954 resultados para NEURAL STEM CELL


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Malaria is an unusual complication after hematopoietic stem cell transplantation in non-endemic countries. However, transplant candidates, recipients and donors living in endemic regions frequently report previous episodes of malaria. This fact could represent an important risk for immunosuppressed recipients that could develop severe malaria cases. We report a case of hematopoietic stem cell transplant (HSCT) in which the donor had a history of previous malaria, and close monitoring was performed before and after procedure by parasitological and molecular tests. The donor presented Plasmodium vivax in thick blood smears one month after transplant and was treated according to Brazilian Health Ministry guidelines. The polymerase chain reaction (PCR) was able to detect malaria infection in the donor one week earlier than thick blood film. Even without positive results, the recipient was pre-emptively treated with chloroquine in order to prevent the disease. We highlight the importance of monitoring recipients and donors in transplant procedures with the aim of reducing the risk of malaria transmission.

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We describe the rate of incidence of Clostridium difficile-associated diarrhea (CDAD) in hematologic and patients undergone stem cell transplant (HSCT) at HC-FMUSP, from January 2007 to June 2011, using two denominators 1,000 patient and 1,000 days of neutropenia and the risk factors associated with the severe form of the disease and death. The ELISA method (Ridascreen-Biopharm, Germany) for the detections of toxins A/B was used to identify C. difficile. A multivariate analysis was performed to evaluate potential factors associated with severe CDAD and death within 14 days after the diagnosis of CDAD, using multiple logistic regression. Sixty-six episodes were identified in 64 patients among 439 patients with diarrhea during the study period. CDA rate of incidence varied from 0.78 to 5.45 per 1,000 days of neutropenia and from 0.65 to 5.45 per 1,000 patient-days. The most common underlying disease was acute myeloid leukemia 30/64 (44%), 32/64 (46%) patients were neutropenic, 31/64 (45%) undergone allogeneic HSCT, 61/64 (88%) had previously used antibiotics and 9/64 (13%) have severe CDAD. Most of the patients (89%) received treatment with oral metronidazole and 19/64 (26%) died. The independent risk factors associated with death were the severe form of CDAD, and use of linezolid.

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Oral busulfan is the historical backbone of the busulfan+cyclophosphamide regimen for autologous stem cell transplantation. However intravenous busulfan has more predictable pharmacokinetics and less toxicity than oral busulfan; we, therefore, retrospectively analyzed data from 952 patients with acute myeloid leukemia who received intravenous busulfan for autologous stem cell transplantation. Most patients were male (n=531, 56%), and the median age at transplantation was 50.5 years. Two-year overall survival, leukemia-free survival, and relapse incidence were 67±2%, 53±2%, and 40±2%, respectively. The non-relapse mortality rate at 2 years was 7±1%. Five patients died from veno-occlusive disease. Overall leukemia-free survival and relapse incidence at 2 years did not differ significantly between the 815 patients transplanted in first complete remission (52±2% and 40±2%, respectively) and the 137 patients transplanted in second complete remission (58±5% and 35±5%, respectively). Cytogenetic risk classification and age were significant prognostic factors: the 2-year leukemia-free survival was 63±4% in patients with good risk cytogenetics, 52±3% in those with intermediate risk cytogenetics, and 37 ± 10% in those with poor risk cytogenetics (P=0.01); patients ≤50 years old had better overall survival (77±2% versus 56±3%; P<0.001), leukemia-free survival (61±3% versus 45±3%; P<0.001), relapse incidence (35±2% versus 45±3%; P<0.005), and non-relapse mortality (4±1% versus 10±2%; P<0.001) than older patients. The combination of intravenous busulfan and high-dose melphalan was associated with the best overall survival (75±4%). Our results suggest that the use of intravenous busulfan simplifies the autograft procedure and confirm the usefulness of autologous stem cell transplantation in acute myeloid leukemia. As in allogeneic transplantation, veno-occlusive disease is an uncommon complication after an autograft using intravenous busulfan.

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Epstein-Barr virus (EBV)-related post-transplant lymphoproliferative disease (PTLD) is one of the most serious complications associated with solid organ and hematopoietic stem cell transplantation. PTLD is most frequently seen with primary EBV infection post-transplant, a common scenario for pediatric solid organ recipients. Risk factors for infection or reactivation of EBV following solid organ transplant are stronger immunosuppressive therapy regimens, and being seronegative for receptor. For hematopoietic stem cell transplantation, the risk factors relate to the type of transplant, human leukocyte antigen disparity, the use of stronger immunosuppressants, T-cell depletion, and severe graft-versus-host disease. Mortality is high, and most frequent in patients who develop PTLD in the first six months post-transplant. The primary goal of this article is to provide an overview of the clinical manifestations, diagnosis, accepted therapies, and management of EBV infection in transplant recipients, and to suggest that the adoption of monitoring protocols could contribute to a reduction in related complications.

