Intramedullary astrocytoma with granular cell differentiation

Granular cell astrocytomas are uncommon tumors of the central nervous system (CNS) of which no cases have been documented in the spinal cord. This variant of glioma should not be confused with benign granular cell tumor which, although rare, has been well characterized in the spinal cord. We describe here the clinical, pathological, and radiological features of such an astrocytoma arising within the spinal cord at the dorsal level. A 48-year-old female was seen after about 1 year of dorsal pain and gradual spastic paraparesis. Magnetic resonance imaging (MRI) studies showed a 2-cm contrast-enhanced mass in the spinal cord at T6-T7, which had the appearance of an astrocytoma. At surgery, the tumor was found to be infiltrating a posterior column with no dural attachment. It was debulked and dissected. The histological diagnosis was astrocytoma with granular cell differentiation. In addition to documenting a unique example of intramedullary granular cell astrocytoma, we review the literature to investigate differences from other tumors with granular changes described in the spinal cord.

Oligodendroglial gliomatosis cerebri. Case report

Gliomatosis cerebri of oligodendroglial origin is very unusual. In the present article we illustrate a case of this pathology, outlining his severity and suggesting it seems to be more aggressive than the astroglial type. We give a short focus about the diagnosis and the therapy of this neoplastic disease.

Arnold's neuralgia caused by solitary fibrous tumor. Case report

Solitary fibrous tumor (SFT) is a mesenchymal tumor which has been identified in a wide variety of localizations, including soft tissues, peritoneum, retroperitoneum, mediastinum, upper respiratory tract, nasopharyngeal sinuses, periosteum and extremities, orbit, major body cavities, intraspinal and intracranial localizations. The authors describe a case of SFT found in the neck of a young patient suffering from Arnold's neuralgia. After surgery, diagnosis of SFT was based on characteristic histopathological findings, especially on immunohistochemical positive staining for CD34 antigen. It has been described also the characteristic patterns making this diagnose sure, focusing the point that cure is possible with complete excision of the lesion.

Meningeal melanocytoma of the temporal lobe. An uncommon tumor in an unusual location. Case report

Meningeal melanocytomas are rare pigmented tumors of the central nervous system. These tumors are benign melanotic lesions that derive from the melanocytes of the leptomeninges. They may occur anywhere in the cranial and spinal meninges; however, they are found prevalently in the posterior fossa and in the spinal cord. Their epidemiological features, natural history and response to treatment remain poorly understood, even if, in the last 2 years, some reviews have been published about it. We report a new case of intracranial supratentorial meningeal melanocytoma, in the temporal lobe, occurring in a 27-year-old man, admitted to our Institute with a long-time history of seizures. We report histological and radiological characteristics of our case, and briefly review the therapeutical options reported in literature. Preoperative neuroradiological finding is unclear; the preoperative diagnosis is usually meningioma, because of the long duration of symptomatology and the radiological appearance of the lesion as an extra-axial mass. Diagnosis of these lesions, as in our case, is made intraoperatively by the gross, jet-black appearance of the tumor and by histological examination. In spite of the benign biologic behaviour, the prognosis remains uncertain, because of the possible local recurrences. According to the results of some works of the last years, it seems appropriate to use postoperative radiotherapy for those patients with symptomatic residual, progressive or recurrent tumors not amenable to further resection.

Isolated cerebellar involvement in Rosai-Dorfman disease: case report

OBJECTIVE AND IMPORTANCE

Sinus histiocytosis or Rosai-Dorfman disease (RDD) is a rare but well-recognized disorder characterized by an unusual proliferation of histiocytic cells. Intracranial localization is a rare manifestation of RDD. Only three cases of localization in the posterior fossa have been reported in the literature. The present report describes the first case, to our knowledge, of cerebellar localization of RDD.

CLINICAL PRESENTATION

A 67-year-old woman was admitted to our institution with a 5-month history of cerebellar ataxia. Her medical history was unremarkable. The patient was alert and cooperative. No cranial nerve deficits were evident; Romberg positivity to the left side was recorded. No cutaneous abnormalities, lymphadenopathy, or hepatosplenomegaly were revealed by physical examination. Routine hematological and biochemical studies were normal except for the erythrocyte sedimentation rate, which was elevated. Radiologically, the lesion appeared as a well-defined and avascular mass in the right cerebellar lobe. Meningioma was considered the most likely diagnosis.

TECHNIQUE

The patient underwent a suboccipital craniotomy with complete excision of the lesion. Microscopic examination of the operative specimen revealed the presence of a mixed cellular population with predominant mature histiocytes. A peculiar feature was the presence of lymphocytes and monocytes within the cytoplasm of histiocytes (emperipolesis). Immunohistochemical study of the histiocytes revealed strong positivity for S-100, CD-68 antigen, and vimentin.

CONCLUSION

Involvement of the central nervous system in RDD appears to have a benign prognosis, especially in the absence of nodal diseases. Surgery is essential for diagnosis, and, when total removal is achieved, the outcome is generally good without risk of recurrence.

