Assessment by dipyridamole-thallium-201 myocardial scintigraphy of coronary risk before peripheral vascular surgery

From October 1983 to January 1985, 46 patients (38 men and 8 women; average age, 60 years; range, 37 to 83 years) underwent peripheral vascular surgery of either the internal carotid artery or the arteries of the lower limbs. Each patient had a thorough clinical examination, an ECG, and a dipyridamole-thallium-201 myocardial scan before operation. On the basis of results, they were divided into two groups: 20 patients with and 26 patients without chronic ischemic heart disease. Three major cardiac events were noted during or after a period of 1 month after surgery: There were two deaths due to cardiac ischemic events and one patient had postoperative unstable angina pectoris. These three patients were classified in the coronary group (NS). When the patients were classified on the basis of whether or not there was thallium redistribution on serial images after infusion of dipyridamole, 14 with redistribution and 32 without redistribution were noted. The three patients who had major cardiac events were in the former group (p less than 0.04). Our data suggest that patients in whom redistribution occurs have a high incidence of postoperative ischemic events. These patients should be considered for particular preoperative coronary care to avoid major postoperative cardiac events and to increase chances of survival.     

Induction of hepatic glycogen synthesis by glucocorticoids is not mediated by insulin

Administration of 0.1 or 1 mg of prednisolone to fed mice caused a 5-fold activation of glycogen synthase in the liver after 3 h, without significant changes in the circulating levels of glucose or insulin, or in the hepatic concentration of cyclic AMP. Adrenalectomized fasted rats responded to Cortisol (10 mg) with an increased glycaemia and a progressive activation of hepatic glycogen synthase after 2–4 h, but without an increase in the very low insulinaemia.These results are incompatible with the prevailing hypothesis that glucocorticoids provoke hepatic glycogen synthesis through an extra secretion of insulin. It is discussed that the acute effect of glucocorticoids is to inhibit rather than stimulate the release of insulin.     

Temporal nulling of induction from spatial patterns modulated in time

Temporally varying chromatic-inducing light was used to infer receptive-field organization. Time-varying shifts in color appearance within a test field were induced by a surrounding chromatic pattern; the shifts were then nulled by adding a time-varying stimulus to the test area so the observer perceived a steady test. This method measured chromatic induction without requiring an observer to judge the color appearance of the test. The induced color shifts were consistent with a +s/-s spatially antagonistic neural receptive field, which also accounts for color shifts induced by static chromatic patterns (Monnier & Shevell, 2003, Monnier & Shevell, 2004). The response of this type of receptive-field, which is found only in the visual cortex, increases with S-cone stimulation at its center and decreases with S-cone stimulation within its surround. The measurements also showed a negligible influence of temporal inducing frequency in the range 0.5-4 Hz.     

Evaluation of the therapeutic response: role of isotopic imaging

In comparison with conventional imaging, nuclear medicine offers an original metabolic approach for the assessment of the therapeutic response. Gallium 67, thallium 201, technetium 99m-labeled sestamibi and diphosphonates can be performed for therapeutic response assessment in lymphoma, brain and breast tumours, sarcoma, or bone metastasis. PET-CT facilities are now easily available in France and are ready to provide a new and accurate tool in oncology, specially for therapeutic evaluation. The procedure consists in the injection of fluor-18-fluoro-déoxyglucose (18FDG), an analogue of glucose, followed by a PET then a CT acquisition for FDG uptake abnormalities location. Therapeutic response is assessed by a decrease of 18FDG tumoral uptake between two consecutive studies. Methodology and interpretation criteria have been recently defined in international guidelines. 18FDG-PET-CT seems to be a valuable tool for therapeutic response assessment of patients with Hodgkin or non Hodgkin malignant lymphoma. Promising preliminary results have been recently published for lung, gastro-intestinal and head and neck cancers. PET-CT could also be able to predict the therapeutic response after the first courses of chemotherapy, allowing an early treatment optimization. Finally, new PET agents pave the way for molecular imaging with promising results in gene therapy and targeted treatment in oncology.