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Abstract Background Stromal vascular fraction (SVF) treatment promoted the regeneration of the intestinal epithelium, limiting lethality in a mouse model of radiation-induced gastrointestinal syndrome (GIS). The SVF has a heterogeneous cell composition; the effects between SVF and the host intestinal immunity are still unknown. The specific role of the different cells contained in the SVF needs to be clarified. Monocytes–macrophages have a crucial role in repair and monocyte recruitment and activation are orchestrated by the chemokine receptors CX3CR1 and CCR2. Methods Mice exposed to abdominal radiation (18 Gy) received a single intravenous injection of SVF (2.5 × 106 cells), obtained by enzymatic digestion of inguinal fat tissue, on the day of irradiation. Intestinal immunity and regeneration were evaluated by flow cytometry, RT-PCR and histological analyses. Results Using flow cytometry, we showed that SVF treatment modulated intestinal monocyte differentiation at 7 days post-irradiation by very early increasing the CD11b+Ly6C+CCR2+ population in the intestine ileal mucosa and accelerating the phenotype modification to acquire CX3CR1 in order to finally restore the F4/80+CX3CR1+ macrophage population. In CX3CR1-depleted mice, SVF treatment fails to mature the Ly6C−MCHII+CX3CR1+ population, leading to a macrophage population deficit associated with proinflammatory environment maintenance and defective intestinal repair; this impaired SVF efficiency on survival. Consistent with a CD11b+ being involved in SVF-induced intestinal repair, we showed that SVF-depleted CD11b+ treatment impaired F4/80+CX3CR1+macrophage pool restoration and caused loss of anti-inflammatory properties, abrogating stem cell compartment repair and survival. Conclusions These data showed that SVF treatment mitigates the GIS-involving immunomodulatory effect. Cooperation between the monocyte in SVF and the host monocyte defining the therapeutic properties of the SVF is necessary to guarantee the effective action of the SVF on the GIS.

Abstract Background The evaluation process of French medical students will evolve in the next few years in order to improve assessment validity. Script concordance testing (SCT) offers the possibility to assess medical knowledge alongside clinical reasoning under conditions of uncertainty. In this study, we aimed at comparing the SCT scores of a large cohort of undergraduate medical students, according to the experience level of the reference panel. Methods In 2019, the authors developed a 30-item SCT and sent it to experts with varying levels of experience. Data analysis included score comparisons with paired Wilcoxon rank sum tests and concordance analysis with Bland & Altman plots. Results A panel of 75 experts was divided into three groups: 31 residents, 21 non-experienced physicians (NEP) and 23 experienced physicians (EP). Among each group, random samples of N = 20, 15 and 10 were selected. A total of 985 students from nine different medical schools participated in the SCT examination. No matter the size of the panel (N = 20, 15 or 10), students’ SCT scores were lower with the NEP group when compared to the resident panel (median score 67.1 vs 69.1, p