Age-related RGC loss of up to 50% can occur in the C57 mouse by 18 months of age. The loss does not proceed linearly with age, as is often assumed, and differs both in extent and locational pattern from pathologic RGC loss secondary to glaucoma in DBA/2NNia mouse retinas.

Episcleral vein cauterization (EVC) is used in rats to generate a glaucoma model with high intraocular pressure (IOP). The long-term retinal damage in this glaucoma model however, has not been accurately quantified. We report the location and amount of retinal ganglion cell (RGC) damage caused by (EVC) induced IOP elevation in two rat strains.IOP was raised in one eye of Wistar(N=5) and Brown-Norway(B-N)(N=7) rats by EVC and monitored monthly until IOP in contralateral eyes equalized at 5 months post-surgery. Animals were maintained for 3.5-4.5 additional months. B-N rats(N=7) that had no EVC served as controls for this strain. Scotopic flash ERGs were recorded at baseline and just prior to euthanasia. Automated counts of all retrogradely labeled RGCs in retinal flat-mounts were determined and compared between contralateral eyes. RGC density maps were constructed and RGC size distribution was determined.Oscillatory potentials in the group of eyes which had elevated IOP were decreased at the time of euthanasia, when IOP had returned to normal. A group of normal B-N rats had similar RGC counts between contralateral eyes. In the experimental group the mean number of RGCs was not significantly different between control and experimental eyes, but 1 of 5 Wistar and 2 of 7 B-N experimental eyes had at least 30% fewer RGCs from contralateral control eyes. Total retinal area in B-N experimental eyes was higher compared with contralateral eyes. Cumulative IOP exposure of the experimental eyes was modestly correlated with RGC loss while oscillatory potentials appeared to be inversely related to RGC loss. In retinas with extensive (>30% RGC loss) but not complete damage, smaller cells were preserved better than larger ones.The above results indicate that RGC loss in both Wistar and B-N strains is variable after a prolonged elevation of IOP via EVC. Such variability despite equivalent IOP levels and ERG abnormalities, suggests unknown factors that can protect IOP-stressed RGCs. Identification and enhancement of such factors could prove useful for glaucoma therapy.

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Resumen El leiomiosarcoma digestivo es una neoplasia poco común, siendo el lugar de asentamiento más frecuente el estómago, seguido del intestino delgado (íleon). Sólo el 3% de los casos afectan al colon. En este último caso habría que hacer un diagnóstico diferencial fundamentalmente con el adenocarcinoma de colon. Su diagnóstico es histológico con necesidad de inmunohistoquímica, y su tratamiento curativo consiste en la cirugía, habiendo demostrado la quimio y radioterapiapocobeneficio.Supronósticoespobre,yaquelarecidivatras la cirugía y la diseminación hematógena son frecuentes.

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