James L. Bennington

Plasmapheresis in childhood dermatomyositis.

DERMATOMYOSITIS is an inf lammatory disease of muscle present ing as a syndrome of proximal muscle weakness accompanied by an ery thematous skin rash. Classical his topathologic features on muscle biopsy, as given in order of f requency by Pearson, 1 are degenera t ion , regenerat ion and necrosis o f muscle fibers, in f l ammatory infiltration, var ia t ion in fiber size, and intersti t ial fibrosis. The under lying lesion in some chi ldhood cases, however, appears to be ischemia caused by a vasculopathy of small veins, arteries, and capillaries. ~-4 The finding by Whi t ake r and EngeP of vessel wall deposits of IgM together with a variable deposi t ion of IgG and C3 in n ine of 11 muscle biopsies f rom cases of ch i ldhood dermatomyosi t i s suggests that the vascular lesions migh t be caused by the deposi t ion o f autoant ibodies or i m m u n e complexes, and therefore would be amenable to p lasmapheres is therapy.

Pulmonary embolism in an infant.

A case of fatal pulmonary embolism in a 13-month-old infant is reported. Severe dehydration associated with diarrhea had been treated with intravenous fluids through an indwelling polyethylene catheter placed in the right greater saphenous vein. The embolus is believed to have arisen at the site of the resultant thrombophlebitis of this vessel. The rarity of pulmonary embolism in infancy is stressed and a summary of its incidence in 10,000 autopsies from the Department of Pathology of the University of Chicago is presented and compared with other reported series.

The embryologic significance of an undifferentiated intestinal tract

A newborn infant who died with evidence of profound gastrointestinal dysfunction was found at autopsy to have malrotation of a short, incompletely differentiated intestine, with absence of appendix and cecum. Three other cases of incomplete differentiation of the intestine were found in the literature. One was in a sirenomelus; in two adults the abnormality was an essentially incidental finding. The absence in the embryo of a more dilated colon and cecum at the time of the return of the caudal limb of the midgut from its extracelomic position is thought to account for the associated malrotation.

Radioautographic analysis of soluble antigen-antibody complexes separable by paper electrophoresis.

Summary A radioautographic technic with a sensitivity many times greater than conventional staining methods is described for evaluation of paper electrophoretic studies of soluble antigen-antibody complexes. Electrophoretic mobilities of BSA-anti BSA soluble complexes relative to rabbit serum proteins are reported with a semi-quantitative analysis of percentage concentration for each of the complexes at various values of antigen excess.