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Background: Pediatric Crohn's disease is characterized by a higher incidence of complicated phenotypes. Murine models help to better understand the dynamic process of intestinal fibrosis and test therapeutic interventions. Pre-pubertal models are lacking. We aimed to adapt a model of chronic colitis to pre-pubertal rats and test if a polymeric diet rich in TGF-β2 could reduce TNBS-induced intestinal inflammation and fibrosis., Methods: Colitis was induced in 20 five-week-old Sprague-Dawley male rats by weekly rectal injections of increasing doses of TNBS (90 mg/kg, 140 mg/kg and 180 mg/kg) for 3 weeks, while 10 controls received phosphate-buffered saline. Rats were anesthetized using ketamine and chlorpromazine. After first administration of TNBS, 10 rats were fed exclusively MODULEN IBD® powder, while remaining rats were fed breeding chow. Colitis was assessed one week after last dose of TNBS by histopathology and magnetic resonance colonography (MRC)., Results: Histological inflammation and fibrosis scores were higher in TNBS group than controls (p < 0.05 for both). MRC showed increased colon wall thickness in TNBS group compared to controls (p < 0.01), and increased prevalence of strictures and target sign (p < 0.05). Colon expression of COL1A1, CTGF, α-SMA and COX-2 did not differ between TNBS rats and controls. TNBS colitis was not associated with growth failure. Treatment with MODULEN IBD® was associated with growth failure, increased colon weight/length ratio (p < 0.01), but did not affect histological scores or MRI characteristics. Colon expression of α-SMA was significantly lower in the MODULEN group versus controls (p = 0.005)., Conclusion: Features of chronic colitis were confirmed in this model, based on MRC and histopathology. Treatment with MODULEN did not reverse inflammation or fibrosis.

Introduction: Li-Fraumeni syndrome (LFS), due to TP53 germline mutations, is characterised by a remarkably high incidence of multiple primary cancers (MPCs), and the key role of p53 in response to DNA damage questions the contribution of anticancer treatments to MPCs development., Materials and Methods: We first evaluated genotoxicity of X-rays and different classes of conventional chemotherapies, thanks to genotoxicity assays, based on the measurement of transcriptional response to DNA damage and performed in murine splenocytes, either exposed ex vivo or extracted from exposed mice. We then exposed a total of 208 Trp53Δ/Δ, wt/Δ or wt/wt mice to clinical doses of X-rays or genotoxic or non-genotoxic chemotherapies. Tumour development was monitored using whole-body magnetic resonance imaging and pathological examination at death., Results: X-rays and conventional chemotherapies, except mitotic spindle poisons, were found to be genotoxic in both p53 genotoxicity assays. Exposition to X-rays and the topoisomerase inhibitor etoposide, analysed as genotoxic anticancer treatment, drastically increase the tumour development risk in Trp53Δ/Δ and wt/Δ mice (hazard ration [HR] = 4.4, 95% confidence interval [CI] [2.2-8.8], p < 0.001*** and HR = 4.7, 95% CI [2.4-9.3], p < 0.001***, respectively). In contrast, exposure to the non-genotoxic mitotic spindle poison, docetaxel, had no impact on tumour development., Conclusions: This study shows that radiotherapy and genotoxic chemotherapies significantly increase the risk of tumour development in a LFS mice model. These results strongly support the contribution of genotoxic anticancer treatments to MPC development in LFS patients. Therefore, to reduce the risk of MPCs in germline TP53 mutation carriers, radiotherapy should be avoided whenever possible, surgical treatment prioritised, and non-genotoxic treatments considered., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Acanthamoeba keratitis (AK) is a sight-threatening infectious disease. Its effective and safe medical therapy remains highly debated. Recently, voriconazole, a monotriazole with noted in vitro activity against a large variety of fungi, has been successfully used both topically and systemically to treat human AK cases., Objectives: To measure anti-Acanthamoeba polyphaga in vitro activity, anti-rat AK efficiency and rat cornea penetration of eye-drop and oral voriconazole., Methods: A. polyphaga was maintained in axenic cultures. In vitro, amoebicidal and cysticidal activities of voriconazole were measured using an XTT assay. AK lesions of Sprague Dawley rats were scored from grade 0 to grade 3. For 21 days, from day 7 post-infection, voriconazole (1% solution) eye drops were instilled or voriconazole was administered by gavage (60 mg/kg/day). After killing, superficial corneal epithelium scrapings were cultured and analysed by PCR, and eye-globe histology was performed. Cornea and plasma concentrations were determined using 2D HPLC separation and tandem MS., Results: In vitro, voriconazole inhibited trophozoite proliferation with an IC50 value of 0.02 mg/L and an IC90 value of 2.86 mg/L; no cysticidal effect was found. In AK rats, eye drops reduced clinical worsening from day 7 to day 14 post-infection and oral voriconazole was not effective. Voriconazole cornea concentrations were directly dependent on the frequency of eye-drop instillations, which resulted in lower plasma concentrations, whilst oral voriconazole resulted in lower cornea concentrations., Conclusions: Present data underline the need for high-frequency eye-drop instillation regimens for efficient AK therapy.