Collagenase-1 and stromelysin distribution in fresh human herniated intervertebral disc: a possible link to the in vivo inflammatory reactions

Chondrocytes may play an important role in the inflammatory reactions involving intervertebral discs: the role of metalloproteases (MMP) and the imbalance between proteases and their inhibitors seems to play a crucial role in the disc degenerative process. In the present study we have analysed the production of collagenase-1 and stromelysin in different parts of herniated intervertebral discs. Ten samples of herniated lumbar discs were obtained from adult patients operated on for primary microdiscectomy because of persistent radicular symptoms and subdivided into three samples: 1. The nearest to the nerve root in close contact with it, 2. the sample obtained from the intervertebral space, and 3. the sample obtained from the vertebral plates. The DNA content of each specimen was measured in order to obtain the best estimate of the cell content as well as to normalise the content of collagenase-1 and stromelysin found in the same tissues with respect to the number of cells. In 9 out of the 10 cases the DNA content was significantly higher in samples obtained from the intervertebral plates than in samples obtained near the nerve root or the intervertebral space. DNA content did not show any significant difference considering disc samples contiguous to the nerve root and samples obtained from the intervertebral space. The production of collagenase-1 did not show a specific pattern, being produced in similar quantities in the three disc compartments. The production of stromelysin was significantly lower in disc samples obtained from the intervertebral plates. In conclusion the results of the present study suggest firstly that in the herniated lumbar disc the reactivity and the production of pro-inflammatory agents is independent of DNA content, i.e. the cellularity of the sample, and secondly that activated cells in the intervertebral space and in the part of the disc in contact with the nerve root, even if scarce in number, are able to synthesise a proportionally higher quantity of MMP than the high-cellular disc fragments from the intervertebral plates, potentially playing a specific role in the inflammatory reactions.

Metalloproteases and intracranial vascular lesions

Recent studies have suggested that metalloproteinases (MMP) might be involved in the pathogenesis of cerebral aneurysm formation and rupture and that elevated serum levels of MMP may effectively be considered as possible markers of cerebrovascular malformations. The present study was planned in order to verify if serum levels of MMPs may be the mirror of the MMP activity in the wall of intracranial aneurysms, reflecting the predisposition to aneurysm development and/or rupture. A series of 84 patients operated for intracranial cerebrovascular lesions (63 aneurysms and 21 arterovenous malformations (AVM)) and 20 controls entered the study. Among the 63 cases of intracranial aneurysms, nine were discovered before rupture, while 54 patients were included after subarachnoid hemorrhage (SAH). Using radioimmunoassay, plasma elastase levels were measured in all cases, while in 25 cases, when aneurysmectomy was possible, the activity of elastase and collagenase were measured in aneurysm samples. Mean plasma elastase level in patients bearing both an intracranial aneurysm or an intracranial AVM was significantly higher than in controls, while there was no significant difference between plasmatic level of elastase in patients with aneurysms when compared with patients bearing an intracranial AVM; there was no significant difference between mean elastase level in patients who suffered SAH and patients bearing an intracranial unruptured aneurysm. The activity of elastase and collagenase measured in the aneurysm wall were significantly higher in cases of ruptured than in unruptured aneurysms. The present results show that plasmatic level of elastase does not reflect the activity of MMP as measured in the aneurysm wall and that the patterns of MMP activities measured in the aneurysm wall differ considerably at different stages of SAH. This suggests that local rather than systemic changes in metalloproteases activity might be involved in cerebral aneurysm formation and rupture.

Morphology of peri-implant regenerated bone, in sheep's tibia, by means of guided tissue regeneration

BACKGROUND

No data on the resistance to functional loads of bone regenerated by means of guided tissue regeneration, can be found. In this paper the new-formed bone is analyzed, in cases that see the surgical creation of defects in testing animals. The morphological aspects of perimplant bone, regenerated by means of bone substitutes or not, were evaluated.

METHODS

A coronal defect was created by means of a counter-sink bur. The following step provided for osseointegrated fixtures, with a machined or blasted (TiOblast) surface, to be installed. Some bone defects were filled with Bio-Oss, and covered with resorbable membrane (Vycril), others were left unfilled. The animals were sacrificed after different periods of time (24 and 45 days). Some thick sections (200 microns) underwent then microradiography and were examined with a microscope, under transmitted and polarized light. Other sections, thin (5 microns), were coloured with toluidine blue, Gomori's Stain and Solochrome Cyanine/Congo red.

RESULTS

Data confirm the excellent behaviour of bovine bone and of TiO blasted fixtures. The experimental results bring into evidence that, in cases of Guided Bone Regeneration (GBR) by means of membrane, the use of fixtures with a blasted surface (TiOblast), and of Bio-Oss as bone substitute, made osseointegration easier.

CONCLUSIONS

Results, moreover, suggest that in case of implant surgery with GBR, in order to allow the maturation of regenerated bone, it's healing time must be prolonged.

Oxidative stress in the human brain after subarachnoid hemorrhage

OBJECT

The aim of this study was to verify the patterns of antioxidant enzymatic activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the human brain after subarachnoid hemorrhage (SAH) to verify whether an "oxidative stress situation" characterizes the brain response to subarachnoid bleeding.

METHODS

Forty samples of gyrus rectus or temporal operculum that were obtained during a surgical approach to anterior circulation aneurysms were used for this study. The activity of total SOD, GSH-Px, and the SOD/GSH/Px ratio (which expresses the balance between the production of hydrogen peroxides by dismutation of superoxide radicals and the scavenging potential) were calculated in each case. Twelve samples were obtained from patients who underwent surgery for unruptured aneurysms (control group); 13 samples were obtained during surgical procedures performed within 72 hours of SAH; and 15 samples were obtained during delayed surgical procedures (> 10 days post-SAH). Ten patients presented with clinical deterioration caused by arterial vasospasm. In both SAH groups, the mean total SOD activity was significantly higher than in the control group (p=0.029). The mean activity of GSH-Px did not differ significantly between the SAH and control groups (p=0.731). There was a significant increase in the SOD/GSH-Px ratio in both SAH groups, as compared with controls (p < 0.05). There was a significant correlation between the enzymatic activity and the clinical severity of the hemorrhage, with findings of lower values of SOD and, mainly, of the SOD/GSH-Px ratio in the poor-grade patients. The SOD/GSH-Px ratio was 2.14+/-0.44 in patients who presented with clinical vasospasm and 1.24+/-0.2 in cases without vasospasm.

CONCLUSIONS

The results of this study show an imbalance of the antioxidant enzymatic activities in the human brain after SAH. which is linked to the severity of the initial bleeding and possibly modified by the development of arterial vasospasm.

