Experimental pig model of old myocardial infarction with long survival leading to chronic left ventricular dysfunction and remodeling as evaluated by PET.

Unlabelled: A pig model of reduced left ventricular (LV) function and remodeling or chronic heart failure with long survival after myocardial infarction (MI) has not been established. The aim of this study was to evaluate the pathophysiologic status of a pig model of old MI using a series of PET studies.

Methods: Twenty-seven male farm pigs were divided into 2 groups: 7 animals in the control group and 20 animals that underwent a proximal coronary artery (CA) occlusion using an ameroid constrictor after distal CA ligation.

Evaluation of left ventricular function with cardiac magnetic resonance imaging using Fourier fitting.

The aims of this study were to investigate the applicability of Fourier fitting in the magnetic resonance (MR) evaluation of left ventricular (LV) function and to determine the optimal number of harmonics for fitting. Cine cardiac MR imaging was performed in 10 subjects, and an LV time-volume curve was generated. Fourier fitting was applied to the original curve using 1-10 harmonics, and the qualities of the time-volume curve and first-derivative curve were evaluated.

Proposal of blood volume-corrected model for quantification of regional cerebral blood flow with H2 15O-PET and its application to AVF.

Purpose: It is generally assumed that vascular tracer activity is negligible in the quantification of regional cerebral blood flow (rCBF) with H2 15O and positron emission tomography (PET) under normal conditions. We attempted to surpass the assumption of abnormal vascular conditions where the vascular tracer activity is significant by introducing the vascular component into the model.

Materials And Methods: H2 15O-dynamic and C15O PET scans were performed in an arteriovenous fistula (AVF) patient.

Myocardial glucose utilisation in type II diabetes mellitus patients treated with sulphonylurea drugs.

Purpose: Chronic sulphonylurea treatment maintains improved glycaemic control through mechanisms other than enhancement of insulin secretion and may act on various organs. The aim of this study was to investigate whether the chronic use of sulphonylurea drugs influences PET measurement of myocardial glucose utilisation (MGU) in type II diabetes mellitus.

Methods: Forty-two patients with type II diabetes mellitus and 17 control subjects underwent dynamic (18)F-FDG PET to measure MGU during hyperinsulinaemic euglycaemic clamping.

Measurement of skeletal muscle glucose utilization by dynamic 18F-FDG PET without arterial blood sampling.

Objective: Skeletal muscle glucose utilization (SMGU) can be measured by 18F-FDG PET to characterize insulin resistance. The aim of this study was to determine whether femoral muscle SMGU can be measured without arterial blood sampling by sequential PET imaging of the thoracic and femoral regions.

Methods: Ten patients with possible insulin resistance underwent dynamic 18F-FDG PET of the femoral region during hyperinsulinaemic euglycaemic clamping (group A), and femoral muscle SMGU was calculated using PET data of various time periods and measured arterial input.

Prolonged renal parenchymal retention of 99mTc mercaptoacetyltriglycine after nephron-sparing surgery.

Objective: Nephron-sparing surgery is a treatment in which a part of a diseased kidney is resected and some parenchyma of the kidney is spared. Impairment of spared renal parenchyma after the surgery may cause prolonged prarenchymal retention in renal scintigraphy with Tc mercaptoacetyltriglycine (Tc-MAG3). The aim of this study was to determine whether or not parenchymal retention of Tc-MAG3 is prolonged after nephron-sparing surgery.

Impaired myocardial vasodilatation during hyperaemic stress is improved by simvastatin but not by pravastatin in patients with hypercholesterolaemia.

Aims: Impaired myocardial vasodilatation during hyperaemic stress with dipyridamole has been documented in hypercholesterolaemics without evidence of ischaemia. This study investigated whether two commonly used hydroxymethylglutaryl coenzyme A reductase inhibitors, simvastatin and pravastatin, are equally effective in restoring myocardial vasodilatation.

Methods And Results: Forty-four hypercholesterolaemics with a low probability of coronary artery disease and 22 controls were studied.

Common carotid intima-media thickness is correlated with myocardial flow reserve in patients with coronary artery disease: a useful non-invasive indicator of coronary atherosclerosis.

Background: The common carotid intima-media thickness (IMT) is correlated with the angiographically determined coronary artery stenosis. However, their correlation is weak, which limits the clinical application of the IMT as a predictor of coronary artery stenosis. The IMT reflects diffuse early-phase atherosclerosis, whereas the angiographically determined coronary artery stenosis is a late-phase phenomenon.

Simple quantification of skeletal muscle glucose utilization by static 18F-FDG PET.

Unlabelled: Skeletal muscle glucose utilization (SMGU) can be measured by dynamic PET imaging with (18)F-FDG to characterize insulin resistance. The aim of this study was to determine the validity of simple methods to quantify SMGU by static PET imaging.

Methods: Ten patients underwent dynamic (18)F-FDG PET of the femoral region during hyperinsulinemic euglycemic clamping.

Caveolin-3 is Up-Regulated in the Physiological Left Ventricular Hypertrophy Induced by Voluntary Exercise Training in Rats.

Various substances have been introduced in relation with cardiac hypertrophy almost always with controversy in their roles in signal transduction. Those controversies may attribute to the diversity of cardiac hypertrophy. We previously showed that calcineurin was activated in physiological left ventricular hypertrophy (LVH) induced by voluntary exercise training, but not in decompensated pressure-overload LVH.

Regional changes in human cerebral blood flow during dipyridamole stress: neural activation in the thalamus and prefrontal cortex.

Intravenous dipyridamole increases the concentration of circulating adenosine and produces coronary vasodilation. However, it decreases global cerebral blood flow (CBF) due to hyperventilation side effect of adenosine. In the present study, changes in regional CBF during dipyridamole stress were identified in detail.

Reduced myocardial flow reserve in anatomically normal coronary arteries due to elevated baseline myocardial blood flow in men with old myocardial infarction.

Background: Decreased myocardial flow reserve (MFR) in angiographically normal coronary arteries in patients with old myocardial infarction (OMI) has been reported.

Methods And Results: To clarify factors for the reduced MFR in OMI and to compare them with those in angina pectoris (AP), baseline myocardial blood flow (MBF) and MBF during dipyridamole administration were measured with nitrogen 13 ammonia positron emission tomography, after which MFR was calculated for 13 men with AP, 18 men with OMI, and 15 age-matched male control subjects. MFR was compared among the 3 groups in segments perfused by nonstenotic arteries.