Evidence for intracellular aggregation of hypericin and the impact on its photocytotoxicity in PAM 212 murine keratinocytes.

We have assessed photoinduced toxicity of hypericin in PAM 212 murine keratinocytes and the relationship between concentration, incubation time and light fluence to evaluate the effect of intracellular aggregation at high concentrations. Confocal microscopy was used to establish the subcellular localization of hypericin at 5 and 50 microM and incubation times of 1 and 3 h. From fluorescence uptake time course studies, intracellular hypericin was demonstrated to exist predominantly in the monomeric form for up to 26 h incubation at 5 microM. However, there was a pronounced aggregation effect at 50 microM, with intracellular hypericin fluorescence levels initially showing an increase followed by a decrease with incubation time. This effect was subsequently shown to exert an effect on the phototoxicity of hypericin. On irradiation, the photocytotoxicity for 1 and 7 h incubation with 50 microM hypericin was comparable, whereas using 5 microM the photocytotoxicity showed good correlation with the intracellular fluorescence measurements at 1 and 7 h incubation.

Intraoperative care of the transplant patient.

Patients undergoing abdominal organ transplantation have extensive comorbidities that can affect many organ systems including the cardiovascular system. Intraoperative anesthesia care can be very challenging and requires thorough understanding of the disease specific physiology as well as knowledge of the comorbidities and the surgical procedure. There is no approach to intraoperative anesthesia care that will work equally well for every center but standardization of protocols for each transplant center will improve patient care and safety and ultimately contributes to superior outcomes. In this article we provide background and suggestions that will help with the development of standardized protocols for intraoperative management.