76 resultados para Coloração

em Universidade Federal do Rio Grande do Norte(UFRN)


Relevância:

10.00% 10.00%

Publicador:

Resumo:

RESUMO: Objetivo: Tem sido demonstrado que a icterícia obstrutiva provoca depressão do sistema imunológico, mudança no padrão de colonização bacteriana dos intestinos e passagem de bactérias da luz intestinal para a circulação porta e sistêmica. Estudo experimental em ratos procurou observar a possibilidade de translocação bacteriana para os pulmões após a ligadura do colédoco. Método: Foram utilizados 20 ratos Wistar pesando de 178 a 215g, separados aleatoriamente em dois grupos iguais. Nos ratos do grupo I foi feita a ligadura do colédoco e nos do grupo II apenas a manipulação do colédoco com pinça atraumática (sham operation). No sétimo dia de observação os animais foram mortos com superdose de anestésico, sangue foi colhido para dosagem de bilirrubinas e os pulmões ressecados sob condições assépticas. Metade de cada pulmão foi homogeneizada e semeada em meios de cultura ágar McConkey e ágar sangue. A outra metade serviu para exame histopatológico –coloração hematoxilina e eosina. Os dados foram analisados pelo teste t, com significância 0,05. Resultados: revelaram bilirrubina total em média 18,7±3,6 no grupo I e 0,7±0,2 no grupo II. No grupo I foram isoladas colônias de Klebsiela sp nos pulmões de 30% dos animais e E. coli em 20%, e os escores histopatológicos atingiram a média 6,2±2,08. No grupo II não foram detectadas bactérias nos pulmões e os escores do exame histopatológico atingiram 1,8±1,16. A diferença dos dados analisados mostrou-se significativa (p<0,05). Conclusões: Concluiu-se que a icterícia obstrutiva por ligadura do colédoco em ratos provocou translocação de germes Gram-negativos para os pulmões e resultou em alterações histopatológicas significativas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Perciformes are dominant in the marine environment, characterized as the largest and most diverse fish group. Some families, as Gerreidae, popularly known as silver jennies, carapebas, or mojarras have a high economic potential to marine fish farming, natural explotation and game fishing. Genetic information of these species are of fundamental importance for their management and production. Despite exist over 13,000 marine fish species described, only 2% were cytogenetically analyzed and less than 1% have some reproductive characteristics known. Induced breeding, cytogenetic characterization and cryopreservation of gametes, represent important areas in applied fish studies. In this project cytogenetic analyzes were performed to acess genetic aspects of Gerreidae species, distributed in coastal and estuarine regions of Northeast Brazil. Different methods for identifying chromosomal regions were employed using conventional techniques (Ag-NORs, C-banding), staining with base-specific fluorochromes (DAPI-CMA3), and physical mapping of ribosomal genes 18S and 5S rDNA, through hybridization in situ with fluorescent probes (FISH). The six species analyzed showed remarkable chromosome conservatism. The 18S and 5S ribosomal genes when analyzed in phylogenetic perspective demonstrate varied evolutionary dynamics, suggesting ocurrence of stasis process in some groups and greater dynamism in others. Double FISH with 18S and 5S probes showed both how efficient cytotaxonomic markers in the homogeneous karyotypes of this group of species. The karyotypic pattern identified in addition to the evolutionary aspects of karyotype, are suggestive of existence of low potential of post-zygotic barrier, prompting further research to prospect for artificial interspecific hybridization of these species of commercial importance

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Inorganic pigment comprises a host lattice, which is part of the chromophore component (usually a transition metal cation) and possible components modifiers, which stabilize, add or restate the properties pigments. Among the materials with spinel, ferrites, and the chromite stand out, because they have broad technological importance in the area of materials, applicability, pigments, catalytic hydrogenation, thin film, ceramic tiles, among others. The present work, pigments containing CuFe2O4, CuCr2O4,e CuFeCrO4, were synthesized by a method that makes use of gelatin as organic precursor using their application to ceramic pigments. The pigments were characterized by X-ray diffraction (XRD), Infrared spectroscopy, scanning electron microscopy (SEM) spectroscopy in the UV-visible and Colorimetry. The results confirmed the feasibility of the synthetic route used, with respect to powders synthesized, there is the formation of spinel phase from 500°C, with an increase in crystallinity and the formation of other phases. The pigments were shown to be crystalline and the desired phases were obtained. The copper chromite have hues ranging from green to black according to the calcination temperature, while the copper chromite doped with iron had brownish. The ferrites showed copper color and darker brown to black, which may indicate an interesting factor because of the importance of black pigment

