The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform

Gerhard Gstraunthaler - One of the best experts on this subject based on the ideXlab platform.

  • Fetal Bovine Serum (FBS) - A pain in the dish?
    Atla-alternatives To Laboratory Animals, 2020
    Co-Authors: Jan Van Der Valk, Gerhard Gstraunthaler
    Abstract:

    The use of Fetal Bovine Serum in replacement alternative methods is associated with serious animal welfare concerns, as well as worrying reproducibility issues

  • alternatives to the use of Fetal Bovine Serum Serum free cell culture
    ALTEX-Alternatives to Animal Experimentation, 2003
    Co-Authors: Gerhard Gstraunthaler
    Abstract:

    : Serum is commonly used as a supplement to cell culture media. It provides a broad spectrum of macromolecules, carrier proteins for lipoid substances and trace elements, attachment and spreading factors, low molecular weight nutrients, and hormones and growth factors. The most widely used animal Serum supplement is Fetal Bovine Serum, FBS. Since Serum in general is an ill-defined component in cell culture media, a number of chemically defined Serum-free media formulations have been developed in the last two decades. Besides modern cell biological advances in cell and tissue culture and efforts towards a standardisation of cell culture protocols in Good Cell Culture Practice, in addition, considerable ethical concerns were raised recently about the harvest and collection of Fetal Bovine Serum. Thus, in order to decrease the annual need for Bovine fetuses in terms of the 3Rs through any reduction in the use or partial replacement of Serum, as well as in terms of an improvement of cell and tissue culture methodology, Serum-free cell culture represents a modern, valuable and scientifically well accepted alternative to the use of FBS in cell and tissue culture.

Wen Wang - One of the best experts on this subject based on the ideXlab platform.

Angelo Azzi - One of the best experts on this subject based on the ideXlab platform.

  • hydrogen peroxide and Fetal Bovine Serum induced dna synthesis in vascular smooth muscle cells positive and negative regulation by protein kinase c isoforms
    Biochimica et Biophysica Acta, 1995
    Co-Authors: Mara Fiorani, Orazio Cantoni, A Tasinato, D Boscoboinik, Angelo Azzi
    Abstract:

    Hydrogen peroxide and Fetal Bovine Serum stimulate DNA synthesis in growth-arrested smooth muscle cells with remarkably similar kinetics and cell density dependence. However, while stimulation with Fetal Bovine Serum results in cell proliferation, that by H2O2 is followed by cell death. Depletion of conventional and novel protein kinase C isoforms, resulting from a long treatment with phorbol-12-myristate-13-acetate, further increases H2O2-induced DNA synthesis. On the other hand, the specific protein kinase C inhibitor calphostin C abolished the increased DNA synthesis promoted by Fetal Bovine Serum or H2O2. H2O2 increases protein kinase C activity in smooth muscle cells. This effect is markedly reduced, but not abolished, by down-regulation of the alpha, delta and epsilon protein kinase C isoforms. Thus, the zeta isoform of protein kinase C, which is not down-regulated, may be responsible for the residual H2O2 stimulation of protein kinase C. In conclusion, the results obtained show that H2O2 stimulates protein kinase C activity and DNA synthesis in growth-arrested smooth muscle cells: these events are not followed by cell proliferation but rather by cell death. This H2O2 stimulated DNA synthesis appears to be negatively controlled by alpha, delta and epsilon isoforms and positively controlled by the zeta isoform of protein kinase C.

Wolfgang Wagner - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of human platelet lysate versus Fetal Bovine Serum for culture of mesenchymal stromal cells
    Cytotherapy, 2014
    Co-Authors: Hatim Hemeda, Bernd Giebel, Wolfgang Wagner
    Abstract:

    Abstract Culture media for therapeutic cell preparations—such as mesenchymal stromal cells (MSCs)—usually comprise Serum additives. Traditionally, Fetal Bovine Serum is supplemented in basic research and in most clinical trials. Within the past years, many laboratories adapted their culture conditions to human platelet lysate (hPL), which further stimulates proliferation and expansion of MSCs. Particularly with regard to clinical application, human alternatives for Fetal Bovine Serum are clearly to be preferred. hPL is generated from human platelet units by disruption of the platelet membrane, which is commonly performed by repeated freeze and thaw cycles. Such culture supplements are notoriously ill-defined, and many parameters contribute to batch-to-batch variation in hPL such as different amounts of plasma, a broad range of growth factors and donor-specific effects. The plasma components of hPL necessitate addition of anticoagulants such as heparins to prevent gelatinization of hPL medium, and their concentration must be standardized. Labels for description of hPL—such as “xenogen-free,” “animal-free” and “Serum free”—are not used consistently in the literature and may be misleading if not critically assessed. Further analysis of the precise composition of relevant growth factors, attachment factors, microRNAs and exosomes will pave the way for optimized and defined culture conditions. The use of hPL has several advantages and disadvantages: they must be taken into account because the choice of cell culture additive has major impact on cell preparations.

