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1.
Mater Sci Eng C Mater Biol Appl ; 99: 999-1006, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30889775

RESUMO

Tissue engineering combine biomaterials, cells and biologically active molecules having as a goal create functional tissues; many of the compositions are blends of a polymeric matrix with ceramic fillers, however, reduction of mechanical resistance can be a drawback on ceramic-polymer systems. In this manuscript, we investigate the potential of calcium-deficient hydroxyapatite (CDHA) whiskers, a needle shape bioceramic, to enhance mechanical and osteoconduction properties on the polymeric matrix. For this purpose, PCL scaffolds incorporating CDHA whiskers were produced by combining solvent casting and particulate leaching techniques to develop a composite scaffold that possess mechanical and biological properties which is useful for bone tissue engineering regeneration. We produced CDHA whiskers using alkaline hydrolysis of α-tricalcium phosphate and characterized by XRD, XRF and SEM. PCL/CDHA scaffolds were fabricated with a final porosity of ~70%, quantified by SEM images. Mechanical properties were evaluated by compression test. As an initial test, PCL/CDHA scaffolds were immersed in simulated body fluid to quantify apatite deposition. In vitro and in vivo studies were performed to assess cytotoxicity and bioactivity. CDHA whiskers exhibited a needle-like morphology and a Ca/P ratio equal to calcium deficient hydroxyapatite. The composite scaffolds contained interconnected pores 177 to 350 µm in size and homogeneous ceramic distribution. The addition of CDHA whiskers influences the mechanical results: higher elastic modulus and compressive strength was observed on PCL/CDHA samples. In vitro results demonstrated biocompatibility on PCL and PCL/CDHA films. In vivo data demonstrated cellular infiltration from the surrounding tissue with new bone formation that suggests bioactive potential of CDHA whiskers. Our goal was to produce a scaffold with a potential induction factor and a favorable morphology, which was proved according to this study's findings.


Assuntos
Osso e Ossos/fisiologia , Cálcio/química , Durapatita/química , Animais , Masculino , Poliésteres/química , Ratos Wistar , Difração de Raios X
2.
Transplant Proc ; 51(2): 595-601, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30879598

RESUMO

The recovery or collection of postmortem semen raises relevant ethical and social concerns. In this study we report 2 cases witnessed by the authors in an organ procurement organization in Brazil. The patients had a diagnosis of brain death, were organ donors, and had no consent for the use of postmortem sperm. In Brazil, the diagnosis of brain death has been clearly established since 1997, with the most recent update in 2017, but has not considered the possibility of the collection of sperm or eggs from the donor. A review of the world literature has been carried out, as well as current legislation in different countries, including Brazil, with special interest in the impact on the autonomy of the deceased (informed consent or not), the wife, the generation of the child and their rights, and the ethical role of the physician.


Assuntos
Consentimento Livre e Esclarecido/ética , Sêmen , Doadores de Tecidos/ética , Obtenção de Tecidos e Órgãos/ética , Obtenção de Tecidos e Órgãos/legislação & jurisprudência , Adulto , Morte Encefálica , Brasil , Humanos , Consentimento Livre e Esclarecido/legislação & jurisprudência , Masculino , Princípios Morais , Doadores de Tecidos/legislação & jurisprudência
3.
Injury ; 49(12): 2154-2160, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30268514

