Tumour necrosis factor-alpha and leukotriene E4 production in wheezy infants.

It is not clear why certain infants wheeze during viral upper respiratory tract infections (URTIs) but it is possible that they have a tendency to mount an exaggerated inflammatory response leading to production of mediators that induce airway narrowing. We studied nasal tumour necrosis factor-alpha (TNF alpha) and urinary leukotriene E4 (LTE4) production during infection and after recovery in 31 wheezy infants (median age 6.2 months).

Adrenal function in preterm infants.

The adrenal function of 10 preterm infants of gestational age 27-34 weeks was assessed longitudinally from measurements of excretion rates of steroid metabolites in 24-hour urine samples collected at frequent intervals for up to 80 days after delivery. The changes in steroid excretion with time in preterm infants of gestation over 28 weeks reflect involution of the fetal adrenal zone at a similar rate to term infants. These findings are consistent with the removal at birth of the inhibitory effects of oestrogen on the 3 beta-hydroxysteroid dehydrogenase enzyme.

Microcytosis, iron deficiency, and thalassaemia in preschool children.

To investigate the possible causes of an increased incidence of red cell microcytosis in Asian children, 204 Gujarati Asian children and 88 European children attending community infant welfare clinics underwent initial screening tests for determination of red cell indices. Seventy six Asian (37%) and nine European (12%) children had microcytic red cells (mean corpuscular volume less than 74 fl). Further investigation showed that 16 of the Asian children (21%) with microcytosis had thalassaemia trait (eight were heterozygous for alpha thalassaemia and eight for beta thalassaemia), and 50 (66%) had suspected iron deficiency (confirmed by a response to oral iron in 41 cases): the remaining 'microcytic' children were aged less than 2 years, when mean corpuscular volume between 70 and 74 fl may be normal.

A major role for viruses in acute childhood encephalopathy.

29 children and 3 adults with acute depression of conscious level or acute onset of focal neurological signs were studied prospectively. 3 were found to have a non-infectious cause for their illness. The presence of interferon or specific antibodies in the serum and/or cerebrospinal fluid provided evidence of active virus infection in 25 of the remaining 29 patients.

Racial differences in red cell indices.

A high prevalence of iron deficiency was found in apparently healthy Asian immigrant children in Harrow. After excluding children with overtly abnormal red cell indices, Asian and European children had identical haemoglobin values, but Asian children had much lower mean cell volume and mean corpuscular haemoglobin values and higher red blood cell values.

Immunoglobulin levels and function in pre-school children with recurrent respiratory infections.

Thirty pre-school children with recurrent respiratory infections had a higher age adjusted mean serum IgG level than their siblings or a reference group. One index child had persistently low serum IgA, but mean serum IgA and IgM levels for the index children were normal. All of the 23 index children and 17 siblings studied had a four-fold or greater rise in virus neutralizing antibody titre.

Serum immunoglobulin concentrations in febrile convulsions.

The mean, age adjusted, serum IgA values of 47 children with febrile convulsions were almost identical to those of controls. Five children had serum IgA values less than 0.1 g/l by nephelometry, suggesting that in some cases at least there may be an association between a low serum IgA concentration and febrile convulsions.

Serum immunoglobulin concentrations in preschool children measured by laser nephelometry: reference ranges for IgG, IgA, IgM.

Serum immunoglobulin concentrations were determined on sera from 298 healthy children aged six months to six years using the Hyland laser nephelometer PDQ system. Age-specific 95% reference ranges for serum IgG, IgA and IgM are presented; considerable care has been taken to ensure statistical validity of the reference ranges. The wide range of values in children under two years suggest that measuring immunoglobulin concentrations in this age group is of little value in diagnosing immunodeficiency.

Epidemiology of coronavirus respiratory infections.

Human coronaviruses were found by enzyme linked immunosorbent assay in upper respiratory tract secretions taken during 30% of 108 acute respiratory infections experienced by 30 children under age 6 years with recurrent respiratory infections (index group), and during 29% of 51 acute infections experienced by their siblings. Lower respiratory tract infection--predominantly wheezy bronchitis--occurred in 30% of the index children's coronavirus positive infections but in none of their siblings' infections. Reinfections were common.