ZIB

Hits per page

hits 1 - 2 | 2 hits

Sorting

Electronic Resource

Megakaryothrombopoiesis During Ex Vivo Expansion of Human Cord Blood CD34+ Cells Using Thrombopoietin (2002)

Woo, S.-Y. ; Kie, J.-H. ; Ryu, K.-H. ; [et al.]

Oxford, UK : Blackwell Science Ltd

Scandinavian journal of immunology 55 (2002), S. 0

add to mindlist on the mindlist

Details

ISSN: 1365-3083

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Medicine

Notes: Thrombopoietin (TPO) is one of the most promising stimulants for ex vivo expansion of haematopoietic stem cells. Previously, we have found that TPO induces a characteristic pattern of apoptosis during ex vivo expansion of human cord blood (CB) CD34+ cells and that the TPO-induced apoptotic cells belong to megakaryocyte (MK) lineage. In this study, we have examined the maturation of MK and platelet production in association with the TPO-induced apoptosis. CD34+ cells, purified from human CB, were expanded in serum-free conditions stimulated with TPO. Apoptosis was confirmed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) assay and electron microscopy (EM). Simultaneous measurement of DNA content and immunophenotyping revealed that the cells with higher DNA content (〉8 N) constituted less than 5% of the CD41+ fractions until day 14, implying premature apoptosis of MKs before full polyploidization. Nevertheless, EM observation showed not only platelet territories but also newly produced platelets in which granules and microfilaments could be identified. Furthermore, flow cytometry demonstrated that the platelet fraction expressed P-selectin and an activation motif on GPIIb/IIIa recognized by monoclonal antibody PAC-1 upon stimulation with adenosine diphosphate (ADP). In addition, periodic acid-Schiff (PAS)-positive materials and nonspecific esterase activities could be demonstrated. Therefore, it is suggested that platelet production and the accompanying processes, rather than apoptosis only, be hastened during the ex vivo expansion of CB CD34+ cells when using TPO.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1046/j.1365-3083.2002.01031.x

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Use of reciprocal modal vectors for nonlinearity detection (2000)

Chong, Y. H. ; Imregun, M.

Springer

Archive of applied mechanics 70 (2000), S. 453-462

add to mindlist on the mindlist

Details

ISSN: 1432-0681

Keywords: Key words Experiment ; modal analysis ; frequency response ; harmonic balance ; friction damping ; cubic stiffness

Source: Springer Online Journal Archives 1860-2000

Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Notes: Summary This paper seeks to exploit the reciprocal modal vector orthogonality between experimentally-derived mode shapes and the corresponding measured frequency response functions in order to derive a criterion for the detection of structural non-linearities. Being based on the use of measured data and experimentally-derived quantities only, the method is directly applicable to practical engineering cases for which there are usually no spatial descriptions. A brief outline of the reciprocal modal vector theory is given first, followed by a short description of a frequency-domain nonlinear response simulation technique using a harmonic balance approach. A detailed study of a 4-DOF system with cubic stiffness and friction damping nonlinearities is presented next. It is shown that the proposed nonlinearity detection criterion is relatively insensitive to measurement noise. It is concluded that the method is effective for detecting nonlinear behaviour in a consistent and quantitative fashion.