Vanessa Lavallard

Background Because of COVID-19, the 2020 written medical examinations were replaced by mandatory formative online assessments. This study aimed to determine students’ performance, self-assessment of performance, and perception about the switch from a summative to a formative approach. Methods Medical students from year 2 to 5 (n=648) were included. They could repeat each test once or twice. They rated their performance after each attempt and were then given their score. Detailed feedback was given at the end of the session. An online survey determined medical students’ perception about the reorganization of education. Two items concerned the switch from summative to formative assessments Results Formative assessments involved 2385 examinees totaling 3197 attempts. Among examinees, 30.8% made at least 2 attempts. Scores increased significantly at the second attempt (median 9.4, IQR 10.8), and duration decreased (median -31.0, IQR 48.0). More than half of examinees (54.6%) underestimated their score, female students more often than male. Low performers overestimated, while high performers underestimated their scores. Students approved of the switch to formative assessments. Stress was lessened but motivation for learning decreased. Conclusions Medical students’ better scores at a second attempt support a benefit of detailed feedback, learning time and re-test opportunity on performance. Decreased learning motivation and a minority of students repeating the formative assessments point to the positive influence of summative assessment on learning.

Background: Because of COVID-19, the 2020 written medical examinations were replaced by mandatory formative online assessments. This study aimed to determine students’ performance, self-assessment of performance, and perception about the switch from a summative to a formative approach. Methods: Medical students from year 2 to 5 (n=648) were included. They could repeat each test once or twice. They rated their performance after each attempt and were then given their score. Detailed feedback was given at the end of the session. An online survey determined medical students’ perception about the reorganization of education. Two items concerned the switch from summative to formative assessments Results: Formative assessments involved 2385 examinees totaling 3197 attempts. Among examinees, 30.8% made at least 2 attempts. Scores increased significantly at the second attempt (median 9.4, IQR 10.8), and duration decreased (median -31.0, IQR 48.0). More than half of examinees (54.6%) underestimated their score, female students more often than male. Low performers overestimated, while high performers underestimated their scores. Students approved of the switch to formative assessments. Stress was lessened but motivation for learning decreased. Conclusions: Medical students’ better scores at a second attempt support a benefit of detailed feedback, learning time and re-test opportunity on performance. Decreased learning motivation and a minority of students repeating the formative assessments point to the positive influence of summative assessment on learning.

Background: Because of COVID-19, the 2020 written medical examinations were replaced by mandatory formative online assessments. This study aimed to determine students’ performance, self-assessment of performance, and perception about the switch from a summative to a formative approach. Methods: Medical students from year 2 to 5 (n=648) were included. They could repeat each test once or twice. They rated their performance after each attempt and were then given their score. Detailed feedback was given at the end of the session. An online survey determined medical students’ perception about the reorganization of education. Two items concerned the switch from summative to formative assessments Results: Formative assessments involved 2385 examinees totaling 3197 attempts. Among examinees, 30.8% made at least 2 attempts. Scores increased significantly at the second attempt (median 9.4, IQR 10.8), and duration decreased (median -31.0, IQR 48.0). More than half of examinees (54.6%) underestimated their score, female students more often than male. Low performers overestimated, while high performers underestimated their scores. Students approved of the switch to formative assessments. Stress was lessened but motivation for learning decreased. Conclusions: Medical students’ better scores at a second attempt support a benefit of detailed feedback, learning time and re-test opportunity on performance. Decreased learning motivation and a minority of students repeating the formative assessments point to the positive influence of summative assessment on learning.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Hypoxia, IL-1β production and oxidative stress are involved in islet graft dysfunction and destruction. However, the link between these events has not yet been determined in transplanted islets. The goal of this study was to determine whether NLRP3 inflammasome is responsible for IL-1β production and if it is activated by hypoxia-induced oxidative stress in transplanted islets. Rat islets were transplanted under the kidney capsule of immunodeficient mice. At different times post-transplantation, blood samples were collected and islet grafts harvested. Rat islets were also incubated in vitro either under normoxia or hypoxia for 24 h, in the absence or presence of inhibitors of NLRP3 inflammasome (CASP1 inhibitor) or oxidative stress (NAC). NLRP3, CASP1, IL1B, BBC3 pro-apoptotic and BCL2 anti-apoptotic genes in transplanted and in vitro incubated islets were then studied using real time PCR. IL-1β released in the blood and in the supernatant was quantified by ELISA. Cell death was analysed by propidium iodide and Annexin-V staining. NLRP3, CASP1 and BBC3 in transplanted rat islets and IL-1β in blood transiently increased during the first days after transplantation. In islets incubated under hypoxia, NRLP3, IL1B and CASP1 and IL-1β released in supernatant increased compared to islets incubated under normoxia. These effects were prevented by the inhibition of NLRP3 inflammasome by CASP1 or oxidative stress by NAC. However, these inhibitors did not prevent hypoxia-induced rat islet death. These data show that NLRP3 inflammasome in rat islets is transiently activated after their transplantation and induced through oxidative stress in vitro. However, NRLP3 inflammasome inhibition does not protect islet cells against hypoxia.

