The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Sebastian Sauerbier - One of the best experts on this subject based on the ideXlab platform.
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in vivo comparison of hard tissue regeneration with ovine mesenchymal stem cells processed with either the Ficoll method or the bmac method
Journal of Cranio-maxillofacial Surgery, 2015Co-Authors: Nina Ardjomandi, Fabian Duttenhoefer, Sebastian Sauerbier, Samuel Porfirio Xavier, Toshiyuki Oshima, A KuenzAbstract:Abstract Introduction The aim of this work was to analyse the suitability of mesenchymal stem cell isolation by Ficoll density centrifugation and the closed bone marrow aspirate concentrate (BMAC) system for sinus augmentation with bovine bone mineral (BBM) in the sheep model. Methods 16 sheep underwent sinus augmentation with BBM and MSCs; they were divided between two groups with survival points of 8 and 16 weeks. For the Ficoll control arm three, and for the BMAC test arm, five augmentations were performed for each time point. The derived cell numbers were counted; a colony forming unit (CFU) assay was performed; the pluripotency of the MSCs was proved; histological and histomorphometrical analysis were performed. Results The approach of using BBM and MSCs in combination with fibrin adhesive was sufficient for new bone formation as the Ficoll experiment indicated. However, due to significantly lower cell numbers isolated using the BMAC in sheep, less new bone was formed in the test arm. Conclusions The BMAC system is well suited for human MSC isolation but it needs to be optimized to fit sheep cell characteristics if it is to be used in this animal model.
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follow up of implant survival comparing Ficoll and bone marrow aspirate concentrate methods for hard tissue regeneration with mesenchymal stem cells in humans
BioResearch Open Access, 2014Co-Authors: Fabian Duttenhoefer, Stefan F Hieber, Andres Stricker, Rainer Schmelzeisen, Ralf Gutwald, Sebastian SauerbierAbstract:Abstract Objective: Clinical follow-up of implant survival in 11 patients comparing two different methods for mesenchymal stem cell (MSC) isolation (Ficoll and bone marrow aspirate concentrate [BMAC]) applied in maxillary sinus augmentation. Methods: Mononuclear cells, including MSCs, were concentrated with either Ficoll (control group, n=6 sinus) or BMAC (test group, n=12 sinus) and transplanted in combination with bovine bone mineral. A total of 50 implants were placed in a second surgical intervention (17 Ficoll/33 BMAC) and loaded after 4 months. Overall implant survival was assessed with a Kaplan-Meier model using package survival under R. Results: Implant survival of the Ficoll group was 100% compared with the BMAC group, which had 93.4% survival (95% confidence interval, 0.849–1). The difference between the groups was not significant (p=0.381). Conclusion: The BMAC system is an effective and suitable “chair-side” method for clinical application in hard tissue regeneration.
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in vivo comparison of hard tissue regeneration with human mesenchymal stem cells processed with either the Ficoll method or the bmac method
Tissue Engineering Part C-methods, 2010Co-Authors: Sebastian Sauerbier, Andres Stricker, Rainer Schmelzeisen, Samuel Porfirio Xavier, Toshiyuki Oshima, Jens Kuschnierz, Felicia Buhler, Ralf GutwaldAbstract:OBJECTIVE To compare new bone formation in maxillary sinus augmentation procedures using biomaterial associated with mesenchymal stem cells (MSCs) separated by two different isolation methods. BACKGROUND In regenerative medicine open cell concentration systems are only allowed for clinical application under good manufacturing practice conditions. METHODS Mononuclear cells, including MSCs, were concentrated with either the synthetic polysaccharide (Ficoll) method (classic open system--control group, n = 6 sinus) or the bone marrow aspirate concentrate (BMAC) method (closed system--test group, n = 12 sinus) and transplanted in combination with biomaterial. A sample of the cells was characterized by their ability to differentiate. After 4.1 months (SD +/- 1.0) bone biopsies were obtained and analyzed. RESULTS The new bone formation in the BMAC group was 19.9% (90% confidence interval [CI], 10.9-29), and in the Ficoll group was 15.5% (90% CI, 8.6-22.4). The 4.4% difference was not significant (90% CI, -4.6-13.5; p = 0.39). MSCs could be differentiated into osteogenic, chondrogenic, and adipogenic lineages. CONCLUSION MSCs harvested from bone marrow aspirate in combination with bovine bone matrix particles can form lamellar bone and provide a reliable base for dental implants. The closed BMAC system is suited to substitute the open Ficoll system in bone regeneration procedures.
