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Biomedical subjects

P Gaetani

Publications and source records attributed to P Gaetani.

At least 37 records · Page 2Linked to original sources
PubMed1996

A systemic "dumb-bell" haemangiopericytoma.

Systemic haemangiopericytoma is a rare soft tissue tumour originating from pericytes which are contractile pericapillary cells, and represents less than one percent of all vascular neoplasms. The most common site of involvement is the thigh followed by the retroperitoneum, while the paraspinal location is very rare. We report the first case of systemic "dumb-bell" haemangiopericytoma illustrated radiologically, which mimick, a dorsal "dumb-bell" neurinoma.

Child↗
PubMed1996

Alpha 1-antitrypsin activity in subarachnoid hemorrhage.

An altered equilibrium of protease/protease-inhibitor factors may be involved in the pathogenesis of aneurysm rupture: alpha 1-antitrypsin (alpha 1-AT) represents the most relevant inhibitor of elastase, a proteolytic enzyme enhancing catabolic processes of collagen metabolism. In the present study we test the hypothesis whether the activity of alpha 1-AT is altered in SAH patients; 5 cases with unruptured intracranial aneurysm and 27 patients with diagnosis of aneurysm SAH were included in the study. Blood samples were obtained immediately at admission. As control samples we consider the 5 cases of unruptured aneurysm, 15 cases of unruptured aortic aneurysms and 10 patients with non-vascular CNS diseases. Measurement of alpha 1-AT level was determined by immunoturbidimetric method. Serum levels of alpha 1-AT are significantly lower in patients admitted within 72 hours after SAH, if compared to patients admitted in a delayed phase. The linear relationship between alpha 1-AT and collagenase inhibitory percentage capacity (CIC) was shown to be different in the 4 subgroups considered, and so were the mean % CIC values in the between-groups comparison, except for unruptured aneurysm vs controls. The alpha 1-AT CIC in patients with SAH is shown to be the lowest when compared to controls and unruptured aneurysms (p = 0.0001).

Collagenases↗
PubMed1996

Spinal chondroma of the lumbar tract: case report.

BACKGROUND: Cartilage-forming tumors are benign cartilaginous tumors that rarely affect the spinal canal: they account for 2% of all spinal tumors and 2.6% of all benign bone tumors. Pathologically, they may be classified as chondromas, osteochondromas, chondroblastomas, and chondromyxoid fibromas. This oncotype may remain asymptomatic (it is confined within the vertebral structure) or may present as a hard paravertebral swelling (it invades the paravertebral structures) or more rarely, with a slowly-developing neurologic syndrome (it extends into the vertebral canal). METHODS: Thirty-one cases have been reported (including our case) of benign cartilage-forming tumors localized in the lumbar column. Only three cases of chondroma of the lumbar spine presented with lumbar radicular pain. We report a fourth case and review clinical and radiologic characteristics of these lesions. RESULTS: Eleven out of the 31 cases were diagnosed as chondromas, 17 as osteochondromas, while in three cases the histopathologic diagnosis was not reported. Seventeen cases originated from the neural arch, seven from the vertebral body, two from the spinous process, and in five cases the exact localization was not reported. This tumor is more frequent in males (21 cases out of 31), than in females (five cases); in five cases the sex was not reported. Mean duration of symptoms was 23 +/- 5.1 months (range: 1-96); chondromas have a short clinical history before diagnosis (13.8 +/- 3.4 months) compared to osteochondromas (28.6 +/- 7.6). Clinical presentation with local swelling is reported in 10 cases, in 10 cases local pain without radicular irradiation, in six cases lumbar pain with sciatica, in two cases signs and symptoms of cord compression, one case of cauda syndrome, while in four cases no clinical details are reported. Among the six cases presenting with sciatica, four were chondromas (in all cases the L4 level was involved), and one osteochondroma, while in one case the histopathologic diagnosis was not reported. CONCLUSION: Computed tomography is important and indispensable for preoperative diagnosis, giving a precise indication of tumor extent and location and its relationship to the adjacent structures; while MRI is helpful in detecting patterns related to histologic malignancy. It is important to examine the whole tumor histologically because it is known that there may be small areas that show signs of malignancy; thus is more likely in chondromas than osteochondromas.

