949 resultados para Bone marrow


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Aims: To report nine additional well-defined cases with infiltrative myelopathy by paracoccidioidomycosis (PCM), to describe the specific lesions and infection-related stromal abnormalities, to review the literature on this type of involvement and to introduce a new cause of granulomatous lesions of bone marrow.Methods and results: Different bone marrow specimens were studied (aspirated smears, aspirated clots, biopsy imprints and biopsies) from nine patients with acute or subacute forms of PCM known to have PCM infiltrative myelopathy.Conclusions: the biopsy specimens were the best for demonstrating bone marrow involvement by PCM. The lesions varied from compact and focal granulomas with few fungal cells to numerous disseminated fungal cells within a loose granulomatous inflammatory reaction, with a continuum between these extremes suggesting a spectrum of immune response to the fungi. Other findings such as bone marrow fibrosis, parenchymal coagulative necrosis and bone necrosis were also observed in the affected areas.

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In this work we have:investigated the growth and differentiation of bone marrow stem cells in mice bearing Ehrlich ascites tumor-and treated with three dose-regimens of Dicyclopentadienyldichlorotitanium (IV) (DDCT). We also: studied the presence of colony stimulating factors In the serum of PDCT-treated animals as well-as the effects-of the drug on the survival of the tumor-bearing mice. The-results demonstrated that the myelosuppression developed in the tumor-bearing animals is prevented by the administration:of 1, 2 or 3 doses of 15 mg/kg DDCT. In the treatment with three doses, however, 23 % of the animals died. Moreover, DDCT treatment in normal animals resulted in increased numbers of CFU-GM. We observed the presence of stimulating factors in the serum of drug-treated animals which induced the growth and differentiation of bone marrow progenitor cells from normal animals in vitro. on the other hand, in vitro addition of the drug to these cultures had no effect. Thus, we conclude that the drug protects against the myelosuppression induced by the tumor and that this protection may be related to an indirect action of the drug. (C) 1998 International Society for Immunopharmacology. Published by Elsevier B.V. Ltd.

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Several studies have suggested that dietary supplementation with antioxidants can influence the response to chemotherapy as well as the development of adverse side effects that result from treatment with antineoplastic agents. The emphasis of the present study was to investigate whether the administration of a single dose of oral glutamine had any protective effect against cisplatin-induced clastogenicity. Cisplatin was administered to Wistar rats either alone or after treatment with glutamine. The rats were treated with glutamine (300 mg/kg b.w.) by gavage 24 h before the administration of cisplatin (5 mg/kg b.w., i.p.) and then sacrificed 24h after treatment with cisplatin. Glutamine significantly reduced (by about 48%) the clastogenicity of cisplatin in rat bone marrow cells. The antioxidant action of glutamine presumably modulates the clastogenic action of cisplatin. (C) 2002 Elsevier B.V. B.V. All rights reserved.

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Objectives. Alterations in the commercially pure titanium (cpTi) surface may be undertaken to improve its biological properties. The aim of this study is to investigate the biocompatibility of cpTi submitted to different surface treatments.Methods. The cpTi surfaces were prepared so that machined and blasted surfaces, either acid etched or not, were compared using rat bone marrow cells cultured to differentiated into osteoblast. For attachment evaluation, cells were cultured for 4 and 24 h. Cell morphology was evaluated after 3 days. After 7, 14, and 21 days cell proliferation was evaluated. Total protein content and alkaline phosphatase (ALP) activity were evaluated after 14 and 21 days. For bone-like nodule formation, cells were cultured for 21 days. Data were compared by analysis of variance.Results. Cell attachment, cell morphology, cell proliferation, and ALP activity were not affected by surface treatments. Total. protein content was reduced by blasted and acid etched surface. Bone-Like nodule formation was significantly reduced by blasted, acid etched, and a combination of both blasted and acid etched surfaces.Conclusions. Based on these results, it can be suggested that cpTi surfaces that were submitted only to machining treatment favor the final event of osteoblastic differentiation of the rat bone marrow cells, evidenced by increased bone-Like nodule formation. (C) 2003 Elsevier B.V. Ltd. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Most manufactured foods contain chemicals added as a deliberate part of the manufacturing process. The aims of the present study were to evaluate the mutagenicity and antimutagenicity of annatto, a natural pigment extracted from the Bixa orellana L. and widely used as a colorant in foods. The micronucleus test was performed in bone marrow cells from Swiss male mice treated with one of the three concentrations of annatto (1330, 5330 and 10,670 ppm), incorporated into the diet. The animals were fed with the diets for 7 days and sacrificed 24 h after the last treatment. For the evaluation of the antimutagenic potential of annatto, at day 7, the animals received an intraperitoneal injection of cyclophosphamide (50 mg/kg body weight). Under the concentrations tested annatto did not present mutagenic or antimutagenic activities on the mice bone marrow cells. However, an increased frequency of micronucleated cells was observed when the highest concentration (10,670 ppm) was administered simultaneously with cyclophosphamide. In conclusion, the data indicate that annatto colour, for the conditions used, is neither mutagenic nor an inhibitor of induced mutations, although it should be used carefully since high doses may increase the effect of a mutagen. © 2003 Elsevier Science Ltd. All rights reserved.

