[Inter- and intrafamilial expression of cleidocranial dysostosis]. / L'expressivité inter- et intrafamiliale de la dysostose cléido-crânienne.

Cleidocranial dysplasia is a bony autosomal dominant disorder, defined by late closure of fontanels and sutures, clavicular aplasia or hypoplasia and supernumerary teeth. The aim of our study was to define the CBFA1 mutations in three families with cleidocranial dysplasia and to describe the phenotype expression within and between the families. While the mutation R225Q caused a similar phenotype within one family, the mutation G146R, located in the same domain, was the cause of a variable expression between two family members. A third mutation, R190Q was responsible for symptoms not commonly associated with this disorder. The results of our craniofacial examination are in agreement with the numerous descriptions in the literature. This study accents the difficulty in establishing a clinical based diagnosis due to the wide variability.

Morphological effects produced, in vitro, by ferric oxalate treatment of enamel surfaces. A preliminary SEM study.

The morphological changes produced, in vitro, by application of ferric oxalate on enamel surfaces were examined by scanning electron microscopy. Exposure of human enamel surfaces to ferric oxalate (5.3% w/w aqueous solution or added to phosphoric or citric acid) resulted in cleaned, activated enamel surfaces and a mild etching which increased surface roughness and porosity. Deposition of crystal formations occurred in approximately 50% of the examined areas. Crystals bond firmly to the porous underlying surfaces and resist washing with 5, 10 or 20 ml of distilled water.

[The outermost enamel layer. A comparative scanning electron microscopic study]. / La couche la plus externe de l'émail. Etude comparative en microscopie électronique à balayage.

The surface of the enamel layer was scanned in teeth of some representative animal species. We studied the structural organization of enamel at the surface of the teeth and also in subsurface. The surface layer was often described as "aprismatic". But, nevertheless, in mammals, prisms often reach the surface. They are packed together almost perpendicular to the periphery. The term "aprismatic" seems inappropriate. But the surface layer is particular in both a structural, physical and chemical standpoint. Its distribution on the enamel surfaces explains the variability of the etching patterns from an area to another on the same tooth.

Crystal growth on enamel in relation to acid etching.

Crystal formation may occur during etching of enamel surfaces with phosphoric acid. In this in vitro study we observed, from a morphological standpoint, some crystals left after etching, on the surfaces, using the scanning electron microscope. More often, after water-spraying, a thin generalized precipitate remains on the surface. This precipitate may be harmful for the retention of composite resins. On few specimens we obtained needle-shaped or petal-like crystals. Crystal deposits were spread evenly, on the surface, or nucleated from different points. We tempted to identify these crystal formations by X-ray diffraction and microprobe analysis. Chemical identification seems very important because calcium phosphates solubility varies. Crystal dissolution in saliva can lead to marginal leakage and impairs the quality of esthetic restorations. On the contrary insoluble crystals may ensure microscopic retentions and crystal growth is now considered as an alternative for enamel pretreatment in bracket bonding. Crystal formation, in these first experiments, is too scarce to be used for crystal bonding. But it appears that two factors may enhance the crystal number: a preliminary topical application of fluoride and adsorption of an acidic protein, on the surface, before etching. However, further investigations are still necessary.

[Semiquantitative in vitro study of the etching of human enamel: scanning electron microscopy observations]. / Etude semi-quantitative in vitro du mordançage de l'émail humain: observations au microscope électronique à balayage.

The efficiency of etching using lactic, citric, hydrochloric and phosphoric acids has been studied with the scanning electron microscope on 557 human enamel surfaces. A semiquantitative assessment has been performed with reference to Silverstone et al.'s classification (1975) as regards the demineralization stages of enamel prisms and to Sheykholeslam and Buonocuore's 6 points scale as regards the etching degrees. Lactic and citric acids proved ineffective. Hydrochloric and phosphoric acids were efficient between 20 and 50% concentrations. A 1 minute etching seems optimal. A long-continued etching induces crackling of the surface enamel layer into patches which do not stick properly to the underlying enamel. Only the removal of the hypermineralized surface layer (using a diamond wheel) allows to obtain microporosities evenly distributed all over the sample surface. A mechanical treatment of enamel surfaces prior to etching is necessary especially when temporary teeth or "mature" (between 5 and 50) or "aged" (over 50) teeth are concerned.

