61 resultados para Células de medula óssea
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Th17 cells have been strongly associated to the pathogenesis of inflammatory and autoimmune diseases, although their influence on the carcinogenesis is still little known, there are reports of anti-tumor and protumoral actions. The objective of this study is to research the presence of Th17 lineage in lip and tongue SCC, using the analysis of the immunoexpression of IL-17 and RORγt, relating this immunoexpression with clinical and morphological findings in the attempt to better comprehend the role of these cells on the tumoral immunity of OSCCs. The results were submitted to non-parametric statistical tests with significance level of 5%. On the histomorphological analysis, it was observed the predominance of low level lesions on lip and high level lesions on tongue (p=0,024). It was not observed statistical significance between clinical stage and histological gradation of malignancy (p=0,644). For the immunohistochemical study, 5 random fields with greater immunoreactivity of the peritumoral inflammatory infiltrate were photomicrographed on the 400x magnification. It was done the count of lymphocytes which showed cytoplasmic and pericytoplasmic staining for the IL-17 cytokine as well as nuclear and cytoplasmic staining for RORγt. It was observed statistical significance difference on the quantity of immunopositive lymphocytes to IL-17 between the groups of SCC of lip and tongue (p=0,028). For the RORγt it was not observed statistical significance difference between the groups of SCC of lip and tongue (p=0,915). It was not observed statistical difference between the immunostaining of IL-17 and RORγt with histological gradation of malignancy and clinical staging. The findings of this research suggest a possible anti-tumor role of IL-17 for cases of lip. The results of the analysis of the RORγt are possibly due to the wide duality of the anti-tumor and protumoral role of the Th17 cells and their plasticity which, in the presence of different cytokines expressed on the tumor microenvironment, can alter its phenotype.
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Ameloblastomas and keratocystic odontogenic tumors (KOT) represent odontogenic lesions that, despite their benign nature, are distinguished by a distinct biological behavior, characterized by locally aggressive growth and recurrent episodes. The gnathic bone resorption caused by the growth of these lesions is a key to the expansion of the same, both being mediated by osteoclastic cells like enzymatic activity of various matrix metalloproteinases (MMPs) factor. The expression of stimulatory factors and inhibitors of bone resorption has been correlated with the development of these lesions, with emphasis to some MMPs such as collagenases and gelatinases and tissue inhibitors of metalloproteinases (TIMPs), among others. Based on the premise that stimulatory and inhibitory factors of osteolytic processes can be decisive for the growth rate of intraosseous odontogenic lesions, this experiment evaluated the immunoreactivity of MMP-9, -13 and TIMP-1 protein in the epithelium and mesenchyme of ameloblastoma and the KOT specimens, by a quantitative analysis of the immunoreactivity cells. Statistical analysis was performed using the Mann-Whitney and Wilcoxon tests with a significance level set at 5 %. Immunohistochemical expression of MMP-9, -13 and TIMP-1 was observed in 100% of cases both in the epithelium and in mesenchyme. The immunoreactivity in the epithelium of KOT and ameloblastomas revealed a predominance of score 3 for MMP-9 (p=0.382) and MMP-13 (p=0.069) and no statistically significance for TIMP-1, the latter being significantly higher immunoreactivity in ameloblastomas. In the mesenchyme, there was a higher score immunoreactivity of MMP-13 (p=0.031) in ameloblastomas in relation to KOT, whereas for MMP-9 and TIMP-1 no statistically significant difference (p=0.403 was observed, p=1.000). The calculation of the ratio of scores revealed expression of proteins in general, similarity of the lesions, a significant predominance of equal expression of TIMP-1 and MMP-9 was observed only in the epithelium of ameloblastoma. The marked immunostaining of MMP-9 , MMP-13 and TIMP-1 in epithelium and mesenchyme of the lesion indicate that these proteins involved in ECM remodeling required for tumor progression, however, specific differences in the expression of some of these proteins, are not sufficient to suggest differences in the biological behavior of ameloblastomas and KOTs
Resposta celular Th1 /Th2 na doença periodontal experimental, em ratos: um estudo imuno-histoquímico
