998 resultados para Células - tronco
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O presente estudo teve como objetivo avaliar o rendimento da espermatogênese de cutias criadas em cativeiro, por intermédio das razões encontradas entre tipos celulares do epitélio seminífero. Os resultados apontaram que o rendimento da espermatogênese da cutia dos nove aos quatorze meses de idade não chegou a um ponto de estabilização. O coeficiente de eficiência de mitoses espermatogoniais não aumentou com a idade. O rendimento meiótico, o rendimento geral da espermatogênese e o índice de células de Sertoli mostraram variações numéricas em função da idade, entretanto, não detectadas estatisticamente.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Visando estudar as associações genéticas e fenotípicas entre a contagem de células somáticas (CCS) e a produção de leite até 305 dias (P305) e avaliar as perspectivas de utilização da CCS como critério de seleção em bovinos leiteiros, utilizaram-se dados obtidos pelo Programa de Análise da Eficiência de Rebanhos Leiteiros e da Qualidade do Leite, desenvolvido pelo Laboratório de Qualidade do Leite da ESALQ - USP. Por não apresentar distribuição normal, a contagem de células somáticas (CCS) foi transformada para uma escala logarítmica (ECS). Foram estimados os parâmetros genéticos para a P305 dias e a média dos escores de células somáticas (MECS). A média da produção de leite até 305 dias foi de 7.519,51 kg e a da MECS, de 4,04. As herdabilidades estimadas para P305 e MECS foram de 0,22 e 0,13, respectivamente, nas análises univariadas. Valores semelhantes foram estimados pela análise bivariada. A correlação genética entre a P305 e MECS foi de -0,16. Por apresentar correlação genética negativa, mas de baixa magnitude, a seleção para produção de leite não ocasionaria, a princípio, aumento indesejável da MECS.
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The conversion of solar energy in electric with photo-voltaic cells has been carried through exclusively with devices of semiconducting junction. To put this situation comes moving for better in them last years, thanks to a new technology of production of known solar cells as Dye Solar Cell. This proposal aims at to develop a DSC having as dye lavonoides of the Capsicum frutescens (malagueta pepper). Front is considered to evaluate the photo-voltaic parameters varies it regions of the visible specter, as well as a good efficiency of conversion
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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To the vertebrates, maintain body balance against the gravitational field and be able to orient themselves in the environment are fundamental aspects for survival, in which the participation of vestibular system is essential. As part of this system, the vestibular nuclear complex is the first central station that, by integrating many information (visual, proprioceptive), and the vestibular, assumes the lead role in maintaining balance. In this study, the vestibular nuclear complex was evaluated in relation to its cytoarchitecture and neurochemical content of cells and axon terminals, through the techniques of Nissl staining and immunohistochemistry for neuronal specific nuclear protein (NeuN), glutamate (Glu), substance P (SP), choline acetyltransferase (ChAT) (enzyme that synthesizes acetylcholine-Ach) and glutamic acid decarboxylase (GAD) (enzyme that synthesizes gamma-amino butyric acid-GABA). The common marmoset (Callithrix jacchus) was used as experimental animal, which is a small primate native from the Atlantic Forest in the Brazilian Northeast. As results, the Nissl technique, complemented by immunohistochemistry for NeuN allowed to delineate the vestibular nucleus superior, lateral, medial and inferior (or descending) in the brain of the common marmoset. Neurons and terminals immunoreactive to Glu and ChAT and only immunoreactive terminals to SP and GAD were seen in all nuclei, although in varying density. This study confirms the presence in the vestibular nuclei of the common marmoset, of Glu and SP in terminals, probably from the first order neurons of vestibular ganglion, and of GABA in terminals, presumably from Purkinge cells of the cerebellum. Second-order neurons of the vestibular nuclei seem to use Glu and Ach as neurotransmitters, judging by their expressive presence in the cell bodies of these nuclei in common marmosets, as reported in other species
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The present experiment used cell culture to analyze the adhesion capacity of mouse mesenchymal bone marrow cells and rat periodontal ligament to different titanium surfaces. Grade II ASTM F86 titanium discs 15mm in diameter and 1.5mm thick were used and received 2 distinct surface treatments (polished and cathodic cage plasma nitriding). The cells were isolated from the mouse bone marrow and rat periodontal ligament and cultured in α-MEM basic culture medium containing antibiotics and supplemented with 10% FBS and 5% CO2, for 72 hours at 37ºC in a humidified atmosphere. Subculture cells were cultured in a 24-well plate with a density of 1 x 104 cells per well. The titanium discs were distributed in accordance with the groups, including positive controls without titanium discs. After a 24-hour culture, the cells were counted in a Neubauer chamber. The results show that both the mouse mesenchymal bone marrow cells and rat periodontal ligament cells had better adhesion to the control surface. The number of bone marrow cells adhered to the polished Ti surface was not statistically significant when compared to the same type of cell adhered to the Ti surface treated by cathodic cage plasma nitriding. However a significant difference was found between the control and polished Ti groups. In relation to periodontal ligament cell adhesion, a significant difference was only found between the control and plasma-treated Ti surfaces. When comparing equal surfaces with different cells, no statistically significant difference was observed. We can therefore conclude that titanium is a good material for mesenchymal cell adhesion and that different material surface treatments can influence this process