H Karaki - One of the best experts on this subject based on the ideXlab platform.

  • Dexamethasone prevents impairment of endothelium-dependent relaxation in arteries cultured with Fetal Bovine Serum
    European Journal of Pharmacology, 2005
    Co-Authors: Takahisa Murata, H Yamawaki, K Sato, M Hori, H Karaki, Natsuko Suzuki, H Ozaki
    Abstract:

    Abstract In the present study, we assessed the effects of dexamethasone on Fetal Bovine Serum-induced dysfunction of mesenteric endothelial cells using an organ culture procedure. In rabbit mesenteric arteries cultured in the presence of 10% Fetal Bovine Serum for 7 days, the endothelium-dependent, nitric oxide (NO)-mediated relaxations caused by substance P and ionomycin were decreased as compared to those in non-treated arteries. Dexamethasone (3 μM) inhibited the proliferative stimuli-induced endothelial dysfunction without affecting the contractility or NO susceptibility of smooth muscle cells. Cross-sectioned hematoxylin–eosin staining and whole-mount CD31 staining indicated that chronic proliferative stimulation induced detachment of endothelial cells from the tunica intima in some regions, and also caused thickening of the arterial wall and shortening of the internal diameter. Endothelial NO synthesis (eNOS) mRNA expression was also decreased by the treatment with Fetal Bovine Serum. The dexamethasone treatment did not inhibit the smooth muscle hypertrophy, but it inhibited the peeling of endothelial cells and recovered the eNOS mRNA expression. These results suggest that DEX ameliorate the impairments of arterial relaxation induced by proliferative stimuli and that these beneficial effects may be mediated by maintaining the adhesion of endothelial cells to the vascular wall and/or by recovering eNOS mRNA expression.

  • morphological and functional changes of rabbit mesenteric artery cultured with Fetal Bovine Serum
    Life Sciences, 2000
    Co-Authors: H Yamawaki, K Sato, M Hori, H Ozaki, Shinichiro Nakamura, Hiroyuki Nakayama, H Karaki
    Abstract:

    Abstract The aim of this study was to examine the morphological and functional changes in rabbit mesenteric arterial tissue cultured with Fetal Bovine Serum. In the endothelium-denuded arteries cultured under a Serum-free condition for one week (Serum-free arteries), morphology of the smooth muscle layer was intact. In the Serum-free arteries, high K + -induced contraction did not change but norepinephrine-induced contraction slightly decreased compared with that in the freshly isolated arteries, whereas the sensitivity to these stimulants was significantly augmented. In the medial layer of the arteries cultured with 10% Fetal Bovine Serum for one week (Serum-treated arteries), proliferation, disorientation and death of smooth muscle cells were observed. In the Serum-treated arteries, both the amplitude of contractions induced by high K + and norepinephrine and the sensitivity to these stimulants were significantly reduced compared with those of the Serum-free arteries. The reduced norepinephrine-induced contraction in the Serum-treated arteries was partially recovered by adding N G -monomethyl-L-arginine (L-NMMA), a nitric oxide (NO) synthase inhibitor, to the assay medium. In α-toxin permeabilized arteries, the amplitude of Ca 2 +-induced contraction and the sensitivity of the contractile apparatus to Ca 2 + were significantly reduced after Serum-treatment. These results suggest that chronic Serum-treatment of rabbit mesenteric arteries impairs muscle contractility by the morphological and phenotypic changes in smooth muscle cells. NO production in smooth muscle cells is also responsible for the decreased contractility after the Serum-treatment.

  • Impairment of endothelium-dependent relaxation in the arteries cultured with Fetal Bovine Serum.
    European journal of pharmacology, 1999
    Co-Authors: H Yamawaki, K Sato, M Hori, H Ozaki, H Karaki
    Abstract:

    Effects of chronic treatment with Fetal Bovine Serum on the function of vascular endothelium were examined using an organ culture system. In the rabbit mesenteric arteries cultured with 10% Fetal Bovine Serum for 7 days, the substance P- or ionomycin-induced endothelium-dependent relaxation was significantly attenuated compared to the arteries cultured in the Serum-free condition. The effects of the Serum were concentration- and time-dependent. By the treatment with the Serum, the amounts of nitric oxide (NO) production and total mRNA for endothelial NO synthase were reduced, whereas the sodium nitroprusside-induced relaxation was rather augmented. These results suggest that chronic treatment of rabbit mesenteric artery with Fetal Bovine Serum decreases endothelial NO synthase mRNA, reduces NO production and impairs endothelium-dependent relaxation.