Gut-Barrier Disruption After Laparoscopic Versus Open Major Liver Resection in the Rat.

BACKGROUND: Major liver resection may compromise gut-barrier function, increasing the risk of postoperative infectious complications. The aim of the present experimental study was to compare the effect of the laparoscopic versus the open technique for major liver resection on integrity as well as inflammatory and immune responses of the gut barrier. METHODS: Wistar rats were subjected to open 70% hepatectomy (group H), laparoscopic 70% hepatectomy (group LH), sham operation (group S) or no intervention (group C). At various timepoints (1 hour-1 week) after operation, ileal tissue was excised for oxidative state assessment (TBARS levels), histopathologic examination, histomorphometric analysis, immunohistochemical assessment of the mitotic and apoptotic activity, and tissue expression of inflammatory (interleukin-6, tumor necrosis factor-α, nuclear factor-κB and vascular cell adhesion molecule-1) and immune response biomarkers (CD4+ and CD8+ T-lymphocytes) of the intestinal mucosa. RESULTS: No changes were noted in oxidative state. The histopathologic profile was less deteriorated in group LH compared to group H. Intestinal mucosa atrophy was less intense in group LH compared to group H and was related to an equally compromised crypt cell mitotic activity. Tissue overexpression of interleukin-6, tumor necrosis factor-α, nuclear factor-κΒ, vascular cell adhesion molecule-1, CD4+, and CD8+ T-lymphocytes was less pronounced in group LH compared to group H. CONCLUSION: The employment of the laparoscopic technique for major liver resection in the rat attenuated disruption of the gut barrier compared to the open procedure. This was related to less pronounced inflammatory and immune responses of the intestinal mucosa.

Magnetic resonance imaging for early pregnancy diagnosis in the laboratory rat.

Pregnancy diagnosis and embryo counting are important end points in reproductive, developmental biology and toxicology studies. The purpose of the present study was to assess the feasibility and efficacy of magnetic resonance imaging (MRI) for early pregnancy diagnosis and embryo counting in the laboratory rat. Female Wistar rats were subjected to whole-body MRI scanning using a 1.5T MRI scanner, employing a isotropic T2-weighted 3D short-tau inversion recovery sequence from day 8 to day 12 post coitum (pc) or without prior mating, under general anaesthesia for pregnancy diagnosis and embryo counting. MRI examination was followed by laparotomy and visual inspection of the uterus to verify MRI findings. By day 8 pc, uterine bulges, characteristic of pregnancy, were depicted as oval-shaped structures of high intensity signal. By day 10 pc, embryonic vesicles were detected at the medial side of the uterine bulges. Pregnancy was diagnosed with 0% false-negative diagnosis and 100% accuracy by day 11 pc, while embryos were counted with 100% accuracy by day 12 pc. In conclusion, MRI proved to be a feasible and reliable non-invasive imaging method of early pregnancy diagnosis and embryo counting in the laboratory rat.