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Biomedical subjects

E Tedeschi

Publications and source records attributed to E Tedeschi.

32 records · Page 2Linked to original sources
PubMed1995

Heterogeneous cerebral glucose metabolism in normal pressure hydrocephalus.

The regional cerebral metabolic rate for glucose (rCMRglu) has never been investigated in large consecutive groups of patients with normal pressure hydrocephalus (NPH), a potentially treatable form of dementia with an unpredictable outcome after shunt surgery. Using PET and 18F-2-fluorodeoxyglucose, rCMRglu was studied in 18 patients who fulfilled hydrodynamic criteria for NPH and in whom a biopsy of the frontal cortex was obtained. When compared with an age matched group of 11 healthy subjects, the patients with NPH showed a significant rCMRglu reduction in all cortical and subcortical regions of interest. Individual metabolic patterns, however, disclosed a large topographical heterogeneity. Furthermore, histopathological examination identified Alzheimer's disease or cerebrovascular disease in six cases, and no parenchymal disease or non-specific degenerative processes in the remaining 12. After separating the patients according to the histological diagnosis, the rCMRglu patterns were still heterogeneous, the abnormalities ranging from focal to diffuse in both subgroups. After shunt operation, 11 patients did not improve or worsened clinically. Six patients improved; of those, two had Alzheimer changes and two cerebrovascular changes in their biopsy. The metabolic pattern of these six patients did not differ from the rest of the NPH group. The results indicate that the NPH syndrome may be non-specifically associated with different degenerative disorders. The metabolic heterogeneity, together with the heterogeneous histopathological findings, indicate the necessity of reevaluating the pathogenesis of the NPH syndrome, and may account for the high variability in the success rate of shunt surgery series.

Aged↗
PubMed1995

Regional cerebral blood flow and neuropsychological performance in a Danish family with X-linked bulbo-spinal neuronopathy.

Regional Cerebral Blood Flow (rCBF) measurements and neuropsychological evaluation were performed in 6 patients from a Danish family affected with X-linked Bulbo-Spinal Neuronopathy (XBSN). This inherited form of motor neuron disease (MND) has been shown to affect various functions within the nervous and the endocrine systems. We investigated the possibility that focal or diffuse cortical deficits, already demonstrated in MND, were present in XBSN. The global CBF values of the patients, when compared to age- and sex-matched healthy controls, were found reduced, but no focal rCBF alterations, nor increased regional side-to-side asymmetry were observed. The neuropsychological evaluation showed no cognitive impairments. We conclude that cortical perfusion and cognitive functions are not significantly altered in XBSN.

Adult↗
PubMed1994

[Scintigraphy with gallium-67 citrate in patients with AIDS: pathologic extrapulmonary uptake].

67Gallium citrate can accumulate in different inflammatory and neoplastic lesions. The mechanisms of 67Gallium uptake in abnormal tissue are still partially unknown and the tracer is considered a nonspecific indicator of disease. In AIDS patients, 67Gallium citrate is used in the diagnosis and characterization of opportunistic pulmonary infections and especially of Pneumocystis carinii pneumonia. From June 1989 through December 1992 in our Department 140 67Gallium scans were performed on 103 AIDS patients, referred for evaluation of pulmonary symptoms. All studies were carried out 72 hours after i.v. administration of 185 MBq 67Gallium citrate, with anterior and posterior views of head, chest and abdomen. The images were evaluated with conventional diagnostic criteria and site, number and intensity of abnormal foci of extrapulmonary uptake were recorded. Abnormal extrapulmonary uptake was found in 17 patients (12%): gastric (3, two of which also exhibited abnormal intestinal uptake), esophageal (1) hepatic (1), intestinal (2) renal (4), nodal (3), ocular (1), cutaneous (1), sinusal (1) localizations. In all cases clinical, endoscopic, bioptic or microbiological demonstration of the possible cause of 67Gallium uptake was obtained. An intriguing finding in our series was the lower incidence of gastric uptake (two patients with miliary tuberculosis and one patient with gastric candidiasis) than in the literature. This finding could be explained by clinical and epidemiologic differences between different patient populations. However, the scan interval after tracer administration should be also taken into account, since in our study scans were always performed at 72 hours, while in other series the interval ranged 24-48 hours. The relatively high incidence of abnormal extrapulmonary uptake confirms the opportunity of whole body exploration after 67Gallium administration in the patients with such multisystemic disease as AIDS, even when the patients are referred mainly for respiratory problems.