Smita Ghanekar - One of the best experts on this subject based on the ideXlab platform.
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vacutainer cpt and Ficoll density gradient separation perform equivalently in maintaining the quality and function of pbmc from hiv seropositive blood samples
BMC Immunology, 2006Co-Authors: Joyce J Ruitenberg, Candice B Mulder, Vernon C Maino, Alan L Landay, Smita GhanekarAbstract:For immune monitoring studies during HIV vaccine clinical trials, whole blood specimens from HIV seropositive (HIV+) patients may be collected at multiple sites and sent to a central location for peripheral blood mononuclear cell (PBMC) isolation, cryopreservation and functional evaluation. In this study we show a comparison of two PBMC preparation options, Ficoll density gradient separation (Ficoll) and Cell Preparation Tubes (CPT) using shipped whole blood specimens from 19 HIV+ patients (CD4 > 350, viral load < 50). The pre- and post- cryopreservation performance of samples collected by these two methods were compared by assessment of antigen-specific IFNγ expression in CD8+ and CD8- T cells, cellular viability, and cellular recovery. The results indicate that cryopreserved PBMC samples tested for CMV- and HIV- specific interferon-gamma (IFNγ) expression performed equivalent to the respective fresh PBMC processed under both collection conditions. Compared to fresh PBMC, the viability was significantly lower for cryopreserved PBMC derived using Ficoll, although it was never less than 90%. There were no significant differences in the IFNγ response, viability, or recovery between cryopreserved PBMC derived by Ficoll and by CPT. These data suggest that CPT is an efficient system for the collection and cryopreservation of functionally active HIV+ PBMC, as well as a viable alternative to Ficoll gradient separation.
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vacutainer cpt and Ficoll density gradient separation perform equivalently in maintaining the quality and function of pbmc from hiv seropositive blood samples
BMC Immunology, 2006Co-Authors: Joyce J Ruitenberg, Candice B Mulder, Vernon C Maino, Alan Landay, Smita GhanekarAbstract:Background For immune monitoring studies during HIV vaccine clinical trials, whole blood specimens from HIV seropositive (HIV+) patients may be collected at multiple sites and sent to a central location for peripheral blood mononuclear cell (PBMC) isolation, cryopreservation and functional evaluation. In this study we show a comparison of two PBMC preparation options, Ficoll density gradient separation (Ficoll) and Cell Preparation Tubes (CPT) using shipped whole blood specimens from 19 HIV+ patients (CD4 > 350, viral load < 50). The pre- and post- cryopreservation performance of samples collected by these two methods were compared by assessment of antigen-specific IFNγ expression in CD8+ and CD8- T cells, cellular viability, and cellular recovery.
David M Rothstein - One of the best experts on this subject based on the ideXlab platform.
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islet filtration a simple and rapid new purification procedure that avoids Ficoll and improves islet mass and function
Transplantation, 2002Co-Authors: Paolo R Salvalaggio, Songyang Deng, Charlotte E Ariyan, Isabelle Millet, Walter S Zawalich, Giacomo Basadonna, David M RothsteinAbstract:Islet isolation is a time-consuming process. Islet yields vary, and previous in vitro studies suggest that Ficoll may be an islet toxin. Here, we describe an alternative, Ficoll-free method to purify murine islets by filtration through a cell strainer. Collagenase digestion of pancreata was carried out using standard procedures. The pancreatic digest was divided into aliquots and purified either by Ficoll or by filtration. Following filtration, islets were intact and separated from nondigested tissue. Purity was similar to that achieved using Ficoll. However, purification by filtration was faster, increased islet yield, and resulted in higher insulin secretion in vitro. Moreover, when syngeneic diabetic hosts were transplanted with a marginal islet mass, islets purified by filtration restored normoglycemia significantly faster than those isolated by Ficoll. This suggests that Ficoll exposure negatively impacts islet function. In conclusion, islet filtration is a simple and rapid procedure for purification of islets that demonstrate improved functional mass.
Bondada Subbarao - One of the best experts on this subject based on the ideXlab platform.
