ABSTRACT
Although cocaine abuse has been associated with an increased incidence of cerebrovascular accident, the underlying mechanisms are unknown. In this study we have investigated the effects of cocaine upon the autoregulation of local cortical blood flow (lCBF) during hypertension. Hypertension was induced in conscious rats by intravenous infusion of angiotensin-II (5 micrograms/ml; 0.5-2.5 ml/h), and animals were subsequently injected IV with either cocaine-HCl (5 mg/kg) or saline, prior to the measurement of lCBF of glucose utilization (lCGU) using [14C]-iodoantipyrine or [14C]-2-deoxyglucose quantitative autoradiography, respectively. Hypertension alone (< 155 mmHg) did not significantly alter lCBF in any cortical areas examined. However, at higher mean arterial blood pressure (MABP), lCBF increased focally (+265%) in parietal cortex. Cocaine did not alter lCBF in normotensive animals, but with increasing levels of hypertension (MABP > 145 mmHg), all cocaine-treated rats showed focal increases (200-400%) in lCBF in parietal cortex. Glucose use remained relatively unaffected in all treatment groups. This hyperaemia in cocaine-treated rats at MABP below the normal upper limit of autoregulation may provide a mechanism to explain haemorrhagic stroke in cocaine abusers.
Subject(s)
Cerebral Cortex/physiology , Cerebrovascular Circulation/drug effects , Cocaine/pharmacology , Hemodynamics/drug effects , Angiotensin II/pharmacology , Animals , Autoradiography , Blood Pressure/drug effects , Brain Chemistry/drug effects , Cerebral Cortex/anatomy & histology , Cerebral Cortex/drug effects , Glucose/metabolism , Hyperemia/physiopathology , Injections, Intravenous , Male , Rats , Rats, Sprague-DawleyABSTRACT
The medical records of all patients treated for Hodgkin's disease during the years 1964-1981 were reviewed. Four hundred seventy-three previously untreated patients were analyzed. Thirty-four subsequent second malignant neoplasms were observed in 33 patients among those treated for Hodgkin's disease. Eight cases of acute nonlymphocyctic leukemia, one case of chronic myeloid leukemia, three cases of non-Hodgkin's lymphoma, three cases of sarcoma, and 19 other tumors were identified. The ten-year estimated risk of leukemia by treatment was the following: radiotherapy only (0), chemotherapy only (0.02), initial combined radiotherapy-chemotherapy (0.06), and salvage combined radiotherapy-chemotherapy (0.09). The ten-year estimated risk of solid tumors was 0.07 overall, with all treatment groups associated with similar risks. Unlike some other reports, a greater risk of leukemia in patients who began treatment for Hodgkin's disease at age 40 or older was not found. However, a positive association was noted between increasing risk of solid tumors and increasing patient age.