Antioxidant status and alpha1-antiproteinase activity in subarachnoid hemorrhage patients

The antiproteasic activity of alpha1-antitrypsin (alpha1-AT) is reduced in cases of subarachnoid hemorrhage from ruptured intracranial aneurysm and particularly in patients currently smoking; alpha1-AT is very sensitive to oxidant agents. About 50% of physiological anti-oxidant systemic capacity is represented by Vitamin A, E and C. Plasmatic amounts of alpha1-AT, alpha1-AT Collagenase Inhibitory Capacity (CIC) and levels of vitamin A, vitamin E and vitamin C were analyzed in 39 patients, 26 women and 13 men, operated for intracranial aneurysm; 11 patients with unruptured intracranial aneurysm were considered as controls while 28 patients were included within 12 hours from subarachnoid hemorrhage (SAH). Plasmatic levels of vitamin A and vitamin E were significantly lower (p=0.038 and p=0.0158) in patients suffering SAH than in controls, while no statistically significant differences were found in mean plasmatic vitamin C levels. Level of alpha1-AT was not statistically different in controls and in patients with SAH; however, the activity of alpha1-AT, evaluated as CIC, is significantly reduced in patients with SAH (p=0.019). We have observed that systemic plasmatic levels of vitamins did not significantly differ in relation to smoking habit. Vitamin A and E represent an important defensive system against free radicals reactions. Particularly, vitamin E acts as an antioxidant by scavenging free-radicals. A reduced anti-oxidant status might be related to the higher sensibility of alpha1-AT to oxidative reactions and the activity of alpha1-AT is dependent on the antioxidant capacity of liposoluble vitamins. We can speculate that an acute systemic oxidative stress condition might influence the rupture of intracranial aneurysms.

Collagen cross-linkage, elastolytic and collagenolytic activities in cerebral aneurysms: a preliminary investigation

The pathogenesis of aneurysms formation and rupture is not clearly understood and is undoubtedly a multifactorial event. It is generally accepted that the aneurysm arises from an interaction between structural weakness of arterial wall and hemodynamic factors. Previous studies suggested the possible role of collagenolytic and elastolytic activities in aneurysm development, leading to extracellular matrix alteration. The content of collagen 3-hydroxypiridinium cross-links and elastase and collagenase activities were measured in 12 samples of intracranial aneurysms and in control specimens obtained from temporal superficial arteries and from autoptic samples of Willis Circle. Collagen content is significantly lower in aneurysm than in autoptic control samples (p < 0.01). The total amount of cross-links is significantly lower in ruptured aneurysms than in unruptured and autoptic controls (p < 0.01). Collagenase and elastase activities are significantly increased in ruptured cerebral aneurysms versus unruptured aneurysms (p < 0.01). Linear regression shows that an inverse relationship exists between cross-links content and both elastolytic (p = 0.0032) and collagenolytic (p < 0.001) activities in aneurysmal samples. Multiple regression shows that collagenase has a more important statistic impact (p = 0.027) than elastase (p = 0.08). The results of the study supports the hypothesis that an imbalance of protease-antiprotease homeostasis with elevated collagenolytic and elastolytic activities may represent the predisposing condition leading to aneurysms rupture through collagen depauperation and reduced cross-linkage of collagen fibres.

Antioxidant enzymatic activities and lipid peroxidation in cultured human chondrocytes from vertebral plate cartilage

In vitro models based on primary cultured human chondrocytes could be useful to study the ROS-mediated inflammatory processes that seem to involve chondrocytes in vivo. In this work, we studied the enzymatic antioxidative capability of human chondrocytes removed from vertebral plates during micro-discectomy and cultured 18 days, measuring total superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSHPx) activities. We also evaluated in the same cells the amount of malondialdehyde (MDA) in order to verify the effect of the variation of the cellular enzymatic antioxidative capability on the degree of membrane lipid peroxidation. Total SOD activity increased, even if not significantly, between the 12th and the 18th day. A significant variation of GSHPx (P<0.01) and of catalase (P<0.001) activity was observed between the 3rd and the 6th day with no further variation until the 18th day. A significant increase (P<0.001) of lipid peroxidation from the 3rd to the 18th day was also observed. These results seem to indicate that only fresh human cultured chondrocytes are suitable to study, through in vitro models, the in vivo behavior of the antioxidative status of these cells.

Spiral CT angiography and surgical correlations in the evaluation of intracranial aneurysms

We investigated the accuracy of spiral computed tomography angiography (CTA) in the detection and study of intracranial aneurysms by comparing CTA with selective angiograms and surgical findings. Twenty-six patients (9 men and 17 women; mean age 53.1 +/- 1.8 years) with suspected intracranial aneurysms were submitted to CTA (1- to 2-mm slices, pitch 1:1, 24 s, RI = 1) after a conventional CT examination showing subarachnoid hemorrhage (SAH) in 19 cases and during neuroradiological investigations performed for other reasons in 7 cases. One hundred twenty to 150 ml iodate contrast agent (0.3-0.4 gI/ml) were injected intravenously at 5 ml/s rate and with 12- to 25-s delay calculated with a preliminary test bolus. Three-dimensional shaded surface display (3D SSD) and maximum intensity projection (MIP) reconstructions were obtained from axial images. Then, within 48 h, all patients were submitted to digital subtraction angiography (DSA), with separate assessment of CTA and DSA findings. Twenty-two aneurysms shown by CTA were confirmed at DSA and surgery (true positives), whereas the vascular lesion was not confirmed at DSA in 2 cases (false positives). The presence of intracranial aneurysms was excluded at both CTA and subsequent DSA in 7 cases (true negatives) and there were no false negatives; sensitivity was 100 %, specificity 77.8 %, and diagnostic accuracy 93.5 %. Computed tomography angiography aneurysm location was confirmed at surgery in all cases, with very high accuracy in assessing the presence of an aneurysm neck (100 %). Computed tomography angiography accurately depicted the aneurysm shape in 20 of 22 cases, but failed to depict its multilobed nature in 2 cases. The mean aneurysm diameter calculated at CTA was 0.99 +/- 0.12 cm vs 1.09 +/- 0.11 cm at surgery (p < 0.01). The present results suggest that the high sensitivity of CTA, if confirmed by further studies, might help in avoiding having to resort to arteriography after negative CTA in SAH patients.

