1,147 research outputs found
Regeneration potential and survival of transplanted undifferentiated adipose tissue-derived stem cells in peripheral nerve conduits
No full textAdipose tissue-derived stem cells (ADSCs) have shown potential for the treatment of nerve injuries. Most previous efforts have aimed at stimulating regeneration by using neural-differentiation protocols, but the potential of undifferentiated ADSCs to enhance axonal growth as well as their ability to transdifferentiate in situ have been poorly investigated. In this study, using a rat sciatic nerve model we show that ADSCs, transplanted in an artificial nerve conduit, stimulate axonal outgrowth from the proximal nerve stump and evoke greater Schwann cell (SC) proliferation/intrusion in the distal stump. To track the fate of the transplanted cells, we used green fluorescent protein (GFP)-labelling and polymerase chain reaction (PCR) for the detection of the sex determining region Y (SRY) gene in the donor male cells. Both methods indicated a lack of significant quantities of viable cells 14 days after transplantation. These results suggest that any regenerative effect of transplanted ADSCs is more likely to be mediated by an initial boost of released growth factors and/or by an indirect effect on endogenous SCs activity. Future studies need to address long-term cell survival in tissue-engineered nerve conduits to improve the neuroregenerative potential of ADSCs
Fibrin matrix for suspension of regenerative cells in an artificial nerve conduit
No full textPeripheral nerve injury presents with specific problems of neuronal reconstructions, and from a clinical viewpoint a tissue engineering approach would facilitate the process of repair and regeneration. We have previously used artificial nerve conduits made from bioresorbable poly-3-hydroxybutyrate (PHB) in order to refine the ways in which peripheral nerves are repaired and reconnected to the target muscles and skin. The addition of Schwann cells (SC) or differentiated mesenchymal stem cells (dMSC) to the conduits enhances regeneration. In this study, we have used a matrix based on fibrin (Tisseel) to fill optimally the nerve-conduits with cells. In vitro analysis showed that both SC and MSC adhered significantly better to PHB in the presence of fibrin and cells continued to maintain their differentiated state. Cells were more optimally distributed throughout the conduit when seeded in fibrin than by delivery in growth medium alone. Transplantation of the nerve conduits in vivo showed that cells in combination with fibrin matrix significantly increased nerve regeneration distance (using PGP9.5 and S100 distal and proximal immunohistochemistry) when compared with empty PHB conduits. This study shows the beneficial combinatory effect of an optimised matrix, cells and conduit material as a step towards bridging nerve gaps which should ultimately lead to improved functional recovery following nerve injury
Donor site morbidity of the posterior conchal region
No full textBACKGROUND: The perichondral cutaneous graft (PCCG) from the posterior conchal region is an elegant solution for the coverage of facial defects with particular stability requirements. The donor defect can easily be covered with a transposition flap from the postauricular region. Although this region is a common donor site for skin grafts and has an important supporting function for glasses or hearing aids, little is known about long-term morbidity after graft harvest. OBJECTIVE: To assess the morbidity of the posterior concha and the postauricular region in terms of pain, scar formation, and patient satisfaction. MATERIALS AND METHODS: A retrospective study of 16 patients who had a PCCG harvested from the posterior concha. RESULTS: Two patients presented with a postoperative wound dehiscence on the postauricular region and one with a keloid scar on the posterior concha. One case of transitory hyperesthesia and pain when sleeping on the operated site was observed. None had complaints related to wearing glasses or hearing aids. CONCLUSION: Donor site morbidity of the postauricular and posterior conchal region is minimal and associated with high patient satisfaction, excellent aesthetic results, and emotional detachment from the hidden donor site
Validity and reliability of the CatWalk system as a static and dynamic gait analysis tool for the assessment of functional nerve recovery in small animal models
No full textIntroduction: A range of behavioral testing paradigms have been developed for the research of central and peripheral nerve injuries with the help of small animal models. Following any nerve repair strategy, improved functional outcome may be the most important evidence of axon regeneration. A novel automated gait analysis system, the CatWalkTM, can measure dynamic as well as static gait patterns of small animals. Of most interest in detecting functional recovery are in particular dynamic gait parameters, coordination measures, and the intensity of the animals paw prints. This article is designed to lead to a more efficient choice of CatWalk parameters in future studies concerning the functional evaluation of nerve regeneration and simultaneously add to better interstudy comparability. Methods: The aims of the present paper are threefold: (1) to describe the functional method of CatWalk gait analysis, (2) to characterize different parameters acquired by CatWalk gait analysis, and to find the most frequently used parameters as well as (3) to compare their reliability and validity throughout the different studies. Results: In the reviewed articles, the most frequently used parameters were Swing Duration (30), Print Size (27), Stride Length (26), and Max Contact Area (24). Swing Duration was not only frequently used but was also the most reliable and valid parameter. Therefore, we hypothesize that Swing Duration constitutes an important parameter to be chosen for future studies, as it has the highest level of reliability and validity. Conclusion: In conclusion, CatWalk can be used as a complementary approach to other behavioral testing paradigms to assess clinically relevant behavioral benefits, with the main advantage that this system demonstrates both static and dynamic gait parameters at the same time. Due to limited reliability and validity of certain parameters, we recommend that only the most frequently assessed parameters should be used in the future
Late Roman amphora 1: a study of diversification
