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da Silva RAA, Trinca RB, Vilela HS, Braga RR. Composite Containing Calcium Phosphate Particles Functionalized with 10-MDP. J Dent Res 2024; 103:427-433. [PMID: 38284313 DOI: 10.1177/00220345231225459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2024] Open
Abstract
The phosphate ester monomer 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) is capable of bonding to hydroxyapatite and, for this reason, is a key component of several self-etch adhesives. In this study, dicalcium phosphate dihydrate particles (DCPD; CaHPO4.2H2O) were functionalized with 10-MDP and used to formulate an experimental composite with 50 vol% inorganic content (3:1 DCPD:silanated barium glass ratio) dispersed in a BisGMA/TEGDMA matrix. The tested hypothesis was that DCPD functionalization would improve the composite's mechanical performance without compromising Ca2+ release. Composites containing nonfunctionalized DCPD or only reinforcing glass (in both cases, with or without 10-MDP mixed in the resin phase) were used as controls. Materials were tested for degree of conversion (DC; by Fourier transform infrared spectroscopy), water sorption (WS) and solubility (SL; according to ISO 4049), biaxial flexural strength (BFS)/modulus (FM) after 24 h and 5 mo in water, and 28-d Ca2+ release in water (by plasma-coupled optical emission spectroscopy). Data were analyzed using analysis of variance/Tukey test (alpha: 5%). DCPD functionalization did not interfere with DC. The composite containing functionalized DCPD showed significantly lower WS and SL in comparison with the material formulated with nonfunctionalized particles. The presence of 10-MDP (as a functionalizing agent or dispersed in the resin phase) reduced the composite's initial BFS and FM. After 5 mo in water, the composite with functionalized DCPD and both glass-only composites were able to maintain their mechanical properties at levels statistically similar to what was observed after 24 h. Ca2+ release was significantly reduced in both formulations containing 10-MDP. In conclusion, DCPD functionalization with 10-MDP increased the composite's resistance to hydrolytic degradation, improving its mechanical stability after prolonged water storage. However, the impaired water transit at the particle-matrix interface led to a reduction in Ca2+ release.
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Affiliation(s)
- R A A da Silva
- School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil
| | - R B Trinca
- School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil
| | - H S Vilela
- School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil
| | - R R Braga
- School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil
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Esteca MV, Divino IA, Vieira da Silva AL, Severino MB, Braga RR, Ropelle ER, Simabuco FM, Baptista IL. Parkin is a critical player in the effects of caffeine over mitochondrial quality control pathways during skeletal muscle regeneration in mice. Acta Physiol (Oxf) 2024; 240:e14111. [PMID: 38314948 DOI: 10.1111/apha.14111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 01/04/2024] [Accepted: 01/12/2024] [Indexed: 02/07/2024]
Abstract
AIM This study aimed to investigate the effects of caffeine on pathways associated with mitochondrial quality control and mitochondrial capacity during skeletal muscle regeneration, focusing on the role of Parkin, a key protein involved in mitophagy. METHODS We used in vitro C2C12 myoblast during differentiation with and without caffeine in the medium, and we evaluated several markers of mitochondrial quality control pathways and myotube growth. In vivo experiments, we used C57BL/6J (WT) and Parkintm 1Shn lineage (Parkin-/- ) mice and injured tibial anterior muscle. The mice regenerated TA muscle for 3, 10, and 21 days with or without caffeine ingestion. TA muscle was used to analyze the protein content of several markers of mitochondrial quality pathways, muscle satellite cell differentiation, and protein synthesis. Furthermore, it analyzed mtDNA, mitochondrial respiration, and myofiber growth. RESULTS C2C12 differentiation experiments showed that caffeine decreased Parkin content, potentially leading to increased DRP1 and PGC-1α content and altered mitochondrial population, thereby enhancing growth capacity. Using Parkin-/- mice, we found that caffeine intake during the regenerative process induces an increase in AMPKα phosphorylation and PGC-1α and TFAM content, changes that were partly Parkin-dependent. In addition, the absence of Parkin potentiates the ergogenic effect of caffeine by increasing mitochondrial capacity and myotube growth. Those effects are related to increased ATF4 content and activation of protein synthesis pathways, such as increased 4E-BP1 phosphorylation. CONCLUSION These findings demonstrate that caffeine ingestion changes mitochondrial quality control during skeletal muscle regeneration, and Parkin is a central player in those mechanisms.
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Affiliation(s)
- M V Esteca
- Laboratory of Cell and Tissue Biology, School of Applied Sciences, University of Campinas, Limeira, Brazil
| | - I A Divino
- Laboratory of Cell and Tissue Biology, School of Applied Sciences, University of Campinas, Limeira, Brazil
| | - A L Vieira da Silva
- Laboratory of Cell and Tissue Biology, School of Applied Sciences, University of Campinas, Limeira, Brazil
| | - M B Severino
- Laboratory of Cell and Tissue Biology, School of Applied Sciences, University of Campinas, Limeira, Brazil
- Multidisciplinarity Laboratory of Food and Health, School of Applied Sciences, University of Campinas, Limeira, Brazil
| | - R R Braga
- Laboratory of Molecular Biology of Exercise, School of Applied Sciences, University of Campinas, Limeira, Brazil
| | - E R Ropelle
- Laboratory of Molecular Biology of Exercise, School of Applied Sciences, University of Campinas, Limeira, Brazil
| | - F M Simabuco
- Multidisciplinarity Laboratory of Food and Health, School of Applied Sciences, University of Campinas, Limeira, Brazil
- Department of Biochemistry, Federal University of São Paulo, São Paulo, Brazil
| | - I L Baptista
- Laboratory of Cell and Tissue Biology, School of Applied Sciences, University of Campinas, Limeira, Brazil
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Damasceno de Lima R, Fudoli Lins Vieira R, Rosetto Muñoz V, Chaix A, Azevedo Macedo AP, Calheiros Antunes G, Felonato M, Rosseto Braga R, Castelo Branco Ramos Nakandakari S, Calais Gaspar R, Ramos da Silva AS, Esper Cintra D, Pereira de Moura L, Mekary RA, Rochete Ropelle E, Pauli JR. Time-restricted feeding combined with resistance exercise prevents obesity and improves lipid metabolism in the liver of mice fed a high-fat diet. Am J Physiol Endocrinol Metab 2023; 325:E513-E528. [PMID: 37755454 PMCID: PMC10864020 DOI: 10.1152/ajpendo.00129.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 09/13/2023] [Accepted: 09/13/2023] [Indexed: 09/28/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD), a condition characterized by the accumulation of fat in the liver, is estimated to be the most common liver disease worldwide. Obesity is a major risk factor and contributor, and, accordingly, weight loss can improve NAFLD. Previous studies in preclinical models of diet-induced obesity and fatty liver disease have shown the independent benefits of resistance exercise training (RT) and time-restricted feeding (TRF) in preventing weight gain and hepatic build-up of fat. Here, we tested the combined effect of TRF and RT on obesity and NAFLD in mice fed a high-fat diet. Our results showed that both TRF-8-h food access in the active phase-and RT-consisting of three weekly sessions of ladder climbing-attenuated body weight gain, improved glycemic homeostasis, and decreased the accumulation of lipids in the liver. TRF combined with RT improved the respiratory exchange rate, energy expenditure, and mitochondrial respiration in the liver. Furthermore, gene expression analysis in the liver revealed lower mRNA expression of lipogenesis and inflammation genes along with increased mRNA of fatty acid oxidation genes in the TRF + RT group. Importantly, combined TRF + RT was shown to be more efficient in preventing obesity and metabolic disorders. In conclusion, TRF and RT exert complementary actions compared with isolated interventions, with significant effects on metabolic disorders and NAFLD in mice.NEW & NOTEWORTHY Whether time-restricted feeding (TRF) combined with resistance exercise training (RT) may be more efficient compared with these interventions alone is still unclear. We show that when combined with RT, TRF provided additional benefits, being more effective in increasing energy expenditure, preventing weight gain, and regulating glycemic homeostasis than each intervention alone. Thus, our results demonstrate that TRF and RT have complementary actions on some synergistic pathways that prevented obesity and hepatic liver accumulation.