Cisternal CSF levels of cytokines after subarachnoid hemorrhage

Cytokines are considered as mediators of immune and inflammatory responses. Cisternal CSF levels of interleukin (IL)-6, IL-8, monocyte chemoattractant protein-1 (MCP-1) and of the soluble adhesion molecule E-selectin were evaluated in patients operated on for intracranial aneurysms. Cisternal CSF samples were obtained at surgery in 41 selected patients (31 with diagnosis of subarachnoid hemorrhage (SAH) and 10 control patients operated on for incidental unruptured aneurysms); 14 patients were operated within 72 h after SAH (early surgery) and 17 were operated after day 10 after the hemorrhage (delayed surgery). The CSF levels of cytokines were evaluated using radioimmunoassay and their concentrations were related to the timing of surgery, the amount of cisternal subarachnoid blood clots and the onset of clinical and angiographical evidence of arterial vasospasm. Mean cisternal CSF levels of IL-6, IL-8 and AMCP-1 are significantly higher in samples obtained from patients early operated after SAH, while levels of E-selectin were below the threshold value of the method in all 41 cases. In the early operated group 7 patients presented symptomatic vasospasm: levels of IL-8 and MCP-1 were not significantly different were compared to those of uncomplicated cases; on the other hand, significantly higher levels of IL-6 were shown in the subgroup of patients operated within 72 h after SAH and developing vasospasm. Among the patients undergoing delayed surgery 5 presented symptomatic vasospasm, but no significant difference was shown in cisternal CSF levels of cytokines measured. The results of the present study show that in patients with unruptured aneurysms cytokines are present in cisternal CSF in scarce quantities and that in subarachnoid spaces after SAH there is an impressive increase of IL-6, IL-8 and MCP-1. Moreover, the higher cisternal CSF levels of IL-6 found in the early stage after SAH might have a predictive value regarding the occurrence of symptomatic vasospasm.

A cost-effectiveness analysis on different surgical strategies for intracranial aneurysms

BACKGROUND

Economical studies on surgery of intracranial aneurysms have considered only the significant benefit of surgical approach on unruptured aneurysms and no studies have been performed comparing cost/benefit analysis of early vs delayed surgery. The present study was retrospectively performed in order to verify whether different treatment options in aneurysm surgery have a different cost/benefit ratio.

METHODS

We have analysed a series of 137 patients which underwent surgery for intracranial aneurysms (21 unruptured aneurysms, 56 early surgery and 60 delayed surgery). In the analysis we assumed that each state of an operated patient has an assigned quality of life value and an associated medical cost. We expressed the outcome of each patient as the expected length of survival adjusted for quality, and referred to it as "quality-adjusted life years" (QALY). We considered for each patient the direct cost of Hospitalisation (obtained from DRG reimbursement), the Rehabilitation cost and the correction due to QALY adjusted for age and deficit.

RESULTS

Significantly higher costs are reported in patients which present as major complication the hydrocephalus and which are treated with nimodipine; moreover, the costs for patients operated for unruptured aneurysms is significantly lower than that of patients which presented with SAH. Meanwhile, the average QALY adjusted for post-operative neurological deficit at three months follow-up is higher in patients operated for unruptured aneurysms than in patients operated after SAH. The cost-effectiveness of different treatment strategies did not significantly differ considering age and neurological deficit adjustment; thus, after SAH, the choice of early or delayed surgery may depend on clinical and logistic conditions related to the neurosurgical department and its organisation, because there is no significant economical advantage leading to recommend early versus delayed surgery.

CONCLUSIONS

In conclusion the present data suggest that a decreased length of hospitalisation and a decreased cost for treatment of unruptured aneurysms should justify a more rigorous preventive screening with available non invasive neuroimaging techniques.

Superoxide dismutase activity in cisternal cerebrospinal fluid after aneurysmal subarachnoid haemorrhage

It has been recognised that the level of superoxide dismutase (SOD) significantly increases in CSF as the result of cerebral ischaemic damage. The aim of this study was to correlate the CSF levels of SOD enzymatic activity to the patterns of subarachnoid haemorrhage with regards to ischaemic complications due to vasospasm. A series of 78 patients operated on for intracranial aneurysms was studied; all patients were monitored with serial TCD measurements every second day after SAH. CSF samples were obtained at surgery by cisternal puncture of the subarachnoid cistern nearest to the aneurysm. SOD activity was assayed spectrophotometrically. Mean cisternal CSF level of SOD in 12 control cases (12.99 +/- 2.33 U/ml) is significantly higher (p < 0.01) than in 26 patients operated on between day 1 and 3 from last SAH episode (4.44 +/- 0.7 U/ml) and in 40 patients treated by delayed surgery (7.64 +/- 0.92 U/ml). In 13 patients presenting neurological deterioration related to arterial vasospasm mean cisternal SOD level was 12.23 +/- 1.86 U/ml; in 27 cases without vasospasm mean level was 5.43 +/- 0.7 U/ml (p < 001). The present results suggest that (a) cisternal CSF levels of SOD significantly decreases after SAH, probably in relation to an impaired synthesis in the brain compartment and that (b) a substantial elevation of SOD levels is evident in patients suffering ischaemic complications vasospasm-related. Biochemical events in the brain compartment could influence the expression and release of anti-oxidant enzymes in CSF after SAH.

