18 resultados para wax glands
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
Benznidazole, a drug with specific anti-Trypanosoma cruzi activity, is used in the treatment of Chagas’ disease. The radiopharmaceutical sodium pertechnetate (Na99mTcO4) is used to obtain diagnostic images of the stomach, thyroid, parathyroids, salivary glands, brain and in the study of esophageal reflux and blood flow. This study aimed at evaluating in vivo the influence of benznidazole treatment on the sodium pertechnetate biodistribution in Wistar rats. The percentage of radioactivity per gram (%ATI/g) of various organs (brain, heart, esophagus, stomach, small intestine, large intestine, spleen, liver, muscle and blood) was determined. Comparing the treated rats with the controls, we observed that sodium pertechnetate biodistribution did not change when administered to rats treated for thirty days with benznidazole
Resumo:
Visceral leishmaniasis (VL) has a wide geographical distribution in tropical and subtropical areas of the planet, which is a protozoan parasite of the genus Leishmania. This pathogen is transmitted to the host through the sandflies bite, with its saliva, the immune response that leads to both. In the state of Rio Grande do Norte, 85% of the sand flies captured is Lutzomyia longipalpis, but the second most abundant, Lutzomyia evandroi, it deserves emphasis because its wide distribution and eclectic behavior. The exposure of people living in endemic areas for the insect vector VL greatly increases the chances of infection. This study aimed to evaluate aspects of the epidemiological profile of VL in endemic areas of human and nonendemic in the metropolitan area of Natal, as well as verify the abundance and seasonal fluctuations of sandflies species in two counties endemic for VL. Were collected in the municipalities of Nísia Floresta, Parnamirim, São Gonçalo do Amarante and Macaíba, of which groups of females were separated for further dissection of the salivary glands and identification of species. The blood samples used were from individuals of two Natal s districts where it has never been reported cases of VL and neighborhoods of Parnamirim applicants who present cases of VL. In the municipality of Nísia Floresta, the most abundant species was L. evandroi with 38.39%, followed by L. longipalpis with 36.22%, L. walkeri 19.67% L. lenti 3.81%, L. wellcomei 1.39% and L. whitmani 0.52%. Already in Parnamirim the proportions were L. walkeri with 73.15%, L. evandroi with 10.55%, L. wellcomei 7.63%, L. longipalpis 6.37%, L. whitmani 1.46%, L. sordellii 0.52%, L. intermedia 0.21 and L. shanonni 0.1%. In both municipalities was observed higher abundance of species distributed in the initial months of the year, as February and March. The study showed that no difference in exposure to the vector of VL among individuals from endemic and non endemic area for this disease. But there are differences in exposure between individuals of L. longipalpis and L. evandroi, confirming the great powers of the first vector. It was also characterized as predominant phenotype in the population of endemic areas who had negative serologic responses to antigens of Leishmania and result in negative Montenegro skin test (DTH), indicating that much of the population hasn t been bitten by infected insects
Resumo:
Food habits and morpho-histology of the digestive tract of marbled swamp eel, Synbranchus marmoratus (Block, 1917) were investigated. The fish samples were captured during August, 2007 to July, 2008 in the Marechal Dutra reservoir, Acari, Rio Grande do Norte. The rain fall data was obtained from EMPARN. The fish captured, were measured, weighed, dissected, eviscerated and individual stomach weights were registered. The stomach contents analyses were carried out based on volumetric method, points, frequency of occurrence and applying the Index of Relative Importance. The degrees of repletion of the stomachs were determined besides the Index of Repletion relating to feeding activity variations and frequency of ingestion during the rainy and dry seasons. The rainfall varied from 0 mm a 335 mm with a mean value of 71.62 mm. Highest rainfall of 335.5 mm was registered in March, 2008 and August to December was the dry period. During the dry period the study species presented high degrees of repletion of the stomachs, with a peak value in the month of September (mean = 4.54; ± SD = 0.56). The minimum mean value of = 3.99 ± SD = 0.25 was registered in the month of May during the rainy period. The stomach contents of S. marmoratus registered show that this fish prefers animals, 78.22% of crustaceans 2.85% of mollusks, 3.25% of fish, 1.4% of insects and 13.5% of semi-digested organic matter, thus characterizing the study species as a