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1.
Zentralbl Gynakol ; 127(6): 368-72, 2005 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-16341979

RESUMO

Adult stem cells from umbilical cord and cord blood are an interesting alternative to embryonic stem cells because such research is commonly recognized as ethical undisputed and many aspects are still insufficiently investigated. In the context of the STEMMAT research project (STEM = Stem Cell and MAT = Material) different aspects of stem cells from umbilical cord and cord blood are investigated, to improve basic science understanding and potentially leading someday to a clinical application.


Assuntos
Ética em Pesquisa , Sangue Fetal/citologia , Transplante de Células-Tronco de Sangue do Cordão Umbilical/ética , Feminino , Humanos , Gravidez , Pesquisa/normas , Doadores de Tecidos
2.
Chirurg ; 76(5): 435-44, 2005 May.
Artigo em Alemão | MEDLINE | ID: mdl-15856142

RESUMO

Postnatal stem cells play a decisive role in cell-based therapies due to their high proliferation activity and functional plasticity. On the one hand, basic research in cell biological processes of adult stem cells is crucial in order to establish them as therapeutic tools. On the other hand, development and enhancements of appropriate techniques are required: we need to establish defined technologies for extraction and differentiation of stem cells and to develop adequate cell carrier devices, scaffolds, and bioreactors for in vitro purposes. Furthermore, it is an interdisciplinary challenge to consider logistical aspects concerning isolation, transport, and storage of stem cells in order to use them in a wide range of activities in regenerative medicine. In this review we present the current methods of work and research on adult stem cells. We explain their therapeutic use and define requirements for future technological developments for work with postnatal stem cells.


Assuntos
Regeneração/fisiologia , Transplante de Células-Tronco/instrumentação , Engenharia Tecidual/instrumentação , Transplantes , Reatores Biológicos , Técnicas de Cultura de Células/instrumentação , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Separação Celular/instrumentação , Sistemas de Gerenciamento de Base de Dados , Desenho de Equipamento , Transplante de Células-Tronco Hematopoéticas/instrumentação , Humanos , Transplantes/tendências
3.
Orthopade ; 33(12): 1338-45, 2004 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-15455199

RESUMO

The identification of appropriate cell types is necessary to establish cell-based therapies in regenerative medicine. These cell types must (1) be available in an appropriate amount, (2) be easy to obtain, (3) be sufficiently expandable in vitro, and (4) fit to or at least be able to differentiate into the required cell type. Since the umbilical cord is available without any intervention and represents a notable amount of tissue, we consider it to be a promising source for isolating cells for cell-based therapies. This study demonstrates that umbilical cord stromal cells (UCSC), the connective tissue cells of the umbilical cord, can be isolated in sufficient quantities and be well expanded. UCSC feature phenotypic plasticity and thus are functionally similar to stem cells. UCSC can be differentiated into cells with osteoblastic properties (expression of alkaline phosphatase, formation of bone nodules). It is concluded that the umbilical cord should no longer be regarded as valueless tissue and be unthinkingly discarded. Instead, it should be considered a valuable resource for the isolation of potent cells for cell-based therapies, especially for treatment of bone defects.


Assuntos
Diferenciação Celular/fisiologia , Osteoblastos/citologia , Osteogênese/fisiologia , Células Estromais/citologia , Engenharia Tecidual/métodos , Cordão Umbilical/citologia , Fosfatase Alcalina , Animais , Regeneração Óssea/fisiologia , Separação Celular/métodos , Humanos , Microscopia de Fluorescência
4.
Artigo em Alemão | MEDLINE | ID: mdl-12704901

RESUMO

Progress in the surgery of implants and biomaterials can be accomplished by: 1. Painstakingly analysing and registering of defaulting implants after explantation within a "National Registry of Implant Pathology". 2. Development of a DNA-microarray named "Implantat/Chronic Wound" in order to discover the differential transcriptional activities of cells brought into contact with different foreign surfaces. 3. Predictive cell-engineering combined with custom-made implant surfaces with the aim of optimal patient care.


