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Biomedical subjects

M Zuccarello

Publications and source records attributed to M Zuccarello.

At least 73 records · Page 4Linked to original sources
PubMed1989

Acute effect of the Nd:YAG laser on the cerebral arteriovenous malformation: a histological study.

The acute effect of Nd:YAG laser beam on cerebral arteriovenous malformations (AVMs) was examined. Histological examination of the specimens after treatment with the Nd:YAG laser revealed that the most prominent effect of the laser was shrinkage of the collagen of the vessels of the AVM, which led to laser-induced narrowing of blood vessels. The brain tissue confined to the resected AVM did not contain any histological evidence of acute damage. The resection of 10 cases of AVMs was safely accomplished with no morbidity or increased neurological deficits attributable to the laser technique.

Adolescent↗
PubMed1989

Effect of the 21-aminosteroid U-74006F on cerebral vasospasm following subarachnoid hemorrhage.

The purpose of this study was to use a new 21-aminosteroid (U-74006F) with in vitro antioxidant and antilipolytic properties as a pharmacological probe to assess the role of lipid hydrolysis and peroxidation in a rabbit model of subarachnoid hemorrhage (SAH)-induced vasospasm. Cerebral angiograms were performed on 15 rabbits. Eighteen hours later, 1 cc/kg of autologous blood was infused into the cisterna magna of all 15 animals. Six rabbits received no treatment, six received U-74006F starting 30 minutes after SAH, and three rabbits received the vehicle for U-74006F starting 30 minutes after SAH. At 72 hours post-SAH, a second angiogram was obtained. Digital subtraction angiographic techniques were used to measure the diameter of and contrast material flow through the basilar artery. At 72 hours post-SAH, vasospasm was evident in all untreated and vehicle-treated rabbits. The diameter of and the flow through the basilar artery were significantly reduced 42.3% +/- 6.6% and 46.8% +/- 5.8%, respectively, below pre-SAH levels (means +/- standard error of the means). Treatment with U-74006F eliminated the SAH-induced vasospasm; in treated animals, both the flow through and the diameter of the basilar arteries were at pre-SAH levels. These findings indicate that: 1) membrane lipid changes (that is, hydrolysis with eicosanoid production and/or peroxidation) contribute to the chronic vasospasm resulting from SAH, and 2) U-74006F prevents the SAH-induced chronic vasospasm in this model by limiting these pathological membrane events.

Animals↗
PubMed1988

Effect of intracisternal thromboxane A2 analogue on cerebral artery permeability.

Thromboxane, a highly vasoactive substance, is found in the cerebrospinal fluid of patients and experimental animals following subarachnoid haemorrhage. A stable synthetic analogue of thromboxane A2 was administered intracisternally in rabbits. This resulted in an increase in endothelial permeability of the major cerebral arteries to Evans Blue dye and horseradish peroxidase. Thromboxane may be involved in the pathogenesis of cerebral vasospasm and may be related to the contrast enhancement of the arteries in the basal cisterns on CT scans of patients who are prone to develop arterial narrowing.

Animals↗
PubMed1988

Morbidity and mortality of carotid endarterectomy under local anesthesia: a retrospective study.

It has been shown that carotid endarterectomy reduces the incidence of stroke in patients with symptomatic extracranial occlusive vascular disease in the absence of major perioperative complications such as stroke or death. We present a retrospective study of 106 carotid endarterectomies performed under local anesthesia in 100 patients in whom transient ischemic attack (TIA) or minor stroke had occurred. Nonfatal stroke occurred in 2%, and TIA occurred in 1%. There was no perioperative mortality. Our study suggests that, under local anesthesia, even high risk patients can be operated safely and the majority of carotid endarterectomies can be performed without the use of an indwelling shunt. Meticulous surgical technique is of great importance for achieving low perioperative complications.

Adult↗
PubMed1987

Immunohistochemical demonstration of alpha-1-proteinase inhibitor in brain tumors.

Using light microscopy and immunoperoxidase methods (PAP), the presence of alpha-1-proteinase inhibitor (API) was studied in seventeen brain tumors and four normal brain samples. The brain tumors included four glioblastomas, five low-grade gliomas, two metastatic lung carcinomas, two acoustic schwannomas, and four meningiomas. Normal brain displayed a finely granular intracytoplasmic staining confined to neuronal cells. Glial cells were negative for API. Fifteen of the 17 brain tumors were positive for API. Only two of five low-grade gliomas were negative for API. Glioblastoma and metastatic tumors exhibited the strongest positivity followed by acoustic neuroma, meningioma, and low-grade glioma. All positive samples exhibited finely granular intracytoplasmic API, and 50% exhibited extracellular API positivity. Metastatic and glioblastoma tumors demonstrated prominent extracellular API staining. Our results support the concept of a local production of API by brain tumors.