Adult↗
PubMed1996

Abnormalities of collagen cross-linkage in posterior communicating artery aneurysms: a preliminary study.

The collagen of tissues submitted to mechanical load (i.e. arterial wall) is characterised by the presence of intermolecular covalent cross-links (hydroxylysyl pyridinoline or pyridinoline: PYD; and lysyl-pyridinoline or deoxypyridinoline: DPD) which stabilise the molecular structure. In this preliminary study we look for quantitative or qualitative alterations of collagen cross-linkage in intracranial aneurysms of posterior communicating artery (PCoA) which may be considered a site of elective weakening in the intracranial arterial circulation, being one of the most frequent locations of intracranial aneurysms and of so called "infundibular widening'. We analysed the collagen cross-linkage in 6 autopsy samples of intracranial arterial segments of the Circle of Willis which were removed from patients whose cause of death was other than cerebral hemorrhage, and in 6 samples of intracranial PCoA aneurysms obtained at surgery. The analysis of cross-links showed that there was no significant difference in collagen and cross-link content between autopic and aneurysmatic samples except for PCoA. In autoptic nonaneurysmatic samples of PCoA a lower content of PYD than in internal carotid artery (ICA) and a lower content of DPD than in all other arterial segments has been demonstrated; moreover a lower content of cross-links (DPD + PYD/ Collagen) was evident in nonaneurysmatic PCoA samples when compared to other segments (ICA and Anterior Communicating Artery). On the other hand, the mean content of DPD was significantly lower in PCoA aneurysms than in nonaneurysmatic samples of the artery and moreover, a significantly low content of cross-links (DPD + PYD/Collagen) is overemphasised in PCoA aneurysms, suggesting that the peculiar lower content of DPD in PCoA arteries may be considered the expression of minor resistance of the arterial wall at this site, and may be related to the higher incidence of aneurysms or infundibular widening of this arterial segment.

Adult↗
PubMed1995

Neurinoma of the trigeminal root and atypical trigeminal neuralgia: case report and review of the literature.

BACKGROUND: Neurinomas of the trigeminal nerve are a rare entity: those located in the posterior fossa account for 20% of all cases. In the majority of cases, the clinical presentation begins with fifth cranial nerve involvement producing a constant pain associated with other cranial nerve palsy and cerebellar signs. METHODS: We report the clinical features, neuroradiological imagings, and management of a case of trigeminal neurinoma located in the cerebellopontine angle, arising from the Vth cranial nerve root, presenting with an atypical trigeminal neuralgia; moreover, we analyze similar cases reported in the literature and we discuss whether pain can be produced by a neurinoma that arises central to the ganglion. RESULTS: The tumor presented with an atypical trigeminal neuralgia characterized by constant trigeminal pain with paroxystical burns, hyperesthesia and hyperactive autonomic dysfunction. Neuroradiological examinations provided the best preoperative localization of this lesion, allowing better planning of the surgical approach, considering the large size of this tumor. A retromastoid incision and posterior fossa craniectomy approach was used, with complete excision of the tumor. The paraxysmal sharp pain and hyperesthesia disappeared completely, but the constant burning pain persisted although it was less intense. At an 8-month follow-up examination, the patient showed a progressive improvement of clinical symptoms and control magnetic resonance imaging (MRI) showed the complete removal of the neoplasm and the absence of residuals or recurrences. CONCLUSION: Although in a high percentage of cases of atypical trigeminal neuralgia a neurovascular conflict might be suspected, the review of the present case suggests that the hypothesis of a trigeminal neurinoma must be investigated both with adequate neuroradiological procedures and/or microsurgical exploration of the trigeminal root.

Cranial Fossa, Posterior↗
PubMed1995

Oxidative events in neuronal and glial cell-enriched fractions of rat cerebral cortex.

