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1.
For many years, accepted dogma held that brain is a static organ with no possibility of regeneration of cells in injured or diseased human brain. However, recent preclinical reports have shown regenerative potential of neural stem cells using various injury models. This has resulted in renewed hope for those suffering from spinal cord injury and neural damage. As the potential of stem cell therapy gained impact, these claims, in particular, led to widespread enthusiasm that acute and chronic injury of the nervous system would soon be a problem of the past. The devastation caused by injury or diseases of the brain and spinal cord led to wide premature acceptance that “neural stem cells (NSCs)” derived from embryonic, fetal or adult sources would soon be effective in reversing neural and spinal trauma. However, neural therapy with stem cells has not been realized to its fullest extent. Although, discrete population of regenerative stem cells seems to be present in specific areas of human brain, the function of these cells is unclear. However, similar cells in animals seem to play important role in postnatal growth as well as recovery of neural tissue from injury, anoxia, or disease. J. Cell. Biochem. 114: 764–772, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
2.
Generally accepted methods of single-cell microsurgery in terms of their compliance with the task of preserving cell integrity and minimizing possible damage in various microsurgery manipulations on embryos and somatic cells, namely, during microsurgical transfer of nuclei for cloning, production of monozygotic twins, and microinjections into the cell, are analyzed in detail. The problems regarding the cell contacts with microtools, perforation as a factor of cell damage (when a microtool penetrates a cell), the influence of light on the cell, and retention of the cell during microsurgery (and the resulting effect of negative pressure on the cell) are discussed. The question of how long a single cell can persist in a microchamber in vitro is considered, as well as the impact of mineral oil used as a barrier against solvent evaporation. The effect of the physicochemical composition of the glass that is used for microtools is addressed for the first time, as well as the impact of thermal shock and fresh culture medium on a living cell. 相似文献
7.
I have attempted to summarize the progress that has been made in organ transplantation in the past 50 years since the first identical twin transplant. For those who have worked long in this area its success has been remarkable. We currently expect patients to survive the operation and more than 90% of the graft to be functioning at a year with the half-life of the graft beyond 10 years, with some patients surviving into the fifth decade after kidney transplantation with grafts from unrelated donors and the fourth decade for liver transplants. Now the main stumbling block is shortage of organ donors and this is unlikely to be solved easily. There has been a considerable increase in donations from living volunteers and also the worry of immoral and illegal practices.In the future, we can expect considerable advances in immunosuppression with more effective, less toxic drugs and in some patients induction therapy that may approach tolerance so that no maintenance therapy will eventually be needed. Cell transplantation is likely to be developed as treatment for the clinic in the next 5-10 years, but developments of transplantation from animal to man still remains unsolved and unlikely to be successful in the clinic in the near future. 相似文献
8.
Electrophysiological experiments were performed on pituitary cells grown in culture. Two types of cells were studied, one of tumoral origin (GH3-B6; GH4-C1; human adenoma) and another type isolated from normal male and female rat pituitaries. Intracellular recordings showed that these cells displayed action potentials which were blocked by calcium antagonists (cobalt, manganese, cadmium, methoxyverapamil). The electrical activity of the cells was affected by substances known to modify hormone release. Dopamine and γ-aminobutyric acid inhibited action potential discharge of GH3 and prolactin-secreting cells, whereas thyreoliberin and estrogen led to an increase of the electrical activity of GH3, acromegalic and “non-functioning” tumor cells. Patch clamp experiments on clonal growth hormone-secreting cells make it possible to record specific ionic currents (e.g. calcium current), through the total membrane of the cell, in adequate voltage clamp conditions. Increase of the calcium current was observed after addition of growth hormone releasing factor, somatocrinin. It was also possible to observe the behaviour of individual ionic channels. We may conclude from intracellular and patch clamp recordings that modulation of the membrane electrical activity may alter the amount of cytosolic calcium and consequently may control hormone release in endocrine cells. 相似文献
10.
Filamentous fungi are important organisms industrially and continue to attract research interest as microbiologists attempt to overcome the problems associated with their behavior in submerged culture. This review critically examines the literature describing these problems and where available suggests possible solutions to them. The influence of the chemical and physical environment on culture morphology, the process engineering challenges presented by different fungal morphologies, and the relationship between fungal morphology and metabolite production are all discussed. 相似文献
11.
