Efeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciforme
Autor(a) principal: | |
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Data de Publicação: | 2018 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Biblioteca Digital de Teses e Dissertações da UFMA |
Texto Completo: | https://tedebc.ufma.br/jspui/handle/tede/tede/3184 |
Resumo: | Introduction: Hydroxyurea (HU) is the only drug used to treat sickle cell anemia (HbSS genotype) because it is able to increase hemoglobin and hematocrit rates with consequent improvement in oxygen transport in the blood and reduction of the frequency of vaso-occlusive crises. Thus, the use of the drug could have some effect on the adaptive pulp alterations (APA), commonly seen in HbSS individuals, since it is believed that the greatest susceptibility to these alterations is due to the formation of thrombi in the pulp microvasculature. The presence of alterations in maxillary bone trabeculation may also contribute to the increase of this susceptibility. Thus, the objective of this study was to investigate the effect of the use of HU (protection or risk) drug on APA, with three possible mechanisms: 1- protective effect mediated by reduction of vaso-occlusive crises; 2 - protective effect mediated by reduction of bone trabecular changes, and 3 - protective effect mediated by changes in hematological parameters (hemoglobin and hematocrit). Methods: This is a retrospective cohort study. We selected 123 HbSS individuals by simple random sampling without replacement. Exposure to HU was verified by electronic records analysis, and these individuals were subsequently allocated into 4 categories according to the time of use of HU (0-never used, 1- to 1 year of use, 2- of 1 to 2 years of use and 3- more than 2 years of use). For the diagnosis of the outcome, all subjects were submitted to periapical radiographic using the parallelism technique. The outcome variable (APA) was a dichotomous variable in which score 1 was attributed to the presence of mineralizations in the pulp chamber. To study the HU-APA effect, a theoretical model was proposed in which the following parameters were considered as mediator variables: number of vaso-occlusive crisis in the last year, changes in bone trabeculation, latent variable “Red Series”. The latent variable was formed by two hematological parameters: hemoglobin and hematocrit. Data referring to the variables number of vaso-occlusive crisis in last year, total hemoglobin and hematocrit were retrieved from electronic records. The diagnosis of the alterations of the bone trabeculate was also made through the periapical radiographs. The presence of the trabecular pattern in ladder or spider web was considered to define the presence of bone trabeculate alteration (score 1). The theoretical model of the study was tested using Modeling with Structural Equations. The level of significance was 5%. Results: The total effect of HU reduced the occurrence of APA in HbSS individuals (SFL = −0.451, p = 0.021), indicating that the longer the exposure time to the drug, lower the probability of developing APA. Although the factorial load was high and negative, the direct effect of the drug on APA was not observed (CFP = -0.451, p = 0.106). Mediating variables (number of vaso-occlusive crises, “Red Series” and alteration of bone trabeculation) had no effect on the outcome (p> 0.05). The number of vaso-occlusive crises had a direct effect on the changes in the bone trabecular pattern (CFP = 0.443, p = 0.002) of the jaws of HbSS individuals. Conclusion: We conclude that HU protects HbSS individuals from the occurrence of APA. However, the mechanism by which HU protects against the occurrence of these changes was not mediated by the variables included in the model. Thus, we speculate that the overall protective effect of HU for the outcome of this study is explained not by a single mechanism but by the accumulation of beneficial effects brought about by various known mechanisms of action of the drug. |