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Affiliation(s)
- Robson Damasceno de Lima
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, Brazil
| | - Renan Fudoli Lins Vieira
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, Brazil
| | - Vitor Rosetto Muñoz
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, Brazil
| | - Amandine Chaix
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, United States
| | - Ana Paula Azevedo Macedo
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, Brazil
| | - Gabriel Calheiros Antunes
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, Brazil
| | - Maíra Felonato
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, Brazil
| | - Renata Rosseto Braga
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, Brazil
| | | | - Rafael Calais Gaspar
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, Brazil
| | - Adelino Sanchez Ramos da Silva
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, and Postgraduate Program in Physical Education and Sport, School of Physical Education and Sport of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Dennys Esper Cintra
- Laboratory of Nutritional Genomics (LabGeN), University of Campinas (UNICAMP), Limeira, Brazil
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, Brazil
| | - Leandro Pereira de Moura
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, Brazil
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, Brazil
| | - Rania A Mekary
- Massachusetts College of Pharmacy and Health Sciences (MCPHS) University, Boston, Massachusetts, United States
- Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Eduardo Rochete Ropelle
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, Brazil
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, Brazil
| | - José Rodrigo Pauli
- Laboratory of Molecular Biology of Exercise (LaBMEx), University of Campinas (UNICAMP), Limeira, Brazil
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center (OCRC), University of Campinas, Campinas, Brazil
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Muñoz VR, Botezelli JD, Gaspar RC, da Rocha AL, Vieira RFL, Crisol BM, Braga RR, Severino MB, Nakandakari SCBR, Antunes GC, Brunetto SQ, Ramos CD, Velloso LA, Simabuco FM, de Moura LP, da Silva ASR, Ropelle ER, Cintra DE, Pauli JR. Effects of short-term endurance and strength exercise in the molecular regulation of skeletal muscle in hyperinsulinemic and hyperglycemic Slc2a4 +/- mice. Cell Mol Life Sci 2023; 80:122. [PMID: 37052684 DOI: 10.1007/s00018-023-04771-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 03/08/2023] [Accepted: 03/28/2023] [Indexed: 04/14/2023]
Abstract
OBJECTIVE Intriguingly, hyperinsulinemia, and hyperglycemia can predispose insulin resistance, obesity, and type 2 diabetes, leading to metabolic disturbances. Conversely, physical exercise stimulates skeletal muscle glucose uptake, improving whole-body glucose homeostasis. Therefore, we investigated the impact of short-term physical activity in a mouse model (Slc2a4+/-) that spontaneously develops hyperinsulinemia and hyperglycemia even when fed on a chow diet. METHODS Slc2a4+/- mice were used, that performed 5 days of endurance or strength exercise training. Further analysis included physiological tests (GTT and ITT), skeletal muscle glucose uptake, skeletal muscle RNA-sequencing, mitochondrial function, and experiments with C2C12 cell line. RESULTS When Slc2a4+/- mice were submitted to the endurance or strength training protocol, improvements were observed in the skeletal muscle glucose uptake and glucose metabolism, associated with broad transcriptomic modulation, that was, in part, related to mitochondrial adaptations. The endurance training, but not the strength protocol, was effective in improving skeletal muscle mitochondrial activity and unfolded protein response markers (UPRmt). Moreover, experiments with C2C12 cells indicated that insulin or glucose levels could contribute to these mitochondrial adaptations in skeletal muscle. CONCLUSIONS Both short-term exercise protocols were efficient in whole-body glucose homeostasis and insulin resistance. While endurance exercise plays an important role in transcriptome and mitochondrial activity, strength exercise mostly affects post-translational mechanisms and protein synthesis in skeletal muscle. Thus, the performance of both types of physical exercise proved to be a very effective way to mitigate the impacts of hyperglycemia and hyperinsulinemia in the Slc2a4+/- mouse model.
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Affiliation(s)
- Vitor Rosetto Muñoz
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.
| | - José Diego Botezelli
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Rafael Calais Gaspar
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Alisson L da Rocha
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Renan Fudoli Lins Vieira
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Barbara Moreira Crisol
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Renata Rosseto Braga
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Matheus Brandemarte Severino
- Multidisciplinary Laboratory of Food and Health (LabMAS), School of Applied Sciences (FCA), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | | | - Gabriel Calheiros Antunes
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Sérgio Q Brunetto
- Biomedical Engineering Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Celso D Ramos
- Biomedical Engineering Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Department of Radiology, University of Campinas, Campinas, São Paulo, 13084-970, Brazil
| | - Lício Augusto Velloso
- OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Laboratory of Cell Signaling, Department of Internal Medicine, University of Campinas, Campinas, São Paulo, 13084-970, Brazil
| | - Fernando Moreira Simabuco
- Multidisciplinary Laboratory of Food and Health (LabMAS), School of Applied Sciences (FCA), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Leandro Pereira de Moura
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
- OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Adelino Sanchez Ramos da Silva
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão, Preto Medical School, University of São Paulo (USP), School of Physical Education and Sport of Ribeirão Preto , Ribeirão Preto, São Paulo, Brazil
| | - Eduardo Rochete Ropelle
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
- OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- National Institute of Science and Technology of Obesity and Diabetes, University of Campinas (UNICAMP), Campinas , São Paulo, Brazil
| | - Dennys Esper Cintra
- Laboratory of Nutritional Genomics, University of Campinas (UNICAMP), Limeira,, São Paulo, Brazil
- OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - José Rodrigo Pauli
- Laboratory of Molecular Biology of Exercise, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil.
- OCRC - Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
- National Institute of Science and Technology of Obesity and Diabetes, University of Campinas (UNICAMP), Campinas , São Paulo, Brazil.
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Katashima CK, de Oliveira Micheletti T, Braga RR, Gaspar RS, Goeminne LJE, Moura-Assis A, Crisol BM, Brícola RS, Silva VRR, de Oliveira Ramos C, da Rocha AL, Tavares MR, Simabuco FM, Matheus VA, Buscaratti L, Marques-Souza H, Pazos P, Gonzalez-Touceda D, Tovar S, del Carmen García M, Neto JCR, Curi R, Hirabara SM, Brum PC, Prada PO, de Moura LP, Pauli JR, da Silva ASR, Cintra DE, Velloso LA, Ropelle ER. Evidence for a neuromuscular circuit involving hypothalamic interleukin-6 in the control of skeletal muscle metabolism. Sci Adv 2022; 8:eabm7355. [PMID: 35905178 PMCID: PMC9337767 DOI: 10.1126/sciadv.abm7355] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 06/15/2022] [Indexed: 05/31/2023]
Abstract
Hypothalamic interleukin-6 (IL6) exerts a broad metabolic control. Here, we demonstrated that IL6 activates the ERK1/2 pathway in the ventromedial hypothalamus (VMH), stimulating AMPK/ACC signaling and fatty acid oxidation in mouse skeletal muscle. Bioinformatics analysis revealed that the hypothalamic IL6/ERK1/2 axis is closely associated with fatty acid oxidation- and mitochondrial-related genes in the skeletal muscle of isogenic BXD mouse strains and humans. We showed that the hypothalamic IL6/ERK1/2 pathway requires the α2-adrenergic pathway to modify fatty acid skeletal muscle metabolism. To address the physiological relevance of these findings, we demonstrated that this neuromuscular circuit is required to underpin AMPK/ACC signaling activation and fatty acid oxidation after exercise. Last, the selective down-regulation of IL6 receptor in VMH abolished the effects of exercise to sustain AMPK and ACC phosphorylation and fatty acid oxidation in the muscle after exercise. Together, these data demonstrated that the IL6/ERK axis in VMH controls fatty acid metabolism in the skeletal muscle.
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Affiliation(s)
- Carlos Kiyoshi Katashima
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeria, São Paulo 13484-350, Brazil
| | - Thayana de Oliveira Micheletti
- Faculty of Medical Sciences, Department of Internal Medicine, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Renata Rosseto Braga
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeria, São Paulo 13484-350, Brazil
| | - Rodrigo Stellzer Gaspar
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeria, São Paulo 13484-350, Brazil
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Ludger J. E. Goeminne
- Laboratory of Integrative Systems Physiology, Interfaculty Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Alexandre Moura-Assis
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Barbara Moreira Crisol
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeria, São Paulo 13484-350, Brazil
| | - Rafael S. Brícola
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeria, São Paulo 13484-350, Brazil
| | - Vagner Ramon R. Silva
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeria, São Paulo 13484-350, Brazil
| | - Camila de Oliveira Ramos
- Laboratory of Nutritional Genomic, School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo 13484-350, Brazil
| | - Alisson L. da Rocha
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Pretol, São Paulo, Brazil
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Mariana Rosolen Tavares
- Multidisciplinary Laboratory of Food and Health (LabMAS), School of Applied Sciences (FCA), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Fernando Moreira Simabuco
- Multidisciplinary Laboratory of Food and Health (LabMAS), School of Applied Sciences (FCA), University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Valquiria Aparecida Matheus
- Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Lucas Buscaratti
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Henrique Marques-Souza
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Patricia Pazos
- Department of Physiology, Research Center of Molecular Medicine and Chronic Diseases (CIMUS) and CIBER Fisiopatología Obesidad y Nutrición (CB 06/03), Instituto de Salud Carlos III (ISCIII, Ministerio de Economía y Competitividad (MINECO), University of Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - David Gonzalez-Touceda
- Department of Physiology, Research Center of Molecular Medicine and Chronic Diseases (CIMUS) and CIBER Fisiopatología Obesidad y Nutrición (CB 06/03), Instituto de Salud Carlos III (ISCIII, Ministerio de Economía y Competitividad (MINECO), University of Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Sulay Tovar
