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Search Results: 1 - 10 of 19610 matches for " ZAIA Alexandre Augusto "
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Análise bioquímica das metaloproteases da matriz extracelular durante atrofia experimental das glandulas salivares submandibulares em ratos
SOUZA, Ana Paula de;TREVILATTO, Paula Cristina;ZAIA, Alexandre Augusto;LINE, Sérgio Roberto Peres;
Revista de Odontologia da Universidade de S?o Paulo , 1999, DOI: 10.1590/S0103-06631999000200006
Abstract: the purpose of the present study was to analyze the expression of the major metalloproteases in normal and ligated glands. the major metalloproteases detected had a molecular weight ranging from 72 to 65 kda. the gelatinolytic activity increased progressively reaching a peak between 5 and 10 days after ligation. bands with molecular weight ranging from 92-80 kda were also detected in the capsule of the gland. the 92-80 kda enzymes were only detected 2 days after ligation. the activity of these enzymes was supressed by specific inhibitors. our results show that matrix metalloproteases play an active role in the extensive remodeling of the connective tissue that occurs during the atrophy of the submandibular gland.
Análise bioquímica das metaloproteases da matriz extracelular durante atrofia experimental das glandulas salivares submandibulares em ratos
SOUZA Ana Paula de,TREVILATTO Paula Cristina,ZAIA Alexandre Augusto,LINE Sérgio Roberto Peres
Revista de Odontologia da Universidade de S?o Paulo , 1999,
Abstract: O presente estudo teve por objetivo analisar a express o das metaloproteases da matriz extracelular durante a atrofia experimental das glandulas submandibulares em ratos, causada pela obstru o do ducto excretor principal. Os zimogramas realizados com extratos das por es internas e externas das glandulas salivares normais e ligadas mostraram que as principais enzimas gelatinolíticas possuíam pesos moleculares variando entre 72 kDa e 65 kDa. A atividade dessas enzimas aumentou progressivamente até o período entre 5 e 10 dias após a liga o, decrescendo nos períodos subseqüentes. Foram também detectadas bandas migrando entre 92 kDa e 72 kDa, sendo essas enzimas detectadas em quantidades significativas apenas na regi o da cápsula da glandula, no período de 2 dias. A confirma o de que as enzimas detectadas eram metaloproteases foi feita pelo uso de inibidores específicos. Os resultados sugerem que as metaloproteases da matriz têm um papel importante na remodela o da matriz extracelular durante a atrofia experimental da glandula submandibular.
Influence of the apical enlargement size on the endotoxin level reduction of dental root canals
Ariane Cassia Salustiano Marinho,Frederico Canato Martinho,Alexandre Augusto Zaia,Caio Cezar Randi Ferraz
Journal of Applied Oral Science , 2012,
Abstract: Gram-negative bacteria play an essential role in endodontic infections because they have virulence factors such as endotoxin. Due to its potential cytotoxic activity, special attention has been given to the removal/neutralization of this endotoxin in the root canal system. OBJECTIVE: The aim of this study was to evaluate the influence of the apical enlargement size (AES) by using rotary instruments on the endotoxin level reduction of dental root canals. MATERIAL AND METHODS: Forty root canals of the mandibular premolar teeth were used. Escherichia coli endotoxin (055: B55) was inoculated into thirty root canals. Ten teeth served as the negative control group. After the incubation period, the first endotoxin samples were collected from the root canals with a sterile/apyrogenic paper point for the analysis of the endotoxin units (EU/mL) present before instrumentation (S1). Specimen instrumentation was performed with the Mtwo rotary system in the sequence 10/.04, 15/.05, 20/.06, 25/.06, 30/.05, 35/.04 and 40/.04. To monitor the effectiveness of increasing apical enlargement on endotoxin removal, the second endotoxin samples were collected from all the root canals after instrumentation with the following instruments: #25/.06- (S2); #30/.05- (S3); # 35/.04- (S4); and #40/.04- (S5). Limulus amebocyte lysate (LAL) was used to quantify the levels of endotoxin. The results were statistically compared by using repeated measures of ANOVA with post hoc Tukey testing. RESULTS: Increasing levels of endotoxin removal was achieved by large sized apical enlargement: S2 (AES #25/.06)- 89.2%, S3 (AES #30/.05)- 95.9%, S4 (AES #35/.04)- 97.8% and S5 (AES #40/.04)- 98.2%. Substantial reduction of endotoxin content was obtained in S4 and S5 compared to S2 (p<0.05), however, the root canal preparation was not able to eliminate the endotoxin. CONCLUSIONS: Under the conditions of this study, it was concluded that the reduction of endotoxin levels of the dental root canals could be predicted by increasing the apical enlargement size.