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physiology of murine b lymphocytes ii life spans of mitogen and thymus independent antigen type 2 reactive b lymphocytes from aged mice
Mechanisms of Ageing and Development, 1991Co-Authors: Venkatachalam Udhayakumar, Niranjan S Goud, Richard J Cross, Bondada SubbaraoAbstract:Abstract We showed earlier that life spans of murine B lymphocytes could be estimated by measuring the functional reactivities of normal B cells upon transfer into x-linked immunodeficient (xid) mice, which do not respond to anti-mouse IgM (anti-μ) antibodies and thymic-independent type -2 (TI-2) antigens. Here the same approach was adopted, to evaluate the life spans of B-lymphocytes from aged mice. Spleen cells from normal young and aged mice were transferred into young or aged xid recipients and the decay kinetics were followed by measuring the proliferative response to anti-μ and PFC response to TNP-Ficoll, a prototype TI-2 antigen. The results indicated that anti-μ reactive B cells of both young and aged mice decayed with similar non-linear kinetics. About 50% of the donor cells decayed in 8–10 days, whereas, the remaining decayed at a slower rate and it appeared that the median life-expectancy of this latter population could be at least 3 weeks. Essentially, there was no apparent difference in the decay kinetics of anti-μ reactive B cells of young and aged mice. Unlike anti-μ reactive cells, TNP-Ficoll reactive B cells showed 2–3-fold enhancement in the PFC response during the first 2 weeks, and persisted at least until 5 weeks post transfer. This result indicated that TNP-Ficoll reactive B cells are long-lived. Further, it was found that the turn over rate of TNP-Ficoll reactive B
Joyce J Ruitenberg - One of the best experts on this subject based on the ideXlab platform.
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vacutainer cpt and Ficoll density gradient separation perform equivalently in maintaining the quality and function of pbmc from hiv seropositive blood samples
BMC Immunology, 2006Co-Authors: Joyce J Ruitenberg, Candice B Mulder, Vernon C Maino, Alan L Landay, Smita GhanekarAbstract:For immune monitoring studies during HIV vaccine clinical trials, whole blood specimens from HIV seropositive (HIV+) patients may be collected at multiple sites and sent to a central location for peripheral blood mononuclear cell (PBMC) isolation, cryopreservation and functional evaluation. In this study we show a comparison of two PBMC preparation options, Ficoll density gradient separation (Ficoll) and Cell Preparation Tubes (CPT) using shipped whole blood specimens from 19 HIV+ patients (CD4 > 350, viral load < 50). The pre- and post- cryopreservation performance of samples collected by these two methods were compared by assessment of antigen-specific IFNγ expression in CD8+ and CD8- T cells, cellular viability, and cellular recovery. The results indicate that cryopreserved PBMC samples tested for CMV- and HIV- specific interferon-gamma (IFNγ) expression performed equivalent to the respective fresh PBMC processed under both collection conditions. Compared to fresh PBMC, the viability was significantly lower for cryopreserved PBMC derived using Ficoll, although it was never less than 90%. There were no significant differences in the IFNγ response, viability, or recovery between cryopreserved PBMC derived by Ficoll and by CPT. These data suggest that CPT is an efficient system for the collection and cryopreservation of functionally active HIV+ PBMC, as well as a viable alternative to Ficoll gradient separation.
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vacutainer cpt and Ficoll density gradient separation perform equivalently in maintaining the quality and function of pbmc from hiv seropositive blood samples
BMC Immunology, 2006Co-Authors: Joyce J Ruitenberg, Candice B Mulder, Vernon C Maino, Alan Landay, Smita GhanekarAbstract:Background For immune monitoring studies during HIV vaccine clinical trials, whole blood specimens from HIV seropositive (HIV+) patients may be collected at multiple sites and sent to a central location for peripheral blood mononuclear cell (PBMC) isolation, cryopreservation and functional evaluation. In this study we show a comparison of two PBMC preparation options, Ficoll density gradient separation (Ficoll) and Cell Preparation Tubes (CPT) using shipped whole blood specimens from 19 HIV+ patients (CD4 > 350, viral load < 50). The pre- and post- cryopreservation performance of samples collected by these two methods were compared by assessment of antigen-specific IFNγ expression in CD8+ and CD8- T cells, cellular viability, and cellular recovery.