Influence of Tacrine on Catecholamine Secretion in the Perfused Rat Adrenal Gland

The present study was designed to clarify whether tacrine affects the release of catecholamines (CA) from the isolated perfused model of rat adrenal gland or not and to elucidate the mechanism of its action. Tacrine (3 X 10(-5)~3 X 10(-4) M) perfused into an adrenal vein for 60 min inhibited CA secretory responses evoked by ACh (5.32 X 10(-3) M), DMPP (a selective neuronal nicotinic agonist, 10(-4) M for 2 min) and McN-A-343 (a selective muscarinic M1-agonist, 10(-4) M for 2 min) in relatively dose- and time- dependent manners. However, tacrine failed to affect CA secretion by high K+ (5.6 X 10(-2) M). Tacrine itself at concentrations used in the present experiments did not also affect spontaneous CA output. Furthermore, in the presence of tacrine (10(-4) M), CA secretory responses evoked by Bay-K-8644 (an activator of L-type Ca2+ channels, 10(-4) M), but not by cyclopiazonic acid (an inhibitor of cytoplasmic Ca2+-ATPase, 10(-4) M), was relatively time-dependently attenuated. Also, physostigmine (10(-4) M), given into the adrenal gland for 60 min, depressed CA secretory responses evoked by ACh, McN-A-343 and DMPP while did not affect that evoked by high K+. Collectively, these results obtained from the present study demonstrate that tacrine greatly inhibits CA secretion from the perfused rat adrenal gland evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors, but does fail to affect that by direct membrane-depolarization. It is suggested that this inhibitory effect of tacrine may be exerted by blocking both the calcium influx into the rat adrenal medullary chromaffin cells without Ca2+ release from the cytoplasmic calcium store, that is relevant to the cholinergic blockade. Also, the mode of action between tacrine and physostigmine in rat adrenomedullary CA secretion seems to be similar.

Cerebellar Pleomorphic Xanthoastrocytoma in an Infant: Case Report

Pleomorphic xanthoastrocytoma is a rare type of glioma and usually occurs in the superficial cerebral hemisphere of the patients under the age of 30 years. We report a case of pleomorphic xanthoastrocytoma in the cerebellum of a 3-month-old infant. This is an unusual case in view of location and age. The literatures concerning the clinicopathological aspects of this unusual pleomorphic xanthoastrocytoma are reviewed.

Anterior Decompression and Internal Fixation with Anterior Instrument and Surgical Titanium Mesh in Thoracolumbar Unstable Spine Injuries(Long-term Follow-up Results)

No abstract available.

Anterior Interbody Fusion Using Kaneda Device in Unstable Thoracolumbar Spinal Lesions

Recently anterior spinal device in the treatment of the unstable thoraco-lumbar spine has been used. We have experienced 11 patients of the unstable thoraco-lumbar spine, which were composed of 8 patients with burst fracture and 3 patients with tuberculous spondylitis. The 11 patients with neurological deficit were treated with an one stage anterior operation consisting of anterior decompression through vertebrectomy, realignment with Kanedae device. No patient showed neurologic deterioration after surgery. The anterior spinal instrumentation with Kaneda device afford enough stability to enable early ambulation with good alignment and solid fusion.

Anterior lnterbody Fusion using KANEDA Instrument in Tuberculous Spondylitis: Case Report

We reported 2 cases of tuberculous spondylitis and its treatment was improved with anterior interbody fusion by a KANEDA instrument. The patients were early ambulation without any complications and sequalaes.

Experience of Management of Unstable Thoraco-Lumbar Spine Using V.S.P(Variable Screw Placement) Plate

Fourteen consecutive patients underwent application of V.S.P(Variable Screw Placement) spinal plate between January 1989 and July 1989. Operative indications were spondylolisthesis, spinal stenosis, segmental instability, herniated disc with instability, pseudoarthrosis. unstable fracture, and failed surgery syndrome. Our patients consist of 8 cases of spondylolisthesis, 4 cases of fracture-dislocation, one case of spondylolysis with instability, one case of herniated disc(L1- 2 interspace). Overall results showed 36% excellent, 50% good, 7% fair, 7% poor. Two deep wound infections were observed. Screw alignment and the angular relationship of each screw to the spinal plate is considered as important technical factors in minimizing screw failure.