carnivore with a preference for crustaceans. The morpho-histological aspects of the digestive tract of S. marmoratus indicate that the mouth is terminal adapted to open widely, thin lips with taste buds, small villiform teeth forming a single series on maxillas, four pairs of branchial arches with short and widely spaced branchial rays. The oesophagus is short and cylindrical with a small diameter. The oesophagus wall is thick with mucas surface and internal parallel folds. The stomach is retilinical in form, presenting cardiac, caecal and pyloric portions. The caecal portion is long and is intermediary in position between the cardiac and pyloric portions. The cardiac portion of the stomach is short and cylindrical formed of simple epithelial cylindrical mucus cells. The caecal portion is long with narrow walls, a big cavity and smaller folds which give rise to gastric glands. The phyloric portion has no glands and primary or secondary mucas folds. The morphohistological aspects of the digestive tract of S. marmoratus indicate its adaptation to a carnivorous feeding habit
Resumo:
A presente pesquisa visa entender os fatores que explicam a manutenção dos aspectos artesanais no extrativismo da cera de carnaúba em Limoeiro do Norte. Justificamos a exploração desse tema pelo fascínio do autor pelo tema e por ser esse recurso ainda uma importante fonte de renda para produtores e trabalhadores rurais no respectivo município. Objetivamos nessa pesquisa identificar as razões pelas quais a atividade mantém seu padrão tecnológico intacto. Primeiro objetivamos uma descrição do processo produtivo da cera, tanto no passado, quanto no presente, comparando estes momentos e ressaltando o caráter artesanal da atividade, além de analisar a importância atual da atividade para aqueles que ainda lidam com esse tipo de produção, bem como procuramos revelar estrutura histórica e institucional que permeia a lógica e as escolhas destes produtores, a qual pode explicar a preservação destes aspectos artesanais. Utilizando o referencial teórico do institucionalismo, explicamos que a preservação destes aspectos artesanais, ocorre em virtude da prevalência de determinadas instituições, como a memória coletiva cultivada entre os rendeiros idosos e resistentes, a concentração fundiária, responsável pelo arrendamento e também as restritas possibilidades de investimento e poupança no processo produtivo, em face do baixo nível de renda de produtores, os quais com um produto pouco competitivo no mercado, pouco podem fazer para inovar tecnologicamente.
Resumo:
This paper aims to present the feasibility of using a composite using discarded material from the cultivation of banana tree (pseudostem), which is fibrillated together with synthetic resin replacing glass fiber to be used in structural elements that do not demand large mechanical stress such as reservoirs, troughs, domes, sewage pipes etc.. For this, there were studies about the mechanical properties of a composite made with polyester resin and fiber of banana tree (Musa sp, musac), in which the splints were removed from the pseudostem, being made fibrillation by hand, with the aid of a brush steel, followed by natural drying. After treatment for cleaning and removal of wax, the fiber was cut into pieces of approximately 60 mm to 100 mm, for, together with synthetic resin, make cards of a features fiber composite with random orientation relative to the weight of the resin. We used three different percentages of fiber (3%, 6% and 9%), in order to make a comparative study between them and what would be the one with the best performance. Were manufactured specimens of each material and then subjected to uniaxial tensile tests, three point bending, moisture absorption and thermal characteristics. The results show that, in general, the use of banana tree fiber is feasible simply by an improvement in the production process (machining of the procedure) and greater care in the manufacture of parts
Resumo:
In the present research work, composites were prepared using pine apple leaf fibres (PALF) as reinforcement with unsaturated polyester resin as matrix, incorporating with fire retardant at different compositions. The PALF was obtained from the decortication of pine apple leaves obtained from Ramada 4 from Ielmo Marinho in the State of Rio Grande do Norte. The unsaturated polyester resin and the catalyzer were bought from the local establishment. The fire retardant, aluminium tri-hydroxide - Al(OH)3 was donated by Alcoa Alumínio S.A and was used in the proportions of 20%, 40% and 60% w/w. Initially the fibres were treated with 2% NaOH for 1 hour, to remove any impurities present on the fibre surface, such as wax, fat, pectin and pectate, in order to have a better adsorption of the fibres with