AECIO MASSAYOSHI YAMADA JUNIOR

AECIO MASSAYOSHI YAMADA JUNIOR

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Photosensitization of Actinobacillus actinomycetemcomitans with malachite green and methylene blue: microbiological analysis
2006 - YAMADA JUNIOR, A.M.; PRATES, R.A.; HASHIMOTO, M.C.; SUZUKI, L.C.; CAI, S.; RIBEIRO, M.S.
Histological analysis in ligature induced periodontitis in rats following photodynamic therapy
2006 - YAMADA JUNIOR, A.M.; PRATES, R.A.; SUZUKI, L.C.; VILLA, N.; CAI, S.; RIBEIRO, M.S.
Bactericidal effect of malachite green and red laser on Antinobacillus actinomycetemcomitans
2007 - PRATES, RENATO A.; YAMADA JUNIOR, AECIO M.; SUZUKI, LUIS C.; HASHIMOTO, MARIA C.E.; CAI, SILVANA; SOARES, SHEILA G.; GOMES, LAERCIO; RIBEIRO, MARTHA S.
Comparative study between the effects of photodynamic therapy and conventional therapy on microbial reduction in ligature-induced peri-implantitis in dogs
2005 - HAYEK, R.R.A.; ARAUJO, N.S.; GIOSO, M.A.; FERREIRA, J.; BAPTISTA SOBRINHO, C.A.; YAMADA JUNIOR, A.M.; RIBEIRO, M.S.
The irradiation parameters investigation of photodynamic therapy on yeast cells
2008 - PRATES, RENATO A.; SILVA, ERIQUES G. da; YAMADA JUNIOR, AECIO M.; SUZUKI, LUIS C.; PAULA, CLAUDETE R.; RIBEIRO, MARTHA S.
It has been proposed that photodynamic therapy (PDT) can inactivate microbial cells. A range of photosensitizers and light sources were reported as well as different fluence parameters and dye concentrations. However, much more knowledge regarding to the role of fluences, irradiation time and irradiance are required for a better understanding of the photodynamic efficiency. The aims of this study were to investigate the role of light parameters on the photoinactivation of yeast cells, and compare cell survivors in different growing phases following PDT. To perform this study, a suspension (106cfu/mL) of Candida albicans ATCC-90028 was used in log and stationary-phase. Three irradiances 100mW/cm2, 200mW/cm2 and 300mW/cm2 were compared under 3min, 6min and 9min of irradiation, resulting in fluences of 18, 36, 54, 72,108 and 162J/cm2. The light source used was a laser emitting at 660nm with output power of 30, 60 and 90mW. As photosensitizer, 100μΜ methylene blue was used. PDT was efficient against yeast cells (6 log reduction) in log and stationary-phase. Neither photosensitizer nor light alone presented any reduction of cell viability. The increase of irradiance and time of irradiation showed a clearly improvement of cell photoinactivation. Interestingly, the same fluences in different irradiances presented dissimilar effects on cell viability. The irradiance and time of irradiation are important in PDT efficiency. Fluence per se is not the best parameter to compare photoinativation effects on yeast cells. The growing-phases presented the same susceptibility under C. albicans photoinactivation.
Photosensitization of Aggregatibacter actinomycetemcomitans with methylene blue: A microbiological and spectroscopic study
2008 - YAMADA JUNIOR, AECIO; PRATES, RENATO A.; CAI, SILVANA; RIBEIRO, MARTHA S.
The aim of this study was to determinate the efficiency of methylene blue (MB) to kill cultures of Aggregatibacter actinomycetemcomitans under red light and to investigate MB photobleaching by optical absorption spectroscopy. Bacteria were diluted in aqueous solution, putted in glass tubes and distributed in 5 groups: (L-MB-) control group; (L+MB-) laser alone by 5min; (L-MB+) MB alone through 5min; (3L+MB+) MB+laser 3min; (5L+MB+) MB+laser 5min. Laser parameters were P=30mW, λ=660nm, E=9J in 5min and E=5.4J in 3min. The samples were diluted and bacterial colonies were counted and converted into colony forming units (CFU). Absorption spectra of the MB-stained bacterial suspension and photosensitized bacterial suspension were obtained. Groups L-MB-, L+MB-, and L-MB+ did not show a decrease in CFU/mL. L+MB+ groups showed a significant decrease in CFU/mL but no statistically significant differences were observed between 3min and 5min. Spectroscopy showed that MB is photodegraded after irradiation and that dimer species are more notably consumed than monomeric species. These results suggest that MB is a suitable photosensitizer to reduce A. actinomycetemcomitans, and that 3min of irradiation are enough to produce a significant effect. Due to the spectral changes observed on MB solution after irradiation a type I mechanism may be involved.
Light parameters influence cell viability in antifungal photodynamic therapy in a fluence and rate fluence-dependent manner
2009 - PRATES, RENATO A.; SILVA, ERIQUES G. da; YAMADA JUNIOR, AECIO M.; SUZUKI, LUIS C.; PAULA, CLAUDETE R.; RIBEIRO, MARTHA S.
The aim of this study was to investigate the influence of light parameters on yeast cells. It has been proposed for many years that photodynamic therapy (PDT) can inactivate microbial cells. A number of photosensitizer and light sources were reported in different light parameters and in a range of dye concentrations. However, much more knowledge concerning the importance of fluence, fluence rate and exposure time are required for a better understanding of the photodynamic efficiency. Suspensions (106 CFU/mL) of Candida albicans, Candida krusei, and Cryptococcus neoformans var. grubii were used. Two fluence rates, 100 and 300 mW/cm2 were compared at 3, 6, and 9 min of irradiation, resulting fluences from 18 to 162 J/cm2. The light source was a laser emitting at λ = 660 nm with output power adjusted at 30 and 90 mW. As photosensitizer, one hundred-μM methylene blue was used. Temperature was monitored to verify possible heat effect and reactive oxygen species (ROS) formation was evaluated. The same fluence in different fluence rates showed dissimilar levels of inactivation on yeast cells as well as in ROS formation. In addition, the increase of the fluence rate showed an improvement on cell photoinactivation. PDT was efficient against yeast cells (6 log reduction), and no significant temperature increase was observed. Fluence per se should not be used as an isolate parameter to compare photoinactivation effects on yeast cells. The higher fluence rate was more effective than the lower one. Furthermore, an adequate duration of light exposure cannot be discarded.
Histomorphometric and microbial assessment of photodynamic therapy as an adjuvant treatment for periodontilis: A short-term evaluation of inflammatory periodontal conditions and bacterial reduction in a rat model
2011 - PRATES, RENATO A.; YAMADA JUNIOR, AECIO M.; SUZUKI, LUIS C.; FRANÇA, CRISTIANE M.; CAI, SILVANA; MAYER, MARCIA P.A.; RIBEIRO, ADRIANA C.; RIBEIRO, MARTHA S.