No full textThis paper draws on petrological work done by the author on the most important type of late Roman amphora - LR1, which was widely distributed in the Mediterranean, Red Sea area and western Britain
Letter from D.F. Goggin, Motor Officer, April 5, 1950
No full textIn this letter, D.F. Goggin, Motor Officer, affirms that Tsugitada Kanamori was employed by his organization starting June 8, 1946 and was still employed there at the time this letter was written. He remarks that Kanamori is a loyal and honest employee and recommends him for any position.This collection contains one box of documents belonging to Tsugitada Kanamori. Materials in this collection mostly pertain to Kanamori’s efforts regarding canceling his renunciation and reinstating his American citizenship
Reconstruction of turbulent pipe-flow profiles from laser Doppler velocimetry data
No full textLaser Doppler velocimetry (LDV) is a powerful experimental tool that finds increasing application in industrial research and product development. For example, LDV may be used to support the development of water, heat, and cooling meters as well as the design and validation of the associated testing and calibration facilities. For such applications, a basic quantity of interest is the volume flow rate Q that can be determined through numerical integration of the velocity profile over the measurement grid. However, under realistic experimental conditions, optical disturbances and reflections may cause corrupted and unreliable data at various measurement points. Here, we study a criterium to identify and reconstruct such data points. The reconstruction criterium is based on the standard error associated with each measurement point. Using some of our LDV data, we show that the error in Q with respect to a reference flow rate may be reduced significantly through the reconstruction. Consequently, the reconstruction criterium allows to establish accurate and reliable flow rates that have potential to be used as a primary validation reference
Letter from D.F. Goggin, Motor Officer, to the American Consul, Yokohama, Japan, April 18, 1951
No full textThis letter confirms that Tsugitada Kanamori has worked for D.F. Goggin since June 1946 at the time this letter was written and has been a model employee.This collection contains one box of documents belonging to Tsugitada Kanamori. Materials in this collection mostly pertain to Kanamori’s efforts regarding canceling his renunciation and reinstating his American citizenship
Depolarization and decreased surface expression of K+ channels contribute to NSAID-inhibition of intestinal restitution
No full textNon-steroidal anti-inflammatory drugs (NSAIDs) contribute to gastrointestinal ulcer formation by inhibiting epithelial cell migration and mucosal restitution; however, the drug-affected signaling pathways are poorly defined. We investigated whether NSAID inhibition of intestinal epithelial migration is associated with depletion of intracellular polyamines, depolarization of membrane potential (Em) and altered surface expression of K+ channels. Epithelial cell migration in response to the wounding of confluent IEC-6 and IEC-Cdx2 monolayers was reduced by indomethacin (100μM), phenylbutazone (100μM) and NS-398 (100μM) but not by SC-560 (1μM). NSAID-inhibition of intestinal cell migration was not associated with depletion of intracellular polyamines. Treatment of IEC-6 and IEC-Cdx2 cells with indomethacin, phenylbutazone and NS-398 induced significant depolarization of Em, whereas treatment with SC-560 had no effect on Em. The Em of IEC-Cdx2 cells was: −38.5±1.8mV under control conditions; −35.9±1.6mV after treatment with SC-560; −18.8±1.2mV after treatment with indomethacin; and −23.7±1.4mV after treatment with NS-398. Whereas SC-560 had no significant effects on the total cellular expression of Kv1.4 channel protein, indomethacin and NS-398 decreased not only the total cellular expression of Kv1.4, but also the cell surface expression of both Kv1.4 and Kv1.6 channel subunits in IEC-Cdx2. Both Kv1.4 and Kv1.6 channel proteins were immunoprecipitated by Kv1.4 antibody from IEC-Cdx2 lysates, indicating that these subunits co-assemble to form heteromeric Kv channels. These results suggest that NSAID inhibition of epithelial cell migration is independent of polyamine-depletion, and is associated with depolarization of Em and decreased surface expression of heteromeric Kv1 channels.ID: S0006295207001931; M3: Article; Accession Number: S0006295207001931; Author: L.C. Freeman (b); Author: D.F. Narvaez (a); Author: A. McCoy (a); Author: F.B. von Stein (c); Author: S. Young (b); Author: K. Silver (a); Author: S. Ganta (b); Author: D. Koch (b); Author: R. Hunter (b); Author: R.F. Gilmour (c); Author: J.D. Lillich (a, ⁎); Affiliation: Department of Clinical Sciences, Kansas State University, Manhattan, KS 66506, United States; Affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, United States; Affiliation: Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, United States; Keyword: Non-steroidal anti-inflammatory drugs; Keyword: Intestinal epithelial cells; Keyword: Membrane potential; Keyword: Potassium channels; Number of Pages: 12; Language: English;Source type: Electronic(1)http://search.ebscohost.com/login.aspx?direct=true&db=edselp&AN=S0006295207001931&site=eds-live&scope=sit
Het Ir. D.F. Woudagemaal: De relatie tussen de ingrepen in het Ir. D.F. Woudagemaal en de aanwijzingen als rijksmonument en werelderfgoed
No full textHet Ir. D.F. Woudagemaal is het grootste functionerende stoomgemaal ter wereld. Dankzij de technische en bouwkundige waarde, is het Woudagemaal in 1977 aangewezen als rijksmonument door de Rijksdienst voor het Cultureel Erfgoed (RCE). Jaren later, in 1998, is het door de United Nations Educational, Scientific and Cultural Organization (UNESCO) opgenomen in de werelderfgoedlijst. Dit betekent dat het stoomgemaal uniek is en absoluut niet verloren mag gaan. Sinds de oplevering in 1920 is het stoomgemaal van civiel ingenieur en architect Dirk Frederik Wouda (1880-1961) ieder jaar in gebruik gesteld. Door de jaren heen heeft het stoomgemaal enkele veranderingen ondergaan. Desalniettemin is de wisselwerking tussen de innovaties, conservering en de aanwijzing als erfgoed onderbelicht. Het doel van deze thesis is daarom om de volgende vraag te beantwoorden: wat is de relatie tussen de ingrepen in het Ir. D. F. Woudagemaal en de aanwijzingen als rijksmonument en werelderfgoed?AR2A011Architecture, Urbanism and Building Science
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