ABSTRACT
OBJECTIVE: To investigate the usefulness of laboratory testing and thorax radiography in children, referred to the paediatrician for evaluation of recurrent wheezing. DESIGN: Retrospective. METHODS: In this study, 158 children referred for recurrent wheezing to a specialized child outpatient clinic of the Medisch Centrum Leeuwarden, the Netherlands, in the period 1 January 1994-31 December 1996, were evaluated according to a routine protocol including haemoglobin, ESR, leucocytes, immunoglobulins, sweat chloride levels and allergy testing and chest roentgenograms. It was determined whether these investigations had yielded abnormal results and whether these test results aided in confirming/rejecting the diagnosis of asthma or were helpful in clinical management. RESULTS: In 144 of the 158 (91%) children the diagnosis 'asthma' or 'recurrent wheezing' was made. Although numerous test results were abnormal they were not helpful in establishing the diagnosis. In only one child an abnormal chest radiograph was helpful (the radiograph showed infiltrative abnormalities). Tests for aero-allergy were rarely positive in children younger than 2 years; in children older than 6 years aero-allergy was found frequently, notably to dust mite (41/144). CONCLUSION: The results of this study suggest that--except for allergy testing--routine laboratory testing and chest roentgenograms are not indicated in children referred for evaluation of wheezing disorders. Aero-allergy testing may help to decide on preventive measures.
Subject(s)
Asthma/diagnosis , Bronchial Provocation Tests , Diagnostic Tests, Routine , Asthma/diagnostic imaging , Asthma/prevention & control , Child , Child, Preschool , Diagnosis, Differential , Female , Humans , Infant , Male , Radiography , Referral and Consultation , Respiratory Tract Infections/diagnosis , Retrospective StudiesABSTRACT
Intestinal neutral NaCl absorption, which is made up of brush-border (BB) Na+/H+ exchange linked to BB Cl-/HCO3- exchange, is up- and downregulated as part of digestion and diarrheal diseases. Glucocorticoids stimulate ileal NaCl absorption and BB Na+/H+ exchange. Intestinal BB contains two Na+/H+ exchanger isoforms, NHE2 and NHE3, but their relative roles in rabbit ileal BB Na+/H+ exchange has not been determined. A technique to separate the contribution of NHE2 and NHE3 to ileal BB Na+/H+ exchange activity was standardized by using an amiloride-related compound, HOE-694. Under basal conditions, both NHE2 and NHE3 contribute approximately 50% to ileal Na+/H+ exchange. Glucocorticoids (methylprednisolone) increase BB Na+/H+ exchange (2.5 times) but increase only ileal NHE3 activity (4.1 times), without an effect on NHE2 activity. Thus ileal BB Na+/H+ exchange in animals treated with glucocorticoids is 69% via NHE3. A quantitative Western analysis for NHE3 was developed, using as an internal standard a fusion protein of the COOH-terminal 85 amino acids of NHE3 and maltose binding protein. Glucocorticoid treatment increased the amount of BB NHE3. The quantitative Western analysis showed that NHE3 makes up 0.018% of ileal BB protein in control rabbits and 0.042% (2.3 times as much) in methylprednisolone-treated rabbits. Methylprednisolone treatment did not alter the amount of ileal BB NHE2 protein. NHE3 turnover number was estimated to be 458 cycles/s under basal conditions and 708 cycles/s in glucocorticoid-treated ileum. Thus methylprednisolone stimulates ileal BB Na+/H+ exchange activity only by an effect on NHE3 and not on NHE2; it does so primarily by increasing the amount of BB NHE3, although it also increases the NHE3 turnover number.