- Department of Physiology, Research Center of Molecular Medicine and Chronic Diseases (CIMUS) and CIBER Fisiopatología Obesidad y Nutrición (CB 06/03), Instituto de Salud Carlos III (ISCIII, Ministerio de Economía y Competitividad (MINECO), University of Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - María del Carmen García
- Department of Physiology, Research Center of Molecular Medicine and Chronic Diseases (CIMUS) and CIBER Fisiopatología Obesidad y Nutrición (CB 06/03), Instituto de Salud Carlos III (ISCIII, Ministerio de Economía y Competitividad (MINECO), University of Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Jose Cesar Rosa Neto
- Immunometabolism Research Group, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-900, Brazil
| | - Rui Curi
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-900, Brazil
- Institute of Physical Activity Sciences and Sports, Cruzeiro do Sul University, São Paulo 01506-000, Brazil
| | - Sandro Massao Hirabara
- Institute of Physical Activity Sciences and Sports, Cruzeiro do Sul University, São Paulo 01506-000, Brazil
| | - Patrícia Chakur Brum
- School of Physical Education and Sport, University of São Paulo (USP), São Paulo 05508-030, Brazil
| | - Patrícia Oliveira Prada
- Faculty of Medical Sciences, Department of Internal Medicine, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Leandro P. de Moura
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeria, São Paulo 13484-350, Brazil
- CEPECE—Center of Research in Sport Sciences, School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo 13484-350, Brazil
| | - José Rodrigo Pauli
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeria, São Paulo 13484-350, Brazil
- CEPECE—Center of Research in Sport Sciences, School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo 13484-350, Brazil
| | - Adelino S. R. da Silva
- Postgraduate Program in Rehabilitation and Functional Performance, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Pretol, São Paulo, Brazil
- School of Physical Education and Sport of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Dennys Esper Cintra
- Laboratory of Nutritional Genomic, School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo 13484-350, Brazil
| | - Licio A. Velloso
- Faculty of Medical Sciences, Department of Internal Medicine, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
| | - Eduardo Rochete Ropelle
- Laboratory of Molecular Biology of Exercise (LaBMEx), School of Applied Sciences, University of Campinas (UNICAMP), Limeria, São Paulo 13484-350, Brazil
- Faculty of Medical Sciences, Department of Internal Medicine, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, University of Campinas (UNICAMP), Limeira, São Paulo, Brazil
- CEPECE—Center of Research in Sport Sciences, School of Applied Sciences, University of Campinas (UNICAMP), Limeira, São Paulo 13484-350, Brazil
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Nakano EL, de Souza A, Boaro L, Catalani LH, Braga RR, Gonçalves F. Polymerization Stress and Gap Formation of Self-adhesive, Bulk-fill and Flowable Composite Resins. Oper Dent 2020; 45:E308-E316. [PMID: 32516396 DOI: 10.2341/19-166-l] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/10/2020] [Indexed: 11/23/2022]
Abstract
CLINICAL RELEVANCE Bulk-fill materials show a similar or better performance than control flowable materials regarding interfacial integrity. However, some self-adhesive composites need improvements to achieve competitive performance. SUMMARY Objective: This laboratory study compared the polymerization stress and gap formation of self-adhesive, bulk-fill and control flowable composites. The degree of conversion (DC) and post-gel shrinkage were also assessed.Methods: Two self-adhesive (Vertise Flow and Fusio Liquid Dentin), two bulk-fill (Tetric N-Flow Bulk-Fill and Filtek Bulk-Fill Flowable Restorative), and two control flowable (Z350 XT Flowable Restorative and Tetric N-Flow) composites were evaluated. Polymerization stress (PS) was determined in a universal testing machine (n=5). Gap formation was evaluated by scanning electron microscopy in class I restorations (n=6). DC was measured by Fourier transform infrared spectroscopy (n=3). Post-gel volumetric shrinkage (VS) was measured using the strain gauge method (n=5). Data were submitted to one-way analysis of variance or a Kruskal-Wallis test (α=0.05).Results: Vertise Flow and Fusio Liquid Dentin presented the highest interfacial gap (27%±5% and 21%±6%, respectively), which was associated with their highest PS (4.1±0.8 MPa and 3.5±0.6 MPa, respectively) and DC (63%±2% and 60%±2%, respectively) in spite of the lowest VS (1.0%±0.2% and 1.0%±0.3%, respectively). Tetric N-Flow Bulk-Fill and Filtek Bulk-Fill Flowable Restorative presented similar PS (2.9± 0.3 MPa and 2.4±0.2 MPa, respectively) to both control materials. However, the Tetric N-Flow Bulk-Fill showed the lowest gap (7%±2%) and the highest DC (64.3%±0.4%), and the Filtek Bulk-fill presented a marginal gap (17.8%±3.4%) and a DC (54.5%±2.7%) similar to the control materials. The VS values of both bulk-fill materials were similar to those of Tetric N-Flow and lower than that of Z350 XT Flowable Restorative.Conclusions: Bulk-fill composites showed either similar or significantly lower interfacial gaps and PS than the control flowable composites. The self-adhesive composites showed a significantly higher gap percentage and PS than the control and bulk-fill materials.
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Viana Í, Alania Y, Feitosa S, Borges AB, Braga RR, Scaramucci T. Bioactive Materials Subjected to Erosion/Abrasion and Their Influence on Dental Tissues. Oper Dent 2020; 45:E114-E123. [PMID: 32053454 DOI: 10.2341/19-102-l] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE The objective of this study was to evaluate the effect of erosion or erosion-abrasion on bioactive materials and adjacent enamel/dentin areas. METHODS AND MATERIALS Enamel and dentin blocks (4×4×2 mm) were embedded side by side in acrylic resin, and a standardized cavity (1.2×4×1.5 mm) was prepared between them. Preparations were restored with the following materials: composite resin (Filtek Z350, control); experimental composite containing di-calcium phosphate dihydrate particles (DCPD); Giomer (Beautifil II), high viscosity glass ionomer cement (GIC, Fuji IX); and a resin-modified GIC (Fuji II LC). The specimens were submitted to two cycling models (n=10): erosion or erosion-abrasion. The challenges consisted of five-minute immersion in 0.3% citric acid solution, followed by 60-minute exposure to artificial saliva. Toothbrushing was carried out twice daily, 30 minutes after the first and last exposures to acid. Dental and material surface loss (SL, in μm) were determined by optical profilometry. Data were analyzed with Kruskal-Wallis and Dunn tests (α=0.05). RESULTS Under erosion, for enamel, only the GIC groups presented lower SL values than Z350 (p<0.001 for Fuji IX and p=0.018 for Fuji II LC). For dentin, none of the materials showed significantly lower SL values than Z350 (p>0.05). For material, the GICs had significantly higher SL values than those of Z350 (p<0.001 for Fuji IX and p=0.002 for Fuji II LC). Under erosion-abrasion, the enamel SL value was significantly lower around Fuji II LC compared with the other materials (p<0.05). No significant differences were observed among groups for dentin SL (p=0.063). The GICs and Giomer showed higher SL values than Z350 (p<0.001 for the GICs and p=0.041 for Giomer). CONCLUSION Both GIC-based materials were susceptible to erosive wear; however, they promoted the lowest erosive loss of adjacent enamel. Against erosion-abrasion, only Fuji II LC was able to reduce enamel loss. For dentin, none of the materials exhibited a significant protective effect.
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Shimokawa C, Turbino ML, Giannini M, Braga RR, Price RB. Effect of Curing Light and Exposure Time on the Polymerization of Bulk-Fill Resin-Based Composites in Molar Teeth. Oper Dent 2020; 45:E141-E155. [PMID: 32053458 DOI: 10.2341/19-126-l] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES This study examined the influence of different light-curing units (LCUs) and exposure times on the microhardness across bulk-fill resin-based composite (RBC) restorations in a molar tooth. METHODS AND MATERIALS Tip diameter, radiant power, radiant exitance, emission spectra, and light beam profile were measured on two single-emission-peak LCUs (Celalux 3 and DeepCure-S) and two multiple-peak LCUs (Bluephase 20i and Valo Grand). A mold was made using a human molar that had a 12-mm mesial-distal length, a 2.5-mm deep occlusal box, and two 4.5-mm deep proximal boxes. Two bulk-fill RBCs (Filtek Bulk Fill Posterior and Tetric EvoCeram Bulk Fill) were photoactivated for 10 seconds and for 20 seconds, with the light guide positioned at the center of the occlusal surface. Microhardness was then measured across the transverse surface of the restorations. The light that reached the bottom of the proximal boxes was examined. Data were statistically analyzed with the Student t-test, two-way analysis of variance, and the Tukey post hoc test (α=0.05). RESULTS The four LCUs were different regarding all the tested characteristics. Even when using LCUs with wide tips and a homogeneous beam profile, there were significant differences in the microhardness results obtained at the central and proximal regions of the RBCs (p<0.05). LCUs with wider tips used for 20 seconds produced higher microhardness values (p<0.05). The multiple-peak LCUs produced greater hardness values in Tetric EvoCeram Bulk Fill than did the single-emission-peak LCUs (Celalux 3 and DeepCure-S). Results for the light measured at the bottom of proximal boxes showed that little light reached these regions when the light tip was positioned at the center of restorations. CONCLUSIONS Curing lights with wide tips, homogeneous light beam profiles, and longer exposure times are preferred when light-curing large MOD restorations. Light curing from more than one position may be required for adequate photopolymerization.
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Pinto MFC, Alania Y, Natale LC, Magalhães AC, Braga RR. Effect of Bioactive Composites on Microhardness of Enamel Exposed to Carious Challenge. Eur J Prosthodont Restor Dent 2018; 26:122-128. [PMID: 30063306 DOI: 10.1922/ejprd_01781pinto07] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study verified if experimental composites containing calcium phosphate nanoparticles exert a protective effect against enamel demineralization. Three experimental resin-based composites containing 60 vol% of fillers were manipulated. Filler phase was constituted by silanized barium glass and 0%, 10% or 20% (by volume) of dicalcium phosphate dihydrate (DPCD) nanoparticles functionalized with the monomer triethylene glycol dimethacrylate (TEGDMA). Cavities (10 x 2 x 2 mm) were prepared in bovine enamel and restored using one of the experimental materials (n=10). Specimens were exposed to pH cycling (demineralizing solution: pH 5.0/4h, remineralizing solution: pH 7.0/20h, 14 days). Enamel Knoop microhardness (100g/10s) was measured on the surface (SH) and after transversal sectioning up to 90 μm depth (cross-sectional microhardness, CSH). Microhardness values and the percent of microhardness loss were analyzed ANOVA/Tukey test and Student's paired t-test (alpha: 5%). The materials did not differ in respect to SH. Enamel adjacent to DCPD-containing composite restorations showed smaller reductions in CSH (-1.2% to -3.5%) than the enamel from control group (-12.5%), while CSH of enamel restored with resin-modified glass ionomer was similar to the other groups (-4.5%). DCPD-containing composites reduced enamel demineralization in comparison to a conventional composite.
