Extranodal Ki-1 lymphoma in a renal transplant patient

THe Ki-1 (CD 30) antigen has been identified as a marker of a subset of large cell anaplastic non-Hodgkin's lymphoma that may have a more favourable prognosis. We describe an immunosuppressed renal transplant patient who developed primary extranodal large cell anaplastic Ki-1 lymphoma of T-cell phenotype confined to the sigmoid colon. The patient was treated with local resection of the sigmoid colon and reduction of immunosuppression and at two year follow-up remains free of recurrence. It is recognised that long term immunosuppression in post transplant patients increases the risk of certain malignancies. Localised gut lymphoma may be amenable to local resection as a curative procedure.

Topography, extent, and clinical relevance of neurochemical deficits in dementia of Lewy body type, Parkinson's disease, and Alzheimer's disease

Cholinergic and monoaminergic (dopaminergic and serotonergic) activities have been examined in postmortem brain tissue in senile dementia of Lewy body type, Parkinson's disease, and Alzheimer's disease. Quantitative data suggest that although extrapyramidal symptoms relate to striatal levels of dopamine, cognitive impairment is most closely associated with cholinergic (but not monoaminergic) deficits in temporal and archicortical areas. Hallucinations, which are most frequent in Lewy body dementia, appear to be related to an extensive cholinergic deficit in temporal neocortex and the resulting imbalance between decreased cholinergic and relatively preserved serotonergic activities. Topographic analyses such as these including consideration of quantitative "threshold" effects, may be relevant to the future anatomic focus of neurochemical investigations in dementia and to the development of appropriate experimental models.