5 resultados para GUMS

em Universidade Federal do Rio Grande do Norte(UFRN)


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The chemical nature of the hidrocarbons found in gasoline directly affects the formation of oxidation complexes known as gums. Such complexes are slightly soluble in gasoline and their formation is delayed with the use of inhibitors, known as antioxidants. In this study, a synthetic compound (βnaphtol) and a natural subproduct (hydrogenated cardanol, derived from cashewnut shell liquid CNSL) have been used in order to generate novel antioxidant substances. These compounds were submitted to chemical reactions including alkylation, nitration and reduction, with the purpose of forming the following derivatives: 6(Nethyl,Nethylamino)βnaphtol (AO1); 6(Nethyl,Ndiethylamino)βnaphtol (AO2); aminoβnaphtol (AO3); 2(Nethyl,Nethylamino)pentadecylphenol (AOC1), 2(Nethyl,Ndiethylamino)pentadecylphenol (AOC2) and aminopentadecylphenol (AOC3). The derivatives were subjected to accelerated oxidative stability assays (Potential Gum and Induction Period) and to storage assays (Washed Gum and ASTM Color) during six months, with naphtha provided by the petroleum refinery RPBC (Refinaria Presidente Bernardes de Cubatão, in Brazil). The results for the derivatives were compared to those for commercial additives [DBPC (2,6ditbutyl4methylpcresol) and PDA (N,N disecbutylpphenylenediamine)], which were also added to the naphtha produced at RPBC at the moment of sampling. From all tested antioxidants, the novel antioxidant AOC1 (derived from hydrogenated cardanol) yielded a better global performance. During the period of time in which the naphtha was stored, an examination of this material was carried out in parallel, using the mass spectrometry technique. This study allowed to monitor the formation of a triolefinic compound, as well as the observation of subsequent formation and rupture of the olefinic constituents. As an eventual result from these experimental investigations, a reaction route leading to gum formation has been suggested

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The assessment of oral health status in elderly patients is essential for the development of specific health policies. The prevalence of oral diseases is high in this population. The self-perception of oral health conditions influences the demand for oral care and quality of life for seniors. The aim of this study was to assess self-perception of oral health status in 100 elderly of both sexes, aged 60 years or older and functionally independent the Basic Health Unit of Felipe Camarão II, Natal, Brazil. For comparison of self-perception data was collected in Bom Pastor, Natal / RN. In this research data were collected a questionnaire grouped into two parts. The first part with the socio-demographic data, subjective and objective condition of oral health and access to the service, the second part GOHAI Index. This index consists of 12 items that make it possible to obtain information involving aspects of chewing, speech, phonation, and self-assessed oral health. The results were subjected to statistical tests of Mann-Whitney and Kruskal-Wallis test (α = 0.05), to identify possible predictors of self-evaluation. As a result, 69% were female, ages ranged from 60 to 86 years, with a median of 65 years. In relation to marital status 48% were married. For the years of study, the sample had an average of 3 years. For the last visit to the dentist, only 27% of seniors had visited the Dentist for less than a year. Regarding the questions about the presence of gingival and dental problems were answered by 46% and 21% respectively. The data on the perception of your teeth and gums, 44%. The index showed GOHAI value for self-perception of 30 points to Felipe Camarão and 28 points for the Bom Pastor, both considered a low perception. We identified predictors of self-rated number of people in the room, participate in any associational activity, there is problems with your teeth and your gums. Concluded a negative self-perception of oral health condition by Gone in both areas, influenced by socioeconomic and cultural issues, although they realize the importance given to oral health, but by the misfortunes of other prominent favored little valuing of oral health

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Oral Lichen Planus (OLP) is a relatively common, cronic inflammatory disease. Its etiopathogenesis is no completely understood and several factors have proposed in attempt to explain the appearance, variety of clinical manifestations and periods of exacerbation and remission of the symptons of the lesions. The objective of the present study was to assess the presence of local factors, systemic diseases and levels of anxiety in patients with OLP, investigating their association with the clinical characteristics of the lesions. The sample consisted of 37 patients with histopathologically confirmed OLP that were submitted to a clinical exam to evaluate the presence of smoking habits, consumption of alcoholic beverages, diabetes mellitus, hypertension and hepatitis C virus (HCV) infection. The existence of skin lesions, as well as the time course, clinical form, symptomatology, number and location of the oral lesions were also registered. The trait anxiety was measured by Spielberger s Stai-Trait Anxiety Inventory (STAI), and to associate the variables we used the chi-square or Fisher s exact test. It was observed that females were the most affected (75%) and the mean age of the patients was 53,3 years. Most cases were non-smoker (97,3%) and none was drinker. Diabetes mellitus and hypertension were present in 10,8% e 16,2% of the sample, respectively and only one patient was HCV-seropositive (2,7%). Moderate levels of anxiety were seen in most cases (78,4%) and 21,6% had elevated levels. The oral lesions persisted in 95% of the cases for a period of 6 months to 13 years. The erosive form was the most prevalent (57,1%) and symptons were reported by 45,7% of the patients. Multiple lesions were frequent (60%), affecting mainly the buccal mucosa, followed by gums e tongue. There was no significant association of the presence of diabetes mellitus, hypertension and levels of anxiety with the clinical form or symptomatology of the oral lesions (p>0,005), despite a trend in patients with hypertension to have erosive lesions. It was concluded that, in the sample studied, moderate levels of anxiety were commonly observed, and the HCV infection apparently is not related to the onset of the OLP. In this study, the presence of diabetes mellitus, hypertension and levels of anxiety seem not to be associated with the clinical characteristics of the lesions of OLP

