Viral Infections of Toronto Children During 1965: II. Measles Encephalitis and Other Complications

Among 16 cases of measles encephalitis observed in Toronto during 1964 and 1965, including six who were stuporous or comatose on admission and five who presented with convulsions, measles virus was isolated from CSF of one patient, rising titres of measles antihemagglutinin were detected in another patient, and 14 showed high antibody titres in sera collected as early as two to five days after onset of the measles rash. Increasing levels of measles antibody were detected in paired sera from three of seven patients with uncomplicated measles, and elevated antihemagglutinin titres were found in 16 cases of measles without neural involvement. Measles virus was isolated from lung tissue of a fatal case of giant cell pneumonia. Administration of pooled human gamma globulin to one leukemic patient, and of leukocytes from a convalescent donor to another leukemic child, may have assisted their recovery from measles.     

Computational approaches to hippocampal function.

The results of theoretical work have led researchers to suggest that the hippocampal formation may maximize its memory storage capacity by recoding events into patterns that are as dissimilar to one another, and which use as few neurons per event, as possible.     

The propagation of disturbance in savannas through food webs

Abstract. Savanna-grassland ecosystems are highly interactive due to effects among interconnected trophic elements. This can cause disturbance at one level in the trophic web to be propagated through that web to have effects far removed from the initial locus of disturbance. The reconstructed effects of rinderpest upon African savannas, acting directly upon susceptible grazers and browsers but in directly upon many other ecosystem components, are used as a case history illustrating the propagation of disturbance in savanna ecosystems.     

A Fourier transform infrared microspectroscopic imaging investigation into an animal model exhibiting glioblastoma multiforme

Glioblastoma multiforme (GBM) is a highly malignant human brain tumour for which no cure is available at present. Numerous clinical studies as well as animal experiments are under way with the goal being to understand tumour biology and develop potential therapeutic approaches. C6 cell glioma in the adult rat is a frequently used and well accepted animal model for the malignant human glial tumour. By combining standard analytical methods such as histology and immunohistochemistry with Fourier Transform Infrared (FTIR) microspectroscopic imaging and multivariate statistical approaches, we are developing a novel approach to tumour diagnosis which allows us to obtain information about the structure and composition of tumour tissues that could not be obtained easily with either method alone. We have used a “Stingray” FTIR imaging spectrometer to analyse and compare the compositions of coronal brain tissue sections of a tumour-bearing animal and those from a healthy animal. We have found that the tumour tissue has a characteristic chemical signature, which distinguishes it from tumour-free brain tissue. The physical-chemical differences, determined by image and spectral comparison are consistent with changes in total protein absorbance, phosphodiester absorbance and physical dispersive artefacts. The results indicate that FTIR imaging analysis could become a valuable analytic method in brain tumour research and possibly in the diagnosis of human brain tumours.     

Ammonia volatilization and the effects of large grazing mammals on nutrient loss from East African grasslands

Summary Ammonia volatilization losses measured from soils at seven sites in the Serengeti National Park, Tanzania during the 1986 growing season ranged from 2.78±0.49% to 25.03±1.34% of nitrogen applied. Although peak ammonia losses ranged from 0.071±0.018 to 0.404±0.040 g N m^-2 h^-1, rates dropped to zero within four days, and calculations reveal that volatilization losses represent minor fluxes in the context of the system's nitrogen cycling. Volatilization losses were inversely correlated with grazing intensity experienced by a site, and it appears that large ungulates themselves contribute to nutrient conservation throught indirect interactive effects on system processes.