Pre-clinical study of low power laser phototherapy (LPT) in the prevention and rehabilitation of chemo-induced mucosites in hamsters

• Grant number: 09/10254-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2009
• End date: October 31, 2010
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Marcia Martins Marques
• Grantee: Talita Christine Camilo Lopez
• Host Institution: Faculdade de Odontologia (FO). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The oral mucosite is a common complication in the treatment of the cancer. The development of effective interventions for its prevention and treatment is seen as high priority for supportive care cancer patients. The phototherapy with low intensity laser (LPT) due to its antiinflammatory effect could be of im portance for these patients. The objective of the present study is to investigate the effect of the LPT for prevention and treatment of oral mucosite induced by 5-FU in hamsters. Ninety-six hamsters will be randomly assigned in 4 groups: Control (with no treatment), Preventive (LPT from D-5 to D+5); Therapeutic (LPT from D+5 to D+15) and Conjugated (Preventive + Therapeutic - LPT from D-5 to D+15). All the animals will receive intraperitoneal injection of 5-FU in days 0 and 2. At days 3 and 4 the right jugal mucosa of all animals will be scratched. The irradiation parameters will be the following: laser of GaAlAs (red visible-660 nm), beam area of 0,042cm2, power of 40 mW, fluency of 10 J/cm2, in 6 points, applied in contact mode, 6 seconds/point. The irradiations will be carried once a day, in number dependent of the experimental group. Clinical photographs of the mucosae of all the animals will be taken daily. In days 0, 5, 10 and 15 six animals of each group will be sacrificed, weighed and the jugal mucosa will be removed for histopathologic analysis. The clinical photographs and the corresponding histological sections will be classified using a blind examination (e.g. the examiner will not know the groups of the material analyzed) in scores from zero to 3, according to Lima et al., 2005. These analyses will be carried out at 2 distinct moments with 1 week-interval to test the intra examiner reproducibility. After the confirmation of this reproducibility using the Kappa analysis, the clinical and histological scores observed during the experimental time will be used for the construction of contingency tables with the application of the qui-square test or Fisher test in order to verify possible associations between them the scores and the days of observation for the four groups. The normality of the weight data will be analyzed for determine the type of analysis of the variance to be done considering the main effects of groups and days. For the multiple comparisons, the tests of Tukey or Dunn will be used. In all the tests the level of significance of 5% or the corresponding p-value will be adopted. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CAMILO LOPEZ, TALITA CHRISTINE; MARTINS, MANOELA DOMINGUES; SANTOS PAVESI, VANESSA CHRISTINA; FERREIRA, LEILA SOARES; BUSSADORI, SANDRA KALIL; MOREIRA, MARIA STELLA; MARQUES, MARCIA MARTINS. Effect of laser phototherapy in the prevention and treatment of chemo-induced mucositis in hamsters. BRAZILIAN ORAL RESEARCH, v. 27, n. 4, p. 7-pg., 2013-07-01. (09/10254-4)

TALITA CHRISTINE CAMILO LOPEZ; MANOELA DOMINGUES MARTINS; VANESSA CHRISTINA SANTOS PAVESI; LEILA SOARES FERREIRA; SANDRA KALIL BUSSADORI; MARIA STELLA MOREIRA; MARCIA MARTINS MARQUES. Effect of laser phototherapy in the prevention and treatment of chemo-induced mucositis in hamsters. Brazilian Oral Research, v. 27, n. 4, p. 342-348, 2013-06-11. (09/10254-4)