182 resultados para Bone-marrow Transplantation

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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The purpose of this study was to determine whether bone marrow-derived cells can differentiate into myofibroblasts, as defined by alpha-smooth muscle actin (SMA) expression, that arise in the corneal stroma after irregular phototherapeutic keratectomy and whose presence within the cornea is associated with corneal stromal haze. C578L/6J-GFP chimeric mice were generated through bone marrow transplantation from donor mice that expressed enhanced green fluorescent protein (GFP) in a high proportion of their bone marrow-derived cells. Twenty-four GFP chimeric mice underwent haze-generating corneal epithelial scrape followed by irregular phototherapeutic keratectomy (PTK) with an excimer laser in one eye. Mice were euthanized at 2 weeks or 4 weeks after PTK and the treated and control contralateral eyes were removed and cryo-preserved for sectioning for immunocytochemistry. Double immunocytochemistry for GFP and myofibroblast marker alpha-smooth muscle actin (SMA) were performed and the number of SMA+GFP+, SMA+GFP, SMA-GFP+ and SMA GFP cells, as well as the number of DAPI+ cell nuclei, per 400x field of stroma was determined in the central, mid-peripheral and peri-limbal cornea. In this mouse model, there were no SMA+ cells and only a few GFP+ cells detected in unwounded control corneas. No SMA+ cells were detected in the stroma at two weeks after irregular PTK, even though there were numerous GFP+ cells present. At 4 weeks after irregular PTK, all corneas developed mild to moderately severe corneal haze. In each of the three regions of the corneas examined, there were on average more than 9x more SMA+GFP+ than SMA+GFP myofibroblasts. This difference was significant (p < 0.01). There were significantly more (p < 0.01) SMA GFP+ cells, which likely include inflammatory cells, than SMA+GFP+ or SMA+GFP cells, although SMA GFP cells represent the largest population of cells in the corneas. In this mouse model, the majority of myofibroblasts developed from bone marrow-derived cells. It is possible that all myofibroblasts in these animals developed from bone marrow-derived cells since mouse chimeras produced using this method had only 60-95% of bone marrow-derived cells that were GFP+ and it is not possible to achieve 100% chimerization. This model, therefore, cannot exclude the possibility of myofibroblasts also developed from keratocytes and/or corneal fibroblasts. (C) 2010 Elsevier Ltd. All rights reserved.

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Background: Myocardial infarction remains as a major cause of mortality worldwide and a high rate of survivors develop heart failure as a sequel, resulting in a high morbidity and elevated expenditures for health system resources. We have designed a multicenter trial to test for the efficacy of autologous bone marrow (ABM) mononuclear cell (MC) transplantation in this subgroup of patients. The main hypothesis to be tested is that treated patients will have a significantly higher ejection fraction (EF) improvement after 6 months than controls. Methods: A sample of 300 patients admitted with ST elevation acute myocardial infarction (STEMI) and left ventricle (LV) systolic dysfunction, and submitted to successful mechanical or chemical recanalization of the infarct-related coronary artery will be selected for inclusion and randomized to either treated or control group in a double blind manner. The former group will receive 100 x 106 MC suspended in saline with 5% autologous serum in the culprit vessel, while the latter will receive placebo (saline with 5% autologous serum). Implications: Many phase I/II clinical trials using cell therapy for STEMI have been reported, demonstrating that cell transplantation is safe and may lead to better preserved LV function. Patients with high risk to develop systolic dysfunction have the potential to benefit more. Larger randomized, double blind and controlled trials to test for the efficacy of cell therapies in patients with high risk for developing heart failure are required.

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Spleen or spleen plus bone marrow cells from (BALB/c x C57Bl/6)F1 donors were transferred into BALB/c recipients 21 days before skin or cardiac transplantation. Prolonged graft survival was observed on recipients treated with the mixture of donor-derived cells as compared to those treated with spleen cells alone. We evaluated the expression of CD45RB and CD44 by splenic CD4(+) and CD8(+) T cells 7 and 21 days after donor cell transfer. The populations of CD8(+)CD45RB(low) and CD8(+)CD44(high) cells were significantly decreased in mice pre-treated with donor spleen and bone marrow cells as compared to animals treated with spleen cells only, although these cells expanded in both groups when compared to an earlier time-point. No differences were observed regarding CD4+ T cell population when recipients of donor-derived cells were compared. An enhanced production of IL-10 was observed seven days after transplantation in the supernatants of spleen cell cultures of mice treated with spleen and bone marrow cells. Taken together these data suggest that donor-derived bone marrow cells modulate the sensitization of the recipient by semi-allogeneic spleen cells in part by delaying the generation of activated/memory CD8(+) T cells leading to enhanced graft survival. (c) 2007 Elsevier B.V. All rights reserved.

