Lack of chemoprevention of dietary Agaricus blazei against rat colonic aberrant crypt foci

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Injectable gels of anionic collagen : rhamsan composites for plastic correction: Preparation, characterization, and rheological properties

The present article describes the preparation and characterization A anionic Collagen gels obtained from porcine intestinal submucosa after 72 h of alkaline treatment and in the form of rhamsan composites to develop injectable biomaterials for plastic for construction. All materials were characterized by SDS/polyacrylamide gel electrophoresis, infrared spectroscopy, thermal stability, potentiometric titration, rheological properties, and fluidity tests. Biocompatibility was appraised after the injection of anionic collagen:rhamsan composites at 2.5% in 60 North Folk rabbits. Independently of processing, the Collagen's secondary structure was preserved in all cases, and after 72 h of hydrolysis the Collagen was characterized by a carboxyl group content of 346 :L 9, which, at physiological pH, corresponds to an increase of 106 17 negative charges, in comparison to native Collagen, due to the selective hydrolysis of asparagine and glutamine carboxyamide side chain. Rheological studies of composites at pH 7.4 in concentrations of 2, 4, and 6% (in proportions of 75:1 and 50:1) showed a viscoelastic behavior dependent on the frequency, which is independent of concentration and proportion. In both, the concentration of the storage modulus always predominated over the loss modulus (G' > G and delta < 45 degrees). The results from creep experiments confirmed this behavior and showed that anionic collagen:rhamsan composites at pH 7.4 in the proportion of 50:1 are less elastic and more susceptible to deformation in comparison to gels in the proportion of 75:1, independent of concentration. This was further confirmed by flow experiments, indicating that the necessary force for the extrusion of anionic collagen:rhamsan composites, in comparison to anionic Collagen, was significantly smaller and with a smooth flow. Biocompatibility studies showed that the tissue reaction of anionic collagen:rhamsan composites at 2.5% in the proportion of 75:1 was compatible with the application of these gels in plastic reconstruction. These results suggest that the association of Collagen with rhamsan may be a good alternative in the replacement of glutaraidehyde to stabilize the microfibril assembly of commercial Collagen gel preparations. (c) 2005 Wiley Periodicals, Inc.

Digital dermatitis of the accessory digits of dairy cows

Esse estudo caracteriza lesões de dermatite digital (DD) nos dígitos acessórios de vacas leiteiras, além de apresentar a terapia aplicada. Foram utilizados 15 bovinos leiteiros da raça Holandês com DD nos dígitos acessórios dos membros pélvicos. Os animais eram provenientes de quatro fazendas leiteiras com histórico prévio de dermatite digital (DD). Todos os quinze animais foram tratados da mesma forma: após excisão das lesões e sutura das feridas cutâneas, aplicou-se oxitetraciclina pó topicamente sob bandagem e oxitetraciclina (20mg/kg) de longa ação, via intramuscular. Obtiveram-se amostras de tecidos para histopatologia, inclusive por microscopia eletrônica de transmissão (MET). Observou-se cicatrização em todos os animais após 15 dias do procedimento cirúrgico. A maioria das lesões macroscópicas foram projeções papilomatosas ou em forma de verrugas. Os achados histopatológicos de todas as amostras revelaram hiperplasia da epiderme com hiperceratose, inúmeras mitoses no estrato basal, com invasões alongadas em forma de rede na derme superficial e intermediária. A MET evidenciou organismos com formas longas, afiladas e espiraladas, presumivelmente espiroquetas. Tanto as características morfológicas, quanto a resposta à terapia das lesões foram comparáveis às descritas para DD.

Ethnoveterinary knowledge and practices at Colares island, Para state, eastern Amazon, Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Inhibition of Mouse Urinary Bladder Carcinogenesis by A double dagger ai Fruit (Euterpe oleraceae Martius) Intake

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The effects of Brazilian and Bulgarian propolis in vitro against Salmonella Typhi and their synergism with antibiotics acting on the ribosome