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Affiliation(s)
- M F C Pinto
- School of Dentistry, University of São Paulo
| | - Y Alania
- School of Dentistry, University of São Paulo
| | - L C Natale
- School of Dentistry, University of São Paulo
| | | | - R R Braga
- School of Dentistry, University of São Paulo
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Boaro LCC, Gonçalves F, Campos LMP, Rodrigues Júnior EC, Costa FV, Marques PA, Francci CE, Braga RR. Estudo Comparativo de Compósitos Bulk-Fill: Grau de Conversão, Contração Pós-Gel e Citotoxicidade. J Health Scie 2018. [DOI: 10.17921/2447-8938.2017v19n5p23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
O objetivo do presente estudo foi avaliar o grau de conversão, contração volumétrica pós-gel e citotoxicidade de seis compósitos comerciais “bulk-fill” de consistência regular e fluida. Foram testados seis compósitos do tipo bulk-fill, e dois compósitos restauradores convencionais, foram testados como controles. O grau de conversão foi determinado por espectroscopia FTIR, determinou-se a contração volumétrica pós-gel utilizando o método de strain-gage e a avaliação da citotoxicidade em fibroblastos humanos foi determinada indiretamente por ensaio de MTT. Os dados foram submetidos ao teste ANOVA / Tukey unidirecional. Todos os materiais, incluindo bulk-fill e convencionais, foram classificados como não tóxicos, com viabilidade celular superior a 70%. Os compósitos bulk-fill apresentaram contração volumétrica semelhante ou inferior (1,4 a 0,4%) em comparação com os compósitos convencionais (1,7- 2,1%). No entanto, apenas três dos compósitos bulk-fill foram capazes de manter uma conversão homogénea ao longo da profundidade de 4 mm. Sendo assim, o clínico deve prestar especial atenção na seleção de um material que realmente atinja o desempenho proposto de um material bulk-filll.Palavras-chave: Compósitos. Contração.
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Bornatowski H, Braga RR, Abilhoa V, Corrêa MFM. Feeding ecology and trophic comparisons of six shark species in a coastal ecosystem off southern Brazil. J Fish Biol 2014; 85:246-263. [PMID: 24919949 DOI: 10.1111/jfb.12417] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 03/28/2014] [Indexed: 06/03/2023]
Abstract
The diets of six shark species, Sphyrna lewini, Sphyrna zygaena, Carcharhinus obscurus, Carcharhinus limbatus, Rhizoprionodon lalandii and Galeocerdo cuvier, were investigated in a subtropical coastal ecosystem of southern Brazil. Stomach content data were obtained to assess foraging niche segregation and ontogenetic shifts in the diets of these sharks. Five of the shark species off the Paraná coast were ichthyophagous, with the exception of S. zygaena, which was teutophagous. With the exception of G. cuvier, which had a generalist diet, the other five species displayed specialization in their feeding. Ontogenetic shifts were observed in C. obscurus and S. lewini with large individuals consuming elasmobranchs. Owing to the diet overlap between C. obscurus and S. lewini, C. obscurus and C. limbatus and R. lalandii and C. limbatus, future studies on the spatial and temporal distributions of these species are needed to understand the extent of competitive interactions.
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Affiliation(s)
- H Bornatowski
- Universidade Federal do Paraná, Caixa Postal 19020, CEP 81531-980 Curitiba, PR, Brazil; GPIc - Grupo de Pesquisas em Ictiofauna, Museu de História Natural Capão da Imbuia, Rua Prof. Benedito Conceição, 407, 82810-080, Curitiba, PR, Brazil
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Natale LC, Rodrigues MC, Xavier TA, Simões A, de Souza DN, Braga RR. Ion release and mechanical properties of calcium silicate and calcium hydroxide materials used for pulp capping. Int Endod J 2014; 48:89-94. [PMID: 24646329 DOI: 10.1111/iej.12281] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 03/13/2014] [Indexed: 11/28/2022]
Abstract
AIM To compare the ion release and mechanical properties of a calcium hydroxide (Dycal) and two calcium silicate (MTA Angelus and Biodentine) cements. METHODOLOGY Calcium and hydroxyl ion release in water from 24-h set cements were calculated from titration with HCl (n = 3). Calcium release after 7, 14, 21 and 28 days at pH 5.5 and 7.0 was measured using ICP-OES (n = 6). Flexural strength (FS) and modulus (E) were tested after 48-h storage, and compressive strength (CS) was tested after 48 h and 7 days (n = 10). Ion release and mechanical data were subjected to anova/Tukey and Kruskal-Wallis/Mann-Whitney tests, respectively (α = 0.05). RESULTS Titration curves revealed that Dycal released significantly fewer ions in solution than calcium silicates (P < 0.001). Calcium release remained constant at pH 7.0, whilst at pH 5.5, it dropped significantly by 24% after 21 days (P < 0.05). At pH 5.5, MTA Angelus released significantly more calcium than Dycal (P < 0.01), whilst Biodentine had superior ion release than Dycal at pH 7.0 (P < 0.01). Biodentine had superior flexural strength, flexural modulus and compressive strength than the other cements, whilst MTA Angelus had higher modulus than Dycal (P < 0.001). CONCLUSIONS Immediate calcium and hydroxyl ion release in solution was significantly lower for Dycal. In general, all materials released constant calcium levels over 28 days, but release from Dycal was significantly lower than Biodentine and MTA Angelus depending on pH conditions. Biodentine had substantially higher strength and modulus than MTA Angelus and Dycal, both of which demonstrated low stress-bearing capabilities.
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Affiliation(s)
- L C Natale
- Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo, Brazil
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Giannini M, Di Francescantonio M, Pacheco RR, Boaro LCC, Braga RR. Characterization of Water Sorption, Solubility, and Roughness of Silorane- and Methacrylate-based Composite Resins. Oper Dent 2014; 39:264-72. [DOI: 10.2341/12-526-l] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Objective
The objective of this study was to evaluate the surface roughness (SR), water sorption (WS), and solubility (SO) of four composite resins after finishing/polishing and after one year of water storage.
Materials and Methods
Two low-shrinkage composites (Filtek Silorane [3M ESPE] and Aelite LS [Bisco Inc]) and two composites of conventional formulations (Heliomolar and Tetric N-Ceram [Ivoclar Vivadent]) were tested. Their respective finishing and polishing systems (Sof-Lex Discs, 3M ESPE; Finishing Discs Kit, Bisco Inc; and Astropol F, P, HP, Ivoclar Vivadent) were used according to the manufacturers' instructions. Ten disc-shaped specimens of each composite resin were made for each evaluation. Polished surfaces were analyzed using a profilometer after 24 hours and one year. For the WS and SO, the discs were stored in desiccators until constant mass was achieved. Specimens were then stored in water for seven days or one year, at which time the mass of each specimen was measured. The specimens were dried again and dried specimen mass determined. The WS and SO were calculated from these measurements. Data were analyzed by two-way analysis of variance and Tukey post hoc test (α=0.05).
Results
Filtek Silorane showed the lowest SR, WS, and SO means. Water storage for one year increased the WS means for all composite resins tested.
Conclusions
The silorane-based composite resin results were better than those obtained for methacrylate-based resins. One-year water storage did not change the SR and SO properties in any of the composite resins.
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Affiliation(s)
- M Giannini
- Marcelo Giannini, DDS, MS, PhD, associate professor, Piracicaba Dental School, University of Campinas, Department of Restorative Dentistry, Piracicaba, SP, Brazil
| | - M Di Francescantonio
- Marina Di Francescantonio, DDS, MS, PhD student, Piracicaba Dental School, State University of Campinas, Department of Restorative Dentistry, Piracicaba, SP, Brazil
| | - RR Pacheco
- Rafael Rocha Pacheco, DDS, MS student, Piracicaba Dental School, State University of Campinas, Department of Dental Materials, Piracicaba, SP, Brazil
| | - LC Cidreira Boaro
- Letícia Cristina Cidreira Boaro, DDS, MS, PhD, School of Dentistry, Universidade de Santo Amaro, Department of Dentistry, São Paulo, SP, Brazil
| | - RR Braga
- Roberto R Braga, DDS, MD, PhD, University of São Paulo, Department of Dental Materials, São Paulo, SP, Brazil
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Abstract
The long-term effectiveness of chlorhexidine as a matrix metalloproteinase (MMP) inhibitor may be compromised when water is incompletely removed during dentin bonding. This study challenged this anti-bond degradation strategy by testing the null hypothesis that wet-bonding with water or ethanol has no effect on the effectiveness of chlorhexidine in preventing hybrid layer degradation over an 18-month period. Acid-etched dentin was bonded under pulpal pressure simulation with Scotchbond MP and Single Bond 2, with water wet-bonding or with a hydrophobic adhesive with ethanol wet-bonding, with or without pre-treatment with chlorhexidine diacetate (CHD). Resin-dentin beams were prepared for bond strength and TEM evaluation after 24 hrs and after aging in artificial saliva for 9 and 18 mos. Bonds made to ethanol-saturated dentin did not change over time with preservation of hybrid layer integrity. Bonds made to CHD pre-treated acid-etched dentin with commercial adhesives with water wet-bonding were preserved after 9 mos but not after 18 mos, with severe hybrid layer degradation. The results led to rejection of the null hypothesis and highlight the concept of biomimetic water replacement from the collagen intrafibrillar compartments as the ultimate goal in extending the longevity of resin-dentin bonds.
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Affiliation(s)
- F T Sadek
- Department of Dental Materials, School of Dentistry, University of São Paulo, SP, Brazil
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Abstract
Polymerization stress development results from the complex interplay of volumetric shrinkage, reaction kinetics, and viscoelastic properties. The objective of this study was to examine the relationships among volumetric shrinkage, degree of conversion, rate of polymerization (RP(max)), and stress development for 2 model bis-GMA-based composites. Three irradiances were used--220, 400, or 600 mW/cm(2)--with exposure times adjusted to deliver the same radiant energy. Volumetric shrinkage was determined with a mercury dilatometer, degree of conversion and RP(max) by differential scanning calorimetry (DSC), and polymerization stress with a low-compliance device (Sakaguchi et al., 2004b). Results indicated that polymerization reaction rate and shrinkage were not correlated. Irradiance was directly related to polymerization reaction rate and to stress development. The group with the highest stress/degree of conversion exhibited the lowest RP(max), so it can be assumed, within the limitations of this study, that the conversion was most closely related to stress development.
