The effect of aminolaevulinic acid-induced, protoporphyrin IX-mediated photodynamic therapy on the cremaster muscle microcirculation in vivo.

The effect of photodynamic therapy on normal striated muscle was investigated using 30 adult male rats. Animals were divided into six groups. Three control groups received phosphate-buffered saline by gavage and violet light at 105, 178 and 300 mW cm-2 respectively. Three experimental groups received aminolaevulinic acid (ALA; 200 mg kg-1) and violet light at 105, 178 and 300 mW cm-2 respectively. After exposure of the cremaster muscle animals were allowed to equilibrate and vessel diameters and bloodflow assessed. Following photoactivation measurements were taken every 10 min over a 2 h period. Photoactivation of experimental groups at the two higher power densities resulted in an initial decrease in both arteriolar and venular diameters, and a concomitant decrease in blood flow. The magnitude of these changes and the degree of recovery by the end of the observation period was related to power density. No effects were observed in the control groups. These results suggest that microcirculatory damage may contribute to the mechanism of action of photodynamic therapy with ALA

Monitoring blood flow responses during topical ALA-PDT

Photodynamic therapy (PDT) using topical 5-aminolevulinic acid (ALA) is currently used as a clinical treatment for nonmelanoma skin cancers. In order to optimize PDT treatment, vascular disruption early in treatment must be identified and prevented. We present blood flow responses to topical ALA-PDT in a preclinical model and basal cell carcinoma patients assessed by diffuse correlation spectroscopy (DCS). Our results show that ALA-PDT induced early blood flow changes and these changes were irradiance dependent. It is clear that there exists considerable variation in the blood flow responses in patients from lesion to lesion. Monitoring blood flow parameter may be useful for assessing ALA-PDT response and planning

Progress report no. 5

Includes bibliographical referencesProgress report; June 30, 1974U.S. Atomic Energy Commission contract AT(11-1)225

Plasma Dynamics

Contains reports on six research projects.National Science Foundation (Grant ENG79-07047)U.S. Air Force - Office of Scientific Research (Grant AFOSR77-3143D)U.S. Air Force - Office of Scientific Research (Contract AFOSR82-0063)U.S. Department of Energy (Contract DE-ACO2-78-ET-51013)U.S. Department of Energy (Contract DE-AC02-78ET-53073.A002

Description and validation of a modular training system for laparoscopic nephrectomy

Background and Purpose: Laparoscopic nephrectomy (LN) has largely replaced open nephrectomy. The aim of this study was to describe a validated modular system for training urologists in LN in the context of the shorter training times available in the current era. Methods: After attendance at dry and wet laboratory courses, three mentees (trainee, new consultant, and an experienced open surgeon) were mentored through a five-module LN training system in our center followed by the mentee's own hospital. A minimum of 25 independent procedures were then performed by mentees in their own hospital. Results: There were 17 to 32 mentored cases needed to become competent in LN, followed by up to 5 observed cases in the mentee's own center. Subsequently, data from the first 105 cases (80 LN and 25 laparoscopic nephroureterectomies [LNU]) performed by the three surgeons after the end of their training without observation by their mentor were retrospectively collected and analyzed. There were three conversions (2.9%). For LN and LNU, respectively: median operative time was 140 minutes (65-390 min) and 180 minutes (90-300 min); median estimated blood loss was 30 mL (0-2000 mL) and 50 mL (0-2000 mL); median postoperative stay was 4 days (2-45 days) and 6 days (3-27 days). Four (3.8%) patients needed a postoperative transfusion. There was no 30-day mortality. Conclusion: Mentees matched the median British Association for Urological Surgeons (BAUS) registry operative time (LN, 120-180 min, LNU, 180-240 min) and had lower conversion rates (2.9% vs 6.4% for BAUS). Mentees matched median BAUS database reported blood loss (LN and LN