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 The success of synthetic bone implants requires good interface between the material and the host tissue. To study the biological relevance of fi bronectin (FN) density on the osteogenic commitment of human bone marrow mesenchymal stem cells (hBMMSCs), human FN was adsorbed in a linear density gradient on the surface of PCL. The evolution of the osteogenic markers alkaline phosphatase and collagen 1 alpha 1 was monitored by immunohistochemistry, and the cytoskeletal organization and the cell-derived FN were assessed. The functional analysis of the gradient revealed that the lower FN-density elicited stronger osteogenic expression and higher cytoskeleton spreading, hallmarks of the stem cell commitment to the osteoblastic lineage. The identifi cation of the optimal FN density regime for the osteogenic commitment of hBM-MSCs presents a simple and versatile strategy to signifi cantly enhance the surface properties of polycaprolactone as a paradigm for other synthetic polymers intended for bone-related applications.

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Magdeburg, Univ., Fak. für Naturwiss., Diss., 2011

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Magdeburg, Univ., Fak. für Naturwiss., Diss., 2013

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Within the last few years, several reports have revealed that cell transplantation can be an effective way to replace lost neurons in the central nervous system (CNS) of patients affected with neurodegenerative diseases. Concerning the retina, the concept that newborn photoreceptors can integrate the retina and restore some visual functions was univocally demonstrated recently in the mouse eye (MacLaren et al. 2006) and remains to be achieved in human. These results pave the way to a standard approach in regenerative medicine aiming to replace lost photoreceptors. With the discovery of stem cells a great hope has appeared towards elaborating protocols to generate adequate cells to restore visual function in different retinal degeneration processes. Retinal stem cells (RSCs) are good candidates to repair the retina and are present throughout the retina development, including adulthood. However, neonatal mouse RSCs derived from the radial glia population have a different potential to proliferate and differentiate in comparison to adult RSCs. Moreover, we observed that adult mouse RSCs, depending on the culture conditions, have a marked tendency to transform, whereas neonatal RSCs show subtle chromosome abnormalities only after extensive expansion. These characteristics should help to identify the optimal cell source and culture conditions for cell transplantation studies. These results will be discussed in light of other studies using RSCs as well as embryonic stem cells. Another important factor to consider is the host environment, which plays a crucial role for cell integration and which was poorly studied in the normal and the diseased retina. Nonetheless, important results were recently generated to reconsider cell transplantation strategy. Perspectives to enhance cell integration by manipulating the environment will also be presented.

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Introduction: We previously reported the results of a phase II study for patients with newly diagnosed primary CNS lymphoma (PCNSL) treated with autologous peripheral blood stem-cell transplantation (aPBSCT) and responseadapted whole brain radiotherapy (WBRT). The purpose of this report is to update the initial results and provide long-term data regarding overall survival, prognostic factors, and the risk of treatment-related neurotoxicity.Methods: A long-term follow-up was conducted on surviving primary central nervous system lymphoma patients having been treated according to the ,,OSHO-53 study", which was initiated by the Ostdeutsche Studiengruppe Hamatologie-Onkologie. Between August 1999 and October 2004 twentythree patients with an average age of 55 and median Karnofsky performance score of 70% were enrolled and received high-dose mthotrexate (HD-MTX) on days 1 and 10. In case of at least a partial remission (PR), high-dose busulfan/ thiotepa (HD-BuTT) followed by aPBSCT was performed. Patients without response to induction or without complete remission (CR) after HD-BuTT received WBRT. All patients (n=8), who are alive in 2011, were contacted and Mini Mental State examination (MMSE) and the EORTC QLQ-C30 were performed.Results: Eight patients are still alive with a median follow-up of 116,9 months (79 - 141, range). One of them suffered from a late relapse eight and a half years after initial diagnosis of PCNSL, another one suffers from a gall bladder carcinoma. Both patients are alive, the one with the relapse of PCNSL has finished rescue therapy and is further observed, the one with gall baldder carcinoma is still under therapy. MMSE and QlQ-C30 showed impressive results in the patients, who were not irradiated. Only one of the irradiated patients is still alive with a clear neurologic deficit but acceptable quality of life.Conclusions: Long-term follow-up of our patients, who were included in the OSHO-53 study show an overall survival of 30 percent. If WBRT can be avoided no long-term neurotoxicity has been observed and the patients benefit from excellent Quality of Life. Induction chemotherapy with two cycles of HD-MTX should be intensified to improve the unsatisfactory OAS of 30 percent.

