Search results for " Separation"
showing 10 items of 724 documents
Highly protective in vivo function of cytomegalovirus IE1 epitope-specific memory CD8 T cells purified by T-cell receptor-based cell sorting.
2005
ABSTRACTReconstitution of antiviral CD8 T cells is essential for controlling cytomegalovirus (CMV) infection after bone marrow transplantation. Accordingly, polyclonal CD8 T cells derived from BALB/c mice infected with murine CMV protect immunocompromised adoptive transfer recipients against CMV disease. The protective population comprises CD8 T cells with T-cell receptors (TCRs) specific for defined and for as-yet-unknown viral epitopes, as well as a majority of nonprotective cells with unrelated specificities. Defined epitopes include IE1/m123 and m164, which are immunodominant in terms of the magnitude of the CD8 T-cell response, and a panel of subordinate epitopes (m04, m18, M45, M83, a…
TH17 cells mediate pulmonary collateral priming
2010
Background Our laboratory has shown that inhalational sensitization to new antigens is facilitated through an ongoing T H 2-polarized inflammation of the lung, a phenomenon we call "collateral priming." Objective We were interested to analyze whether a T H 1-polarized pulmonary inflammation also facilitates priming toward new antigens and which cytokine or cytokines are involved. Methods T H 1-polarized T cells were generated in vitro and transferred into congenic mice. Mice were challenged initially with cognate antigen and an unrelated antigen; consecutively, they received cognate antigen or the secondary antigen. Airway inflammation, antigen-specific IgG2a levels, and airway hyperrespons…
Study of Selective Adsorption of Gases by Calorimetry
2013
This chapter is devoted to the study of coadsorption of gases in nanoporous solids by using the differential calorimetry. In the first part, the thermodynamic principles of adsorption of gases are recalled. Some of them have already presented in chapter one. However a special attention has been paid here to the determination of the adsorption enthalpies and entropies and we focused on the selective adsorption of binary mixtures. Then the specific experimental technique based on the combination of differential calorimetry with manometry and gas phase chromatography or mass spectrometry is shown in details. In the last part, the thermodynamic concepts on coadsorption are illustrated with expe…
Evaluation of the stromal vascular fraction of adipose tissue as the basis for a stem cell-based tissue-engineered vascular graft
2017
Abstract Objective One of the rate-limiting barriers within the field of vascular tissue engineering is the lengthy fabrication time associated with expanding appropriate cell types in culture. One particularly attractive cell type for this purpose is the adipose-derived mesenchymal stem cell (AD-MSC), which is abundant and easily harvested from liposuction procedures. Even this cell type has its drawbacks, however, including the required culture period for expansion, which could pose risks of cellular transformation or contamination. Eliminating culture entirely would be ideal to avoid these concerns. In this study, we used the raw population of cells obtained after digestion of human lipo…
Curasan PRP kit vs. PCCS PRP system
2002
An important reason to improve methods of isolating platelet-rich plasma (PRP) is the potential use of autologous thrombocyte growth factors. In addition to discontinuous cell separation, two methods for extracting PRP that can be performed directly by the surgeon are now available. This study compared the suitability of these two methods for the preparation of PRP. Whole blood was drawn from 47 healthy donors (18 men, 29 women) aged 20-59 years (mean 29.9, SD 7.7). For each donor, PRP was separated by the PCCS method (PCCS Kit, 3i Implant Innovations, Palm Beach Gardens, FL, USA) and by the Curasan method (analogous to the PRP kit, Curasan, Kleinostheim, Germany). Thrombocyte counts differ…
Quantification of thrombocyte growth factors in platelet concentrates produced by discontinuous cell separation.
2002
Platelet concentrates (PC) are increasingly used to increase bone regeneration in pre-prosthetic surgery. Although it is generally appreciated that certain growth factors (PDGF, TGF, EGF, and ECGF) are present in thrombocyte preparations, relatively little is known about these components in quantitative terms. The study reported here analysed the amounts of growth factors in PC produced under standard conditions from healthy volunteers. All the blood samples (237 in total) were analysed using Quantikine ELISA kits (R and D). The mean +/- SD platelet count in whole blood from these donors was 262,000+/-58,000/microl, while in PC produced by discontinuous cell separation it was 1.419,000+/-33…
Advanced Platelet-Rich Fibrin: A New Concept for Cell-Based Tissue Engineering by Means of Inflammatory Cells
2014
Choukroun's platelet-rich fibrin (PRF) is obtained from blood without adding anticoagulants. In this study, protocols for standard platelet-rich fibrin (S-PRF) (2700 rpm, 12 minutes) and advanced platelet-rich fibrin (A-PRF) (1500 rpm, 14 minutes) were compared to establish by histological cell detection and histomorphometrical measurement of cell distribution the effects of the centrifugal force (speed and time) on the distribution of cells relevant for wound healing and tissue regeneration. Immunohistochemistry for monocytes, T and B -lymphocytes, neutrophilic granulocytes, CD34-positive stem cells, and platelets was performed on clots produced from four different human donors. Platelets …
Depletion of naive T cells using clinical grade magnetic CD45RA beads: a new approach for GVHD prophylaxis
2013
Depletion of naive T cells from donor leukapheresis products (LPs) aims at the reduction of alloreactivity, while preserving memory T-cell reactivity (for example, to pathogens). This study established the immunomagnetic depletion procedure under clean room conditions using CD45RA beads and analyzed LPs of six donors for cell composition and functional immune responses. CD45RA depletion resulted in 3.4-4.7 log (median 4.4) reduction of CD45RA(+) T cells, thereby eliminating naive and late effector T cells. B cells were also completely removed, whereas significant proportions of NK cells, monocytes and granulocytes persisted. CD45RA-depleted LPs contained effector and central memory CD4(+) a…
Functional characterization of hepatocytes for cell transplantation: customized cell preparation for each receptor.
2009
The first indication of hepatocyte transplantation is inborn liver-based metabolic disorders. Among these, urea cycle disorders leading to the impairment to detoxify ammonia and Crigler-Najjar Syndrome type I, a deficiency in the hepatic UDP-glucuronosyltransferase 1A1 present the highest incidence. Metabolically qualified human hepatocytes are required for clinical infusion. We proposed fast and sensitive procedures to determine their suitability for transplantation. For this purpose, viability, attachment efficiency, and metabolic functionality (ureogenic capability, cytochrome P450, and phase II activities) are assayed prior to clinical cell infusion to determine the quality of hepatocyt…
Detection of residual leukemic blasts in adult patients with acute T-lymphoblastic leukemia using bone marrow trephine biopsies: comparison of fluore…
2010
Evaluation of remission in adult acute lymphoblastic leukemia (ALL) normally relies on cytologic evaluation and flow-cytometric analysis. The diagnostic impact of bone marrow trephine biopsies has not been studied so far. We investigated 26 biopsies of 16 patients with T-ALL. Double fluorescent immunostaining with TdT and CD3 was performed. Corresponding cytologic evaluation and flow-cytometric data were available. In 17 of 26 investigations, the results were concordant (either positive or negative). In one examination, residual blasts were not recognized by trephine biopsy, but by other methods. By contrast, in eight investigations, the leukemic blasts were found only in the bone marrow tr…