RESUMO

In traumatology, we encounter several clinical challenges that involve extensive bone loss primarily related to trauma, conditions that can be treated with autologous grafts. A good alternative is the use of synthetic biomaterials as substitutes. These polymers provide a suitable environment for the growth of new bone and vascular tissue, which are essential for repair. Collagen/hydroxyapatite composites have proven to be biocompatible and to behave mechanically. Furthermore, the addition of chitosan contributes to the formation of a three-dimensional structure that permits cell adhesion and proliferation, thus improving osteogenesis. The aim of this study was to evaluate bone formation during the repair of bone defects experimentally induced in the skull of rats and grafted with a polymer blend consisting of bovine tendon collagen and chitosan combined with hydroxyapatite. Thirty animals were used for the creation of a defect in the left parietal bone and were divided into three groups of 10 animals each: a control group without biomaterial implantation, a group receiving the blend of collagen and chitosan, and a group receiving this blend combined with hydroxyapatite. Each group was subdivided and the animals were sacrificed 3 or 8 weeks after surgery. After sacrifice, the skulls were removed for macroscopic photodocumentation and radiographic examination. The samples were processed for histological evaluation of new bone formation at the surgical site. Macroscopic and radiographic analysis demonstrated the biocompatibility of the blends. Histologically, the formation of new bone occurred in continuity with the edges of the defect, with the observation of higher volumes in the grafted groups compared to control. Mineralization of sponges did not stimulate bone neoformation, with bone repair being incomplete over the experimental period. In conclusion, mineralization by the addition of hydroxyapatite should be better studied. However, the collagen/chitosan sponges used in this study are suitable to stimulate osteogenesis in cranial defects, although this process is slow and not sufficient to achieve complete bone regeneration over a short period of time.


Assuntos
Materiais Biocompatíveis/química , Substitutos Ósseos/química , Quitosana/farmacologia , Colágeno/farmacologia , Durapatita/farmacologia , Osteogênese/fisiologia , Fraturas Cranianas/patologia , Animais , Proteína Morfogenética Óssea 2 , Adesão Celular , Proliferação de Células , Modelos Animais de Doenças , Masculino , Ratos , Ratos Wistar , Fraturas Cranianas/cirurgia
4.
Zootaxa ; 4276(1): 61-95, 2017 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-28610216

RESUMO

The apseudomorphan tanaidaceans of the deep sea have been under-studied, especially in chemosynthetic habitats. A total of ten species present in the Gulf of Cadiz and the Horseshoe Continental Rise (SW off the Iberian Peninsula) are listed here, and new distribution data, ecological remarks and description of one new species of Atlantapseudes (Atlantapseudes curvatus sp. nov.) from recent research cruises are added. Pseudosphyrapus azorensis and Francapseudes uniarticulatus are recorded for the first time since the original descriptions. Notes on morphological development of Leviapseudes segonzaci and intraspecific variation of F. uniarticulatus are included, together with illustrations and descriptions of the material from the Gulf of Cadiz to complement previous descriptions.


Assuntos
Crustáceos , Animais , Ecologia , Ecossistema
5.
Mar Environ Res ; 112(Pt A): 140-51, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26525873

RESUMO

The present study is one of the few that investigate the temporal variability of epifaunal assemblages associated with coral species, particularly the octocorals Eunicella gazella and Leptogorgia lusitanica in south Portugal. The results suggest time rather than colony size as a primary driver of the ecological patterns of these assemblages, which were dominated by amphipods, molluscs and polychaetes. Temporal variability was linked to changes in environmental parameters, namely temperature, chlorophyll a and particulate organic carbon. Hence, temporal variability must be taken into account for the design of future biodiversity assessment studies, as different patterns may be observed depending on the sampling time. Associated epifaunal assemblages were consistently dominated by resident species (i.e. species present in all sampling periods) and a peak of rare species was observed in the transition from spring to summer following the increase in seawater temperature. Turnover was particularly high in the transition between the spring and summer periods. In both hosts, turnover was higher in the small sized colonies, which harboured less diverse and less abundant assemblages that also differed from those inhabiting larger size colonies. The high levels of diversity associated with gorgonian colonies highlight the need for the conservation of this priority habitat.