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Autologous stem cell transplantation (ASCT) has been successfully used in HIV-related lymphoma (HIV-Ly) patients on highly active antiretroviral therapy. We report the first comparative analysis between HIV-Ly and a matched cohort of HIV(-) lymphoma patients. This retrospective European Group for Blood and Marrow Transplantation study included 53 patients (66% non-Hodgkin and 34% Hodgkin lymphoma) within each cohort. Both groups were comparable except for the higher proportion of males, mixed-cellularity Hodgkin lymphoma and patients receiving granulocyte colony-stimulating factor before engraftment and a smaller proportion receiving total body irradiation-based conditioning within the HIV-Ly cohort. Incidence of relapse, overall survival, and progression-free survival were similar in both cohorts. A higher nonrelapse mortality within the first year after ASCT was observed in the HIV-Ly group (8% vs 2%), predominantly because of early bacterial infections, although this was not statistically significant and did not influence survival. Thus, within the highly active antiretroviral therapy era, HIV patients should be considered for ASCT according to the same criteria adopted for HIV(-) lymphoma patients.

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ABSTRACT : The epidermis, the outermost compartment of the skin, is a stratified and squamous epithelium that constantly self-renews. Keratinocytes, which represent the main epidermal population, are responsible for its cohesion and barrier function. Epidermal renewal necessitates a fine equilibrium between keratinocyte proliferation and differentiation. The keratinocyte stem cell, located in the basal cell layer, is responsible for epidermal homeostasis and regeneration during the wound healing process. The transcription factor p63 structurally belongs to the p53 superfamily. It is expressed in the basal and supra-basal cell layers of stratified epithelia and is thought to be important for the renewal or the differentiation of keratinocyte stem cells (Yang et al., 1999; Mills et al., 1999). In order to better understand its function, we established an in vitro model of p63 deficient human keratinocyte stem cells using a shp63 mediated RNA interference. Knockdown of endogenous p63 induces downregulation of cell-adhesion genes as previously described (Carroll et al., 2006). Interestingly, the replating of attached p63-knockdown keratinocytes on a feeder layer results in a loss of attachment and proliferation. They are no longer clonogenic. However, if the same population are replated in a fibrin matrix, extended fibrinolysis is reported, a common process in wound healing, suggesting that p63 regulates the fibrinolytic pathway. This result was confirmed by Q-PCR and shows that the urokinase pathway, which mediates fibrinolysis, is upregulated. Altogether, these findings suggest a mechanism in which the fine tuning of p63 expression promotes attachment or release of the keratinocyte stem cell from the basement membrane by inducing genes of adhesion and/or of fibrinolysis. This mechanism may be important for epidermal self-renewal, differentiation as well as wound healing. Its misregulation may be partly responsible for the p63 knockout phenotype. The downregulation of p63 also induces a decrease in LEKTI expression. LEKTI (lymphoepithelial Kazal-type serine protease inhibitor) is a serine protease inhibitor encoded by the Spink5 gene. It is expressed and secreted in the uppermost differentiated layers of stratified epithelia and plays a role in the desquamation process. When this gene is disrupted, humans develop the Netherton syndrome (Chavanas et al., 2000b). It is a dermatosis characterized by hair dysplasias, ichtyosiform erythroderma and impairment in epidermal barrier function promoting inflammation similarly as in psoriasis with inflammatory infiltrate in excess. TNFα (tumor necrosis factor alpha) and EDA1 (ectodysplasin A1) are two transmembraneprecursors that belong to the TNF superfamily, which is involved in immune and inflammation regulation (Smahi et al., 2002). We suggest that the secreted serine protease inhibitor LEKTI plays a role in the regulation of TNFα and EDA1 precursor cleavage and absence of LEKTI induces excess of inflammation. To investigate this hypothesis, we induced downregulation of Spink5 expression in rat keratinocyte stem cells by using a shSpink5 mediated RNA interference approach. Interestingly, expression of TNFα and EDA1 is modified after knockdown of Spink5 by Q-PCR. Moreover, downregulation of Spink5 induces loss of cohesiveness between keratinocytes and colonies adopt a scattered phenotype. Altogether, these preliminary data suggest that downregulation of LEKTI may play a role in the inflammatory response in Netherton syndrome patients, by regulating TNFα expression.