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Host response plays a major role in the pathogenesis of periodontal disease. Mediators such as inflammatory cytokines which are secreted during the immune response to bacterial challenges have ambiguous functions that may or may not lead to protection of the attacked tissue. In this context, experimental evidence suggests that T-helper 1 (Th-1) and T-helper 2 (Th-2) mediated responses are potentially important during the disease process. The aims of this study therefore were to further clarify the role played by Th2 cells during different time points of the active phase of periodontal disease, as well as, to investigate whether there was any evidence of a Th1 response in the periodontal disease microenvironment. Experimental periodontitis was induced in 30 Wistar male rats by placing cotton ligatures around the mandibular first molars. The rats were then randomly divided into two groups. Group1 (G1=15) and Group 2 (G2=15). In G1 the ligatures were maintained for 2 days, whereas in G2 the ligatures were left for 15 days, a time point that corresponds to the advanced stage of periodontal disease The contra-lateral teeth served as controls (no ligatures). Immunohistochemical investigation for the presence in gingival tissue of Th2 specific transcription factor (GATA3) and the subunit of the IFN-γ receptor was carried out after the disease induction period. Light microscopy analysis revealed a decrease in the expression of GATA-3 as bone loss progressed. On the other hand, although IFN-γ R1 was detected at an early stage of the active phase of disease its expression remained unaltered during the remaining period of the study. These results indicate that the Th2 response have a protective role during the pathogenesis of periodontal disease and that the progression of the periodontal disease is related with the unbalance of the responses Th1/Th2
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Oral squamous cell carcinoma (OSCC) is the most prevalent malignancy in the oral cavity and reach a large number of individuals, has become an important public health problem. Studies have demonstrated changes in pathway components BMP in various types of cancers as prostate, colon, breast, gastric and OSCCs. Is the current knowledge that these proteins may exert pro-tumor effect in more advanced stages of neoplastic development coming to favor progression and invasion tumor. The inhibition of the signaling pathway BMP-2 through its antagonists, have shown positive results of antitumor activity and use of Noggin may be a novel therapeutic target for cancer. Given this evidence and the few studies with BMP-2, Noggin and OSCC, the objective of this research was to evaluate the effect of BMP-2 and its antagonist Noggin on proliferation and migration cell in line of cell cultures of human tongue squamous cell carcinoma (SCC25). The study was divided in three groups, a control group, where SCC25 cells suffered no treatment, a BMP-2 group, in which cells were treated with 100ng/ml of BMP-2 and a group of cells that were treated with 100ng/ml of Noggin. For the proliferation assay and cell cycle were established three time intervals (24, 48 and 72 hours). Proliferative activity was investigated by trypan blue and cell cycle analysis by staining with propidium iodide flow cytometry. The potential for migration / invasion of SCC25 cells was performing by a cell invasion assay using Matrigel in a 48-hour interval. The proliferation curve showed a higher proliferation in cells treated with BMP-2 in 72 hours (p < 0.05), and lower overgrowth and cell viability in Noggin group. Recombinant proteins favored a greater percentage of cells in cell cycle phase Go/G1 with a statistically significant difference in the interval of 24 hours (p < 0.05). BMP- 2 produced a greater invasion of cells studied as well as its antagonist Noggin inhibits invasion of cells (p < 0.05). Thus, these results indicate that BMP-2 promotes malignant phenotype, dues stimulates proliferation and invasion of SCC25 cells and, its antagonist Noggin may be an alternative treatment, due to inhibit the tumor progression
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We analyzed the quality of raw milk from eight dairy farms in Rio Grande do Norte stored in a cooling tank , in order to evaluate methods for determining somatic cell counts (SCC). The Somaticell® kit and a portable Direct Cell Counter (DCC) were compared with each other and with the MilkoScanTM FT+ (FOSS Denmark), which uses Fourier Transform Infrared (FTIR) spectroscopy). Direct cell counter data were processed for somatic cell scores (log-transformed somatic cell count) and analyzed with the SAS®, statistical package , Statistical Analysis System, (SAS, INSTITUTE, 1998). Comparison of means and correlation of somatic cell scores were conducted using Pearson s correlation coefficient and the Tukey Test at 1 %. No significant difference was observed for comparison of means. The correlation between somatic cell scores was significant, that is, 0.907 and 0.876 between the MilkoScanTM FT+ and the Somaticell® kit and Direct Cell Count (DCC) respectively, and 0.943 between the Somaticell® kit and Direct Cell Count (DCC). The methods can be recommended for monitoring the quality of raw milk kept in a cooling tank in the production unit