Assuntos
Antozoários/fisiologia , Biodiversidade , Recifes de Corais , Animais , Clorofila/análise , Clorofila A , Portugal , Estações do Ano , Água do Mar/análise , Temperatura , Fatores de Tempo
6.
Injury ; 46(7): 1215-22, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25920373

RESUMO

The indication of biomaterials has increased substantially in the regenerative therapy of bone defects. However, in addition to evaluating the physicochemical properties of biomaterials, the quality of the recipient tissue is also essential for the osseointegration of implants, as abnormalities in bone metabolism, such as gonadal hormone deficiency, can influence bone healing. This study evaluated the osteoregenerative capacity of collagen membranes derived from bovine pericardium and intestinal serosa in the repair of cranial defects in ovariectomised rats. Thirty female Wistar rats were submitted to surgical creation of a 5-mm cranial bone defect. The rats were divided into a control group (not ovariectomised) and an ovariectomised group. The non-ovariectomised group was divided into three subgroups: control (G1) in which the defect was not filled with the biomaterial, and two subgroups (G2 and G3) that received the bovine pericardium- and serosa-derived collagen membranes, respectively. The ovariectomised group was divided into the same subgroups (G4, G5, and G6). The animals were sacrificed 8 weeks after surgery. The calvaria were removed for macroscopic and radiographic photodocumentation and processed for histomorphometric analysis of bone healing at the surgical site. Macroscopic, radiological, and microscopic analyses demonstrated the biocompatibility of the implanted collagen membranes, as indicated by the absence of infiltration and signs of inflammation at the surgical site. Histologically, discrete immature bone neoformation projecting from the margins of the defect was observed at the surgical site in ovariectomised groups when compared to the non-ovariectomised groups. The volume of newly formed bone was significantly higher in the non-ovariectomised groups (G1: 7.83%±1.32; G2: 21.33%±1.96; and G3: 22.83%±0.98) compared to the respective ovariectomised subgroups (G4: 3.16%±0.75; G5: 16.83%±0.98; and G6: 16.16%±0.75), thus demonstrating the deleterious effects of ovariectomy on bone homeostasis. Higher volumes of newly formed bone were observed in the groups receiving the membrane grafts (G2, G3, G5, and G6) compared to the control groups (G1 and G4). In conclusion, the bilateral ovariectomy compromises the ability to repair bone lesions grafted with osteoconductive biomaterials as in the case of collagen membranes derived from both bovine pericardium and intestinal serosa.


Assuntos
Materiais Biocompatíveis/farmacologia , Colágeno/farmacologia , Pericárdio/patologia , Crânio/patologia , Cicatrização/fisiologia , Animais , Bovinos , Modelos Animais de Doenças , Estudos de Viabilidade , Feminino , Ovariectomia , Ratos , Ratos Wistar , Transplante Heterólogo
7.
J Fish Biol ; 85(3): 927-32, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24976453

RESUMO

In the framework of the R.V. Nautilus exploration programme, remotely operated vehicle (ROV) surveys were conducted at bathyal depths in the Gorringe Bank. Video transects revealed the presence of the chimaerids Chimaera opalescens and Hydrolagus affinis in the region. An identification key for the north-east Atlantic species of the family Chimaeridae is proposed.


Assuntos
Peixes , Animais , Oceano Atlântico , Ecossistema
8.
Asian-Australas J Anim Sci ; 27(7): 1003-12, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25050043

RESUMO

The use of a suitable methodology to quantify the phytate phosphorus (Pphy) content in both the feed and the excreta from broilers is required to enable accurate calculation of the catalytic efficiency of the phytase supplemented in the feed. This study was conducted to compare 2 analytical methodologies (colorimetry and also high-performance liquid chromatography with a refractive index detector) in order to calculate the phytase efficiency by utilizing the results from the methodology that was shown to be the most appropriate. One hundred and twenty broilers were distributed in a (4+1)×2 factorial arrangement, corresponding to 4 diets that were equally deficient in P supplemented with increasing levels of phytase (0, 750, 1,500, and 2,250 units of phytase activity - FTU - per kg of feed) plus 1 positive control diet without phytase, supplied to male and female birds. The result indicated that the colorimetric methodology with an extraction ratio of 1:20 (mass of sample in g:volume of the solvent extractor in mL) was shown to be the most adequate. There was no interaction between the phytase level and the sex of the broilers (p>0.05). Males consumed 12% more Pphy than did females (p<0.01), but the sex of the broilers did not affect (p>0.05) the excretion and retention coefficient of Pphy. The increase in the phytase level of the diet reduced (linear, p<0.01) the Pphy excretion. The greatest Pphy retention was estimated at 87.85% when the diet contained 1,950 FTU/kg (p<0.01), indicating that it is possible to reduce the inorganic P in the formulation at an amount equivalent to 87.85% of the Pphy content present in the feed, which, in this research, corresponds to a decrease in 2.86 g of P/kg of the feed.