[Osteo-conductive materials: animal experiments and instrumental analysis II]

BACKGROUND

In daily dental surgery practice, when it is not possible to obtain-enough autogenous bone graft to fill bone defects, bone substitutes can be useful for bone regeneration.

MATERIALS AND METHODS

After a preliminary microscopic examination of histologic samples obtained from semithin sections of the tibias of rats showing no major differences in the results both for the single material and implant time, further studies on five different osteoconductive materials used in oral clinical practice were carried out with microradiography, SEM and X-ray microanalysis. In experimental animals (rats) bone defects 3 mm large were surgically induced in both tibias: one of the defects was filled by bone substitutes and on the other side the bone defect healed naturally.

RESULTS AND CONCLUSIONS

The findings obtained were studied in depth, and allowed to conclude that the materials tested are suitable for the purpose for which they are marketed. Non-demineralized bovine bone showed the best results with a high degree of osteointegration. However, the results also show that not all the materials tested offer healing advantages over controls.

Deficiency of total collagen content and of deoxypyridinoline in intracranial aneurysm walls

The tissue contents of total collagen and of 3-hydroxypyridinium cross-links, pyridinoline (PYD) and deoxypyridinoline (DPD), were measured in 15 samples of human aneurysms of Willis' Circle obtained at surgery and in 25 autopsy control samples of intracranial arteries of Willis' Circle obtained from 6 subjects who died of other causes than cerebral hemorrhage. PYD and DPD were detected fluorimetrically after HPLC separation. Total collagen content was significantly lower (P < 0.001) in aneurysm samples (mean +/- S.E.M. 2.50 +/- 0.33 nmol of alpha 1(I) collagen chain per mg of delipidated and dried material) than in controls (mean +/- S.E.M. 3.86 +/- 0.14). DPD, but not PYD, content appears to be lower in aneurysm walls. In the aneurysms, the tissue contents of PYD ranged from 212 to 587 pmol/nmol of alpha 1(I) collagen chain (mean +/- S.E.M. 430 +/- 31) while in control samples the values observed ranged from 292 to 642 (mean +/- S.E.M. 471 +/- 21). The tissue content of DPD was measurable only in 6 aneurysm samples (60%), ranging from 12 to 60 pmol/nmol of alpha 1(I) collagen chain (mean +/- S.E.M. 33 +/- 9), while in control samples, DPD content ranged from 30 to 123 (mean +/- S.E.M. 75 +/- 5).

Platelet derived growth factor and subarachnoid haemorrhage: a study on cisternal cerebrospinal fluid

Platelet derived growth factor (PDGF) was identified as a powerful mitogenic growth factor which is released from activated platelets and has a marked activity as vasoconstrictor agent. In the present study we have measured cisternal cerebrospinal fluid (CSF) levels of PDGF in 72 patients operated on for intracranial aneurysm in order to verify whether it might be related to the clinical aspects of SAH with special regard to symptomatic vasospasm. CSF samples were obtained at surgery by cisternal puncture of the subarachnoid cistern the nearest to the aneurysm before aneurysm isolation and exclusion. The specimen were frozen in liquid nitrogen and stored at -80 degrees C until analysis. PDGF was measured using a commercially available reagent. Values are expressed as pg/ml of CSF. In 18 cases no radiological and clinical signs of SAH were detected and the mean cisternal CSF level of PDGF was 885.0 +/- 104.5 pg/ml; 20 patients were operated on between day 1 and 3 from the last SAH episode: mean cisternal CSF level of PDGF was 1917.5 +/- 459.4 pg/ml. In 34 patients treated with delayed surgery protocol, mean cisternal CSF level of PDGF was 995.3 +/- 73.8 pg/ml. Statistical analysis showed significant differences between groups (P: 0.011). In the subgroup of patients operated on within day 3 after SAH, 6 presented vasospasm and had mean cisternal CSF PDGF level which was significantly higher (P < 0.01) than in 14 patients without vasospasm. In the delayed "surgical" patients there was no significant difference in cisternal CSF levels of PDGF considering the occurrence of vasospasm. The results of the present study suggest that (a) after SAH there is a significant release of PDGF early after SAH and (b) higher levels of PDGF found in cisternal CSF of patients operated on within 72 hours after SAH may be predictive of symptomatic vasospasm.

Synaptosomal iron-dependent lipid peroxidation inhibition after subarachnoid hemorrhage by lazaroid in vivo treatment

The production of oxygen-free radicals and their subsequent peroxidative action on membrane unsaturated fatty acids could be enhanced after subarachnoid hemorrhage (SAH). We have studied the effects of the in vivo pharmacological treatment with a lazaroid (U78517F) after experimental SAH, on lipid peroxidative patterns in cortical synaptosomal preparations. U78517F is a lipid-soluble antioxidant with a potent action to inhibit iron-dependent lipid peroxidation. Experimental SAH was induced in anesthetized rats by slow injection of 0.3 mL of autologous arterial blood into cisterna magna. The hemorrhagic animals were treated with 5 mg/kg iv of U78517F immediately after surgical operation. The animals were sacrificed 1 d after the hemorrhage and the thiobarbituric acid reactive material (TBAR) was assayed in basal conditions and after 1, 3, 5, 10, and 20 min of incubation at 37 degrees C with a pro-oxidant mixture on three different rat groups: sham-operated (0.3 mL of mock cerebrospinal fluid (CSF) into cisterna magna), hemorrhagic (0.3 mL of autologous arterial blood into cisterna magna), and hemorrhagic-treated. The hemorrhagic event did not influence the membrane lipoperoxidation levels in basal conditions, whereas peroxidative stimulation in vitro caused significant increases in hemorrhagic animals compared to the sham-operated, and in hemorrhagic-treated animals, the synaptosomal TBARs were similar to controls. The pharmacological treatment showed its effectiveness only following incubations with pro-oxidants; therefore, U78517F seems to be protective for membranes in case of severe lipid peroxidative stress.

