Photodynamic Antitumor and Antimicrobial Activities of Free-Base Tetra(4-methylthiolphenyl)chlorin and Its Tin(IV) Complex.

Meso-tetra(4-methylthiolphenyl)chlorin (3) and its Sn(IV) complex (3-Sn) have been synthesized and characterized. The heavy atom effects of the Sn(IV) ion and sulfur atoms result in relatively high singlet oxygen quantum yield values of 0.40 and 0.48. The photodynamic activities against MCF-7 breast cancer cells were determined through irradiation with a Thorlabs 660 nm LED for 30 min (280 mW.cm-2 ). IC50 values of 7.8 and 3.9 µM were obtained, respectively. 3-Sn was found to have significant photodynamic antimicrobial activity against both gram-(+) S. aureus and gram-(-) E. coli bacteria upon irradiation with a Thorlabs 660 nm LED for 75 min.

Validity of covering-up sun-protection habits: Association of observations and self-report.

BACKGROUND: Few studies have reported the accuracy of measures used to assess sun-protection practices. Valid measures are critical to the internal validity and use of skin cancer control research. OBJECTIVES: We sought to validate self-reported covering-up practices of pool-goers. METHODS: A total of 162 lifeguards and 201 parent/child pairs from 16 pools in 4 metropolitan regions in the United States completed a survey and a 4-day sun-habits diary. Observations of sun-protective behaviors were conducted on two occasions. RESULTS: Agreement between observations and diaries ranged from slight to substantial, with most values in the fair to moderate range. Highest agreement was observed for parent hat use (kappa = 0.58-0.70). There was no systematic pattern of over- or under-reporting among the 3 study groups. LIMITATIONS: Potential reactivity and a relatively affluent sample are limitations. CONCLUSION: There was little over-reporting and no systematic bias, which increases confidence in reliance on verbal reports of these behaviors in surveys and intervention research.