Nabil M. Jabbour

Retinopathy of prematurity. The association of a persistent hyaloid artery.

In a review of 160 cases of retinopathy of prematurity (ROP), 14 patients were found to have an associated persistent hyaloid vascular system. The following four different manifestations of a persistent hyaloid system were identified: hyaloid artery anastomosed to peripheral neovascularization (1 case); hyaloid artery present with attached retina (3 cases); fibrous-appearing stalk with detached retina (3 cases); and massive persistent hyaloid vascular system (7 cases). In some cases, the hyaloid artery was only an associated finding and unrelated to ROP. In other cases, the hyaloid artery appeared to be an integral component of the retrolental membrane. Recognition of a massive persistent hyaloid artery has important prognostic value because the vessels are adherent to the retina and the retrolental membrane complicating surgical repair. The role of the associated hyaloid artery in ROP is described.

Oxidative/nitrosative stresses trigger type I diabetes: preventable in streptozotocin rats and detectable in human disease

Recently we demonstrated that streptozotocin (STZ) diabetes (type I) in rats is preventable using a simultaneous equimolar injection of carboxy‐PTIO (c‐PTIO). Both changes in blood sugar and cataracts are prevented. This apparently occurs because the nitric oxide (NO) (from STZ) generated in the beta cells is oxidized to nitrite by c‐PTIO preventing diabetes. STZ generates NO producing a NO‐based toxin. The toxin damages DNA by nicking and activates poly‐ADP‐ribose causing necrosis and triggering inflammation. Is there evidence that O/N stress occurs in early human type I diabetes? We studied 40 children with or without early type I diabetes and observed that urate is decreased 25% in all these diabetic children each over the age of 3 years. Urate is a major portion of blood‐antioxidant load. Surely this decrease in urate indicates ongoing O/N stress. Does O/N stress initiate disease? STZ studies in rats indicates that this is correct.