Choriocarcinoma is a highly malignant neoplasm resulting from the malignant transformation of proliferating trophoblastic cells and the molecular mechanisms leading to this transformation remain to be characterized. We report here the first case of a female germline TP53 mutation carrier who developed, as a first tumour, a lung choriocarcinoma, 6 months after a normal delivery. Molecular analyses established the gestational origin of the choriocarcinoma and showed, within the tumour, the presence of the germline mutant TP53 allele and loss of the wild-type allele. Resistance to methotrexate chemotherapy led to perform a surgical resection of the tumour. In agreement with the permissive role of TP53 mutations to oncogenic events, this report strongly suggests that TP53 mutations may promote malignant transformation of proliferating trophoblastic cells. Therefore, female TP53 mutation carriers may have an increased risk of developing gestational choriocarcinoma and might benefit from β-hCG level monitoring after pregnancy.

Irritable bowel syndrome (IBS) is the most frequent functional gastrointestinal disorder. It is characterized by abdominal hypersensitivity, leading to discomfort and pain, as well as altered bowel habits. While it is common for IBS to develop following the resolution of infectious gastroenteritis [then termed postinfectious IBS (PI-IBS)], the mechanisms remain incompletely understood. Giardia duodenalis is a cosmopolitan water-borne enteropathogen that causes intestinal malabsorption, diarrhea, and postinfectious complications. Cause-and-effect studies using a human enteropathogen to help investigate the mechanisms of PI-IBS are sorely lacking. In an attempt to establish causality between giardiasis and postinfectious visceral hypersensitivity, this study describes a new model of PI-IBS in neonatal rats infected with G. duodenalis At 50 days postinfection with G. duodenalis (assemblage A or B), long after the parasite was cleared, rats developed visceral hypersensitivity to luminal balloon distension in the jejunum and rectum, activation of the nociceptive signaling pathway (increased c-fos expression), histological modifications (villus atrophy and crypt hyperplasia), and proliferation of mucosal intraepithelial lymphocytes and mast cells in the jejunum, but not in the rectum. G. duodenalis infection also disrupted the intestinal barrier, in vivo and in vitro, which in turn promoted the translocation of commensal bacteria. Giardia-induced bacterial paracellular translocation in vitro correlated with degradation of the tight junction proteins occludin and claudin-4. The extensive observations associated with gut hypersensitivity described here demonstrate that, indeed, in this new model of postgiardiasis IBS, alterations to the gut mucosa and c-fos are consistent with those associated with PI-IBS and, hence, offer avenues for new mechanistic research in the field., (Copyright © 2016 the American Physiological Society.)