Medição da densidade óssea através de ondas eletromagnéticas e classificação por MVS

This work holds the purpose of presenting an auxiliary way of bone density measurement through the attenuation of electromagnetic waves. In order to do so, an arrangement of two microstrip antennas with rectangular configuration has been used, operating in a frequency of 2,49 GHz, and fed by a microstrip line on a substrate of fiberglass with permissiveness of 4.4 and height of 0,9 cm. Simulations were done with silica, bone meal, silica and gypsum blocks samples to prove the variation on the attenuation level of different combinations. Because of their good reproduction of the human beings anomaly aspects, samples of bovine bone were used. They were subjected to weighing, measurement and microwave radiation. The samples had their masses altered after mischaracterization and the process was repeated. The obtained data were inserted in a neural network and its training was proceeded with the best results gathered by correct classification on 100% of the samples. It comes to the conclusion that through only one non-ionizing wave in the 2,49 GHz zone it is possible to evaluate the attenuation level in the bone tissue, and that with the appliance of neural network fed with obtained characteristics in the experiment it is possible to classify a sample as having low or high bone density

Adesão de células mesenquimais da medula óssea de camundongos e do ligamento periodontal de ratos a diferentes superfícies de titânio: estudo comparativo in vitro

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

Avaliação de alterações orais em pacientes submetidos a transplante de medula óssea

Bone marrow transplantation (BMT) is currently the best therapeutic option for patients with hematologic diseases, solid tumors or autoimmune disorders. It is characterized by intravenous infusion of hematopoietic stem cells in order to restore marrow function. However, this procedure requires concomitant immunosuppression treatment, which favors the development of certain complications, often manifested in the oral cavity. This study aimed to evaluate the incidence of oral changes in patients undergoing BMT and to correlate these results with clinical aspects related to the patients and the transplants performed. This is a prevalence study, with cross-sectional design, carried out in a BMT service at the Institute of Onco-Hematology of Natal (ION) and Natal Hospital Center. Data collection was based on questionnaires, clinical examination of the oral cavity and consultation in the medical records. The sample consisted of 51 patients undergoing BMT. After the analysis, was found a general status with good health conditions and presence of oral changes in about half of patients who composed the sample. The manifestations observed were, in decreasing order of frequency: mucositis; gingival alteration and thrombocytopenic purpura; mucosal pigmentation; lichenoid reaction and candidiasis. The oral changes were observed more frequently in cases of allogeneic TMO, in different periods post-transplant, without significant differences related to the source of cells. It was found statistically significant association between the presence of graft-versus-host disease (GVHD) and oral changes (p < 0,001). Therefore, it is concluded that there is a relatively high incidence of changes in oral cavity of patients receiving bone marrow transplantation, a fact which confirms the need to consider this site for examination, diagnosis, treatment and prognosis of possible complications of BMT

Exprassão imuno-histoquímica dos fatores de reabsorção óssea em lesões centrais e periféricas de células gigantes

The Giant Cell Lesions, both the Central Giant Cells Lesions (CGCL) as the Peripheral Giant Cells Lesions (PGCL), correspond to a group of oral lesions that are histologically similar entities; however they show a variable clinical behaviour. The purpose of this study was to compare the immunohistochemical expression of bone resorption factors RANK (Receptor Activator of Nuclear Factor kappa B), RANKL (Receptor Activator of Nuclear Factor kappa B Ligand) and OPG (Osteoprotegerin) between CGCL and PGCL. Additionally, these bone resorption factors were examined in terms of aggressiveness of these lesions. The sample consisted of 61 cases, 30 cases of PGCL and 31 CGCL (16 non-aggressive and 15 aggressive). The analysis was performed by quantification of mononuclear cells (MO) and giant multinucleated cells (CG) immunopositive to anti-RANK, anti-RANKL and anti-OPG antibodies in 10 fields. Moreover, according to the proportion between the amount of cells positive for RANKL and OPG, the cases were categorized into: RANKL>OPG, OPG>RANKL e RANKL=OPG. CGCL showed a higher amount of MO (p=0.002) and total cells (p=0.003) both positives to RANKL compared with the PGCL. Additionally, the CGCL revealed a significant association with the ratio of RANKL>OPG (p=0.001). Analysis of the bone resorption factors revealed no significant differences between aggressive and non-aggressive CGCL (p>0.05). It was observed a positive correlation between the markers themselves, and a negative correlation between lesion size and quantity of OPG positive MO cells (p=0,004) and total cells (p=0,009). Through these results, we suggest that the greatest CGCL resorptive potential compared to the PGCL, may have occurred to the high expression of RANKL. Furthermore differences in the biological behavior of aggressive and non-aggressive CGCL appear to be related to the expression of these bone resorption factors

