Adenocarcinoma of the esophagus and the esophagogastric junction: positron emission tomography improves staging and prediction of survival in distant but not in locoregional disease.

In adenocarcinoma of the esophagus and esophagogastric junction for prognostication and treatment allocation, one prerequisite is accurate pretreatment staging. This staging, we hypothesized, would be improved by the use of positron emission tomography (PET). After 55 patients suitable for radical esophageal resection were staged with PET, spiral computed tomography (CT), and endoscopic ultrasonography (EUS), results were compared with histopathology and with survival.

Prospective analysis of accuracy of positron emission tomography, computed tomography, and endoscopic ultrasonography in staging of adenocarcinoma of the esophagus and the esophagogastric junction.

Background: Exact preoperative staging of esophageal cancer is essential for accurate prognosis and selection of appropriate treatment modalities.

Methods: Forty-two patients with adenocarcinoma of the esophagus or the esophagogastric junction suitable for radical esophageal resection were staged with positron emission tomography (PET), spiral computed tomography (CT), and endoscopic ultrasonography (EUS).

Results: Diagnostic sensitivity for the primary tumor was 83% for PET and 67% for CT; for local peritumoral lymph node metastasis, it was 37% for PET and 89% for EUS; and for distant metastasis, it was 47% for PET and 33% for CT.

Evidence for spatial heterogeneity in insulin- and exercise-induced increases in glucose uptake: studies in normal subjects and patients with type 1 diabetes.

It is unknown whether resistance to insulin- or exercise-stimulated glucose uptake reflects a spatially uniform or nonuniform decrease in glucose uptake within skeletal muscle. We compared the distributions of muscle glucose uptake and blood flow in eight patients with type 1 diabetes (age 24 +/- 1 yr, body mass index 22.0 +/- 0.

Positron emission tomography using(18)F-fluoro-deoxyglucose and euglycaemic hyperinsulinaemic glucose clamp: optimal criteria for the prediction of recovery of post-ischaemic left ventricular dysfunction. Results from the European Community Concerted Action Multicenter study on use of(18)F-fluoro-deoxyglucose Positron Emission Tomography for the Detection of Myocardial Viability.

Aims: To assess the accuracy of positron emission tomography to predict recovery of global cardiac function after revascularization in patients with coronary artery disease.

Methods And Results: One hundred and seventy-eight patients (157 male, 58+/-10 years) with coronary artery disease and left ventricular dysfunction (mean ejection fraction 39+/-14%) were enrolled in six European centres. They underwent a common protocol for the assessment of viability using(18)F-fluoro-2-deoxyglucose (FDG) positron emission tomography during a standardized euglycaemic hyperinsulinaemic glucose clamp before revascularization by either surgery (n=140) or angioplasty (n=38).

Resistance to exercise-induced increase in glucose uptake during hyperinsulinemia in insulin-resistant skeletal muscle of patients with type 1 diabetes.

Insulin and exercise have been shown to activate glucose transport at least in part via different signaling pathways. However, it is unknown whether insulin resistance is associated with a defect in the ability of an acute bout of exercise to enhance muscle glucose uptake in vivo. We compared the abilities of insulin and isometric exercise to stimulate muscle blood flow and glucose uptake in 12 men with type 1 diabetes (age 24 +/- 1 years, BMI 23.

Preserved relative dispersion but blunted stimulation of mean flow, absolute dispersion, and blood volume by insulin in skeletal muscle of patients with essential hypertension.

Background: We examined the integrity of the effects of insulin on mean muscle blood flow, flow heterogeneity, and blood volume in essential hypertension.

Methods And Results: Positron emission tomography, combined with [15O]H2O and [15O]CO as tracers for direct measurement of blood flow and volume in skeletal muscle, and a new bayesian iterative reconstruction algorithm allowing pixel-by-pixel quantitation of blood flow and flow dispersion, were used. Measurements were performed basally after an overnight fast and under normoglycemic hyperinsulinemic conditions in 11 newly diagnosed, untreated mildly hypertensive men (age, 35 +/- 1 years; body mass index, 25.

Insulin resistance in essential hypertension is characterized by impaired insulin stimulation of blood flow in skeletal muscle.

