B Nabarra

The serum thymic factor (FTS) utilized in its synthetic or natural form loses its biological activity in a rosette assay after treatment with a metal ion-chelating agent, Chelex 100. This activity is restored by the addition of Zn salts and, to a lesser extent, certain other metal salts. FTS activation is secondary to the binding of the metal to the peptide. The metal-to-peptide molar ratio of 1:1 provides the best activation. These data indicate the existence of two forms of FTS. The first one lacks Zn and is biologically inactive; the second one contains Zn and is biologically active, for which we propose the name of "thymulin" (FTS-Zn). The presence of Zn in synthetic FTS was confirmed by atomic absorption spectrometry. The interaction between Zn and FTS was further suggested by microanalysis demonstrating the presence of this metal in thymic reticuloepithelial cells.

Deposits with IgA as the main component frequently are found in the glomeruli of patients with cirrhosis of the liver. These deposits usually are latent. In some cases, however, they may be associated with proliferative changes and clinical manifestations of glomerular involvement.

Twenty-six children aged from 1 day to 15 years (18 boys and 8 girls) with visceral neuropathies are analyzed. Clinical symptomatology is dominated by abdominal distension, attacks of occlusion, abdominal pain, and malnutrition. Intestine bacterial overgrowth is frequent. From aspiration biopsies, surgical rectal biopsies, and, in some cases, ileal or ileocolic biopsies, histopathological studies revealed two patterns. One group had abnormalities of the myenteric plexus identified by conventional light microscopic studies, with two patterns: [myenteric plexus hyperplasia (9 patients), characterized by large ganglionic nodes, penetration into the mucosal zone, and altered argyrophilic neurons]. Clinically this pattern was observed in four patients with multiple endocrine neoplasia syndrome with risk of medullary thyroid carcinoma. The second pattern observed was characterized by glial cell hyperplasia (15 patients). Ganglion cells are present but are small and sparse, often infiltrated by collagen tissue; Schwann nerve fibers are hypertrophic. Eleven patients presented with neonatal intestinal obstruction. The second group is characterized by normal conventional light microscopic examination, but silver stains revealed important abnormalities of argyrophobic cells (one case) or argyrophilic cells (one case). In the two groups, most of the patients needed intestinal derivation and prolonged nutritional support with total parenteral nutrition.