The Experts below are selected from a list of 2019 Experts worldwide ranked by ideXlab platform
Damijan Miklavčič - One of the best experts on this subject based on the ideXlab platform.
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Cell electrofusion using nanosecond electric pulses
Scientific Reports, 2013Co-Authors: Lea Rems, Matej Reberšek, Maša Kandušer, Marko Ušaj, Damijan Miklavčič, Gorazd PuciharAbstract:Electrofusion is an efficient method for fusing cells using short-duration high-voltage electric pulses. However, electrofusion yields are very low when fusion partner cells differ considerably in their size, since the extent of electroporation (consequently membrane fusogenic state) with conventionally used microsecond pulses depends proportionally on the cell radius. We here propose a new and innovative approach to fuse cells with shorter, nanosecond (ns) pulses. Using numerical calculations we demonstrate that ns pulses can induce selective electroporation of the contact areas between cells (i.e. the target areas), regardless of the cell size. We then confirm experimentally on B16-F1 and CHO cell lines that electrofusion of cells with either equal or different size by using ns pulses is indeed feasible. Based on our results we expect that ns pulses can improve fusion yields in electrofusion of cells with different size, such as myeloma cells and B lymphocytes in Hybridoma Technology.
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optimization of bulk cell electrofusion in vitro for production of human mouse heteroHybridoma cells
Bioelectrochemistry, 2008Co-Authors: Katja Trontelj, Matej Reberšek, Maša Kandušer, Vladka Curin Serbec, Marjana Sprohar, Damijan MiklavčičAbstract:Abstract Cell electrofusion is a phenomenon that occurs, when cells are in close contact and exposed to short high-voltage electric pulses. The consequence of exposure to pulses is transient and nonselective permeabilization of cell membranes. Cell electrofusion and permeabilization depend on the values of electric field parameters including amplitude, duration and number of electric pulses and direction of the electric field. In our study, we first investigated the influence of the direction of the electric field on cell fusion in two cell lines. In both cell lines, applications of pulses in two directions perpendicular to each other were the most successful. Cell electrofusion was finally used for production of human–mouse heteroHybridoma cells with modified Koehler and Milstein Hybridoma Technology, which was not done previously. The results, obtained by cell electrofusion, are comparable to usually used polyethylene glycol mediated fusion on the same type of cells.
Peter Keating - One of the best experts on this subject based on the ideXlab platform.
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"Going Monoclonal": Art, Science, and Magic in the Day-to-Day Use of Hybridoma Technology
Social Problems, 2012Co-Authors: Alberto Cambrosio, Peter KeatingAbstract:Recent work in the sociology of science has highlighted the local and tacit dimensions of scientific work. Against the widely held assumption that we are here dealing with a form of knowledge largely beyond the control and manipulation of scientists, we will argue that the unsaid is indeed a part of conscious scientific practice--and hence subject to negotiation, discussion, and construction. Based on a study of the transmission of Hybridoma Technology, this paper will show that questions of local knowledge, tacit knowledge, and "magic," far from being ignored by scientific researchers, are explicitly a part of their daily practice. It will be seen that these questions give rise to a series of social and technical distinctions which are constitutive of scientific work.