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.

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.

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).

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.

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.

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.

Ganglioneuroblastoma of the spinal cord

We report a case of ganglioneuroblastoma of the spinal cord in a 42-year-old man. MR examination was nonspecific, and the diagnosis was made from histologic findings. The MR picture was that of an intramedullary, mainly solid tumor with a central necrotic or cystic portion. The clinical picture and course were also nonspecific.

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.

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.

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.

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.

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)

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.

Ex vivo release of eicosanoids after aneurysmal subarachnoid hemorrhage: a preliminary experience in humans

Authors addressed the question whether the byosynthesis and the release of specific eicosanoids may occur in human brain cortex, and if the qualitative pattern of arachidonic acid metabolism is similar to that observed in experimental SAH. Human brain samples from 18 patients operated on for anterior communicating artery aneurysm (5 unruptured aneurysms considered as control cases, 7 patients operated on between Days 1 and 4 after SAH and 6 patients operated on between Days 10 and 14) were studied for the ex vivo release of 4 selected eicosanoids (Prostaglandin D2, E2, 6-keto-PGF1a and Leukotriene C4). Levels of arachidonate metabolites were determined by radioimmunoassay technique. PGD2 release is significantly lower in cases operated on delayed phase if compared to both control cases (p less than 0.05) and patients operated on in the acute phase, while there is no significant difference between the release of PGD2 in control cases and patients operated on in the acute phase. Release of 6-keto-PGF1a is significantly higher in patients operated on in a delayed phase (p less than 0.03 vs patients operated on in the acute phase and p less than 0.05 versus control cases). The release of LTC4 is significantly enhanced (p less than 0.05) in cases operated on in the acute phase if compared with unruptured aneurysms. The release of PGE2 is significantly enhanced in patients operated on in the acute phase (p less than 0.05) if compared to patients with unruptured aneurysm.(ABSTRACT TRUNCATED AT 250 WORDS)

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)

Primary solitary intracranial melanoma: case report and review of the literature

Among CNS tumors, intracranial melanomas represent a subject of interest for neurooncologists and neurosurgeons because clinical and radiological patterns of these tumors can mimic the presence of meningiomas, and in spite of their malignant behavior they can be satisfactorily treated. In the present report we describe a new case of primary intracranial melanoma that displayed some radiological features of meningioma; we review the clinical features of 80 previously well-documented cases. The importance of neuroradiological and histochemical (S-100 protein, antimelanin antibodies, proliferating cell nuclear antigen staining) methods and of flow cytometry in helping with histopathological examination is stressed. Review of the clinical histories demonstrates that surgical excision is recommended in most cases, depending on tumor location, and that if total removal is performed, long-term disease-free periods can be attained.

Effects of nicardipine treatment on Na(+)-K+ ATPase and lipid peroxidation after experimental subarachnoid haemorrhage

The calcium theory of neuronal damage has been recently adapted to subarachnoid haemorrhage (SAH). It is proposed that haemorrhagic insult to the brain causes free radical-mediated destructive reactions of membrane phospholipids, and the consequent decrease of phospholipid-dependent enzymatic activities, such as Na(+)-K+ ATPase. In the present study we have studied the effects of Nicardipine treatment on lipid peroxidation and Na(+)-K+ ATPase activity after experimental induction of SAH. SAH was induced in anaesthesized rats by slow injection of 0.3 ml of autologous arterial blood into the cisterna magna. We assessed the extent of lipid peroxidation by measuring the level of thiobarbituric acid reactive substances (TBARS) and Na(+)-K+ ATPase activity in 3 different rat brain areas (cerebral cortex, hippocampus and brain stem) of sham-operated (0.3 ml of mock CSF into cisterna magna) and at 1 hour, 6 hours and 48 hours after SAH induction; simultaneously, we investigated the capacity of cerebral lipid peroxidation by measuring the accumulation of TBRAS in homogenates of brain areas incubated under aerobic conditions. Na(+)-K+ ATPase activity decreased in the cerebral cortex at 1 hour and 6 hours and in brain stem at 1 hour after SAH, while the same enzymatic activity did not change in the hippocampus. There was no significant difference in lipid peroxide content between sham-operated and haemorrhagic animals; Nicardipine treatment reduced the TBRAS content and induced the recovery of Na(+)-K+ ATPase activity, exerting a brain protective role against the detrimental effects of the haemorrhage.

[High resolution tridimensional study of the blood vessels of the neck and the intracranial circulation with magnetic resonance angiography]

Magnetic Resonance Angiography (MRA) is a modern vascular imaging technique which allows the noninvasive and direct imaging of vessels. The authors aimed at evaluating the diagnostic accuracy of MRA in the study of pathologic conditions in the neck and intracranial vessels; spatial resolution of the technique was also investigated. Twenty-four healthy volunteers and 82 patients suffering from various diseases of the head and neck vessels were included in the study. First of all, MRA capabilities were investigated in visualizing normal vessels of both neck and intracranial circle. The diagnostic accuracy of the method was then evaluated in the study of vascular diseases, and the results compared with conventional/digital angiographic findings. The comparison demonstrated how stenoses and atherosclerotic plaques tend to be overestimated by MRA because of technical artifacts inherent to the technique itself, whereas vascular ulcerations and aneurysms are frequently underestimated. However, this data was steady and therefore evaluable--the exact knowledge of the artifacts making diagnosis reliable. The diagnostic and technical problems relative to the various vascular diseases are discussed. Finally, several hypotheses of diagnostic iter are suggested.