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Affiliation(s)
- C S Pfeifer
- Department of Biomaterials and Oral Biochemistry, School of Dentistry, University of São Paulo, Av. Prof. Lineu Prestes, 2227 São Paulo, SP, Brazil.
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Abstract
The influence of composite organic content on polymerization stress development remains unclear. It was hypothesized that stress was directly related to differences in degree of conversion, volumetric shrinkage, elastic modulus, and maximum rate of polymerization encountered in composites containing different BisGMA (bisphenylglycidyl dimethacrylate) concentrations and TEGDMA (triethylene glycol dimethacrylate) and/or BisEMA (ethoxylated bisphenol-A dimethacrylate) as co-monomers. Stress was determined in a tensilometer. Volumetric shrinkage was measured with a mercury dilatometer. Elastic modulus was obtained by flexural test. We used fragments of flexural specimens to determine degree of conversion by FT-Raman spectroscopy. Reaction rate was determined by differential scanning calorimetry. Composites with lower BisGMA content and those containing TEGDMA showed higher stress, conversion, shrinkage, and elastic modulus. Polymerization rate did not vary significantly, except for the lower value of the 66% TEGDMA composite. We used linear regressions to evaluate the association between polymerization stress and conversion (R(2)=0.905), shrinkage (R(2)=0.825), and modulus (R(2)=0.623).
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Affiliation(s)
- F Gonçalves
- Dept. of Biomaterials and Oral Biochemistry, University of São Paulo, Av. Prof. Lineu Prestes, 2227, 05508-000 São Paulo, SP, Brazil
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Gonçalves F, Calheiros FC, Witzel MF, Kawano Y, Braga RR. Effect of photoactivation protocol and radiant exposure on monomer conversion and flexural strength of a resin composite after water and ethanol storage. J Biomed Mater Res B Appl Biomater 2007; 82:89-92. [PMID: 17078082 DOI: 10.1002/jbm.b.30708] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The use of soft-start photoactivation to reduce shrinkage stress has become widespread in restorative dentistry. However, an increased susceptibility to ethanol degradation of polymers formed by pulse-delay photoactivation was reported. It was hypothesized that reductions in flexural strength after ethanol storage were related not only to low curing rates, but also to the radiant exposure employed. A commercial composite was subjected to different curing protocols (continuous at high irradiance, continuous at low irradiance, and pulse-delay) and radiant exposures (6, 12, and 24 J/cm2). After 48 h, differences in degree of conversion were minimal and no differences in strength were detected among specimens stored in water. Ethanol storage caused significant strength reductions in pulse-delay and low irradiance specimens that received 6 J/cm2. The results suggest that when low irradiances or pulse-delay methods are used, a relatively high radiant exposure is necessary to originate a polymer network structure similar to that obtained by continuous high irradiance photoactivation.
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Affiliation(s)
- F Gonçalves
- Department of Dental Materials, University of São Paulo, School of Dentistry, Av. Prof. Lineu Prestes, 2227, São Paulo, 05508-900, Brazil
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Camurça-Vasconcelos ALF, Bevilaqua CML, Morais SM, Maciel MV, Costa CTC, Macedo ITF, Oliveira LMB, Braga RR, Silva RA, Vieira LS. Anthelmintic activity of Croton zehntneri and Lippia sidoides essential oils. Vet Parasitol 2007; 148:288-94. [PMID: 17629623 DOI: 10.1016/j.vetpar.2007.06.012] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 05/10/2007] [Accepted: 06/12/2007] [Indexed: 11/17/2022]
Abstract
Because of the development of anthelmintic resistant populations, the search for new drugs is essential to maintain the productivity of small ruminants. The aim of this study was to evaluate the anthelmintic activity of Croton zehntneri and Lippia sidoides essential oils and their major constituents, anethole and thymol. The effects of these oils and their constituents were determined by in vitro assays with the eggs and larvae of the sheep gastrointestinal nematode Haemonchus contortus. The two essential oils were evaluated on intestinal nematodes of mice at 800 mg kg(-1) dose. In the last experiment, the mice were treated with larger doses of L. sidoides, 1200 and 1600 mg kg(-1). The essential oils and their constituents prevented more than 98% of the H. contortus eggs from hatching at a concentration of 1.25 mg ml(-1) and inhibited more than 90% of H. contortus larval development at a concentration of 10 mg ml(-1). At a concentration of 800 mg kg(-1), the two essential oils were 46.3% and 11.64% effective against Syphacia obvelata and Aspiculuris tetraptera. At 1200 and 1600 mg kg(-1), L. sidoides essential oil's efficacy on the mouse worm burden was 57.6% and 68.9%, respectively. The fact that L. sidoides essential oil was almost 70% effective against mouse intestinal nematodes indicates it should be evaluated against gastrointestinal nematodes of sheep and goats.
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Abstract
Polymerization contraction stress of dental composites is often associated with marginal and interfacial failures of bonded restorations. The magnitude of stress depends on composite composition (filler content and matrix composition) and its ability to flow before gelation, which is related to the cavity configuration and curing characteristics of the composite. This article reviews variations among studies regarding contraction-stress-testing methods and contraction stress values of current composites, and discusses the validity of contraction stress studies in relation to results from microleakage tests. The effects of lower curing rates and alternative curing routines on contraction stress values are also discussed, as well as the use of low-elastic-modulus liners. Moreover, studies with experimental dimethacrylate-based composites and recent developments in low-shrinkage monomers are described.
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Affiliation(s)
- R R Braga
- University of São Paulo, School of Dentistry, Department of Dental Materials, São Paulo-SP 05508-900, Brazil.
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Romão W, Miranda WG, Cesar PF, Braga RR. Correlation between microleakage and cement thickness in three Class II inlay ceramic systems. Oper Dent 2004; 29:212-8. [PMID: 15088734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The objectives of this study include comparing the cement thickness and microleakage of Class II ceramic inlays built with three ceramic systems and verifying whether there was a correlation between those two variables. The ceramic systems used include: 1) Heat-pressed (IPS-Empress); 2) CAD-CAM (CEREC 2) and 3) Sintered (Colorlogic). Standardized MOD Class II inlay cavities with one proximal box extending below and the other extending above the cement-enamel junction (CEJ) were prepared in 30 extracted human molars and randomly assigned to three groups. The ceramic inlays were constructed according to manufacturer's instructions and cemented using a dual-cure resin cement (Variolink II). All teeth were mechanically cycled (100,000 cycles, 78N) and thermocycled (700 cycles, 5 degrees C-55 degrees C). After immersion in silver nitrate, the inlays were sectioned mesial-distally and evaluated with an optical microscope (40x). The cement thickness obtained by the Colorlogic system (enamel: 113 +/- 25 microm; dentin: 118 +/- 23 microm) was significantly higher than that obtained by CEREC (enamel: 78 +/- 14 microm; dentin: 87 +/- 13 microm) and Empress (enamel: 65 +/- 15 microm; dentin: 89 +/- 14 microm). Regarding dye penetration, there was no statistical difference among the three ceramic systems in enamel. At the dentin margins, the Colorlogic system resulted in a significantly higher penetration depth compared to CEREC and Empress, which had similar average values. No correlation was found between cement thickness and microleakage either in enamel or dentin for any of the ceramic systems.
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Affiliation(s)
- W Romão
- Department of Dental Materials, University of São Paulo, Brazil
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Ferracane JL, Ferracane LL, Braga RR. Effect of admixed high-density polyethylene (HDPE) spheres on contraction stress and properties of experimental composites. J Biomed Mater Res B Appl Biomater 2003; 66:318-23. [PMID: 12808590 DOI: 10.1002/jbm.b.10019] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Additives that provide stress relief may be incorporated into dental composites to reduce contraction stress (CS). This study attempted to test the hypothesis that conventional fillers could be replaced by high-density polyethylene (HDPE) spheres in hybrid and nanofill composites to reduce CS, but with minimal effect on mechanical properties. Nanofill and hybrid composites were made from a Bis-GMA/TEGDMA resin having either all silica nanofiller or 75 wt.% strontium glass + 5 wt.% silica and replacing some of the nanofiller or the glass with 0%, 5% (hybrid only), 10% or 20 wt.% HDPE. The surface of the HDPE was either left untreated or had a reactive gas surface treatment (RGST). Contraction stress (CS) was monitored for 10 min in a tensilometer (n = 5) after light curing for 60 s at 390 mW/cm(2). Other specimens (n = 5) were light cured 40 s from two sides in a light-curing unit and aged 1 d in water before testing fracture toughness (K(Ic)), flexure strength (FS), and modulus (E). Results were analyzed by ANOVA with Tukey's multiple comparison test at p < 0.05. There was no difference between composites with RGST and untreated HDPE except for FS-10% HDPE hybrid (RGST higher). An increased level of HDPE reduced contraction stress for both types of composites. Flexure strength, modulus (hybrid only), and fracture toughness were also reduced as the concentration of HDPE increased. SEM showed evidence for HDPE debonding and plastic deformation during fracture of the hybrid composites. In conclusion, the addition of HDPE spheres reduces contraction stress in composites, either through stress relief or a reduction in elastic modulus.
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Affiliation(s)
- J L Ferracane
- Department of Biomaterials and Biomechanics, Oregon Health & Science University, School of Dentistry, 611 SW Campus Drive, Portland, Oregon 97239, USA.
