Melatonin ameliorates cerebral vasospasm after experimental subarachnoidal haemorrhage correcting imbalance of nitric oxide levels in rats.

In the present study, we investigated the in vivo effects of melatonin on SAH-induced cerebral vasospasm and oxidative stress, resulting from SAH in an experimental rat model. Twenty-eight rats (225-250 g) were divided into four groups equally: group 1; control, group 2; SAH, group 3; SAH plus placebo, and group 4; SAH plus melatonin. We used double haemorrhage method for SAH groups. Beginning 6 h after SAH, 20 mg/kg melatonin or equal volume of 0.9% saline was administered intraperitoneally twice daily for 5 days to groups 3 and 4, respectively. Melatonin or 0.9% saline injections were continued up to fifth day after SAH and rats were sacrificed at the end of this period. Brain sections at the level of the pons were examined by light microscopy. The lumen diameter and the vessel wall thickness of basilar artery were measured using a micrometer. The serum levels of cerebral vasodilator nitric oxide (NO), the brain levels of an intrinsic antioxidant superoxide dismutase (SOD) and a NO regulator arginase activities were measured. The brain levels of inducible nitric oxide (iNOS) and nitrotyrosine, a nitrosative stress parameter immunohistochemiacally determined. In conclusion, melatonin administration ameliorated cerebral vasospasm by increasing serum NO level and decreasing the brain the levels of arginase and oxidative stress. It is therefore possible that increased brain arginase activity after SAH may also have a significant role in the pathogenesis of vasospasm by limiting the availability of arginine for NO production.

The attenuation of vasospasm by using a sod mimetic after experimental subarachnoidal haemorrhage in rats.

BACKGROUND: Delayed cerebral vasoconstriction and brain ischemia, are critical problems in the management of a patient affected by rupture of an intracranial aneurysm. Overexpression of Cu-Zn superoxide dismutase (Cu-Zn SOD) can reduce the extent of cerebral vasospasm. We, therefore investigated if vasospasm, can be prevented by a novel, stable, and cell permeable SOD mimetic, MnTBAP [Mn(III) tetrakis (4-benzoic acid) porphyrin] which permeates the biological membranes and scavenges superoxide anions and peroxynitrite. METHODS: 28 rats (225-250 g) were divided equally into four groups: group 1: control; group 2: SAH only; group 3: SAH plus placebo; and group 4: SAH plus MnTBAP. We used a double haemorrhage method to produce SAH. Starting six hours after SAH, 5 mg/kg MnTBAP (Calbiochem, Darmstadt-Germany; Cat. No 475870)) or an equal volume of 0.9% saline (37 degrees C) was administered by intraperitoneal injection twice daily for 5 days to groups 4 and 3 respectively. MnTBAP or 0.9% saline injections were continued up to fifth day after SAH and rats were sacrificed on the fifth day. Brain sections at the level of the pons were examined by light microscopy. Planimetric measurements were made for the cross-sectional areas of the lumen and the vessel wall (intima plus media) of the basilar artery by a micrometer. FINDING: Administration of MnTBAP significantly attenuated the vasoconstriction of the basilar artery in group 4 compared with the groups 2 and 3 (p<0.001). INTERPRETATION: These results suggest that this SOD mimetic (MnTBAP) attenuates delayed cerebral vasoconstriction following experimental SAH and that superoxide anions have a role in the pathogenesis of vasospasm after SAH.

Melanoma metastatic to the spine: a review of 133 cases.

Although spine metastasis from melanoma is an uncommon event, it can pose a complex management problem. The presentation and natural history of melanoma metastatic to the spine has not been described in the medical literature. We have conducted a review of the records of 133 patients with melanoma metastatic to the spine in order to obtain retrospective data on demographic information, clinical presentation, disease course and survival. Patients with cutaneous, ocular and mucosal melanoma were all represented, but those with primary cutaneous tumours of the trunk were more prevalent than expected. Other sites of metastatic disease were present in nearly all patients and metastases to other skeletal sites were not unusual. Pain was the most common presenting symptom. The radiographic diagnosis was generally made easily by plain radiographs, computed tomography or magnetic resonance imaging, with the most frequent finding being a destructive lesion. Bone scan gave false-negative results 15% of the time. The median survival for the group was 4 months. It is concluded that melanoma metastatic to the spine represents a late event in the evolution of this illness. Palliation should be the goal of treatment, but symptom management should be individualized, bearing in mind the short anticipated survival of these patients.

Unusual frontal osteoma, mimicking a haemangioma.

We report a patient with a frontal bone osteoma showing the classical findings of haemangioma. A craniectomy and total tumour excision was carried out.

A huge cerebral hydatid cyst associated with small liver cyst: a comparison of growth rates and sizes.

There are still some unknown aspects of the natural course of echinococcus infestation, especially in the brain. The growth rate of the cysts in brain and in other tissues is matter of some discussion. In this report, a huge primary cerebral hydatid cyst associated with a small liver cyst is presented and a possible relationship between the growth rates and the sizes of the two cysts is discussed. It is shown that the brain hydatid cyst grew faster than liver hydatid cyst by a ratio of 3:1.

Clinical analysis of cerebral abscesses.

42 patients with cerebral abscesses were treated from 1979 until the end of the first six months of 1987 at the Neurosurgical Department of the Faculty of Medicine, Atatürk University, Erzurum, Turkey. The present study aims at studying these patients to determine the factors affecting on prognosis. The patients were studied for the duration of complaints, pre-operational condition, the location of the abscesses, the microorganisms responsible for them, and the techniques of operation applied, by taking their sex and age into consideration. All of the cases were treated operatively. Of these, 18 were treated by excision and 24 were applied drainage, whose percentage was 43 and 57 respectively, 85% of the cases were under 60 years of age. The rate of mortality of the cases with cerebral abscesses was 19%. This rate was between 15% and 37.5% in the cases of several age groups whose complaints lasted less than two months. This rate reached 100% with a sudden increase in the cases who had a duration of complaints over four months. The rate of mortality was 6.2% in the cases with a clear conscious and cooperative ability while it had a significant increase in the patients in pre-coma or coma to go up to 50% and 75% respectively. No correlation was observed between the rate of mortality and the age of the patients but the location and extension of the abscesses had an effect on this rate. The abscesses, covering more than one lobe, had a mortality rate of 31.2%, while the ones with parietal location caused no single death. To conclude, we can say, based on this study, that the age and sex of patients and the operative technique have no effect on the rate of mortality while it is obviously influenced by the duration of the complaints and the pre-operative condition. Consequently, we would like to stress up on early diagnosis and treatment of such cases.