964 resultados para mononuclear and isolated TiOx
Resumo:
Aquaporins and aquaglyceroporins mediate the transport of water and solutes across biological membranes. Saccharomyces cerevisiae Fps1 is an aquaglyceroporin that mediates controlled glycerol export during osmoregulation. The transport function of Fps1 is rapidly regulated by osmotic changes in an apparently unique way and distinct regions within the long N- and C-terminal extensions are needed for this regulation. In order to learn more about the mechanisms that control Fps1 we have set up a genetic screen for hyperactive Fps1 and isolated mutations in 14 distinct residues, all facing the inside of the cell. Five of the residues lie within the previously characterized N-terminal regulatory domain and two mutations are located within the approach to the first transmembrane domain. Three mutations cause truncation of the C-terminus, confirming previous studies on the importance of this region for channel control. Furthermore, the novel mutations identify two conserved residues in the channel-forming B-loop as critical for channel control. Structural modelling-based rationalization of the observed mutations supports the notion that the N-terminal regulatory domain and the B-loop could interact in channel control. Our findings provide a framework for further genetic and structural analysis to better understand the mechanism that controls Fps1 function by osmotic changes.
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Almost a decade has passed since the objectives and benefits of autonomic computing were stated, yet even the latest system designs and deployments exhibit only limited and isolated elements of autonomic functionality. In previous work, we identified several of the key challenges behind this delay in the adoption of autonomic solutions, and proposed a generic framework for the development of autonomic computing systems that overcomes these challenges. In this article, we describe how existing technologies and standards can be used to realise our autonomic computing framework, and present its implementation as a service-oriented architecture. We show how this implementation employs a combination of automated code generation, model-based and object-oriented development techniques to ensure that the framework can be used to add autonomic capabilities to systems whose characteristics are unknown until runtime. We then use our framework to develop two autonomic solutions for the allocation of server capacity to services of different priorities and variable workloads, thus illustrating its application in the context of a typical data-centre resource management problem.
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Half a decade has passed since the objectives and benefits of autonomic computing were stated, yet even the latest system designs and deployments exhibit only limited and isolated elements of autonomic functionality. From an autonomic computing standpoint, all computing systems – old, new or under development – are legacy systems, and will continue to be so for some time to come. In this paper, we propose a generic architecture for developing fully-fledged autonomic systems out of legacy, non-autonomic components, and we investigate how existing technologies can be used to implement this architecture.
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Type 2 diabetes is an insidious disorder, with micro and/or macrovascular and nervous damage occurring in many patients before diagnosis. This damage is caused by hyperglycaemia and the diverse effects of insulin resistance. Obesity, in particular central obesity, is a strong pre-disposing factor for type 2 diabetes. Skeletal muscle is the main site of insulin-stimulated glucose disposal and appears to be the first organ that becomes insulin resistant in the diabetic state, with later involvement of adipose tissue and the liver. This study has investigated the use of novel agents to ameliorate insulin-resistance in skeletal muscle as a means of identifying intervention sites against insulin resistance and of improving glucose uptake and metabolism by skeletal muscle. Glucose uptake was measured in vitro by cultured L6 myocytes and isolated muscles from normal and obese diabetic ob/ob mice, using either the tritiated non-metabolised glucose analogue 2-deoxy-D-glucose or by glucose disposal. Agents studied included lipoic acid, isoferulic acid, bradykinin, lipid mobilising factor (provisionally synonymous with Zinca2 glycoprotein) and the trace elements lithium, selenium and chromium. The putative role of TNFa in insulin resistance was also investigated. Lipoic acid improved insulin-stimulated glucose uptake in normal and insulin resistance murine muscles, as well as cultured myocytes. Isoferulic acid, bradykinin and LMF also produced a transient increase in glucose uptake in cultured myocytes. Physiological concentrations of TNFa were found to cause insulin resistance in cultured, but no in excised murine muscles. The effect of the M2 metabolite of the satiety-inducing agent sibutramine on lipolysis in excised murine and human adipocytes was also investigated. M2 increased lipolysis from normal lean and obese ob/ob mouse adipocytes. Arguably the most important observation was that M2 also increased the lipolytic rate in adipocytes from catecholamine resistant obese subjects. The studies reported in this thesis indicate that a diversity of agents can improve glucose uptake and ameliorate insulin resistance. It is likely that these agents are acting via different pathways. This thesis has also shown that M2 can induce lipolysis in both rodent and human adipocytes. M2 hence has potential to directly reduce adiposity, in addition to well documented effects via the central nervous system.
