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Biomedical subjects

C Fieschi

Publications and source records attributed to C Fieschi.

At least 163 records · Page 9Linked to original sources
PubMed1985

Metabolic and kinetic considerations in the use of [125I]HIPDM for quantitative measurement of regional cerebral blood flow.

The metabolic degradation and the kinetics of the cerebral uptake of N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-[125I]iodobenzyl)-1, 3-propanediamine ([125I]HIPDM) have been studied in conscious, adult male Sprague-Dawley rats to determine its suitability as a tracer for the quantitative measurement of regional CBF (rCBF). rCBF was calculated by the indicator fractionation and the tissue equilibration methods in experiments of different durations up to 1 h. The values of rCBF obtained with [125I]HIPDM were compared with those obtained in concurrent measurements with [14C]iodoantipyrine in the same animals. Results of the experiments demonstrate that [125I]HIPDM is an inadequate tracer for use with the indicator fractionation method and that any method that employs [125I]HIPDM for the determination of rCBF must take into account its metabolic degradation, diffusion limitations, and bidirectional flux across the blood-brain barrier. With the tissue equilibration method, consistent determinations of rCBF may be possible with [125I]HIPDM by measurement of the time course of its concentration in arterial blood, corrected for the presence of 125I-labeled metabolic products, and its concentration in the brain at any time up to 1 h after its administration. The method may be adapted to measure rCBF in humans by means of single-photon emission tomography with [123I]HIPDM.

Animals↗
PubMed1985

Peripheral white blood cell count in cerebral ischemic infarction.

Peripheral white blood cell (WBC) count was determined in 95 patients with ischemic cerebral infarction 3 days after the onset of the stroke. At this time, higher WBC counts were found in patients with more severe neurological impairment and larger infarct size. A relationship between increase of WBC count and poor clinical outcome was also demonstrated. The elevation of peripheral WBC count observed soon after cerebral infarction reflects the degree of the inflammatory response in the acute hase and seems to have a direct relationship with the extent of the local cerebral damage.

Aged↗
PubMed1985

Focal cerebral ischemia and migraine.

Consistent literature data on the cerebrovascular risk in migraineous patients are lacking. Available preliminary clinical data (Italian Cooperative Cross-Sectional Case-Control Study) suggest that migraine can hardly be considered a relevant pathogenetic associated risk factor of focal cerebral ischemia.

Adult↗
PubMed1983

Creutzfeld-Jakob disease in the province of Siena: two cases transmitted to monkeys.

Two cases of histopathologically documented Creutzfeldt-Jakob disease were observed in the same area of the province of Siena in 1974-1975. The transmission of the disease was obtained through brain homogenates and lymphnodes in one of the two cases. This confirms that the agent is present in other tissues besides the brain and underlines further the analogies between Creutzfeld-Jakob disease and scrapie.

Aged↗
PubMed1983

Mitral valve prolapse as a risk factor for TIA. A study with echocardiography and dynamic ECG.

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.

Adult↗
PubMed1983

Italian study of cerebral reversible ischemic attacks. II. The hematocrit and hemoglobin distribution and its relationship between clinical pattern and angiographic abnormalities.

A clinical and angiographic study was conducted in 360 patients with previous reversible ischemic attacks (RIAs) in order to verify the influence of hematocrit, hemoglobin and red cell count within the normal range in the clinical picture of cerebral infarction and its relationship with angiographic atherosclerosis. No significantly different distribution of the three parameters considered has been found according to the presence and the degree of atherosclerosis. On the contrary, our data have shown a significant correlation between levels of hematocrit, hemoglobin and red cell count and some clinical aspects of the RIA when angiographic atherosclerosis is present.

Adult↗
PubMed1983

[Hemorrheological changes in cerebrovascular disease].

Over the past ten years, several studies have outlined the importance of high blood viscosity as a pathogenetic factor in ischemic cerebrovascular diseases. Clinical studies have demonstrated that a high blood viscosity due to an elevated hematocrit (greater than 46%) increases the risk of cerebral infarction. Furthermore, in patients with high hematocrit, the cerebral blood flow seems to be lower than in controls and, by removing 200-250 ml of blood by venesection, the cerebral blood flow can be normalized. Several authors have therefore proposed that venesection may be used as a preventive measure in patients at risk for cerebral ischemia with high hematocrit. In addition, studies on experimental brain ischemia have shown that hemodilution reduces the size of the infarction. Therefore, hemodilution has been proposed as an effective measure in the treatment of acute cerebral ischemia. In conclusion, it seems that high blood viscosity is a risk factor in cerebral ischemia although its pathogenetic mechanisms and clinical importance are not yet completely clarified.

Blood Viscosity↗
PubMed1981

Effects of naftidrofuryl on local cerebral glucose utilization in the rat.

The effects of naftidrofuryl on local cerebral glucose utilization have been examined in 21 lightly restrained, conscious rats by means of the quantitative autoradiographic 2-deoxyglucose technique. Naftidrofuryl (15, 30, and 45 mg/kg, i.p.) did not significantly alter the rate of glucose utilization in any of the 29 gray matter or 4 white matter areas that were examined.

Animals↗
PubMed1981

Pathophysiology of cerebral blood flow in brain ischemia.

On the basis of findings obtained by means of both traditional and modern tomographic techniques, Authors discuss changes of cerebral blood flow (CBF) and metabolism in acute cerebral ischemia and chronic cerebral circulatory insufficiency. Drug effects on cerebral circulation and metabolism are examined and experiences with pentoxifylline, substance provided with haemorheologic action, are reported.

Brain Ischemia↗
PubMed1980

Circulating platelet aggregates: a chronic platelet activation in patients with transient ischaemic attacks.

Platelet hyperaggregability was tested in 62 TIA patients by means of the formalin fixing principle of Wu and Hoak. Compared to age-matched controls, the platelet aggregates ratio (PAR) was reduced from 0.99 +/- 0.04 SD to 0.807 +/- 0.14 SD. This means a highly significant increase of circulating platelet aggregates (CPA) in untreated TIA patients, regardless of the interval sinche the last attack (from 2 days to 1 year). PAR was especially reduced in patients with abnormal angiography (expressing pronounced cerebral or diffuse ATS) and it was possibly affected by previous antiplatelet treatment with ASA.

Aspirin↗
PubMed1980

Tomographic assessment of cerebral perfusion using a single-photon emitter (krypton-81m) and a rotating gamma camera.

Continuous carotid infusion of short-lived krypton-81m (t1/2 13 sec) yields an assessment of regional cerebral perfusion. This assessment can be obtained in three dimensions if activity is recorded with a rotating gamma camera and a computer to reconstruct krypton-81m distribution in tomographic sections. These showed several advantages over conventional views: (a) visualization of blood-flow distribution within brain structures (gray and white matter, basal ganglia); (b) more accurate location and evaluation of areas of relatively reduced or increased perfusion; (c) better definition of patterns of collateral circulation; (d) greater sensitivity and specificity in detecting and defining blood-flow changes during physiological activation studies. A limitation of the krypton-81m technique is its invasiveness. However, this study shows that the combination of new advances in radiochemistry with single-photon emission computed tomography may result in accessible methods for assessing, noninvasively and in three dimensions, the behavior of cerebral function in man.

Brain Diseases↗