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The visual system is an important link between the animal and the environment, com profound influences on the habits and lifestyle in various habitats. Adaptive mechanismsto the temporal niche are present in the visual system of many vertebrates, involving changins in ocular dimensios and design, retinal cell distribution and organization of neurochemical circuits related to the retinal resolution or sensitivity. The sensory system of the eye is represented by the retina, whose organization is responsible by receipty, initial analysis, and transmission of the information to the brain. The knowledge of the position of the eyes in the head and the distribution of retinal cells allow to identify adaptive aspects of each species to its visual field, which is characteristic to the ecological niche it occupies. In this research, we study eye anatomical characteristics and retina neurochemical features of the rock cavy (Kerodon rupestris), a tipical Brazilian rodent from the suborder Hystricomorpha, family Caviidae. The rock cavy has lateral eyes well constitute bony orbit and well differentiated extrinsic muscle. The study of the descriptive and morphometric anatomy of the showed mean values of axial diameter 10.7±0,5mm and equatorial diameter 11.6±0.7mm. The pupil is slit shaped and the lens has mean axial diameter 5.4±0.03 mm, corresponding to ~45% of the axial diameter of the eye. The posterior nodal distance and the retinal magnification factor were estimated at 6.74 mm e 118 μm/grau, respectively. Flat mounts were processed for Nissl stain, and the topographic distribution of ganglion cells showed a moderate visual band, just below the optic disc, with higher density in the ventral retina. Retinal vertical sections and flat mounts were processed for immunohistochemistry to visualize tyrosine hydroxilase (TH) and thus two types of TH+ cells were detected. Type 1 cells had strong TH-immunoreactivity, the body cell varied from 120.047 to 269.373 μm2 stratifying in the sublamina 1 of the IPL. Type 2 cells were weakly TH-imunoreactive, had cell body located mostly in the IPL, varying from 54.848 to 177.142 μm2, constituting ~10% of the TH+ cells. Both cell types exhibited similar topographic distribution with higher density found in a horizontal band along of the naso-temporal axis in the dorsal retina. The total population of dopaminergic cells was 2,156±469,4 cells, occupying an average area of 198,164 μm2. The presence of cones and rods was detected by immunohistochemistry in vertical sections and flat mounts. S cones density is around 10 times smaller than L cones, with different degree of spatial organization. Other retinal neuronal populations of the rock cavy were also detected in vertical sections with specific markers. Comparative analysis of the anatomical characteristics of the rock cavy eye 12 suggest that it was designed to acquire higher sensitivity to light, at expense of image sharpness, compatible with a vision at mesopic conditions. Additionally, the distribution of the 2 subtypes of dopaminergic cells in a naso-temporal band in the dorsal retina seems suitable to a gain in sensitivity, coherent with an animal with predominantly crepuscular activity pattern
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
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T. gondii is an obligate intracellular protozoan and the main cause of retinochoroiditis in humans. The aim of this study was to evaluate the effect of the antipsychotic drugs haloperidol and clozapine on the course of infection by T. gondii of cultured embryonic retinal cells. Embryo retinas of Gallus gallus domesticus (E12) were used for the preparation of mixed monolayer cultures of retinal cells. Cultures were maintained on plates of 96 and 24 wells by 37°C in DMEM medium supplemented with 5% fetal bovine serum for 2 days. After this period, cultures were simultaneously infected with tachyzoites of T. gondii and treated with the antipsychotics haloperidol and clozapine for 48 hours. Treatment effects were determined by both assessing cell viability with the MTT method and evaluating infection outcomes in slides stained with Giemsa. The treatment with haloperidol and clozapine cells infected with T. gondii resulted in higher viability of these cells, suggesting a possible prevention of neuronal degeneration induced by T. gondii. Additionally, intracellular replication of this protozoan in cells treated with haloperidol and clozapine were significantly reduced, possibly by modulation of the parasite s intracellular calcium concentration
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Perovskite-like ceramic materials present the general formula ABO3, where A is a rare earth element or an alkaline metal element, and B is a transition metal. These materials are strong candidates to assume the position of cathode in Solid Oxide Fuel Cells (SOFC), because they present thermal stability at elevated temperatures and interesting chemical and physical properties, such as superconductivity, dieletricity, magnetic resistivity, piezoelectricity, catalytic activity and electrocatalytic and optical properties. In this work the cathodes of Solid Oxide Fuel Cells with the perovskite structure of La1-xSrxMnO3 (x = 0.15, 0.22, 0.30) and the electrolyte composed of zirconia-stabilized-yttria were synthesized by the Pechini method. The obtained resins were thermal treatment at 300 ºC for 2h and the obtained precursors were characterized by thermal analysis by DTA and TG / DTG. The powder precursors were calcined at temperatures from 450 to 1350ºC and were analyzed using XRD, FTIR, laser granulometry, XRF, surface area measurement by BET and SEM methods. The pellets were sintered from the powder to the study of bulk density and thermal expansion