Salmonella enterica serovar Typhi is the causative agent of typhoid fever in humans, and the use of antibiotics is essential for controlling this infection; however, the excessive use of antibiotics may select resistant strains. Propolis is a honeybee product and its antimicrobial activity has been intensively investigated. Thus, the objective of this study was to investigate a possible synergism between propolis (collected in Brazil and Bulgaria) and antibiotics acting on the ribosome (chloramphenicol, tetracycline and neomycin) against Salmonella Typhi in vitro. The synergism was investigated by using 1/2 and 1/4 of the minimum inhibitory concentration for propolis and these antimicrobial agents, evaluating the number of viable cells according to the incubation time. Brazilian propolis showed a bacteriostatic action against S. Typhi, while Bulgarian propolis showed a bactericidal activity and a synergistic effect with the three antibiotics. Variations in the biological assays might be due to the differences in their chemical compositions. Based on the results, one may conclude that Bulgarian propolis showed an important antibacterial action, as well as a synergistic effect with antibiotics acting on the ribosome, which points out a possible therapeutic strategy evaluating the use of propolis preparations for the treatment of Salmonella Typhi infection.

Comparative evaluation of an indirect ELISA test for diagnosis of swine cysticercosis employing antigen from Taenia solium and Taenia crassiceps metacestodes

Taenia solium cysticercosis is still a serious public health problem in several countries where poverty and lack of hygiene favor transmission. Because pigs are the primary intermediate hosts, prevalence of porcine cysticercosis is a reliable indicator of active transmission zones. Serological diagnostic methods are important tools for epidemiological studies since they can be applied to living animals on a large scale. Four antigen preparations (cyst fluid and crude) from T. solium and T. crassiceps metacestodes were compared for swine cysticercosis diagnosis by indirect ELISA (IE). Twenty-eight serum samples from swine naturally and experimentally infected by cysticerci of T. solium and 56 serum samples from swine reared in commercial herds were tested. Best results of overall sensitivity were obtained by the use of cyst fluid and crude antigen of T. crassiceps metacestode (100 and 96.4%, respectively). Using homologous antigen preparations we have observed higher specificity percentage (98.2% for cyst fluid and 96.4% for crude metacestode T. solium antigen). We concluded that sensitivity is of far more importance than specificity for identification of endemic areas in order to prevent transmission to man. We conclude, therefore, that IE performed with cyst fluid antigen of T. crassiceps metacestode is a better tool for that purpose. (C) 2000 Elsevier B.V. B.V. All rights reserved.

Uso da flunixina meglumina tópica no tratamento de uveítes em cães

Este trabalho teve por objetivo comparar o efeito (uso tópico) da flunixina meglumina e da dexametasona no controle da uveíte anterior em cães, por meio de avaliação clínica e pela dosagem de proteínas no humor aquoso. Foram utilizados 17 cães portadores de uveíte anterior de diversas etiologias. Os animais, divididos em dois grupos, foram tratados durante 15 dias. Observou-se maior eficácia da flunixina meglumina na cura clínica das uveítes e na redução significativa da concentração de proteínas no humor aquoso em relação à dexametasona. Concluiu-se que a preparação comercial de uso parenteral pode ser utilizada como colírio no tratamento de doenças inflamatórias da úvea.

Periodontal tissue response to coverage of root cavities restored with resin materials: A histomorphometric study in dogs

Background: the purpose of this study was to histomorphometrically evaluate the response of periodontal tissues covering Class V resin restorations in dogs.Methods: After raising a mucoperiosteal flap, bony defects measuring 5 x 5 mm were created on the buccal aspect of the canines of five dogs followed by cavity preparations on the root surface measuring 3 x 3 x 1 mm. Before repositioning the flap to cover the bone defect, the cavities were restored with composite resin (CR) or resin-modified glass ionomer cement (RMGIC) or were left unrestored as control (C). The dogs were euthanized 90 days after surgery. Specimens comprising the tooth and periodontal tissues were removed, processed routinely, cut into longitudinal serial sections in the bucco-lingual direction, and stained with hematoxylin and eosin (H&E) or Masson's trichrome. The most central sections were selected for histomorphometric analysis.Results: Histomorphometric analysis revealed apical migration of epithelial tissue onto the restorative materials (RMGIC and CR). The C group presented significantly longer connective tissue attachment (P < 0.05) than the RMGIC and CR groups and significantly higher bone regeneration (P < 0.05) compared to the RMGIC group. Histologically, the cervical third (CT) of all groups had the most marked chronic inflammatory infiltrate.Conclusions: Within the limits of this study, it can be concluded that the restorative materials used exhibit biocompatibility; however, both materials interfered with the development of new bone and the connective tissue attachment process.

