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F Le Vacon

Publications and source records attributed to F Le Vacon.

2 recordsLinked to original sources

[Equipment qualification].

The qualification of the equipment is a particularly important stage in the transfusional process. On the one hand, of many standards such as those of certification or that of accreditation require it, just as the good transfusional practices; in addition, the practices of steps of quality assurance develop this aspect. Indeed, the absence of the realization of this qualification of material having an influence on the finished product, can lead to an error in the product. This qualification passes by various stages of which some are major such as the drafting of the schedule of conditions, the drafting of the operational protocol of qualification, the decision made for the setting in routine. Finally so that this qualification takes all its dimensions it is necessary to carry out methods linked to the international system of measurement. Moreover certain questions after reflexions must find response such as which unit to check, and only this one, the equipment is - it a complex one, is there a maintenance contract? Once all these elements taken into account, the questions having found their answer, the operational protocol will then well be built, the decisions of settings in routine could be done and the sets of the finalized stages.

Accreditation↗

Relationships between susceptibility to LAK cell-mediated lysis, conjugate formation and expression of adhesion molecules in B-cell derived non-Hodgkin's lymphomas.

Adoptive immunotherapy with LAK cells has been investigated for the treatment of B-cell-derived lymphomas, but only a few significant tumor regressions were obtained. In order to explain this refractory state, the sensitivity to normal LAK-mediated lysis of 30 non-Hodgkin's lymphoma (NHL) malignant B-cells was determined using flow cytofluorimetry. A large heterogeneity was found, and we report a close correlation (p < 0.001) between the extent of lysis of malignant B-cells and their ability to form conjugates with LAK cells; which is the first step in LAK-mediated cytolysis. The levels of expression of HLA class I molecules, LFA-1 (CD11a/CD18), CD54 and CD58 were also studied and found to be expressed very heterogeneously. CD54 expression on malignant B-cells plays a major role in the initial conjugate formation with LAK cells (p < 0.001), and this was confirmed by inhibition experiments. Our results suggest that a weak expression of CD54 could constitute one mechanism by which NHL tumor B-cells escape natural immune surveillance and resist LAK cells immunotherapies.

Adult↗