A two-year prospective study of the health-related quality of life of children with chronic illness--the parents' perspective.

The aim of this study was to assess prospectively changes in the health-related quality of life (HRQL) of children and adolescents with diabetes, asthma or cystic fibrosis (CF). One hundred and twenty-two parents of children aged 10-16 years with asthma, diabetes, or CF were recruited from specialist paediatric clinics. Parents described their children's HRQL using the Child Health Questionnaire (PF98) at baseline, 6, 12, 18 and 24 months post-baseline. They reported that the general health of children with CF was significantly worse than that of children with asthma and diabetes at baseline. In other domains there were few differences between the HRQL of children in the three groups. In several domains, the HRQL of children with asthma or diabetes improved over the 2 years of the study. This improvement was less evident for children with CF.

Demonstration of a bilateral projection from the rostral nucleus of the solitary tract to the medial parabrachial nucleus in rat.

This study examined the projection from the rostral nucleus of the solitary tract (rNST) to the medial parabrachial nucleus (mPBN) in male Wistar rats using DiI as a retrograde tracer and biotinylated dextran as an anterograde tracer. Following successful unilateral injection of DiI into the mPBN (n = 8), retrogradely labeled neurons were always found in the rNST both ipsilateral and contralateral to the pontine injection site. Significantly, approximately 25% of the total number of DiI-labeled neurons were located in the contralateral rNST. The labeled neurons were located throughout the rostral-caudal extent of the rNST with the most cells being located in the central portion of the nucleus, and the fewest located ventromedially and dorsolaterally. Supporting the findings of the retrograde labeling study, axons and terminals, anterogradely labeled by injecting biotinylated dextran unilaterally into the rNST (n = 4), were always found in both the ipsilateral and contralateral mPBN. Although the intensity of anterograde labeling was higher ipsilaterally, a mirror-image staining pattern consistently was present contralaterally. These results indicate that there is a substantial contralateral component of the projection from the rNST to the mPBN. This suggests that convergence of gustatory information from the two sides of the oral cavity may occur within the pons before processing in higher brain centers. These findings may have important implications as to where and how bilateral gustatory information is processed and integrated.

Plasma and developing enamel fluoride concentrations during chronic acid-base disturbances.

Mild acid-base disturbances were induced in rats for 30 days. These disturbances did not affect % ash of maxillary incisors or % P of the developing enamel from mandibular incisors. Total fluoride intake (food and water) among groups drinking fluoride-free water was constant. Nevertheless, average plasma and developing enamel fluroide concentrations were highest in the acidotic group and lowest in the alkalotic group. Among groups drinking water containing 50 ppm fluoride, total fluoride intake was highest by the alkalotic group and lowest by the acidotic group. Plasma and enamel fluoride concentrations, however, were highest in the acidotic group. It is concluded that plasma and developing enamel fluoride levels can be independent of, or inversely related to, fluoride intake.

Fluoride tissue distribution: short-term kinetics.

The short-term distribution kinetics of 18F, with and without added carrier, were studied in 12 soft tissues and femur following intravenous administration in rats. The animals were killed in groups of four at 5, 10, 15, 20, 30, and 60 min after the dose. A tissue was judged to be kinetically homogeneous with plasma if an early and constant tissue water-to-plasma (T/P) 18F concentration ratio was established. In the carrier-free study, liver, heart, skin, fat, and kidney met this criterion. In the presence of carrier, four other tissues were added to this group. Brain, resting skeletal muscle, spleen, and femur did not achieve constant T/P values. The addition of carrier resulted in significantly lower T/P ratios in nine tissues. This was especially marked in femur. It is concluded that 1) none of the soft tissues studied strongly binds 18F; 2) most of these tissues are kinetically homogeneous with plasma; and 3) the presence of carrier fluoride can significantly influence the kinetic behavior and distribution of 18F. Finally, based on the current and previously reported 18F T/P ratios, and on reported intracellular-extracellular pH gradients, it is hypothesized that fluoride distribution in several soft tissues is determined by the diffusion equilibrium of HF, that is, by the magnitude of the transmembrane pH gradient.

Distribution of 14C-formaldehyde after pulpotomy with formocresol.

Pulpotomies were performed on rhesus monkeys with use of formocresol to determine if there was uptake of 14C-formaldehyde into the systemic circulation after formocresol pulpotomies. Five-minute exposure of pulpal tissue to the 14C-formocresol resulted in the systemic absorption of approximately 1% of the dose. Two hours of exposure of pulp tissue to the 14C-formocresol did not increase the systemic absorption. Multiple sequential pulpotomies resulted in proportionately higher systemic absorption of 14C-formaldehyde. Application of 131I to pulpotomy sites indicated that formocresol compromises the microcirculation of the dental pulp. Autoradiography disclosed extensive concentrations of 14C-formaldehyde in the pulp, dentin, periodontal ligament, and bone.

Blood and urinary 18F pharmacokinetics following parenteral administration in the rat.

Blood and urinary excretion time courses of 18F administered parenterally to rats were monitored for two hours. The intraperitoneal, subcutaneous, and intravenous routes gave kinetically indistinguishable results after ten minutes following the dose. The blood time course during the first hour following intramuscular dosing showed a relative constancy and suggested a delayed absorption time.

Fluoride absorption from the rat urinary bladder: a pH-dependent event.

Urinary bladder absorption of stable and radiofluoride was studied as a function of pH in anesthetized rats to further evaluate the influence of pH gradients on fluoride transport. Buffered pH values and stable fluoride concentrations ranged from 1.85 to 7.90 and from 0.012 to 8.81 mM, respectively. [14c]inulin served as a marker for solute concentration changes due to water migration or dilution. The results indicate that bladder fluoride absorption is inversely related to pH over the 1.85-5.50 range. Mean, 15-min radiofluoride absorption values of 70% at pH 1,85, 37% at pH 3.95, and 5% at pH 5.50 WERE OBSERVED. These fractional absorption values were not significantly influenced by carrier fluoride concentration, the buffers used, or the presence of urine. Above pH 5.50, pH-independent absorption occurs to a slight extent. The results are consistent with a first-order absorptive process which occurs by the nonionic diffusion of hydrogen fluoride.