Abstract
Emmanuel Jo?o Nogueira Leal da SILVA,Carolina Carvalho SANTOS,Alexandre Augusto ZAIA
Journal of Applied Oral Science , 2013,
Abstract: ObjectivesThe aim of the present study was to investigate the effects of root canal sealers on the cytotoxicity of 3T3 fibroblasts during a period of 5 weeks.Material and MethodsFibroblasts (3T3, 1×105 cells per well) were incubated with elutes of fresh specimens from eight root canal sealers (AH Plus, Epiphany, Endomethasone N, EndoREZ, MTA Fillapex, Pulp Canal Sealer EWT, RoekoSeal and Sealapex) and with elutes of the same specimens for 5 succeeding weeks after immersing in simulated body fluid. The cytotoxicity of all root canal sealers was determined using the MTT assay. Data were analyzed using ANOVA and Tukey's test.ResultsRoekoSeal was the only sealer that did not show any cytotoxic effects (p<0.05). All the other tested sealers exhibited severe toxicity initially (week 0). MTA Fillapex remained moderately cytotoxic after the end of experimental period. Toxicity of the other tested sealers decreased gradually over time. The evaluated root canal sealers presented varying degrees of cytotoxicity, mainly in fresh mode.ConclusionsRoekoSeal had no cytotoxic effect both freshly mixed and in the other tested time points. MTA Fillapex was associated with significantly less cell viability when compared to the other tested root canal sealers.
Influence of the apical enlargement size on the endotoxin level reduction of dental root canals
Marinho, Ariane Cassia Salustiano;Martinho, Frederico Canato;Zaia, Alexandre Augusto;Ferraz, Caio Cezar Randi;Gomes, Brenda Paula Figueiredo de Almeida;
Journal of Applied Oral Science , 2012, DOI: 10.1590/S1678-77572012000600012
Abstract: gram-negative bacteria play an essential role in endodontic infections because they have virulence factors such as endotoxin. due to its potential cytotoxic activity, special attention has been given to the removal/neutralization of this endotoxin in the root canal system. objective: the aim of this study was to evaluate the influence of the apical enlargement size (aes) by using rotary instruments on the endotoxin level reduction of dental root canals. material and methods: forty root canals of the mandibular premolar teeth were used. escherichia coli endotoxin (055: b55) was inoculated into thirty root canals. ten teeth served as the negative control group. after the incubation period, the first endotoxin samples were collected from the root canals with a sterile/apyrogenic paper point for the analysis of the endotoxin units (eu/ml) present before instrumentation (s1). specimen instrumentation was performed with the mtwo? rotary system in the sequence 10/.04, 15/.05, 20/.06, 25/.06, 30/.05, 35/.04 and 40/.04. to monitor the effectiveness of increasing apical enlargement on endotoxin removal, the second endotoxin samples were collected from all the root canals after instrumentation with the following instruments: #25/.06- (s2); #30/.05- (s3); # 35/.04- (s4); and #40/.04- (s5). limulus amebocyte lysate (lal) was used to quantify the levels of endotoxin. the results were statistically compared by using repeated measures of anova with post hoc tukey testing. results: increasing levels of endotoxin removal was achieved by large sized apical enlargement: s2 (aes #25/.06)- 89.2%, s3 (aes #30/.05)- 95.9%, s4 (aes #35/.04)- 97.8% and s5 (aes #40/.04)- 98.2%. substantial reduction of endotoxin content was obtained in s4 and s5 compared to s2 (p<0.05), however, the root canal preparation was not able to eliminate the endotoxin. conclusions: under the conditions of this study, it was concluded that the reduction of endotoxin levels of the dental root canals could be predicted
The origin of life and the prebiotic chemistry
Dimas Augusto Morozin Zaia
Semina : Ciências Exatas e Tecnológicas , 2004,
Abstract: In the present paper, a historical view from Oparin-Haldane hypothesis to prebiotic chemistry is discussed. Several aspects of prebiotic chemistry are also discussed such as: environments where the abiotic synthesis of biomolecules and biopolymers could be occurred, primitive metabolism and genetic code, selection of L-amino acids and panspermia.
Antimicrobial effect and pH of chlorhexidine gel and calcium hydroxide alone and associated with other materials
Souza-Filho, Francisco José de;Soares, Adriana de Jesus;Vianna, Morgana Eli;Zaia, Alexandre Augusto;Ferraz, Caio Cezar Randi;Gomes, Brenda Paula Figueiredo de Almeida;
Brazilian Dental Journal , 2008, DOI: 10.1590/S0103-64402008000100005
Abstract: the purposes of this study were to evaluate the effectiveness of 2% chlorhexidine (chx) gluconate gel, calcium hydroxide [ca(oh)2] and their combination with iodoform and zinc oxide powder as intracanal medications against select microorganisms, and to measure the ph changes caused by these medications. antimicrobial activity was determined by the agar diffusion method. the zones of growth inhibition were measured and the results were analyzed statistically by kruskal-wallis test (p<0.05). the ph of the pastes was measured right after preparation, after 24 h and 1 week later. the largest mean zones of microbial inhibition were produced by 2% chx gel, followed by ca(oh)2 + 2% chx gel + iodoform, ca(oh)2 + 2% chx gel, ca(oh)2 + 2% chx gel + zinc oxide, and ca(oh)2 + water. the mean ph of all medications stayed above 12.0 during the whole experiment, except for chx gel (ph=7.0). the results of this study showed that all medications had antimicrobial activity, but the most effective against the tested microorganisms were 2% chx gel, followed by its combination with ca(oh)2 and iodoform.