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Impaired insulin action (insulin resistance) is a key factor in the pathogenesis of diabetes mellitus. To investigate therapeutic targets against insulin resistance, this thesis explores the mechanism of action of pharmacological agents and exogenous peptides known or suspected to modify insulin action. These included leptin, a hormone primarily involved in the regulation of body weight; sibutramine, an antiobesity agent; plant-derived compounds (pinitol and chamaemeloside) and agents known to affect insulin sensitivity, e.g. metformin, tolbutamide, thiazolidinediones, vanadyl sulphate and thioctic acid. Models used for investigation included the L6 skeletal muscle cell line and isolated skeletal muscles. In vivo studies were undertaken to investigate glycaemia, insulinaemia, satiety and body weight in streptozotocin-induced diabetic mice and obese (ob/ob) mice. Leptin acutely altered insulin action in skeletal muscle cells via the short form of the leptin receptor. This direct action of leptin was mediated via a pathway involving PI 3-kinase but not Jak2. The active metabolites of sibutramine had antidiabetic properties in vivo and directly improved insulin sensitivity in vitro. This effect appeared to be conducted via a non-PI 3-kinase-mediated increase in protein synthesis with facilitated glucose transport, and was independent of the serotonin and noradrenaline reuptake inhibition produced by sibutramine. Pinitol (a methyl inositol) had an insulin mimetic effect and was an effective glucose-lowering agent in insulinopenic states, acting directly on skeletal muscle. Conversely chamaemeloside appeared to improve glucose tolerance without directly altering glucose transport. Metformin directly increased basal glucose uptake independently of PI 3-kinase, possibly via an increase in the intrinsic activity of glucose transporters. Neither tolbutamide nor thiazolidinediones directly altered insulin sensitivity in L6 skeletal muscle cells: however vanadyl sulphate and thioctic acid increased glucose transport but appeared to exert toxic effects at therapeutic concentrations. Examination of glucose transport in skeletal muscle in this thesis has identified various components of post-receptor insulin signalling pathways which may be targeted to ameliorate insulin resistance. Type 2 Diabetes Mellitus Obesity L6 Skeletal Muscle Cells Glucose Transport Insulin Signalling 2
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Despite being areas of socioeconomic and ecological importance, the reef environments in northeastern Brazil have been suffering with cluttered tourism impacts, such as trampling, activity that leads to decrease in abundance of organisms, especially benthic, and loss of biodiversity. The objectives of this study were 1) to characterize the benthic community in the shallow sandstone reef of Pirangi/RN, identifying patterns of zonation, and 2) evaluate its process of structuring under different degrees of impact of trampling, providing information to the proper use of the area. Data on abundance of organisms, the percentage coverage of the substrate and physic-chemical parameters were collected. The formation of two zones on the reef was observed: one that considers submerged areas and ones with shorter time of exposure, lower roughness and higher heterogeneity in the coverage of the substrate, with a predominance of sand, foliose algae, rodolit, being related to organisms such as gastropods, crabs and sea-urchin; the second zone comprises areas with longer time of exposure, greater roughness and predominance of bedrock uncovered, being associated with organisms such as barnacles, gastropods, bivalves and crabs. It is concluded that the studied reef presents its own zonation pattern, influenced by both the time of immersion and the substrate characteristics, such as roughness and type of coverage. To answer the second objective of this study, four experimental blocks were mounted on each of the three areas of different intensities of trampling, containing the following treatments: control (isolated from trampling), shaved isolated, trampling and shaved trampling, with data collection by 11 months. The data in abundance, diversity indices and living coverage of the substrate were compared between areas and treatments. The results showed that at the trampling areas, at the end of the experiment, differences were observed between the intensities of the impact, where higher values of abundance and richness of mobile fauna and richness of live coverage (ANOVA, p <0.05) were found in the area of higher trampling intensity. For fauna withdrawal of trampled scraped treatments, it was observed in the area of greatest impact that the abundance of small benthic invertebrates is more than three times smaller than that at the area of intermediate trampling (ANOVA, p <0.05). Initial isolated areas and final ones differed only as to the percentage of live coverage, with an increase of 35% at the end of this experiment. As for the areas that were completely scraped and isolated at the end of the experiment was observed an increase in the percentage of live coverage of 11.11% compared to the initial amount in the area of intermediate impact and 37.5% in the area with greater impact, indicating recovery of the area. It is suggested that the current use of the reef of Pirangi be reviewed, with a decentralization of trampling, or a decrease in visits, so that it does not occur at high intensities
