[The Confusion Assessment Method: Transcultural adaptation of a French version]

INTRODUCTION

The Confusion Assessment Method (CAM) is a validated key tool in clinical practice and research programs to diagnose delirium and assess its severity. There is no validated French version of the CAM training manual and coding guide (Inouye SK). The aim of this study was to establish a consensual French version of the CAM and its manual.

METHODS

Cross-cultural adaptation to achieve equivalence between the original version and a French adapted version of the CAM manual.

RESULTS

A rigorous process was conducted including control of cultural adequacy of the tool's components, double forward and back translations, reconciliation, expert committee review (including bilingual translators with different nationalities, a linguist, highly qualified clinicians, methodologists) and pretesting. A consensual French version of the CAM was achieved.

CONCLUSION

Implementation of the CAM French version in daily clinical practice will enable optimal diagnosis of delirium diagnosis and enhance communication between health professionals in French speaking countries. Validity and psychometric properties are being tested in a French multicenter cohort, opening up new perspectives for improved quality of care and research programs in French speaking countries.

Expression of carbonic anhydrase II gene in early brain cells as revealed by in situ hybridization and immunohistochemistry

A mouse carbonic anhydrase (CA II) complementary(c) DNA probe was used for in situ hybridization on mouse brain cultured cells in order to follow CA II gene expression during brain development. An improved method was established using biotinated probes that resulted in a high sensitivity and an absence of background; this method could be combined with immunohistochemistry. Hypothalamic cells of embryonic day (ED) 12-14 mice were cultured for various periods. Chronologic appearance of CA II messenger(m)RNA and protein was studied. The CA II gene transcripts are detectable as early as ED 12-13, although the protein they encode is not detectable until ED 17-18. Gene expression is restricted to 0.1% of the total population. Northern blot analysis confirmed the presence of CA II transcripts in embryonic hypothalamus. At postnatal stage, the majority of glial cells express both the CA II mRNA and the protein. Our results favour the early appearance of a glial lineage in a precise area of the developing CNS. The precocity of CA II gene transcription makes in situ hybridization an invaluable approach in defining the onset of nerve cell lineages during embryonic development.

Modulation of GFAP mRNA levels following toxic lesions in the basal ganglia of the rat

GFAP mRNA levels were quantified by Northern blot analysis using a human GFAP (glial fibrillary acidic protein) cDNA probe in association with immunocytochemistry. Ten days after a unilateral lesion of substantia nigra with 6-hydroxydopamine (6-OHDA), GFAP mRNA level is increased 1.4-fold in the ipsilateral striatum; thereafter it declined continuously to reach the control level 4 months later. This effect contrasted with the lower and more sustained increase of preproenkephalin (PPE) mRNA, a marker of neuronal target of nigrostriatal pathway. Following ibotenic acid-induced neuronal degeneration of the neostriatum in the rat, we observed a sharp elevation of the GFAP transcripts (4-fold) as soon as 2 days after the lesion both in the striatum and in the substantia nigra. Whereas in the striatum GFAP mRNA level already declined at 5 days postlesion, it remained stable in the substantia nigra. In comparison GFAP immunoreactivity was slightly delayed. No obvious modification was observed in the contralateral side to the lesion whatever the denervation condition studied. Implication of these results on the understanding and the therapeutic approach of glial scarring is discussed.

Developmental expression of the glial fibrillary acidic protein mRNA in the central nervous system and in cultured astrocytes

The expression of glial fibrillary acidic protein (GFAP)-mRNA during mouse brain development and in astroglial primary cultures has been investigated by using two approaches: Northern-blot evaluation using a specific cDNA probe, and cell-free translation associated with immunoprecipitation. During brain maturation (4-56 days postnatal), the GFAP-mRNA underwent a biphasic evolution. An increase was observed between birth and day 15 (i.e., during the period of astroglial proliferation), which was followed by a decrease until day 56 (i.e., during astroglial cell differentiation). At older stages (300 days), an increase was observed, which might reflect gliosis. During astroglial in vitro development (7-32 days in culture), the GFAP-mRNA showed similar variations. An increase, observed during the period of astroglial proliferation (7-18 days), was followed by a decrease which occurred in parallel to marked changes in cell shape, cell process outgrowth, and the organization and accumulation of gliofilaments. During the same culture period (7-32 days), alpha-tubulin mRNA, which was used as an internal standard, did not vary significantly. These results show that the increase of the GFAP protein and of gliofilaments observed both in vivo and in vitro during astroglial differentiation cannot be ascribed to an accumulation of the GFAP-mRNA. It might be that more than one mechanism regulates the levels of free and polymerized GFAP and of its encoding mRNA.

Similar time course changes in striatal levels of glutamic acid decarboxylase and proenkephalin mRNA following dopaminergic deafferentation in the rat

The time course changes in levels of mRNA encoding glutamic acid decarboxylase (GAD) and proenkephalin (PPE) was analyzed in the rat striatum following unilateral lesion of substantia nigra with 6-hydroxydopamine. The levels of both GAD and PPE mRNAs increased after the dopaminergic deafferentation, reaching concomitantly a maximal twofold increase on day 25. Thereafter, the mRNA levels declined; at 4 months, the amount of PPE mRNA remained slightly elevated whereas GAD mRNA had returned to the control value, suggesting the action of a compensatory mechanism. We also observed a rise of glial fibrillary acidic protein mRNA level which reflects a reactive astrocytosis. In contrast, alpha-tubulin mRNA level remained unchanged, indicating that no significant synaptogenesis occurs in this experimental situation. No obvious modification in mRNA levels was detected in the striatum contralateral to the lesion. These results highlight the role of the modulation of gene expression in adaptive processes to dopamine deficiency in striatal efferent pathways. Its relevance to the pathophysiology of Parkinson's disease is discussed.

Identification of a human glial fibrillary acidic protein cDNA: a tool for the molecular analysis of reactive gliosis in the mammalian central nervous system

Two clones encoding human glial fibrillary acidic protein (GFAP) were isolated from a human astrocytoma cDNA library. The clones pHGFAP1 and pHGFAP2 were selected by the combined use of differential colony hybridization and hybridization-selection technique with polyclonal anti GFAP antiserum. The longer one, pHGFAP1, encompasses 3.0 kb and includes the 1.8 kb long 3' untranslated region specific to the human mRNA. Sequence data disclosed an extensive homology within the coding region of human and mouse GFAP cDNAs even in the end domains. Blot hybridization analysis of RNAs from human, rat and mouse brain revealed a single GFAP mRNA species of 3.1, 2.8 and 2.7 kb respectively and Southern blot experiments indicated that this mRNA is most probably transcribed from a unique gene. In situ hybridization performed with biotinylated probes on cultured mouse brain cells suggests both the sorting and the transport of GFAP mRNA throughout the cytoplasm and processes of the astrocytes. As a model of reactive gliosis secondary to degenerative disorders, 6-hydroxydopamine (6-OHDA) lesion of the substantia nigra in the rat was performed. GFAP mRNA increased 1.4 fold in the ipsilateral striatum on day 10 after the lesion. It then declined to the control level 4 months later contrasting with the lower and more sustained increase in preproenkephalin (PPE) mRNA. The interspecies cross-reactivity of the HGFAP probes make them useful as a tool for the molecular analysis of reactive gliosis in various experimental models.