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Objective: To demonstrate the incidence, time course, predisposing factor and reversibility of neurotoxicity in children with brain tumors treated with high dose busulfan-thiotepa with autologous stem cell transplantation (ASCT) and radiation therapy in our institutional experience.Materials and Methods: We performed a retrospective analysis of prospectively collected data. Between May 1988 and May 2007, 110 patients, median age 3.6 years (range, 1 months-15.3 years), with brain tumors were treated with surgical intervention and conventional chemotherapy. All patients received one course of high-dose busulfan-thiotepa with stem cell rescue, followed or preceded by radiotherapy.Results: Twenty-three patients (21%) developed neuroradiological abnormalities on follow-up imaging studies at a median time of 9.2 months (range, 5.6-17.3 months) after day 0 of ASCT. All MRI-lesions appeared in patients receiving radiotherapy after ASCT and were localized inside the 50-55 Gy isodoses. They disappeared in 14 of 23 patients with a median time of 8 months (range, 3-17 months). The presence of MRI-abnormalities was a favorable prognostic factor for overall survival on univariate analysis (hazard ratio: 0.12, 95% confidence interval [0.04, 0.33]), with a 5-year overall survival in patients with MRI-abnormalities of 84% (95% CI, 62-94), comparedto 27% (95% CI, 19-37) in those without lesions. On multivariate analysis, the presence of MRI-abnormalities was an independent prognostic factor for overall survival.Conclusion: MRI-detectable brain abnormalities are common early findings in children treated with high-dose busulfan-thiotepa followed by radiation therapy, and may mimic early tumor recurrence. They are correlated with a better outcome.

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BACKGROUND: Intracoronary injection of autologous bone marrow-derived mononucleated cells (BM-MNC) may improve LV function shortly after acute ST elevation myocardial infarction (STEMI), but little is known about the long-term durability of the treatment effect. METHODS: In a single-centre trial a total of 60 patients with acute anterior STEMI, successful reperfusion therapy and a left ventricular ejection fraction (LVEF) of <50% were screened for the study. 23 patients were actively treated with intracoronary infusion of BM-MNC within a median of 3 days. The open-label control group consisted of 19 patients who did not consent to undergo BM-MNC treatment but agreed to undergo regular clinical and echocardiographic follow-up for up to 5 years after AMI. RESULTS: Whereas at 4 months there was no significant difference between the increase in LVEF in the BM-MNC group and the control group (+7.0%, 95%CI 3.6; 10.4) vs. +3.9%, 95%CI -2.1; 10), the absolute increase at 5 years remained stable in the BM-MNC but not in the control group (+7.95%, 95%CI 3.5; 12.4 vs. -0.5%, 95%CI -5.4; 4.4; p for interaction between groups = 0.035). DISCUSSION: In this single-centre, open-labelled study, intracoronary administration of BM-MNC is feasible and safe in the short term. It is also associated with sustained improvement of left ventricular function in patients with acute myocardial infarction, encouraging phase III studies to examine the potential BM-MNC effect on clinical outcome.

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BACKGROUND: Allogeneic stem cell transplantation is usually considered the only curative treatment option for patients with advanced or transformed myelodysplastic syndromes in complete remission, but post-remission chemotherapy and autologous stem cell transplantation are potential alternatives, especially in patients over 45 years old. DESIGN AND METHODS: We evaluated, after intensive anti-leukemic remission-induction chemotherapy, the impact of the availability of an HLA-identical sibling donor on an intention-to treat basis. Additionally, all patients without a sibling donor in complete remission after the first consolidation course were randomized to either autologous peripheral blood stem cell transplantation or a second consolidation course consisting of high-dose cytarabine. RESULTS: The 4-year survival of the 341 evaluable patients was 28%. After achieving complete remission, the 4-year survival rates of patients under 55 years old with or without a donor were 54% and 41%, respectively, with an adjusted hazard ratio of 0.81 (95% confidence interval [95% CI], 0.49-1.35) for survival and of 0.67 (95% CI, 0.42-1.06) for disease-free survival. In patients with intermediate/high risk cytogenetic abnormalities the hazard ratio in multivariate analysis was 0.58 (99% CI, 0.22-1.50) (P=0.14) for survival and 0.46 (99% CI, 0.22-1.50) for disease-free survival (P=0.03). In contrast, in patients with low risk cytogenetic characteristics the hazard ratio for survival was 1.17 (99% CI, 0.40-3.42) and that for disease-free survival was 1.02 (99% CI, 0.40-2.56). The 4-year survival of the 65 patients randomized to autologous peripheral blood stem cell transplantation or a second consolidation course of high-dose cytarabine was 37% and 27%, respectively. The hazard ratio in multivariate analysis was 1.22 (95% CI, 0.65-2.27) for survival and 1.02 (95% CI, 0.56-1.85) for disease-free survival. CONCLUSIONS: Patients with a donor and candidates for allogeneic stem cell transplantation in first complete remission may have a better disease-free survival than those without a donor in case of myelodysplastic syndromes with intermediate/high-risk cytogenetics. Autologous peripheral blood stem cell transplantation does not provide longer survival than intensive chemotherapy.