9.
Injury ; 44(7): 908-13, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23340234

RESUMO

Defects associated with bone mass loss are frequently treated by autogenous bone grafting. However, synthetic biomaterials such as calcium phosphate ceramics can substitute autologous grafts as long as they are biocompatible with bone tissue. In addition, low-level laser therapy (LLLT) is used to enhance bone regeneration by stimulating the local microcirculation and increasing the synthesis of collagen by bone cells. However, bone health is fundamental for osseointegration of the graft and bone repair. In this respect, excessive tobacco consumption can compromise expected outcomes because of its deleterious effects on bone metabolism that predispose to the development of osteoporosis. The objective of this study was to evaluate the regeneration of bone defects implanted with biomaterial and stimulated by LLLT in rats submitted to passive cigarette smoking. Porous hydroxyapatite granules were implanted into critical-size defects induced experimentally in the distal epiphysis of the right femur of 20 female Wistar rats submitted to passive smoking for 8 months in a smoking box. The defect site was irradiated with a gallium-arsenide laser at an intensity of 5.0 J/cm2. The animals were divided into four groups: control (non-smoking) rates submitted (G2) or not (G1) to laser irradiation, and smoking rats submitted (G4) or not (G3) to laser irradiation. The animals were sacrificed 8 weeks after biomaterial implantation. The right femurs were removed for photodocumentation, radiographed, and processed for routine histology. The results showed good radiopacity of the implant site and of the hydroxyapatite granules. Histologically, formation of new trabecular bone was observed adjacent to the hydroxyapatite granules in G1 and G2. In G3 and G4, the granules were surrounded mainly by connective tissue. In conclusion, passive smoking compromised bone neoformation in the defects and the LLLT protocol was not adequate to stimulate local osteogenesis.


Assuntos
Substitutos Ósseos , Durapatita , Osseointegração , Poluição por Fumaça de Tabaco/efeitos adversos , Animais , Modelos Animais de Doenças , Feminino , Inalação , Terapia a Laser , Osteoporose , Ratos , Ratos Wistar
10.
J Clin Immunol ; 32(4): 778-85, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22402866

RESUMO

PURPOSE: The objective of this study was to determine the frequencies of autoantibodies to heterogeneous islet-cell cytoplasmic antigens (ICA), glutamic acid decarboxylase(65) (GAD(65)A), insulinoma-associated antigen-2 (IA-2A) and insulin (IAA)-and human leukocyte antigen (HLA) class II markers (HLA-DR and -DQ) in first degree relatives of heterogeneous Brazilian patients with type I diabetes (T1DM). A major focus of this study was to determine the influence of age, gender, proband characteristics and ancestry on the prevalence of autoantibodies and HLA-DR and -DQ alleles on disease progression and genetic predisposition to T1DM among the first-degree relatives. METHODS: IAA, ICA, GAD(65)A, IA-2A and HLA- class II alleles were determined in 546 first-degree-relatives, 244 siblings, 55 offspring and 233 parents of 178 Brazilian patients with T1DM. RESULTS: Overall, 8.9% of the relatives were positive for one or more autoantibodies. IAA was the only antibody detected in parents. GAD(65) was the most prevalent antibody in offspring and siblings as compared to parents and it was the sole antibody detected in offspring. Five siblings were positive for the IA-2 antibody. A significant number (62.1%) of siblings had 1 or 2 high risk HLA haplotypes. During a 4-year follow-up study, 5 siblings (expressing HLA-DR3 or -DR4 alleles) and 1 offspring positive for GAD(65)A progressed to diabetes. CONCLUSIONS: The data indicated that the GAD(65) and IA-2 antibodies were the strongest predictors of T1DM in our study population. The high risk HLA haplotypes alone were not predictive of progression to overt diabetes.