Objective: To determine whether insulin-stimulated blood flow in patients with mild essential hypertension is altered.

Subjects: Eleven untreated mildly hypertensive patients [aged 35 +/- 2 years, body mass index 25.1 +/- 0.

Myocardial efficiency during calcium sensitization with levosimendan: a noninvasive study with positron emission tomography and echocardiography in healthy volunteers.

Dynamic positron emission tomography (PET) with [11C]acetate allows noninvasive assessment of myocardial oxygen consumption. In combination with echocardiography, PET enables determination of cardiac efficiency (defined as useful cardiac work per unit of oxygen consumption). We used this approach to compare the effects of levosimendan, a Ca(2+)-dependent calcium sensitizer, with dobutamine and sodium nitroprusside in healthy male volunteers.

Quantitative blood flow measurement of skeletal muscle using oxygen-15-water and PET.

Unlabelled: The aim of the present study was to evaluate quantitation of muscle blood flow using [15O]H2O and PET.

Methods: The autoradiographic (ARG) and the steady-state methods using PET were used to measure femoral muscle blood flow. A simulation study was performed to examine the errors due to contamination of radioactivity in the blood content in muscle tissue, statistical noise and delay and the dispersion of the input curve in the ARG method.

Acute effects of celiprolol on muscle blood flow and insulin sensitivity: studies using [15O]-water, [18F]-fluorodeoxyglucose and positron emission tomography.

Objective: Recently the role of peripheral vasoconstriction in the aetiology of insulin resistance has been proposed. Celiprolol is a beta 1-selective adrenoceptor antagonist with partial agonist activity at the beta 2-receptor as well as vasodilator properties. The acute effects of celiprolol on skeletal muscle blood flow and insulin sensitivity were measured in this study.

Relationship between limb and muscle blood flow in man.

1. Since direct measurement of muscle blood flow in humans has been difficult, estimations of muscle flow have been made from measured total limb blood flow using a classic equation that predicts that the fraction of resting blood flow through muscle tissue decreases as total limb flow increases. 2.

Insulin increases blood volume in human skeletal muscle: studies using [15O]CO and positron emission tomography.

High insulin concentrations increase blood flow in the leg, but it is unknown whether this effect is associated with a change in muscle blood volume. In the present study, we used positron emission tomography combined with inhalation of [15O]carbon monoxide to quantitate the effect of insulin on skeletal muscle blood volume in humans. The reproducibility of the method was determined from two consecutive measurements performed in the basal state in five normal subjects.

Insulin action on heart and skeletal muscle glucose uptake in essential hypertension.

Essential hypertension is characterized by skeletal muscle insulin resistance but it is unknown whether insulin resistance also affects heart glucose uptake. We quantitated whole body (euglycemic insulin clamp) and heart and skeletal muscle (positron emission tomography and 18F-fluoro-2-deoxy-D-glucose) glucose uptake rates in 10 mild essential hypertensive (age 33 +/- 1 yr, body mass index 23.7 +/- 0.

The effect of insulin and FFA on myocardial glucose uptake.

In addition to direct stimulation of glucose uptake and metabolism in cardiac myocytes, insulin inhibits lipolysis and, thereby, reduces serum free fatty acid (FFA) concentrations. This, in turn, has been suggested to enhance myocardial glucose utilization. To study the mechanism of insulin action on myocardial glucose uptake (MGU) in vivo, five patients with stable coronary artery disease were studied with positron emission tomography (PET) and [18F]FDG.

Gender and insulin sensitivity in the heart and in skeletal muscles. Studies using positron emission tomography.

Good insulin sensitivity is independently associated with a low risk for coronary heart disease, but it is unclear whether this risk factor differs between men and women. We compared insulin sensitivity of glucose uptake directly in muscle and heart tissues between healthy women (age 29 +/- 2 years, body mass index [BMI] 22 +/- 1 kg/m2, VO2max 39 +/- 4 ml.kg-1.

Effect of antilipolysis on heart and skeletal muscle glucose uptake in overnight fasted humans.

