and anti-inflammatory mechanisms.