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Between fact and technique: The beginnings of Hybridoma Technology
Journal of the History of Biology, 1992Co-Authors: Alberto Cambrosio, Peter KeatingAbstract:At several places in this paper we have made use of a well-known rhetorical device: an argument was made; a character —dubbed “fictional reader” — was then evoked who voiced some objections against that particular argument; and finally, we answered those objections, thus bringing to a close, at least temporarily, our argument. The use of this device raises a question: “How is the presence of the ‘fictional reader” to be understood?” Is it a “mere” rhetorical tool, or does this character designate some particular target? For instance, depending on the context, it could be seen as aimed at different straw men: traditionally minded sociologists, Whiggish historians, well-intentioned philosophers of science. Actually, none of these characters is behind the “fictional reader”. Rather, it refers, potentially, to any of the scientific actors (Milstein, Schwaber, Koprowski, Cohn, and so on) who inhabit our set of narratives. In other words, the “fictional reader” is an icon for the “native” reader/writer who simultaneously produces and questions the products of that particular literary activity known as scientific texts, by explicitly and implicitly raising the issue of the distinction between fact and technique. By following actors in their disputes about the novelty of K & M's contribution, it became apparent that it is not exactly clear which of the different elements of “Hybridoma Technology” should be regarded as “novel.” Was it the use of the P3 myeloma line? Was it the theoretical framework related to the notion of allelic exclusion? Was it ...? In each and every case, arguments can be made for or against the existence of a certain continuity or discontinuity with previous work. And in each case, the determination of novelty, as translated through the continuity/discontinuity issue, appeared to be hanging on the previous attribution of an epistemological status to the object that had allegedly been discovered: was it a fact or a technique? If one focuses on the relatively narrow network of immunogenetics, it could be argued that within that particular evidential context a series of “facts” had been established which, when transferred to other fields, such as the virological research being pursued in Koprowski's institute, were translated into a technique. However, as we have seen, even from an immunogenetic point of view the production of monoclonal antibodies can be viewed as being simultaneously a fact and a technique to establish that fact. Not only, as he himself noted,^139 was Milstein not seeking to develop a technique for the production of monoclonal antibodies when the original experiments were carried out, but the significance later imputed to those experiments was not immediately attributed to them. The paper was seen as one among other papers that used cell fusion techniques to dissect the genetic control of antibody diversity. Distinctions that now appear crucial (e.g.: were the fusion partners two myelomas or a myeloma and a spleen cell?) were easily overlooked. At some point, around 1977, the production of monoclonal antibodies became a goal in itself, no longer linked to the initial immunogenetic network. The transformation of [MILSTEIN 75] into the foundational event of “Hybridoma Technology” was thus achieved. This transformation did not flow naturally from the original experiments. Rather, it involved specific investments which mobilized the activity of a large number of other scientific and industrial actors.^140 A tentative generalization can be deduced from our case study. The dichotomy between fact and technique that underlines much of contemporary science studies seem to be fundamentally misconceived, insofar as the determination of what counts as a fact and what counts as a technique is not possible on a priori grounds. Historians and sociologists of science are confronted with a field of heterogeneous interventions where particular pieces of work are constituted as discrete entities and simultaneously attributed a technical or a factual identity. “Novelty” and “innovation” are precisely the result of such polymorphic attributional processes.
Jean Pierre Dangy - One of the best experts on this subject based on the ideXlab platform.
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antibody mediated neutralization of the exotoxin mycolactone the main virulence factor produced by mycobacterium ulcerans
PLOS Neglected Tropical Diseases, 2016Co-Authors: Jean Pierre Dangy, Philipp Gersbach, Claudio Bomio, Raphael Bieri, Nicole Scherr, Jun Li, Sylwia HuberAbstract:Mycolactone, the macrolide exotoxin produced by Mycobacterium ulcerans, causes extensive tissue destruction by inducing apoptosis of host cells. In this study, we aimed at the production of antibodies that could neutralize the cytotoxic activities of mycolactone.; Using the B cell Hybridoma Technology, we generated a series of monoclonal antibodies with specificity for mycolactone from spleen cells of mice immunized with the protein conjugate of a truncated synthetic mycolactone derivative. L929 fibroblasts were used as a model system to investigate whether these antibodies can inhibit the biological effects of mycolactone. By measuring the metabolic activity of the fibroblasts, we found that anti-mycolactone mAbs can completely neutralize the cytotoxic activity of mycolactone.; The toxin neutralizing capacity of anti-mycolactone mAbs supports the concept of evaluating the macrolide toxin as vaccine target.
Maša Kandušer - One of the best experts on this subject based on the ideXlab platform.