The aim of this work was to investigate how neurons and glial cells separated from rat brain cortex respond to "in vitro" oxidative stress induced by incubation of the cellular fractions in the presence of prooxidant mixtures; in addition, the endogenous enzymatic antioxidant capacity of the purified fractions was investigated. Neuronal and glial cell-enriched fractions were obtained from rat cerebral cortex following passages of the tissue through meshes and centrifugations. The following parameters were evaluated: antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx), and glucose-6-phosphate dehydrogenase (G6PDH); lipid peroxidation products (TBARS) prior to (basal) and after (iron-stimulated) incubation with a mixture of iron and ascorbic acid; intracellular production of reactive oxygen species (ROS) using a fluorescent probe, dichlorofluorescin-diacetate, in basal, iron-stimulated, and menadione stimulated conditions. SOD and GSHPx activities showed no significant changes between neurons and glia, whereas CAT and G6PDH activities were found to be significantly lower in glia than in neurons. TBARS levels were significantly lower in the glial fraction than in neurons, both in basal and iron-stimulated conditions. ROS production showed no differences between neurons and glia in both basal and menadione-stimulated conditions. Iron-stimulation produced a marked increase in ROS production, limited to the neuronal fraction, with the glial values being similar to the basal ones. Our conclusion is that glia and neurons isolated from rat cerebral cortex show a similar pattern of the most important antioxidant enzymes and of their basal ROS production, whereas glia is more resistant in "oxidative stress" conditions.

Animals↗
PubMed1995

Prognostic value of the amount of post-traumatic subarachnoid haemorrhage in a six month follow up period.

Clinical and radiological patterns from 148 patients with post-traumatic subarachnoid haemorrhage (TSAH) were analysed with specific regard for the amount and distribution of blood in subarachnoid spaces to verify if these variables have any influence on overall outcome. The degree and extent of TSAH were classified according to Fisher's criteria: in 93 patients it was grade 1, in 36 grade 2, in 13 grade 3, and in six grade 4. There was a significant correlation between increasing clinical severity at admission and the amount of subarachnoid bleeding and a direct relation between a favourable outcome and a low Fisher grade. The distribution of subarachnoid blood was not significantly related to clinical condition at admission, whereas the pattern had a significant impact on the outcome. The results of the present study confirm that TSAH is a negative prognostic factor. Whereas the degree of TSAH is mainly related to clinical conditions at admission, the presence of subarachnoid blood clots both in basal cisterns and over the cerebral convexity indicates a poor outcome.

Adolescent↗
PubMed1995

Spinal epidural hematoma during anticoagulant therapy. A case report and review of the literature.

The authors present a case of spinal epidural hematoma during anticoagulant therapy. Clinical presentation is characterized by classic paravertebral back pain, followed by progressive neurological deficit due to spinal cord and radicular compression, with sensory deficits and bladder disturbance. From the literature, 37 cases are collected of spinal epidural hematoma during anticoagulant therapy, treated surgically. Pathogenesis, diagnosis, and differential diagnosis are discussed. Early surgical decompression of the spinal cord minimizes the degree of permanent neurological damage, because of the long-time compression of the spinal cord resulting in irreversible disturbance of circulation; therefore an early diagnosis is a better prognosis. The thoracic and cervical spine canal is smaller than the lumbar, therefore there is less space to reward the formation of hematomas, consequently the postoperative recovery is lower in patient with high spinal epidural hematomas with respect to lumbo-sacral spinal epidural hematomas; at this level the epidural hematoma may be insidious in its onset and tends to become chronic before definite treatment is undertaken.

Aged↗
PubMed1995

Anterior cervical discectomy: an analysis on clinical long-term results in 153 cases.

During the last three decades, the anterior approach to the cervical spine with interbody fusion has been increasingly preferred in the operative treatment of herniated cervical disc. Most studies on surgical procedure without interbody fusion are retrospective and reported that the bone graft is not important for the success of this technique. Between 1983 and 1993, 153 patients underwent surgery for the treatment of cervical degenerative disc disease: in 139 cases the technique without fusion was applied. This retrospective study analyze clinical and radiological parameters in order to verify any possible prognostic factor. 108 patients with radiculopathy and 31 patients with myelopathy were followed up clinically for at least 12 months up to 10 years. An excellent or good long-term result was achieved in 90.9% of patients with radiculopathy and 58.1% of those with myelopathy. The age of the patients, the duration of symptoms before diagnosis and the pathogenesis of disc herniation did not represent significant parameters influencing the outcome of patients. The results of the present study show that anterior discectomy without fusion lead to good clinical long-term results, either in patients with pure radicular syndrome, or in cases with myelopathy. The presentation with pure radicular signs is the most important factor in predicting a good overall outcome.

