Biomedical subjects

S T Onesti

Publications and source records attributed to S T Onesti.

22 records · Page 2Linked to original sources

PubMed1990

Clinical versus subclinical pituitary apoplexy: presentation, surgical management, and outcome in 21 patients.

A retrospective review of 16 consecutive patients with pituitary apoplexy treated over a 10-year period is reported. Eight men and 8 women (mean age, 48 years) underwent transsphenoidal decompression after an average duration of symptoms of 19 days. The diagnosis of pituitary apoplexy was made by the sudden onset of headache (88%), nausea (56%), or meningismus (13%), with or without visual disturbances (75%), in the setting of a sellar tumor on computed tomographic or magnetic resonance imaging scans. Thirteen of 16 patients showed significant improvement of symptoms after surgery (average follow-up, 2.5 years). In addition, 5 patients with clinically silent yet extensive pituitary hemorrhage were treated. Although extensive pituitary hemorrhage often produced fulminant apoplexy, it also presented insidiously over many days with few, if any, clinical signs. Rapid diagnosis, endocrine replacement, and transsphenoidal decompression constituted effective therapy. Magnetic resonance imaging (after at least 12 hours of symptoms) was superior to computed tomography in detecting hemorrhage.

Adenoma↗

PubMed1989

The effects of norepinephrine depletion on cerebral blood flow in the rat.

Cerebral blood flow (CBF) was measured by [14C]butanol indicator fractionation in 10 rats given intraventricular injections of 6-hydroxydopamine (6-OHDA) compared to 8 saline-injected controls. Rats treated with 6-OHDA displayed an 83% reduction in cortical norepinephrine (NE) levels. CBF was significantly increased in 6-OHDA-treated rats compared to controls (average whole brain blood flow of 126.0 +/- 8.3 and 97.1 +/- 10.6 ml.min-1.10(-2)g-1 respectively, P less than 0.05). These studies suggest that noradrenergic innervation of the brain and cerebral microvasculature exerts a moderating effect on resting CBF.

Animals↗

PubMed1989

Cerebral revascularization: a review.

A review of the development and current methods of surgical revascularization of the cerebral circulation is presented. In addition to the conventional superficial temporal artery to middle cerebral artery (STA-MCA) bypass, the techniques of interposition vein grafting and vertebrobasilar revascularization are discussed. The results and implications of the International Cooperative Study are reviewed. Extracranial-intracranial (EC-IC) bypass grafting remains an essential procedure in the treatment of many cerebrovascular conditions, including Moya Moya disease and giant intracranial aneurysms. The efficacy of interposition vein grafts, as well as the EC-IC bypass in the treatment of vertebrobasilar insufficiency, acute cerebral ischemia, cerebral vasospasm, and multi-infarct dementia, remains to be determined. Several alternative revascularization procedures, including proximal MCA anastomosis and omental transposition, are in development.

Brain Diseases↗

PubMed1986

Somatostatin immunocytochemistry in the rabbit retina.

In previous work, radioimmunoassay was used to document the presence of somatostatin-like immunoreactive material in the rabbit retina. The present study was undertaken to determine the cellular localization of that material by light microscopic immunocytochemistry. Rabbit retinas were fixed by immersion in paraformaldehyde-lysine-periodate and reacted, either as whole retinas or as 50 microns Vibratome cross-sections, with an antiserum directed against somatostatin-14. Consistent staining of neuronal perikarya was seen only in the retinas of rabbits that had been pretreated with intravitreal injections of colchicine. Specifically stained cell bodies are present in the ganglion cell layer; the cells give rise to fibers in both the innermost and outermost sublaminas of the inner plexiform layer. In retinal whole mounts, the cells possess two or three primary dendrites with sparse branching. The dendritic fields are up to 1 mm in diameter, and adjacent dendritic fields overlap. Many cells have a thin varicose process arising from the soma or a proximal primary dendrite; these processes branch repeatedly within the retina and resemble intraretinal axons. The somatostatin-reactive cells may be associational ganglion cells or displaced amacrine cells; it is less likely that they are ganglion cells with axons projecting to the brain.

Animals↗