Dementia,the fate of brain? Neuropathological point of viewLe destin du cerveau ? Un point de vue neuropathologique sur les démences.

The prevalence of dementia dramatically increases during ageing, and this puts a serious strain on the optimism brought by the continuous increase in life expectancy observed in most industrialised countries. Diseases that produce dementia are numerous, and the cognitive deficit results from lesions of various regions and from different mechanisms. This modulates the possible prediction, prevention and cure of dementia. Emphasis is put on the necessity of, and prerequisite for, efficient research in the field of dementia. Three paradigmatic dementing disorders are reviewed. Subacute spongiform encephalopathies (prion diseases) constitute a biological enigma and a public health concern. In Alzheimer's disease and vascular or mixed dementia, the clinical diagnosis is still imperfect, and this hinders research. Distinguishing and accurately identifying the various types of dementia is essential for understanding their mechanism and for developing efficient therapeutic strategies, preventive and curative. For such objectives, the study of human brain tissue will remain mandatory until non-invasive markers and additional models are available. Ethical reasons banish the use of cerebral biopsy and favour the promotion of autopsy.     

Stem cell therapy: medical advance or moral challenge?Thérapie cellulaire : avance médicale ou défi moral ?

My professional lifetime has seen progress in the biomedical sciences that beggars belief. This has lead to astonishing advances in the ability to prevent and treat disease and, in the developed world at least, people live longer and healthier lives than ever before. Paradoxically, this has gone hand in hand with the growth of a vocal and influential anti-science lobby that not only rejects much modern science but is also deeply suspicious of new medical interventions. The prospect of cell therapy in the near or middle future is their current target especially where the use of embryonic stem cells or of cell nuclear transfer techniques is concerned. The prospect of cell therapy is welcomed with enthusiasm by patients with genetic and degenerative diseases who hope to benefit from them. On the other hand the whole idea is regarded as repugnant by the anti-science lobby. While some of this opposition is essentially luddite in nature, there are some more persuasive arguments raised particularly to any research than uses embryonic or foetal materials. These arguments will be examined critically. The moral problems of denying the sick the hope of effective treatments have to be weighed against those seen in the development of such treatments. (This article is closely based on an already published paper. P. Lachmann, Stem cell research: why is it regarded as a threat? An investigation of the economic and ethical arguments made against research with human embryonic stem cells. EMBO Rep. 2 (3) (2001) 165–168.)     

Guide du bon usage de la TDM en médecine nucléaire. IntroductionCT good practices for hybrid nuclear medicine (SPECT/CT and PET/CT): Introduction

Nuclear medicine hybrid imaging is a technological evolution of gamma camera scintigraphy or positron emission tomography imaging methods that are now often coupled with an anatomical imaging device, essentially a CT scanner. Following a large demand from the nuclear physicians themselves, but also from the French Nuclear Safety Authority, this guide is intended for the entire nuclear medicine community to integrate both the aspects of radiation protection related to coupled CT and those related to the quality of the CT images according to the clinical context.     

Cytochrome b-based phylogeny of the Praomys group (Rodentia,Murinae): a new African radiation?Phylogénie du groupe Praomys (Rodentia,Murinae) basée sur le cytochrome b : une nouvelle radiation africaine ?

Complete cytochrome b gene sequences allows, for the first time, establishing a nearly complete phylogeny among the Praomys group sensu lato. The genera Praomys, Mastomys and Stenocephalemys appear paraphyletic. Myomys is polyphyletic and this genus name probably needs to be restricted to its type species, M. verreauxii. The genera Zelotomys and Colomys appear as sister groups. Mastomys pernanus and Malacomys verschureni nest within the Praomys group, but their generic assignation must be further clarified. The genus Heimyscus appears closest to Praomys than to Hylomyscus. The different lineages probably result from an adaptive radiation at the end of the Miocene.     

Does sulphide detoxication occur in the gills of the hydrothermal vent shrimp, Rimicaris exoculata?Y a-t-il détoxication des sulfures dans les branchies de la crevette hydrothermale, Rimicaris exoculata ?

Ultrastructural observations of the gills of the hydrothermal vent shrimp Rimicaris exoculata reveal that the epithelial cells contain numerous mitochondria clustered around unusual organelles (diameter of 0.7 to 2.5 microns) containing membrane stacks. These organelles were termed sulphide-oxidising bodies (SOBs) by structural analogy with organelles observed in the tissues of species adapted to sulphide-rich environments. Moreover, in the gills of R. exoculata, mitochondria display numerous electron-dense granules in their stroma. Such ultrastructural features suggest that sulphide detoxication may probably occur in the gills of R. exoculata. Comparable structures were also described in the gills of other hydrothermal vent species, as the alvinellid Pompeii worms that, as R. exoculata, are housing ectosymbiotic bacteria.     

Synthèse, à partir du D-galactose,d'un dérivé protégé de la célestosamine (6-amino -6,8-didésoxy-7-0-méthyl-D-érythro-D-galact o-octose), sucre de certains antibiotiques du groupe de la lincomycine

Treatment of 1,2:3,4-di-O-isopropylidene-α-D-galactopyranuronyl chloride with diazoethane gave a diazoketone that was converted with methanol in the presence of boron trifluoride into a mixture of keto-ethers. One of these keto-ethers was transformed by reduction of its oxime and N-acetylation into a blocked derivative of celestosamine, which was found to be identical with 5 prepared from a natural source, i.e. lincomycine. The properties of the other two keto-ethers are in agreement with a (D or L)-glycero-L-altro configuration (14) for one of them, and with the presence of a 3-oxetanone ring in the structure (18) of the other one.     

<Emphasis Type="Italic">Gynichthys diakidnus</Emphasis> n. g., n. sp. (Digenea: Cryptogonimidae) from the grunt <Emphasis Type="Italic">Plectorhinchus gibbosus</Emphasis> (Lacépède, 1802) (Perciformes: Haemulidae) off the Great Barrier Reef,Australia

Gynichthys diakidnus n. g., n. sp. (Digenea: Cryptogonimidae) is described from the fish Plectorhinchus gibbosus (Lacépède) (Perciformes: Haemulidae) off Heron and Lizard Islands on the Great Barrier Reef, Australia. The monotypic Gynichthys n. g. is distinguished from all other cryptogonimid genera by the combination of a fusiform body, the lack of oral spines, a forebody that occupies approximately half or more of the body length, a deeply lobed ovary, opposite to slightly oblique testes, a seminal vesicle that is confined mainly in the forebody and the presence of multiple gonotyls in the form of two small slightly muscular pores or pseudosucker-like structures in the mid-line well anterior to the ventral sucker. Bayesian inference analysis of LSU rDNA data revealed that G. diakidnus n. sp. grouped relatively distant to species of the cryptogonimid genus Oligogonotylus Watson, 1976, which also have multiple gonotyls, suggesting that the presence of multiple gonotyls is homoplasious and has thus at least evolved twice in the family. The secondary structure of the internal transcribed spacer 2 (ITS2) rDNA region was inferred for G. diakidnus using minimum free energy and homology modelling algorithms. A four helix model was inferred with helices I and IV being relatively short (<30 nucleotides) and helix three being the longest; this structure is homologous with that observed for other digeneans and eukaryotes in general.