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Currently new polymeric materials have been developed to replace other of traditionally materials classes. The use of dyes allows to expand and to diversify the applications in the polymeric materials development. In this work the behavior and ability of azo dyes Disperse Blue 79 (DB79) and Disperse Red 73 (DR73) on poly(methyl methacrylate) (PMMA) were studied. Two types of mixtures were used in the production of masterbatches: 1) rheometer 2) solution. Processing by extrusion-blow molding of PMMA was carried out in order to evaluate the applications of polymeric films. Thermal analysis were performed by thermogravimetry to evaluate polymer and azo dyes thermal stability. Colorimetric analysis were obtained through monitoring the spectral variations associated with sys/trans/anti azo dyes isomerization process Colorimetric data were treated and evaluated in accordance to the color system RGB and CIEL*ab, by monitoring the color change as function of time. Mechanical properties, characterized by tensile tests, were evaluated and correlated with the presence and content of azo dyes in the samples. Analyses by scanning electronic microscopy (SEM) were performed on the surfaces of samples to check the azo dye dispersion after the mixing process. It was concluded that the production of PMMA/azo dyes is possible and feasible, and the mixtures produced had synergy of properties for use in various applications

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In a hospital environment, these bacteria can be spread by insects such as ants, which are characterized by high adaptability to the urban environment. Staphylococcus is a leading cause of hospital infection. In Europe, Latin America, USA and Canada, the group of coagulase negative staphylococci (CoNS) is the second leading cause of these infections, according to SENTRY (antimicrobial surveillance program- EUA). In this study, we investigated the potential of ants (Hymenoptera: Formicidae) as vehicle mechanics of Staphylococcus bacteria in a public hospital, in Natal-RN. The ants were collected, day and night, from June 2007 to may 2008, in the following sectors: hospitals, laundry, kitchen, blood bank. The ants were identified according to the identification key of Bolton, 1997. For the analysis of staphylococci, the ants were incubated in broth Tryptic Soy Broth (TSB) for 24 hours at 35 º C and then incubated on Mannitol Salt Agar. The typical colonies of staphylococci incubated for 24 hours at 35 ° C in Tryptic Soy Agar for the characterization tests (Gram stain, catalase, susceptibility to bacitracin and free coagulase). The identification of CoNS was performed through biochemical tests: susceptibility to novobiocin, growth under anaerobic conditions, presence of urease, the ornithine decarboxylation and acid production from the sugars mannose, maltose, trehalose, mannitol and xylose. The antimicrobial susceptibility examined by disk-diffusion technique. The technique of Polymerase Chain Reaction was used to confirm the presence of mecA gene and the ability to produce biofilm was verified by testing in vitro using polystyrene inert surface, in samples of resistant staphylococci. Among 440 ants, 85 (19.1%) were carrying coagulase-negative staphylococci (CoNS) of the species Staphylococcus saprophyticus (17), Staphylococcus epidermidis (15), Staphylococcus xylosus (13), Staphylococcus hominis hominis (10), Staphylococcus lugdunensis (10), Staphylococcus warneri (6), Staphylococcus cohnii urealyticum (5), Staphylococcus haemolyticus (3), Staphylococcus simulans (3), Staphylococcus cohnii cohnii (2), and Staphylococcus capitis (1). No Staphylococcus aureus was found. Among the isolates, 30.58% showed resistance to erythromycin. Two samples of CoNS (2.35%), obtained from the ant Tapinoma melanocephalum collected in the post-surgical female ward, S. Hominis hominis and S. lugdunensis harbored the mecA gene and were resistant to multiple antibiotics, and the specie S. hominis hominis even showed to be a biofilm producer. This study proves that ants act as carriers of multidrug-resistant coagulase-negative Staphylococci and biofilm producers and points to the risk of the spreading of pathogenic microorganisms by this insect in the hospital environment

