Fulminate retinopathy of prematurity - clinical characteristics and laser outcome.

PURPOSE: To analyse the clinical characteristics and treatment outcome of zone 1 Fulminate type of Retinopathy of Prematurity (ROP) and compare it to Conventional ROP. METHODS: Preterm infants from two neonatal intensive care units (NICU) born between July 2002 and November 2003 were screened for ROP. Cases with Conventional ROP were classified according to the International Classification of Retinopathy of Prematurity (ICROP) while that of Fulminate ROP according to Shapiro's classification. Threshold disease was kept the cut off for treatment for Conventional ROP and stage 3A for Fulminate ROP. RESULTS: Of the 54 cases that had treatable ROP, 36 (66.67%) had Fulminate type. The mean gestational age and birth weight was higher in Fulminate ROP compared to Conventional disease (31.75 weeks and 1554 gms vs 31 weeks 1387 gms) whereas the mean postnatal age at laser was lower (4.62 weeks vs 6.3 weeks). The average number of laser spots given was 3036.6 for Fulminate disease. CONCLUSION: Fulminate ROP had an atypical morphology which was difficult to classify according to ICROP classification and we would like to lay stress upon the importance of screening of premature infants from the age of 4 weeks and to start treatment immediately once Fulminate ROP has been diagnosed.

Investigation of Thin Aqueous Films on Silica Using a Modified Interferometric Technique.

The thinning behavior of liquid films between free bubbles and silica is investigated using the interferometric technique. Stable films were obtained at higher salt concentrations compared to previous studies because of the improved cleaning procedure. In contrast to the captive bubble technique used in the past, the free bubble method employed more closely approximates such processes as flotation. The results obtained for aqueous films at low and high ionic strengths are in better agreement with theoretical predictions than those in previous studies. Copyright 2000 Academic Press.

Catalytic properties of a calmodulin-regulated transglutaminase from human platelet and chicken gizzard.

The kinetic parameters and some enzymatic characteristics of human platelet and chicken gizzard transglutaminases were determined. Activity of the transglutaminases was regulated by calmodulin. These enzymes co-isolated with alpha-actinin and were dissociated from alpha-actinin by gel filtration and absorption onto a calmodulin affinity column. Silver-stained polyacrylamide gels showed that the protein peak eluted by EGTA from this column contained polypeptides of Mr approximately 58,000 and 63,000. The transglutaminases required Ca2+ for incorporation of monodansylcadaverine into casein and actin substrates. Activity was enhanced 3-fold by calmodulin with a biphasic effect, showing stimulation at 10-200 nM and inhibition at concentrations higher than 300 nM. In the presence of 200 nM calmodulin, half-maximal transglutaminase stimulation was obtained with 2.5 microM free [Ca2+]. Chlorpromazine inhibited calmodulin enhancement of the transglutaminases. Activity of the transglutaminases was independent of proteolytic activation, since inhibitors for Ca2+-dependent proteases failed to inhibit filamin cross-linking. For comparison, factor XIIa, a plasma and platelet transglutaminase, required both Ca2+ and thrombin for activation and was insensitive to calmodulin. The cross-linking pattern of fibrin, fibrin monomers, and fibrinogen by the calmodulin-regulated transglutaminases showed, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, disappearance of fibrinogen alpha-chains with no decrease of beta- and gamma-chains or formation of gamma-gamma dimers. By autoradiography, cross-linked products of 125I-fibrinogen revealed heavily labeled high molecular weight polymers and polypeptides of Mr 98,000, 116,000, and 148,000; the latter appeared to be a transient species. However, when fibrin, fibrin monomers, and fibrinogen were used as factor XIIIa substrates, gamma-gamma dimers and alpha-polymers were formed. Formation of gamma-gamma dimers was slower with fibrinogen than with fibrin. Iodoacetamide blocked activity of factor XIIIa but not of the calmodulin-regulated transglutaminases.