Assuntos
Análise de Falha de Equipamento/métodos , Reação a Corpo Estranho/patologia , Teste de Materiais/métodos , Complicações Pós-Operatórias/patologia , Células Cultivadas/patologia , Células Gigantes/patologia , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Desenho de Prótese , Sistema de Registros
5.
J Mater Sci Mater Med ; 12(2): 97-106, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15348314

RESUMO

The functioning of an implant depends on the material properties and the wound-healing process. The latter is led by an inflammatory reaction guided mainly by monocyte/macrophage activity. This in vitro study investigated human monocytes/macrophages in culture from 2 h to 10 days on silicone, polyurethane, teflon and TCPS. Analysis of cytokine release by ELISA showed that maturing macrophages have different capacities to produce cytokines TNFalpha, IL10, IL8 and GM-CSF. The long culture-mature macrophages on all polymers produced comparable low levels of TNFalpha, IL10 and IL8. Monocytes/macrophages on polyurethane and teflon, and those on silicone only in long culture-time produced high GM-CSF amounts, where as those on TCPS exhibited low levels of GM-CSF. FACS analysis revealed that HSP70i was highly inducible after short time culture yet this high level was maintained in long culture-mature macrophages on TCPS only, whereas on other polymers the mature macrophages showed a high reduction in HSP70i level, which demonstrated a high stress-response by cells on TCPS. Accordingly, CLSM-analysis revealed low nuclear NF-kappaB in cells on TCPS and high nuclear NF-kappaB in mature macrophages on silicone and polyurethane, showing a high cellular activation on the latter two polymers. This corresponded also to the high mitochondrial activity by XTT metabolism displayed by the mature macrophages on polyurethane >/= silicone > teflon > TCPS. These data show a correlation of (1) cytokines (TNFalpha, GM-CSF) and HSP70i, (2) NF-kappaB and HSP70i by monocytes/macrophages after contact with polymers. Thus, HSP70i might be a useful molecular candidate for exploring biomaterial-induced inflammatory reaction.

6.
APMIS ; 109(9): 601-6, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11878713

RESUMO

AIMS: Cytogenetic data on solitary fibrous tumours (SFT) are very limited. We studied a benign pleural SFT for its ultrastructural and immunohistochemical details, and made cytogenetic analyses for comparison with other genetic and ultrastructural studies of SFT. RESULTS: Immunohistochemistry showed strong positivities for CD34 and vimentin, but no reactions with anti-cytokeratins and epithelial membrane antigens. Electron microscopy revealed primitive desmosomes in our SFT. The results thus evinced fibroblast-like cells with intermediate epithelial-mesenchymal character. Comparative genomic hybridization of the tumour revealed losses of 1p33-->pter, 17pter q21, entire copies of chromosomes 19 and 22, and gains of 1p21-p22, 2q23-q32.3, 3pl2-q13.2, 4p14-q28, 6p12-q21, 9p21-->pter and 13q21-q31. Furthermore, there was loss of 20q, as was previously reported elsewhere in a case of benign and a case of malignant SFT. CONCLUSIONS: The results furnish further evidence of the involvement of -20q in SFT. In addition, they show that SFT may have complex genomic imbalances and primitive features, despite having a benign appearance.


Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 20/genética , Neoplasias de Tecido Fibroso/genética , Neoplasias Pleurais/genética , Desmossomos/ultraestrutura , Epitélio , Feminino , Humanos , Cariotipagem , Pessoa de Meia-Idade , Neoplasias de Tecido Fibroso/patologia , Neoplasias Pleurais/patologia
8.
Biochem J ; 321 ( Pt 3): 629-38, 1997 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9032447

