Faculty Bibliography

PURPOSE: Yersinia enterocolitica sepsis is rarely encountered in patients without an underlying susceptibility and is most frequently reported in iron-overloaded patients. This is thought to be related to the unusual utilization of iron by this microorganism. We report a case of Y. enterocolitica bacteremia in a chronically transfused adolescent with sickle cell anemia. This type of serious infection in sickle cell disease is previously unreported. A description of the case and the relationship between Y. enterocolitica and iron is discussed. A review of the literature is presented. RESULTS: Y. enterocolitica can cause a severe septicemia, and increased virulence of this organism has been shown to correlate with increased iron burden and/or use of the chelator deferoxamine. It may also occur as a consequence of a contaminated blood transfusion. CONCLUSIONS: We believe our case demonstrates that Y. enterocolitica should be considered a possible pathogen in febrile chronically transfused patients with sickle cell disease. Broad antibiotic coverage should be initiated and deferoxamine discontinued pending results of cultures

Recently, a novel class of angiostatic steroids which block angiogenesis in several systems has been described. Since the elaboration of proteases is believed to be an important component of angiogenesis, we tested whether these steroids blocked the fibrinolytic response of endothelial cells to the angiogenic protein, basic fibroblast growth factor [bFGF]). Cultured bovine aortic endothelial (BAE) cells were incubated with bFGF and/or medroxyprogesterone acetate (MPA), an angiostatic steroid which has been shown to inhibit vascularization, collagenolysis, and tumor growth. When bFGF (3 ng/ml) was added to confluent monolayers of BAE cells, plasminogen activator (PA) activity in the medium was increased threefold. In contrast, MPA at 10(-6) M, 10(-7) M, 10(-8) M, and 10(-9) M decreased PA levels in the medium by 83%, 83%, 75%, and 39%, respectively. The stimulation of PA levels in BAE cells by bFGF (3 ng/ml) was abrogated by the presence of 10(-6) M MPA. This decrease in PA activity was found to be mediated by a significant increase in plasminogen activator inhibitor type-1 (PAI-1) production. MPA, therefore, negated one of the important enzymatic activities associated with the angiogenic process. In contrast to the decreased levels of secreted PA in cultures exposed simultaneously to MPA and bFGF, cell-associated PA levels remained high, consistent with earlier observations indicating that PAI-1 does not inhibit cell-associated PA. Thus, angiostatic steroids may exert their inhibitory effects on angiogenesis by increasing the synthesis of PAI-1. This, in turn, inhibits PA activity and, therefore, plasmin generation, which is essential for the invasive aspect of angiogenesis

We cared for an infant girl with the clinical constellation of supraumbilical midabdominal raphe, sternal atresia, and cutaneous facial and upper trunk hemangioma. This is the first report of this clinical association in the dermatologic literature. The vascular component of the disorder responded to flashlamp-pumped pulsed dye laser therapy and to systemic interferon alfa-2a (Roferon-A)

Plasma prothrombin levels in newborn humans are lower than in adults. The same is true of many newborn and fetal mammals, including the rabbit. To determine if the lower levels are due to less expression of the protein, we have compared mRNA for prothrombin in fetal and adult rabbit liver. Northern blots were hybridized with a cDNA for rabbit prothrombin revealing a single mRNA of approximately 2 kb in both adult and fetal animals. mRNA specific for prothrombin was quantitated by slot blotting of RNA prepared from adults and fetuses aged 21 d to term (31 d). Prothrombin-specific mRNA in fetuses was greater than 50% of that in adults even when the fetal plasma prothrombin was only 15% of the adult level. This suggests that low plasma levels in the fetuses are not the result of less transcription. Examination of liver sections revealed that the predominant tissue in the fetus is hematopoietic, not hepatic. In the youngest fetuses, less than 20% of the liver consisted of hepatocytes, yet these fetuses expressed more than 50% of the adult level of prothrombin-specific mRNA. Thus, transcription of prothrombin mRNA may be proceeding at a greater rate in the fetal hepatocyte than in the adult, or hematopoietic cells may be expressing the protein. We conclude that in fetal rabbit liver, prothrombin is expressed at a high level relative to the hepatocyte content and that the cause of the low plasma levels is posttranscriptional