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The present work aims the preparation of filmes of strontium-doped lanthanum manganite (perovskita) yttria-stabilized zirconia (LSM-SDC) films deposited on substrate of YSZ by means of spin coating technique having as principal objective their application to solid oxide fuel cells of intermediate temperature. La0,8Sr0,2MnO3 and Ce0,8Sm0,2O1,9 were obtained by modified Pechini method by use of gelatin which act as polymerization agent. The powders obtained were characterized by Xray fluorescence, X ray diffraction, electronic scanning microscopy and the superficial area by BET method. The results obtained by X-ray fluorescence showed that the route adopted for obtention of powders was effective in the obtention of the compositions with close values to the stoichiometrics. Ethyl cellulose was used as pore-forming agent and mixed with the LSM-SDC powders in weight proportions of 1:24, 2:23 and 1:9. The films were sintered at 1150 °C for 4 h and characterized by X-ray diffraction and scanning electron microscopy technique (SEM) and atomic force. The phases quantification of the precursory powders and of the obtained films was carried through Rietveld method. According with the analysis of SEM, as the content of ethyl cellulose was increased, the pore distribution in films become more uniform and the pore size reduced. The methodology used for the obtention of the films was very efficient, considering a material was obtained with characteristics that were proper to the application as electrolyte/cathode system to solid oxide fuel cells
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Materials consisting of perovskite-type oxides (ABO3) have been developed in this work for applications in fuel cell cathodes of solid oxide type (SOFC). These ceramic materials are widely studied for this type of application because they have excellent electrical properties, conductivity and electrocatalytic. The oxides LaMnO3, LaFeO3, LaFe0.2Mn0.8O3 e La0.5Fe0.5MnO3 were synthesized by the method of microwave assisted combustion and after sintering at 800°C in order to obtain the desired phases. The powders were characterized by thermogravimetry (TG), X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and voltammetric analysis (cyclic voltammetry and polarization curves). The results obtained by XRF technique showed that the microwave synthesis method was effective in obtaining doping oxides with values near stoichiometric. In general, powders were obtained with particle size less than 0.5 μm, having a porous structure and uniform particle size distribution. The particles showed spherical form, irregular and crowded of varying sizes, according to the analysis of SEM. The behavior of the oxides opposite the thermal stability was monitored by thermogravimetric curves (TG), which showed low weight loss values for all samples, especially those of manganese had its structure. By means of Xray diffraction of the samples sintered at 800°C was possible to observe the formation of powders having high levels of crystallinity. Furthermore, undesirable phases such as La2O3 and MnOx were not identified in the diffractograms. These phases block the transport of oxygen ions in the electrode/electrolyte interface, affecting the electrochemical activity of the system. The voltammetric analysis of the electrocatalysts LF-800, LM-800, LF2M8-800 e L5F5M-800 revealed that these materials are excellent electrical conductors, because it increased the passage of electrical current of the working electrode significantly. Best performance for the oxygen reduction reaction was observed with iron-rich structures, considering that the materials obtained have characteristics suitable for use in fuel cell cathodes of solid oxide type
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Low level laser irradiation (LLLI) has been used in Dentistry to promote wound healing and tissue regeneration. The literature shows a positive effect of LLLI on cell proliferation, but little is known about their effectiveness in promoting stem cells proliferation. The aim of this study was to evaluate the effect of LLLI on the proliferative rate of human periodontal ligament stem cells. Extracts of periodontal ligament were isolated from two third molars removed by surgical and/or orthodontic indication. After enzymatic digestion, the cells were grown in α-MEM culture medium supplemented with antibiotics and 15% fetal bovine serum. On the third subculture, the cells were irradiated with a InGaAlP-diode laser, using two different energy densities (0,5J/cm 2 - 16 seconds and 1,0J/cm² - 33 seconds), with