the matrix as well as the flame retardant. The fibre mat was prepared in a mat preparator by immersion, developed in the Textile Engineering Laboratory, at the UFRN. The composites (300x300x3 mm) were prepared by compression molding and the samples (150x25x3 mm) for analysis of the properties were cut randomly using a laser cutter. Some of the cut samples were used to measure the smoke emission and fire resistance using UL94 standard. Mechanical tension-extension and flexural properties were carried in CTGás RN and the Laboratório de Metais e Ensaios Mecânicos Engenharia de Materiais UFRN , as well as SEM studies were carried out at Núcleo de Estudos em Petróleo e Gás Natural - UFRN . From the observed results, it was noted that, there was no marked influence of the fire retardant on the mechanical properties. Also in the water absorption test, the quantity of water absorbed was less in the sample with higher concentration of fire retardant. It was also observed that the increase in the proportion of the fire retardant increased the time of burning, may be due to the compactness of the composite due to the presence of fire retardant as a filling material even though it was meant to reduce the rate of inflammability of the composite
Resumo:
The formation of paraffin deposits is common in the petroleum industry during production, transport and treatment stages. It happens due to modifications in the thermodynamic variables that alter the solubility of alkanes fractions present in petroleum. The deposition of paraffin can provoke significant and growing petroleum losses, arriving to block the flow, hindering to the production. This process is associated with the phases equilibrium L-S and the stages and nucleation, growth and agglomeration the crystals. That process is function of petroleum intrinsic characteristics and temperature and pressure variations, during production. Several preventive and corrective methods are used to control the paraffin crystallization, such as: use of chemical inhibitors, hot solvents injection, use of termochemistry reactions, and mechanical removal. But for offshore exploration this expensive problem needs more investigation. Many studies have been carried through Wax Appearance Temperature (WAT) of paraffin; therefore the formed crystals are responsible for the modification of the reologics properties of the oil, causing a lot off operational problems. From the determination of the WAT of a system it is possible to affirm if oil presents or not trend to the formation of organic deposits, making possible to foresee and to prevent problems of wax crystallization. The solvent n-paraffin has been widely used as fluid of perforation, raising the production costs when it is used in the removal paraffin deposits, needing an operational substitute. This study aims to determine the WAT of paraffin and the interference off additives in its reduction, being developed system paraffin/solvent/surfactant that propitiates the wax solubilization. Crystallization temperatures in varied paraffin concentrations and different solvents were established in the first stage of the experiments. In the second stage, using the methodology of variation of the photoelectric signal had been determined the temperature of crystallization of the systems and evaluated the interferences of additives to reduction of the WAT. The experimental results are expressed in function of the variations of the photoelectric signals during controlled cooling, innovating and validating this new methodology to determine WAT, relatively simple with relation the other applied that involve specific equipments and of high cost. Through the curves you differentiate of the results had been also identified to the critical stages of growth and agglomeration of the crystals that represent to the saturation of the system, indicating difficulties of flow due to the increase of the density
Resumo:
The constant search for biodegradable materials for applications in several fields shows that carnauba wax can be a viable alternative in the manufacturing of biolubricants. Carnauba wax is the unique among the natural waxes to have a combination of properties of great importance. In previous studies it was verified the presence of metals in wax composition that can harm the oxidative stability of lubricants. Considering these factors, it was decided to develop a research to evaluate iron removal from carnauba wax, using microemulsion systems (Me) and perform the optimization of parameters, such as: extraction pH, temperature, extraction time, among others. Iron concentration was determined by atomic absorption and, to perform this analysis, sample digestion in microwave oven was used, showing that this process was very efficient. It was performed