70 research outputs found
Neural Potential of a Stem Cell Population in the Hair Follicle
The bulge region of the hair follicle serves as a repository for epithelial stem cells that can regenerate the follicle in each hair growth cycle and contribute to epidermis regeneration upon injury. Here we describe a population of multipotential stem cells in the hair follicle bulge region; these cells can be identified by fluorescence in transgenic nestin-GFP mice. The morphological features of these cells suggest that they maintain close associations with each other and with the surrounding niche. Upon explantation, these cells can give rise to neurosphere-like structures in vitro. When these cells are permitted to differentiate, they produce several cell types, including cells with neuronal, astrocytic, oligodendrocytic, smooth muscle, adipocytic, and other phenotypes. Furthermore, upon implantation into the developing nervous system of chick, these cells generate neuronal cells in vivo. We used transcriptional profiling to assess the relationship between these cells and embryonic and postnatal neural stem cells and to compare them with other stem cell populations of the bulge. Our results show that nestin-expressing cells in the bulge region of the hair follicle have stem cell-like properties, are multipotent, and can effectively generate cells of neural lineage in vitro and in vivo
Magnetic resonance spectroscopy identifies neural progenitor cells in the live human brain
The identification of neural stem and progenitor cells (NPCs) by in vivo brain imaging could have important implications for diagnostic, prognostic, and therapeutic purposes. We describe a metabolic biomarker for the detection and quantification of NPCs in the human brain in vivo. We used proton nuclear magnetic resonance spectroscopy to identify and characterize a biomarker in which NPCs are enriched and demonstrated its use as a reference for monitoring neurogenesis. To detect low concentrations of NPCs in vivo, we developed a signal processing method that enabled the use of magnetic resonance spectroscopy for the analysis of the NPC biomarker in both the rodent brain and the hippocampus of live humans. Our findings thus open the possibility of investigating the role of NPCs and neurogenesis in a wide variety of human brain disorders
Biofabrication for neural tissue engineering applications
Unlike other tissue types, the nervous tissue extends to a wide and complex
environment that provides a plurality of different biochemical and topological
stimuli which in turn define the functions of that tissue. As a consequence of
such complexity, the traditional transplantation therapeutic methods are quite
ineffective; therefore, the restoration of peripheral and central nervous
system injuries has been a continuous challenge. Tissue engineering and
regenerative medicine in the nervous system have provided new alternative
medical approaches. These methods use external biomaterial supports, known as
scaffolds, in order to create platforms for the cells to migrate to the injury
site and repair the tissue. The challenge in neural tissue engineering (NTE)
remains the fabrication of scaffolds with precisely controlled, tunable
topography, biochemical cues and surface energy, capable of directing and
controlling the function of neuronal cells. At the same time, it has been shown
that neural tissue engineering provides the potential to model neurological
diseases in vitro, mainly via lab-on-a-chip systems, especially in cases for
which it is difficult to obtain suitable animal models. As a consequence of the
intense research activity in the field, a variety of synthetic approaches and
3D fabrication methods have been developed for the fabrication of NTE
scaffolds, including soft lithography and self-assembly, as well as subtractive
(top-down) and additive (bottom-up) manufacturing. This article aims at
reviewing the existing research effort in the rapidly growing field related to
the development of biomaterial scaffolds and lab-on-a-chip systems for NTE
applications. Besides presenting recent advances achieved by NTE strategies,
this work also delineates existing limitations and highlights emerging
possibilities and future prospects in this field
Nitric oxide and multiple sclerosis
Nitric oxide (NO) is a free radical signaling molecule with remarkably complex biochemistry. Its involvement in multiple sclerosis (MS) had been postulated soon after the discovery of the critical role NO plays in inflammation. However, the extent of NO's contribution to MS is not yet understood, party due to the often opposing roles that NO can play in cellular processes. This review briefly covers new developments in the area of NO that may be relevant to MS. It also describes recent progress in understanding the role of NO in MS, new potential targets of the action of NO in the cell, and prospects for NO-based therapies
JUST in time health emergency interventions: an innovative approach to training the citizen for emergency situations using virtual reality techniques and advanced IT tools
Ausloos Hans. Wolfgang Kraus, Martin Karrer (éds), Die Septuaginta – Texte, Theologien, Einflüsse (coll. Wissenschaftliche Untersuchungen zum Neuen Testament, 252), 2010. In: Revue théologique de Louvain, 42ᵉ année, fasc. 2, 2011. pp. 281-282
The role of delayed aortic surgery in type A aortic dissection and mesenteric ischemia: a systematic review and meta-analysis
Abstract Introduction Approximately one third of patients with Acute Type A Aortic Dissection (ATAAD) present with pre-operative malperfusion syndromes (MPS). Of these, mesenteric malperfusion represents the greatest risk to patients with respect to increased short-term mortality. In select patients, it may be feasible to offer a staged approach by treating the mesenteric malperfusion first, optimizing the patient in the intensive care setting and then, following with a central aortic repair. The aim of this systematic review is to summarize cohort studies assessing the role of pre-operative interventions for mesenteric malperfusion. Methods An electronic literature search of five databases was performed to identify all relevant studies providing studies examining short-term mortality on patients who underwent either endovascular or open revascularisation of mesenteric ischemia prior to central aortic repair. The primary outcome was all-cause, short-term mortality. Secondary outcomes were comparative mortality between a delayed repair vs. aortic repair first strategy, rates of postoperative laparotomy, bowel resection, and mortality following delayed aortic repair. Results The search strategy identified 8 studies qualifying for inclusion, with a total of 180 patients who underwent delayed aortic surgery in the setting of mesenteric MPS. The weighted short-term mortality following a mesenteric revascularisation first, delayed aortic surgery strategy was 22.5%. This strategy was also associated with a significantly lower mortality than a central repair first strategy (OR 0.07, 95% CI 0.02–0.27), and a significantly lower rate of postoperative laparotomy/bowel resection (OR 0.05, 95% CI 0.02–0.14). If patients survive to receive central repair, the weighted short-term mortality postoperatively is low (2.1%). Conclusion A summary of this evidence reveals a lower short-term mortality in hemodynamically stable patients with mesenteric malperfusion, along with a reduction in postoperative laparotomy/bowel resections. Of those patients who survive to receive central repair, short-term mortality remains very low in the select group of hemodynamically stable patients. Further high-quality studies with randomized or propensity matched data are required to verify these results
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