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SOUZA, Soraia de Fátima Carvalho251904903-00http://lattes.cnpq.br/0042423903693579NUNES, Ana Margarida Melohttp://lattes.cnpq.br/3752326786439481RIBEIRO, Cecília Cláudia Costahttp://lattes.cnpq.br/1783658679814263043885943-57http://lattes.cnpq.br/9577522194420742COSTA, Susilena Arouche2021-02-11T14:06:01Z2018-11-13COSTA, Susilena Arouche. Efeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciforme. 2018. 75 f. Dissertação (Programa de Pós-Graduação em Odontologia/CCBS) - Universidade Federal do Maranhão, São Luís, 2018.https://tedebc.ufma.br/jspui/handle/tede/tede/3184Introduction: Hydroxyurea (HU) is the only drug used to treat sickle cell anemia (HbSS genotype) because it is able to increase hemoglobin and hematocrit rates with consequent improvement in oxygen transport in the blood and reduction of the frequency of vaso-occlusive crises. Thus, the use of the drug could have some effect on the adaptive pulp alterations (APA), commonly seen in HbSS individuals, since it is believed that the greatest susceptibility to these alterations is due to the formation of thrombi in the pulp microvasculature. The presence of alterations in maxillary bone trabeculation may also contribute to the increase of this susceptibility. Thus, the objective of this study was to investigate the effect of the use of HU (protection or risk) drug on APA, with three possible mechanisms: 1- protective effect mediated by reduction of vaso-occlusive crises; 2 - protective effect mediated by reduction of bone trabecular changes, and 3 - protective effect mediated by changes in hematological parameters (hemoglobin and hematocrit). Methods: This is a retrospective cohort study. We selected 123 HbSS individuals by simple random sampling without replacement. Exposure to HU was verified by electronic records analysis, and these individuals were subsequently allocated into 4 categories according to the time of use of HU (0-never used, 1- to 1 year of use, 2- of 1 to 2 years of use and 3- more than 2 years of use). For the diagnosis of the outcome, all subjects were submitted to periapical radiographic using the parallelism technique. The outcome variable (APA) was a dichotomous variable in which score 1 was attributed to the presence of mineralizations in the pulp chamber. To study the HU-APA effect, a theoretical model was proposed in which the following parameters were considered as mediator variables: number of vaso-occlusive crisis in the last year, changes in bone trabeculation, latent variable “Red Series”. The latent variable was formed by two hematological parameters: hemoglobin and hematocrit. Data referring to the variables number of vaso-occlusive crisis in last year, total hemoglobin and hematocrit were retrieved from electronic records. The diagnosis of the alterations of the bone trabeculate was also made through the periapical radiographs. The presence of the trabecular pattern in ladder or spider web was considered to define the presence of bone trabeculate alteration (score 1). The theoretical model of the study was tested using Modeling with Structural Equations. The level of significance was 5%. Results: The total effect of HU reduced the occurrence of APA in HbSS individuals (SFL = −0.451, p = 0.021), indicating that the longer the exposure time to the drug, lower the probability of developing APA. Although the factorial load was high and negative, the direct effect of the drug on APA was not observed (CFP = -0.451, p = 0.106). Mediating variables (number of vaso-occlusive crises, “Red Series” and alteration of bone trabeculation) had no effect on the outcome (p> 0.05). The number of vaso-occlusive crises had a direct effect on the changes in the bone trabecular pattern (CFP = 0.443, p = 0.002) of the jaws of HbSS individuals. Conclusion: We conclude that HU protects HbSS individuals from the occurrence of APA. However, the mechanism by which HU protects against the occurrence of these changes was not mediated by the variables included in the model. Thus, we speculate that the overall protective effect of HU for the outcome of this study is explained not by a single mechanism but by the accumulation of beneficial effects brought about by various known mechanisms of action of the drug.Introdução: A Hidroxiuréia (HU) é o único fármaco utilizado para tratamento da anemia falciforme (genótipo HbSS) porque é capaz de aumentar as taxas de hemoglobina e hematócrito com consequente melhora do transporte de oxigênio no sangue e redução da frequência de crises vasoclusivas. Assim, a utilização do fármaco poderia desempenhar algum efeito sobre as alterações adaptativas da polpa (AAP), comumente vistas em indivíduos HbSS, já que se acredita que a maior