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Background: Since the cell therapy benefits for myocardial infarction are mainly related to infarct reduction by regenerating lost myocardium or increasing survival of tissues at risk, we evaluated the effects of bone marrow-derived mononuclear cells (MNC), implanted after the completion of necrosis, on infarct progression and cardiac remodeling. Methods: After 48 h of induction of myocardial infarction (MI), Lewis-inbred rats were injected with 6 x 10(6) cells (MI + MNC) or saline (MI). After six weeks, scar dimension, ventricular morphology and function were analyzed by echocardiography followed by histomorphology of the infarcted and border zones. Results: After therapy, the relative size of the infarct was smaller in MI + MNC (37 +/- 1% of the left ventricle) than in MI (43 +/- 1%). While the MI group exhibited parallel elongation of the infarcted (31.6 +/- 3.8% increase) and reminiscent ventricular portions (33.5 +/- 3.7%), MNC therapy preserved the initial infarct length. Infarcted walls were thicker (979 +/- 31 mm) in the MNC group than in the untreated group (709 +/- 41 mm), also demonstrating an absence of infarct expansion. In the border zones, MNC led to increased capillary densities and capillary/myocyte ratios. The cardiac systolic function remained depressed in MI, but improved by 19 +/- 5% in MI + MNC which reduced the incidence of pulmonary arterial hypertension (37.5% in MI and 6.25% in MI + MNC). Conclusion: MNC therapy prevented the infarct expansion and thinning related to cardiac remodeling and was associated with an improvement of border zone microcirculation: as a result, MNC therapy reduced typical MI dysfunctional repercussions. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

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Autologous bone marrow mononuclear cell (BMMC) transplantation has emerged as a potential therapeutic option for refractory angina patients. Previous studies have shown conflicting myocardium reperfusion results. The present study evaluated safety and efficacy of CellPraxis Refractory Angina Cell Therapy Protocol (ReACT). in which a specific BMMC formulation was administered as the sole therapy for these patients. The phase I/IIa noncontrolled, open label. clinical trial, involved eight patients with refractory angina and viable ischemic myocardium, without left ventricular dysfunction and who were not suitable for conventional myocardial revascularization. ReACT is a surgical procedure involving a single series of multiple injections (40-90 injections, 0.2 ml each) into ischemic areas of the left ventricle. Primary endpoints were Canadian Cardiovascular Society Angina Classification (CCSAC) improvement at 18 months follow-up and myocardium ischemic area reduction (assessed by scintigraphic analysis) at 12 months follow-up, in correlation with a specific BMMC formulation. Almost all patients presented progressive improvement in angina classification beginning 3 months (p = 0.008) postprocedure which was sustained at 18 months follow-up (p = 0.004), as well as objective myocardium ischemic area reduction at 12 months (decrease of 84.4%, p < 0.004). A positive correlation was found between monocyte concentration and CCSAC improvement (r = -0.759, p < 0.05). Improvement in CCSAC, followed by correlated reduction in scintigraphic myocardium ischemic area, strongly suggests neoangiogenesis as the main stem cell action mechanism. The significant correlation between number of monocytes and improvement strongly supports a cell-related effect of ReACT. ReACT appeared safe and effective.

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Objective The purpose of this study was to evaluate the efficacy of a centrifuged osteogenic bone marrow aspirate to stimulate healing in rabbit fibular osteotomies Methods Ten white New Zealand rabbits were used A transverse medial diaphyseal fibular osteotomy was performed on the right fibula where an absorbable collagen sponge embedded in osteogenic centrifuged bone marrow aspirate obtained from the ipsilateral iliac bone was inserted The left fibula was used as the control group where the collagen absorbable sponge was inserted without the osteogenic centrifuged aspirate The rabbits were sacrificed four weeks after surgery to evaluate bone callus formation Analyses of results were performed with DEXA bone densitometry to evaluate callus mineral mass multislice computed tomography to evaluate callus volume and histomorphometry to evaluate the relative rate of tissue formation Results The employment of centrifuged osteogenic bone marrow aspirate resulted in a 40 3% increase of callus bone mineral mass and increased relative quantity of bone tissue formation by 9 4% without a significant increase in the relative quantities of cartilage fibrous tissue or in callus volume Conclusions This study shows that the centrifuged osteogenic bone marrow aspirate was able to improve the healing of experimental fibular osteotomies in rabbits