Expressão imuno-histoquimica de proteínas relacionadas com a reabsorção óssea em carcinoma epidermoide de palato duro e língua

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Plasticidade de células tronco mesenquimais de medula óssea de ratos na presença de meio condicionado do nervo facial e do fator de crescimento fibroblástico 2

A number of evidences show the influence of the growth of injured nerve fibers in Peripheral Nervous System (PNS) as well as potential implant stem cells (SCs) to make it more suitable for nerve regeneration medium. In this perspective, this study aimed to evaluate the plasticity of mesenchymal stem cells from bone marrow of mice in the presence of culture medium conditioned with facial nerve explants (D-10) and fibroblast growth factor-2 (FGF-2). In this perspective, the cells were cultivated only with DMEM (group 1), only with D-10(group 2), only with FGF-2(group 3) or with D-10 and FGF-2(group 4). The growth and morphology were assessed over 72 hours. Quantitative phenotypic analysis was taken from the immunocytochemistry for GFAP, OX-42, MAP-2, β-tubulin III, NeuN and NF-200 on the fourth day of cultivation. Cells cultured with conditioned medium alone or combined with FGF-2 showed distinct morphological features similar apparent at certain times with neurons and glial cells and a significant proliferative activity in groups 2 and 4 throughout the days. Cells cultived only with conditioned medium acquired a glial phenotype. Cells cultured with FGF-2 and conditioned medium expressed GFAP, OX-42, MAP-2, β-tubulin III, NeuN and NF-200. On average, area and perimeter fo the group of cells positive for GFAP and the área of the cells immunostained for OX-42 were higher than those of the group 4. This study enabled the plasticity of mesenchymal cells (MCs) in neuronal and glial nineage and opened prospects for the search with cell therapy and transdifferentiation

Influência do tamoxifeno associado ao diabete melito na densidade mineral óssea

Considering that osteopenia and osteoporosis are diabetes mellitus complications, and that tamoxifen (TAM) is an anti-estrogenic drug used in breast cancer treatment, this drug may have a beneficial action preventing accentuaded bone loss associated to diabetes. Female Wistar rats (n=60) weighting 180-250g were divided in four groups: Group C, control animals (n=5); Group T, animals treated with TAM (n=5); Group D, diabetic animals (n=5); and Group DT, diabetic animals treated with TAM (n=5). Oestrus cycle was evaluated before the beggining of experimental period to select the animals with regular cycle. This evaluation continued throughout the study period and for all studied groups. Diabetes was induced by a intra perithoneal injection of streptozotocin (STZ) in a concentration of 45 mg/Kg of body weight. Those animals with serum glicose levels 250 mg/dL were considered diabetics. Animals were sacrificed in the periods of 30, 60 and 90 days after diabetes onset. Left femur histomorphometric measurements and serum biochemical analysis (glycemia, alkaline phosphatase, tartaric-resistant acid phosphatase, calcium, phosphorous, magnesium, total proteins, albumin, globulins, urea and creatinine) were done. Histomorphometric results showed a progressive bone loss in Group D animals when compared to those from Group C all over the experimental period, becoming accentuaded in the 90 days period. In relation to Groups T and DT, values approcimated to those obtained for control group were found during the whole period of study. Those data may indicate a bone mass recovery or a diminished bone loss due to diabetes when animals were treated with TAM. During the whole experimental period animals of groups D and DT maintained glycemic levels above 250 mg/dL whereas animals of groups C and T maintained those levels below 150mg/dL. Alkaline phosphatase activity was increased in all study periods for groups D and DT when compared to group C animals over the 90 days period. Tartarate-resistant acid phosphatase activity was showed unaltered in all periods of study and for all groups. Calcium and magnesium results were also unaltered, maintaining reference levels for all groups in all experimental periods. Phosphorous levels were increased in groups D and DT when compared to groups C and T in the 30 days period. However no difference was found in the periods of 60 and 90 days for this test. No difference was found for total proteins levels for groups C, T, D and DT over the study period. Albumin levels were reduced in DT group in the 60 days period and in D and DT groups in the 90 days period. Urea levels were significantly increased in the 30, 60 and 90 days study periods in groups D and DT when compared to groups C and T. Creatinine results showed a significantly increase in the 90 days period for groups D and DT when compared to groups C and T, and maintaining unaltered in the 30 and 60 days periods. These results suggest that the treatment with TAM may reduce bone loss caused by diabetes mellitus