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Envenomation caused by venomous animals, mainly scorpions and snakes, are a serious matter of public health. Tityus serrulatus is considered the most venomous scorpion in South America because of the high level of toxicity of its venom. It is responsible for causing serious accidents, mainly with kids. The species Bothrops jararaca is a serpent that has in its venom a complex mixture of enzyme, peptides and other molecules. The toxins of the venom of B. jararaca induce local and systemic inflammatory responses. The treatment chosen to serious cases of envenomation is the intravenous administration of the specific antivenom. However, the treatment is not always accessible to those residents in rural areas, so that they use medicinal plant extracts as the treatment. In this context, aqueous extracts, fractions and isolated compounds of Aspidosperma pyrifolium (pereiro) and Ipomoea asarifolia (salsa, salsa-brava), used in popular medicine, were studied in this research to evaluate the anti-inflammatory activity in the peritonitis models induced by carrageenan and peritonitis induced by the venom of the T. serrulatus (VTs), and in the local oedema model and inflammatory infiltrate induced by the venom of the B. jararaca, administrated intravenously. The results of the assays of cytotoxicity, using the MTT, showed that the aqueous extracts from the plant species presented low toxicity to the cells that came from the fibroblast of the mouse embryo (3T3).The chemical analysis of the extracts by High Performance Liquid Chromatography revealed the presence of the rutin flavonoid, in A. pyrifoliu, and rutin, clorogenic acid and caffeic acid, in I. asarifolia. Concerning the pharmacological evaluation, the results showed that the pre-treatment using aqueous extracts and fractions reduced the total leukocyte migration to the abdominal cavity in the peritonitis model caused by the carrageenan and in the peritonitis model induced by the T. serulatus venom. Yet, these groups presented anti-oedematous activity, in the local oedema model caused by the venom of the B. jararaca, and reduced the inflammatory infiltrate to the muscle. The serum (anti-arachnid and anti-bothropic) specific to each venom acted inhibiting the inflammatory action of the venoms and were used as control. The compounds identified in the extracts were also tested and, similar to the plant extracts, showed meaningful anti-inflammatory effects, in the tested doses. Thus, these results are indicating the potential anti-inflammatory activity of the plants studied. This is the first research that evaluated the possible biological effects of the A. pyrifolium and I. asarifolia, showing the biological potential that these species have.
Resumo:
Accidents caused by venomous animals represents a significant and serious public health problem in certain regions of Brazil, as well as in other parts of the world by the frequency with which they occur and the mortality they cause. The use of plant extracts as an antidote for poisoning cases is an ancient practice used in many communities that have no access to antivenom. Medicinal plants represent an important source of obtaining bioactive compounds able to assist directly in the treatment of poisoning or indirectly supplementing serum therapy currently used. The aim of this study was to evaluate the effect of extracts, fractions and isolated compounds from M. tenuiflora and H. speciosa in the inflammatory process induced by carrageenan and the venom of B. jararaca and T. serrulatus. The results showed that both M. tenuiflora and H. speciosa were capable of inhibiting cell migration and cytokines levels in peritonitis induced by carrageenin and venom of T. serrulatus. In poisoning by B. jararaca model, mice treated with the plants in studies decreased the leukocyte influx into the peritoneal cavity. Finally the M. tenuiflora and H. speciosa had antiphlogistic activity, reducing edema formation and exerted inhibitory action of leukocyte migration in local inflammation induced by the venom of B. jararaca. Through of Thin Layer Chromatography (TLC) analysis was possible identified the presence of flavonoids ,saponins and/or terpenes in aqueous extract of M. tenuiflora. By High Performance Liquid Chromatography analysis, it was possible to identify the presence of rutin and chlorogenic acid in aqueous extract of H. speciosa. We conclude that the administration of extracts, fractions and isolated compounds of H. speciosa and M. tenuiflora resulted in inhibition of the inflammatory process in different experimental models. This study demonstrates for the first time the effect of M. tenuiflora and H. speciosa in inhibition of the inflammation caused by B. jararaca and T. serrulatus venom.