Assuntos
Autoanticorpos/sangue , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Adolescente , Adulto , Fatores Etários , Idoso , Autoanticorpos/imunologia , Biomarcadores/sangue , Brasil , Criança , Pré-Escolar , Progressão da Doença , Família , Feminino , Predisposição Genética para Doença , Genótipo , Glutamato Descarboxilase/imunologia , Antígenos HLA-DQ/imunologia , Antígenos HLA-DR/imunologia , Humanos , Lactente , Insulina/imunologia , Masculino , Pessoa de Meia-Idade , Proteínas Tirosina Fosfatases Classe 8 Semelhantes a Receptores/imunologia , Fatores Sexuais , Adulto Jovem
11.
Int J Sports Med ; 30(12): 906-12, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19941250

RESUMO

As people age, they experience a decline in immune responses. Unusually heavy acute or chronic exercise could increase the risk of upper respiratory tract infection (URTI) whereas regular moderate physical activity may reduce URTI symptomatology. The purpose of the present study was to determine whether an aerobic exercise program would promote chronic adaptations in plasma IgA, IgG and IgM, and salivary IgA (Sal-IgA) in both elderly women and men. Forty-three independently living men and women, aged between 65 and 96 years, were randomly assigned to an aerobic exercising or a control group. Each participant underwent three evaluations (pre, post at 16 weeks and follow-up at 32 weeks). The aerobic exercise group increased resting plasma IgA concentration from 1.08 g. L (-1)+/-0.50 g. L (-1) to 2.29 g. L (-1)+/-0.93 g. L (-1), whereas salivary IgA concentration was unchanged. The control group maintained the plasma IgA values but experienced a decrease in Sal-IgA. The IgG and IgM plasma concentrations increased in both groups, however, only the exercise group maintained higher values in the final follow-up evaluation. Regular aerobic exercise may be effective in promoting IgA immunity and protecting against the deterioration in Sal-IgA values observed in the control group. No gender differences in the immunoglobulin responses to aerobic training were observed.


Assuntos
Exercício Físico , Imunoglobulina A/metabolismo , Imunoglobulina G/metabolismo , Imunoglobulina M/metabolismo , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Imunoglobulina A/sangue , Imunoglobulina A Secretora/metabolismo , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Saliva/imunologia
12.
Braz. j. morphol. sci ; 26(2): 62-67, Apr.-June. 2009.
Artigo em Inglês | LILACS | ID: lil-644253

RESUMO

It is estimated that 190 million people worldwide have diabetes mellitus. Several attempts have been made to elucidate the deleterious effects of diabetes on various organ systems, as well as the reversal of these effects by treatment and/or diet. Thus, the objective of the present study was to analyze the effects of prolonged treatment with Syzygium cumini (Jambolan) sheet aqueous extract on the structure of cells responsible for secretory processes in the parotid and submandibular salivary glands of spontaneously diabetic mice. Ten female mice, including five diabetic Nod mice (group I) and five BALB/c mice (group II), were used. After characterization of the diabetic state, animals of group I received Syzygium cumini extract and group II animals received water ad libitum. After the experimental period, the salivary glands were collected from the animals for stereological analysis. The results showed structural alterations in the salivary glands of diabetic animals characterized by nuclear and cytoplasmic atrophy and the occurrence of inflammatory cells, as well as elevated glycemia levels. We conclude that no recovery of normal glycemia levels or glandular tissue structure occurs in diabetic animals even when treated with Syzygium cumini extract, a fact that might result in changes in the functional mechanisms of these organs.


