[Comparison of high-resolution arterial echography and angiography in the diagnosis of atheromatous lesions of the external carotid]. / Confronto tra ecografia arteriosa ad alta risoluzione ed angiografia nella diagnosi delle lesioni ateromasiche della carotide extracranica.

Personal experience about a correlative study on ultrasonographic and angiographic methods executed on carotid artery is reported. Usual techniques are described and result discordances are considered. Stenosis level is subdivided in four different types: normal, less than 45, 45-75%, greater than 75%. Authors examine in which stenosis range one technique can be superimposed on the other one and show limits and possibilities. Moreover complementary and interdependence position of these two techniques are stressed with respect to atherosclerotic disease study.

Alterations in norepinephrine content and beta adrenoceptor regulation in myocardium bordering aneurysm in human heart: their possible role in the genesis of ventricular tachycardia.

On the assumption that alterations in the adrenergic system may play a role in generating ventricular tachycardia in patients with myocardial post-infarction apical aneurysm, we evaluated norepinephrine concentration, number and affinity of both beta 1 and beta 2 adrenoceptors in perianeurysmatic tissue in twelve patients operated upon for congestive heart failure and recurrent sustained ventricular tachycardia. Concentration of norepinephrine in perianeurysmatic tissue was 0.1 +/- 0.05 micrograms g-1 tissue (n = 8), this value being much lower than that found in papillary muscle (n = 10) from patients with mitral valve stenosis (0.8 +/- 0.02 micrograms g-1 tissue) (P less than 0.01). The total number of beta adrenoceptors (71.4 +/- 7.8 v. 48.0 +/- 5.1 fmol mg-1 protein; P less than 0.01) and the percentage of beta 1 subtype were found to be higher in perianeurysmatic tissue (approximately 90%) than in papillary muscle (approximately 68%). Out of twelve patients with aneurysm, beta 2 adrenoceptors had considerably decreased in three patients and were absent in the remaining nine. Decrease in the neuronally released norepinephrine associated with contrasting behaviours of beta 1 and beta 2 adrenoceptors suggests the presence of a profound alteration in the sympathetic innervation of the perianeurysmatic myocardial tissue that may contribute to the genesis of sustained ventricular tachycardia in patients with postinfarction apical aneurysm.

Effects of potassium supplementation on insulin binding and insulin action in human obesity: protein-modified fast and refeeding.

To investigate the role of potassium deficiency in the development of glucose intolerance during caloric deprivation, potassium balance was maintained within normality with oral potassium supplementation in a group of obese subjects who underwent protein-modified fast and the results of the study of carbohydrate metabolism (oral glucose test, insulin receptors on monocytes and peripheral glucose utilization as assessed by euglycaemic clamp) were compared with those obtained in a group of obese subjects admitted to protein-modified fast without potassium supplementation. Caloric deprivation without oral potassium supplementation was followed by a negative potassium balance and a decrease of serum potassium levels; a decrease of the peripheral levels of insulin along with an increase in insulin receptors and a striking reduction of peripheral glucose utilization were also observed. The maintenance of normal potassium balance and normal serum potassium levels with oral potassium-chloride supplementation was associated with higher peripheral levels of insulin (P less than 0.01) and improvement of peripheral glucose utilization (P less than 0.01) whereas the binding of insulin to monocytes was unchanged. The data suggest that potassium depletion during protein-modified fast causes a decrease of the peripheral levels of insulin and a resistance to insulin action at the postreceptors sites which is reversed by potassium supply.

Comparison of rat and human left ventricle beta-adrenergic receptors: subtype heterogeneity delineated by direct radioligand binding.

Beta adrenergic receptors were identified in rat myocardial left ventricle and human papillary muscle by using the antagonist radioligand 3H-dihydroalprenolol. The number (37.3 and 44.5 fmol/mg of protein, respectively in rat and man), and the KD (1.6 and 2.8 nM, respectively in rat and man) of beta receptors were not significantly different. Adrenergic receptors of both beta 1 and beta 2 subtypes were found to coexist in the left ventricle. The relative proportions of the two beta receptor subtypes were determined by the use of competition radioligand selective binding and computer modelling techniques employing the subtype selective antagonists ICI 118,551 (beta 2 selective) and atenolol (beta 1 selective) in rat or metoprolol (beta 1 selective) in man. The rat left ventricle contained about 74% beta 1 and 26% beta 2 adrenergic receptors, human left ventricle papillary muscles contained about 69% beta 1 and 31% beta 2. Human and rat left ventricles contain both beta 1 and beta 2 adrenergic receptors with similar affinities. Rat might be a model for the study of human myocardial beta adrenergic receptors.

Radioisotope cisternography in head-injured patients.

Of 600 patients submitted to radioisotope cisternography carried out with radioiodinated human serum albumin (I131-HSA) a group of 140 had head injuries. Our investigation was intended to study the modifications of CSF circulation and absorption which accompany cranio-cerebral trauma. Of 88 head injured patients who did not undergo operation 44 had transient loss of consciouness, and 44 were in prolonged coma. Fifty-two patients underwent operation. Of these 5 had skull fractures with dural lesions, 7 had extradural haematomas, 19 had subdural haematomas, and 21 had brain contusions. Cisternograms were performed at different time intervals after trauma, and in some instances the test was repeated in order to study the possible long tern alterations of CSF circulation and absorption. Abnormalities of cisternographic pictures are classified into the following groups: 1 degree asymmetric diffusion; 2 degree operative cavity stagnation; 3 degree ventricular reflux; 4 degree associated abnormalities. Cisternographic features are analysed in relation to the corresponding clinical and pneumoencephalographic patterns in the patients examined. These investigations may enable us to recognise possible indications for shunt procedures in the management of CSF absorption defects, which are so frequently apparent after head injury.