Identifying problematic severe asthma in the individual child--does lung function matter?

AIM

Measures of lung function (usually FEV(1) <80% predicted) are used to classify asthma severity in both adults and children, despite evidence that lung function impairment is less pronounced in the paediatric asthma population. The present study assesses the relevance of lung function measurements as discriminators of severe childhood asthma.

METHODS

Fifty-one school-aged children with problematic severe asthma, 37 mild-to-moderate asthmatics and 29 healthy controls underwent a comprehensive clinical work-up. Problematic severe asthma was defined in patients exhibiting poor asthma control despite high-dose inhaled corticosteroid treatment and at least one other asthma controller drug. Mild-to-moderate asthmatic children used low-dose inhaled steroids and reported minimal asthma symptoms.

RESULTS

Baseline FEV(1) values were significantly reduced in children with problematic severe asthma, yet FEV(1) <80% predicted showed a low sensitivity (41%) for discriminating severe vs. mild-to-moderate asthma. Receiver-operated characteristic analysis estimated the optimal cut-off of FEV(1) to be 90% predicted in this population (sensitivity 61%, specificity 83%). Baseline FEV(1)/FVC and FEF(25-75) values were not superior to FEV(1) in discriminating problematic severe asthma, and neither exhaled nitric oxide levels nor bronchial hyperresponsiveness differentiated between the two asthmatic study populations.

CONCLUSION

Spirometric measurements are insensitive discriminators of problematic severe asthma in childhood.

Biotransformation of insulin glargine after subcutaneous injection in healthy subjects

OBJECTIVE

It is important to establish pharmacokinetic or pharmacodynamic differences between novel insulin analogues and human insulin. This study examined the primary metabolic degradation products of insulin glargine (LANTUS) in humans.

DESIGN

In this single dose, open-label study, insulin glargine was administered subcutaneously at a dose of 0.6 IU/kg; placebo was administered to one control subject.

PATIENTS

Four healthy male subjects, plus one control subject, aged 18-50 years were enrolled in this study.

MEASUREMENTS

Following insulin glargine administration, blood glucose levels were clamped at the subjects' fasting concentration for 6 h and the amount of 20% glucose infused to maintain this baseline concentration was recorded. Metabolite profiling was performed in plasma and injection site tissue using HPLC and radioimmunoassay (RIA). Pharmacokinetics were evaluated by RIA of serum and plasma immunoreactive insulin levels. The primary pharmacodynamic measure was the glucose infusion rate (GIR). Safety was evaluated by measuring blood glucose concentrations during the clamp and adverse events were observed by the investigator or reported by the subject.

RESULTS

Metabolic profiling revealed a clear pattern: insulin glargine is metabolised by sequential cleavage at the carboxy terminus of the B chain, to yield products M1 and M2, which are both structurally similar to human insulin. These degradation products are present both at the injection site and in plasma.

CONCLUSION

Thus, during treatment with a subcutaneous injection of insulin glargine, metabolic degradation is likely to be initiated at the injection site and continued within the circulatory system.

Clinical evaluation of the Gen-Probe Amplified Direct Test for detection of Mycobacterium tuberculosis complex organisms in cerebrospinal fluid

Eighty-four cerebrospinal fluid (CSF) samples from different children who presented with signs and symptoms of meningitis were evaluated for the presence of Mycobacterium tuberculosis complex organisms by the Gen-Probe Amplified Mycobacterium tuberculosis Direct Test (MTD; Gen-Probe, San Diego, Calif.). All CSF samples had negative acid-fast smears by the Ziehl-Neelsen staining method. M. tuberculosis was recovered from five samples. M. tuberculosis did not grow from 19 additional samples, but the samples were from patients who fulfilled specific clinical and laboratory criteria for probable tuberculous meningitis (TBM). The remaining samples (n = 60) were from patients with other infections or noninfectious causes of meningitis. The results of the MTD were interpreted as positive or negative on the basis of recommended cutoff values for respiratory specimens. These results were interpreted as true or false positives or true or false negatives on the basis of the results of M. tuberculosis culture or whether the patient fulfilled criteria for probable TBM. The Gen-Probe MTD was 33% sensitive and 100% specific for detecting M. tuberculosis complex organisms in these 84 CSF samples. If the cutoff values for positive results were decreased for the MTD (> or = 11,000 versus > or = 30,000 relative light units), the sensitivity increased to 83% and the specificity remained 100%. These results for the MTD are encouraging considering that TBM is a highly fatal disease and difficult to diagnose by conventional laboratory techniques.

Women's changing roles and help to elderly parents: attitudes of three generations of women

Data on the effects of women's changing roles on attitudes toward responsibility for care of elderly adults were gathered from three generations of women (N = 403). Elderly women, middle-generation daughters, and young-adult granddaughters were compared on responses to Likert-scaled attitude items relating to gender-appropriate roles and care of elderly persons (including filial responsibility and acceptability of formal and informal supports). Significant generational differences occurred on attitude items relating to sharing of child care, parent care, and household tasks by men and women, but majorities of all generations were in favor of such sharing. The oldest generation was most receptive (and the youngest the least receptive) to formal services for elderly persons, but all three generations agreed that old people should be able to depend on adult children for help. Values about family care of elderly adults have not eroded despite demographic and socioeconomic changes.