General protease and collagenase IV activity are involved in the remodelling of the vascular basement membrane that occurs during tumor-induced angiogenesis. This study has assessed the level of these enzymes in tumor, peritumoral or contralateral cerebral cortex tissue during the growth of C6 astrocytoma in the rat spheroid implantation model. General proteolytic activity was increased in tumor tissue beginning on day 8 following spheroid implantation, then increased to a maximum value on day 11 and decreased to control values on day 18. A similar pattern was seen for collagenase IV activity but maximal activity occurred on day 13. The peritumor and tumor patterns of activity were similar. General protease activity was increased in the hemisphere contralateral to the tumor suggesting that the growth of C6 astrocytoma in rat brain was influencing biochemical events distant from the tumor. C6 astrocytoma cells orchestrate a cascade of proteolytic events which may play a crucial role in angiogenesis associated with tumor growth in the model system studied.

Twenty-five patients with spinal epidural abscess were treated at the University of Western Ontario hospitals between July 1980 and July 1990. There were eighteen males (72%) and seven females (28%), with a median age of 60 years. Concurrent illness resulting in immunocompromise was present in 60%. Eleven presented with complete myelopathy, thirteen had limb weakness, and one had no neurological deficit. In twenty cases the abscess consisted of frankly purulent material, while in five the epidural collection consisted of chronic granulation tissue. Staphylococcus aureus was isolated in 64% of the abscesses. Twenty-seven surgical procedures were performed on 21 patients. Ten cases occurred in the cervical spine (40%), seven in the thoracic spine (28%), three in both the cervical and thoracic spine (12%) and five in the lumbosacral spine (20%). Fourteen patients (56%) retained or recovered ambulation and there were five deaths (20%). The progression from back and radicular pain to weakness and eventual paralysis continues to be characteristic of spinal epidural infection. Morbidity and mortality remain unacceptably high because of delay in diagnosis and treatment. Magnetic resonance imaging is the radiological investigation of choice for the diagnosis of spinal epidural abscess. Prompt intervention, before the development of severe neurological deficits, can improve outcome. Immediate surgical drainage combined with antibiotics remains the treatment of choice.

A potent in vitro inhibitor of lipid peroxidation, U78517F, has been employed to assess its influence on C6 astrocytoma growth in monolayer culture and tumor growth and protein extravasation in the rat C6 astrocytoma spheroid implantation model. Results demonstrate that 1 μM concentration of U78517F inhibits cell division, but is not tumoricidal to C6 astrocytoma cells in monolayer culture. Concentrations of 5 μM and above significantly decreased astrocytoma cell viability. Following spheroid implantation, rats were treated with one of these U785I7F regimes: 12 mg/kg/day for 13 days post-implantation, 4 mg/kg/day for 13 days post-implantation or 12 mg/kg/day commencing seven days post-implantation until 13 days post-implantation. Tumor wet and dry weights were lower in all treatment groups, but these decreases were not statistically significant. Protein extravasation as measured by Evans blue extravasation was not significantly reduced by any treatment regime used. It is concluded that U78517F inhibits C6 astrocytoma growth in monolayer culture at and above 5 μM concentrations, but the treatment regimes utilized did not significantly decrease tumor growth or permeability in the C6 astrocytoma spheroid implantation model.

An understanding of the mechanisms responsible for tumor-associated edema involves the elucidation of the role played by a number of intra-related processes. These include (i) the permeability of new tumor microvessels that are associated with tumor angiogenesis; (ii) alterations in microvascular permeability due to factors secreted by tumor cells; (iii) immunological mechanisms and (iv) increased microvessel permeability associated with inflammation. The rationale for a role for inflammatory processes in tumor-associated edema has been outlined and the role of non-steroidal anti-inflammatory drugs in modulating experimental and human tumor-associated edema has been explored.

Six hundred and fifty-two patients with histologically proven primary malignant melanoma have been followed by the London Regional Cancer Centre from 1960 to 1985. Neurological signs and symptoms secondary to metastases to the brain developed in fifty-five patients (8.4%). The median age was 49 years; 71% were male and 29% female. Multiple lesions were found in 61% and a single metastasis in 39%. The most common site for the primary lesion was the trunk in males (44%) and the lower limb in females (37%). Six month survival for patients with a single metastasis was 58% if surgical excision was possible and 25% of these patients survived greater than two years. In patients with multiple metastases that received radiotherapy, survival times of greater than six months were found in 12% of the patients. Patients with a single metastasis appear to benefit by being managed by surgical removal of the lesion.