Cytotoxicity of spermine oxidation products to multidrug resistant melanoma M14 ADR2 cells: Sensitization by the MDL 72527 lysosomotropic compound

It has been confirmed that multidrug resistant (MDR) human melanoma cells are more sensitive than their wild-type counterparts to H(2)O(2) and aldehydes, the products of bovine serum amine oxidase (BSAO)-catalyzed oxidation of spermine. The metabolites formed by BSAO and spermine are more toxic than exogenous H(2)O(2) and acrolein, even thou-h their concentration is lower during the initial phase of incubation due to their more gradual release than the exogenous products. Both wild-type and MDR cells, after pre-treatment with MDL 72527, an inactivator of polyamine oxidase and a lysosomotropic compound, show to be sensitized to subsequent exposure to BSAO/spermine. Evidence of ultrastructural aberrations and acridine orange release from lysosomes is presented in this work that is in favor of the permeabilization of the lysosomal membrane as the major cause of sensitization by MDL 72527. Owing to its lysosomotropic effect, pre-treatment with MDL 72527 amplifies the ability of the metabolites formed from spermine by oxidative deamination to induce cell death. Since it is conceivable that combined treatment with a lysosomotropic compound and BSAO/spermine would be effective against tumor cells, it is of interest to search for such novel compounds, which might be promising for application in a therapeutic setting

Validity and reliability of a photoelectric cells system for the evaluation of change of direction and lateral jumping abilities in collegiate basketball athletes

The validity and reliability of the Optojump system were investigated for jumping height and flight time in vertical jump tests. Conversely, the purpose of the present study was to investigate the validity and reliability of the Optojump system for measuring contact time and lateral displacement in change of direction and lateral jump tests. Thirty basketball collegiate athletes were tested on two 10 m sprints with a 60° (COD60) or 180° (COD180) change of direction, lateral controlled (CLRJ) and maximal (MLRJ) rebound jump, and lateral countermovement (LCMJ) and squat (LSJ) jump with the concomitant use of two force plates and the Optojump system for the measurement of contact time in COD60, COD180, CLRJ, MLRJ, and lateral jumping distance in all the lateral jump tests. Almost perfect coefficients (r ≥ 0.95) emerged for contact time in COD60, COD180, CLRJ, MLRJ, although a systematic bias was found for COD60 (-0.01 s). Good-to-excellent reliability was found for almost all the measurements of contact time and lateral jumping distance for change of direction and lateral jump tests. Therefore, the use of Optojump system for testing change of direction and lateral jumping abilities should be executed with caution, avoiding misinterpretation of data