susceptibilidade a estas alterações seja decorrente da formação de trombos na microvasculatura pulpar. A presença de alterações do trabeculado ósseo dos maxilares também pode contribuir para o aumento desta susceptibilidade. Desta forma, o objetivo deste estudo foi investigar qual o efeito da utilização do fármaco HU (proteção ou risco) sobre as AAP, com três possíveis mecanismos: 1- efeito protetor mediado pela redução das crises vasoclusivas; 2- efeito protetor mediado pela redução das alterações do trabeculado ósseo, e 3- efeito protetor mediado pela alteração de parâmetros hematológicos (hemoglobina e hematócrito). Métodos: Trata-se de um estudo de coorte retrospectivo. Foram selecionados 123 indivíduos HbSS por meio de amostragem aleatória simples sem reposição. A exposição a HU foi verificada por meio da análise dos prontuários eletrônicos e posteriormente estes indivíduos foram alocados em 4 categorias de acordo com o tempo de utilização do fármaco (0-nunca utilizou, 1- até 1 ano de utilização, 2- de 1 a 2 anos de utilização e 3- mais de 2 anos de utilização). Para o diagnóstico do desfecho, todos os indivíduos foram submetidos a tomadas radiográficas periapicais pela técnica do paralelismo. A variável desfecho (AAP) foi considerada uma variável dicotômica em que o score 1 foi atribuído à presença de mineralizações na câmara pulpar. Para estudo do efeito HU-AAP foi proposto um modelo teórico em que se considerou como variáveis mediadoras, os seguintes parâmetros: número de crises vasoclusivas no último ano, alterações do trabeculado ósseo e a variável latente “Série Vermelha”. Esta variável latente foi formada por dois parâmetros hematológicos: hemoglobina e hematócrito. Dados referentes às variáveis número de crises vasoclusivas do último ano, hemoglobina total e hematócrito foram resgatados dos prontuários eletrônicos. O diagnóstico das alterações do trabeculado ósseo também foi realizado por meio das radiografias periapicais. Foi considerado a presença do padrão trabecular em escada ou em teia de aranha para definir a presença de alteração do trabeculado ósseo (score 1). O modelo teórico do estudo foi testado por meio da Modelagem com Equações Estruturais. O nível de significância estabelecido foi de 5%. Resultados: O tempo de uso de HU apresentou efeito total significante sobre as AAP em indivíduos HbSS (CFP= -0.451, p=0.021) indicando que quanto maior o tempo de exposição ao fármaco menor a probabilidade de desenvolver AAP. Embora a carga fatorial tenha sido elevada e negativa, o efeito direto do fármaco sobre AAP não foi observado (CFP= -0.451, p=0.106). As variáveis mediadoras (número de crises vasoclusivas, “Série Vermelha” e alteração do trabeculado ósseo) não apresentaram efeito sobre o desfecho (p>0.05). O número de crises vasoclusivas apresentou efeito direto sobre as alterações do padrão trabecular ósseo (CFP=0.443, p= 0.002) dos maxilares de indivíduos HbSS. Conclusão: Concluímos que a HU protege indivíduos HbSS da ocorrência de AAP. No entanto, o mecanismo pelo qual a HU protege contra a ocorrência destas alterações não foi mediado pelas variáveis incluídas no modelo. Assim, especulamos que o efeito total protetor da HU para o desfecho deste estudo seja explicado não por um mecanismo único, mas pelo acúmulo de efeitos benéficos trazidos por vários mecanismos de ação conhecidos do fármaco.Submitted by Daniella Santos (daniella.santos@ufma.br) on 2021-02-11T14:06:01Z No. of bitstreams: 1 SusilenaCosta.pdf: 1176248 bytes, checksum: 29b6dc8d98c907752067e17522e8c102 (MD5)Made available in DSpace on 2021-02-11T14:06:01Z (GMT). No. of bitstreams: 1 SusilenaCosta.pdf: 1176248 bytes, checksum: 29b6dc8d98c907752067e17522e8c102 (MD5) Previous issue date: 2018-11-13FAPEMAapplication/pdfporUniversidade Federal do MaranhãoPROGRAMA DE PÓS-GRADUAÇÃO EM ODONTOLOGIA/CCBSUFMABrasilDEPARTAMENTO DE ODONTOLOGIA I/CCBSAnemia falciformeCalcificação pulparHidroxiuréiaPolpa dentáriaSickle-cell anemiaPulp calcificationHydroxyureaDental pulpOdontologiaEfeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciformeEffects of time of use of hydroxyurea on adaptive pulp changes in individuals with sickle cell anemiainfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Biblioteca Digital de Teses e Dissertações da UFMAinstname:Universidade Federal do Maranhão (UFMA)instacron:UFMAORIGINALSusilenaCosta.pdfSusilenaCosta.pdfapplication/pdf1176248http://tedebc.ufma.br:8080/bitstream/tede/3184/2/SusilenaCosta.pdf29b6dc8d98c907752067e17522e8c102MD52LICENSElicense.txtlicense.txttext/plain; charset=utf-82255http://tedebc.ufma.br:8080/bitstream/tede/3184/1/license.txt97eeade1fce43278e63fe063657f8083MD51tede/31842021-02-11 11:06:01.038oai:tede2: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Biblioteca Digital de Teses e Dissertaçõeshttps://tedebc.ufma.br/jspui/PUBhttp://tedebc.ufma.br:8080/oai/requestrepositorio@ufma.br||repositorio@ufma.bropendoar:21312021-02-11T14:06:01Biblioteca Digital de Teses e Dissertações da UFMA - Universidade Federal do Maranhão (UFMA)false |
