Biomedical subjects
Publications and source records attributed to S Bernardi.
Fifty Flexi-Posts were cemented in extracted teeth and tested for tensile strength. The Flexi-Post was the most retentive post tested when compared with posts used in a similar study. The retention of the Flexi-Post became greater as the size of the post increased.
Explore the source record for details and available documents.
Regional cerebral blood flow, fractional oxygen extraction and oxygen metabolism have been measured in 34 patients after acute nonhaemorrhagic cerebral hemispheric infarction. Nine cases showed elevated oxygen extraction in the region of the early infarct, and these were the patients studied earliest after the onset of stroke. The results of serial studies to follow the evolution of the pathophysiology of acute stroke in these 9 patients are presented. The elevated oxygen extraction within the early infarct showed a significant reduction over the week following the onset of stroke. The reason for this fall in the fractional use of available oxygen varied in individual cases, and at the extremes was associated with a marked reduction in oxygen metabolism with a further small fall in residual blood flow, or a return of flow without recovery of oxygen metabolism. The significance of oxygen extraction in terms of potential viability of the tissue is discussed. The finding of a lower oxygen extraction in subcortical grey and white matter compared to cortex within the first hours or days of a major stroke is considered indicative of an earlier change from ischaemia to infarction in the deep tissues, probably related to the anatomy of the microvasculature. The interpretation of the results in the light of knowledge accumulated from studies of ischaemia in animals is presented, and problems imposed on data analysis by current limitations in positron emission tomography are discussed.
Data from ten patients with complex partial seizures who underwent positron emission tomography using the 15-0 inhalation technique are presented. Decreased flow and metabolism are noted in the hemisphere ipsilateral to the EEG focus, but, in patients with unilateral foci, bilateral changes in temporal cortex are detected. Other areas maximally affected include the basal ganglia, and the cerebellum. The possible role of anticonvulsant drugs in these findings is discussed.
The present study has been devoted to the analysis of 120 patients presenting with reversible focal cerebral ischemia without conventional signs of cardiopathy and/or relevant atherosclerotic disease. In 77% of the patients vascular risk factors, such as hypertension or hyperlipemia, were present. In 23% of the patients, no abnormal finding was discovered at clinical, hematochemical and cardiological examinations. In these patients a further cardiological evaluation was performed with echocardiography. Dynamic electrocardiography was performed in 52 patients. Echocardiography and dynamic electrocardiography revealed the occurrence of 6 cases of mitral valve prolapse (MVP), 2 cases of frequent premature ventricular beats, and 1 proximal atrial arrhythmia. All 6 cases of MVP were detected in the subgroups of patients without vascular risk factors. In our patients younger than 45 years, the relative frequency of MVP attains 21.5%. This study confirms that MVP has to be regarded as a risk factor for focal cerebral ischemia in young patients.
Explore the source record for details and available documents.
Regional cerebral blood flow and oxygen utilisation have been studied in 8 patients with brain tumours using continuous inhalation of C15O2 and 15O2 and positron emission tomography. The methods used to analyse the regional cerebral pathophysiology are presented. A relative uncoupling between oxygen consumption and blood flow was observed in all tumours as indicated by a decreased regional fractional extraction of oxygen (rOER). This suggest that a major proportion of these tumours had sufficient blood supply to meet oxygen metabolic demand. A decrease of blood flow in grey matter was found both in the affected and contralateral hemispheres of the brain. Matched reductions of flow and oxygen utilisation were observed in oedematous tissue.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.