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Tamoxifen (TX), a drug used in the treatment of breast cancer, may cause hepatic changes in some patients. The consequences of its use on the liver tissues of rats with or without diabetes mellitus (DM) have not been fully explored. The purpose of this multidisciplinary study was to evaluate the correlation between plasma hepatic enzyme levels and the presence of iron overload in the hepatic tissue of female Wistar rats with or without streptozotocin-induced DM and using TX. Female rats were studied in control groups: C-0 (non-drug users), C-V (sorbitol vehicle only) and C-TX (using TX). DM (diabetic non-drug users) and DM-TX (diabetics using TX) were the test groups. Sixty days after induced DM, blood samples were collected for glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST) alkaline phosphatase (ALP) and bilirubin measures. Hepatic fragments were processed and stained with hematoxylin and eosin (H&E), Masson s trichrome, Perls. The hepatic iron content was quantified by atomic absorption spectrometry. AST, ALT and ALP levels were significantly elevated in the DM and DM-TX groups, with unchanged bilirubin levels. Liver iron overload using Perls stain and atomic absorption spectrometry were observed exclusively in groups C-TX and DM-TX. There was positive correlation between AST, ALT and ALP levels and microscopic hepatic siderosis intensity in group DM-TX. In conclusion, TX administration is associated with liver siderosis in diabetic and non-diabetic rats. In addition, TX induced liver iron overload with unaltered hepatic function in 2 non-diabetic rats and may be a useful tool for investigating the biological control of iron metabolism