some analysis in order to characterize the wax sample, such as: attenuated total reflectance infrared spectroscopy (ATR-IR), thermogravimetry (TG), differential scanning calorimetry (DSC), energy dispersive X-ray fluorescence (EDXRF), scanning electron microscopy (SEM) and melting point (FP). The microemulsion systems were composed by: coconut oil as surfactant, n-butanol as cosurfactant, kerosene and/or heptanes as oil phase, distilled water as water phase. The pH chosen for this study was 4.5 and the metal extraction was performed in finite experiments. To evaluate Me extraction it was performed a factorial design for systems with heptane and kerosene as oil phase, also investigating the influence of temperature time and wax/Me ratio, that showed an statistically significant answer for iron extraction at 95% confidence level. The best result was obtained at 60°C, 10 hours contact time and 1: 10 wax/Me ratio, in both systems with kerosene and heptanes as oil phase. The best extraction occurred with kerosene as oil phase, with 54% iron removal
Resumo:
The flow assurance has become one of the topics of greatest interest in the oil industry, mainly due to production and transportation of oil in regions with extreme temperature and pressure. In these operations the wax deposition is a commonly problem in flow of paraffinic oils, causing the rising costs of the process, due to increased energy cost of pumping, decreased production, increased pressure on the line and risk of blockage of the pipeline. In order to describe the behavior of the wax deposition phenomena in turbulent flow of paraffinic oils, under different operations conditions, in this work we developed a simulator with easy interface. For that we divided de work in four steps: (i) properties estimation (physical, thermals, of transport and thermodynamics) of n-alkanes and paraffinic mixtures by using correlations; (ii) obtainment of the solubility curve and determination the wax appearance temperature, by calculating the solid-liquid equilibrium of parafinnic systems; (iii) modelling wax deposition process, comprising momentum, mass and heat transfer; (iv) development of graphic interface in MATLAB® environment for to allow the understanding of simulation in different flow conditions as well as understand the matter of the variables (inlet temperature, external temperature, wax appearance temperature, oil composition, and time) on the behavior of the deposition process. The results showed that the simulator developed, called DepoSim, is able to calculate the profile of temperature, thickness of the deposit, and the amount of wax deposited in a simple and fast way, and also with consistent results and applicable to the operation
Resumo:
The WAT is the temperature at the beginning of the appearance of wax crystals. At this temperature the first wax crystals are formed by the cooling systems paraffin / solvents. Paraffins are composed of a mixture of saturated hydrocarbons of high molecular weight. The removal of petroleum from wells and the production lines means a surcharge on produced oil, thus solubilize these deposits formed due to modifications of thermodynamics has been a constant challenge for companies of oil exploration. This study combines the paraffin solubilization by microemulsion systems, the determination of WAT systems paraffin / solvent and performance of surfactant in reducing the crystallization. We used the methods: rheological and the photoelectric signal, validating the latter which was developed to optimize the data obtained due to sensitivity of the equipment used. Methods developed for description of wax precipitation are often in poor agreement with the experimental data, they tend to underestimate the amount of wax at temperatures below the turbidity point. The Won method and the Ideal solution method were applied to the WAT data obtained in solvent systems, best represented by the second interaction of Won method using the solvents naphtha, hexane and LCO. It was observed that the results obtained by WAT photoelectric signal when compared with the viscosity occur in advance, demonstrating the greatest sensitivity of the method developed. The ionic surfactant reduced the viscosity of the solvent systems as it acted modifying the crystalline structure and, consequently, the pour point. The curves show that the WAT experimental data is, in general, closer to the modeling performed by the method of Won than to the one performed by the ideal solution method, because this method underestimates the curve predicting the onset of paraffin hydrocarbons crystallization temperature. This occurs because the actual temperature measured was the crystallization temperature and the method proposes the fusion temperature measurement.