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Braga RR, Lainson R, Ishikawa EAY, Shaw JJ. Leishmania (Viannia) utingensis n. sp., a parasite from the sandfly Lutzomyia (Viannamyia) tuberculata in Amazonian Brazil. Parasite 2003; 10:111-8. [PMID: 12847917 DOI: 10.1051/parasite/2003102111] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A leishmanial parasite isolated in 1977 from a specimen of the sandfly Lutzomyia tuberculata from Pará State, Amazonian Brazil, has been characterized following its comparison with other species of Leishmania from the same region, using isoenzyme profiles, monoclonal antibodies and characterization of the miniexon gene repeat, using the polymerase chain reaction technique (PCR). It is described here under the name of Leishmania (Viannia) utingensis n. sp.
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Affiliation(s)
- R R Braga
- Departamento de Parasitologia, Instituto Evandro Chagas, Av. Almirante Barroso 492, 66090-000 Belém, Pará, Brazil
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Abstract
Dual-cured cements have been studied in terms of the hardness or degree of conversion achieved with different curing modes. However, little emphasis is given to the influence of the curing method on other mechanical properties. This study investigated the flexural strength, flexural modulus and hardness of four proprietary resin cements. Materials tested were: Enforce and Variolink II (light-, self- and dual-cured), RelyX ARC (self- and dual-cured) and C & B (self-cured). Specimens were fractured using a three-point bending test. Pre-failure loads corresponding to specific displacements of the cross-head were used for flexural modulus calculation. Knoop hardness (KHN) was measured on fragments obtained after the flexural test. Tests were performed after 24 h storage at 37 degrees C. RelyX ARC dual-cured showed higher flexural strength than the other groups. RelyX ARC and Variolink II depended upon photo-activation to achieve higher hardness values. Enforce showed similar hardness for dual- and self-curing modes. No correlation was found between flexural strength and hardness, indicating that other factors besides the degree of cure (e.g. filler content and monomer type) affect the flexural strength of composites. No statistical difference was detected in the flexural modulus among the different groups.
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Affiliation(s)
- R R Braga
- Department of Dental Materials, School of Dentistry, University of São Paulo, São Paulo, Brazil
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Braga RR, Ferracane JL. Contraction stress related to degree of conversion and reaction kinetics. J Dent Res 2002; 81:114-8. [PMID: 11827255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Polymerization shrinkage of composites bonded to cavity preparations generates stress on the tooth/restoration interface. The purpose of this study was to verify the influence of degree of conversion and speed of polymerization reaction on contraction stress. We prepared experimental composites with different curing rates by varying the concentration of inhibitor (butylated hydroxytoluene). We verified the effect of degree of conversion by submitting one of the composites to different photo-activation times. Contraction stress was monitored for 10 minutes in a tensilometer. Fourier-transformed infrared spectrometry was used for assessment of the degree of conversion. Volumetric shrinkage was determined by means of a mercury dilatometer. Degree of conversion and volumetric shrinkage showed a non-linear relationship with energy density. Degree of conversion showed a pronounced influence on stress. Increased inhibitor concentration reduced curing rate and contraction stress in composites, without compromising the final degree of conversion.
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Affiliation(s)
- R R Braga
- Department of Dental Materials, University of São Paulo, School of Dentistry, São Paulo, Brazil.
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Cesar PF, Miranda WG, Braga RR. Influence of shade and storage time on the flexural strength, flexural modulus, and hardness of composites used for indirect restorations. J Prosthet Dent 2001; 86:289-96. [PMID: 11552166 DOI: 10.1067/mpr.2001.114513] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
STATEMENT OF PROBLEM Fracture resistance, elastic modulus, and hydrolytic degradation resistance are important properties of indirect composite restorations. Composite systems developed specifically for indirect application are said to have enhanced mechanical properties due to their elevated monomer conversion. PURPOSE This study evaluated the influence of shade and the effect of 30-day water storage on the flexural strength, flexural modulus, and hardness of 4 commercially available indirect composite systems and 1 composite used with the direct technique. MATERIAL AND METHODS A variety of commercially available indirect resin composites (Artglass, Belleglass, Sculpture, and Targis) and 1 directly placed composite (Z100, control) were used. Specimens made with either incisal or dentin shade (n = 10) were fractured with a 3-point bending test. Pre-failure loads corresponding to specific displacements of the crosshead were used for flexural modulus calculation. Knoop hardness was measured on fragments (n = 3) obtained after the flexural test. Tests were performed after 24 hours and after a 30-day water storage at 37 degrees C. Flexural strength data were analyzed with the Weibull distribution. Flexural modulus and Knoop hardness data were analyzed with 3-way ANOVA and Tukey's post-hoc test (alpha=0.05). RESULTS In general, the directly placed composite (Z100) demonstrated flexural strength similar to that of Artglass, Targis, and Sculpture. Belleglass presented the highest flexural strength (221.7 MPa for incisal shade after 24 hours storage; 95% confidence interval: 208.3-235.4). Z100 demonstrated the highest flexural modulus (range: 10.9 +/- 0.6 to 12.0 +/- 0.9 GPa) and Targis the lowest (range: 5.1 +/- 0.5 to 5.9 +/- 0.9 GPa). Sculpture was the only material that showed differences in flexural strength with respect to shade (incisal-24 hours: 149.8 MPa; incisal-30 days: 148.7 MPa; dentin-24 hours: 200.0 MPa; dentin-30 days: 177.9 MPa). The flexural modulus and hardness of the dentin shade of Sculpture were higher than those of the incisal shade after 30 days. Belleglass also showed a significant difference in flexural modulus (dentin-24 hours: 11.1 GPa; incisal-24 hours: 9.6 GPa). The effect of water storage was more evident on hardness since all composite systems softened after 30 days. Prolonged water storage decreased flexural strength only for Artglass-dentin and Z100, both incisal and dentin shades. Water aging did not affect the flexural modulus of any composite tested. CONCLUSION In general, indirect composites did not show enhanced mechanical properties compared to the directly placed composite. Property differences due to shade were more evident for Sculpture. Prolonged water storage had a deleterious effect on the hardness of all composites tested. However, water storage did not affect the flexural strength of most of the indirect composites or the flexural modulus of any composite tested.
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Affiliation(s)
- P F Cesar
- Department of Dental Materials, Faculty of Dentistry, University of São Paulo, São Paulo, Brazil.
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26
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Abstract
OBJECTIVES The behavior of dual-cure cements over time remains unclear. This study evaluated the extrusion shear strength of the bond between feldsphatic porcelain and bovine dentin at different time intervals, using three adhesive systems based on dual-cure cements and one based on a self-cure cement. METHODS The adhesive systems evaluated included: C&B/One-Step, Enforce/Prime&Bond NT Dual-Cure, RelyX ARC/Single Bond and Variolink II/Syntac SC. Discs of bovine root dentin, 2.5 mm thick, had the root canal prepared with a standardized taper. Porcelain truncated cones etched with 4% hydrofluoric acid and silanized were bonded into the perforations. The extrusion shear test was performed after 15 min, 4 h, 12 h, 24 h, and 7 days. Data were analyzed using the Weibull distribution. The failure mode was accessed by stereomicroscope and SEM. RESULTS Statistical differences were found between 15 min and 7 days for Variolink II/Syntac SC and RelyX ARC/Single Bond, and between 15 min and 24 h for Enforce/Prime&Bond NT Dual-Cure. For C&B/One-Step, difference was found between 15 min and 4 h. Between 24 h and 7 days, only the system RelyX ARC/Single Bond showed a significant increase in the characteristic strength. SEM analysis revealed that the failure involved the hybrid layer/dentin or the hybrid layer/adhesive interfaces, regardless of the time interval and adhesive system. SIGNIFICANCE High characteristic strengths were observed after 15 min when dual-cure cements were used. In general, the values found at 24 h or 7 days were higher than at 15 min. However, there was always a considerable probability of bonding failure at low stress levels for all the systems tested.
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Affiliation(s)
- R R Braga
- Department of Dental Materials, University of São Paulo, School of Dentistry, São Paulo, Brazil.
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Braga RR, Cesar PF, Gonzaga CC. Tensile bond strength of filled and unfilled adhesives to dentin. Am J Dent 2000; 13:73-6. [PMID: 11764830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
PURPOSE To determine the tensile bond strength of three filled and two unfilled adhesives applied to bovine dentin. MATERIALS AND METHODS Fragments of the labial dentin of bovine incisors were embedded in PVC cylinders with self-cure acrylic resin, and ground flat using 200 grit and 600 grit sandpaper. The following adhesive systems were tested (n=10): Prime & Bond NT, Prime & Bond NT dual cure, Prime & Bond 2.1, OptiBond Solo and Single Bond. A 3 mm-diameter bonding surface was delimited using a perforated adhesive tape. After etching with 37% phosphoric acid and adhesive application, a resin-based composite truncated cone (TPH, shade A3) was built. Tensile test was performed after 24 hrs storage in distilled water at 37 degrees C. Failure mode was accessed using a x10 magnification stereomicroscope. RESULTS Weibull statistical analysis revealed significant differences in the characteristic strength between Single Bond and Prime & Bond NT dual cure, and between Single Bond and Prime & Bond 2.1. The Weibull parameter (m) was statistically similar among the five groups. Single Bond and Prime & Bond NT showed areas of dentin cohesive failure in most of the specimens. For OptiBond Solo, Prime & Bond NT dual cure and Prime & Bond 2.1 failure was predominantly adhesive.
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Affiliation(s)
- R R Braga
- Department of Dental Materials, University of São Paulo, SP, Brazil.