Adult↗
PubMed1994

Experimental subarachnoid hemorrhage: events related to anti-oxidant enzymatic systems and eicosanoid peroxide enhancement.

Experimental and clinical studies have emphasized the role of free radicals in the pathogenesis of vasospasm and neurological dysfunction after subarachnoid hemorrhage (SAH). Increases in both enzymatic (arachidonic acid cascade and eicosanoid peroxide production) and non-enzymatic (thiobarbituric acid reactive substances production) lipid peroxidation were found, pointing out the key role of arachidonic acid cascade in impairing membrane functionality in the post-hemorrhage brain. The aim of this work is to investigate whether a correlation exists between time-dependent modifications of eicosanoid peroxide production ("ex vivo" release of leukotriene C4 = LTC4) and antioxidant enzymatic systems in the brain after experimental subarachnoid hemorrhage in the rat. The release of the LTC4 is significantly enhanced at 1, 6 and 48 hours after SAH induction. Cu-Zn superoxide dismutase (SOD) activity is significantly reduced at 6 and 48 hours after SAH induction; Mn-SOD activity is significantly affected at 1, 6 and 48 hours after the hemorrhage. GSH-Px activity is significantly reduced only in the late phase (48 hours) after SAH. The linear regression of statistical analysis, performed to investigate any possible relationship among time-dependent modifications shows that the "ex vivo" release of LTC4 is significantly related to the decreasing trend of MnSOD activity (p < 0.001). The present results suggest that after SAH, a deficit in endogenous anti-oxidant defenses may play a role in making the brain more susceptible to lipid peroxidative events.

Animals↗
PubMed1994

Changes in non-synaptosomal and synaptosomal mitochondrial membrane-linked enzymatic activities after transient cerebral ischemia.

Non-synaptosomal and synaptosomal mitochondrial membrane-linked enzymatic activities, NADH-cytochrome c reductase rotenone insensitive (marker of the outer membrane) and cytochrome oxidase (marker of the inner membrane), were measured in rat brain hippocampus and striatum immediately after and 1, 4 and 7 days following the induction of complete transient ischemia (15 min) by the four vessel occlusion method. Furthermore citrate synthetase activity was measured with and without Triton X-100 in order to qualitatively evaluate the membrane permeability. Non-synaptosomal mitochondrial membranes showed reduction of both activities only in the late reperfusion phase: NADH-CCRRi decreased in striatal mitochondria after 4-7 days and only after 7 days in the hippocampus. COX activity decreased only in striatal mitochondria 7 days after ischemia. Non-synaptosomal mitochondrial membrane permeability did not show changes. Synaptosomal mitochondria showed a decrease of NADH-CCRRi only at 7 days of reperfusion both in hippocampus and striatum, while COX activity decreased only during ischemia and returned to normal levels in the following days in the two areas considered. In summary, free mitochondria showed insensitiveness to ischemia but they resulted damaged in the late reperfusion phase, while mitochondria from the synaptic terminal showed ischemic damage, partially restored during reperfusion. The striatal mitochondria showed a major susceptibility to ischemia/reperfusion damage, showing changes earlier than the hippocampal ones.

Animals↗
PubMed1994

Endothelin and aneurysmal subarachnoid haemorrhage: a study of subarachnoid cisternal cerebrospinal fluid.

