purpose: to evaluate the corneal endothelial cell density and polymegathism one year after laser assisted keratomileusis using mitomycin c. methods: one hundred and three eyes from 52 patients who underwent laser assisted sub-epithelial keratomileusis using mitomycin c 0.02% for 30 seconds entered this study. corneal endothelial cells were evaluated using specular microscopy before and one year...

The length of double-stranded coliphage lambda DNA, as determined by electron microscopy using the benzyldimethylalkyl ammonium chloride technique, depends on the mode of dehydration. The freeze-dried DNA form is the longest (16.5 micron), whereas dehydration in methanol (15.9 micron) or in ethanol (three forms: 15.2 micron, 13.9 micron, and 12.4 micron) results in progressively shorter molecul...

Fenestrated capillaries are provided with two types of regular discontinuities: fenestrae with negatively charged diaphragms, and transendothelial channels fitted with two diaphragms, of which the luminal one is uncharged. These structures are expected to affect macromolecular exchanges on the basis of size and charge. We have detected variations in the surface density of fenestrations and tran...

Of 35 tuco-tucos (Ctenomys opimus) collected in Bolivia, South America, 31 (88%) had eimerian oocysts in their feces at the time they were examined. Eighteen (58%) of the 31 infected animals were concurrently infected with 2 or 3 eimerian species. Four species of Eimeria were recovered and are described as new species based on the characteristics of sporulated oocysts. Oocysts of Eimeria granif...