4 resultados para heat shock protein 90
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
Control of human visceral leishmaniasis in endemic regions is hampered in part by the lack of knowledge with respect of the role reservoirs and vector. In addition, there is not yet an understanding of how non-symptomatic subclinical infection might influence the maintenance of infection in a particular locality. Of worrisome is the limited accessibility to medical care in places with emerging drug resistance. There is still no available protective vaccine either for humans or other reservoirs. Leishmania species are protozoa that express multiple antigens which are recognized by the vertebrate immune system. Since there is not one immunodominant epitope recognized by most hosts, strategies must be developed to optimize selection of antigens for prevention and immunodiagnosis. For this reason, we generated a cDNA library from the intracellular amastigote form of Leishmania chagasi, the causative agent of South American visceral leishmaniasis. We employed a two-step expression screen of the library to systematically identify T and T-dependent B cell antigens. The first step was aimed at identifying the largest possible number of clones producing an epitope-containing polypeptide with a pool of sera from Brazilians with documented visceral leishmaniasis. After removal of clones encoding heat shock proteins, positive clones underwent a second step screen for their ability to cause proliferation and IFN-γ responses of T cells from immune mice. Six unique clones were selected from the second screen for further analysis. The clones encoded part of the coding sequence of glutamine synthetase, transitional endoplasmic reticulum ATPase, elongation factor 1γ, kinesin K-39, repetitive protein A2, and a hypothetical conserved protein. Humans naturally infected with L. chagasi mounted both cellular and antibody responses to these protein Preparations containing multiple antigens may be optimal for immunodiagnosis and protective vaccines against Leishmania
Resumo:
Squamous cell carcinoma of oral tongue shows high rates of morbidity and mortality in the population, therefore, great efforts are being made to classify morphological changes and identify biomarkers that have prognostic value and that are able to group patients in individualized therapeutic options. From this perspective, there is the heat shock factor 1 (HSF1), which is a heat shock factor transcription protein (HSPs) that allows the cancer to deal with stressors associated with malignancy, acting differently in tumor progression. This research aimed to perform a clinico-pathological analysis of 70 cases of oral tongue squamous cell carcinoma (OTSCC) and immunohistochemical study of the expression of HSF1 protein in OTSCC, comparing it with 30 specimens of normal oral mucosa (NOM), and correlating this immunostaining with clinico-pathological aspects of OTSCC. To analyze the association between immunoexpression of HSF1 and clinicophatoloical aspects, the cases were categorized in minor and major overexpression, based in the median immunostaining score. Regarding the cases of OTSCC, 57.1% showed clinical stage III or IV, 82.9% were graded as high grade according to Bryne (1998) and 47.1% as high risk of malignancy according to Brandwein-Gensler et al., (2005). A disease free survival rate of 47.84% and overall survival rate of 68.20% was observed in the analyzed cases, and the high degree of malignancy according to Bryne’s system (1998) (p=0.05), tumor size T3 or T4 (p=0.04), local recurrence (p=0.02), and perineural invasion (p=0.02) determined negative impacts in survival time. We observed also a statistically significant result (p<0.01) when comparing the immunoreactivity of HSF1 between NOM and OTSCC. This significantly increased expression of HSF1 in cases of OTSCC suggests that this protein acts, indeed, in the pathogenesis of this disease. However, there were no statistically significant associations between this overexpression and the clinico-pathological parameters analyzed. This finding may reflect the influence of epigenetic events on HSF1 gene or a possible stability of this protein expression throughout disease progression.