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28
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Abstract
STATEMENT OF PROBLEM One of the most critical steps of the porcelain restoration technique is cementation. Mechanical stress before the resin cement reaches a certain degree of polymerization can displace or even fracture the restoration. Dual-cure materials are intended to be more effective at early stages of polymerization because they contain both photoinitiator and components for chemically activated reaction. PURPOSE This study evaluated the early shear strength of bonding between porcelain and dentin, using dual-cure cements. MATERIAL AND METHODS Sixty nonrestored human molars and premolars were randomly divided in 12 groups. The dual-cure cements tested were Porcelite and Dual. A chemically activated cement was also tested (C&B luting composite). Ceramic pieces, 3 mm high, were etched with hydrofluoric acid, silane-coated, and then bonded to flat dentin surfaces with each of the cements, associated with Optibond adhesive system. Photoactivation was made by using a light unit with 450 mW/cm2. The specimens were stored in water at 37 degrees C. Testing times were 10, 30, 90 minutes, and 7 days (referred to as maximum strength). RESULTS Both Porcelite and Dual dual-cure cements show statistically similar shear strength for the same time interval. The chemically activated material showed statistically lower values when compared with both dual-cure cements, regardless of the time interval. Results at 7 days were much higher than those obtained at 90 minutes for the 3 cements tested. CONCLUSIONS Both dual-cure cements tested presented similar results. The bond strength of dual-cure cements to dentin was higher at all time intervals than that obtained for chemically activated material. The high values for the coefficient of variation confirmed the technique-sensitive nature of the porcelain/dentin bonding procedure. Although dual-cure cements reach higher bonding strength values faster than the chemically activated material, it is not recommended to stress the bonding until 90 minutes after cementation, because the strength at that time is much lower than the maximum.
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Affiliation(s)
- R R Braga
- University of São Paulo, Faculty of Dentistry, São Paulo, Brazil
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29
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Abstract
OBJECTIVES The aim of this study was to determine bond strength between dentin and three adhesive systems, by means of microtensile, shear and tensile tests. METHODS Extracted human molars were embedded in acrylic resin and had the dentin exposed on three of their smooth surfaces. On each surface a specimen was prepared to be submitted to either micro-tensile, shear or tensile bond strength testing. For shear and tensile tests, after adhesive application, a cone 3 mm high and diameter of 3 mm in the small surface was built with composite resin. The shear test was performed with a chisel. Tensile testing was made by pulling the resin cone via a metallic clamp. For micro-tensile testing, composite approximately 5 mm high was placed over the entire exposed dentin. Then, using a diamond disk perpendicular to the bonding interface, 'sticks' with 0.25 mm2 rectangular cross-sectional area were obtained and subjected to tensile force. RESULTS All tests ranked the adhesives in the same order. Mean values obtained by the micro-tensile test were not statistically different. For shear and tensile tests, Single Bond gave higher bond strength than Etch & Prime 3.0 (p < 0.05). Scotchbond Multi-Purpose Plus originated bondings that were statistically similar to both Single Bond and Etch & Prime 3.0. Comparing the three tests, a higher mean (p < 0.05) and a smaller coefficient of variation were found with the micro-tensile test. SIGNIFICANCE The one-bottle adhesive system obtained higher bond strength values than the self-etching adhesive upon shear and tensile strength tests. Depending on the test applied, differences among materials may not be disclosed.
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Affiliation(s)
- P E Cardoso
- Department of Dental Materials, School of Dentistry, University of Sao Paulo, Brazil
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Machado MI, Milder RV, Pacheco RS, Silva M, Braga RR, Lainson R. Naturally acquired infections with Leishmania enriettii Muniz and Medina 1948 in guinea-pigs from São Paulo, Brazil. Parasitology 1994; 109 ( Pt 2):135-8. [PMID: 8084659 DOI: 10.1017/s0031182000076241] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Two domestic guinea-pigs (Cavia porcellus), bought in Pinheros, São Paulo State, Brazil, were taken by their owners to a farm in the rural district of Capão Bonito, close to the Atlantic Forest, São Paulo, where they both developed tumour-like and ulcerating lesions on the ears. The causative agent was identified as Leishmania (L.) enriettii, based on biological characters and isoenzyme profiles. Sources of the parasite in wild mammals, and the possible sandfly vector species are discussed.
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Affiliation(s)
- M I Machado
- Disciplina de Parsitologia, Universidade Federal de Uberlândia, Minas Gerais, Brazil
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Lainson R, Shaw JJ, Silveira FT, de Souza AA, Braga RR, Ishikawa EA. The dermal leishmaniases of Brazil, with special reference to the eco-epidemiology of the disease in Amazonia. Mem Inst Oswaldo Cruz 1994; 89:435-43. [PMID: 7476229 DOI: 10.1590/s0074-02761994000300027] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Six species of Leishmania are at present known to cause cutaneous and/or mucocutaneous leishmaniasis in Brazil, and they are all to be found in the Amazon region of this country. The eco-epidemiology of each is discussed, with the observation that the Amazonian leishmaniases are all zoonoses, with their source in silvatic mammals and phlebotomine sandfly vectors. With man's destruction of the natural forest in southern Brazil, some sandfly species have survived by adapting to a peridomestic or domiciliary habitat in rural areas. Some domestic animals, such as dogs and equines are seemingly now involved in the epidemiology of the disease. No such process has yet been reported in the Amazon region, but may well take place with the continuing devastation of its forest.
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Affiliation(s)
- R Lainson
- Seção de Parasitologia, Instituto Evandro Chagas, Belém, PA, Brasil
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Silveira FT, Lainson R, Shaw JJ, De Souza AA, Ishikawa EA, Braga RR. Cutaneous leishmaniasis due to Leishmania (Leishmania) amazonensis in Amazonian Brazil, and the significance of a negative Montenegro skin-test in human infections. Trans R Soc Trop Med Hyg 1991; 85:735-8. [PMID: 1801340 DOI: 10.1016/0035-9203(91)90437-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The clinical and epidemiological features of 62 cases of cutaneous leishmaniasis due to Leishmania (Leishmania) amazonensis, from Pará State, Amazonian Brazil, are discussed. The parasite, isolated in hamster skin and/or blood-agar culture medium, was in each case identified by both biological characteristics and a monoclonal antibody specific for promastigotes of L. (L.) amazonensis. Of the 62 patients, 46 (74.2%) presented with a single cutaneous lesion, and on no occasion was evidence found indicating metastatic spread to either the naso-pharyngeal mucosae or the viscera. Recent claims that this parasite may be responsible for both mucocutaneous leishmaniasis and typical visceral leishmaniasis are discussed. Meglumine antimoniate (Glucantime) proved highly efficient in the treatment of all patients. Of the 62 patients examined by the Montenegro skin test, only 32 (51.6%) gave a positive reaction. The significance of this finding is considered and the hypothesis made that the parasite itself may induce an immunoinhibition. Field studies amply confirmed the role of Lutzomyia flaviscutellata as the major sandfly vector of L. (L.) amazonensis in Amazonia.
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Affiliation(s)
- F T Silveira
- Instituto Evandro Chagas (FNS), Belém, Pará, Brazil
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Shaw JJ, Braga RR, Lainson R, Ishikawa EA. Aconitate hydratase (ACON), an enzyme that distinguishes Leishmania of the subgenus Viannia from other trypanosomatids. Trans R Soc Trop Med Hyg 1991; 85:597-8. [PMID: 1780985 DOI: 10.1016/0035-9203(91)90358-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- J J Shaw
- Wellcome Parasitology Unit, Instituto Evandro Chagas, Belém, Pará, Brazil
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Silveira FT, Souza AA, Lainson R, Shaw JJ, Braga RR, Ishikawa EE. Cutaneous leishmaniasis in the Amazon region: natural infection of the sandfly Lutzomyia ubiquitalis (Psychodidae: Phlebotominae) by Leishmania (Viannia) Lainsoni in Pará State, Brazil. Mem Inst Oswaldo Cruz 1991; 86:127-30. [PMID: 1842393 DOI: 10.1590/s0074-02761991000100021] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2023] Open
Affiliation(s)
- F T Silveira
- Seção de Parasitologia, Instituto Evandro Chagas, Fundação Nacional de Saúde, Belém, PA, Brasil
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Silveira FT, Lainson R, Shaw JJ, Braga RR, Ishikawa EE, Souza AA. [Cutaneous leishmaniasis in Amazonia: isolation of Leishmania (Viannia) lainsoni from the rodent Agouti paca (Rodentia: Dasyproctidae), in the state of Pará, Brazil]. Rev Inst Med Trop Sao Paulo 1991; 33:18-22. [PMID: 1843391 DOI: 10.1590/s0036-46651991000100004] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The isolation of Leishmania (V.) lainsoni is recorded for the first time from a wild animal, the rodent Agouti paca (Rodentia: Dasyproctidae), from Pará State, north Brazil. Isolates of the parasite were made from apparently normal skin of 3 specimens of this rodent captured on the Island of Tocantins, in the municipality of Tucuruí, an area subsequently flooded in the formation of the lake associated with the Tucuruí hydroelectric dam. No isolations were made from the viscera. Identification of the parasite was in each case based on morphology of the amastigotes and promastigotes, behavior of the organism in hamsters, isoenzymes profiles and the use of monoclonal antibodies. The inapparent nature of the infection leads us to suggest that the "paca", Agouti paca, represents a primitive host of L. (V.) lainsoni in the Amazon Region.