dc.title.por.fl_str_mv |
Efeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciforme |
dc.title.alternative.eng.fl_str_mv |
Effects of time of use of hydroxyurea on adaptive pulp changes in individuals with sickle cell anemia |
title |
Efeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciforme |
spellingShingle |
Efeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciforme COSTA, Susilena Arouche Anemia falciforme Calcificação pulpar Hidroxiuréia Polpa dentária Sickle-cell anemia Pulp calcification Hydroxyurea Dental pulp Odontologia |
title_short |
Efeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciforme |
title_full |
Efeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciforme |
title_fullStr |
Efeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciforme |
title_full_unstemmed |
Efeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciforme |
title_sort |
Efeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciforme |
author |
COSTA, Susilena Arouche |
author_facet |
COSTA, Susilena Arouche |
author_role |
author |
dc.contributor.advisor1.fl_str_mv |
SOUZA, Soraia de Fátima Carvalho |
dc.contributor.advisor1ID.fl_str_mv |
251904903-00 |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/0042423903693579 |
dc.contributor.referee1.fl_str_mv |
NUNES, Ana Margarida Melo |
dc.contributor.referee1Lattes.fl_str_mv |
http://lattes.cnpq.br/3752326786439481 |
dc.contributor.referee2.fl_str_mv |
RIBEIRO, Cecília Cláudia Costa |
dc.contributor.referee2Lattes.fl_str_mv |
http://lattes.cnpq.br/1783658679814263 |
dc.contributor.authorID.fl_str_mv |
043885943-57 |
dc.contributor.authorLattes.fl_str_mv |
http://lattes.cnpq.br/9577522194420742 |
dc.contributor.author.fl_str_mv |
COSTA, Susilena Arouche |
contributor_str_mv |
SOUZA, Soraia de Fátima Carvalho NUNES, Ana Margarida Melo RIBEIRO, Cecília Cláudia Costa |
dc.subject.por.fl_str_mv |
Anemia falciforme Calcificação pulpar Hidroxiuréia Polpa dentária |
topic |
Anemia falciforme Calcificação pulpar Hidroxiuréia Polpa dentária Sickle-cell anemia Pulp calcification Hydroxyurea Dental pulp Odontologia |
dc.subject.eng.fl_str_mv |
Sickle-cell anemia Pulp calcification Hydroxyurea Dental pulp |
dc.subject.cnpq.fl_str_mv |
Odontologia |
description |
Introduction: Hydroxyurea (HU) is the only drug used to treat sickle cell anemia (HbSS genotype) because it is able to increase hemoglobin and hematocrit rates with consequent improvement in oxygen transport in the blood and reduction of the frequency of vaso-occlusive crises. Thus, the use of the drug could have some effect on the adaptive pulp alterations (APA), commonly seen in HbSS individuals, since it is believed that the greatest susceptibility to these alterations is due to the formation of thrombi in the pulp microvasculature. The presence of alterations in maxillary bone trabeculation may also contribute to the increase of this susceptibility. Thus, the objective of this study was to investigate the effect of the use of HU (protection or risk) drug on APA, with three possible mechanisms: 1- protective effect mediated by reduction of vaso-occlusive crises; 2 - protective effect mediated by reduction of bone trabecular changes, and 3 - protective effect mediated by changes in hematological parameters (hemoglobin and hematocrit). Methods: This is a retrospective cohort study. We selected 123 HbSS individuals by simple random sampling without replacement. Exposure to HU was verified by electronic records analysis, and these individuals were subsequently allocated into 4 categories according to the time of use of HU (0-never used, 1- to 1 year of use, 2- of 1 to 2 years of use and 3- more than 2 years of use). For the diagnosis of the outcome, all subjects were submitted to