920 resultados para Tissue Culture Techniques
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Electrospun polyaniline nanofibers are one of the most promising materials for cardiac tissue engineering due to their tunable electroactive properties. Moreover, the biocompatibility of polyaniline nanofibes can be improved by grafting of adhesive peptides during the synthesis. In this paper, we describe the biocompatible properties and cardiomyocytes proliferation on polyaniline electrospun nanofibers modified by hyperbranched poly-L-lysine dendrimers (HPLys). The microstructure characterization of the HPLys/polyaniline nanofibers was carried out by scanning electron microscopy (SEM). It was observed that the application of electrical current stimulates the differentiation of cardiac cells cultured on the nanofiber scaffolds. Both electroactivity and biocompatibility of the HPLys based nanofibers suggest the use this material for culture of cardiac cells and opens the possibility of using this material as a biocompatible electroactive 3-D matrix in cardiac tissue engineering.
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In vitro morphogenesis and cell suspension culture establishment in Piper solmsianum C. DC. (Piperaceae)). Piper solmsianum is a shrub from Southeast Brazil in which many biologically active compounds were identified. The aim of this work was to establish a cell suspension culture system for this species. With this in mind, petiole and leaf explants obtained from in vitro plantlets were cultured in the presence of different plant growth regulator combinations (IAA, NAA, 2,4-D and BA). Root and indirect shoot adventitious formation, detected by histological analysis, was observed. Besides the different combinations of plant growth regulators, light regime and the supplement of activated charcoal (1.5 mg.l(-1)) were tested for callus induction and growth. Cultures maintained in light, on a 0.2 mg.l(-1) 2,4-D and 2 mg.l(-1) BA supplemented medium, and in the absence of activated charcoal, showed the highest calli fresh matter increment. From a callus culture, cell suspension cultures were established and their growth and metabolite accumulation studied. The achieved results may be useful for further characterization of the activated secondary metabolites pathways in in vitro systems of P. solmsianum.
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Fan culture is a subculture that has developed explosively on the internet over the last decades. Fans are creating their own films, translations, fiction, fan art, blogs, role play and also various forms that are all based on familiar popular culture creations like TV-series, bestsellers, anime, manga stories and games. In our project, we analyze two of these subculture genres, fan fiction and scanlation. Amateurs, and sometimes professional writers, create new stories by adapting and developing existing storylines and characters from the original. In this way, a "network" of texts occurs, and writers step into an intertextual dialogue with established writers such as JK Rowling (Harry Potter) and Stephanie Meyer (Twilight). Literary reception and creation then merge into a rich reciprocal creative activity which includes comments and feedback from the participators in the community. The critical attitude of the fans regarding quality and the frustration at waiting for the official translation of manga books led to the development of scanlation, which is an amateur translation of manga distributed on the internet. Today, young internet users get involved in conceptual discussions of intertextuality and narrative structures through fan activity. In the case of scanlation, the scanlators practice the skills and techniques of translating in an informal environment. This phenomenon of participatory culture has been observed by scholars and it is concluded that they contribute to the development of a student’s literacy and foreign language skills. Furthermore, there is no doubt that the fandom related to Japanese cultural products such as manga, anime and videogames is one of the strong motives for foreign students to start learning Japanese. This is something to take into pedagogical consideration when we develop web-based courses. Fan fiction and fan culture make it possible to have an intensive transcultural dialogue between participators throughout the world and is of great interest when studying the interaction between formal and informal learning that puts the student in focus
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Aim. This study aimed at assessing the accuracy of ultrasound (US) in the diagnosis of recent deep vein thrombosis (DVT) in an experimental study in dogs.Methods. Design: blinded and randomized experimental study. Twenty dogs were randomly divided in two groups: control group (CG) and thrombosis group (TG). US was performed in the pre- and postoperative period. Phlebography was performed immediately prior to the postoperative US. After the second US, a surgery was performed to detect whether thrombus was present or not. US results were compared to those of phlebography and surgical findings.Results. in all dogs, inferior vena cava (IVC) was compressible. The relations of IVC diameter with the aorta were higher (P<0.005) in TG than in CG. Spectral Doppler in spontaneous breathing, tissue harmonic imaging, power Doppler and B flow showed sensitivity, specificity and accuracy of 1. Phlebography presented sensitivity of 90%, specificity of 80% and accuracy of 85%, when compared to surgical finding.Conclusion. For the diagnosis of recent DVT in the experimental model used, venous compressibility proved to be inefficient. The ratio of WC diameter to aorta, when increased, suggests thrombosis. The use of new US technological advances increases accuracy. Phlebography was less accurate than US.