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The aim of this study was to analyze the immunoexpression of calcitonin (CTR) and glucorticoid (GCR) receptors in aggressive and non-aggressive central giant cell lesions (CGCL). This is an immunohistochemistry study (immunoperoxidase technique) of 52 cases of CGCL of the jaws, in which 12 patients were treated with intralesional triamcinolone injections and one with calcitonin nasal spray. The mean of immunostaining was compared between the cell types and clinical subtype of the lesion. The correlations among means were analyzed by Mann-Whitney test. Of the 52 cases studied, 53.8% were females, with a mean of 25.69 years. Most lesions were located in the mandible. Thirty patients (57.7%) had aggressive lesions and 22 (42.3%) of the cases consisted of non-aggressive lesions. Surgery was the treatment of choice in 75% of the cases. In 56.7% of the aggressive CGCL surgery was performed, while 43.4% of patients were submitted to conservative treatment. Among cases submitted to conservative treatment, the majority (n = 8; 61.5%) responded well to treatment. CTR expression was observed in 67.3% and GCR in 96.15% of cases. There was no significant statistical difference between the expression of CTRs and GCRs in mononuclear and multinucleated CGCLscells, regarding aggressiveness, treatment performed for aggressive lesions and the response to conservative treatment (p>0.05). The results of our research suggest that the immunoreactivity of CTRs and GCRs did not influence the response to clinical treatment with calcitonin or triamcinolone in the sample studied and it exhibited a varied expression regardless of the aggressiveness of the lesion.
Resumo:
The aim of this study was to analyze the immunoexpression of calcitonin (CTR) and glucorticoid (GCR) receptors in aggressive and non-aggressive central giant cell lesions (CGCL). This is an immunohistochemistry study (immunoperoxidase technique) of 52 cases of CGCL of the jaws, in which 12 patients were treated with intralesional triamcinolone injections and one with calcitonin nasal spray. The mean of immunostaining was compared between the cell types and clinical subtype of the lesion. The correlations among means were analyzed by Mann-Whitney test. Of the 52 cases studied, 53.8% were females, with a mean of 25.69 years. Most lesions were located in the mandible. Thirty patients (57.7%) had aggressive lesions and 22 (42.3%) of the cases consisted of non-aggressive lesions. Surgery was the treatment of choice in 75% of the cases. In 56.7% of the aggressive CGCL surgery was performed, while 43.4% of patients were submitted to conservative treatment. Among cases submitted to conservative treatment, the majority (n = 8; 61.5%) responded well to treatment. CTR expression was observed in 67.3% and GCR in 96.15% of cases. There was no significant statistical difference between the expression of CTRs and GCRs in mononuclear and multinucleated CGCLscells, regarding aggressiveness, treatment performed for aggressive lesions and the response to conservative treatment (p>0.05). The results of our research suggest that the immunoreactivity of CTRs and GCRs did not influence the response to clinical treatment with calcitonin or triamcinolone in the sample studied and it exhibited a varied expression regardless of the aggressiveness of the lesion.
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Campbell Plateau occupies a key position in the southwest Pacific sector of the Southern Ocean. The plateau confines and steers the Antarctic Circumpolar Current (ACC) along its flanks, isolating the Subantarctic plateau from cold polar waters. Oxygen and carbon isotope records from Campbell Plateau cores provide new records of water mass stratification for the past 130 kyr. During glacial climes, strengthening of the Subantarctic Front (SAF) caused waters over the plateau flanks to be deeply mixed and ~3°C cooler. Waters of the plateau interior remained stratified and isolated from the cold southern waters. In the west, waters cooled markedly (~4°C) owing to reduced entrainment of Tasman Sea water. Marked cooling also occurred north of Campbell Plateau under increased entrainment of polar water by a branch of the SAF. The ACC remained along the flanks of Campbell Plateau during the last interglacial, when interior waters were stratified and warmer by ~1°C than now.