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Cell electrofusion using nanosecond electric pulses
Scientific Reports, 2013Co-Authors: Lea Rems, Matej Reberšek, Maša Kandušer, Marko Ušaj, Damijan Miklavčič, Gorazd PuciharAbstract:Electrofusion is an efficient method for fusing cells using short-duration high-voltage electric pulses. However, electrofusion yields are very low when fusion partner cells differ considerably in their size, since the extent of electroporation (consequently membrane fusogenic state) with conventionally used microsecond pulses depends proportionally on the cell radius. We here propose a new and innovative approach to fuse cells with shorter, nanosecond (ns) pulses. Using numerical calculations we demonstrate that ns pulses can induce selective electroporation of the contact areas between cells (i.e. the target areas), regardless of the cell size. We then confirm experimentally on B16-F1 and CHO cell lines that electrofusion of cells with either equal or different size by using ns pulses is indeed feasible. Based on our results we expect that ns pulses can improve fusion yields in electrofusion of cells with different size, such as myeloma cells and B lymphocytes in Hybridoma Technology.
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optimization of bulk cell electrofusion in vitro for production of human mouse heteroHybridoma cells
Bioelectrochemistry, 2008Co-Authors: Katja Trontelj, Matej Reberšek, Maša Kandušer, Vladka Curin Serbec, Marjana Sprohar, Damijan MiklavčičAbstract:Abstract Cell electrofusion is a phenomenon that occurs, when cells are in close contact and exposed to short high-voltage electric pulses. The consequence of exposure to pulses is transient and nonselective permeabilization of cell membranes. Cell electrofusion and permeabilization depend on the values of electric field parameters including amplitude, duration and number of electric pulses and direction of the electric field. In our study, we first investigated the influence of the direction of the electric field on cell fusion in two cell lines. In both cell lines, applications of pulses in two directions perpendicular to each other were the most successful. Cell electrofusion was finally used for production of human–mouse heteroHybridoma cells with modified Koehler and Milstein Hybridoma Technology, which was not done previously. The results, obtained by cell electrofusion, are comparable to usually used polyethylene glycol mediated fusion on the same type of cells.
Matej Reberšek - One of the best experts on this subject based on the ideXlab platform.
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Cell electrofusion using nanosecond electric pulses
Scientific Reports, 2013Co-Authors: Lea Rems, Matej Reberšek, Maša Kandušer, Marko Ušaj, Damijan Miklavčič, Gorazd PuciharAbstract:Electrofusion is an efficient method for fusing cells using short-duration high-voltage electric pulses. However, electrofusion yields are very low when fusion partner cells differ considerably in their size, since the extent of electroporation (consequently membrane fusogenic state) with conventionally used microsecond pulses depends proportionally on the cell radius. We here propose a new and innovative approach to fuse cells with shorter, nanosecond (ns) pulses. Using numerical calculations we demonstrate that ns pulses can induce selective electroporation of the contact areas between cells (i.e. the target areas), regardless of the cell size. We then confirm experimentally on B16-F1 and CHO cell lines that electrofusion of cells with either equal or different size by using ns pulses is indeed feasible. Based on our results we expect that ns pulses can improve fusion yields in electrofusion of cells with different size, such as myeloma cells and B lymphocytes in Hybridoma Technology.
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optimization of bulk cell electrofusion in vitro for production of human mouse heteroHybridoma cells
Bioelectrochemistry, 2008Co-Authors: Katja Trontelj, Matej Reberšek, Maša Kandušer, Vladka Curin Serbec, Marjana Sprohar, Damijan MiklavčičAbstract:Abstract Cell electrofusion is a phenomenon that occurs, when cells are in close contact and exposed to short high-voltage electric pulses. The consequence of exposure to pulses is transient and nonselective permeabilization of cell membranes. Cell electrofusion and permeabilization depend on the values of electric field parameters including amplitude, duration and number of electric pulses and direction of the electric field. In our study, we first investigated the influence of the direction of the electric field on cell fusion in two cell lines. In both cell lines, applications of pulses in two directions perpendicular to each other were the most successful. Cell electrofusion was finally used for production of human–mouse heteroHybridoma cells with modified Koehler and Milstein Hybridoma Technology, which was not done previously. The results, obtained by cell electrofusion, are comparable to usually used polyethylene glycol mediated fusion on the same type of cells.
