Radioactive treatment of a murine melanoma using a (32)P-patch.

OBJECTIVE: To evaluate the therapeutic effects of a (32)P-patch in the treatment of a murine melanoma. MATERIALS AND METHODS: Thirty male C57BL6 mice were divided into two groups: treated and control. Superficial tumors were induced in both groups by injecting B16F1 melanoma at about 10 cells/mouse subcutaneously. Tumors developed 10-15 days after transplantation and the (32)P-patch was applied on palpable tumors of the treated group. Tumor growth was followed up in both groups by measuring tumor size with a caliper. After the follow-up period, the animals were killed and tumor samples of the treated and control groups were collected for histological study by preparing paraffin sections stained with hematoxylin-eosin. RESULTS: The (32)P-patch showed the absence of radioactivity leakage in vitro and the homogeneous distribution of the radionuclide. The skin surface at the application site of the (32)P-patch appeared hairless, and erythema developed, but reversed to normal after a few days in the treated group. Control of tumor growth was achieved in the treated group compared with the control group, although complete remission did not occur. CONCLUSION: The (32)P-patch tested for the treatment of a murine melanoma model showed its efficacy, as tumor growth was retarded after application of the patch Nevertheless, adjustment of some therapeutic parameters and/or combining the patch with other treatment modalities may be necessary to achieve complete regression. The P-patch represents a powerful tool to individualize the treatment of melanoma.

Modificación de la biodistribución de los glóbulos rojos marcados con 99mtc en la anemia ferropénica / Alteration in the biodistribution of 99mTc-RBC in an animal model of ferropenic anemia

Objetivo: Evaluar la biodistribución de 99mTc-GR en un modelo animal de anemia ferropénica. Materiales y métodos: Se utilizaron ratas alimentadas con dietas con diferente contenido de Fe: grupo A (anemia severa, 6.5 ppm), grupo B (anemia moderada, 18 ppm) y grupo C (control, 100 ppm). Se realizó la marcación in vivo de los 99mTc-GR y se evaluó la EBM y su biodistribución a los 30 minutos y a las 24 horas en sangre, hígado, bazo, tracto gastrointestinal, riñones, corazón y pulmones. Los resultados se expresaron como concentración de actividad porcentual (CA por ciento). Resultados: En todos los grupos la EBM fue superior al 98 por ciento. Se observó un aumento de CA por ciento en bazo a las 24 horas en el grupo A, acompañado de una disminución de la CA por ciento del pool sanguíneo posiblemente por aumento del secuestro esplénico de los GR. En los tres grupos hubo un aumento de la CA por ciento en riñón a las 24 horas. Conclusión: La biodistribución de 99mTc-GR se ve modificada en la anemia ferropénica.

Aim: To evaluate the biodistribution of 99mTc-RBC in an animal model of ferropenic anemia. Materials and methods: We used rats which were fed with different iron contents diets: group A (severeanemia, 6.5 ppm), group B (moderate anemia, 18 ppm) and group C (control, 100 ppm). We performed the in vivo labeling of RBC and evaluated the labeling efficiency and the biodistribution at 30 minutes and 24 hours in blood, liver, spleen, gastrointestinal tract, kidneys, heart and lungs. The results were expressed as activity concentration percentage (CA percent). Results: In all groups the labeling efficiency was higher than 98 percent. We observed an increase of CA percent in spleen at 24 hours in the group A, followed by a decrease of CA percent in blood. This could be a consequence of an increase of splenic uptake of RBC. An increase in CA percent in kidney was obtained at 24 hours for all the groups. Conclusion: An alteration in the RBC biodistribution is observed in an animal model of ferropenic anemia.