Population-based study of congenital heart defects in Down syndrome.

Mental retardation and hypotonia are found in virtually all Down syndrome (DS) individuals, whereas congenital heart defects (CHDs) are only present in a subset of cases. Although there have been numerous reports of the frequency of CHDs in DS, few of the studies have had complete ascertainment of DS in a defined geographic area. The Atlanta Down Syndrome Project, a population-based study of infants born with trisomy 21, provides such a resource. In the first 6.5 years of the study, 243 trisomy 21 livebirths were identified in the five-county Atlanta area (birth prevalence: 9.6/10,000). Cardiac diagnoses were available on 227 (93%) of the cases and 89% of these evaluations were made by echocardiography, cardiac catheterization, surgery, or autopsy. Of the 227 DS infants, 44% had CHDs including 45% atrioventricular septal defect (with or without other CHDs), 35% ventricular septal defect (with or without other CHDs), 8% isolated secundum atrial septal defect, 7%, isolated persistent patent ductus arteriosus, 4% isolated tetralogy of Fallot, and 1% other. This report is unique in that it contains the largest number of trisomy 21 infants ascertained in a population-based study where modern techniques for diagnosing cardiac abnormalities predominate.

Cardiac recovery and survival after neonatal myocardial infarction.

Management of cardiogenic shock following neonatal myocardial infarction (MI) has received little attention in the literature. Advances in medical support have been pharmacologic in nature, yet the outcome remains dismal. We report the course of a neonate after MI. Extracorporeal membrane oxygenation was utilized for hemodynamic support during the immediate post-MI period. The patient initially was in massive cardiogenic shock, but her myocardial function recovered completely. She has a normal neurodevelopmental outcome at 22 months of age.

Determination of molecular forms of brain acetylcholinesterase: technical considerations.

Sucrose density centrifugation has been used to characterize the relative levels of AChE molecular forms in different parts of the brain, during development, or in various disease states. We have examined the influence of various tissue or sample storage and handling techniques on the abundance of the 4S and 10S molecular forms of AChE in rat forebrain. Our results demonstrate that freezing either a subcellular fraction or the intact tissue causes dramatic shifts in the level of the 4S and 10S molecular forms as compared to the values obtained in fresh tissue. Total AChE activity was unchanged suggesting that 4S and 10S forms are equally active and that 4S AChE is easily dissociated from 10S. These observations suggest that 4S and 10S molecular forms in brain are extremely labile and that great care should be taken when studying the factors that regulate these forms.