Resumo:
Glandular atrophy is one of several alterations which can aflict the salivary glands, caused generally by obstructive lesions such as sialo1ithiasis, infections or compression by neoplastic processes arnong others. In this work, a morphological and immunohistochemical study was carried out in rat parotid glands, which were submitted to obstruction of the main excretory duct suffering atrophy at varied time intervals, with the aim of appraising the behavior of myoepithelial cells during the process of glandular atrophy. It was analized the immunohistochemical expression of calponin which detects myoepithelial cells in the parotids of 28 animaIs, which were divided into 7 groups, each one made up of 4 rats, afier the ductal ligature procedure, in the following time intervals: zero hour (control), 24 hours, 7, 15, 21, 30 and 60 days. Analysis of the immunohistochemicaI profile was carried through in which the calponin expression was veritied through its distribution pattem and numericaI index. All specimens exhibited positivity for calponin in myoepithelial cells which were distributed around the acini and the ductaI structures, a small number of positiveIy marked cells being detected in the controI group and in the 24-hour group when compared to subsequent ones, where it was perceived a Iarge increase in the number of positiveIy marked cens, mainly surrounding the ductiform structures which originated during the obstruction time. Upon application of statistical tests it was verified that the rise in the number the myoepithelial positive cells for calponin, when the control groups (zero hour) was compared to the 7, 15,21, 30 and 60-day groups afier obstruction, was statistica1ly significant. It was concluded then that the detected rise probably carne about due to an elevation in the rate of proliferation of the myoepitheliaI cells subsequent to the ductal obstruction, associated with a growing resistance of these cells to glandular atrophy.
Resumo:
Central giant cell lesion (CGCL) and peripheral giant cell lesion (PGCL) of the jaws have a distinct clinical behavior, although they share histopathologic features. It is still unclear whether these clinical differences are supported by a distinct pattern of immunoexpression of markers for multinucleated giant cells (GC) and mononuclear cells (MC). The purpose of this study was to compare the immunohistochemical expression of VEGF, MMP-9 in CG and MC and measure the vascularization by vWF to check whether there are differences in expression of these biomarkers between CGCL and PGCL. Paraffin wax blocks of 20 cases of LCCG and 20 LPCG were retrieved. MMP-9 immunoreactivity was greater in the CM of PGCL compared to VEGF (p<0.05). VEGF expression was greater in the CM of CGCL compared to PGCL (p<0.05) and it was greater in the overall expression of CGCL compared to PGCL (p<0.05). Vascularity was quantified by microvascular counting (MVC). MVC was greater in the PGCL compared CGCL (p<0.05). MMP-9 showed a greater tendency of expression in CGCL, though was not significant (p>0.05). We tested correlation between the proteins studied in each group and found a significant negative correlation between VEGF and vWF in CGCL (p<0.05). These results suggest that there are differences in the expression of VEGF in CM and overall expression between the lesions, although no statistically significant difference in the overall expression of the MMP-9. Then, there was a trend in increased expression of MMP-9 and VEGF in CGCL, possibly by the involvement of both proteins in osteoclastogenesis. Additionally, the results of this study indicate a higher degree of vascularization in PGCL compared to CGCL, fact that can be directly linked to the reactive nature of the PGCL, where the inflammatory process with its rich angiogenesis contributes significantly to these findings.
Resumo:
The expression of glucose transporter protein 1 (GLUT-1), as well the angiogenesis has been associated to clinical behavior and aggressiveness in tumors of various origin. It is believed that the expression of this protein denotes metabolic demand of the tumor cells and, thus its influence upon the formation of new blood vessels. Pleomorphic adenoma (PA) and the adenoid cystic carcinoma (ACC) and mucoepidermoid carcinoma (MEC) represent, respectively, the most commom benign and malignant tumors of salivary glands. The aim of this study was to analyze and compare the immunohistochemical expression of GLUT-1 and its correlation with angiogenesis in cases of PAs, ACCs and MECs considering their histological grades. The sample consisted of 20 PAs, 20 ACCs and 10 MECs. The cases were analyzed and classified according to their histological grades. The expression of GLUT-1 was evaluated in the parenchyma lesions, establishing the percentage of immunopositive cells, according to the following scores: 0 (no cell immunomarked), 1 (up to 25% of tumor cells immunostained), 2 (25 - 50% of tumor cells immunostained) and 3 (more than 50% of tumor cells immunostained). The angiogenic index was analyzed