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1.
J Helminthol ; 94: e97, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31679527

RESUMO

Several factors influence the dynamics and structure of parasite communities. Our goal was to investigate how the community composition, prevalence and abundance of parasites change across seven populations of the exotic lizard Hemidactylus mabouia in Northeast Brazil, and to describe ontogenetic and sex variations. We found differences in the composition of component communities and patterns of infection according to the host body size across the lizard populations. We did not find any variation between the sexes regarding epidemiological patterns, which can probably be explained by the similar diet and habitat use of male and female H. mabouia. An unusually high abundance and prevalence of trematodes infecting this host lizard was apparent when we compared other native lizard hosts, and we suggest that local environmental conditions might be advantageous to the development and life cycle of these parasites due to the abundance of all the intermediate and definitive hosts.


Assuntos
Lagartos/parasitologia , Parasitos/isolamento & purificação , Doenças Parasitárias em Animais/parasitologia , Animais , Tamanho Corporal , Brasil/epidemiologia , Ecossistema , Feminino , Lagartos/classificação , Lagartos/crescimento & desenvolvimento , Masculino , Parasitos/classificação , Parasitos/genética , Parasitos/fisiologia , Doenças Parasitárias em Animais/epidemiologia
2.
Eur J Prosthodont Restor Dent ; 26(3): 122-128, 2018 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-30063306

RESUMO

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.


Assuntos
Fosfatos de Cálcio/química , Resinas Compostas/química , Esmalte Dentário/efeitos dos fármacos , Materiais Dentários/química , Animais , Bovinos , Cárie Dentária/terapia , Esmalte Dentário/patologia , Dureza , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Teste de Materiais , Nanopartículas , Propriedades de Superfície
3.
Int Endod J ; 48(1): 89-94, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24646329

RESUMO

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.


Assuntos
Compostos de Alumínio/química , Compostos de Cálcio/química , Hidróxido de Cálcio/química , Capeamento da Polpa Dentária/métodos , Íons/química , Minerais/química , Óxidos/química , Agentes de Capeamento da Polpa Dentária e Pulpectomia/química , Silicatos/química , Bismuto , Força Compressiva , Análise do Estresse Dentário , Combinação de Medicamentos , Módulo de Elasticidade , Concentração de Íons de Hidrogênio , Espectrofotometria Atômica
4.
Int Endod J ; 48(8): 768-73, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25156123

RESUMO

AIM: To use computerized microtomography (micro-CT) to evaluate the efficacy of passive ultrasonic irrigation (PUI), with or without an additional file (F5), in removing calcium hydroxide medication. METHODOLOGY: The root canals of single-rooted human teeth were prepared with a ProTaper(®) F4 file (Dentsply Maillefer) and filled with calcium hydroxide/propylene glycol 400 paste. After 30 days of storage under 100% humidity, the teeth were divided into four groups (n = 8) according to the removal technique: passive ultrasonic irrigation (PUI) only, additional file only (file F5), PUI + additional file and master apical file only (F4, control). The specimens were scanned (SkyScan 1174, resolution: 14.36 µm) after chemomechanical preparation, 30 days after the application of Ca(OH)2 paste and following its removal. The percentage of medicament remaining was calculated in terms of total canal volume and medicament volume after storage, based on microtomographic images. Data were analysed using three-way anova/Tukey's test or Kruskal-Wallis/Student-Newman-Keuls test (alpha: 5%). RESULTS: The use of PUI resulted in lower Ca(OH)2 residue volumes (3.7%) compared to when PUI was not used (6.4%; P < 0.001). The use of the additional file did not significantly influence the percentage of remaining Ca(OH)2 . The percentage of Ca(OH)2 residue was greater in the apical region (6.4%) than in the cervical region (3.8%; P < 0.01). CONCLUSIONS: The use of PUI resulted in more effective Ca(OH)2 paste removal relative to the control regardless of the use of the additional file. The apical region had the highest residue volumes in all techniques.


Assuntos
Hidróxido de Cálcio/química , Materiais Restauradores do Canal Radicular/química , Irrigação Terapêutica/métodos , Ultrassom , Humanos , Técnicas In Vitro , Propilenoglicol/química , Fatores de Tempo , Microtomografia por Raio-X
6.
J Fish Biol ; 85(2): 246-63, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24919949

RESUMO

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.


Assuntos
Dieta , Cadeia Alimentar , Tubarões , Animais , Brasil , Ecossistema , Comportamento Predatório , Tubarões/classificação , Especificidade da Espécie
7.
J Dent Res ; 103(4): 427-433, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38284313

RESUMO

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.


Assuntos
Resinas Compostas , Metacrilatos , Resinas Compostas/química , Teste de Materiais , Metacrilatos/química , Fosfatos de Cálcio/química , Água , Cálcio
8.
Acta Physiol (Oxf) ; 240(3): e14111, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38314948

RESUMO

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.


