PubMed Health⌕ Search

Biomedical subjects

P Dugal

Publications and source records attributed to P Dugal.

4 recordsLinked to original sources

Pentoxifylline suppression of TNF-alpha mediated axonal degeneration in the rabbit optic nerve.

In AIDS patients, axonal degeneration in the optic nerve occurs as a histopathological manifestation of the optic neuropathy. Direct infection of neurons by HIV is unlikely, and the axonal injury may be an indirect effect mediated by cytotoxic factors such as tumor necrosis factor-alpha (TNF-alpha) which we have previously demonstrated to cause axonal degeneration in the rabbit optic nerve. To test the suppressive effects of pentoxifylline in preventing TNF-alpha-mediated axonal degeneration, we applied pentoxifylline to an established rabbit model that demonstrates an AIDS-like optic neuropathy using intravitreal TNF-alpha injections. Degenerated axonal profiles were numerous in control rabbit optic nerve (mean 1879) and reduced in rabbits receiving the medium dose of pentoxifylline (300 mg PO BID, mean 439, p < 0.001) and the highest dose of pentoxifylline (600 mg PO BID, mean 120, p < 0.007). High dose pentoxifylline reduced TNF-alpha-induced axonal losses to less than 10% that seen without pentoxifylline pretreatment. Lower doses of pentoxifylline had a lesser but significant protective effect. Our results suggest that TNF-alpha-mediated axonal degeneration can be suppressed by high doses of pentoxifylline. Pentoxifylline may therefore be useful in AIDS patients demonstrating neurological or neuro-ophthalmological symptoms.

Animals↗

A test for patency of the cystic duct in acute cholecystitis.

A procedure was devised to quickly and reliably determine the patency of the cystic duct in patients suspected of having acute cholecystitis. First the gallbladder was stimulated to empty by a cholecystokinin injection. Thirty minutes later a radiolabeled biliary marker, either 150 muCi 131-I rose bengal or 2 mCi 99-mTc dihydrothioctic acid, was injected, and the accumulation of radioactivity in the liver and gallbladder regions was monitored by external gamma emission imaging and recording devices. The images of diagnostic importance were obtained between 60 and 90 minutes after injection of the tracer. Thirty-nine patients with acute abdominal pain were studied. Ten patients who had acute cholecystitis failed to show gallbladder accumulation of radioactivity, reflecting the cystic duct obstruction that initiates this disease. Twenty-nine patients having a variety of other diseases all showed gallbladder accumulation of activity, indicating in each patient that the cystic duct was patent. No significant adverse effects were noted. We conclude that the procedure is a useful adjunct to the clinical and roentgenographic evaluation of patients with acute abdominal pain.

Acute Disease↗