[Prevalence of dental caries in children before and after a prevention program in Seine-Saint-Denis]. / Prévalence de la carie dentaire chez l'enfant avant et après un programme de prévention en Seine-Saint-Denis.

BACKGROUND: The Seine-Saint-Denis Council planned in 1984 a prevention strategy program among schoolchildren which consisted in a health educational campaign and fluoridation therapy. The purpose of this paper was to present the evolution of dental caries among 11-year-old children from a low-income country after 8 years of prevention and to discuss further orientations in prevention. METHODS: Two cross-sectional surveys were conducted in 1984 and 1992 on, respectively, 1,907 and 2,771 schoolchildren attending primary schools of the department. The DMF index, summing up the total number of decayed, missing or filled permanent teeth was used to assess dentition status. RESULTS: The DMF index ranged from 3.38 in 1984 to 1.99 in 1992, a 41% decrease. This decrease was associated with a change of the distribution in DMF, the percentage of caries-free children increasing from 19% to 42% after 8 years. 83% of the decayed teeth were first molars. In 1992, only 24% of children received comprehensive care. In both surveys, the prevalence of dental caries was related to socio-economic status. CONCLUSIONS: Prevention strategy in this low-income county, led to improved dental health among children. However, the study design did not allow for evaluation of the impact of preventive measures on the evolution of dental caries prevalence. The community program contributed to improved dental health in most children even if it could not prevent the development of dental caries in very low-income children with severely decayed teeth and no access to dental care. Further steps in order to improve prevention, including use of sealants among these children, are under evaluation.

Interaction between G-actin and various types of liposomes: A 19F, 31P, and 2H nuclear magnetic resonance study.

We have investigated in the present study the interaction between G-actin and various types of liposomes, zwitterionic, positively charged, and negatively charged. To investigate at the molecular level the conformation of actin in the presence of lipids, we have selectively attached a fluorinated probe, 3-bromo-1,1,1-trifluoropropanone, to the actin cysteine residues 10, 285, and 374 and used high-resolution 19F nuclear magnetic resonance spectroscopy to investigate the probe resonances. The results indicate a change in the mobility of the 19F labels when G-actin is in the presence of positively charged liposomes made of DMPC and stearylamine and in the presence of DMPG, a negatively charged lipid. No conformational change was observed in the actin molecule in the presence of neutral liposomes. Electron micrographs of these systems reveal the formation of paracrystalline arrays of actin filaments at the surface of the positively charged liposomes, while no evidence of actin polymerization or paracrystallization was observed in the presence of DMPG. The interaction between actin and the lipid polar headgroup has also been investigated using solid-state phosphorus and deuterium NMR. The results indicate no evidence of interaction between actin and zwitterionic liposomes but show an interaction between the positively charged liposomes and a negative charge on the actin molecules. Interestingly, the negatively charged liposomes interact with a positive charge, which is most likely associated with the three residues (His-Arg-Lys) preceding the cysteine 374 residue in the protein.

Bone scan in systemic amyloidosis.

Thirty patients diagnosed as having systemic amyloidosis (six with primary amyloidosis and 24 with secondary amyloidosis) were given bone scans with 99Tcm-methylene diphosphonate in order to evaluate the skeletal and extra-osseous uptake and their clinical-scintigraphic correlation. Extra-osseous uptake appeared in nine instances, more frequently in primary (5/6) than in secondary (4/24) amyloidosis. Fourteen patients had clinical and echocardiographic suspicion of cardiac amyloidosis but only one showed cardiac uptake. Six patients had probable hepatic involvement but in only two cases was hepatic uptake seen. The extra-osseous uptake suggests the presence of amyloid deposits in the organs and soft tissues which take up the bone tracer. The absence of any uptake does not rule out amyloid infiltration.

Brain amine concentrations after monoamine oxidase inhibitor administration.

The concentrations of 5-hydroxytryptamine (5HT), noradrenaline, and dopamine were estimated post mortem in brain stem, hypothalamus, and caudate nucleus in 33 patients who had been treated with isocarboxazid, clorgyline, or tranylcypromine and 11 controls. Similar and highly significant increases in 5HT and noradrenaline concentration occurred with all three drugs. The distribution was unimodal, but about a quarter of the patients showed only a small increase in brain amines. Tranylcypromine seemed to have a significantly greater effect on dopamine in caudate nucleus and hypothalamus compared with isocarboxazid and clorgyline. In the doses used chlorpromazine did not reduce the amine concentrations. Four patients with Parkinson's syndrome had low concentrations of dopamine in caudate nucleus in spite of monoamine oxidase inhibitor administration.