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Biomedical subjects

C Fieschi

Publications and source records attributed to C Fieschi.

At least 181 records · Page 10Linked to original sources
PubMed1979

Osmotic opening of the blood-brain barrier and local cerebral glucose utilization.

The effects of osmotic opening of the blood-brain barrier (BBB) on local cerebral glucose utilization (LCGU) were studied in rats with the carbon 14-deoxyglucose method. The BBB was opened to Evans blue dye by unilateral carotid artery perfusion with hypertonic mannitol solution. (14C)-Deoxyglucose was injected 15 minutes or two to three hours later. Osmotic opening of the BBB resulted in focal areas of intense LCGU in affected areas of the perfused hemisphere. In the contralateral hemisphere, glucose utilization was diminished, especially in cerebral cortical areas. The effects were reversible. LCGU was normal in both hemispheres when permeability to Evans blue returned to normal two to three hours after carotid artery perfusion. In 3 of 5 experiments the administration of high doses of intravenous diazepam immediately following carotid artery perfusion with mannitol prevented an increase in LCGU in the perfused hemisphere but did not prevent lowering of LCGU in the contralateral hemisphere. Increased LCGU following osmotic opening of the BBB was not accompanied by a rise in local cerebral blood flow as measured by the iodoantipyrine method. Blood flow was, in fact, significantly decreased.

Animals↗
PubMed1978

Circulatory and metabolic aspects of cerebral ischemia in experimental animals and in men.

In normal conditions, there is a precise link between regional metabolism and blood flow in the brain. In pathological states there may be an uncoupling between CBF and metabolism, due to many mechanisms. In particular, anaerobic glycolisis, membrane depolarization, and altered neurotransmitter release are relevant for the final damage of the tissue. Postischemic recovery was analyzed in experiments with 14C-deoxyglucose. In men, the noninvasive approach with 15O by inhalation allowed the determination of regional oxygen utilization. In TIAs, there is a chronic ischemic condition, while in strokes there is often a relative luxury perfusion.

Animals↗
PubMed1977

Superior orbital fissure syndrome. Review of 130 cases.

Superior orbital fissure syndrome is a symptomatologic complex, consisting of retroorbital pain, paralysis of extraocular muscles, impairment of first trigeminal branches and frequent involvement of the optic nerve. From a review of 130 published cases including two personal observations, it appears that the clinical subdivisions and the several eponymic differentiations of this syndrome are unjustified on the basis of etiologic, therapeutic and prognostic elements. Only the presence--or absence--of optic signs may allow to hold the clinically useful distinction between the often 'benign' superior orbital fissure syndrome without optic nerve involvement, and the orbital apex syndrome where orbital exploration may be recommended. This review concludes that repeated neurosurgical and neuroradiologic investigations--with the exceptions of carotid angiography and orbital phlebography--can be avoided in such cases.

Aged↗
PubMed1977

Assessment of regional cerebral blood flow by continuous carotid infusion of krypton-81m.

In order to obtain functional images of brain perfusion, we exploited a new concept, which is to take advantage of the short half-life of a radioactive tracer. Under continuous intracarotid infusion of a solution of Kr-81m (T1/2 = 13 sec; produced from its parent, 4.6-hr Rb-81), this tracer will never reach equilibrium within the brain because of the rapid radioactive decay. Its distribution will therefore reflect regional arrival of the nuclide, indicating regional cerebral blood flow rather than volume. During continuous infusion of Kr-81m, perfusion images can be obtained by simply collecting counts with a gamma camera and recording on Polaroid film. The procedure is readily repeatable in order to get images in multiple veiws or to follow minute-by-minute changes of cerebral perfusion.

Aged↗
PubMed1976

Effect of amantadine on drug-induced parkisonism: relationship between plasma levels and effect.

Amantadine, administered at a dose of 200 mg/day, antagonized the extapyramidal symptomatology induced by neuroleptic drugs in fifteen psychiatric patients. Steady-state levels were reached within 4-7 days of treatment. Individual plasma levels ranged from 200-900 ng/ml. Apparent plasma half-lives varied from 10-28.5 h with an apparent VD of 200-400 litres. A significant relationship was found between the plasma levels of amantadine and the effects on the extrapyramidal symptomatology. The data suggest a direct effect of amantadine on dopaminergic receptors.

Adult↗
PubMed1974

Regional cerebral blood flow and intraventricular pressure in acute head injuries.

Twelve patients who were comatose after head injuries were studied with serial determinations of regional cerebral blood flow, jugular PO(2) tension, and intraventricular pressure. These determinations began a few hours after the injury, and were followed throughout the clinical course. Diffuse derangement of cerebral vasomotor regulation is confirmed after severe head trauma, which may contribute to deterioration and poor prognosis, and which indicates a need for therapeutic maintenance of rich oxygenation, hyperventilation with moderate hypocapnia, and steady blood pressure. Continuous recording of IVP (eventually sensitized by fluid infusion or CO(2) inhalation tests) may give an early indication of the subsequent clinical state and may suggest the need to submit the patients to further investigative and therapeutic procedures.

Acute Disease↗