Publications by authors named "Patrícia Nascimento de Assis"

4 Publications

  • Page 1 of 1

Photodynamic Antimicrobial Chemotherapy (PACT) in osteomyelitis induced by Staphylococcus aureus: Microbiological and histological study.

J Photochem Photobiol B 2015 Aug 9;149:235-42. Epub 2015 Jun 9.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, Salvador, BA 40110-150, Brazil; National Institute of Optics and Photonics, University of São Paulo, Physics Institute of São Carlos, São Carlos, SP 13560-970, Brazil; Camilo Castelo Branco University, Núcleo do Parque Tecnológico de São José dos Campos, São José dos Campos, SP 12247-004, Brazil. Electronic address:

Osteomyelitis is an inflammation either of medullar spaces or of the surface of cortical bones, which represents a bacterial infection. Photodynamic Antimicrobial Chemotherapy (PACT) is a treatment based on a cytotoxic photochemical reaction that induces a series of metabolic reactions and culminates in bacterial suppression. Such effect led to the idea that it could be used as a treatment of osteomyelitis. Following approval by the Animal Experimentation Committee of the School of Dentistry of the Federal University of Bahia, the present randomized study used eighty Wistar rats with the aim to evaluate, by microbiological and histological analysis, the effects of Photodynamic Antimicrobial Chemotherapy - PACT on tibial surgical bone defects in rats infected by Staphylococcus aureus. The animals were divided in groups: Control (non-infected); Control Osteomyelitis Induction; Saline solution; Photosensitizer; Red Laser and PACT - on this group, a diode laser (40mW; λ660nm ∅=0.04cm(2), CW, 10J/cm(2)) was used in combination with 5μg/ml of toluidine blue as the photosensitizer. On the microbiological study, immediately after treatment, the PACT group presented a bacterial reduction of 97.4% (p<0.001). Thirty days after treatment, there was a bacterial reduction of more than 99.9% (p<0.001). In the histological study, it was observed that the PACT group demonstrated an intense presence of osteocytes and absence of bone sequestration and micro-abscesses. The PACT using toluidine blue was effective in reducing the number of S. aureus enabling a better quality bone repair.
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http://dx.doi.org/10.1016/j.jphotobiol.2015.06.005DOI Listing
August 2015

Souring control in fluid samples of oil industry using a multiple ligand simultaneous docking (MLSD) strategy.

J Biomol Struct Dyn 2015 22;33(6):1176-84. Epub 2014 Jul 22.

a Instituto de Física, Universidade Federal da Bahia , Rua Barão de Geremoabo s/n, Ondina, Salvador , BA , Brazil.

We have used docking techniques in order to propose potential inhibitors to the enzymes adenosine phosphosulfate reductase and adenosine triphosphate sulfurylase that are responsible, among other deleterious effects, for causing souring of oil and gas reservoirs. Three candidates selected through molecular docking revealed new and improved polar and hydrophobic interactions with the above-mentioned enzymes. Microbiological laboratory assays performed subsequently corroborated the results of computer modelling that the three compounds can efficiently control the biogenic sulfide production.
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http://dx.doi.org/10.1080/07391102.2014.937461DOI Listing
December 2015

Novel potential inhibitors for adenylylsulfate reductase to control souring of water in oil industries.

J Biomol Struct Dyn 2014 13;32(11):1780-92. Epub 2013 Sep 13.

a Instituto de Física, Universidade Federal da Bahia , Rua Barão de Geremoabo s/n - Ondina, Salvador , BA , 40.300-000 , Brasil .

The biogenic production of hydrogen sulfide gas by sulfate-reducing bacteria (SRB) causes serious economic problems for natural gas and oil industry. One of the key enzymes important in this biologic process is adenosine phosphosulfate reductase (APSr). Using virtual screening technique we have discovered 15 compounds that are novel potential APSr inhibitors. Three of them have been selected for molecular docking and microbiological studies which have shown good inhibition of SRB in the produced water from the oil industry.
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http://dx.doi.org/10.1080/07391102.2013.834850DOI Listing
May 2015

A new preclinical approach for treating chronic osteomyelitis induced by Staphylococcus aureus: in vitro and in vivo study on photodynamic antimicrobial therapy (PAmT).

Lasers Med Sci 2014 Mar 25;29(2):789-95. Epub 2013 Aug 25.

Center of Biophotonics, School of Dentistry, Federal University of Bahia, 62 Araujo Pinho Ave, Canela, Salvador, Bahia, 40110-150, Brazil,

Osteomyelitis is an acute or chronic inflammation in the marrow spaces in the superficial or cortical bone, and can be associated with bacterial or fungal infections. Chronic osteomyelitis represents a major health problem due to its difficult treatment and increased morbidity. Photodynamic antimicrobial therapy (PAmT) is a treatment based on a cytotoxic photochemical reaction in which a bright light produced by a laser system and an active photosensitizer absorbed by cells leads to a process of activation that induces a series of metabolic reactions that culminates a bacterial killing. The aim of the present randomized study was to evaluate, by in vitro and in vivo microbiological analysis, the effects of PAmT on tibial surgical bone defects in rats infected by Staphylococcus aureus using bacterial counts carried out immediately and after 30 days after treatment as outcome measure. In the preliminary in vitro study, a diode laser (λ660 nm; 40 mW; ϕ = 0.4 cm(2); 5 or 10 J/cm(2)) and 5, 10, and 15 μg/mL toluidine blue were tested, and the best parameter was chosen for the in vivo study. The concentration of 5 μg/mL was selected to perform the decontamination of S. aureus-infected tibial bone defects in rats. The findings were subjected to statistical analysis. For all PAmTs groups, with the different concentrations, treatment showed significant reductions (p < 0.001) in the amount of bacteria. The in vivo study PAmT group presented a bacterial reduction of 97.4% (p < 0.001). The PAmT using toluidine blue was effective in reducing the number of S. aureus in both in vitro and in vivo studies.
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http://dx.doi.org/10.1007/s10103-013-1422-2DOI Listing
March 2014
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