Endothelin (ET) is considered one of the most potent vasoconstrictor polypeptides; several experimental studies have suggested its possible role in the pathogenesis of arterial vasospasm after subarachnoid haemorrhage (SAH). Previously reported data on plasma and CSF levels of endothelin in patients with a diagnosis of SAH have been controversial. Cisternal endothelin CSF levels and the possibility that they could be related to vasospasm and other clinical patterns of SAH were investigated. CSF samples were obtained from 55 patients admitted after angiographic diagnosis of intracranial aneurysm. Levels of ET-1 and ET-3 were measured through radio-immunoassay technique. Twelve patients who had operations for unruptured aneurysms were considered control cases; 43 patients with SAH were classified according to: Hunt and Hess grading at admission, vasospasm grading, CT classification and timing of surgery. In all 55 patients ET-1 was measured, while positive levels of ET-3 were found only in 17 cases of 48. No linear correlation was found between cisternal CSF ET-1 levels when considering time of surgery, CT classification, Hunt and Hess grading at admission, and vasospasm grading. The results of ET-3 assay should be considered with great caution because of the low percentage of positive cases. Cisternal CSF levels of ET-1 and ET-3 are not directly related to the occurrence of arterial vasospasm after the aneurysm rupture, or to other major clinical patterns of SAH; however, ET-1 expression occurs either in paraphysiological (unruptured aneurysm) or in pathological conditions (SAH). It is suggested that ET may potentiate, or may be potentiated by, other factors playing a consistent pathophysiological role in the development of vasospasm.

Brain Diseases↗
PubMed1994

Intracranial nail. A case report.

Penetrating cranio-cerebral trauma caused by fire-arm constitute the most frequent penetrating wounds in civilian ambit; in these cases the great extention of cerebral damage is the result of distructive forces generated by high velocity which moves this bodies. In civilian ambit cranio-cerebral wounds caused by penetrating bodies, but moved by low cinetic energy are increasing constantly, due to the development of industrial activities. The cases reported in literature are few; in the present paper we present the case of a cranio-cerebral wound caused by a nail, which is the longest nail ever reported in literature (9 cm). Cranio-cerebral penetrating wounds caused by nail are reported only as curious experience; none authors tried to standard the medical-surgical approach as for what concern the clinic valutation, as for treatment. We think that for these traumatic event, we can adapt the same valutations criteria used for wounds caused by fire-arms. For what concerns surgery of such injuries, we consider the emergency operation the best solution; generally in these cases the purpose of surgery is not the removal of devitalized tissues, evacuation of hematomas or removal of bone fragments or of penetrating bodies as happen in cases of penetrating bodies moved by high cinetic energy, but for the possible complications which can result immediately or after the trauma.

Accidents, Occupational↗
PubMed1993

Diffuse leptomeningeal melanomatosis of the spinal cord: a case report.

A rare case of diffuse leptomeningeal melanosis presenting with symptoms of spinal cord compression due to the presence of anterolateral arachnoid cyst and treated with Spetzler's drainage system is reported. The diagnosis of diffuse melanosis of the leptomeninges is rarely possible during life. In the present case MRI was of great help in the definition of the limits of the pathological process and the presence of the anterior compressing cyst. After laminectomy and a biopsy of the pathological tissue which achieved the histological diagnosis, an external drainage was inserted to reduce the cyst extension and to exclude the presence of melanocytes in the cystic fluid before a peritoneal shunt was placed. At 8th month of follow-up the patient is doing well with a dramatic reduction of symptoms and a significant reduction of spinal cord compression. The diagnostic role of MRI and the relationship between leptomeningeal melanosis and arachnoid cyst are discussed.

Adult↗
PubMed1993

Pharmacological characterization of the 5-hydroxytryptamine receptor coupled to adenylyl cyclase stimulation in human brain.