by counting the microvessels immunostained by anti-CD34 antibody, in 5 fields (200X). The analysis of the expression of GLUT-1 in tumor parenchyma showed statistically significant differences between benign and malignant groups (p = 0.022). The average number of microvessels in PAs was 40.4, 21.2 in ACCs and 66.5 in MECs, with significant differences between groups (p <0.001). When compared to the expression of GLUT-1 and angiogenic index as a whole, there was no significant correlation between the number of microvessels and the expression of GLUT-1 (r = 0.211, p = 0.141). In conclusion, the results of this study suggest not only that differences in biological behavior between PAs, ACCs and MECs may be associated to the expression of GLUT-1, but also that benign and malignant salivary gland present differences in the average number of microvessels, with higher levels considered more aggressive tumors. Furthermore, the number of newly formed microvessels can be independent of the metabolic demand of the tumor cells
Resumo:
The balance between the expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) has been related to various physiological and pathological processes, including salivary gland morphogenesis and tumor invasion and metastasis processes. Pleomorphic adenoma (PA) and adenoid cystic carcinoma (ACC) respectively represent benign and malignant neoplasias of salivary glands. Although they share the same cell origin, they present distinct biological behavior. The aim of this study was to compare the immunohistochemical expression of MMPs -2, -7, -9 and -26, and of TIMPs -1 and -2, in cases of PA and ACC of minor salivary glands. Twenty cases of PA and twenty cases of ACC were assessed according to the presence, intensity and location of MMPs and TIMPs in the tumor parenchyma. Most of the PAs and ACCs presented a high expression of MMP -2, -7, -9 and -26 and of TIMP -1 and -2, predominantly located in tumor cells. There was no significant difference in the expression of MMPs -2 (p=0.359), -7 (p=0.081) and -26 (p=0.553), as well as of TIMPs -1 (p=0.657) and -2 (p=0.248), between the parenchyma of PAs and ACCs. However, MMP-9 showed a significant difference of expression between the two tumors, with the ACC showing more intense marking for this gelatinase (p=0.041). The strong expression of MMP-9 observed in the parenchyma suggests that this gelatinase may play an important role in the biological behavior of these tumors. On the other hand, although there was no significant difference between the marking of MMP -2, 7 and 26 in the studied tumors, the data, when analyzed as a whole, suggest that these proteases may take part in the process of tissue remodeling in both tumors, but do not present a direct relation with the pattern of aggressiveness of ACC. Nonetheless, matrilisins may indirectly influence the behavior of this tumor due to their capacity of activating MMP-9, strongly expressed in the parenchyma of ACC
Resumo:
Pleomorphic adenoma and adenoid cystic carcinoma (ACC) consist benign and malignant neoplasm from salivary gland, respectively. These neoplasms share some characteristics, such as cellular origin and considerable production of extracellular matrix, however, with distinct biological behavior. The aim of the present study was to compare the expression of D2E1, D3E1 e D5E1 integrins in pleomorphic adenoma from minor and major salivary glands and ACCs. Furthermore, it was investigated possible differences in the expression of these integrins according to histological subtypes of ACC. Fourteen cases of pleomorphic adenoma from major salivary gland, fourteen cases from minor salivary gland and ten cases of ACC were selected. It was taken into consideration the presence or absence, localization and intensity of integrin immunoexpression. The cases of pleomorphic adenoma were grouped in order to compare the expression between the distinct neoplasms. It was observed a highly significant difference (p<0,0001) in relation to D2E1 integrin between the neoplasms since pleomorphic adenoma showed a pronounced immunostaining. It was not possible to perform statistical tests considering the D2E1 integrin expression; nevertheless, it could be observed a tendency of higher staining in pleomorphic adenoma. For comparative reasons the cases ACCs were divided in two groups: solid and tubular/cribriform. It was not detected significant differences in regard to D2E1 integrin; and statistical analysis could not be realized in relation to D3E1 and D5E integrin expression. However, it was also verified a tendency of absence or reduced expression in the solid subtype. It can be concluded that the reduced D2E1 integrin expression observed in CACs may be related to a lesser degree of cell differentiation in this neoplasm and the reduced D5E1 integrin expression can be associated with aggressive biological behavior. Moreover, the absence and/or reduced expression of the studied integrins in solid ACC suggests a role in pathogenesis and more aggressive biological behavior of this histological subtype