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Purpose: Boron neutron capture therapy (BNCT) combines selective accumulation of 10B carriers in tumor tissue with subsequent neutron irradiation. BNCT has been proposed for the treatment of multiple, non-resectable, diffuse tumors in lung. The aim of the present study was to evaluate the therapeutic efficacy and toxicity of BNCT in an experimental model of lung metastases of colon carcinoma in BDIX rats and perform complementary survival studies. Materials and methods: We evaluated tumor control and toxicity in lung 2 weeks post-BNCT at 2 dose levels, including 5 experimental groups per dose level: T0 (euthanized pre-treatment), Boronophenylalanine-BNCT (BPA-BNCT), BPA + Sodium decahydrodecaborate-BNCT ((BPA + GB-10)-BNCT), Beam only (BO) and Sham (no treatment, same manipulation). Tumor response was assessed employing macroscopic and microscopic end-points. An additional experiment was performed to evaluate survival and oxygen saturation in blood. Results and conclusions: No dose-limiting signs of short/medium-term toxicity were observed in lung. All end-points revealed statistically significant BNCT-induced tumor control vs Sham at both dose levels. The survival experiment showed a statistically significant 45% increase in post-treatment survival time in the BNCT group (48 days) versus Sham (33 days). These data consistently revealed growth suppression of lung metastases by BNCT with no manifest lung toxicity. Boron Neutron Capture Therapy suppresses growth of experimental lung metastases No BNCT-induced short/medium-term toxicity in lung is associated with tumor control Boron Neutron Capture Therapy increased post-treatment survival time by 45% [ABSTRACT FROM AUTHOR] more...

Background. We previously demonstrated the therapeutic success of sequential boron neutron capture therapy (Seq-BNCT) in the hamster cheek pouch oral cancer model. It consists of BPA-BNCT followed by GB-10-BNCT 24 or 48 hours later. Additionally, we proved that tumor blood vessel normalization with thalidomide prior to BPA-BNCT improves tumor control. The aim of the present study was to evaluate the therapeutic efficacy and explore potential boron microdistribution changes in Seq-BNCT preceded by tumor blood vessel normalization. Material and Methods. Tumor bearing animals were treated with thalidomide for tumor blood vessel normalization, followed by Seq-BNCT (Th+ Seq-BNCT) or Seq-Beam Only (Th+ Seq-BO) in the window of normalization. Boron microdistribution was assessed by neutron autoradiography. Results. Th+ Seq-BNCT induced overall tumor response of 100%, with 87 (4)% complete tumor response. No cases of severe mucositis in dose-limiting precancerous tissue were observed. Differences in boron homogeneity between tumors pre-treated and not pre-treated with thalidomide were observed. Conclusion. Th+ Seq-BNCT achieved, for the first time, response in all treated tumors. Increased homogeneity in tumor boron microdistribution is associated to an improvement in tumor control. [ABSTRACT FROM AUTHOR] more...

Aim: To evaluate vascular morphology and density, angiogenic switch activation, vascular endothelial growth factor (VEGF) expression, and endothelial cell (EC) proliferation in the hamster cheek pouch (HCP) model of oral cancer., Materials and Methods: Immunohistochemical detection of factor VIII, 5'-Bromo-2'-Deoxyuridine (BrdU) and VEGF was performed in pre-malignant and tumoral tissues., Results: Activation of angiogenesis was detected adjacent to epithelial dysplasia. Vascularized area and perimeter (p<0.001) increased in dysplasias and tumors. Tumor blood vessels exhibited an enhanced vascular compression (p<0.001) and structural alterations. EC proliferation was similar in dysplasias and carcinomas. An increase in vascular density, EC proliferation and VEGF expression was found in potentially malignant tissues but not in carcinomas., Conclusion: The angiogenic switch occurs in the dysplastic stage preceding tumor development in the HCP model of oral cancer. In potentially malignant tissues, increased VEGF expression favors EC proliferation and an increase in vascular density. Conversely, in tumors, VEGF is no longer of pivotal importance., (Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.) more...

Background: Normalization of tumor blood vessels improves drug and oxygen delivery to cancer cells. The aim of this study was to develop a technique to normalize blood vessels in the hamster cheek pouch model of oral cancer., Materials and Methods: Tumor-bearing hamsters were treated with thalidomide and were compared with controls., Results: Twenty eight hours after treatment with thalidomide, the blood vessels of premalignant tissue observable in vivo became narrower and less tortuous than those of controls; Evans Blue Dye extravasation in tumor was significantly reduced (indicating a reduction in aberrant tumor vascular hyperpermeability that compromises blood flow), and tumor blood vessel morphology in histological sections, labeled for Factor VIII, revealed a significant reduction in compressive forces. These findings indicated blood vessel normalization with a window of 48 h., Conclusion: The technique developed herein has rendered the hamster oral cancer model amenable to research, with the potential benefit of vascular normalization in head and neck cancer therapy. more...

Most research conducted by the dental scientific community is presented at the Annual Meetings of the different Divisions and Sections of IADR. This research acquires real value when the results are published in peer-reviewed journals. A useful indicator of the publication efficiency of research work is the rate of publication (PR), i.e., the ratio between the quantity of presentations and subsequent publications in peer-reviewed journals. The aim of this study was to analyze the PR of the presentations at the Sections and Divisions of the Latin American Region of the International Association for Dental Research (IADR). We considered the presentations at the Annual Meetings of Argentina, Brazil, Chile and Peru held in 2002 and 2003 and their corresponding publications indexed in PubMed from 2002 to 2009. For Venezuela, we analyzed the meetings held in 2002 and 2005, because they did not hold consecutive annual meetings. Presentation periods were selected based on previous data that report an interval of up to five years between presentation and publication. The number of presentations and the PR are related to the number of years that Sections and Divisions have existed. In Brazil and Argentina, PR (expressed as 1 publication: x presentations) is 1:3. The amount of research in Brazil is almost 8 times higher than in Argentina. Newer Sections and Divisions have produced fewer presentations, and the PR is also lower. We hope that this type of analysis will encourage the promotion of dental research at the different institutions and in the different vacancy areas of research, and facilitate exchange among researchers in the Region, enabling greater use to be made of their scientific activities. more...