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The aim of this study was to test the hypothesis that bone marrow mononuclear cell (BMDMC) therapy led an improvement in lung mechanics and histology in endotoxin-induced lung injury. Twenty-four C57BL/6 mice were randomly divided into four groups (n = 6 each). In the acute lung injur;y (ALI) group, Escherichia coli lipopolysaccharide (LPS) was instilled intratracheally (40 mu g, IT), and control (C) mice received saline (0.05 ml, IT). One hour after the administration of saline or LPS, BMDMC (2 x 10(7) cells) was intravenously injected. At day 28, animals were anesthetized and lung mechanics [static elastance (E(st)), resistive (Delta P(1)), and viscoelastic (Delta P(2)) pressures] and histology (light and electron microscopy) were analyzed. Immunogold electron microscopy was used to evaluate if multinucleate cells were type II epithelial cells. BMDMC therapy prevented endotoxin-induced lung inflammation, alveolar collapse, and interstitial edema. In addition, BMDMC administration led to epithelial and endothelial repair with multinucleated type II pneumocytes. These histological changes yielded a reduction in lung E(st), Delta P(1), and Delta P(2) compared to ALI. In the present experimental ALI model, the administration of BMDMC yielded a reduction in the inflammatory process and a repair of epithelium and endothelium, reducing the amount of alveolar collapse, thus leading to an improvement in lung mechanics.

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Cell therapy constitutes a possibility for improving nerve regeneration, increasing the success of nerve repair. We evaluate the use of mononuclear cells in the regeneration of the sciatic nerve after axotomy followed by end-to-end neurorrhaphy. Forty adult male Wistar rats (250300 g) were divided into four groups: (1) sham, (2) neurorrhaphy: the sciatic nerve was sectioned and repaired using epineural sutures, (3) culture medium: after the suture, received an injection of 10 mu L of culture medium into the nerve, and (4) mononuclear cell: after the suture, a concentration of 3 X 10(6) of mononuclear cell was injected in epineurium region. Mononuclear cells were obtained from the bone marrow aspirates and separated by Ficoll-Hypaque method. The histological analyses were performed at the 4th postoperative day. The sciatic functional index, histological, and morphometric analyzes were used to evaluate nerve regeneration at the 6th postoperative week. Six rats were used for immunohistochemical analysis on the 4th postoperative day. In the group 4, on the fourth day, the histological analysis demonstrated a more accelerated degenerative process and an increase of the neurotrophic factors was observed. In the 6th week, all the morphometric results of the group 4 were statistically better compared with groups 2 and 3. There was a statistically significant improvement in the sciatic functional index for group 4 compared with groups 2 and 3. Mononuclear cells stimulated nerve regeneration, most probably by speeding up the Wallerian degeneration process as well as stimulating the synthesis of neurotrophic factors. Microsc. Res. Tech. 74:355-363, 2011. (C) 2010 Wiley-Liss, Inc.

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Background. Mesenchymal stem cells (MSCs) are an attractive source for generation of cells with beta-cell properties. Previous studies have demonstrated the ability of prolactin to induce an increase in beta-cell mass and maturation, which suggests beneficial effects of its use in MSC differentiation protocols. Objective. To evaluate the expression of endocrine differentiation markers in rat MSCs treated in vitro with prolactin. Methods. Mesenchymal stem cells from bone marrow of Wistar rats were isolated, expanded, and characterized. Differentiation of MSCs was induced in medium containing 23 mmol/L of glucose, and nicotinamide, 2-mercaptoethanol, and exendin-4, in the presence or absence of 500 ng/mL of rat recombinant prolactin. Expression of endocrine markers and prolactin receptor genes was evaluated using real-time polymerase chain reaction, and compared between culture stages and presence vs absence of prolactin in the culture medium. Expression of insulin, somatostatin, glucagon, and pancreatic and duodenal homeobox 1 was also evaluated at immunofluorescence microscopy. Results. Isolated cells were mostly MSCs, as confirmed at fluorescent-activated cell sorting and cytochemistry. Pax6, Ngn-3, Isl1, NeuroD1, Nkx2.2, and Nkx6.1 exhibited varied expression during culture stages. The long form of the prolactin receptor messenger RNA was induced in prolactin-treated cultures (P < .05). The somatostatin gene was induced in early stages of differentiation (P < .05), and its expression was induced by prolactin, as confirmed using immunofluorescence. Conclusion. Culture of rat bone marrow MSCs in differentiation medium induces expression of pancreatic endocrine-specific genes, and somatostatin and prolactin receptor expression was also induced by prolactin.

