334 research outputs found

    Another win for endothelial progenitor cells: Endothelial progenitor cell-derived conditioned medium promotes proliferation and exerts neuroprotection in cultured neuronal progenitor cells.

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    Progress in stem cell research demonstrates stem cells' potential for treating neurodegenerative diseases. Stem cells have proliferative/differentiative properties and produce a variety of paracrine factors that can potentially be used to regenerate nervous tissue. Previous studies have shown the positive regenerative effects of endothelial progenitor cells (EPCs), and thus, they may be used as a tool for regeneration. A study by Di Santo et al. explored whether EPC-derived conditioned medium (EPC-CM) promotes the survival of cultured striatal progenitor cells and attempted to find the paracrine factors and signaling pathways involved with EPC-CM's effects. The neuronal progenitor cells that were cultured with EPC-CM had much higher densities of GABA-immunoreactive (GABA-ir) neurons. It was shown that phosphatidylinositol-3-kinase/AKT and mitogen-activated protein kinase/ERK signaling pathways are involved in the proliferation of GABAergic neurons, as inhibition of these pathways decreased GABAergic densities. In addition, the results suggest that paracrine factors from EPC, both proteinaceous and lipidic, significantly elevated the viability and/or differentiation in the cultures. Importantly, it was found that EPC-CM provided neuroprotection against toxins from 3-nitropropionic acid. In sum, EPC-CM engendered proliferation and regeneration of the cultured striatal cells through paracrine factors and imparted neuroprotection. Furthermore, the effects of EPC-CM may generate a cell-free therapeutic strategy to address neurodegeneration

    Endothelial Progenitor Cell-Derived Factors Exert Neuroprotection in Cultured Cortical Neuronal Progenitor Cells.

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    There is substantial evidence that stem and progenitor cells secrete trophic factors that have potential for repairing injured tissues. We have previously reported that the conditioned medium (CM) obtained from endothelial progenitor cells (EPC) cultures protects striatal neurons against 3-nitropropionic acid-induced toxicity. In the present study we tested the hypothesis that EPC-CM may support cortical neuronal cell function and/or survival. EPC were isolated from the peripheral blood of healthy human donors and cultured in hypoxic conditions (1.5% O2) to stimulate the secretion of growth factors. The supernatant or conditioned medium (EPC-CM) was then collected and used for the various experiments. Primary cultures of cerebral cortex from fetal rat embryonic day 14 were treated with EPC-CM and challenged by glucose and serum deprivation. We observed that EPC-CM treatment significantly increased total cell number and cell viability in the cultures. Similarly, the number of lba1-expressing cells was significantly upregulated by EPC-CM, while western blot analyses for the astroglial marker glial fibrillary acidic protein did not show a marked difference. Importantly, the number of beta-lll-tubulin-positive neurons in the cultures was significantly augmented after EPC-CM treatment. Similarly, western blot analyses for beta-III-tubulin showed significant higher signal intensities. Furthermore, EPC-CM administration protected neurons against glucose- and serum deprivation-induced cell loss. In sum, our findings identified EPC-CM as a means to promote viability and/or differentiation of cortical neurons and suggest that EPC-CM might be useful for neurorestorative approaches

    A comparative evaluation of intrathoracic latissimus dorsi and serratus anterior muscle transposition