Three monoclonal antibodies (MAbs) specifically recognizing rat astrocyte cell surface proteins have been characterized and their antigen binding specificities determined. One of these MAbs has been employed to isolate a distinct subpopulation of astroglial cells using immunoaffinity chromatography. MAbs to rat astroglial cell surface proteins, generated by fusion of mouse Sp2/O-Ag 14 myeloma cells and spleen cells from Balb/C mice immunized with purified astroglial cells, were screened for their cell binding specificities using ELISA and indirect immunofluorescence assay. The antigen binding specificity of three of these clones, which displayed specific binding to astrocytes, was determined by radioiodination of whole astrocytes and precipitation of the iodinated surface proteins by the MAbs. Immunoaffinity chromatography, using IgG from one of the clones coupled to CNBr activated Sepharose 6MB, demonstrated the potential usefulness of such MAbs in isolating a specific subpopulation of astroglial cells. 相似文献
12.
Heart diseases are a leading cause of morbidity and mortality. Cardiac stem cells (CSC) are considered as candidates for cardiac‐directed cell therapies. However, clinical translation is hampered since their isolation and expansion is complex. We describe a population of human cardiac derived adherent proliferating (CAP) cells that can be reliably and efficiently isolated and expanded from endomyocardial biopsies (0.1 cm 3). Growth kinetics revealed a mean cell doubling time of 49.9 h and a high number of 2.54 × 10 7 cells in passage 3. Microarray analysis directed at investigating the gene expression profile of human CAP cells demonstrated the absence of the hematopoietic cell markers CD34 and CD45, and of CD90, which is expressed on mesenchymal stem cells (MSC) and fibroblasts. These data were confirmed by flow cytometry analysis. CAP cells could not be differentiated into adipocytes, osteoblasts, chondrocytes, or myoblasts, demonstrating the absence of multilineage potential. Moreover, despite the expression of heart muscle markers like α‐sarcomeric actin and cardiac myosin, CAP cells cannot be differentiated into cardiomyocytes. Regarding functionality, CAP cells were especially positive for many genes involved in angiogenesis like angiopoietin‐1, VEGF, KDR, and neuropilins. Globally, principal component and hierarchical clustering analysis and comparison with microarray data from many undifferentiated and differentiated reference cell types, revealed a unique identity of CAP cells. In conclusion, we have identified a unique cardiac tissue derived cell type that can be isolated and expanded from endomyocardial biopsies and which presents a potential cell source for cardiac repair. Results indicate that these cells rather support angiogenesis than cardiomyocyte differentiation. J. Cell. Biochem. 109: 564–575, 2010. © 2009 Wiley‐Liss, Inc. 相似文献
14.
Information will have an increasing impact on biotechnology. A co-ordinated European programme is required now to provide resources and services such as databanks and advanced computers to make a full contribution to efforts undertaken internationally. 相似文献
16.
Transforming growth factor type-e (TGFe) is a novel TGF which was first described as a growth factor possibly involved in autocrine stimulation of anchorage-independent growth of carcinoma cells. Its later identification in normal tissues, plasma, and platelets suggested a role for TGFe in normal cell growth. This study shows that TGFe stimulates both anchorage-dependent and -independent growth of epithelial and fibroblastic cells of nonneoplastic origin. The mitogenic activity of TGFe in monolayer is slightly less than that of basic fibroblast growth factor, equipotent to that of epidermal growth factor, and greater than that of IGF-1. TGFe acts as a progression factor for both AKR-2B and Balb-3T3 cells. TGFe is also a potent mitogen for normal human epidermal keratinocytes and may therefore play a role in epidermal growth and regeneration. 相似文献
18.
There are fewer than 162 ha of commercial Chinese chestnut orchards in the United States, with approximately half of these in the Southeast. Large numbers of Chinese chestnut seedlings are planted annually in the United States for home and game food production; however, knowledge about chestnut propagation, fertilization, pests, harvest, storage and marketing is not adequate. There is little commercial marketing of U.S.-grown Chinese chestnuts through roadside markets and local farmers’ markets as the supply is low and unpredictable. However, we yearly import 4.5 mill kg of European chestnuts to satisfy the U.S. market. Successful chestnut orchards will require vegetatively propagated selections, intensive management, mechanical harvesting, and control of insect and disease pests. 相似文献
20.
Mitochondria are central not only to the bioenergetics of the cell but also to the process of apoptotic cell death. Substantial data indicate mitochondrial dysfunction, particularly of complex I of the electron transport chain, in some patients with Parkinson's disease (PD), and it appears likely that mitochondria contribute to the pathogenic processes that occurs in this disorder. Treatments targeted at mitochondrial function hold promise to slow the progression of PD. 相似文献
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