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The broad use of transgenic and gene-targeted mice has established bone marrow-derived macrophages (BMDM) as important mammalian host cells for investigation of the macrophages biology. Over the last decade, extensive research has been done to determine how to freeze and store viable hematopoietic human cells; however, there is no information regarding generation of BMDM from frozen murine bone marrow (BM) cells. Here, we establish a highly efficient protocol to freeze murine BM cells and further generate BMDM. Cryopreserved murine BM cells maintain their potential for BMDM differentiation for more than 6 years. We compared BMDM obtained from fresh and frozen BM cells and found that both are similarly able to trigger the expression of CD80 and CD86 in response to LPS or infection with the intracellular bacteria Legionella pneumophila. Additionally, BMDM obtained from fresh or frozen BM cells equally restrict or support the intracellular multiplication of pathogens such as L. pneumophila and the protozoan parasite Leishmania (L.) amazonensis. Although further investigation are required to support the use of the method for generation of dendritic cells, preliminary experiments indicate that bone marrow-derived dendritic cells can also be generated from cryopreserved BM cells. Overall, the method described and validated herein represents a technical advance as it allows ready and easy generation of BMDM from a stock of frozen BM cells.

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Background: Mast cells have recently gained new importance as immunoregulatory cells that are involved in numerous pathological processes. One result of these processes is an increase in mast cell numbers at peripheral sites. This study was undertaken to determine the mast cell response in the peritoneal cavity and bone marrow during repopulation of the peritoneal cavity in rats. Results: Two mast cell specific antibodies, mAb AA4 and mAb BGD6, were used to distinguish the committed mast cell precursor from more mature mast cells. The peritoneal cavity was depleted of mast cells using distilled water. Twelve hours after distilled water injection, very immature mast cells could be isolated from the blood and by 48 hours were present in the peritoneal cavity. At this same time the percentage of mast cells in mitosis increased fourfold. Mast cell depletion of the peritoneal cavity also reduced the total number of mast cells in the bone marrow, but increased the number of mast cell committed precursors. Conclusions: In response to mast cell depletion of the peritoneal cavity, a mast cell progenitor is released into the circulation and participates in repopulation of the peritoneal cavity, while the committed mast cell precursor is retained in the bone marrow.

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Background: The D-mannose binding lectin ArtinM is known to recruit neutrophils, to degranulate mast cells and may have potential therapeutic applications. However, the effect of ArtinM on mast cell recruitment has not been investigated. Methodology: Male Wistar rats were injected i.p. with ArtinM or ConA (control). The ability of the lectin to degranulate peritoneal and mesenteric mast cells was examined. Recruitment of mast cells to the peritoneal cavity and mesentery after ArtinM injection was examined with or without depletion of peritoneal mast cells by distilled water. Results: ArtinM degranulated both peritoneal and mesentery mast cells in vitro. Three days after i.p. injection of the lectin there were reduced numbers of mast cells in the peritoneal lavage, while at 7 days post injection of ArtinM, the number of peritoneal mast cells was close to control values. Since immature mast cells are recruited from the bone marrow, the effect of the lectin on bone marrow mast cells was examined. Injection of ArtinM resulted in an increased number of mast cells in the bone marrow. To determine if degranulation of mast cells in the peritoneal cavity was required for the increase in bone marrow mast cells, the peritoneal cavity was depleted of mast cells with ultrapure water. Exposure to ArtinM increased the number of mast cells in the bone marrow of rats depleted of peritoneal mast cells. Conclusions: The ArtinM induced recruitment of mast cells from the bone marrow to the peritoneal cavity may partially explain the therapeutic actions of ArtinM.

