Translation and validation of the PVSQ and DHI-PC questionnaires for pediatric dizziness.

AIMS: Validation of the PVSQ self-report questionnaire (diagnosis) and the DHI-PC caregiver report questionnaire (Dizziness Handicap Inventory) aims to improve the management of pediatric vertigo, which is often under-diagnosed. MATERIALS AND METHODS: The PVSQ and DHI-PC questionnaires were translated according to the Forward-Backward method and presented to a group of patients consulting for dizziness in a referral center and to a control group. A retest was performed at 2weeks for both questionnaires. Statistical validation consisted in calculating discriminatory capacity, ROC curve, reproducibility and internal consistency. The main study objective was the translation and validation of the PVSQ and DHI-PC questionnaires in French. The secondary objectives were to compare results in two subgroups according to the vestibular or non-vestibular etiology of dizziness and to assess the correlation between the two questionnaires. RESULTS: In total, 112 children, in two comparable groups (53 cases and 59 controls), were included. Mean PVSQ score was 14.62 for cases and 6.55 for controls (P<0.001). Reproducibility was moderate, and internal consistency and construct validity were satisfactory. A cut-off of 11 corresponded to maximum Younden index. Mean DHI-PC score was 41.6 (cases only). Reproducibility was moderate, and internal consistency and construct validity were satisfactory. CONCLUSION: The validation of the PVSQ and DHI-PC questionnaires offers two new tools in the management of dizziness, for both screening and follow-up.

Large uniform-sized polymer beads for use as solid-phase supports prepared by ascension polymerization.

Large uniform-sized polymer beads are desirable for "one-bead-one-compound" applications in the combinatorial synthesis of compound libraries. We have developed a technique for the preparation of large polymer spheres with narrow size distributions. Uniform-sized poly(styrene-co-divinylbenzene) beads with diameters in excess of 1 mm have been prepared by free radical polymerization in an ascension process through a heated column. The size of the beads can be adjusted by the diameter of the injection needle and the injection speed. The resin beads can be made porous by the incorporation of a porogen during the preparation; they reach a specific surface area in excess of 200 m(2)/g. The mechanical properties of the spheres and their use in organic synthesis have been studied.

Prevalence of asthma and rhinitis in relation to long-term exposure to gaseous air pollutants.

The relationship between long-term exposure to air pollutants, especially with regard to photochemical air pollutants, and asthma prevalence in developed countries is controversial. The objective of this cross-sectional survey was to compare mean levels of the main gaseous air pollutants and prevalence rates of rhinitis, asthma, and asthmatic symptoms. It included 2,445 children from the 8th and 9th school grades who had been living for at least 3 years in an area where some communities undergo the heaviest photochemical exposure in France. Data on rhinitis, asthmatic symptoms, and asthma prevalence were gathered with the ISAAC paper and video questionnaires. The relation between level of air pollutants and asthma was assessed first by comparison of crude prevalence rates (chi-square test), and then by simple regression analysis and multiple logistic regression analysis. No consistent association between mean SO2 and NO2 levels, and prevalence of rhinitis, asthma, or asthmatic symptoms could be demonstrated. In contrast, there were statistically significant associations between prevalence of asthmatic symptoms and mean ozone O3) concentration. The interpretation of such findings is not straightforward, as these symptoms can be interpreted either as respiratory irritation due to exposure to nonspecific airway stimuli or as a true asthmatic state. Additional studies are required to clarify this important issue. In conclusion, this large cross-sectional epidemiologic survey performed in an area of high photochemical air pollution did demonstrate statistically significant associations between the prevalence of asthmatic symptoms and mean O3 concentration.

[Convulsions and neonatal hypoparathyroidism revealing maternal hyperparathyroidism]. / Convulsions et hypoparathyroïdie néonatales révélant une hyperparathyroïdie maternelle.

BACKGROUND: Severe prolonged hypocalcemia may occur in neonates whose parathyroid hormone production has been blocked by maternal hyperparathyroidism. This report describes such a case. CASE REPORT: A 7 day-old girl was admitted suffering from dyspnea and repeated convulsions that had continued for 2 days. Her birthweight was 3,500 g and her height 50 cm. Her mother had been given an iron preparation and calcium during pregnancy. Clinical examination of the newborn at birth revealed a cleft palate and micrognathia. The baby had been given milk-formula plus ergocalciferol, 1,200 IU/day. At admission, the baby was hypotonic. Her serum total calcium was 1.27 mmol/l; total proteins 61 g/l; ionized calcium 1.1 mmol/l; phosphorus 2.14 mmol/l; intact PTH 21 pg/ml (N = 10-65) and 25(OH)D 8 ng/ml (N = 8-30). She was given intravenous calcium gluconate (1 g/m2/d), diazepam (0.5 mg/kg) rectally, intravenous phenobarbital (20 mg/kg) but intravenous phenytoin was needed to stop clinical and electrical seizures. Her blood calcium was normalized 5 days later. Her mother, who was clinically normal, had: total serum calcium: 2.72 and 2.77 mmol/l; total proteins: 71 g/l; phosphorus: 0.85 mmol/l; intact PTH: 73 pg/ml; 25(OH)D: 6 ng/ml; Ultrasonography showed an adenoma of the right parathyroid. Further studies on the baby showed no signs of Di George syndrome. CONCLUSION: Neonatal hypocalcemia always requires investigation of both the infant and mother. Measurements of vitamin D metabolites and intact PTH are required to recognize maternal hyperparathyroidism.

Structure of a psoralen derivative of a monosubstituted 18-crown-6 ether.

N-[(2,5,9-Trimethyl-7-oxo-7H-furo[3,2-g]-[1] benzopyran-3-yl)methyl]-1,4,7,10,13,16-hexaoxacyclooctadecane- 2,3-dicarboximide, C29H35NO11, Mr = 573.60, monoclinic, P21, alpha = 18.877 (9), b = 6.888 (6), c = 24.488 (10) angstrom, beta = 119.90 (4) degrees, V = 2760.2 angstrom3, Z = 4, Dx = 1.380 Mg m-3, lambda (Cu K a) = 1.54178 angstrom, mu = 0.85 mm-1, F(000) = 1216, T = 170 K, R = 0.065, wR = 0.057 for 3720 observed reflections. There are two molecules (I and II) in the asymmetric unit and the 18-crown-6 part of molecule II is disordered. The psoralen moieties of the two molecules are nearly centrosymmetrically related.

Electron diffraction of synthetic polymers: the model compound approach to polymer structure.

X-ray fiber diffraction is a technique most often used to establish the structure of chemically regular crystalline polymers. However, this technique has many shortcomings. Some of them are: ambiguities regarding the choice of the space group, limited intensity data, often large diffraction spots, and overlapping intensities. Microsingle crystals of synthetic polymers, when they can be produced, happen to have dimensions that are well suited to being studied by electron diffraction. Electron diffraction data from microsingle crystals often complement the X-ray fiber data. Strictly speaking, one does not solve the crystal structure of a polymer in the conventional way but rather one chooses from among many potentially acceptable models the one which fits the X-ray and/or the electron diffraction data best. The various steps of model building, its placing within the unit cell, and structure refinement will be discussed.