Concentration of hydrogen ions in several calcium hydroxide pastes over different periods of time
Vianna, Morgana Eli;Zilio, Danila M.;Ferraz, Caio Cezar Randi;Zaia, Alexandre Augusto;Souza-Filho, Francisco José de;Gomes, Brenda Paula Figueiredo de Almeida;
Brazilian Dental Journal , 2009, DOI: 10.1590/S0103-64402009000500005
Abstract: the purpose of this in vitro study was to measure the concentration of hydrogen ions (ph) of calcium hydroxide [(ca(oh)2] pastes combined with different vehicles over 7 periods of time. the ca(oh)2 was manipulated with the following vehicles: i: sterile water; ii: iodoform plus sterile water; iii: local anesthetics (lydocaine 2% with 1: 100,000 epinephrine); iv: polyethyleneglycol; v: glycerin; vi: 2.0% chlorhexidine gel; vii: camphorated paramonochlorophenol (cmcp); viii: (cmcp) + glycerin; and ix: polyethyleneglycol plus cmcp. the pastes were made on a glass plate to toothpaste consistency and the ph was measured at the following times: 5 min, 1, 24, 48 h; 7, 14 and 28 days. the data were statistically analyzed (kruskal-wallis at p<0.05). at 5 min, 1 and 24 h, the ph of all tested pastes ranged from 13.05 to 11.16. at 48 h and 7 days the ph of all tested pastes ranged from 11.66 to 8.92. at 14 and 28 days almost all pastes had ph means lower than 10. in conclusion, the mean ph of all tested calcium hydroxide pastes decreased with the time. pastes made with aqueous vehicles (especially with sterile water), followed by oily vehicles (especially with cmcp + glycerin), held the highest ph means over the periods of time tested.
In vitro antimicrobial activity of calcium hydroxide pastes and their vehicles against selected microorganisms
Gomes, Brenda Paula Figueiredo de Almeida;Ferraz, Caio Cezar Randi;Vianna, Morgana Eli;Rosalen, Pedro Luiz;Zaia, Alexandre Augusto;Teixeira, Fabricio Batista;Souza-Filho, Francisco José de;
Brazilian Dental Journal , 2002, DOI: 10.1590/S0103-64402002000300002
Abstract: the aim of this study was to investigate in vitro the antimicrobial activity of calcium hydroxide in combination with several vehicles against some microorganisms commonly isolated from root canals. antimicrobial activity was determined by the agar diffusion method. stainless-steel cylinders were placed on each inoculated agar medium. the test medicaments and their controls were placed inside the cylinders. the zones of growth inhibition were measured and recorded after incubation for each plate and the results were analyzed statistically (anova). the in vitro antimicrobial effects of the medications were ranked from strongest to weakest as follows: ca(oh)2 + cmcp + glycerine, ca(oh)2 + cmcp, ca(oh)2 + glycerine, ca(oh)2 + anesthetic, ca(oh)2 + saline, ca(oh)2 + h2o, ca(oh)2 + polyethyleneglycol. the pastes with oily vehicles showed significantly larger mean zones of inhibition compared to those with aqueous or viscous vehicles. it was concluded that diffusion and antimicrobial activity of calcium hydroxide were affected by the type of vehicle used.
In vitro evaluation of the susceptibility of endodontic pathogens to calcium hydroxide combined with different vehicles
Vianna, Morgana Eli;Gomes, Brenda Paula Figueiredo de Almeida;Sena, Neylla Teixeira;Zaia, Alexandre Augusto;Ferraz, Caio Cezar Randi;Souza Filho, Francisco José de;
Brazilian Dental Journal , 2005, DOI: 10.1590/S0103-64402005000300001
Abstract: the aim of this study was to investigate in vitro the antimicrobial activity of calcium hydroxide [ca(oh)2] in combination with different vehicles against endodontic pathogens. for such purpose, a broth dilution test was performed. pastes were prepared with ca(oh)2 powder and the following vehicles: sterile water, glycerin, camphorated monochlorophenol (cmcp), cmcp + glycerin, polyethyleneglycol and cmcp + polyethyleneglycol. the time required for the pastes to produce negative cultures against the tested microorganisms was recorded and analyzed statistically using the kruskal wallis test at 5% significance level. timing for pastes to eliminate the aerobic and facultative anaerobic microorganisms ranged from 6 to 24 h, while strict anaerobic microorganisms were inhibited within 30 s to 5 min. microbial susceptibility, ranked from weakest to strongest, can be presented as follows: enterococcus faecalis (the most resistant microorganism), candida albicans, staphylococcus aureus, porphyromonas gingivalis, porphyromonas endodontalis and prevotella intermedia (the last two microorganisms required the same time to be eliminated). in conclusion, calcium hydroxide pastes needed more time to eliminate facultative than anaereobic microorganisms. these findings suggest that the antimicrobial property is related both to paste formulation and to microbial susceptibility.
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