A strategy to enhance the usability of the minimal model as used with the intravenous glucose tolerance test in diabetes research and clinical management.

The Minimal Model method of determining Insulin Sensitivity from the Intravenous glucose Tolerance Test is a valuable tool for the Diabetes research community. However the Minimal Model algorithm itself is not readily available in a user-friendly modem windows environment to the clinical researcher in many research departments. In addition use of the model often requires intervention by an experienced "modeller" to interpret the results produced by the method.

Selective photoreceptor cell loss in hypoxic ischemia.

We studied the histopathologic changes in the brain and eye of a 5 1/2-month-old infant who suffered a profound hypotensive episode three days antemortem. Nuclear pyknosis and other histologic changes characteristic of ischemic cell necrosis were found throughout the brain and in the retina's photoreceptor-cell layer. These findings suggest that hypoxic ischemia may produce preferential damage to the photoreceptor-cell layer.

Orbital emphysema causing vision loss after a dental extraction.

The use of high-speed air-cooled rotary cutting instruments is common in dental practices. When used near open wounds, the forced air can lead to subcutaneous emphysema and involvement of vital structures. This case highlights the unfortunate episode of orbital emphysema with optic nerve damage after a pneumatically cooled drill was used in the removal of a mandibular second molar.

Chiasmal syndrome caused by pituitary-sellar disproportion.

A patient with pituitary-sellar disproportion, a perichiasmal visual field defect, and no clinically demonstrable endocrinopathy is presented. Radiographic and pathologic studies suggested that the pituitary-sellar disproportion was secondary to sellar hypoplasia, a previously unrecognized cause of the chiasmal syndrome. It remains to be seen whether hormonal manipulation aimed at suppression of gonadotropin- and/or prolactin-secreting cells might obviate the need for exploration in patients similar to ours.

Magnetic resonance imaging of optic gliomas.

We compared magnetic resonance imaging of the optic nerves and chiasm with computed tomography in four patients (a 17-year-old girl, a 14-year-old boy, a 13-year-old girl, and a 22-year-old woman) with biopsy-proven or suspected optic gliomas. Orbital abnormalities were effectively viewed by both techniques. Gliomatous and normal optic nerves had similar spin-echo magnetic resonance imaging characteristics.