[PRRT2 mutation and infantile convulsions]. / Faut-il toujours traiter les convulsions infantiles liées à une mutation de PRRT2 ?

New genetic techniques have made it possible to better understand the implications of the PRRT2 gene (proline rich transmembrane protein 2) in various neurological disorders. Mutations within this gene are responsible for kinesigenic paroxysmal dyskinesias (PKD) as well as for benign familial infantile epilepsy (BFIE), a disease associating infantile convulsions and choreoathetosis (ICCA), a form of familial hemiplegic migraine (FHM type 4), paroxysmal benign torticollis of childhood, and episodic ataxia. We describe the case of an infant, carrying a mutation of the PRRT2 gene, with a classical presentation. Through her progression over time, we raise the question of systematic use of anti-epileptic drugs.

Gafchromic film dosimetry: four years experience using FilmQA Pro software and Epson flatbed scanners.

PURPOSE: s: To assess performance of FilmQA Pro software for pre-treatment patient-specific quality assurance (QA), using radiochromic films and two commercial flatbed scanners. To evaluate a novel multichannel approach compared to the classical red channel evaluation. MATERIAL AND METHODS: Patient films (mostly EBT2 films, one box of EBT3) were digitalized using successively two flatbed scanners: the A4-size Epson V750 and the A3-size Epson 10000XL. Prior to patient dose verification, basic characteristics of films and scanners were investigated. Patient films were analyzed using FilmQA Pro software, which enables to use the signal from all three colour channels (Red, Green, Blue). RESULTS: Compared to the red channel evaluation, multichannel evaluation presents better passing rates with regard to local gamma index. As expected, we obtained better results using A3-size scanner compared to A4-size scanner, especially when considering large region of interest. An observation of great interest was made for both scanners: after intensive use, a tilting in the blue transmittance profiles appeared in the lamp direction, making multichannel analysis unsuitable for accurate dose evaluation.

[Technological innovations in radiation oncology require specific quality controls]. / Innovations technologiques d'irradiation et réalisation de contrôles qualité spécifiques.

During the last decade, the field of radiotherapy has benefited from major technological innovations and continuously improving treatment efficacy, comfort and safety of patients. This mainly concerns the imaging techniques that allow 4D CT scan recording the respiratory phases, on-board imaging on linear accelerators that ensure perfect positioning of the patient for treatment and irradiation techniques that reduce very significantly the duration of treatment sessions without compromising quality of the treatment plan, including IMRT (Intensity Modulated Radiation Therapy) and VMAT (Volumetric Modulated Arc therapy). In this context of rapid technological change, it is the responsibility of medical physicists to regularly and precisely monitor the perfect functioning of new techniques to ensure patient safety. This requires the use of specific quality control equipment best suited to these new techniques. We will briefly describe the measurement system Delta4 used to control individualized treatment plan for each patient treated with VMAT technology.

Early skin sensitization to aeroallergens.

BACKGROUND: Early detection of aeroallergen sensitization is important as a prognosis factor but may be more difficult in young children. OBJECTIVE: We sought to demonstrate that skin sensitization to aeroallergens was present in a selected group of 0-2-year-old children and that it was associated with environmental exposure and a family history of allergic disease. METHODS: Data on exposure and history were extracted from the files of 824 children seen in the asthma clinic and who were skin tested to a panel of aero- and food allergens. RESULTS: Forty percent of our children demonstrated atopy, 28% were sensitized to aeroallergens, the majority of which to house dust mite. Higher sensitization rates were found in children with large weals to histamine (P<0.001) and in those who slept with soft toys [odds ratio (OR) 1.45, 95% confidence interval (CI) 1.02-2.08]. With a definition of sensitization including the size of the weal to histamine, there was a negative association with a personal history of eczema only (OR 0.66, 95% CI 0.45-0.99). There was no gender-dependent effect and no association with day-care attendance. CONCLUSION: This is one of the largest studies to evaluate skin testing in a selected population of young children. We found a high prevalence of sensitization to aeroallergens, which was associated with exposure to soft toys. Further follow-up of this population will allow assessment of the predictive value of this sensitization.

[Asthma in the young child: when should inhaled foreign body be suspected?]. / Asthme du jeune enfant: quand évoquer un corps étranger endobronchique?

Many young children and infants wheeze during viral infections of the respiratory tract. The differential diagnosis of those children includes the inhalation of a foreign body. This diagnosis is overlooked in about 20% of cases, which leads to subacute and chronic complications. Two clinical observations are reported, involving young children with clinical asthma exacerbations but where the absence of response to usual treatment and/or the absence of evidence for atopy and/or the acute onset brought us to suspect the inhalation of a foreign body. These cases allow us to remind the usual signs and symptoms associated with the inhalation of a foreign body. Amongst these signs, unilateral hypoventilation on chest auscultation associated with localized emphysema on chest x-ray has a very high positive predictive value. Aggressive management in a specialized surrounding is advocated when an inhaled foreign body is suspected. Algorithms based on the level of suspicion have been designed to allow the pediatric respiratory physician to choose between rigid and fiberoptic bronchoscopy. It is only by systematization of these procedures and development of preventive measures that we will be able to reduce the prevalence of complications secondary to the inhalation of a foreign body.

Effects of DNA polymer length on its adsorption to soils.

Three different DNA fragments ranging size from 2.69 kbp (1.75 MDa) to 23 kbp (14.95 MDa) were used as tracers to study the adsorption of polydisperse solutions of calf thymus DNA to eight model soils. The adsorption of the three tracers to all soils was described by the Freundlich adsorption model, with adsorption coefficients (K) ranging from 1.1 for acid-washed sand to over 300 for one soil. An inverse relationship between tracer size and K was observed with six of the eight soils, indicating that smaller fragments are sorbed preferentially versus larger fragments in these soils. No significant correlation between K and the organic carbon contents, clay contents, pHs, or cation exchange capacities of the model soils was observed.