"Ex vivo" release of eicosanoid from human brain tissue: its relevance in the development of brain edema

The specific mechanism underlying the genesis of vasogenic brain edema is still debated: the role of arachidonic acid is considered extremely important, as it is a possible activator of self-maintaining reactions enhancing the release of vasoactive and cytotoxic compounds. The relationship between arachidonic acid metabolism and brain edema has been studied primarily in brain tissue samples or in the extracellular fluid, whereas the residual capacity of perilesional tissue to synthesize and release eicosanoids has not been investigated. In the present study, perilesional samples of brain tissue were available from 4 patients operated on for brain metastasis, from 8 patients who had malignant neuroepithelial tumors, from 4 with meningiomas, and from 5 with subarachnoid hemorrhage. A brain edema index was calculated from the preoperative computed tomographic scan. The "ex vivo" method allowed determination of the residual capacity of endogenous arachidonic acid metabolism. The edema index is significantly higher in patients with brain metastasis (6.5 +/- 0.8) and neuroepithelial tumors (3.6 +/- 0.2) than in those with meningiomas (1.5 +/- 0.06), subarachnoid hemorrhage (1.7 +/- 0.18), and in controls. In patients with metastatic and neuroepithelial tumors there is a significant correlation between peritumoral brain edema and the capacity to synthesize leukotriene C4 (P less than 0.05); the capacity to synthesize leukotriene C4 is also significantly elevated after subarachnoid hemorrhage (13.91 +/- 2.6 ng/ml of incubation medium) when compared with control cases (5.56 +/- 0.91). The capacity to synthesize prostacyclin is significantly higher in patients with brain metastasis than in those with neuroepithelial tumors and meningiomas (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of high-dose methylprednisolone and U74006F on eicosanoid synthesis after subarachnoid hemorrhage in rats

Free radicals and lipid peroxidation of membrane fatty acids are thought to play a role in the pathogenesis of arterial vasospasm and the physiopathologic patterns of neuronal damage after subarachnoid hemorrhage. We have evaluated the effects of treatment with either high-dose methylprednisolone every 8 hours or a single dose of U74006F on the temporal profile of ex vivo synthesis of four selected eicosanoids in brain slices after experimental induction of subarachnoid hemorrhage in rats. Prostaglandins D2 and E2, prostacyclin and leukotriene C4 levels were determined by radioimmunoassay after 1-hour incubation of the brain slices. The synthesis of prostaglandin D2 and 6-ketoprostaglandin F1 alpha at 48 hours after subarachnoid hemorrhage was significantly higher when compared to sham-operated animals (p = 0.01); prostaglandin E2 release was significantly enhanced at 6 hours after subarachnoid hemorrhage (p = 0.01). The release of the lipoxygenase metabolite was significantly enhanced at 1, 6, and 48 hours after subarachnoid hemorrhage induction. Both treatment regimens significantly reduced the ex vivo synthesis of prostaglandin D2, prostaglandin E2, and leukotriene C4 at 1, 6, and 48 hours after subarachnoid hemorrhage, whereas the effects on 6-ketoprostaglandin F1 alpha synthesis differed in the two treatment groups. U74006F enhanced the synthesis of prostacyclin metabolite in the early phase after subarachnoid hemorrhage, and high-dose methylprednisolone reduced the increasing synthesis at 48 hours. A strict comparison between the two treatments was not possible because of the different modalities of administration. However, these data suggest that the antioxidant effect of single-dose treatment with U74006F influenced the early and delayed effects on enzymatic lipid peroxidation, whereas the effects of methylprednisolone administration every 8 hours were more significant in the delayed phase.

Experimental isobaric subarachnoid hemorrhage: regional mitochondrial function during the acute and late phase

Patients treated for aneurysmal subarachnoid hemorrhage show, in the long-term follow up, an elevated rate of cognitive disturbances that are mainly related to the impact of the initial bleeding: the neurotoxic effects of blood deposition in subarachnoidal spaces may result in a diffuse encephalopathy, but the intrinsic mechanism and the biochemical correlates are not known. In the present study we have evaluated mitochondrial function after experimental induction of subarachnoid hemorrhage. Mitochondrial function was evaluated in four different rat brain areas (frontal cortex, occipital cortex, hippocampus, and brain stem) after experimental isobaric subarachnoid hemorrhage in rats. Subarachnoid hemorrhage was induced by injecting 0.07 mL of arterial autologous blood into the cisterna magna. Intracranial pressure did not significantly increase. The nonsynaptic mitochondrial fraction was isolated from different rat brain areas, and the maximal rate of enzymatic reactions of some key enzymatic activities related to the Krebs cycle [nicotinamide adenine dinucleotide (oxidized form) (NAD+)-isocitrate dehydrogenase, citrate synthase, and succinate dehydrogenase] and of the electron transfer chain (cytochrome oxidase) were evaluated. The nonsynaptic mitochondrial fraction was utilized also to check parameters related to the mitochondrial respiration: state 3, state 4, uncoupled state, respiratory control ratio, and adenosine 5'-diphosphate/oxygen ratio. The biochemical parameters were measured at 1 and 72 hours after the subarachnoidal injection of blood. Subarachnoid hemorrhage did not affect the mitochondrial enzymatic activities both at 1 and 72 hours, while the mitochondrial enzymatic activities parameters were significantly affected: in particular, a significant decrease of respiratory control ratio in all tested brain areas was demonstrated. The increased mitochondrial vulnerability in the delayed phases could be one of the biochemical correlates of post-hemorrhagic encephalopathy.