Intraportal islet transplantation is plagued by an acute destruction of transplanted islets. Amongst the first responders, NK cells and macrophages harbor an activating receptor, NKG2D, recognizing ligands expressed by stressed cells. We aimed to determine whether islet NKG2D ligand expression increases with culture time, and to analyze the impact of antibody‐induced NKG2D blockade in islet transplantation. NKG2D‐ligand expression was analyzed in rat and human islets. Syngeneic marginal mass intraportal islet transplantations were performed in rats: control group, recipients transplanted with NKG2D‐recombinant‐treated islets (recombinant group), and recipients treated with a mouse anti‐rat anti‐NKG2D antibody and transplanted with recombinant‐treated islets (antibody‐recombinant group). Islets demonstrated increased gene expression of NKG2D ligands with culture time. Blockade of NKG2D on NK cells decreased in vitro cytotoxicity against islets. Recipients from the control and recombinant groups showed similar metabolic results; conversely, treatment with the antibody resulted in lower diabetes reversal. The antibody depleted circulating and liver NK cells in recipients, who displayed increased macrophage infiltration of recipient origin around the transplanted islets. In vitro blockade of NKG2D ligands had no impact on early graft function. Systemic treatment of recipients with an anti‐NKG2D antibody was deleterious to the islet graft, possibly through an antibody‐dependent cell‐mediated cytotoxicity reaction.

Maintaining long-term euglycemia after intraportal islet transplantation is hampered by the considerable islet loss in the peri-transplant period attributed to inflammation, ischemia and poor angiogenesis. Here, we show that viable and functional islet organoids can be successfully generated from dissociated islet cells (ICs) and human amniotic epithelial cells (hAECs). Incorporation of hAECs into islet organoids markedly enhances engraftment, viability and graft function in a mouse type 1 diabetes model. Our results demonstrate that the integration of hAECs into islet cell organoids has great potential in the development of cell-based therapies for type 1 diabetes. Engineering of functional mini-organs using this strategy will allow the exploration of more favorable implantation sites, and can be expanded to unlimited (stem-cell-derived or xenogeneic) sources of insulin-producing cells.

Remote ischemic preconditioning (RIPC), which is the intermittent interruption of blood flow to a site distant from the target organ, is known to improve solid organ resistance to ischemia‐reperfusion injury. This procedure could be of interest in islet transplantation to mitigate hypoxia‐related loss of islet mass after isolation and transplantation. Islets isolated from control or RIPC donors were analyzed for yield, metabolic activity, gene expression and high mobility group box‐1 (HMGB1) content. Syngeneic marginal mass transplantation was performed in four streptozotocin‐induced diabetic groups: control, RIPC in donor only, RIPC in recipient only, and RIPC in donor and recipient. Islets isolated from RIPC donors had an increased retrieval of 20% after 24 hours of culture compared to control donors (p=0.007), linked to less cell death (p=0.08), decreased expression of hypoxia‐related genes (Hif1a p=0.04; IRP94 p=0.008), and increased intra‐cellular (p=0.04) and nuclear HMGB1. The use of RIPC in recipients only never allowed for reversal of diabetes, with increased serum HMGB1 at day 1; the three other groups demonstrated significantly better outcomes. Performing RIPC in the donors increases islet retrieval and resistance to hypoxia. Validation is needed, but this strategy could help to decrease the number of donors per islet recipient.