Maternal complications of normal deliveries: variation among rural hospitals.

This study examined variation in maternal complication rates following normal vaginal delivery among 282 rural hospitals throughout the United States. Using a risk-adjusted model to control for case mix, discharge abstracts of more than 84,000 women were analyzed to determine whether there were differences in outcomes resulting from, or concomitant with, their hospital stay. After risk adjustment, the majority of hospitals were found to be performing at an acceptable level; however, there were some factors associated with poor performance. Hospital volume and the availability of obstetricians in the county in which the hospital was located were found to have an inverse association with complication rates, whereas low county per capita income was found to have a positive association with poor facility performance. No association was found between complication rates and general practitioners and the degree of remoteness as defined by distance from the nearest tertiary care facility. The results demonstrate a relationship between volume and outcome and a threshold point at which volume becomes a significant factor in predicting facility performance. As well, a relationship is seen between physician specialty and outcome, in which obstetricians are significantly associated with facility performance at expected or better-than-expected levels. Normal vaginal delivery is an important service provided by rural hospitals. The relationships among volume, physician specialty and outcome suggested by these findings require further in-depth examination of specific factors that affect patient outcomes and overall facility performance.

Merosin-deficient congenital muscular dystrophy and cortical dysplasia.

Congenital muscular dystrophy (CMD) encompasses a heterogenous group of muscle disorders with autosomal recessive inheritance, characterized by muscular weakness and hypotonia at birth or within the first few months of life and developmental delay. Merosin-deficient CMD is a clinically distinct form which may be associated with significant abnormalities of the brain detectable by neuroimaging. We report two siblings of consanguineous parents with merosin-deficient CMD in an Irish family who in addition to the characteristic white matter abnormalities on neuroimaging, had occipital dysplasia. Clinical, electrophysiological muscle biopsy findings and neuroimaging were very similar in both cases. Although merosin-deficient CMD with white matter abnormalities on neuroimaging is well documented in the literature, the association with occipital dysplasia has only rarely been reported. The appearance of an identical cortical defect in these siblings suggests an underlying genetic mechanism.

Human immunoglobulin (IgG) induced deletion of IgM rheumatoid factor B cells in transgenic mice.

The singular ability of immunoglobulin genes to hypermutate their variable regions, while permitting the generation of high-affinity antibodies against foreign antigens, poses a problem in terms of maintenance of immunological self-tolerance. Immunoglobulin gene hypermutation driven by a foreign antigen has the potential to generate antibodies that cross-react with self-components. Consequently, there must exist a mechanism in the periphery for inactivation of mature autoreactive B cell clones. The classical experimental system used to address this problem is the induction of tolerance to soluble, deaggregated human IgG. We have analyzed the mechanism of induction of tolerance to human IgG using transgenic mice that express a human IgM rheumatoid factor (IgM RF) on a large proportion of their B cells. Injection of deaggregated human IgG caused a specific deletion of those B cells that express an intact IgM RF on their cell surface. The degree of RF B cell deletion was proportional to the reduction in the proliferative response of splenocytes to antigen (aggregated human IgG), or to F(ab')2 fragments of anti-human IgM antibodies. Control experiments showed that IgG administration had little effect on the numbers of mouse Ig-bearing cells or their ability to proliferate to a nonspecific mitogen. Thus, the effects of IgG on the human IgM RF B cell are antigen specific and are not due to nonspecific toxic effects of the human IgG preparation. These experiments demonstrate that peripheral exposure to IgG induces deletion of reactive B cells, without any evidence for anergy, and differ from data obtained by other investigators studying tolerance to soluble protein antigens. The results imply that human Igs have distinct properties as soluble antigens, and that peripheral nonresponsiveness to IgG may be due to lymphocyte deletion.