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Cryopreservation is a process where cells or biological tissues are preserved by freezing at very low temperatures and aims to cease reversibly, in a controlled manner, all the biological functions of living tissues, i.e., maintain cell preservation so that it can recover with high degree of viability and functional integrity. This study aimed to evaluate the influence of cryopreservation on the mesenchymal stem cells originating from the periodontal ligament of human third molars by in vitro experiments. Six healthy teeth were removed and the periodontal cells grown in culture medium containing α-MEM supplemented with antibiotics and 15% FBS in a humidified atmosphere with 5% CO2 at 37° C. Cells isolated from each sample were divided into two groups: Group I - immediate cell culture (not fresh cryopreserved cells) and Group II - cell cryopreservation, during a period of 30 days. Analyses of rates of cell adhesion and proliferation in different groups were performed by counting the cells adhered to the wells, in intervals of 24, 48 and 72 hours after the start of cultivation. The number of cells in each well was obtained by counting viable cells with the use of hemocytometer and the method of exclusion of cells stained by trypan blue. The difference between groups for each of the times was analyzed by Wilcoxon test. Regarding the temporal evolution for each group, analysis was done by Friedman's test to verify the existence of differences between times and, when it existed, the Wilcoxon penalty was applied. The results showed no statistically significant difference between the two groups analyzed in this study. Therefore, we conclude that the cryopreservation process, after a period of 30 days, did not influence the cell type studied, and there was no difference in growth capacity in vitro between the groups
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The oral manifestations due to HIV infection are, a lot of times, the first clinical signs of the disease. These injuries may also function as beepers and sentries of the curse and progression of the HIV infection and AIDS. The objective of this work was to evaluate the prevalence of the oral injuries in HIV positive patients, relating them with the CD4+ cells counting and the viral load in patients from the Hospital of Infected contagious Gizelda Trigueiro in Natal-RN. One hundred and one patients were evaluated, where after the clinical exam of the oral cavity, these ones were conducted to the peripheral blood collection for the counting of CD4+ lymphocytes. We observed a prevalence of 25,6%, that is, 31 cases. The Oral Candidiasis was the most commum injure, followed by Oral Hairy Leukoplakia, linear gingival erytema, lips herpes, gingivitis and periodontitis - HIV. The average counting of cells CD4+ of the injury carrying patients was of 250 cells/mm3. We did not observe relation between the presence of injuries and the viral load of the individuals
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The giant cell fibroma is a benign neoplasm characterized by the presence of mono, bi or multinucleate cells, which can have a connection to the presence of mast cells. This research aims to analyze, descriptively and comparatively, the immunohystochemistry expression of the tryptase in mast cells of the giant cell f ibroma, f ibrous hyperplasia and samples of the normal oral mucosa. Thirty cases of giant cell fibroma, ten cases of fibrous hyperplasia and ten cases of normal oral mucosa were selected for the analysis of the immunohistochemistry expression, determination of the number of present mast cells, as well as their location and shape. It could be stated that there was a statistically signif icant difference (p<0,001) in relation to the quantity of mast cells among other samples analyzed where the giant cell f ibroma presented lesser quantity of mast cell and the hyperplasia showed higher concentration of this cellular type. Although the oral mucosa has presented a higher quantity of mast cells when compared to the giant cells fibroma, these were found in usual locations in the connective tissue in normal tissues. There could be noticed a statistically significant difference in relation to the number of non-granulated mast cells (p<0,001). On the areas of fibrosis, we could observe a statistically signif icant difference (p<0,006) among the samples. In relation to the present mast cells in perivascular location, no statistically signif icant difference was found. On the morphological analysis there was a predominance of oval mast cells. It was concluded that despite of the fact there was a lesser quantity of mast cells present in cases of giant cell f ibroma, they appeared to have a stronger relation to the present giant fibroblasts in this lesions, around 59,62%, being also evidenced a strong relation between these cells and the fibrosis areas in both cases of giant cell f ibroma and f ibrous hyperplasias and samples of normal oral mucosa, used as control group in our study, confirming, this way, the role of the mast cells as fibrinogenous inductor
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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.