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Biomedical subjects

R L Magin

Publications and source records attributed to R L Magin.

74 records · Page 5Linked to original sources
PubMedDate not supplied

Distribution of adriamycin in mice under conditions of local hyperthermia which improve systemic drug therapy.

Local tumor hyperthermia (LTH) (43 degrees C for 60 minutes) enhanced the effectiveness of Adriamycin (ADR) (10 mg/kg iv) administered systemically against the 16C mouse mammary adenocarcinoma. LTH was produced by the local application of 2450 MHz microwaves to sc implanted tumors. During LTH the intratumor temperature uniformity was +/- 0.5 degrees C and the rectal temperatures were 36 degrees C--38 degrees C. The simultaneous application of LTH and ADR resulted in tumor growth delays which were greater than those expected from the addition of individual treatments. Enhanced effectiveness of these treatments did not occur if the two treatments were separated by 4 hours. Cures were observed only in the treatment groups that received drug and heat simultaneously. Measurements of the tissue distribution of ADR and its metabolites using 14C-ADR indicated that the uptake of radioactivity in the heated tumors was not increased by LTH. A greater percentage of the radioactivity in heated tumors was recovered as ADR metabolites and correspondingly less radioactivity was recovered as unchanged ADR.

Adenocarcinoma↗
PubMedDate not supplied

Measurement of sodium fluorescein wash-in time constants in subjects with peripheral vascular disease.

The authors developed a noninvasive two-channel dynamic dermofluorometer that can quantitatively follow the rapid skin wash-in kinetics of a fluorescent dye to provide an assessment of local skin perfusion. The dermofluorometer was tested in normal subjects and diabetic patients with and without peripheral vascular disease. After an intravenous injection of 1-2 mL of a 10% solution of sodium fluorescein (1.1-2.8 mg/kg), the fluorescent signal was monitored from two sites on the skin surfaces of the forearm and foot. A 3.2-mm-diameter glass fiberoptic bundle was used both to transmit the excitation light (489 nm) and to receive the fluorescent emission (517 nm). Dermofluorometer readings were recorded approximately every second for 10-15 minutes following the injection. The time course of the fluorescein signal intensity was fit to a single exponential curve characterized by a wash-in time constant. There was no significant difference in arm wash-in time constants. Foot wash-in time constants were increased in diabetic patients who had past histories of foot ulcers relative to diabetic patients without a history of foot ulcers (3.2 vs 1.6 min., p < 0.05). Foot wash-in time constants were decreased in diabetic patients who had active infected foot ulcers. This study demonstrates the ability of the dynamic dermofluorometer to measure wash-in constants that reflect the local skin perfusion in less than 15 minutes after a low intravenous dose of sodium fluorescein.

Fiber Optic Technology↗