Response and decline of serum IgG antibodies to pertussis toxin, filamentous hemagglutinin and pertactin in children with pertussis.

The serum IgG antibody response and decrease to 3 Bordetella pertussis antigens was compared in children with pertussis. Sera were obtained at the first clinical visit and 1, 3 and 12 months later from 89 children with > or = 3 weeks of paroxysmal cough. IgG antibodies to pertussis toxin (PT), to filamentous hemagglutinin (FHA) and to pertactin were determined with ELISA. Of 54 children with culture-confirmed pertussis or culture-confirmed familial exposure, 45 (83%) had a significant (> or = 3 fold) increase in PT IgG and 40 (74%) in FHA IgG antibodies, while only 29 (54%) had a significant increase in pertactin IgG antibodies. Significant decreases in PT, FHA and pertactin IgG antibodies were found in 34 (63%), 9 (17%) and 28 (52%) children, respectively. In the remaining 35 who did not have culture-confirmed disease, significant PT and/or FHA IgG antibody increases (criteria for pertussis according to the WHO definition) were found in 17 (49%). Only 6 of these 17 children had a significant pertactin IgG antibody increase. Of the remaining 18 children (who did not fulfil WHO criteria for pertussis), significant decreases in PT and/or FHA IgG antibodies were found in 13. We conclude that a serum IgG reaction to PT and FHA occurs in almost all children with pertussis. An increase in pertactin IgG antibodies occurs less frequently than against PT and FHA. Significant decreases in PT or FHA IgG antibodies in children with clinical pertussis might be of use as a diagnostic criterion in children brought late for examination.

Changing cognitive outcome in preterm infants with hyaline membrane disease.

One hundred seventy-four preterm survivors of hyaline membrane disease, born 1961 through 1971, were followed up for at least six years with serial psychological and neurological evaluations. This relatively mature population had a mean birth weight of 2,133 g and gestational age of 34.6 weeks. All children had consecutive preschool and school age psychological tests. The mean preschool test score was 91 (SD = 13) and the mean school age score was 101 (SD = 16). The ten-point difference between the mean preschool and school age test scores was significant. Perinatal variables and indexes of disease severity did not correlate with test scores. Higher test scores were correlated with higher paternal educational and employment levels. Improving test scores by school age may be due to test instruments that measure different cognitive skills and/or the diminishing effects of prematurity.

Pulmonary vascular resistance in ventricular septal defects. The long-term prognosis as evaluated by the thermodilution method.

Twenty-six children with ventricular septal defects were investigated using the thermodilution method for determining pulmonary blood flow and calculating pulmonary vascular resistance (PVR). Fourteen were followed sequentially. All were below 2 years of age at the first investigation. Eleven of them had a PVR of three units or more. Six of the children in this group died; four at operation, two before operation. One has a residual shunt and equilibrated pressures. Fifteen patients had a PVR below three units; two of them died, none had any long-term complications. In the high-resistance group, sequential determinations of PVR with the thermodilution method further helped to separate those with a poor prognosis from those whose pulmonary vascular bed was still reactive and for whom prognosis was good.

Systolic time intervals in children with heart disease.

Of the systolic time intervals, the preejection period is known to correlate well with invasively measured isometric contraction time, and increase of the quotient preejection period/left ventricular ejection time (PEP/LVET) is considered to be of a good indicator of left ventricular failure. The different systolic time intervals have been recorded from the carotid pulse curve from 40 normal children, 20 aged five and 20 aged ten years. Their PEP/LVET was 0.31 +/- 0.04. Seventy-eight children with different heart diseases were then investigated. In patients with congenital total heart block or extrasystoles, there was a negative correlation between PEP/LVET and the R-R interval, in accordance with the Frank-Starling law. In patients with ventricular septal defects PEP/LVET differentiates between small and large shunts; the increased PEP/LVET of the latter normalizes after operation. The increased PEP/RVET of children with transposition of the great arteries is an expression of the inadequacy of the right ventricle as a systemic chamber. In aortic stenosis "normalization" of a previously decreased PEP/LVET may indicate early left ventricular failure. In primary myocardial disease registration of the systolic time intervals enables us to follow the left ventricular function more closely than is possible with invasive techniques.

Role of hyaline membrane disease in production of later childhood lung abnormalities.

Between 1961 and 1970, 177 survivors of hyaline membrane disease have been followed clinically and roentgenologically for a minimum of three years to determine the long-term pulmonary outcome. Of these, 153 have been seen for at least six years and 61, for 11 years or more. A total of 175 batteries of pulmonary function tests have been performed on 129 children at age 7 and/or 11 years, Final roentgenograms showed fibrosis in 12 instances, and these changes were positively correlated with the severity of the initial disease, the use of a positive pressure respirator (but not negative pressure respirator), time on the respirator, and length of time in O2, but not high O2 concentrations. Residual symptoms in the first years of life were also correlated with positive pressure respirator use, length of use, and with secondary infection. Pulmonary function tests showed minimal abnormalities in 12 children when last seen. None of these children had a history of exercise intolerance or chronic respiratory symptoms. The ultimate pulmonary history of this population of patients is unknown, but overt childhood lung disease following hyaline membrane disease is not a frequent occurrence.

The applicability of the thermodilution method for determination of pulmonary blood flow and pulmonary vascular resistance in infants and children with ventricular septal defects.

The thermodilution method is accepted for measuring cardiac output in adults without shunts. It has been shown to work in animals the same size as newborn infants and has recently been used in children with congenital heart defects. We have proved its clinical applicability in determining the pulmonary blood flow, in twenty-five infants and children with VSD. The pulmonary vascular resistance can be calculated more accurately than by the Fick principle with an assumed O2 consumption, which has often had to be done in earlier studies.

Systolic time intervals in newborn infants.

Systolic time intervals, calculated from the carotid artery pulse curve have been used for some time to assess left ventricular performance. Normal values have been established for adults and older children, but few investigations have been made on newborn infants, generally with partly contradictory results. Therefore a study has been undertaken in 29 normal newborn infants 1/2-119 hours old, and 9 infants 2-3 months old to establish normal values for different intervals. They were found to differ from those reported for adults and older children, most clearly seen in the relatively long preejection period (PEP). Statistically significant differences were found between the PEP of 20 infants below 47 hours of age and 9 infnats 2-3 months old: PEP 82 ms and 68 ms respectively. (p less than 0.01); the same is true of the quotient PEP/LVET (left ventricular ejection time), which was found to be 0.41 and 0.35 resp. (p less than 0.01). By adult standards this would mean impairment of left ventricular function. A possible explanation of this could be a difficulty for the left ventricle to cope with the systemic circulation during the first days of life even in normal newborns, a difficulty not fully compensated for even at 3 months of age.