Innovative microcosm experiments for the evaluation of the regeneration rates of nutrients in sediments of a hypersaline lagoon.

The aim of this study was to evaluate the regeneration of nutrients from the sediments to the water column in varying salinities, with an innovative experiment that closely simulates real environment. In vitro experiments were carried out simulating six scenarios with two sediment types (low carbonate and high carbonate). Local water and sediments were added to microcosms where circulation was forced. Results showed nitrogen release from low carbonate sediment in the lagoon, mixed and seawater (1.69, 4.68 and 7.36 µmol m-2 day-1, respectively). Phosphate diffusive fluxes were positive in lagoon water and low carbonate sediment (2.24 µmol m-2 day-1), negative with mixed water (-0.30 µmol m-2 day-1) and seawater (-0.51 µmol m-2 day-1). A phosphate release surge was observed in the low-carbonate sediment with overlying mixed water and seawater that, in the natural environment, may boost primary production.

Technical aspects and outcomes of living donor liver transplantation for pediatric patients with situs inversus.

The vascular anomalies encountered in patients with biliary atresia associated with polysplenia syndrome and situs inversus (SI) demand technical refinements when liver transplantation is being performed. The available data describing the technique used in living donor liver transplantation (LDLT) in this population are limited; the short vascular stumps of the donor's liver can impart additional technical difficulties during vascular reconstruction. Here we describe our experience with 9 children with biliary atresia and SI who underwent LDLT. In our series, the retrohepatic vena cava was absent for 7 patients, 7 had a preduodenal portal vein (PV), and 4 had a variant arterial anatomy. The donor's left hepatic vein was anastomosed to the confluence of the recipient's 3 hepatic veins in 7 patients. Vascular grafts were used for PV reconstruction in 3 cases. A left lateral segment graft was used in all but 1 patient who needed a graft reduction. All grafts were placed in the upper left abdomen. There were no vascular complications after transplantation. All patients were alive and well at a median follow-up of 55 months. In conclusion, LDLT can be successfully performed in pediatric patients with SI. Complex vascular anomalies associated with the use of partial liver grafts obtained from living donors are not associated with an increased occurrence of vascular complications.