Clinical assessment of postoperative sensitivity in posterior composite restorations

This incidence of postoperative sensitivity was evaluated in resin-based posterior restorations. Two hundred and ninety-two direct restorations were evaluated in premolars and molars. A total of 143 Class I and 149 Class 11 restorations (MO/OD and MOD) were placed in patients ranging in age from 30 to 50 years. After the cavity preparations were completed, a rubber dam was placed, and the preparations were restored using a total-etch system (Prime & Bond NT) and a resin-based restorative material (TPH Spectrum). The patients were contacted after 24 hours and 7, 30 and 90 days postoperatively and questioned regarding the presence of sensitivity and the stimuli that triggered that sensitivity. The Chi-square and Fisher's Exact Test were used for statistical analysis. Evaluation at 24 hours after restorative treatment revealed statistically significant differences among the types of cavity preparations restored and the occurrence of postoperative sensitivity (p=0.0003), with a higher frequency of sensitivity in Class H MOD restorations (26%), followed by Class II MO/DO (15%) and Class I restorations (5%). At 7, 30 and 90 days after restorative treatment, there was a decrease in the occurrence of sensitivity for all groups. The percentage of sensitivity among the groups was not significantly different. This study shows that the occurrence of sensitivity is correlated with the complexity of the restoration.

Micromorphologic assessment of CVD (chemical vapor deposition) and conventional diamond tips and their cutting effectiveness

The aim of this study was to compare the micromorphology of CVD diamond tips coupled to ultrasound with conventional high speed diamond tips after cavity preparations, and to measure the width and depth of the cavities obtained. Two hundred bovine teeth were divided into 20 subgroups. Each of the diamond tips (10 CVD and 10 conventional) were used to prepare 10 standardized cavities, using an apparatus that controlled the time (t: 27 s), speed (5.3 mm/s) and load (0.012 KGF) of the tip against the teeth during preparation. The unused and the used (after one, five and 10 preparations) tips were analyzed by scanning electronic microscopy. The images were randomly assessed by 3 examiners with regard to the presence or absence of micromorphologic alterations. Cavity measurements were made after visualization under a stereoscopic microscope. Cavity widths and depths were analyzed by the ANOVA Factorial test (p < 0.05). The CVD diamond tips presented less wear than the conventional tips after all the cavity preparations performed, but produced shallower cavities that were equivalent in width to those made by conventional tips after the fifth preparation. CVD diamond tips may be suggested as an alternative to conventional diamond tips due to their conservative preparation and greater longevity.

Response of human pulps following acid conditioning and application of a bonding agent in deep cavities

Objectives. The aim of this in vivo study was to evaluate the human dental pulp response when a one-bottle adhesive system was applied on etched or unetched deep dentine.Methods. Eighteen class V deep cavity preparations were divided in three groups: group 1-total etching + two coats of single bond (SB) + composite resin (Z-100); group 2-enamel etching + two coats of SB + Z-100, group 3-cavity floor lined with a calcium hydroxide liner (Dycal) + acid-etching of enamel and lateral walls + two coats of SB + Z-100. Two teeth were used as intact control group. After 30 days the teeth were extracted and processed through H and E, Masson's trichrome and Brown and Brenn staining techniques.Results. Moderate inflammatory response, disorganization of pulp tissue, as well as, deposition of thin layer of reactionary dentin were observed in group 1 teeth in which the remaining dentin thickness (RDT) was less than 300 mum. These histological findings appear to be related to long resin tags formation and bonding agent diffusion through dentinal tubules. In group 2, slight inflammatory response was observed only in one tooth in which the RDT was 162 mum. In group 3, all the teeth showed normal histological characteristics which were similar to the intact control group. Presence of bacteria was not correlated with the intensity of pulpal response. The patients reported no symptoms during the experiment. Radiographic evaluation showed no periapical pathology for any of the teeth,Significance and conclusions. Acid-etched deep dentin (RDT less than 300 mum) lined with SB causes more intense pulpal response than unetched deep dentin. Based on the results observed in the present study and the conditions in which it was carried out, we recommend the application of a biocompatible liner before etching deep dentin and applying SB. (C) 2002 Academy of Dental Materials. Published by Elsevier B.V. Ltd. All rights reserved.

