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Biomedical subjects

C Fieschi

Publications and source records attributed to C Fieschi.

At least 109 records · Page 6Linked to original sources
PubMed1991

Effect of stress on cardiovascular regulation in neurological diseases with dysautonomia.

Ten patients with Multiple Sclerosis (MS) and ten with Myotonic Dystrophy (MD) underwent an evaluation of cardiovascular reflexes by classic tests, tilt table test and mental stressors. Sympathetic and parasympathetic changes were detected by classical tests in MS patients. Mental stressors appeared able to reveal blood pressure control impairment in MD patients. Lower differential blood pressure was observed during mental stressors administration in MS with brainstem lesions at MRI.

Adult↗
PubMed1991

[Cerebral vascular damage in hypertension].

Hypertensive vascular lesions in the brain include increased formation of atheroma, lacunae and lacunar infarctions, atherothrombotic brain infarction and vascular dementias such as multi-infarct dementia and Binswanger's disease. Hypertension is also associated with an increased risk of intracerebral and subarachnoid hemorrhage. Reduction of arterial pressure with antihypertensive agents can prevent the occurrence and limit the extent of stroke.

Cerebrovascular Disorders↗
PubMed1991

Monosialoganglioside GM1 in cerebral ischemia.

In vitro studies have shown that monosialoganglioside GM1 reduces excitatory amino acid-related neurotoxicity by limiting the downstream consequences of abusive excitatory amino acid receptor stimulation, while enhancing neuronotrophic factor action in a variety of neuronal cell types. Systemic administration of GM1 appears to be efficacious in reducing acute nerve cell damage and in facilitating medium- and long-term functional recovery after brain injury. Although the mechanism of action remains unclear, it appears likely that GM1 protective effects in the acute injury phase are at least in part due to the attenuation of excitotoxicity, while the long-term functional recovery might reflect GM1 potentiation of neuronotrophic factors. The potential therapeutic efficacy of GM1 administration in different conditions in humans, as suggested by pioneer clinical studies, is reviewed. Further larger, randomized, double-blind clinical studies are necessary to define the therapeutic efficacy.

Brain Ischemia↗
PubMed1991

Controlled clinical trials in stroke.

Reasons for the unsatisfactory number and reliability of most trials on the pharmacological treatment of acute cerebral ischemia are reviewed, focusing mainly on the clinical aspects of the issue. The opportunity of early intervention, supported by current pathophysiological hypotheses, is recognized. Past and recent Italian trials on ischemic stroke patients evaluated and treated within the first 6 h from onset are reported, also mentioning the results of a study including early cerebral angiography and SPECT (Single Photon Emission Computed Tomography). Early fibrinolytics associated to brain protecting agents are regarded as the future choice in clinical trials of acute cerebral ischemia.

Cerebrovascular Disorders↗
PubMed1991

Tumour necrosis factor-alpha synthesis by cerebrospinal-fluid-derived T cell clones from patients with multiple sclerosis.

T cell clones derived from cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) were analysed for their ability to produce interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2) and interleukin-4 (IL-4). The CSF-T clones were compared for their ability to produce cytokines with autologous peripheral T clones and with liver-infiltrating T cell clones from patients with chronic active hepatitis. IL-4 production was also compared with that by peripheral T clones derived from atopic patients. All the CSF-T clones (both CD4+ and CD8+) produced large amounts of IFN-gamma and particularly of TNF-alpha. These cytokines were synthesized in significantly larger amounts by CSF T clones than by reference clones. Moreover, they were capable of secreting IL-2, but not IL-4. We conclude that the CSF-CD4+ T clones could constitute a subset with functional properties similar to those of T helper 1 (Th1)inflammatory cells of the mouse; and that the large amounts of TNF produced by CSF T cell clones strongly suggest a significant role for this cytokine in MS immunopathogenesis.

Adult↗
PubMed1990

Repeated electroconvulsive shock increases glial fibrillary acidic protein, ornithine decarboxylase, somatostatin and cholecystokinin immunoreactivities in the hippocampal formation of the rat.

Rats were submitted to single or repeated (7 days, one session for each day) sessions of electroconvulsive shock. A computer-assisted morphometric and microdensitometric analysis of glial fibrillary acidic protein-, ornithine decarboxylase-, somatostatin- and cholecystokinin-like immunoreactivities was performed in the hippocampal formation and other brain areas. The results of the study showed a significant increase of the intensity of the immunostaining for glial fibrillary acidic protein, ornithine decarboxylase, somatostatin and cholecystokinin in the hippocampal formation and distinctively in the dentate gyrus following repeated, but not single, electroconvulsive shock. No significant change was found in the number of somatostatin- and cholecystokinin-like immunoreactive cell bodies in any hippocampal subregion and in the number of glial cells in the hilus of dentate gyrus in rats treated with single or repeated electroconvulsive shock. It is a distinct possibility that the observed increase in the content of the neuropeptides in the hippocampal formation reflects a compensatory response of the brain to seizure-inducing stimuli and that such an increase may play a role in the therapeutic effect of electroconvulsive shock.