Acquired Immunodeficiency Syndrome↗
PubMed1992

The influence of haematocrit and blood glucose on cerebral blood flow in normal and in diabetic rats.

Cerebral blood flow (CBF) was measured at varying haematocrit values in 8 streptozotocin-diabetic and in 7 control rats using the intracarotid 133Xe technique. A hyperbolic relationship between CBF and haematocrit was established for the individual rats in both groups. Diabetic animals showed a preserved CBF response to changes to haematocrit. In 10 normal rats, CBF was measured during acute hyperglycaemia induced by intraperitoneal glucose injection. A significant, inverse correlation was found between CBF and blood glucose. We conclude that the CBF response to changes in haematocrit and thereby in pO2 is preserved in experimental diabetes. Secondly, in acute hyperglycaemia CBF varies inversely with blood glucose, by mechanisms not fully understood.

Animals↗
PubMed1991

Dopamine D1 and D2 receptors mediate opposite functions in seizures induced by lithium-pilocarpine.

The effect of selective dopamine receptor blockade on epileptic activity was tested in rats, using the lithium-pilocarpine seizure model. One day after lithium pretreatment, systemic administration of the dopamine D1 antagonist, SCH 23390, prevented the convulsive activity induced by either 10 or 15 mg/kg of pilocarpine in a dose-dependent manner as revealed by behavioral and electroencephalographic alterations. No anticonvulsant effect was observed when SCH 23390 was injected at the same time as lithium and 24 h prior to pilocarpine. Furthermore, the D2 antagonists, raclopride and haloperidol, potently reduced the threshold for convulsions induced by 10 mg/kg of pilocarpine, following lithium pretreatment. Neither dopamine D1 nor D2 antagonists altered the limbic stereotypies induced by pilocarpine, supporting the view that the dopamine system is primarily involved in the mechanisms of convulsion generation and seizure spreading. These results indicate that dopamine receptor subtypes exert opposite functions on the regulation of convulsive activity.

Animals↗
PubMedDate not supplied

Congenital agenesis/aplasia of the internal carotid arteries: MRA and SPECT findings.

Single photon emission CT (SPECT) and MRI and MR angiography studies were performed in a patient with right internal carotid artery (ICA) agenesis, left ICA aplasia, and multiple associated vascular abnormalities identified with digital subtraction angiography. Magnetic resonance angiography provided an excellent depiction of the extra- and intracranial vascular abnormalities. No evidence of brain lesions or perfusion defects was demonstrated with MRI and SPECT, despite the markedly altered vascular anatomy.

Carotid Arteries↗
PubMedDate not supplied

Behavior of calf blood flow in normal subjects and in patients with intermittent claudication during a 24-h time span.

Calf basal resting and reactive hypercemia blood flow were measured at 4-h intervals during a day in fifteen healthy subjects and in fifteen patients with intermittent claudication by means of a venous occlusion plethysmograph. Mathematical-statistical analysis of the data failed to demonstrate circadian periodicity of calf blood flow in healthy subjects, but proved the existence of a 24-h rhythm of calf basal resting and reactive hyperemia blood flow in patients with intermittent claudication. This different behavior of calf blood flow can be understood if one considers that in healthy subjects the voluntary muscles in the extremities have a blood supply which can be instantaneously adjusted over a large area. In patients with peripheral arterial disease, on the other hand, the vascular responses in voluntary muscles of the limbs to various endogenous or exogenous stimuli are impaired and reduced. The circadian rhythm observed in patients with intermittent claudication has early evening peaks and a nocturnal trough with a nadir occurring after midnight and before 0400. This rhythm displays marked similarities with those of all other circulatory values. As to the mechanism of rhythm, it is hard to decide whether or not it has an independent endogenous origin. It is known that many of the circulatory variables are interrelated and that some are clearly related to other circadian rhythms. Perhaps the rhythmic reduction of limb blood flow which occurs during the night is the mechanism underlying the nocturnal pain of subjects with limb ischemia by peripheral arterial disease.

Adult↗
PubMedDate not supplied

Intracerebral haemorrhage: criteria for prognosis on the grounds of clinical and CT data.

The Authors report analyses on 83 cases of brain haemorrhage which were conducted over a period of 6 years. On the basis of previous studies made by the same authors, a selection was made from patients whose survival index rating did not exceed 8.1. These patients were treated only with medical and reviving therapies. In this work we attempt to formulate some considerations regarding the prognosis of brain haemorrhage on the basis of clinical and tomodensitometric data.

Cerebral Hemorrhage↗