Effects of extensive mobilization and tension anastomosis in anorectal reconstruction (experimental study).

PURPOSE: Anorectoplasty and pull-through procedure can be performed with extensive mobilization or tension anastomosis, which can compromise bowel blood perfusion. We aimed to analyze the hypoxia biomarker values and histopathological findings in both conditions to correlate the occurrence of anal stenosis and defecation disorders in experimental models. METHODS: We created anorectal reconstruction models with impaired vascularization of the anorectum (group I) and tension anastomosis (group II) in rats. A third group of animals underwent sham operation (group III) and another as controls (group IV). Hypoxia biomarker values were assessed in all groups. The histopathological changes on the postoperative days 3 and 35, anal stenosis and defecation disorders on day 35 were compared. RESULTS: Hypoxia biomarker values confirmed postoperative ischemia in groups I-III compared to control. Group I and II rats had a similarly pronounced ischemia with histopathologic changes in the anorectum on the postoperative day 3 and accompanied by severe fibrosis on day 35. Compared to the sham operation, both groups showed defecation disorders with significant anal stenoses. CONCLUSION: Extensive rectal mobilization to about the same extent as tension anastomosis has a major impact on postoperative rectal ischemia, resulting in severe fibrotic changes in the anorectum and defecation disorders in the long term.

Novel oral anti-influenza prodrug candidate AV5075S.

OBJECTIVES: Development of a novel drug candidate with improved activity against influenza virus neuraminidase (NA) compared with currently available therapeutics. METHODS: Synthesized compounds were evaluated in vitro and in vivo. Three-dimensional molecular docking was successfully applied to classify compounds within the series by inhibitory potency. Stability was investigated in blood samples and in animal models. A pharmacokinetic study was performed in dogs and rats using peroral and intravenous administration. RESULTS: A novel highly potent drug candidate [(3R,4R,5S)-4-(2,2-difluoroacetylamino)-5-amino-3-(1-ethyl-propoxy)-cyclohex-1-enecarboxylic acid; AV5027] and its prodrug ethyl ester (AV5075S) were synthesized and tested. AV5027 and AV5075S exhibit picomolar activity against influenza virus NA. AV5075S inhibited NA in a model of pneumonia using mouse-adapted A/Aichi/2/68 (H3N2) virus significantly more strongly than oseltamivir phosphate. A general metabolic pathway was constructed for the parent compound based on experimental results and theoretical analyses. CONCLUSIONS: AV5075S can be reasonably regarded as a novel 'next in class' oral drug candidate for the treatment of influenza.