Animals↗
PubMed1990

Cerebral blood flow and plasma volume during hyperglycemia in the conscious rat.

Cerebral blood flow (CBF) and cerebral plasma volume (CPV) were measured under steady-state hyperglycemic conditions in the hemispheres and brainstem-cerebellum of conscious rats. There groups of hyperglycemic animals each having a different level of plasma glucose concentration, 25, 33.3, 44.4 mmol/l, and a normoglycemic control group were studied. CBF was not affected at the hyperglycemic levels of 25 and 33.3 mmol/l. Mean hemispheric and brainstem-cerebellum CBF values appeared lower than in controls at the highest glycemic level although the differences were not statistically significant. CPV was found to be unchanged at the hyperglycemic level of 25 mmol/l, while it was found to be increased in the hemispheres of the animals whose plasma glucose concentration had been elevated to 33.3 and 44.4 mmol/l. The results of the study do not support the claim that hyperglycemia may enhance ischemic brain injury by reducing CBF.

Animals↗
PubMed1990

Serum lipoprotein pattern variations in dementia and ischemic stroke.

Blood levels of triglycerides, total cholesterol, isolated lipoprotein fractions (VLDL-LDL- and HDL-cholesterol) and apoproteins (Apo-A1 and Apo-B) were examined in multi-infarct dementia, senile dementia of the Alzheimer type, ischemic stroke associated with carotid atherosclerosis and in control subjects. Forty patients divided into 10 consecutive patients for each group were studied. Alzheimer patients showed mean total cholesterol and Apo-B values significantly higher than control subjects. Apo-B was significantly higher in stroke patients than in controls. The mean lowest HDL-cholesterol (HDL-c) value was observed in stroke patients. No significant differences in mean HDL-c levels were found between patients with multi-infarct and Alzheimer dementia.

Aged↗
PubMed1990

Circadian variation in the frequency of ischemic stroke.

The frequency of myocardial infarction and sudden death is increased between 6 AM and noon. To determine whether the same is true for the onset of ischemic stroke, we studied 426 consecutive patients within 12 hours after the onset of their first hemispheric stroke. The frequency of onset of hemispheric stroke was significantly (p = 0.0001) higher from 6:01 AM to noon (56.1%) than from 12:01 PM to 6 PM (20.2%), from 6:01 PM to midnight (8.2%), and from 12:01 AM to 6 AM (15.5%). The identification of periods of high risk for vascular events may have important therapeutic implications, such as matching drug effects with vulnerability.

Aged↗
PubMed1990

Predictive value of brain perfusion single-photon emission computed tomography in acute ischemic stroke.

We investigated 32 patients with completed ischemic stroke less than or equal to 6 hours after the onset of symptoms by means of computed tomography, cerebral angiography, and technetium-99m-labeled hexamethylpropyleneamine oxime single-photon emission computed tomography to study cerebral blood flow. Follow-up computed tomography and cerebral blood flow studies were performed 1 week and 1 month after admission. Poor outcome at 1 month was evident in 18 (78%) of the 23 patients with severe neurologic deficit on admission and in 11 (92%) of the 12 patients with severe hypoperfusion in the affected hemisphere on admission. All 10 patients with severe impairment of both neurologic status and cerebral blood flow had a poor outcome at 1 month. We detected severe hypoperfusion in patients with large lesions on computed tomograms or cerebral artery occlusions on angiograms. Cerebral blood flow had increased at the 1-week follow-up despite different clinical outcomes. Our data provide evidence that early evaluation of cerebral blood flow with single-photon emission computed tomography is useful to detect subgroups of patients with different clinical outcomes during the acute phase of ischemic stroke.

Brain Ischemia↗
PubMed1990

Serial study of gadolinium-DTPA MRI enhancement in multiple sclerosis.

We performed serial baseline and gadolinium (Gd)-DTPA-enhanced MRI in 4 patients with definite multiple sclerosis. Studies were performed every month for a total of 4 scans. We obtained short TR/short TE sequences at 10 and 60 minutes after Gd-DTPA injection. All patients had multiple hyperintense lesions seen on baseline MRI with long TR/short and long TE. There was Gd-DTPA enhancement in new, enlarging, and preexisting lesions that were unchanged in size. The enhancing lesions were always seen on T2-weighted images. There was no difference in enhancement between the 10- and 60-minute studies. Six of 85 preexisting lesions enhanced whereas all new or enlarging lesions enhanced. Enhancement persisted in only 1/3 of the new or enlarging lesions, suggesting that MR enhancement is a transient phenomenon due to local temporary blood-brain barrier breakdown. Our data indicate that Gd-DTPA enhancement monitoring is more sensitive than unenhanced MRI for detecting disease activity in MS.