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Purpose: To evaluate the expression of NF-kappa B pathway genes in total bone marrow samples obtained from MM at diagnosis using real-time quantitative PCR and to evaluate its possible correlation with disease clinical features and survival. Material and methods: Expression of eight genes related to NF-kappa B pathway (NFKB1, IKB, RANK, RANKL, OPG, IL6, VCAM1 and ICAM1) were studied in 53 bone marrow samples from newly diagnosed MM patients and in seven normal controls, using the Taqman system. Genes were considered overexpressed when tumor expression level was at least four times higher than that observed in normal samples. Results: The percentages of overexpression of the eight genes were: NFKB1 0%, IKB 22.6%, RANK 15.1%, RANKL 31.3%, OPG 7.5%, IL6 39.6%, VCAM1 10% and ICAM1 26%. We found association between IL6 expression level and International Staging System (ISS) (p = 0.01), meaning that MM patients with high ISS scores have more chance of overexpression of IL6. The mean value of ICAM1 relative expression was also associated with the ISS score (p = 0.02). Regarding OS, cases with IL6 overexpression present worse evolution than cases with IL6 normal expression (p = 0.04). Conclusion: We demonstrated that total bone marrow aspirates can be used as a source of material for gene expression studies in MM. In this context, we confirmed that IL6 overexpression was significantly associated with worse survival and we described that it is associated with high ISS scores. Also, ICAM1 was overexpressed in 26% of cases and its level was associated with ISS scores.

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During fetal development, mesenchymal progenitor (MP) cells are co-localized in major hematopoietic territories, such as yolk sac (YS), bone marrow (BM), liver (LV), and others. Studies using mouse and human MP cells isolated from fetus have shown that these cells are very similar but not identical to adult mesenchymal stem cells (MSC). Their differentiation potential is usually restricted to production of highly committed osteogenic and chondrogenic precursors. Such properties of fetal MP cells can be very useful for tissue regeneration, when a great number of committed precursors are required. The objectives of this study were to isolate and characterize MP cells from canine YS, BM, and LV in early and late stages of fetal development. Gestational stage was identified, and cell culture conditions were evaluated for efficient isolation of canine MP cells. All canine fetal MP cells expressed vimentin, nestin, and CD44 proteins. Cytokeratin 18 expression was observed in BM-and LV-MP cells, and vascular endothelial (VE)-cadherin expression was observed only in YS-MP cells. A small number of MP cells (5%) from LV and YS expressed Oct3/4 protein. The differentiation potential of canine fetal MP cells varied significantly: YS- and BM-MP cells differentiated into bone and cartilage, whereas LV-MP cells differentiation was limited to osteogenic fate. None of the canine fetal MP cells were able to differentiate into adipose cells. Our data suggest that canine fetal MP cells are an appropriate in vitro model to study MP biology from hematopoietic territories and they are a source of committed osteogenic and chondrogenic precursors for regenerative medicine.

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Background Data and Objective: Oral mucositis (OM) is one of the worst cytotoxic effects of chemotherapy and radiotherapy in patients undergoing hematopoietic cell transplantation (HCT), and it causes severe morbidity. Laser phototherapy has been considered as an alternative therapy for prevention and treatment of OM. The aim of this study was to describe the incidence and severity of OM in HCT patients subjected to laser phototherapy, and to discuss its effect on the oral mucosa. Patients and Methods: Information concerning patient age and gender, type of basic disease, conditioning regimen, type of transplant, absence or presence of pain related to the oral cavity, OM grade, and adverse reactions or unusual events were collected from 30 patients undergoing HCT (allogeneic or autologous). These patients were given oral laser phototherapy with a InGaAIP laser (660 nm and 40 mW) daily. The data were tabulated and their frequency expressed as percentages. Results: In the analysis of those with OM, it was observed that 33.4% exhibited grade I, 40% grade II, 23.3% grade III, and 3.3% grade IV disease. On the most critical post-HCT days (D+5 and D+8), it was observed that 63.3% of patients had grade I and 33.3% had grade II disease; no patients had grade III or IV disease in this period. This severity of OM was similar to that seen in other studies of laser phototherapy and OM. Conclusion: The low grades of OM observed in this survey show the beneficial effects of laser phototherapy, but randomized clinical trials are necessary to confirm these findings.