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This study makes an approach to the Morro Agudo Community (Cisterna) located in Catalão city(GO) rural area where stands the Maria Bárbara Sucena Municipal School. This school center is a result of getting together several small and isolated schools, which worked, scattered in many rural communities in the region. After this centralization in a single school, many students had to move along inconvenient distance to get their classes. Morro Agudo Community (Cisterna) was outstanding at garlic cultivation throughout the 1990`s when eventually this activity came to a decline. The region is constituted by properties of small tract of land. The landowners come from a Portuguese background and there are, in addit ion, migrant workers from the northeast region of Brazil. These northeasterners work for these local landowners, and that brings an additional meaning to the social relations in the region and to the rural schooling. The social and cultural diversity of the region has a feedback at the school arising tensions in many ways. In the teaching and learning process the school deals with this diversity, combined with rules and goals that, in the end, delivers a geography teaching not able to value the local knowledge accumulated in the region by its own inhabitants. New methodological approaches to rural school communities emerged out of the analysis of these unmet expectations. Furthermore, this study takes into consideration some “residues”, that means not all events are fit into programs; there are unintended consequences in an open process. All these are object of deep review in this doctoral dissertation. In this community, an analysis of the public policies implemented by Federal and municipal governments to rural schools communities in Brazil was conducted. The way in which public policies toward rural communities are implemented at the schools was reviewed; the goals they pursue and the role played by textbooks are also object of analysis. This study questions the relevance of this tools, mainly if they meet the real needs of the local people. The social representations of teachers and students are considered carefully based on their everyday lives and experiences.
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Several vertebrae of a sauropterygian specimen have been recovered in Fuencaliente de Medinaceli (Soria Province, Castilla y León, Spain). The remains come from Middle–Upper Triassic Muschelkalk Facies. This finding represents the first documented evidence of a Triassic tetrapod in Castilla y León. The vertebrae belong to Nothosaurus, a sauropterygian genus found in Europe, Middle East, North of Africa and China. This genus is poorly-known in the Iberian record. The new remains constitute the first evidence of the species Nothosaurus giganteus, or a related taxon, in the Iberian Peninsula. This study reveals the occurrence of at least two species of the sauropterygian Nothosaurus in the Spanish record.
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Angiotensin-converting enzyme (EC3.4.15. I; ACE), isa membrane-bounddipeptidyl carboxypeptidase that mediates the cleavage of the C-terminal dipeptide His-Leu of the decapeptide angiotensin, generating the most powerful endogenous vaso-constricting angiotensin.
Some ACE inhibitors, such as Captopril, have been used as anti-hypertensive drugs. Moreover in recent years, large quantities of ACE inhibitors have been identijied and isolated from peptides derivedfrom food material such as casein, soy protein, jish protein and so on. Functional food with hypotensive effect has been developed on the basis of these works.
Typicalprocedures for screening hypotensive peptides offood origins are separationof products of peptic and tryptic digestion of proteins followed by inhibitory activitydetermination of each fraction. A method developed by Cushman has been the mostwidely used, in which ACE activity is determined by the amount of hippuric acid
generated as a product of enzymatic reaction of ACE with tripeptide of hippuryl-Lhistidyl-L-leucine. Hippuric acid is determined spectrophotometrically at 228 nm after its isolation from the reaction system by ethylacetate extraction, which not only requires alarge quantity of reagent but also results in large error.
An improved method based on Cushman ’s method is proposed in this paper. In this method, an enzymatic reaction system is based on Cushman’s method, while isolation and determination of hippuric acid is performed by medium perjormance gel chromatography on a Toyopearl HW-40s column. Due to the size exclusion nature of the column with somewhat hydrophobic properties, complete separation of four existing fractions in the reaction system is obtained within a smallfraction of the time necessary in Cushman’s method, with ideal reproducibility.
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The inclusion of the dentist in the Family Health Program (FHP) teams designates a reorganization of the mouth health care in your country and establishes a new scenario in Brazilian odontology, through of a new way to organize the basic health care, creating conditions to consolidate in mouth health practice actions, in the level of the basic attention, the validation of Unique Health System (UHS) constitutional principles. The purpose of this research is to verify if the actuation of mouth health teams (MHT) dentists, in Natal city north sanitary district, is tuned with FHP goals.The target research population was composed by all dentists working in Basic Health Units (BHU) of Natal north sanitary district. Fifth-eight questionnaires were applied and using open and closed questions we look for identify the functional characteristics of each BHU, the dentists professional attributions on each BHU, as well as the clinical procedures that they execute. This research also searched to identify the factors that facilitate and/or difficult the inclusion process and the dentists activities performance on these BHUs, as well as the necessary actions to north sanitary district MHTs to fulfill the objectives proposed by FHP. The results point that the inclusion of mouth health actions in north sanitary district FHPs brought the incorporation of new values to the used practices. Whoever, its necessary a more frequent evaluation of the carried actions, in a way they can be adapted to the real community necessities, and, is fundamental the data accompaniment, for that these serve of base for planning and redirecting activities, in a way that we do not have only a reproduction of traditional practices, fragmented and isolated, but a truly substitution of the traditional practices and a new way of promoting health