Antinuclear antibodies detected by indirect immunofluorescence on HEp2 cells and by immunoblotting in patients with systemic sclerosis.

The HEp2 cell cultures appeared highly sensitive in detecting the antinuclear antibodies (ANAb) in systemic sclerosis, principally anticentromere antibodies of the CREST syndrome. The immunoblotting used with either complex cellular extracts from HeLa and rabbit thymus or purified nuclear components (high mobility group (HMG) proteins and histones) is able to identify precisely the ANAb targets and to contribute to diagnosis. With nuclear extracts of HeLa cells, the sera from 75.8% of CREST syndrome subjects stained 18 and 22 kD proteins. Corresponding antibodies were also detected in 72.7% of these patients, on HEp2 centromers by indirect immunofluorescence. With the same extracts, 33.3% of sera from diffuse sclerosis/acrosclerosis patients contain antibodies staining 86, 73, 32 and 30kD. These sera also stain 77, 66 and 63kD from thymus extracts. Corresponding antibodies will be the anti-SCL-70 antibodies defined by double immunodiffusion. The anti-HMG antibodies were infrequent in systemic sclerosis, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) and consequently without interest for diagnosis. The anti-whole histones antibodies which are less frequent in diffuse sclerosis/acrosclerosis (35.7%) than in SLE (41.3%) recognize especially H1 and H2A in the first diseases, H1 and H2B in SLE and H1 and H3 in RA.

Scanning electron microscopy of molar enamel structure of cricetodontine neogene rodents.

Ultrastructural characters of enamel were studied as a phylogenetic indicator in a family of rodent fossils: the Cricetidae. The extinct group Cricetodon-Ruscinomys is a known lineage which span 17 million of years (from -20 My to -3 My). The three-dimensional organization of enamel of the left M1 was studied in 8 cricetid species at three different levels: (1) the chewing surface; (2) the middle of the crown; (3) the cervical part, close to the root. The arrangement and other details of enamel prisms varied according to five factors: (1) tooth morphology (there were differences between the four faces of the same molar); (2) enamel thickness; (3) level of crown; (4) degree of hypsodonty; (5) chronological age of the extinct species.

[Low colorectal anastomosis by the anterior perineal approach. 29 cases]. / Anastomoses colo-rectales basses par voie périnéale antérieure. Vingt-neuf observations.

Using the combined abdominoperineal approach to the rectum through the recto-genital space, very low colo-rectal anastomosis can be performed without damaging the anal sphincter. Twenty-nine patients were operated upon by this procedure for malignant or benign disease of the lower two-thirds of the rectum: there was 2 failure; 6 patients developed transient perineal fistula; 27 patients now have normal anal continence. This technique has been considerably facilitated, notably in males, by stapled anastomosis.

[Cystohepatic ducts. Surgical problems and review of the literature. About 10 operated cases (author's transl)]. / Les canaux cysto-hépatiques. Incidences chirurgicales et revue de la littérature. A propos de dix cas opérés.

The authors are reporting 10 cases of operated cystohepatic ducts. In each case there is a unic duct, leading five times in the gallbladder, and once in the cystic duct. In 8 cases this abnormality was shown intraoperatively. In 2 cases the diagnosis was only given during the surgical procedure, when a fistulography was performed. In one case it was necessary to reoperate. In four cases during the cholecystectomy we had to ligate the cystohepatic duct. In order to argue these cases, a literature review was done: 42 cases were found. The ligation of a cystohepatic duct is in most cases without consequences. the different ways of restoration are studied when large ducts are found. The best treatment of such an abnormality seems to be an anterograde cholecystectomy associated to a systematic drainage of the gallbladder region.