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    Background: Comparison of intrathoracic latissimus dorsi (LD) versus serratus anterior (SA) muscle transposition for treatment of infected spaces, broncho-pleural fistulae, and for prophylactic reinforcement of the mediastinum after extended resections following induction therapy. Patients and methods: Twenty LD and 17 SA transfers were performed for prophylactic reinforcement (11 LD; nine SA), and treatment of infections (nine LD; eight SA) from 1995 to 1998. Results: The 30-day mortality was 0% following prophylactic reinforcement and 29% following treatment of infections (three LD; two SA). Prophylactic mediastinal reinforcement was successful in 11 of 11 patients with LD and nine of nine with SA transpositions, and treatment of infected spaces in eight of nine patients with LD and two of three with SA transfers. Morbidity requiring re-intervention consisted of flap necrosis (one LD), bleeding (one SA), and skin necrosis over a winged scapula (one SA). Subcutaneous seromas and chest wall complaints were more frequent following LD (45 and 36%, respectively) compared with SA transfers (29 and 27%, respectively), whereas impaired shoulder girdle function was more frequent after SA than after LD transfer (27 vs. 21%). Conclusion: Intrathoracic LD and SA muscle transpositions are both efficient for the prevention or control of infections following complex thoracic surgery, and are both associated with similar and acceptable morbidity and long-term sequela

    Endovascular and surgical treatment of spinal dural arteriovenous fistulas

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    Introduction: The aim of this retrospective study was to evaluate the clinical outcome of patients with spinal dural arteriovenous fistulas (SDAVFs) that were treated with surgery, catheter embolization, or surgery after incomplete embolization. Methods: The study included 21 consecutive patients with SDAVFs of the thoracic, lumbar, or sacral spine who were treated in our institution from 1994 to 2007. Thirteen patients were treated with catheter embolization alone. Four patients underwent hemilaminectomy and intradural interruption of the fistula. Four patients were treated by endovascular techniques followed by surgery. The clinical outcome was assessed using the modified Aminoff-Logue scale (ALS) for myelopathy and the modified Rankin scale (MRS) for general quality of life. Patient age ranged from 44 to 77years (mean 64.7years). Results: Surgical as well as endovascular treatment resulted in a significant improvement in ALS (−62.5% and −31.4%, respectively, p < 0.05) and a tendency toward improved MRS (−50% and −32%, respectively) scores. Patients that underwent surgery after endovascular treatment due to incomplete occlusion of the fistula showed only a tendency for improvement in the ALS score (−16.7%), whereas the MRS score was not affected. Conclusion: We conclude that both endovascular and surgical treatment of SDAVFs resulted in a good and lasting clinical outcome in the majority of cases. In specific situations, when a secondary neurosurgical approach was required after endovascular treatment to achieve complete occlusion of the SDAVF, the clinical outcome was rather poor. The best first line treatment modality for each individual patient should be determined by an interdisciplinary tea

    Miniaturization of Chemical Analysis Systems – A Look into Next Century's Technology or Just a Fashionable Craze?

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    Miniaturization of already existing techniques in on-line analytical chemistry is an alternative to compound-selective chemical sensors. Theory points in the direction of higher efficiency, faster analysis time, and lower reagent consumption. Micromachining, a well known photolithographic technique for structures in the micrometer range, is introduced and documented with structures as examples for flow injection analysis, electrophoresis, and a detector cell

    Persistent bone impairment despite long-term control of hyperprolactinemia and hypogonadism in men and women with prolactinomas.

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    While prolactinoma patients have high bone turnover, current data are inconclusive when it comes to determining whether correction of hyperprolactinemia and associated hypogandism improves osteodensitometric data in men and women over the long term. In a large cohort of including 40 men and 60 women, we studied the long-term impact of prolactinoma treatment on bone mineral density (BMD) in men versus women, assessed adverse effects of a primary surgical or medical approach, and evaluated data for risk factors for impaired BMD at last follow-up using multivariate regression analyses. Median duration of follow-up was 79 months (range 13-408 months). Our data indicate that the prevalence of impaired BMD remained significantly higher in men (37%) than in women (7%, p < 0.001), despite the fact that hyperprolactinemia and hypogonadism are under control in the majority of men. We found that persistent hyperprolactinemia and male sex were independent risk factors for long-term bone impairment. Currently, osteoporosis prevention and treatment focus primarily on women, yet special attention to bone loss in men with prolactinomas is advised. Bone impairment as "end organ" reflects the full range of the disease and could become a surrogate marker for the severity of long-lasting hyperprolactinemia and associated hypogonadism
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