Cor pulmonale as a complication of methylmalonic acidemia and homocystinuria (Cbl-C type).

We report an infant with a bronchiolitis-like illness and rapid deterioration who developed a cor pulmonale-like picture with a dilated right ventricle. Urinary organic acid assays established a probable diagnosis of Cbl-C-type methylmalonic aciduria, later confirmed by complementation studies. Despite medical intervention and cyanocobalamin treatment the patient died on his tenth hospital day. Postmortem examination showed the presence of thromboemboli in the pulmonary circulation. We hypothesize that acute cor pulmonale developed in this infant secondary to thromboembolism of his pulmonary circulation. A review of the literature shows that thromboembolism may be a part of this disease process.

The effects of estrus cycle on drug metabolism in the rat.

The effect of the female rat estral cycle on microsomal drug metabolism in-vivo and in-vitro has been studied. Two microsomal enzymes, aminopyrine-N-demethylase and aniline hydroxylase showed a greater specific activity (p less than 0.01) in the diestrus phase of the estral cycle while the oxidative enzyme aryl hydrocarbon hydroxylase and the conjugative enzyme, glucuronyl transferase, were not affected. In vivo studies which included theophylline and antipyrine metabolism, and hexobarbital sleeping times showed no difference between the different phases of the estral cycle. Conflicting evidence about the effect of steroid sex hormones on hepatic drug metabolism is discussed.

Haemophilus influenzae B meningitis in a patient with a ventriculoperitoneal shunt and meningomyelocele.

A child with an implanted ventriculoperitoneal (VP) shunt and meningomyelocele had an infection of his cerebrospinal fluid (CSF). The organism cultured from the VP shunt apparatus and the meningomyelocele repair site was Haemophilus influenzae B (HIB), a very unusual pathogen in this setting. The patient was treated with the appropriate antibiotics, administered intravenously in accordance with accepted practice and available literature, with no improvement. The site of the persistent infection was finally determined to be within the meningomyelocele repair tissue. The patient's clinical status improved dramatically following the removal and replacement of the total shunt apparatus. The three-part apparatus tip was cultured according to the standard laboratory practice, but did not yield any organism. We conclude that the management of HIB meningitis in the presence of a VP shunt should include prompt removal of the apparatus. Recovery of the organism may be enhanced by separating the apparatus components and culture of the connections, instead of merely the indwelling tip.

Theophylline pharmacokinetics in pregnant and lactating rats.

As a preliminary investigation to a human study, we examined the pharmacokinetics of theophylline in pregnant and lactating rats. Three groups of female rats--pregnant, lactating, and virgin controls were injected IP with theophylline solution. Pregnant rats eliminated theophylline at a slower rate than both lactating rats and virgin controls, resulting in a longer half life (t1/2) and lower clearance. The approximate volume of distribution (aVd) and extrapolated peak concentration (Cp0) in the 3 groups were not different.

Sequential respiratory syncytial virus and cytomegalovirus pneumonia following bone marrow transplantation.

A 6-month-old child with familial hemophagocytic lymphohistiocytosis (FHL) experienced early sequential pneumonia due to respiratory syncytial virus (RSV) and cytomegalovirus (CMV) following bone marrow transplantation (BMT). The patient was deficient in natural killer (NK) cell activity (as found frequently in patients with FHL), and this risk factor may have played a major role in the concomitant infection by the two viral pathogens. Rapid diagnostic methods for both viruses are essential and early specific treatment may serve to ameliorate RSV- and CMV-induced lung injury in these life-threatening infections.