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The decoction of Brazilian pepper tree barks (Schinus terebinthifolius, Raddi), is used in medicine as wound healing and antiinflamatory. Once extracts from this plant are used for acceleration of scar s process, it is important to study their mutagenic and genotoxic potential. In previous works in our laboratory, it was observed mutagenicity caused by the decoction when in high concentrations. Among the chemical compounds of this plant that could be able to induce mutation, the flavonoids were the only group that was referred to have either an oxidant or antioxidant potential. The flavonoids were isolated, purified and quantified by adsorptive column chromatography under silica gel, bacterial and in vitro genotoxic tests were realized to determine if the flavonoids were the responsible agents for this mutagenicity found. The tests realized with plasmidial DNA were indicative that the flavonoids are probably genotoxic, due to the presence of correlation between increase of the flavonoid concentration and in plasmidial DNA double strand breakage visualized in agarose gel, as well as they were capable to generated abasic sites shown by the in vitro treatment with exonuclease III. The same tests with plasmidial DNA in the presence of copper [10 µM] and of a Tris-HCl pH 7.5 [10 µM] buffer were realized with the isolated flavonoids to determine if there would be or not participation of reactive oxygen species (ROS). The transformation of plasmidial DNA in different bacterial strains proficient and deficient in DNA repair enzymes in the presence or not of a Tris-HCl buffer, suggests that the enzymes that repair oxidative lesions are necessary to repair the lesions generated by the flavonoids and that ROS are generated and are necessary to promote the lesions. Bacterial tests with Escherichia coli strains of the CC collection (deficient or not for DNA repair enzymes), showed that the flavonoids are able to increase the frequency of mutations, mainly in strains mutated in repair enzymes (MutM, MutY-glicosylases and double mutant), suggesting that these agents are responsible for the enhancement in the mutation rate. In order to determine the mutation spectrum caused by the flavonoids of the Brazilian pepper tree stem bark, plasmidial DNA previously treated with the flavonoids were transformed in bacterial strains deficient and proficient in the DNA repair enzymes, followed by a blue-white selection with X-gal, DNA amplification by PCR and sequencing the positive mutant clones. Analysis of the mutants obtained from strains CC104, CC104mutM, CC104mutY, CC104mutMmutY, BW9101, BW9109 indicated a predominance of some mutations like G:C to C:G that can be correlated with the origin of 8-oxoG, due to oxidative lesions caused by the flavonoids. So it can concluded that the flavonoid isolated or in fractions enriched on them are genotoxic and mutagenic, and their mutations are predominantly oxidative, mediated by ROS, and the lesions are recognized by the BER system. In this way it is proposed that the flavonoids can act in two different ways to generate the DNA lesion: 1. in a Fenton-like reaction, when the flavonoid are in the presence of metal ions and that together with the water generate ROS that promotes the DNA lesions; 2. in another way the lesions can be generated by the formation of ROS due to the internal chemical structure of the flavonoid molecule due to the quantity and location of hydroxyl groups, and so producing the DNA lesions, those lesions can be directly (suggested by the in vitro experiments) or indirectly done (supported by the experiments using the CC bacterial strains)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Colon-specific drug delivery systems have attracted increasing attention from the pharmaceutical industry due to their ability of treating intestinal bowel diseases (IBD), which represent a public health problem in several countries. In spite of being considered a quite effective molecule for the treatment of IBD, mesalazine (5-ASA) is rapidly absorbed in the upper gastrointestinal tract and its systemic absorption leads to risks of adverse effects. The aim of this work was to develop a microparticulate system based on xylan and Eudragit® S- 100 (ES100) for colon-specific delivery of 5-ASA and evaluate the interaction between the polymers present in the systems. Additionaly, the physicochemical and rheological properties of xylan were also evaluated. Initially, xylan was extracted from corn cobs and characterized regarding the yield and rheological properties. Afterwards, 10 formulations were prepared in different xylan and ES100 weight ratios by spray-drying the polymer solutions in 0.6N NaOH and phosphate buffer pH 7.4. In addition, 3 formulations consisting of xylan microcapsules were produced by interfacial cross-linking polymerization and coated by ES100 by means of spray-drying in different polymer weight ratios of xylan and ES100. The microparticles were characterized regarding yield, morphology, homogeneity, visual aspect, crystallinity and thermal behavior. The polymer interaction was investigated by infrared spectroscopy. The extracted xylan was presented as a very fine and yellowish powder, with mean particle size smaller than 40μm. Regarding the rheological properties of xylan, they demonstrated that this polymer has a poor flow, low density and high cohesiveness. The microparticles obtained were shown to be spherical and aggregates could not be observed. They were found to present amorphous structure and have a very high thermal stability. The yield varied according to the polymer ratios. Moreover, it was confirmed that the interaction between xylan and ES100 occurs only by means of physical aggregation