wavelength of 660nm and output power of 30mW. A new irradiation, using the same parameters, was performed 48h after the first. A control group (non irradiated) was kept under the same experimental culture conditions. The Trypan blue exclusion test and the mitochondrial activity of the cells measured by MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] essay were performed to assess the cell proliferation in the intervals of 0, 24, 48 e 72 h after irradiation. The data of cell counts were submitted to nonparametrical statistical tests (Kruskal-Wallis and Mann-Whitney), considering a confidence interval of 95%. DAPI (4 -6-Diamidino-2-phenylindole) staining of the cells was performed at 72h interval to evaluate possible nuclear morphological changes induced by LLLI. The results of this study show that the energy density of 1,0 J/cm² promoted greater cell proliferation compared to the other groups (control and 0,5 J/cm²) at intervals of 48 and 72h. The mitochondrial activity measured by MTT essay showed similar results to the Trypan blue cell counting test. The group irradiated with 1,0J/cm² exhibited a significantly higher MTT activity in the intervals of 48 and 72h, when compared to the group irradiated with 0,5J/cm². No nuclear morphological change was observed in the cells from the three groups studied. It is concluded that LLLI has stimulatory effects on the proliferation of human periodontal ligament stem cells. Therefore, the use of laser irradiation in this cell type may be important to promote future advances in periodontal regeneration
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Dental pulp stem cells have been widely investigated because of their ability to differentiate into both dental and non-dental cells, with potential use in therapies involving tissue engineering. The technique of cell cryopreservation represents a viable alternative for the conservation of these cells, since it stops reversibly, in a controlled manner, all of cell biological functions in an ultra low temperature. The present study aimed to evaluate, using in vitro experiments, the influence of a cryopreservation protocol on the biologic acti vity of stem cells from human exfoliated deciduous teeth (SHED). Cells obtained from the pulp of three deciduous teeth on end-stage exfoliation or with indicated extraction were expanded in α-MEM culture medium supplemented with antibiotics and 15% fetal bovine serum. At second subculture (P2), a group of cells were submitted to cryopreservation for 30 days in 10% DMSO diluted in fetal bovine serum, at -80º C, while the remind cells continued under normal conditions of cell culture. Cell proliferation was evaluated in both groups (not cryopreserved or cryopreserved) by Trypan blue stain essay at intervals of 24, 48 and 72h after plating. Cell cycle analysis of SHEDs submitted or not to the cryopreservation protocol was performed in the same intervals. Events related to cell death were studied by Annexyn V and PI expression under flow cytometry at the intervals of 24 and 72h. The presence of nuclear morphological changes was evaluated by DAPI staining at 72h interval. It was observed that both groups exhibited an upward cell proliferation curve, without considerable changes in cell viability throughout the experiment. The distribution of cell in the cell cycle phasis was consistent with cell proliferation in both groups. There were no nuclear morphological damages in the end range of the experiment. therefore, it is concluded that the proposed cryopreservation protocol is efficient for storing the studied cell type, allowing its use in future experimental studies
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The activation of hepatic stellate cells (HSC) is considered the most important event in hepatic fibrogenesis. The precise mechanism of this process is unknown in autoimmune hepatitis (AIH), and more evidence is needed on the evolution of fibrosis. The aim of this study was to assess these aspects in children with type 1 AIH. We analyzed 16 liver biopsy samples from eight patients, paired before treatment and after clinical remission, performed an immunohistochemical study with anti-actin smooth muscle antibody and graded fibrosisand inflammation on a scale of 0:4 (Batts and Ludwig scoring system). We observedthere was no significant reduction in fibrosis scores after 24± 18 months (2.5 ± 0.93 vs. 2.0± 0.53, P = 0.2012). There was an important decrease in inflammation: portal (2.6 ±0.74 vs. 1.3± 0.89, P = 0.0277), periportal/periseptal (3.0 ±0.76 vs. 1.4 ± 1.06, P = 0.0277), and lobular (2.8 ± 1.04 vs. 0.9± 0.99, P =0.0179). Anti-actin smooth muscle antibodies were expressed in the HSC of the initial biopsies (3491.93 ±2051.48 lm2), showing a significant reduction after remission (377.91 ±439.47 lm2) (P = 0.0117). HSC activation was demonstrated in the AIH of children. The reduction of this activation after clinical remission, which may precede a decrease in fibrosis, opens important perspectives in the follow-up of AIH.
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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