We quantitated how lowering of free fatty acid (FFA) by an antilipolytic agent (acipimox) in the fasting state changes glucose uptake in heart and skeletal muscles. Glucose uptake in these tissues was measured two times in seven normal subjects, once after acipimox and once after placebo, using positron emission tomography-derived [18F]fluoro-2-deoxy-D-glucose kinetics. Plasma glucose and insulin remained at their fasting concentrations in both studies.

Enhancement of myocardial [fluorine-18]fluorodeoxyglucose uptake by a nicotinic acid derivative.

Unlabelled: Recently, the euglycemic hyperinsulinemic clamp technique was shown to give excellent image quality during metabolic steady-state conditions. Acipimox is a new potent nicotinic acid derivative that rapidly reduces serum free fatty acid (FFA) levels by inhibiting lipolysis in peripheral tissue.

Methods: To compare the effects of acipimox administration and insulin clamp on [18F]fluorodeoxyglucose ([18F]FDG) uptake and myocardial glucose utilization, five nondiabetic and seven type II diabetic patients who had had previous myocardial infarctions were studied twice: once during a clamp study and once after the administration of acipimox (2 x 250 mg orally).

Different alterations in the insulin-stimulated glucose uptake in the athlete's heart and skeletal muscle.

Physical training increases skeletal muscle insulin sensitivity. Since training also causes functional and structural changes in the myocardium, we compared glucose uptake rates in the heart and skeletal muscles of trained and untrained individuals. Seven male endurance athletes (VO2max 72 +/- 2 ml/kg/min) and seven sedentary subjects matched for characteristics other than VO2max (43 +/- 2 ml/kg/min) were studied.

Myocardial viability: fluorine-18-deoxyglucose positron emission tomography in prediction of wall motion recovery after revascularization.

To assess the value of positron emission tomography (PET) imaging with fluorine-18-deoxyglucose ([18F]FDG) in predicting cardiac wall motion recovery after revascularization, 48 consecutive patients with previous myocardial infarction were studied. The normalized [18F]FDG uptake at rest was assessed semiquantitatively and compared to perfusion at rest as studied by SPECT imaging. Wall motion was analyzed with echocardiography before and after revascularization.

In vivo effects of insulin on tumor and skeletal muscle glucose metabolism in patients with lymphoma.

Background: The anabolic properties of insulin have been suggested for use to reverse malnutrition associated with cancer. The host and tumor sensitivities to insulin are critical for such treatments, which aim to improve patient nutrition. The authors studied insulin effects on tumor and skeletal muscle metabolism with 2-[18F]-fluoro-2-deoxy-D-glucose ([18F]FDG) and positron emission tomography (PET).

The value of quantitative analysis of glucose utilization in detection of myocardial viability by PET.

To study whether absolute quantitation of regional myocardial glucose utilization (rMGU) enhances detection of myocardial viability, 70 nondiabetic patients with prior myocardial infarction and angiographically confirmed coronary artery disease were studied with [18F]FDG PET after oral glucose loading. Forty-eight patients were also revascularized and underwent echocardiography after revascularization to detect wall motion recovery. The rMGU was calculated in eight myocardial segments in each patient and the results were compared to normalized (relative) [18F]FDG uptake values.

Heart and skeletal muscle glucose disposal in type 2 diabetic patients as determined by positron emission tomography.

Myocardial and skeletal muscle glucose uptake was examined in 9 type 2 diabetic patients and 13 control subjects using PET and the insulin clamp technique. All subjects had clinically stable coronary heart disease. To simulate the clinical situation, diabetic patients were kept slightly hyperglycemic during the clamp study.

Euglycemic hyperinsulinemic clamp and oral glucose load in stimulating myocardial glucose utilization during positron emission tomography.

To enable assessment of myocardial viability, myocardial glucose utilization has commonly been stimulated by oral glucose loading. To compare the effects of glucose loading and insulin and glucose infusion (insulin clamp) on PET fluorodeoxyglucose ([18F]FDG) myocardial scan image quality and regional myocardial glucose utilization rate (rMGU), eight patients with angiographically documented coronary artery disease and previous myocardial Q-wave infarction were studied twice, once during insulin clamp and once 1 hr after oral glucose loading. The rMGU rates were derived by graphic Patlak analysis in 33 normal, 10 scar and 6 "hot spot" myocardial segments.