[Manufacture of DNA chips in a laboratory for internal use: legislation and quality assurance]. / Fabrication de puces à ADN par un laboratoire pour sa propre utilisation: réglementation et assurance qualité

Manufacturing and using DNA chips in a laboratory, while respecting legality and good practices, require a review of the regulatory framework and relevant documentation for implementing a quality assurance system. Using DNA chips, either as a research tool, or as an in vitro diagnostic medical device, does not come within the same regulations: none in the first case, and european directive 98/79/CE in the second one. It is the same for research practice, for which the law to be enforced has been primarily conditioned to ethics, while carrying out medical analyses has been framed in France by the GBEA. The regulatory approach laid down in the GBEA is a first step for implementing a quality assurance system, but this must be extended to the manufacturing process of DNA chips. International standards (ISO 9001: 2000, ISO/IEC 15189...) provide documentation to meet this last requirement, but also enable one to carry on the quality approach up to the certification of the laboratory or its accreditation.

G388R mutation of the FGFR4 gene is not relevant to breast cancer prognosis.

This study screened large cohorts of node-positive and node-negative breast cancer patients to determine whether the G388R mutation of the FGFR4 gene is a useful prognostic marker for breast cancer as reported by Bange et al in 2002. Node-positive (n=139) and node-negative (n=95) breast cancer cohorts selected for mutation screening were followed up for median periods of 89 and 87 months, respectively. PCR - RFLP analysis was modified to facilitate molecular screening. Curves for disease-free survival were plotted according to the Kaplan - Meier method, and a log-rank test was used for comparisons between groups. Three other nonparametric linear rank-tests particularly suitable for investigating possible relations between G388R mutation and early cancer progression were also used. Kaplan - Meier analysis based on any of the four nonparametric linear rank tests performed for node-positive and node-negative patients was not indicative of disease-free survival time. G388R mutation of the FGFR4 gene is not relevant for breast cancer prognosis.

Expression of the Na(+)/Ca(2+) exchanger in skeletal muscle.

The expression of the Na(+)/Ca(2+) exchanger was studied in differentiating muscle fibers in rats. NCX1 and NCX3 isoform (Na(+)/Ca(2+) exchanger isoform) expression was found to be developmentally regulated. NCX1 mRNA and protein levels peaked shortly after birth. Conversely, NCX3 isoform expression was very low in muscles of newborn rats but increased dramatically during the first 2 wk of postnatal life. Immunocytochemical analysis showed that NCX1 was uniformly distributed along the sarcolemmal membrane of undifferentiated rat muscle fibers but formed clusters in T-tubular membranes and sarcolemma of adult muscle. NCX3 appeared to be more uniformly distributed along the sarcolemma and inside myoplasm. In the adult, NCX1 was predominantly expressed in oxidative (type 1 and 2A) fibers of both slow- and fast-twitch muscles, whereas NCX3 was highly expressed in fast glycolytic (2B) fibers. NCX2 was expressed in rat brain but not in skeletal muscle. Developmental changes in NCX1 and NCX3 as well as the distribution of these isoforms at the cellular level and in different fiber types suggest that they may have different physiological roles.