Adult↗
PubMed1990

Internal borderzone infarction following acute middle cerebral artery occlusion.

In 36 patients suffering acute middle cerebral artery (MCA) occlusion, we studied the angiographic findings within 6 hours of the ictus and the chronic CT results at 3 months. Seven patients suffering distal pial MCA branch occlusion developed a pattern of internal borderzone infarction on follow-up CT. Carotid artery or carotid siphon stenosis or occlusion was absent in all seven. Proximal MCA branch occlusions, prior to the origin of the lenticulostriate arteries, were associated with extensive cortical and deep infarction in the entire MCA territory in 14 patients. There was proximal carotid artery or siphon stenosis or occlusion in 12 of these 14 patients. The remaining 15 patients showed a mixture of proximal and distal MCA occlusions and patchy ischemic damage in the MCA territory. There were no cases of superficial cortical watershed infarction. These data show that internal borderzone infarctions may result from intracranial MCA branch occlusions alone and need not be associated with hemodynamic alterations due to large vessel extracranial disease.

Acute Disease↗
PubMed1990

Pathophysiology of ischemic brain disease.

In this article, we review and discuss the pathophysiology of brain ischemia, focusing on requirements of cerebral metabolism, biochemical characterization of the energy reserve, and autoradiographic and tomographic methods for in vivo evaluation of cerebral blood flow and metabolism. We propose new therapeutic strategies for the management of the acute phase of stroke, based on diagnostic protocols that include clinical evaluation, noninvasive study of neck and intracranial arteries, brain computed tomography, and single-photon emission computed tomography. The ideal therapeutic trial should combine early thrombolysis and active brain protection against those biochemical mechanisms leading to irreversible neuronal damage.

Animals↗
PubMed1989

Systemic hypertension as a treatable risk factor for cerebrovascular disease.

It has long been established that hypertension is the major risk factor for stroke. Three Italian studies have been reviewed in order to examine different aspects of the problem. In the first study, the role played by the systolic, diastolic and systodiastolic components of hypertension in causing atherosclerotic damage of extracerebral and intracerebral arteries was examined. At the extracranial level, a significant correlation between systolic hypertension and atherosclerotic lesions was evident. The second study evaluated the risk of major stroke, myocardial infarction and death in patients with transient ischemic attacks and reversible ischemic neurologic deficits. Possible prognostic predictors of these events were thoroughly considered: Cumulative survival with the multivariate Kaplan-Meier analysis was significantly lower in hypertensive than in normotensive subjects, particularly for cerebral deaths and for all deaths. The third study was aimed at assessing the risk factors for transient ischemic attacks and stroke in young adults. Again, hypertension emerged as a fundamental risk factor, significantly more frequent in the subgroup of older patients than in the younger subgroup.

Age Factors↗
PubMed1989

Ischaemic supratentorial stroke: angiographic findings in patients examined in the very early phase.

Eighty patients were studied by angiography within 6 h of an ischaemic stroke. Angiography was carried out with digital equipment and was usually limited to the vascular territory responsible for the neurological deficits. In 12 of 19 patients with internal carotid occlusion, the contralateral side was also studied. The angiographic abnormalities were classified as extracranial, intracranial, and combined extra and intracranial. The data show a high incidence (66%) of occlusive pathology of intracranial arteries, either isolated or associated with a significant presence of a potential embolic source (85%), and a high incidence of carotid occlusions located at the cervical segment (8 of 19). These observations suggest that most strokes are occlusive in origin.

Aged↗
PubMed1989

Occlusion of the extracranial internal carotid artery in the acute stroke; angiographic findings within 6 hours.

We studied by angiography 80 patients within 6 hours from the onset of symptoms of supratentorial ischaemic stroke. Occlusion of the internal carotid artery in the extracranial segment was found in 19 patients, at the bifurcation in 11 and at the cervical level in 8. While in the chronic phase of stroke, internal carotid artery occlusion in the cervical segment is an uncommon angiographic finding, we found a high frequency of occlusion at this level (8 out of 19) in our patients. Cervical segment occlusion may be due to a dissecting aneurysm or to an intracranial carotid artery occlusion (embolic or atherothrombotic) with subsequent migration of the clot down to this level. A direct embolic occlusion may be postulated as well.

Aged↗