Blood Proteins↗
PubMed1987

Barrier disruption in the major cerebral arteries after experimental subarachnoid hemorrhage in spontaneously hypertensive and normotensive rats.

The effects of experimental subarachnoid hemorrhage (SAH) on the blood-arterial wall barrier in the major cerebral arteries were studied in 24 spontaneously hypertensive rats (SHR) and 13 Sprague-Dawley rats (SDR). Horseradish peroxidase (HRP) was given intravenously before killing the animals to assess the integrity of the barrier. In the acute experimental group, transient elevation of intracranial pressure (ICP) and systemic arterial pressure produced by cisternal injection of whole blood, saline solution, or Elliott's B solution resulted in extensive disturbance of the blood-arterial wall barrier. In the chronic group, only the cisternal injection of whole blood in SHR brought about an extensive and marked disturbance of the arterial permeability. These results suggest that: (a) early breakdown of the blood-arterial wall barrier seems to be due to a sudden rise in the ICP or arterial pressure; (b) in the chronic experiments, the subarachnoid clot is the most important factor responsible for the permeability changes; and (c) in the chronic SAH experiments, the blood-arterial wall barrier seems to be more vulnerable in SHR than in Sprague-Dawley rats. Due to the well-known similarities between SHRs and hypertensive human beings, patients with chronic hypertension should be considered at high risk after SAH for extensive blood-arterial wall barrier disturbances.

Animals↗
PubMed1987

Alpha-1-antitrypsin in human brain tumors.

This study was undertaken to confirm the presence of alpha-1-antitrypsin (alpha 1-AT) in human brain tumors and to attempt to elucidate its significance. Seventy-seven consecutive unselected patients with various brain tumors were entered in this study. The alpha 1-AT and alpha 2-macroglobulin contents of the tumor extracts were qualitatively assessed by Ouchterlony immunodiffusion techniques. Plasminogen activator (PA) activity was assayed electrophoretically on sodium dodecyl sulfate gels. The patients were were divided into two groups according to the positivity of their tumors to alpha 1-AT. Sixty-eight percent of the tumors were positive for alpha 1-AT, and all specimens were negative for alpha 2-macroglobulin. Clinical and biological parameters obtained in all study patients failed to show statistically significant differences between the two groups with the exception of PA activity (p = 0.001), the peritumoral edema as seen on computerized tomography, and the preoperative serum fibrinogen level. These three parameters were higher in the group with specimens positive to alpha 1-AT. This study supports the hypothesis that alpha 1-AT is produced primarily by tumor cells in proportion to the regional proteolytic and inflammatory activity, and may protect the tumor cells.

Brain Neoplasms↗
PubMed1986

Early outcome prediction in severe head injury: comparison between children and adults.

The prognostic value in 49 children and 56 adults of the following parameters recorded on admission was analyzed: oculocephalic and light reflexes, posturing, Glasgow Coma Scale (GCS), the need for ventilatory support, and the presence of associated injuries. All patients had been in coma for at least 6 h. The presence of intracranial hematoma and the duration of coma were recorded and the relative risk of poor outcome calculated. There was poor outcome in 51% of the children and 61% of the adults. Oculocephalic and light reflexes, posturing, GCS, need for ventilatory support, and duration of coma were significantly related to the outcome in children. Only oculocephalic and light reflexes, and posturing were significantly related to the outcome in adults. Some parameters appeared to have different prognostic value in children and in adults: the simultaneous evaluation of oculocephalic reflex and need for ventilation was the best prognostic guide in children, the light reflex was the best prognostic indicator in adults.

Adolescent↗
PubMed1986

Barrier disruption in the major cerebral arteries during the acute stage after experimental subarachnoid hemorrhage.

The effects of experimental subarachnoid hemorrhage (SAH) on the blood-arterial wall barrier in the basilar arteries were studied during the acute stage after SAH. SAH was induced in rats by injecting fresh autologous blood into the cisterna magna. Horseradish peroxidase (HRP) was given intravenously before killing the animals to assess the integrity of the barrier. In the basilar arteries taken from the animals that were killed 30 minutes after the cisternal injection of either mock cerebrospinal fluid or arterial blood, HRP reaction products were diffusely observed in the subendothelial spaces and smooth muscle layers. At 5 hours after the blood injection, no permeation of HRP into the subendothelial space was observed. Endothelial cell transcytosis seemed to be the important mechanism for HRP permeation into the subendothelial space rather than the opening of interendothelial junctions. The disruption of the blood-arterial wall barrier in the major cerebral arteries after SAH may be involved in the pathogenesis of vasospasm.