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Investigation of the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in chronic myeloid leukemia patients is essential to predict prognosis and survival. In 20 patients treated at the Bone Marrow Transplantation Unit of São José do Rio Preto (São Paulo, Brazil), we used fluorescence in situ hybridization (FISH) to investigate the frequency of cells with BCR/ABL rearrangement at diagnosis and at distinct intervals after allo-HSCT until complete cytogenetic remission (CCR). We investigated the disease-free survival, overall survival in 3 years and transplant-related mortality rates, too. Bone marrow samples were collected at 1, 2, 3, 4, 6, 12, and 24 months after transplantation and additional intervals as necessary. Success rate of the FISH analyses was 100%. CCR was achieved in 75% of the patients, within on average of 3.9 months; 45% patients showed CCR within 60 days after HSCT. After 3 years of the allo-HSCT, overall survival rate was 60%, disease-free survival was 50% and the transplant-related mortality rate was 40%. The study demonstrated that the BCR-ABL FISH assay is useful for follow-up of chronic myeloid leukemia patients after HSCT and that the clinical outcome parameters in our patient cohort were similar to those described for other bone marrow transplantation units. ©FUNPEC-RP.

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Aim: Nowadays, research on orthopedic and dental implants is focused on titanium alloys for their mechanical properties and corrosion resistance in the human body environment. Another important aspect to be investigated is their surface topography, which is very important to osseointegration. With laser beam irradiation for roughening the implants surface an easier control of the microtopography is achieved, and surface contamination is avoided. The aim of this study was to assess human bone marrow stem cells response to a newly developed titanium alloy, Ti-15Mo, with surface topography modified by laser beam irradiation. Materials and methods: A total of 10 Ti machined disks (control), 10 Ti-15Mo machined disks and 10 Ti-15Mo disks treated by laser beam-irradiation were prepared. To study how Ti-15Mo surface topografy can induce osteoblast differentiation in mesenchymal stem cells, the expression levels of bone related genes and mesenchymal stem cells marker were analyzed, using real time Reverse Transcription-Polymerase Chain Reaction. Results: In Test 1 (comparison between Ti-15Mo machined disks and Ti-machined disks) quantitative real-time RT-PCR showed a significant induction of ALPL, FOSL1 and SPP1, which increase 20% or more. In Test 2 (comparison between Ti-15Mo laser treated disks and Ti-machined disks) all investigated genes were up-regulated. By comparing Test 1 and Test 2 it was detected that COL1A1, COL3A1, FOSL1 and ENG sensibly increased their expression whereas RUNX2, ALPL and SPP1 expression remained substantially unchanged. Conclusion: The present study demonstrated that laser treated Ti-15Mo alloys are promising materials for implants application.

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Objective. The aim of this study was to evaluate the bone healing after the usage of a scaffold enriched with bone marrow. Study Design. Ten rabbits were divided into 2 groups of 5 animals. Bilateral 12 mm diameter defects were created in the parietal bones. In control group Bio-Oss were inserted in both defects and, in experimental group, Bio-Oss enriched with autologous bone marrow were inserted in both defects. In these two groups, one of the calvarial defects was covered with Bio-Gide. The rabbits were sacrified 8 weeks after surgery and both CT and histomorphometric analysis were done. Results. The CT showed a lower remaining defect area in the experimental group covered with Bio-Gide when compared with control group, with and without Bio-Gide. The histomorphometrics showed no difference between groups regarding the non-vital mineralized tissue area. For vital mineralized tissue area, the experimental group covered with Bio-Gide obtained a higher percentage area when compared with control group, with and without Bio-Gide. For non-mineralized tissue area, the experimental group covered with Bio-Gide obtained a lower percentage area when compared with control group, with and without Bio-Gide. Conclusion. Both autologous bone marrow and membrane can contribute to the enhancement of bone healing. Copyright © 2012 Marcelo de Oliveira e Silva et al.

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Model of study: Experimental study. Introduction: Recently, stem cell research has generated great interest due to its applicability in regenerative medicine. Bone marrow is considered the most important source of adult stem cells and the establishment of new methods towards gene expression analysis regarding stem cells has become necessary. Thus Differential Display Reverse Transcription Polymerase Chain Reaction (DDRT-PCR) may be an accessible tool to investigate small differences in the gene expression of different stem cells in distinct situations. Aim: In the present study, we investigated the exequibility of DDRT-PCR to identify differences in global gene expression of mice bone marrow cells under two conditions. Methods: First, bone marrow cells were isolated fresh and a part was cultivated during one week without medium replacement. Afterwards, both bone marrow cells (fresh and cultivated) were submitted to gene expression analyses by DDRT-PCR. Results: Initially, it was possible to observe in one week-cultured bone marrow cells, changes in morphology (oval cells to fibroblastic-like cells) and protein profile, which was seen through differences in band distribution in SDS-Page gels. Finally through gene expression analysis, we detected three bands (1300, 1000 and 225 bp) exclusively expressed in the fresh bone marrow group and two bands (400 and 300 bp) expressed specifically in the cultivated bone marrow cell group. Conclusions: In summary, the DDRT-PCR method was proved efficient towards the identification of small differences in gene expression of bone marrow cells in two defined conditions. Thus, we expect that DDRT-PCR can be fast and efficiently designed to analyze differential gene expression in several stem cell types under distinct conditions.