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Periodontal disease is an infection initiated by oral periodontal pathogens that trigger an immune response culminating in tissue destruction. This destruction is mediated by the host by inducing the production and activation of lytic enzymes, cytokines and the stimulation of osteoclastogenesis. The aim of this study was to compare the immunohistochemical expression of factors involved in bone resorption, RANKL (Ligand Receptor Activator of Nuclear Factor kappa B), OPG (Osteoprotegerin) and TNF-α (tumor necrosis factor alpha) between the gingival healthy, gingivitis and chronic periodontitis and correlate them with clinical parameters. The sample consisted of 83 cases and 12 clinically healthy gums, 42 gingivitis and 29 periodontitis, from 74 adolescent and adult patients with a mean age of 35 years, without systemic changes and non-smokers, predominantly female and race brown. There was no statistically significant difference for the expression of anti-RANKL (p = 0.581) and RANKL / OPG ratio (p = 0.334) when comparing the three conditions, but the anti-OPG and anti-TNF-α showed statistically significant between the types of injury (p = 0.001 and p <0.001, respectively), showing greatest expression in periodontitis. In cases of periodontitis, the variable clinical attachment loss (PIC) was statistically significant and positive correlation, respectively, with immunostaining of anti-RANKL (p = 0.002, p = 0.001 and r = 0.642), anti-OPG (p = 0.018, p = 0.014 and r = 0.451), anti-TNF-α (p = 0.032, p = 0.014 and r = 0.453) and the percentage ratio of RANKL / OPG (p = 0.018, p = 0.002 and r = 0.544). The tooth mobility (MB) showed a statistically significant difference only with immunohistochemical anti-RANKL (p = 0.026), and probing depth (PD) was positively correlated with anti-RANKL (p = 0.028 and r = 0.409), both in cases of periodontitis. Only in cases of gingivitis TNF-α was positively correlated with RANKL (p = 0.012 and r = 0.384) and the RANKL / OPG ratio (p = 0.027 and r = 0.341). Given these results, we conclude that the greatest expression of TNF-α in periodontitis demonstrates a relationship with the progression and severity of periodontal disease and the correlation between all antibodies and clinical attachment loss demonstrates their involvement in periodontal bone resorption

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The aim of this study was determine whether an association exists in the gum tissue between the expression of markers of tissue hypoxia (HIF-1α and GLUT-1) with a marker of inflammatory activity (COX-2) and a marker of collagen degradation (EMMPRIN). Was performed immunohistochemistry with antibodies specific for these markers on 60 samples of gingival tissue divided into two groups: gums (n = 26) and gingivitis (n = 34) and expression was analyzed in the epithelial tissue and connective tissue . The reactivity epithelial for COX-2 was observed in only two cases as the HIF-1α, GLUT-1 and EMMPRIN was strongly expressed in the epithelial basal layer and the immunostaining was gradually decreased as the cells away from this layer, and negative in the region suprabasal in most specimens. In connective tissue, and HIF-1α EMMPRIN were strongly positive for most cases analyzed as GLUT-1 was negative in most cases. Immunostaining for COX-2 showed an association with gingival inflammatory infiltrate. The expression of EMMPRIN, HIF-1α and GLUT-1 in normal gums confirms the physiological role of these markers, however there was no association with tissue inflammation. Given the findings we can conclude that the inflammatory changes installed in frames of chronic gingivitis may not be sufficient to activate the factors of hypoxia to levels that can be quantified by immunohistochemical analysis, in addition, the findings are not conclusive in relationship to involvement of EMMPRIN in the secretion of MMPs to degrade collagen in the frames of gingivitis. We suggest the use of technical analysis and quantification of RNA of EMMPRIN and MMPs in order to determine whether collagen degradation observed in gingivitis suffers or not, significant influence of EMMPRIN for secretion and activation of MMPs