Assuntos
Animais , Feminino , Ratos , Diabetes Mellitus , Diabetes Mellitus/terapia , Glândulas Salivares/anatomia & histologia , Glândulas Salivares/fisiopatologia , Syzygium , Syzygium/administração & dosagem , Syzygium/uso terapêutico , Glândulas Salivares
13.
Diabetes Obes Metab ; 10(3): 238-45, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18269639

RESUMO

OBJECTIVES: To evaluate the effects of Metformin and Glyburide on cardiovascular, metabolic and hormonal parameters during progressive exercise performed to exhaustion in the post-prandial state in women with type 2 diabetes (T2DM). DESIGN AND METHODS: Ten T2DM patients treated with Metformin (M group), 10 with Glyburide (G group) and 10 age-paired healthy subjects exercised on a bicycle ergometer up to exercise peak. Cardiovascular and blood metabolic and hormonal parameters were measured at times -60 min, 0 min, exercise end, and at 10 and 20 minutes of recovery phase. Thirty minutes before the exercise, a standard breakfast was provided to all participants. The diabetic patients took Metformin or Glyburide before or with meal. RESULTS: Peak oxygen uptake (VO(2)) was lower in patients with diabetes. Plasma glucose levels remained unchanged, but were higher in both diabetic groups. Patients with diabetes also presented lower insulin levels after meals and higher glucagon levels at exercise peak than C group. Serum cortisol levels were higher in G than M group at exercise end and recovery phase. Lactate levels were higher in M than G group at fasting and in C group at exercise peak. Nor epinephrine, GH and FFA responses were similar in all 3 groups. CONCLUSION: Progressive exercise performed to exhaustion, in the post-prandial state did not worsen glucose control during and after exercise. The administration of the usual dose of Glyburide or Metformin to T2DM patients did not influence the cardiovascular, metabolic and hormonal response to exercise.


Assuntos
Fenômenos Fisiológicos Cardiovasculares/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Fadiga/etiologia , Glibureto/uso terapêutico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Glicemia/metabolismo , Estudos de Casos e Controles , Exercício Físico/fisiologia , Tolerância ao Exercício , Feminino , Hormônios/sangue , Humanos , Pessoa de Meia-Idade
14.
Diabet Med ; 24(6): 592-9, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17381497

RESUMO

AIMS: To compare the effects of metformin and glibenclamide on cardiovascular, metabolic and hormonal parameters during exercise of moderate intensity performed in the postprandial state, in women with Type 2 diabetes. METHODS: Ten patients treated with metformin, 10 with glibenclamide and 10 control subjects (C) exercised on a bicycle ergometer at 50% of oxygen uptake (VO(2)) peak for 45 min. Cardiovascular, blood metabolic and hormonal parameters were determined at times -60 min (fasting), 0, +15, +30, +45 min (exercise) and at +60, +90 min (recovery). Thirty minutes prior to exercise, participants consumed a standard breakfast. Patients with diabetes took metformin or glibenclamide before the meal. RESULTS: Systolic and diastolic blood pressure and plasma glucose were higher in both diabetic groups, for the whole experiment. Blood glucose did not change during exercise in the three groups and increased at recovery only in the control group. Plasma glucagon concentrations at the end of exercise and recovery, and plasma lactate concentrations at recovery were higher in the metformin group. Insulin, noradrenaline, growth hormone, cortisol and free fatty acid responses were similar in all three groups. CONCLUSIONS: Our results suggest that the usual dose of glibenclamide and metformin can be taken safely before postprandial exercise of moderate intensity without affecting cardiovascular, metabolic and hormonal responses. However, after exercise, glibenclamide and metformin prevent the normal rise in blood glucose and metformin delays the fall in plasma lactate concentrations.