Assuntos
Cafeína , Músculo Esquelético , Camundongos , Animais , Cafeína/farmacologia , Músculo Esquelético/metabolismo , Camundongos Endogâmicos C57BL , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Regeneração
9.
Oper Dent ; 45(3): E114-E123, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32053454

RESUMO

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.


Assuntos
Esmalte Dentário , Cimentos de Ionômeros de Vidro , Materiais Dentários , Dentina , Saliva Artificial , Escovação Dentária
10.
Oper Dent ; 45(3): E141-E155, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32053458

RESUMO

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.


Assuntos
Lâmpadas de Polimerização Dentária , Cura Luminosa de Adesivos Dentários , Resinas Compostas , Materiais Dentários , Dureza , Humanos , Teste de Materiais , Dente Molar , Polimerização , Propriedades de Superfície
11.
Oper Dent ; 45(6): E308-E316, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32516396

RESUMO

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.


Assuntos
Materiais Dentários , Cimentos de Resina , Resinas Compostas , Cimentos Dentários , Análise do Estresse Dentário , Teste de Materiais , Polimerização
12.
Int Endod J ; 42(10): 867-73, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19751288

RESUMO

AIM: To compare two resin-based root canal sealers (AH Plus and dual cure Epiphany) in terms of flow, polymerization stress and bond strength to dentine. METHODOLOGY: Flow was evaluated by measuring the diameter of uncured discs of sealer (0.5 mL) after 7 min compression (20N) between two glass plates (n = 5). Polymerization stress was monitored for 60 min in 1-mm thick discs bonded to two glass rods (Ø = 5 mm) attached to a universal testing machine (n = 3). Bond strength was analyzed through micropush-out test (n = 10) and failure mode was examined with scanning electron microscope (100x and 2500x). Data were statistically analyzed using the Student's t-test (alpha = 0.05). RESULTS: Polymerization stress was 0.32 +/- 0.07 MPa for Epiphany self-cure, 0.65 +/- 0.08 MPa for Epiphany light-cure and zero for AH Plus (P < 0.05). Flow data and bond strength values were 30.9 +/- 1.1, 28.6 +/- 0.7 mm and 6.3 +/- 5.3, 17.8 +/- 7.5 MPa for Epiphany and AH Plus, respectively (P < 0.001). Failure mode was predominantly cohesive in the sealer for both materials. CONCLUSIONS: Epiphany had higher flow and polymerization stress and lower bond strength values to dentine than AH Plus. In view of these findings it can be implied that AH Plus would provide a better seal.


Assuntos
Colagem Dentária , Dentina/ultraestrutura , Cimentos de Resina/química , Materiais Restauradores do Canal Radicular/química , Análise do Estresse Dentário/instrumentação , Resinas Epóxi/química , Humanos , Teste de Materiais , Metacrilatos/química , Microscopia Eletrônica de Varredura , Polímeros/química , Reologia , Estresse Mecânico , Propriedades de Superfície
13.
J Dent Res ; 87(4): 367-71, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18362321

RESUMO

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).


Assuntos
Resinas Compostas/química , Materiais Dentários/química , Metacrilatos/química , Bis-Fenol A-Glicidil Metacrilato/química , Varredura Diferencial de Calorimetria , Elasticidade , Humanos , Teste de Materiais , Maleabilidade , Polietilenoglicóis/química , Polímeros/química , Ácidos Polimetacrílicos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração
14.
Vet Parasitol ; 154(1-2): 167-70, 2008 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-18423877

RESUMO

Medicinal plants have been investigated for their anthelmintic properties and shown to be effective against eggs and larvae of gastrointestinal nematodes. The aim of this study was to evaluate the efficacy of the Lippia sidoides essential oil (LsEO) on sheep gastrointestinal nematodes. Initially, 44 naturally infected sheep were divided and treated with 200 microg kg(-1) ivermectin and 230 and 283 mg kg(-1) LsEO, respectively, plus the control. Fecal samples were collected from each animal to determine epg at 7, 14 and 21 days after treatment. In another test, 21 sheep were distributed and treated with 200 microg kg(-1) ivermectin, 283 mg kg(-1) LsEO and the control, respectively. Seven days after treatment, they were euthanized and necropsied to count and identify the nematodes from the abomasum, small and large intestines. In the first test, the efficacy of 230 and 283 mg kg(-1) LsEO and ivermectin was 38%, 45.9% and 40.2%, respectively, 7 days after treatment, and 30%, 54% and 39.6%, respectively, 14 days after treatment. In the second experiment, the respective efficacy of 283 mg kg(-1) LsEO and ivermectin was 56.9% and 34.4% against Haemonchus spp., and 39.3% and 63.6% against Trichostrongylus spp.


