Porphyrin-laser photodynamic induction of focal brain necrosis
- VA Medical Center, Salt Lake City, UT (USA)
A noninvasive photodynamic method has been developed to produce focal brain necrosis using porphyrin activated in vivo with laser light. After peripheral injection of the photosensitive porphyrin derivative, Photofrin I, mice were irradiated on the posterior lateral aspect of the head through the intact depilated scalp with 632 nm argon-dye laser light. Animals were studied at one, two and seven days after irradiation. Blood-brain barrier damage was detected by the intravenous injection of Evans blue, horseradish peroxidase and heterologous immunoglobulins. At one and two days after irradiation, the lesions were characterized by extravasation of immunoglobulin and Evans blue, and by edema, ischemia and infiltration by monocytes. On the seventh day after irradiation, the lesion was smaller than it had been two days after irradiation, and had reactive changes at its edges and coagulative necrosis at its center. Extravasation of Evans blue and immunoglobulin was markedly reduced by the seventh day after irradiation, but uptake of horseradish peroxidase by macrophages located at the periphery of the lesion was evident.
- OSTI ID:
- 5403832
- Journal Information:
- Journal of Neuropathology and Experimental Neurology; (USA), Journal Name: Journal of Neuropathology and Experimental Neurology; (USA) Vol. 48:5; ISSN 0022-3069; ISSN JNENA
- Country of Publication:
- United States
- Language:
- English
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL EFFECTS
BODY
BRAIN
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM
ELECTROMAGNETIC RADIATION
ENZYMES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
LASER RADIATION
LASERS
MAMMALS
MICE
NECROSIS
NERVOUS SYSTEM
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OXIDOREDUCTASES
PATHOLOGICAL CHANGES
PEROXIDASES
PORPHYRINS
RADIATIONS
RODENTS
VERTEBRATES