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Hormone therapy is an important tool in the treatment of breast cancer and tamoxifen represents one of the most important drugs used in this type of treatment. Recently other drugs based on the inhibition of aromatase had been developed, this enzyme is responsible for the synthesis of estrogenic esteroids from the androgenic ones. The objective of this study would be the development of a quantitative cytological model of murine estral analysis that allowed the characterization of different hormone drugs effect over vaginal epithelium. The technique of monochromatic staining with Evans blue (C.I. 23860) showed to be efficient in the qualitative and quantitative classification of the cycle. It had been observed differences in the cytological standard of animals submitted to the studied drugs; tamoxifen presented a widening of phases of lesser maturation (diestrais), while anastrozole and exemestane increased the duration of the phases of larger maturation (estrais). The data were analysed through a cubical non linear regression (spline) which allowed a better characterization of the drugs, suggesting a proper cytological profile to the antagonism of the estrogen receptor (tamoxifen), aromatase competition (anastrozole) and inhibition of the enzyme (exemestane)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Given the great diversity of fishes, the Order Tetraodontiformes stands to show genetic and morphological characteristics enough singular. The fishes of this order have a compact DNA which favors molecular studies, as well as comparisons with more basal species. Model of genome evolution, there are still many gaps in knowledge about their chromosomal patterns and how evolutionary rearrangements influence the marked variation in DNA content of this order. In view of this, we present cytogenetic analyzes of the species Acanthostracion quadricornis (Ostraciidae), A. polygonius (Ostraciidae) Melichthys niger (Balistidae) Cantherhines macrocerus (Monacanthidae) and C. pullus (Monacanthidae), Lagocephalus laevigatus, Colomesus psittacus and Canthigaster figueiredoi (Tetraodontidae), to contribute with cytogenetic data for this group. The analysis was performed by C-banding, Ag-RONs, coloring with base-specific fluorochromes DAPI-CMA3, restriction enzymes AluI, EcoRI, TaqI, PstI and HinfI and in situ hybridization with probes for ribosomal DNA 18S and 5S. The heterochromatic ultrastructure of A. quadricornis and A. polygonius revealed a outstanding heterochromatin content, which may indicate that the accumulation or loss of extensive heterochromatin content could be responsible for large variations in genomic content displayed in different Tetraodontiformes families. The species Cantherhines macrocerus, C. pullus (Monacanthidae) and Melichthys niger (Balistidae) shows a huge karyotypic similarity both numerically and structural. L. laevigatus showed similar cytogenetic features (2n = 44 and single RONs) to the species of the genus Takifugu, which reinforces the idea of their phylogenetic relationships. C. psittacus presented the highest diploid number described for the family (2n = 56) and large amount of HC, features that related with its sister family Diodontidae. Cytogenetic analysis in C. figueiredoi revealed heterochromatic polymorphisms, RONs multiple and Bs chromosomes. These events are rare in marine fishes, and are possibly associated with the strong restructuring and genomic reduction that this family has been suffered. These features, plus the morphological and molecular data suggests that these species share the same ancestral branch, with a possible monophyletic origin. In this study, new contributions to the knowledge of evolutionary patterns facing by Tetraodontiformes are provided and discussed under cytotaxonomyc, genomic and evolutionary perspectives.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Cytogenetic studies in fish have been contributed significantly to a better understanding of the marine biodiversity, presenting information related to characterization, evolution and conservation of species e fisheries stocks. Among the marine species which cytogenetic data are less well known pelagic forms are detached, that despite the economic importance and conservation efforts have been suffering great pressure from the artisanal and industrial fisheries. The present work characterized cytogenetically six species of large pelagic fish in the Atlantic, belonging to the Order Perciformes, among them, four species of Scombridae, Thunnus albacares, T. obesus, Scomberomorus brasiliensis and Acanthocybium solandri and two Coryphaenidae, Coryphaena equiselis and C. hippurus using Classical cytogenetic methods as conventional staining, C-banding and Ag-NORs and molecular through staining fluorochromes AT and GC-specific and mapping of ribosomal multigene families, 18S and 5S. The identification of phylogenetic patterns and cytotaxonomic markers between the species and the presence of sex chromosomes in at least one species of Coryphaenidae, are particularly useful in the formulating of phylogenetic hypotheses, as well as comparisons between groups and populations

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The reinforced concrete structures are largely used in buildings worldwide. Upon the occurrence of fire in buildings, there is a consensus among researchers that the concrete has a high resistance to fire, due mainly to its low thermal conductivity. However, this does not mean that this material is not affected by exposure to high temperatures. Reduction of the compressive strength, modulus of elasticity, discoloration and cracking, are some of the effects caused by thermal exposure. In the case of concretes with higher resistance occurs even desplacamentos explosives, exposing the reinforcement to fire and contributing to reducing the support capacity of the structural element. Considering the above, this study aims to examine how the compressive strength and porosity of concrete are affected when subjected to high temperatures. Were evaluated concrete of different resistances, and even was the verified if addition fibers of polyethylene terephthalate (PET) in concrete can be used as an alternative to preventing spalling. The results indicated that explosive spalling affect not only high strength concrete whose values of this study ranged from 70 to 88 MPa, as well as conventional concrete of medium strength (52 MPa) and the temperature range to which the concrete begins to suffer significant changes in their resistance is between 400 º C and 600 º C, showing to 600 º C a porosity up to 188% greater than the room temperature