Biomedical subjects

G De Matteis

Publications and source records attributed to G De Matteis.

21 records · Page 2Linked to original sources

PubMed1989

Fluorescence studies of the aged erythrocyte membranes.

The most important purpose of this research is to characterize by means of fluorescence polarization the structural and functional changes which occur in the membrane of the human erythrocytes during aging process. Our results provide evidence of a significant increase of membrane fluidity in the deep lipid core and in the lipid/protein boundary, in the aged erythrocytes. These features are associated with a rigidity of the membrane surface, as revealed by the anisotropy increase of a specific probe suitable for monitoring the membrane protein behaviour. These modifications could be considered as one of the mechanisms which contribute to alter erythrocyte rheological properties sufficiently to be recognised and removed within circulation.

Erythrocyte Aging↗

PubMedDate not supplied

Sumatriptan and cerebral blood flow velocity changes during migraine attacks.

Transcranial Doppler studies on the effects of sumatriptan on cerebral hemodynamics have shown conflicting results. We evaluated blood flow velocity changes in 21 patients suffering from migraine with (n = 4) or without aura (n = 17) during a spontaneous attack, before and after treatment with sumatriptan. Flow velocity in the internal and external carotid, middle cerebral, and basilar arteries was measured by means of transcranial Doppler. During the attack, measurements were taken before subcutaneous sumatriptan injection, then after 30 minutes, 2 hours, and 24 hours. An additional measurement was taken 1 week later, in a headache-free state. We found a significant reduction of flow velocity during the attack in the middle cerebral artery on both sides (P < 0.05). After sumatriptan administration, flow velocity increased in the internal carotid artery on both sides (P < 0.05) and in the middle cerebral artery on the headache side (P = 0.0001), but not in the external carotid and basilar arteries (P > 0.05). Flow velocity changes may reflect the vasodilation present at the onset of the migraine attack followed by vasoconstriction in the internal carotid and middle cerebral arteries after sumatriptan treatment. Since vasoconstriction occurs in responders and nonresponders to treatment, it is unlikely to be the primary mechanism by which sumatriptan relieves headache.

Adolescent↗

PubMedDate not supplied

Erythrocyte membrane fluidity in subjects affected with reversible ischemic attacks (RIA).

It is well recognized that in subjects with cerebrovascular disease (CVD), changes in hemorheological properties may occur in about 50% of the patients. This paper concerns a study on microhemorheological perturbations of the erythrocyte membranes in a group of 20 RIA's patients, treated with Pentoxifylline. At the admission of the subjects to the study a trend to an increased whole blood viscosity and erythrocyte aggregation was associated to alterations of membrane fluidity analyzed by means of the fluorescent probes in the patients with respect to the controls. At the end of pharmacological treatment and wash-out, our data indicate a clear modification in erythrocyte membrane which results improved. Our results underline how the improvement of the erythrocyte membrane fluidity, induced by pentoxifylline, is a basic factor of blood flow in the microcirculation.

Erythrocyte Membrane↗