Animals↗
PubMed1986

Spontaneous cerebellar hematoma associated with chronic cerebellar stimulation. Case report.

A 24-year-old man developed a spontaneous cerebellar hematoma 5 years after the implantation of cerebellar electrodes. No vascular malformations were found either intraoperatively or radiographically. The histopathological findings of the cerebellar tissue obtained at biopsy from the region surrounding the electrodes support the hypothesis of a causal relationship between the spontaneous cerebellar hemorrhage and chronic cerebellar stimulation.

Adult↗
PubMed1985

Severe head injury in children: early prognosis and outcome.

The outcome is reported in 62 children with severe head injuries following a road traffic accident. All patients were comatose for at least 6 h; all patients were graded using the Glasgow Coma Score (GCS) or the Children Coma Score (CCS). Fifty-four patients were comatose immediately after injury, 8 after a lucid interval. Thirty patients had isolated head injuries and 32 had associated injuries, either long bone fractures or rupture of an abdominal organ. Additional information concerning main brainstem reflexes, posture and respiration was included in the study. The overall mortality was 32%. The goal of the study was to identify those clinical features available soon after injury which are important indicators of treatment and outcome.

Accidents, Traffic↗
PubMed1985

Is the auditory brain-stem response (ABR) effective in the assessment of post-traumatic coma?

The aim of the present study is to evaluate the capacity of ABRs to detect the limit between reversible dysfunction and irreversible damage to the brain-stem after severe head injuries. ABRs were recorded in 40 severely head-injured patients, strictly selected on the basis of clinical and CT scan findings and the absence of otologic disease. The interpeak latency of waves V-I (IPL V-I) was calculated and compared to that recorded in 19 healthy control subjects. The distribution curve for IPL V-I in surviving patients was analysed. The overall mortality was 47.5%; all the patients showing an IPL V-I greater than 4.48 msec died or remained vegetative, while all but 2 of the patients with IPL V-I less than 4.48 msec survived. The IPL V-I was significantly different from normal value in surviving patients, showing a brain-stem dysfunction in reversible post-traumatic coma. The 95% confidence limits for the mean IPL V-I in the surviving population were 4.08 and 4.24 msec. Our results confirm the high prognostic accuracy of ABR (P less than 0.001) and suggest the hypothesis that 95% of survivors have an IPL V-I ranging between 3.82 and 4.50 msec.

Adolescent↗
PubMed1985

Spontaneous intratumoral hemorrhage after ventriculoperitoneal shunting.

We report a 1 1/2-year-old child with an ependymoma in the posterior cranial fossa. As the computed tomographic scan showed evidence of marked triventricular hydrocephalus, the patient underwent ventriculoperitoneal shunting. Two hours after operation, he developed a fatal intratumoral hemorrhage. The indications and contraindications of ventricular external or internal drainage before posterior cranial fossa tumor removal are briefly discussed.

Brain Neoplasms↗
PubMed1985

Barrier disruption in the major cerebral arteries following experimental subarachnoid hemorrhage.

The effects of experimental subarachnoid hemorrhage (SAH) on the blood-arterial wall barrier in the major cerebral arteries were studied in 20 normotensive dogs. Horseradish peroxidase (HRP) was given intravenously before the animals were sacrificed to assess the integrity of the barrier. Transient elevation of intracranial pressure (ICP) produced by cisternal injection of saline solution resulted in HRP leakage at the branching points of the major cerebral arteries. Extensive disturbance of the blood-arterial wall barrier was consistently observed in the major cerebral arteries after SAH, with or without elevation of ICP. These results suggest that both subarachnoid clot and a sudden rise in the ICP are important factors causing the breakdown of the blood-arterial wall barrier, but that the effect of the clot is the most profound. Electron microscopy revealed that opening of the interendothelial junctions is one of the important mechanisms responsible for the HRP leakage in the major cerebral arteries following SAH. Disturbance of arterial permeability in the major cerebral arteries following SAH probably accounts for the abnormal post-contrast enhancement that occurs in patients who are prone to develop vasospasm following aneurysm rupture, and is probably involved in the pathogenesis of vasospasm.

Animals↗