Assuntos
Anti-Helmínticos/uso terapêutico , Lippia/química , Infecções por Nematoides/veterinária , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Doenças dos Ovinos/tratamento farmacológico , Animais , Fezes/parasitologia , Gastroenteropatias/tratamento farmacológico , Gastroenteropatias/parasitologia , Gastroenteropatias/veterinária , Ivermectina/uso terapêutico , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/parasitologia , Óleos Voláteis/química , Contagem de Ovos de Parasitas , Óleos de Plantas/química , Ovinos
15.
J Biomed Mater Res B Appl Biomater ; 82(1): 89-92, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17078082

RESUMO

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.


Assuntos
Resinas Compostas/química , Resinas Compostas/efeitos da radiação , Etanol/química , Luz , Água/química , Teste de Materiais , Fotoquímica , Maleabilidade , Resistência à Tração
16.
Vet Parasitol ; 148(3-4): 288-94, 2007 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-17629623

RESUMO

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.


Assuntos
Anti-Helmínticos/farmacologia , Croton/química , Lippia/química , Nematoides/efeitos dos fármacos , Óleos Voláteis/farmacologia , Derivados de Alilbenzenos , Animais , Anisóis/farmacologia , Feminino , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Dose Letal Mediana , Camundongos , Nematoides/crescimento & desenvolvimento , Infecções por Nematoides/parasitologia , Óvulo/efeitos dos fármacos , Óleos de Plantas/farmacologia , Distribuição Aleatória , Timol/farmacologia
17.
Vet Parasitol ; 227: 20-5, 2016 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-27523932

RESUMO

The objective of this paper was to investigate prevalence and parasite load of the trematode Platynosomum fastosum infection and the risk of developing cholangitis/cholangiohepatitis among infected domestic cats in a city of northeastern Brazil, and to characterize the influence of fluke burden in the formation of lesions in liver and gallbladder. A total of 141 cats was necropsied and examined for the presence of P. fastosum. The observed prevalence was 42.6% (60/141, 95% CI=34.2-50.9). Parasite load varied from 1 to 219 flukes per animal. Adult cats were more frequently infected than kittens (p<0.01). Risk of cholangitis was about three times higher in infected animals (RR=3.23, 95% CI=2.01-5.07, p<0.01). Centrolobular congestion, portal cholangitis and cholestasis was significantly more common in infected as compared to non-infected cats (p<0.01). Similarly, fibrosis, cholangitis and mucous gland hyperplasia were significantly more prevalent in the bile duct of infected animals (p<0.01). Mild fibrosis and cholecystitis were observed principally in infected cats. Hyperplastic precursor lesions of cholangiocarcinoma were observed, but no solid tumor was diagnosed. These results reveal high prevalence of P. fastosum in free roaming cats in northeastern Brazil, with increased risk of liver disease.


Assuntos
Doenças do Gato/parasitologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Brasil/epidemiologia , Doenças do Gato/epidemiologia , Gatos , Feminino , Doenças da Vesícula Biliar/epidemiologia , Doenças da Vesícula Biliar/parasitologia , Doenças da Vesícula Biliar/veterinária , Hepatopatias Parasitárias/epidemiologia , Hepatopatias Parasitárias/parasitologia , Hepatopatias Parasitárias/veterinária , Masculino , Prevalência , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia
18.
J Dent Res ; 81(2): 114-8, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11827255

RESUMO

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.


Assuntos
Resinas Compostas/química , Análise de Variância , Bis-Fenol A-Glicidil Metacrilato/química , Hidroxitolueno Butilado/química , Fenômenos Químicos , Físico-Química , Humanos , Cinética , Luz , Mercúrio , Metacrilatos/química , Fotoquímica , Polietilenoglicóis/química , Polímeros/química , Ácidos Polimetacrílicos/química , Substâncias Redutoras/química , Espectroscopia de Infravermelho com Transformada de Fourier , Estatística como Assunto , Estresse Mecânico , Propriedades de Superfície , Terpenos/química , Fatores de Tempo
19.
Trans R Soc Trop Med Hyg ; 81(1): 69-72, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3445325

RESUMO

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.


Assuntos
Leishmania braziliensis/isolamento & purificação , Leishmania/isolamento & purificação , Psychodidae/parasitologia , Animais , Anticorpos Monoclonais , Especificidade de Anticorpos , Antígenos de Protozoários/imunologia , Brasil , Leishmania braziliensis/imunologia
20.
Trans R Soc Trop Med Hyg ; 80(1): 143-5, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3726975

RESUMO

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.


Assuntos
Surtos de Doenças , Leishmania donovani/enzimologia , Leishmaniose Visceral/parasitologia , Psychodidae/parasitologia , Animais , Brasil , Criança , Cães , Eletroforese em Gel de Amido , Humanos , Isoenzimas/análise
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