LONG-TERM DUAL PERFUSION OF ISOLATED HUMAN PLACENTAL LOBULES WITH IMPROVED OXYGENATION FOR INFECTIOUS-DISEASES RESEARCH

An improved method for long-term perfusion of the isolated human term placental lobule has been developed to investigate the maternofetal tr ansfer of infectious agents, in particular the human immunodeficiency virus (HIV). The purpose of this paper is to describe those modificati ons that allow for substantially prolonged perfusions in a biohazard e nvironment. The method described has been adapted from previous models . The perfusion apparatus has been modified for use within a biohazard hood, and, intravenous bags contain the medium for circulation of per fusates in closed circuits. A Mera Silox-S 0.3 membrane oxygenator del ivers more oxygen to the tissue, and, Electromedic Cardioplegia heat e xchangers warm the perfusate prior to oxygenation. Viability criteria (glucose consumption, lactate production, de nova production of human placental lactogen (hPL), volume loss, flow, temperature, pressure, ox ygen transfer, carbon dioxide production, absence of IgM transfer and light and electron microscopy) demonstrate that the placental tissue r emains in a functional state throughout the perfusion. Oxygen and gluc ose consumption are bath stable over time; lactate levels remain const ant; and hPL continues to be produced. These significant modifications of the perfusion system have permitted the investigators to increase the duration of perfusion to 48 h while preserving normal metabolic fu nction of ultrastructurally intact tissue as demonstrated by ultra str uctural observations. This perfusion model device provides biohazard p recautions and may be applied to other studies of placental physiology . (C) 1996 W. B. Saunders Company Ltd