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In order to contribute to a better understanding of cytokine participation in borderline leprosy, in the present study we determined - by in vitro and in situ examinations - the production of these cytokine mediation in non-treated borderline tuberculoid (BT) patients and borderline lepromatous (BL) patients. Seven non-treated BT patients, 12 non-treated BL patients, besides 19 healthy individuals (control group), were evaluated. Peripheral blood mononuclear cells (PBMC) were stimulated or not with specific-M. leprae stimulus (whole and sonicated M. leprae antigens) and a non-specific stimulus. After 48 hours, supernatant was collected for TNF-alpha, IFN-gamma, IL-10 and TGF-beta1 cytokine determination by ELISA. Biopsies from cutaneous lesions were submitted to histological analysis and hematoxylin-eosin and Fite-Faraco stainings; the sections then underwent iNOS, IL-10 and TGF-beta1 in situ detection by immunohistochemistry. Cytokine quantification in PBMC supernatants from patients showed that BT patients produced higher levels of IFN-gamma. Compared to healthy individuals, both borderline patient groups produced lower levels of TGF-beta1 while BL patients generated lower IL-10 levels. The in situ iNOS expression was higher in BT patients compared to BL individuals. on the order hand, TGF-beta1 cytokine revealed a higher proportion of immunostained cells in BL patients. There was no significant difference in IL-10 level between BT and BL patients. Regarding cutaneous lesions, in BL patients there was a negative correlation between TGF-beta1 tissue expression and IL-10. Independently of the clinical form, we observed a positive correlation between TGF-beta1 and bacterial index as well as a negative correlation between the TGF-beta1 tissue expression and iNOS. The results even showed a positive correlation between iNOS tissue expression and production of IFN-gamma by PBMC stimulated with M. leprae antigens. Taken together, the histopathological and immunological observations reinforce the notion of immunological instability in borderline leprosy patients and indicating the participation of mixed cytokines profiles in these individuals, specifically a Th1 profile in BT patients and Th2 profile in BL patients, with a possible participation of T-regulatory lymphocytes.
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The tissue microarray (TMA) technique allows multiple tissue samples in a single block. Commercial adhesive tape is used to avoid the loss of tissue samples during the immunostaining process. Few reports exist in the literature comparing the use of these adhesive tapes to other adhesive techniques. The objective of this study was to compare loss of sections adhered to slides using commercial adhesive tapes versus using silanized only slides. TMA was constructed with varying tissues using a fixed-base device (Beecher Instruments), placing 108 cylinders of 1 mm diameter in duplicate, spaced 1.2 mm apart. Section of 4 mu m were cut from the TMA block and adhered to 30 silanized slides and 30 commercial glass slides using adhesive tape, according to manufacturer's recommendations. Vimentin immunoexpression was evaluated by immunohistochemistry. Antigenic recovery was realized in citrate buffer using a microwave oven. Cylinder loss in the immunohistochemical process was quantified and expressed as: total (>80%), almost complete (75-79%), or partial (50-74%). The commercial adhesive tape group presented lesser total loss (1.1 versus 6.4%), almost complete loss (2.2 versus 3.5%), and partial loss (2.1 versus 3.8%) than the silanized slide group (ANOVA, P < 0.05). The sum of total and almost complete losses in the silanized slide group was 9.9%, greater than the losses in slides using commercial adhesive tapes (3.3%) and less than reported and considered acceptable in the literature (10-30%). In conclusion, the use of silanized only slides presents very satisfactory results, requires less training, and reduces costs significantly, thus justifying their use in research.