In three pregnancies at risk for citrullinemia affected fetuses were predicted both by strongly increased levels of citrulline in the amniotic fluid and by the reduced incorporation of 14C-citrulline into TCA-precipitable material in cultured amniotic fluid cells. The prenatal diagnoses of affected fetuses were confirmed after termination of the pregnancies by direct and indirect assays of argininosuccinate synthetase in the fetal livers and fibroblasts respectively. Measurement of the citrulline concentration in amniotic fluid appears to be a valuable adjunct in the prenatal diagnosis of citrullinemia.

Amino Acid Metabolism, Inborn Errors↗

PubMedDate not supplied

The value and safety of percutaneous lung aspiration for children with serious pulmonary infections.

It is often difficult to establish the etiology of pulmonary infections in children. The diagnostic value and safety of percutaneous needle aspiration of the lung were investigated in 98 children who were suspected of having a bacterial pulmonary infection and who were seriously ill or had failed to respond to apparently adequate empiric antimicrobial therapy. The etiology of the pulmonary infection was established in 60 patients (61%); in the remaining 38 cases (39%) no bacterial microorganisms were recovered from the lung aspirate. Twenty-four (40%) patients in whom the pathogen(s) were identified were already receiving empiric antimicrobial therapy, and in 18 (66%) the original therapeutic regimen had to be changed to optimally treat the isolated microorganism(s). A total of 11 complications occurred in 10 children (10%): 9 pneumothoraces and two instances of mild, self-limited hemoptysis. Six of the pneumothoraces (66%) required treatment by either a thoracostomy and chest-tube or simple percutaneous aspiration. There were no deaths related to the procedures. It was concluded that percutaneous needle aspiration of the lung in children is a potentially useful and reasonably safe technique for the diagnosis of pulmonary infection in carefully selected cases when an exact etiologic diagnosis is needed.

Bacterial Infections↗

PubMedDate not supplied

A minority of 46,XX true hermaphrodites are positive for the Y-DNA sequence including SRY.

A total of 30 cases of 46,XX true hermaphroditism was analysed for Y-DNA sequences including the recently cloned gene for male testis-determination SRY. In 3 cases, a portion of the Y chromosome including SRY was present and, in 2 cases, was localised, to Xp22 by in situ hybridisation. Since previous studies have shown that the majority of XX males are generated by an X-Y chromosomal interchange, the Xp22 position of the Yp material suggests that certain cases of hermaphroditism can arise by the same meiotic event. The phenotype in the 3 SRY-positive cases may be caused by X-inactivation resulting in somatic mosaicism of testis-determining factor expression giving rise to both testicular and ovarian tissues. Autosomal or X-linked mutation(s) elsewhere in the sex-determining pathway may explain the phenotype observed in the remaining 27 SRY-negative cases.

Adolescent↗

PubMedDate not supplied

Relationship between age and heart rate variability in supine and standing postures: a study of spectral analysis of heart rate.

We compared heart rate variability measures of 11 normal children (4-12 years) to 23 normal adults (21-43 years) to study the effect of age on heart rate variability measures. Children had a significantly higher supine and standing heart rate and lower supine and standing systolic and diastolic blood pressure. Children also had a significantly higher supine standard deviation of HR, supine low frequency (0.01-0.05 Hz) (p < 0.005), supine high frequency (0.2-0.5 Hz) (p < 0.001), and standing high frequency powers (p < 0.005) compared to adults. The ratio of mid frequency (0.07-0.15 Hz) to high frequency power (0.2-0.5 Hz) upon standing was significantly lower in children (p < 0.005). While there was a significant increase of the mid frequency power from supine to standing posture in the adult group (p < 0.02), there was no such significant increase in children. There were also significant negative correlations between age and supine low frequency, mid frequency, and high frequency powers, and standing high frequency power. These findings illustrate a decrease of cholinergic and an increase of adrenergic modulation of heart rate variability with age (4-43 years).

Adrenergic Fibers↗