periapical radiographic using the parallelism technique. The outcome variable (APA) was a dichotomous variable in which score 1 was attributed to the presence of mineralizations in the pulp chamber. To study the HU-APA effect, a theoretical model was proposed in which the following parameters were considered as mediator variables: number of vaso-occlusive crisis in the last year, changes in bone trabeculation, latent variable “Red Series”. The latent variable was formed by two hematological parameters: hemoglobin and hematocrit. Data referring to the variables number of vaso-occlusive crisis in last year, total hemoglobin and hematocrit were retrieved from electronic records. The diagnosis of the alterations of the bone trabeculate was also made through the periapical radiographs. The presence of the trabecular pattern in ladder or spider web was considered to define the presence of bone trabeculate alteration (score 1). The theoretical model of the study was tested using Modeling with Structural Equations. The level of significance was 5%. Results: The total effect of HU reduced the occurrence of APA in HbSS individuals (SFL = −0.451, p = 0.021), indicating that the longer the exposure time to the drug, lower the probability of developing APA. Although the factorial load was high and negative, the direct effect of the drug on APA was not observed (CFP = -0.451, p = 0.106). Mediating variables (number of vaso-occlusive crises, “Red Series” and alteration of bone trabeculation) had no effect on the outcome (p> 0.05). The number of vaso-occlusive crises had a direct effect on the changes in the bone trabecular pattern (CFP = 0.443, p = 0.002) of the jaws of HbSS individuals. Conclusion: We conclude that HU protects HbSS individuals from the occurrence of APA. However, the mechanism by which HU protects against the occurrence of these changes was not mediated by the variables included in the model. Thus, we speculate that the overall protective effect of HU for the outcome of this study is explained not by a single mechanism but by the accumulation of beneficial effects brought about by various known mechanisms of action of the drug. |
publishDate |
2018 |
dc.date.issued.fl_str_mv |
2018-11-13 |
dc.date.accessioned.fl_str_mv |
2021-02-11T14:06:01Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
COSTA, Susilena Arouche. Efeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciforme. 2018. 75 f. Dissertação (Programa de Pós-Graduação em Odontologia/CCBS) - Universidade Federal do Maranhão, São Luís, 2018. |
dc.identifier.uri.fl_str_mv |
https://tedebc.ufma.br/jspui/handle/tede/tede/3184 |
identifier_str_mv |
COSTA, Susilena Arouche. Efeitos do tempo de uso da hidroxiuréia sobre as alterações adaptativas da polpa em indivíduos com anemia falciforme. 2018. 75 f. Dissertação (Programa de Pós-Graduação em Odontologia/CCBS) - Universidade Federal do Maranhão, São Luís, 2018. |
url |
https://tedebc.ufma.br/jspui/handle/tede/tede/3184 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal do Maranhão |
dc.publisher.program.fl_str_mv |
PROGRAMA DE PÓS-GRADUAÇÃO EM ODONTOLOGIA/CCBS |
dc.publisher.initials.fl_str_mv |
UFMA |
dc.publisher.country.fl_str_mv |
Brasil |
dc.publisher.department.fl_str_mv |
DEPARTAMENTO DE ODONTOLOGIA I/CCBS |
publisher.none.fl_str_mv |
Universidade Federal do Maranhão |
dc.source.none.fl_str_mv |
reponame:Biblioteca Digital de Teses e Dissertações da UFMA instname:Universidade Federal do Maranhão (UFMA) instacron:UFMA |
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Universidade Federal do Maranhão (UFMA) |
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UFMA |
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UFMA |
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Biblioteca Digital de Teses e Dissertações da UFMA |
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Biblioteca Digital de Teses e Dissertações da UFMA |
bitstream.url.fl_str_mv |
http://tedebc.ufma.br:8080/bitstream/tede/3184/2/SusilenaCosta.pdf http://tedebc.ufma.br:8080/bitstream/tede/3184/1/license.txt |
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Biblioteca Digital de Teses e Dissertações da UFMA - Universidade Federal do Maranhão (UFMA) |
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repositorio@ufma.br||repositorio@ufma.br |
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1809926196255784960 |