Biomimetic quantum dot-labeled B16F10 murine melanoma cells as a tool to monitor early steps of lung metastasis by in vivo imaging.

BACKGROUND: Numerous studies have proposed the use of fluorescent semiconductor nanoparticles or quantum dots (QDs) as novel tools to label cells and tumors. However, QD applications are limited by their toxicity in biological systems and little is known about whether QDs affect the capacity of cancer cells to metastasize. Previously, we described the "biomimetic" synthesis of CdTe-QDs (QDs-glutathione [GSH]) with increased biocompatibility and the potential utility in labeling cells. PURPOSE: In order to determine the feasibility of using QDs-GSH as a tool for tracking tumor cells during early metastasis, we characterized here for the first time, the in vitro and in vivo effects of the incorporation of green or red biomimetic QDs-GSH into B16F10 cells, a syngeneic mouse melanoma line for metastasis assays in C57BL/6 mice. METHODS: B16F10 cells were labeled with green or red biomimetic QDs-GSH in the presence or absence of n-acetylcysteine. Then, migration, invasion and proliferation of labeled B16F10 were evaluated in vitro. Finally, the B16F10 cells labeled with red QDs-GSH were used to monitor in vivo lung metastasis at early time points (5 minutes to 24 hours) or after 21 days in C57BL/6 mice. RESULTS: We developed a methodology that allows obtaining QDs-GSH-labeled B16F10 cells (nearly 100% viable labeled cells), which remained viable for at least 5 days and migrated similarly to control cells. However, proliferation, invasion, and the capacity to form metastatic nodules in the lungs were severely attenuated. Fluorescence imaging revealed that distribution/accumulation of QDs-GSH-labeled B16F10 cells could be tracked following injection into C57BL/6 mice (syngeneic preclinical metastasis model) and that these cells preferentially accumulated in the perialveolar area in lungs as early as 5 minutes post-injection. CONCLUSION: The methodology described here represents a useful alternative for monitoring initial events during tumor cell metastasis.

Gold nanoparticles as tracking devices to shed light on the role of caveolin-1 in early stages of melanoma metastasis.

AIM: To track early events during lung metastasis, we labeled cells expressing (B16F10CAV1) or lacking CAV1 (B16F10mock) with gold nanoparticles conjugated to the peptide TAT (AuNPs-PEG-TAT). METHODS: B16F10 expressing or lacking CAV1 were labeled with AuNPs-PEG-TAT. The physicochemical properties and cytotoxicity of these nanoparticles, as well as their effects on migration and invasiveness of B16F10 cells in vitro were evaluated. Ex vivo lung distribution of the labeled cells after tail vein injection into C57BL/6 mice was examined. RESULTS: AuNPs-PEG-TAT did not affect B16F10 viability, migration and invasiveness. The metastatic and tumorigenic capability of the labeled B16F10 was also not modified in comparison to unlabeled B16F10 cells. CAV1 expression favored the retention of B16F10 cells in the lungs of mice 2 h post injection, suggesting CAV1 promoted adherence to endothelial cells and transendothelial migration. CONCLUSIONS: We developed a protocol to label B16F10 cells with AuNPs-PEG-TAT that permits subsequent tracking of cells in mice. CAV1 overexpression was found to increase retention and transendothelial migration of B16F10 cells in the lung.

Peritaje Médico-Militar en Dermatología / Military medical inspection in dermatology

Se estudió el resultado del peritaje médico-militar, realizado por el Servicio de Dermatología del Hospital Militar Central "Dr. Carlos J. Finlay" durante 10 años, con el objetivo de conocer las enfermedades cutáneas que más frecuentemente causan bajas en las FAR. Se analizaron las siguientes variables: grado militar, porcentajes, aptitud FAR y calidad del proceso de selección para el ingreso. En los períodos estudiados (1985-1989 y 1990-1994) la dermatosis reaccional más frecuente fue la dermatitis de contacto por botas, que de un período a otro disminuyó de 33,7 por ciento a 13,9 por ciento. En las dermatosis cosmetológicas, las más frecuentes y con carácter creciente fueron la pseudofoliculitis de la barba (14,5 por ciento y 15,2 por ciento) y el acné polimorfo (16,5 por ciento y 17,7 por ciento). En las dermatosis infecciosas se observó en el segundo período una disminución significativa

Leishmaniasis cutánea en nicaragua: estudio comparativo de dos modalidades terapéuticas / Skin leishmaniasis in Nicaragua: a comparative study of two therapeutic approaches

Se realiza un estudio comparativo de la eficacia curativa en la leishmaniasis cutánea entre el metronidazol y el pentostan, antimonio pentavalente reconocido para esta dolencia, pero no exento de efectos secundarios. Se analiza la posible influencia del tiempo de evolución de las lesiones al inicio del tratamiento con ambas modalidades terapéuticas, así como la reducción del área media de las lesiones a los 30 días de comenzado el tratamiento. En esta revisión bibliográfica efectuada se pone de manifiesto el controvertido efecto terapéutico sobre esta enfermedad exótica