Effects of high-dose methylprednisolone on Na(+)-K+ ATPase and lipid peroxidation after experimental subarachnoid hemorrhage

The production of oxygen-free radicals and their subsequent peroxidative action on membrane unsaturated fatty acids could be enhanced after subarachnoid hemorrhage. High-dose methylprednisolone (30 mg/Kg i.v.) treatment can antagonize acute SAH-induced brain hypoperfusion and protect the ultrastructural integrity of endothelial cell membranes. Experimental subarachnoid hemorrhage (SAH) was induced in anesthesized rats by slow injection of 0.3 ml of autologous arterial blood into cisterna magna. Tissue lipid peroxidation, quantified as thiobarbituric acid reactive material (TBAR) and Na(+)-K+ ATPase activity were assayed in three different rat brain areas (cerebral cortex, hippocampus and brain stem) of controls (without any surgical manipulation), sham-operated (0.3 ml. of mock CSF into cisterna magna) and after SAH induction, at 1 h, 6 h and 48 h. Na(+)-K+ ATPase activity decreased in the cerebral cortex at 1 h and 6 h and in brain stem at 1 h after SAH, while the same enzymatic activity was unchanged in the hippocampus. High-dose methyl-prednisolone treatment (started immediately after SAH induction) enhanced the Na(+)-K+ ATPase activity until control levels. There was no significant difference in lipid peroxide content between sham-operated and hemorrhagic animals; however, the injection itself induces a transient increase of TBAR (1 h after injection) and methylprednisolone treatment decreases the products of lipid peroxidation in all brain areas.

High-dose methylprednisolone and 'ex vivo' release of eicosanoids after experimental subarachnoid haemorrhage

In the present study we have investigated the effects of high-dose methylprednisolone (MP) treatment on the 'ex vivo' release of four major eicosanoids in an experimental model of subarachnoid haemorrhage (SAH) with the aim of verifying: (a) the efficacy in reducing arachidonic acid metabolism enhancement; (b) whether high-dose methylprednisolone is effective on both the cyclooxygenase and lipoxygenase pathways; and (c) discussing the possible role of high-dose MP treatment in brain protection after SAH. Levels of prostaglandin D2 and E2, prostacyclin and also leukotriene C4 were determined by the radioimmunoassay technique after 1 h incubation of cerebral cortex samples of rats which had been subjected to experimental SAH procedure (injection of 0.3 ml of autologous arterial blood). The release of prostaglandin D2 at 48 h after SAH is significantly higher when compared to that of sham-operated animals (P less than 0.01); prostaglandin E2 release is significantly enhanced at 6 h after the SAH procedure (P less than 0.01); release of the lipoxygenase metabolite is significantly enhanced at 1, 6 and 48 h after SAH induction; MP significantly decreases the release of all eicosanoids, and values in treated animals do not differ from those of sham-operated animals. The results of the present study suggest that the global inhibitory effect of high-dose MP treatment on the 'ex vivo' release of eicosanoids after experimental SAH could be considered to be one of the neurochemical correlates for the reduced incidence and severity of arterial inflammatory response, which results in chronic vasospasm and supports the clinical evidence of MP efficacy in preventing or reducing the incidence of arterial vasospasm after aneurysmal rupture.

[Gingival hypertrophy induced by cyclosporin A in heart transplant patients]

The clinical and histological aspects of gingival hypertrophy due to cyclosporine-A in 10 heart-transplanted patients are studied. The behaviour to avoid or to limit gingival overgrowth is suggested.

Arachidonic acid metabolism and pathophysiologic aspects of subarachnoid hemorrhage in rats

We studied the ex vivo production of prostaglandin D2, prostaglandin E2, 6-ketoprostaglandin F1 alpha, and leukotriene C4 in the brain tissue of rats subjected to experimental subarachnoid hemorrhage. The ex vivo method allows the study of arachidonic acid metabolites released from brain slices at different times after subarachnoid hemorrhage induction and reflects the residual capacity for arachidonic acid metabolism after the pathologic event. The rats were sacrificed 30 minutes, 1 and 6 hours, and 2 days after subarachnoid hemorrhage was induced by the injection of 0.30 ml autologous arterial blood into the cisterna magna. Concentration of prostaglandin D2 and 6-ketoprostaglandin F1 alpha was increased significantly relative to control 2 days after induction. The concentration of prostaglandin E2 was increased significantly 6 hours after induction, while ex vivo production of leukotriene C4 was increased significantly at 1 and 6 hours and 2 days. The correlation between these results and the occurrence of vasospasm after subarachnoid hemorrhage is discussed. The results obtained from the ex vivo incubation of brain tissue slices after experimental subarachnoid hemorrhage suggest that after the hemorrhage there is a significant modification of brain eicosanoid metabolism, which could be of great importance in interpreting the pathogenesis of subarachnoid hemorrhage-related neuronal impairment.

Effects of nicardipine on the ex vivo release of eicosanoids after experimental subarachnoid hemorrhage

The activation of lipid peroxidation and the enhancement of arachidonic acid metabolism have been demonstrated as indicators of brain damage after subarachnoid hemorrhage (SAH). Meanwhile, the final common pathway of neuronal damage seems to be related to the impaired homeostasis of Ca++. The present study evaluated the effect of the calcium-antagonist nicardipine on arachidonate metabolism after experimental induction of SAH. The ex vivo release of four eicosanoids (prostaglandin (PG)D2, PGE2, 6-keto-PGF1 alpha, and leukotriene (LT)C4) was measured at different intervals after SAH induction. Rats were separated into the following three groups: a sham-operated group, an SAH group (rats were injected with 0.3 ml autologous arterial blood), and an SAH-treated group (after SAH induction, rats were treated with nicardipine 1.2 mg/kg intraperitoneally). Nicardipine significantly decreased the ex vivo release of PGD2 at 48 hours after SAH (p less than 0.01). The release of PGE2 was significantly enhanced at 6 hours after SAH, while in the nicardipine-treated group PGE2 release is significantly reduced. Nicardipine also affects the lipoxygenase pathway, reducing the release of LTC4 at 1, 6, and 48 hours after SAH induction. The results of the present study show that nicardipine treatment exerts an inhibitory effect on both biochemical pathways of arachidonic acid metabolism; aside from vascular effects, nicardipine could exert a protective role against the release of arachidonate metabolites, which could play a significant role in the pathogenesis of brain damage after SAH.