Recently, a 5-hydroxytryptamine (5-HT) receptor has been described, whose pharmacology was distinct from that of the already known serotonergic receptors, so that it has been called 5-HT4. Because the lack of a high affinity radioligand, the identification of this receptor depends entirely on functional pharmacological analysis. Its stimulation leads to an increase in cyclic AMP accumulation in mouse embryo colliculi neurons, in guinea pig hippocampus and in human heart. We studied the effect of two indoleamines, 5-HT and 5-methoxytryptamine (5-MeO-T), and a benzimidazolone derivative, BIMU 8, in stimulating basal adenylyl cyclase activity in human frontal cortex, and characterized the receptor subtype involved. In membranes prepared from this tissue, 5-HT, 5-MeO-T and BIMU 8 dose-dependently stimulated (13-25%) the basal enzyme activity (220 pmoles cyclic AMP/min/mg protein). 5-MeO-T behaved as a full agonist, BIMU 8 elicited about 60% of the maximal 5-HT effect. The selective 5-HT1A agonist 8-OH-DPAT, was devoid of any stimulating activity. ICS 205-930, a low affinity 5-HT4 receptor antagonist, completely reversed the effect of all three agonists at high concentrations. Therefore, the present data are consistent with the 5-HT-mediated stimulation of adenylyl cyclase in human frontal cortex resulting by the activation of a 5-HT4 receptor subtype.

5-Methoxytryptamine↗
PubMed1993

Antioxidant enzymatic activities after experimental subarachnoid hemorrhage in rats.

Lipid peroxidation has been hypotesized as one of possible factors involved in the pathogenesis of neuronal damage and delayed vasospasm after subarachnoid hemorrhage. In the brain there are anti-oxidant enzymatic systems which act as scavengers of superoxides and free radicals. In the present study the pattern of enzymatic anti-oxidant activities (Cu-Zn and Mn superoxide dismutase, and glutathione peroxidase) was investigated in an experimental model of subarachnoid hemorrhage in the rat in order to verify whether the hemorrhagic insult may be responsible for an impairment of such anti-oxidant systems. Enzymatic activities were assayed in three different rat brain areas (cerebral cortex, hippocampus and brain stem) of sham-operated and at 30 min, 1, 6 and 48 h after subarachnoid hemorrhage induction. After the hemorrhage induction the Cu-Zn superoxide dismutase activity in cerebral cortex was significantly reduced at all the set times (p < .05), while Mn-superoxide dismutase activity was significantly decreased since 1 h (p < .05) until 48 h (p < .05). Glutathione peroxidase activity was significantly reduced only in the late phase (48 h) of subarachnoid hemorrhage (p < .01). In the hippocampus, all enzymatic activities were significantly reduced in the late phase. In the brain stem Cu-Zn superoxide dismutase was significantly impaired at 1 and 6 h (p < .05) after subarachnoid hemorrhage induction, while in the late phase (48 h) reached the control value. The mitochondrial Mn-superoxide dismutase was significantly reduced since 1 h (p < .05) until 48 h (p < .02) after subarachnoid hemorrhage.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1992

Effect of high-dose methylprednisolone on anti-oxidant enzymes after experimental SAH.

Lipid peroxidation has been considered one of the most important factors involved in the pathogenesis of neuronal damage following subarachnoid hemorrhage. In the brain, the protective systems most involved against peroxidative and free radicals generated reactions are superoxide-dismutase (SOD) and glutathione-peroxidase (GSH-Px). Since these activities are subjected to a significant reduction following experimental SAH induction in rats, we investigated in the present study if the beneficial effect of high-dose methylprednisolone (MP) in inhibiting lipid peroxidative processes in SAH is possibly linked to an influence on anti-oxidant enzymatic activities. In brain cortex, after MP treatment, Cu-Zn SOD activity in the early phase and more dramatically in the late phase after SAH was restored (4.06 +/- 0.06 and 4.07 +/- 0.14 enzymatic units/mg of protein, respectively) if compared to hemorrhagic non-treated controls (3.69 +/- 0.16 and 2.96 +/- 0.06 enzymatic U/mg of protein) while Mn-SOD and GSH-Px activities were improved in treated animals only in the early and late phases after SAH, respectively. In the hippocampus, in treated rats Cu-Zn activity was partially restored only at 6 h, while Mn-SOD activity recovered at 48 h after SAH; no significant changes in GSH-Px activity were found in treated animals at any time. In the brain stem, in treated animals, Cu-Zn SOD activity was restored in the early phase (3.86 +/- 0.12 enzymatic U/mg of protein) up to control values of non-hemorrhagic rats (3.44 +/- 0.30 enzymatic U/mg of protein), while GSH-Px activity recovered in the late phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