Assessment of the severity of hereditary spherocytosis using routine haematological data obtained with dual angle laser scattering cytometry

Dual angle laser scattering cytometry (DALC) measures erythrocyte volume and haemoglobin concentration directly and provides spherocyte quantification. We have studied DALC red cell features in hereditary spherocytosis (HS) relating them to the clinical severity of the illness. A total of 140 controls and 80 non-splenectomized HS cases were studied, with mild (n = 32), moderate (n = 37) and severe (n = 11) disease. DALC measured mean corpuscular haemoglobin concentration, percentage of erythrocytes with haemoglobin concentration over 410 g/l (%Hyper), red cell volume and haemoglobin concentration distribution widths were significantly different in HS cases when compared to controls (P < 0.001). Severe HS cases had more heterogenous erythrocyte populations, both in volume and haemoglobin concentration (P < 0.001). Clinical severity of HS was best reflected by erythrocyte volume distribution width followed by %Hyper. DALC red cell features are both a diagnostic tool and an index to the severity of HS.     

Factors affecting dental fear in French children aged 5–12 years

International Journal of Paediatric Dentistry 2010; 20: 366–373 Background. While dental anxiety is often correlated with prior negative dental experience, prevention of dental anxiety should in theory include early exposure to the dental setting. Objective. We set out to evaluate factors affecting dental fear in French children. Methods. Dental fear was evaluated using a visual analogue scale (DF‐VAS) in a group of 1303 French children (681 boys and 622 girls) aged 5–11 years (mean: 8.12 years, SD: 1.42 years). Indicators of caries and oral hygiene were evaluated on dental examination. Indicators of well‐being related to oral health, dental experience, and oral health education were collected via a structured interview. Results. Dental fear was scored low in 75.7% (DF‐VAS 0–3), moderate in 16.7% (DF‐VAS 4–6), and high in 7.6% (DF‐VAS 7–10). DF‐VAS decreased statistically with experience of a prior dental visit. Children who had at least one decayed tooth presented a higher level of dental fear than those with no decay, while children with fillings were significantly less anxious than those without previous dental care. Conclusions. This study shows that for children aged 5–12 years, prior experience of the dental setting can act as a positive component of dental fear.     

Usual sleep duration and cognitive function in older adults in Spain

The few studies that have examined the association between usual sleep duration and cognitive function have shown conflicting results. This cross‐sectional study examined the association between sleep duration and cognitive function among 3212 people, representative of the non‐institutionalized population aged 60 years and over in Spain. Sleep duration was self‐reported, and cognitive function was measured with the Mini‐Examen Cognoscitivo (MEC), a version of the Mini‐Mental State Examination that has been validated in Spain. Linear regression, with adjustment for the main confounders, was used to obtain mean differences in the MEC between the categories of sleep duration (≤5, 6, 7, 8, 9, 10, ≥11 h day^?1). The MEC score decreased progressively (became worse) across sleep categories from 7 to ≥11 h (P for linear trend <0.001). People who slept for ≥11 h had a significantly lower MEC score than those who slept for 7 h (mean difference ?1.48; 95% confidence interval ?2.12 to ?0.85). This difference in the MEC was similar to that observed for a 10‐year increase in age. The results did not vary significantly by sex (P for interaction >0.05). No association was observed between short sleep duration (<7 h) and cognitive function. We conclude that long sleep duration is associated with poorer cognitive function in older adults from the general population.     

Predicting the Solubility of Drugs in Solvent Mixtures: Multiple Solubility Maxima and the Chameleonic Effect

Abstract— An approach to reproduce the solubility profile of a drug in several solvent mixtures showing two solubility maxima is proposed in this work. The solubility of sulphamethoxypyridazine was determined at 25°C in several mixtures of varying polarity (hexane: ethyl acetate, ethyl acetate:ethanol and ethanol: water). Sulphamethoxypyridazine was chosen as a model drug because of its proton-donor and proton-acceptor properties. A plot of the mole fraction of the drug vs the solubility parameter of the solvent mixtures shows two solubility peaks. The two peaks found for sulphamethoxypyridazine demonstrate the chameleonic effect as described by Hoy and suggest that the solute-solvent interaction does not vary uniformly from one mixture to another. The different behaviour of the drug in mixtures of two proton-donor and proton-acceptor solvents (alcohol and water), and in mixtures of one proton acceptor (ethyl acetate) and one proton donor-proton acceptor (ethanol) is rationalized in terms of differences in the proton donor-acceptor ability of the solvent mixtures. An approach based on the acidic and basic partial solubility parameters together with the Hildebrand solubility parameter of the solvent mixtures is developed to reproduce the experimental results quantitatively. The equation predicts the two solubility maxima as found experimentally, and the calculated values closely correspond to the experimental values through the range composition of the solvent mixtures. These results show that the chameleonic effect can be described in a quantitative way in terms of Lewis acid-base interactions; this approach can assist the product formulator to choose the proper solvent mixture for a new drug. A good solvent blend should result in a solubility parameter close to that of the drug; the acidic and basic partial solubility parameter values should provide maximum acid-base interaction of the mixed solvent with the drug. The failure in one of these conditions results in decreased solubility. Solubility parameters as well as the acidic and basic parameters are tabulated or they can be obtained from group contribution methods, making easier the evaluation of the best solvent mixture for a drug.     

The prevalence of childhood asthma in Costa Rica

The prevalence of asthma in children between the ages of 5 and 17 years in Costa Rica was determined using a large sample (n = 2682). The definition of asthma was based on a combination of a physician's diagnosis and a symptom score, using information from a questionnaire given to the parents. An overall asthma prevalence as high as 23·4% was found. Sex, age, urban/rural location, or rain precipitation did not show any association with the diagnosis of asthma. The presence of smokers in the home was found to be an important risk factor (odds ratio = 1·6). Another identified risk factor was a high yearly average outside temperature, i.e. above 25°C (odds ratio = 1·8). Furthermore, the proportion of children with more than four upper respiratory infections during the preceding year was found to be significantly increased in children with asthma (odds ratio = 4·3). The non-asthma group seemed to use equal amounts of drugs for the treatment of asthma as the asthma group. For a country like Costa Rica with limited economic resources the current work indicates two important issues for consideration in the future; firstly, to try to define the cause(s) of asthma and secondly, to continuously inform the physicians about the best way of diagnosing and treating asthmatic patients to ensure optimal handling of this large patient group.