Resumo:
Squamous cell carcinoma of oral tongue shows high rates of morbidity and mortality in the population, therefore, great efforts are being made to classify morphological changes and identify biomarkers that have prognostic value and that are able to group patients in individualized therapeutic options. From this perspective, there is the heat shock factor 1 (HSF1), which is a heat shock factor transcription protein (HSPs) that allows the cancer to deal with stressors associated with malignancy, acting differently in tumor progression. This research aimed to perform a clinico-pathological analysis of 70 cases of oral tongue squamous cell carcinoma (OTSCC) and immunohistochemical study of the expression of HSF1 protein in OTSCC, comparing it with 30 specimens of normal oral mucosa (NOM), and correlating this immunostaining with clinico-pathological aspects of OTSCC. To analyze the association between immunoexpression of HSF1 and clinicophatoloical aspects, the cases were categorized in minor and major overexpression, based in the median immunostaining score. Regarding the cases of OTSCC, 57.1% showed clinical stage III or IV, 82.9% were graded as high grade according to Bryne (1998) and 47.1% as high risk of malignancy according to Brandwein-Gensler et al., (2005). A disease free survival rate of 47.84% and overall survival rate of 68.20% was observed in the analyzed cases, and the high degree of malignancy according to Bryne’s system (1998) (p=0.05), tumor size T3 or T4 (p=0.04), local recurrence (p=0.02), and perineural invasion (p=0.02) determined negative impacts in survival time. We observed also a statistically significant result (p<0.01) when comparing the immunoreactivity of HSF1 between NOM and OTSCC. This significantly increased expression of HSF1 in cases of OTSCC suggests that this protein acts, indeed, in the pathogenesis of this disease. However, there were no statistically significant associations between this overexpression and the clinico-pathological parameters analyzed. This finding may reflect the influence of epigenetic events on HSF1 gene or a possible stability of this protein expression throughout disease progression.
Resumo:
The green bean has organoleptic and nutritional characteristics that make it an important food source in tropical regions such as the Northeast of Brazil. It is a cheap source of protein and important for nutrition of rural population contributing significantly in subsistence farming of the families from Brazil s northeast. It is consumed in entire region and together with the dry meat and other products composes the menu of typical restaurants, being characterized as an important product for economy of Northeast. The green bean is consumed freshly harvested and has short cycle, being characterized as a very perishable food, which hampers your market. The drying method is an alternative to increase the lifetime and provide a reduction volume of this product making easier your transportation and storage. However is necessary to search ways of drying which keep the product quality not only from the nutritional standpoint but also organoleptic. Some characteristics may change with the drying process such as the coloring, the rehydration capacity and the grains cooking time. The decrease of drying time or of exposure of the grains to high temperature minimizes the effects related with the product quality loss. Among the techniques used to reduce the drying time and improve some characteristics of the product, stands out the osmotic dehydration, widely used in combined processes such as the pretreatment in drying food. Currently the use of the microwaves has been considered an alternative for drying food. The microwave energy generates heat inside of materials processed and the heating is practically instantaneous, resulting in shorter processing times and product quality higher to that obtained by conventional methods. Considering the importance of the green beans for the Northeast region, the wastefulness of production due to seasonality of the crop and your high perishability, the proposal of this thesis is the study of drying grain by microwaves with and without osmotic pretreatment, focusing on the search of conditions of processes which favor the rehydration of the product preserving your organoleptic characteristics. Based on the analysis of the results of osmotic dehydration and dielectric properties was defined the operating condition to be used in pretreatment of the green bean, with osmotic concentration in saline solution containing 12,5% of sodium chloride, at 40°C for 20 minutes. The drying of green bean by microwave was performed with and without osmotic pretreatment on the optimized condition. The osmotic predehydration favored the additional drying, reducing the process time. The rehydration of dehydrated green bean with and without osmotic pretreatment was accomplished in different temperature conditions and immersion time according to a factorial design 22, with 3 repetitions at the central point. According to results the better condition was obtained with the osmotically pretreated bean and rehydrated at a temperature of 60°C for 90 minutes. Sensory analysis was performed comparing the sample of the green bean in natura and rehydrated in optimized conditions, with and without osmotic pretreatment. All samples showed a good acceptance rate regarding the analyzed attributes (appearance, texture, color, odor and taste), with all values above 70%. Is possible conclude that the drying of green bean by microwave with osmotic pretreatment is feasible both in respect to technical aspects and rehydration rates and sensory quality of the product