RESUMO

Alternative substrates of energy metabolism are thought to contribute to the impairment of heart and muscle glucose utilization in insulin-resistant states. We have investigated the acute effects of substrates in isolated rat cardiomyocytes. Exposure to lactate, pyruvate, propionate, acetate, palmitate, beta-hydroxybutyrate or alpha-oxoglutarate led to the depression of glucose transport by up to 50%, with lactate, pyruvate and propionate being the most potent agents. The percentage inhibition was greater in cardiomyocytes in which glucose transport was stimulated with the alpha-adrenergic agonist phenylephrine or with a submaximal insulin concentration than in basal or fully insulin-stimulated cells. Cardiomyocytes from fasted or diabetic rats displayed a similar sensitivity to substrates as did cells from control animals. On the other hand, the amination product of pyruvate (alanine), as well as valine and the aminotransferase inhibitors cycloserine and amino-oxyacetate, stimulated glucose transport about 2-fold. In addition, the effect of pyruvate was counteracted by cycloserine. Since reversible transamination reactions are known to affect the pool size of the citrate cycle, the influence of substrates, amino acids and aminotransferase inhibitors on citrate, malate and glutamate content was examined. A significant negative correlation was found between alterations in glucose transport and the levels of citrate (P < 0.01) or malate (P < 0.01), and there was a positive correlation between glucose transport and glutamate levels (P < 0.05). In contrast, there was no correlation with changes in [1-(14)C]pyruvate oxidation or in glucose-6-phosphate levels. Finally, pyruvate decreased the abundance of GLUT4 glucose transporters at the surface of phenylephrine- or insulin-stimulated cells by 34% and 27 % respectively, as determined by using the selective photoaffinity label [3H]ATB-BMPA [[3H]2-N-[4-(1-azi-2,2,2-trifluoroethyl)benzoyl]-1,3-bis-(D-man nos-4-yloxy)propyl-2-amine]. In conclusion, cardiomyocyte glucose transport is subject to counter-regulation by alternative substrates. The glucose transport system appears to be controlled by (a) compound(s) of intermediary metabolism (other than glucose 6-phosphate), but in a different way than pyruvate dehydrogenase. Transport inhibition eventually occurs via a decrease in the amount of glucose transporters in the plasma membrane.


Assuntos
Glucose/metabolismo , Proteínas de Transporte de Monossacarídeos/metabolismo , Proteínas Musculares , Miocárdio/metabolismo , Ácido 3-Hidroxibutírico , 3-O-Metilglucose/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Células Cultivadas , Desoxiglucose/metabolismo , Diabetes Mellitus Experimental , Metabolismo Energético/fisiologia , Inibidores Enzimáticos/farmacologia , Transportador de Glucose Tipo 1 , Transportador de Glucose Tipo 4 , Hidroxibutiratos/farmacologia , Insulina/farmacologia , Ácido Láctico/farmacologia , Fenilefrina/farmacologia , Ácido Pirúvico/metabolismo , Ácido Pirúvico/farmacologia , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Especificidade por Substrato , Transaminases/antagonistas & inibidores , Transaminases/metabolismo
9.
Life Sci ; 59(2): 141-51, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8699921

RESUMO

The action of anoxia on glucose transport was investigated in isolated resting rat cardiomyocytes. Incubation of these cells in the absence of oxygen for 30 min resulted in a 4- to 5-fold increase in glucose transport (with a lag period of 5-10 min). Up to 40 min of anoxia failed to alter the cellular concentrations of ATP, phosphocreatine, and creatine. Adenosine deaminase (1.5 U/ml), the A1-adenosine receptor antagonist 1,3-diethyl-8-phenylxanthine (1 microM), or the A2-selective antagonist 3,7-dimethyl-1-propargylxanthine (20 microM) had no effect on anoxia-dependent glucose transport. Moreover, adenosine (10-300 microM, added under normoxia) did not stimulate glucose transport. Wortmannin (1 microM) did not influence the effect of anoxia, but completely suppressed that of insulin. On the other hand, the effects of anoxia and insulin were not additive. These results indicate (i) that the effect of anoxia on cardiomyocyte glucose transport is not mediated by a change in energy metabolism, nor by an adenosine release; (ii) that it probably does not involve a phosphatidylinositol 3-kinase, in contrast to the effect of insulin, and (iii) that the signal chains triggered by anoxia or insulin may converge downstream of this enzyme, or, alternatively, that anoxic conditions may impair the action of the hormone.


Assuntos
Adenosina/metabolismo , Glucose/metabolismo , Hipóxia/metabolismo , Miocárdio/metabolismo , Animais , Metabolismo Energético , Insulina/farmacologia , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
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