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Affiliation(s)
- F T Silveira
- Instituto Evandro Chagas, Seção de Parasitologia (F.N.S.), Belém, Pará, Brasil
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Shaw JJ, Ishikawa EA, Lainson R, Braga RR, Silveira FT. Cutaneous leishmaniasis of man due to Leishmania (Viannia) shawi Lainson, de Souza, Póvoa, Ishikawa & Silveira, in Pará State, Brazil. Ann Parasitol Hum Comp 1991; 66:243-6. [PMID: 1822654 DOI: 10.1051/parasite/1991666243] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Leishmania (Viannia) shawi Lainson, Braga, de Souza, Póvoa, Ishikawa & Silveira, 1989, was originally recorded from monkeys (Cebus apella and Chiropotes satanas), sloths (Choloepus didactylus and Bradypus tridactylus) and coatis (Nasua nasua) and the sandfly, Lutzomyia whitmani. With a panel of Leishmania specific monoclonal antibodies, it was found that 30.5% of the Leishmania strains from patients, who had contracted cutaneous leishmaniasis in Pará State, were similar, but not identical to L. (V.) guyanensis. The enzyme profiles of 18 of these strains were determined, and it was found that 12 isolates belonged to the same zymodeme as the type strain of L. (V.) shawi. The other 6 belonged to a second L. (V.) shawi zymodeme that only differed from the other by having a slightly faster PEP band. These results are the first records of infections of L. (V.) shawi in man and suggest that this parasite is probably common in areas of Pará State to the south of the Amazon River.
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Affiliation(s)
- J J Shaw
- Wellcome Parasitology Unit, Belém, Pará, Brazil
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Silveira FT, Lainson R, Shaw JJ, Garcez LM, Souza AA, Braga RR, Ishikawa EA. [Experimental skin leishmaniasis: II--course of the infection in the Cebus apella primate (Cebidae) caused by Leishmania (V.) braziliensis and L. (L.) amazonensis]. Rev Soc Bras Med Trop 1990; 23:5-12. [PMID: 2089483 DOI: 10.1590/s0037-86821990000100002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
As a means of assessing the usefulness of the monkey Cebus apella as an experimental model for the study of cutaneous leishmaniasis, 5 of these animals were inoculated intradermally at 8 sites along the tail with 3 X 10(6) promastigotes of L. (V.) braziliensis, while a further 5 monkeys received similar inoculations with 3 X 10(6) promastigotes of L. (L.) amazonensis. Following the inoculations, weekly examinations and monthly biopsies showed evolution of resulting skin lesions to be as follows: a) L. (V.) braziliensis: lesions were first visible 15-20 days post-inoculation (p.i), and at 30 days they were clearly of an erythematous-papular nature, which assumed a nodular form at 60 days; after 3 months a spontaneous ulceration of these lesions was noted and, at 4 months, the initiation of healing. In one animal total healing was apparent 5 months p.i; in two others at 6 months, in another monkey after 7 months, and in the last animal at 10 months p.i. Amastigotes were demonstrated in smears from the lesions of all monkeys up to 90 days p.i; up to 120 days in two animals, and at 180 days p.i. in the monkey which showed resolution of the lesions after 10 months. b) L. (L.) amazonensis lesions were first apparent after 20 days p.i; at 30 days they were of an erythematous-papular nature, developing into nodules at 60 days. From the third month of infection onwards, however, the lesions diminished rapidly and, at 90 days p.i. amastigotes were no longer detectable in the skin.(ABSTRACT TRUNCATED AT 250 WORDS)
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Silveira FT, Lainson R, Shaw JJ, Ishikawa EA, Souza AA, Braga RR. [Sensitivity of the culture of circulating leukocytes in the detection of Leishmania in the peripheral blood of patients with tegumentary leishmaniasis]. Rev Soc Bras Med Trop 1989; 22:143-6. [PMID: 2486526 DOI: 10.1590/s0037-86821989000300006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The possible presence of Leishmania in the peripheral blood of 60 patients with American cutaneous leishmaniasis was investigated by the culture of circulating leucocytes. Patients were selected with a variety of clinical forms of the disease and in different evolutionary stages of infection. Biopsies of skin and/or mucosal lesions were made in order to isolate the parasites, which were identified using monoclonal antibodies. 40 isolations were obtained, including 5 of Leishmania (Viannia) braziliensis, 3 L. (V.) guyanesis, 1 L. (V.) lainsoni, 13 L. (Leishmania) amazonensis and 18 which could only be identified as parasites of the braziliensis complex. Cultures of circulanting leucocytes were consistently negative, and the authors conclude that this method is of little use in diagnosis of cutaneous or mucocutaneous leishmaniasis.
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Silveira FT, Lainson R, Shaw JJ, Garcez LM, Souza AA, Braga RR, Ishikawa EA. [Experimental cutaneous leishmaniasis: I--on the susceptibility of the primate Cebus apella (Cebidae) to the infection caused by Leishmania (Viannia) lainsoni Silveira, Shaw and Ishikawa, 1987]. Rev Soc Bras Med Trop 1989; 22:125-30. [PMID: 2486523 DOI: 10.1590/s0037-86821989000300003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The susceptibility of the monkey Cebus apella (Cebidae) to experimental infection by Leishmania (Viannia) lainsoni has been investigated. For this purpose, five young monkeys, 2 males and 3 females, were intradermally, inoculated, in eight different places along the dorsal surface of the tail with 3 x 10(6) promastigotes of the parasite (MHOM/BR/81/M6426, Benevides, Pará), from stationary phase culture in Difco B45 medium. After inoculations, infection in the monkeys was indicated by the presence of amastigotes in the skin lesions produced in these animals at the points of inoculation, confirming the susceptibility of the monkey Cebus apella to experimental infection by Leishmania lainsoni, with an infection period of four months. This represents a suitable period for testing antileishmanial drugs or studying the pathogenesis of the disease caused by this parasite.
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Lainson R, Braga RR, De Souza AA, Pôvoa MM, Ishikawa EA, Silveira FT. Leishmania (Viannia) shawi sp. n., a parasite of monkeys, sloths and procyonids in Amazonian Brazil. Ann Parasitol Hum Comp 1989; 64:200-7. [PMID: 2504099 DOI: 10.1051/parasite/1989643200] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Leishmania (Viannia) shawi sp. n., is described from the monkeys Cebus apella and Chiropotes satanus, the sloths Choloepus didactylus and Bradypus tridactylus, the procyonid Nasua nasua, and the phlebotomine sandfly Lutzomyia whitmani, all from primary forest in the State of Pará, north Brazil. L. (V.) shawi is variably distinguished from all other known species within the subgenus Viannia by a combination of biological, biochemical and serological characters, as revealed by studies on morphology, isoenzyme profiles, kDNA buoyant densities and monoclonal antibodies.
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Affiliation(s)
- R Lainson
- Wellcome Parasitology Unit, Pará, Brazil
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Lainson R, Shaw JJ, Braga RR, Ishikawa EA, Souza AA, Silveira FT. Isolation of Leishmania from monkeys in the Amazon Region of Brazil. Trans R Soc Trop Med Hyg 1988; 82:231. [PMID: 3142112 DOI: 10.1016/0035-9203(88)90424-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- R Lainson
- Wellcome Parasitology Unit, Instituto Evandro Chagas, F. SESP, Belém, Pará, Brazil
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Silveira FT, Shaw JJ, Braga RR, Ishikawa E. Dermal leishmaniasis in the Amazon region of Brazil: Leishmania (Viannaia) lainsoni sp.n., a new parasite from the State of Pará. Mem Inst Oswaldo Cruz 1987; 82:289-91. [PMID: 3506634 DOI: 10.1590/s0074-02761987000200018] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Affiliation(s)
- F T Silveira
- Instituto Evandro Chagas, Departamento de Parasitologia, Belém, PA, Brasil
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Affiliation(s)
- R Lainson
- Wellcome Parasitology Unit, Instituto Evandro Chagas, Belém, Pará, Brazil
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Shaw JJ, Lainson R, Ryan L, Braga RR, McMahon-Pratt D, David JR. Leishmaniasis in Brazil: XXIII. The identification of Leishmania braziliensis braziliensis in wild-caught neotropical sandflies using monoclonal antibodies. Trans R Soc Trop Med Hyg 1987; 81:69-72. [PMID: 3445325 DOI: 10.1016/0035-9203(87)90287-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Using the indirect immunofluorescence test natural flagellate infections of wild-caught sandflies, from the Serra dos Carajás region of Pará State, Brazil, were identified by sequentially staining smears made from the infected flies with monoclonal antibodies. With normal methods of isolation 30% of the infections were identifiable, but when monoclonal antibodies specific to Leishmania braziliensis braziliensis were used a further 26% were identified. The staining of organisms in smears of natural infections was different from that seen with culture forms and with forms from experimentally infected wild flies. A monoclonal antibody previously thought to be specific for Leishmania did not react with culture forms of Endotrypanum, but did react with those of monoxenous insect parasites.
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Affiliation(s)
- J J Shaw
- Wellcome Parasitology Unit, Instituto Evandro Chagas, Belém, Pará, Brazil
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Braga RR, Lainson R, Shaw JJ, Ryan L, Silveira FT. Leishmaniasis in Brazil. XXII: Characterization of Leishmania from man, dogs and the sandfly Lutzomyia longipalpis (Lutz & Neiva, 1912) isolated during an outbreak of visceral leishmaniasis in Santarém, Pará State. Trans R Soc Trop Med Hyg 1986; 80:143-5. [PMID: 3726975 DOI: 10.1016/0035-9203(86)90214-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
During epidemiological studies on an outbreak of visceral leishmaniasis in Santarém, Pará State, north Brazil, isolates of Leishmania from two children, three dogs and six naturally infected specimens of the sandfly Lutzomyia longipalpis were compared, biochemically, by starch-gel enzyme electrophoresis. They have proved to be indistinguishable from each other, and from a reference strain of Leishmania chagasi Cunha & Chagas, 1937 from a case of human visceral leishmaniasis from Bahia State, north-east Brazil, on their enzyme profiles for ASAT, ALAT, PGM, GPI, MDH and MPI. Lu. longipalpis is the principal, and possibly the only vector to man in the Amazon Region of Brazil.
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