Sequential renal alterations in septic shock in the primate.

This is a descriptive sequential study of the response of the baboon to LD100 Escherichia coli. The response was found to consist of three stages based on electron microscopic, physiologic, and clinical laboratory data. This study associates the inflammatory, coagulant, and cell injury (stage 1-3) responses with markers of activation of inflammatory cells (tumor necrosis factor) and of the vascular endothelium (tissue plasminogen activator). This work also shows that in contrast to the underlying parenchymal cells of the organ, the vascular endothelium remains intact throughout the response to LD100 E. coli. The possible role of the vascular endothelium in mediation of events at both its luminal (blood) and antiluminal (parenchymal) surfaces is discussed.

Cyclosporine suppression of endothelial prostacyclin generation. A possible mechanism for nephrotoxicity.

The effects of cyclosporine (CsA) on prostacyclin (PGI2) release by cultured human umbilical vein endothelial cells were investigated. PGI2 production was measured by radioimmunoassay of its stable metabolite 6-Keto-PGF1 alpha. CsA induced a time and concentration-dependent reduction in unstimulated (basal) and Ca++ ionophore (A23187)-stimulated release of PGI2. A 16-hr incubation with CsA reduced A23187 PGI2 release by 64% (P less than 0.05); CsA at concentrations of 1.0, 10.0, and 100.0 micrograms/ml reduced A23187 PGI2 release by 67%, 80%, and 90%, respectively (P less than 0.05). This suppression was reversed within 24 hr after withdrawal of CsA. Arachidonic acid-stimulated PGI2 release was also decreased in CsA-treated cells, indicating an inhibitory effect distal to phospholipase A2. 3H-deoxyglucose release, an indicator of cell injury, was not increased by CsA, thus excluding nonspecific cell damage as a mechanism of the observed suppressive effect. This inhibition of PGI2 release from endothelial cells by CsA may explain the increased renal vascular resistance and renal microvascular thrombosis seen on occasion with CsA administration.

Peripheral neuroepithelioma in childhood.

Peripheral neuroepithelioma is a rare and controversial neoplasm that may occur at any age. Fifteen of the 38 previously reported cases have involved children from birth to 17 years of age. The authors observed the course of a 3-month-old girl who presented with an enlarging mass in the left arm and manifested hepatic metastases at the time of diagnosis. The urinary level of vanillylmandelic acid (VMA) was moderately elevated. The primary lesion was excised and metastatic foci showed response to a regimen of vincristine, cyclophosphamide, Adriamycin (doxorubicin), and cisplatin. However, tumor recurred in the brain and liver and the child died 14 months after diagnosis. At autopsy, there was no involvement of adrenal glands or sympathetic ganglia and the liver contained numerous involuted lesions as well as active metastases. It is suggested that this is a unique neoplasm, derived from neural crest but distinct from neuroblastoma, which can be characterized by peripheral origin, a histologic pattern of confluent pseudorosettes, and aggressive clinical behavior.