Assuntos
Glicemia/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Diabetes Mellitus Tipo 2/fisiopatologia , Hormônios/sangue , Hipoglicemiantes/farmacologia , Adulto , Brasil , Estudos de Casos e Controles , Colesterol/sangue , Diabetes Mellitus Tipo 2/sangue , Exercício Físico , Feminino , Glibureto/farmacologia , Humanos , Metformina/farmacologia , Pessoa de Meia-Idade , Período Pós-Prandial
15.
J Submicrosc Cytol Pathol ; 34(1): 77-83, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11995638

RESUMO

The morphological effects of ethanol ingestion on the hard palatine mucosa of adult male Calomys callosus were observed. Twenty rodents were divided into two experimental groups: the control group received solid diet, Purina rat chow, and tap water ad libitum; the alcoholic group received the same solid diet and ethanol P.A. diluted 20% in water (v/v). After 270 days of treatment, all animals were sacrificed and the hard palatine mucosa were prepared for TEM and SEM methods. The epithelial cells of the alcoholic group showed some alterations like cytoplasmatic lipid droplets, pycnotic nucleus and increased mitochondrial size. The lamina propria also presented intense lipid droplets accumulation. The morphological changes suggested that chronic ethanol consumption was able to modify the integrity of the mucosa.


Assuntos
Alcoolismo/patologia , Mucosa Bucal/ultraestrutura , Palato Duro/ultraestrutura , Animais , Masculino , Camundongos
16.
J Dent ; 29(6): 435-41, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11520593

RESUMO

OBJECTIVE: The purpose of this study was to measure the tensile bond strength (TBS) testing of resin composite to dentin of three low-viscosity composites, in association with an unfilled adhesive, and a filled adhesive one and two coats respectively, and to evaluate and compare the SEM morphological observations. METHODS: The labial surface of 120 bovine lower incisors were ground to obtain a flat dentin surface allowing demarcation of a 4 mm diameter area with adhesive tape. The teeth were randomly divided in six groups of 20 each. The dentin of each ground surface was etched with 35% H(3)PO(4) for 15s, followed by application of the respective adhesive: Single Bond (SB) for Groups 1, 2, 3 and 6; Optibond Solo (OS) for Groups 4 and 5. In Groups 1 and 4, a resin composite rod with a wire loop was luted directly to the adhesive surface with Z100. Group 2 received an intermediate layer of Flow It (FI) composite; Group 3 received an intermediate layer of Protect Liner F (PLF) composite; Group 5 received a second coat of OS; and Group 6 received an intermediate layer of an experimental low-viscosity composite (EM). A resin composite rod was luted to the surface of each specimen with Z100 resin composite. All specimens were stored in distilled water at 37 degrees C for 24h prior to TBS testing. Each specimen was inspected by SEM and classified according to adhesive or cohesive failure mode. One specimen of each group was cut longitudinally, polished and prepared for SEM observation. RESULTS: The TBS values were: Group 1 (7.86MPa+/-2.28), Group 2 (7.62MPa+/-1.85), Group 3 (7.60MPa+/-2.14), Group 4 (7.96MPa+/-2.36), Group 5 (7.50MPa+/-2.70) and Group 6 (7.18MPa+/-2.40). No significant statistical differences were observed among the groups. However, the analyses of the failure mode presented a considerable variation. SIGNIFICANCE: The use of a filled adhesive or an unfilled adhesive along with a low-viscosity composite as an intermediate layer may provide a stress absorbing layer, whereby improving the preservation of the bonded interface area.


Assuntos
Resinas Compostas , Colagem Dentária/métodos , Falha de Restauração Dentária , Adesivos Dentinários , Cimentos de Resina , Adesivos , Análise de Variância , Animais , Bis-Fenol A-Glicidil Metacrilato , Bovinos , Adaptação Marginal Dentária , Permeabilidade da Dentina , Elasticidade , Teste de Materiais , Metacrilatos , Microscopia Eletrônica de Varredura , Dióxido de Silício , Propriedades de Superfície , Resistência à Tração , Viscosidade , Zircônio
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