Switching control of sympathetic activity from forebrain to hindbrain in chronic dehydration

We investigated the mechanisms responsible for increased blood pressure and sympathetic nerve activity (SNA) caused by 2-3 days dehydration (DH) both in vivo and in situ preparations. In euhydrated (EH) rats, systemic application of the AT(1) receptor antagonist Losartan and subsequent pre-collicular transection (to remove the hypothalamus) significantly reduced thoracic (t) SNA. In contrast, in DH rats, Losartan, followed by pre-collicular and pontine transections, failed to reduce tSNA, whereas transection at the medulla-spinal cord junction massively reduced tSNA. In DH but not EH rats, selective inhibition of the commissural nucleus tractus solitarii (cNTS) significantly reduced tSNA. Comparable data were obtained in both in situ and in vivo (anaesthetized/conscious) rats and suggest that following chronic dehydration, the control of tSNA transfers from supra-brainstem structures (e. g. hypothalamus) to the medulla oblongata, particularly the cNTS. As microarray analysis revealed up-regulation of AP1 transcription factor JunD in the dehydrated cNTS, we tested the hypothesis that AP1 transcription factor activity is responsible for dehydration-induced functional plasticity. When AP1 activity was blocked in the cNTS using a viral vector expressing a dominant negative FosB, cNTS inactivation was ineffective. However, tSNA was decreased after pre-collicular transection, a response similar to that seen in EHrats. Thus, the dehydration-induced switch in control of tSNA from hypothalamus to cNTS seems to be mediated via activation of AP1 transcription factors in the cNTS. If AP1 activity is blocked in the cNTS during dehydration, sympathetic activity control reverts back to forebrain regions. This unique reciprocating neural structure-switching plasticity between brain centres emphasizes the multiple mechanisms available for the adaptive response to dehydration.

Evaluation of Ultrasonic and ErCr:YSGG Laser Retrograde Cavity Preparation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

THE EFFECT of IMMEDIATE DENTIN SEALING on THE MARGINAL ADAPTATION and BOND STRENGTHS of TOTAL-ETCH and SELF-ETCH ADHESIVES

Statement of problem. Sealing ability and bond strengths of total-etch and self-etch dentin adhesives used for immediate dentin sealing have not been assessed and established.Purpose. The purpose of this study was to determine the effectiveness of immediate dentin sealing (IDS) using total-etch or self-etch dentin adhesives on microleakage and microtensile bond strength.Material and methods. Twenty recently extracted molars were selected, and standard MOD inlay preparations were made with the gingival margins located below the cemento-enamel unction. The teeth were assigned to 4 experimental groups (n=5) according to the indirect composite restoration cementation technique used: (1) immediate dentin sealing with Adper Single Bond (TEBI); (2) conventional adhesive cementation technique using Adper Single Bond (TEAI); (3) immediate dentin sealing using Adper Prompt L-Pop (SEBI); or (4) conventional adhesive cementation technique using Adper Prompt L-Pop (SEAI). The restored teeth were thermal cycled 1,000 times between 5 degrees and 55 degrees C and then immersed in 50% ammoniacal silver nitrate. Three specimens per restoration were evaluated for microleakage, according to predefined scores, and submitted to Friedman's test (alpha-.05). The specimens were then sectioned to obtain 0.8 +/- 0.2-mm-thick sticks (with n ranging from 32 to 57 specimens) and submitted to microtensile bond strength (mu TBS) testing. The obtained data were submitted to 2-way ANOVA test (alpha=.05).Results. None of the experimental groups demonstrated complete elimination of marginal microleakage. There were significant differences in microleakage of the tested adhesives (P>.001). IDS microleakage scores were similar to those obtained using the conventional cementation technique (CCT) for both adhesives. The highest mean bond strengths were obtained with TEBI (51.1 MPa), whereas SEAI showed the lowest mean bond strengths (1.7 MPa). IDS resulted in significantly higher bond strengths than CCT (P<.001).Conclusions. Total-etch and self-etch adhesives have a significant effect on IDS. IDS resulted in high bond strengths for both adhesives; however, the microleakage was similar to that obtained with CCT (J Prosthet Dent 2009;102:1-9)