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The aim of this study was to evaluate the application of PCR technique for the detection of BoHV-5 in routinely formalin-fixed, paraffin-embedded brain tissues in 20 naturally infected calves affected by fatal meningoencephalitis. Brains were divided into two halves, one kept fresh for virus isolation and PCR assay, targeting the glycoprotein C gene from BoHV-5 genome. The other half brain, corresponding to posterior cortex region, was submitted to formalin fixation and embedded into paraffin blocks for microscopic evaluation and total DNA isolation. Most of the slides showed severe multifocal non-supurative encephalitis with neuronal degeneration, neurophagia, and no acidophilic intranuclear inclusions could be found in neurons and glial. The 20 fresh samples were confirmed, by virus isolation and PCR assay, as having the BoHV-5 virus and, respective glicoprotein C sequence, while 15 of 20 formalin-fixed, paraffin-embedded samples were considered positive for the same analysis. The results revealed the first description of PCR efficiency, applied to formalin-fixed, paraffin-embedded brain collected from naturally infected calves, improving the detection of BoHV-5 from archival samples in South America. (c) 2007 Published by Elsevier B.V.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The purpose of this study was to investigate the influence of the type of vehicle (distilled water or propyleneglycol) on the response of apical tissues of dogs' teeth after root canal filling with mineral trioxide aggregate (MTA) at two different limits. Forty roots of incisors and premolars of two adult dogs were used. After pulpectomy, the root canals were prepared biomechanically, and the roots had the apical cemental barrier penetrated with a #15 K-file and widened to a #25 K-file. The root canals were assigned to four groups according to the vehicle used for MTA (ProRoot-MTA; Tulsa Dental, Tulsa, OK) preparation and the limit of root canal filling: group 1, filling with MTA/distilled water to the limit of the cemental canal; group 2, overfilling with MTA/distilled water, group 3, filling with MTA/propyleneglycol to the limit of the cemental canal; and group 4, overfilling with MTAlpropyleneglycol. The animals were killed by anesthetic overdose 90 days after endodontic treatment and the anatomic pieces were prepared for histomorphological analysis. The sections were stained with hematoxylin and eosin and Brown and Brenn techniques. The results showed that MTA pastes prepared with either distilled water or propyleneglycol as vehicles had similar biological behavior (p > 0.05); root fillings placed at the cemental canal limit showed better results than the overfillings (p = 0.01), and MTA/propyleneglycol paste was more easily placed into the root canals than MTA/distilled water paste.
Tissue reaction to Endométhasone sealer in root canal fillings short of or beyond the apical foramen
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Objective: This study evaluated the response of periapical tissues to the endodontic sealer Endomethasone in root canal fillings short of or beyond the apical foramen. Material and Methods: Twenty root canals of premolars and incisors of 2 mongrel dogs were used. After coronal access and pulp extirpation, the canals were instrumented up to a size 55 K-file and the apical cemental barrier was penetrated with a size 15 K-file to obtain a main apical foramen, which was widened to a size 25 K-file. The canals were irrigated with saline at each change of file. The root canals were obturated either short of or beyond the apical foramen by the lateral condensation of gutta-percha and Endomethasone, originating 2 experimental groups: G1: Endomethasone/short of the apical foramen; G2: Endomethasone/beyond the apical foramen. The animals were killed by anesthetic overdose 90 days after endodontic treatment. The individual roots were obtained and serial histological sections were prepared for histomorphological analysis (H&E and Brown & Brenn techniques) under light microscopy. The following parameters were examined: closure of the apical foramen of the main root canal and apical opening of accessory canals, apical cementum resorption, intensity of the inflammatory infiltrate, presence of giant cells and thickness and organization of the apical periodontal ligament. Each parameter was scored 1 to 4, 1 being the best result and 4 the worst. Data were analyzed statistically by the Wilcoxon nonparametric tests (p=0.05). Results: Comparing the 2 groups, the best result (p<0.05) was obtained with root canal filling with Endomethasone short of the apical foramen but a chronic inflammatory infiltrate was present in all specimens. Conclusions: Limiting the filling material to the root canal space apically is important to determine the best treatment outcome when Endomethasone is used as sealer.