[Role of ultrasonic echo location in the diagnosis of nonspecific thoraco-abdominal aortoarteritis]. / Rol' ul 'trazvukovoi ekholokatsii v diagnostike nespetsificheskogo aortoarterita torakoabdominal'noi lokalizatsii.

Ultrasonic echo-location (UEL) was used in 14 patients with nonspecific thoracoabdominal aortoarteritis before and after surgical treatment. Ultrasonic data were compared with aortographic and intraoperative findings. Patients with atherosclerosis of the abdominal aorta and congenital hypoplasia of the latter made up the control group. UEL is regarded as a fairly informative method of the diagnosis of nonspecific aortoarteritis, as thickened walls of the aorta and other affected vessels as well as irregular indurations involving aortic walls and para-aortic fat are pathognomonic signs of nonspecific aortoarteritis that differentiate it basically from other kinds of lesions. Besides, UEL is capable of early detection of the condition and the assessment of the routes of pathologic spread. After surgery, UEL might be used to control the state of the alloprosthesis.

[Effect of diethylamine analog of ethmozine on parameters of fast sodium current in normal and depolarized myocardial fibers]. / Deistvie diétilaminovogo analoga étmozina na parametry bystrogo natrievogo toka normal'nykh i depoliarizovannykh volokon miokarda.

The effect of a diethylamine analog of ethmozine (DAAE) on fast sodium current of normal and depolarized frog atrial trabeculae was studied by means of the double sucrose gap technique. The depolarization of the fibers was produced both by increasing extracellular potassium concentration up to 8 +/- 9 mM and by current passing. The resting potential of normal fibers was within the range of 75-80 mV, and the depolarized one was within 65 +/- 60 mV. DAAE (8 X 10(-7) g/ml) reduced sodium conductivity, slowed inactivation and reactivation of fast sodium current and shifted the steady-state activation curve (h infinity) to a more negative potential, but the steady-state activation curve (m infinity) to a more positive potential. All these effects were expressed more considerably in the depolarized fibers. The depressing ability of DAAE is assumed to be due to high concentration of the drug in the membrane owing to its high solubility in lipids. The slowing of sodium reactivation and inactivation shows the existence of a receptor for DAAE linked with a h-gate. Prolonged antiarrhythmic action is accounted for by a very slow recovery of sodium current after the drug superfusion. A stronger effect of DAAE on sodium current in the depolarized fibers is likely to point to its selective action on ischemic tissue.

[Lidocaine action on the ion currents of normal and depolarized myocardial fibers in membrane potential fixation]. / Deistvie lidokaina na ionnye toki normal'nykh i depoliarizovannykh volokon miokarda v usloviiakh fiksatsii membrannogo potensiala.

The effect of lidocaine on the transmembrane ion currents of normal and partially depolarized atrial trabecula was studied in the frog by fixation of membrane potential with duoble sucrose bridge. Lidocaine in a concentration below 12 X 10(-4) g/ml produced no effect on the slow input current. Lidocaine decreased the potassium conduction at the membrane potential values below--45 mW, and increased at--30 mW. Kinetic parameters of the rapid input sodium current and its amplitude significantly changed under the action of lidocaine in normal cardiac tissue, and its effect increased in the depolarized tissue. It is suggested that depolarization is a factor increasing sensitivity to lidocaine of rapid sodium canals, while the capacity of lidocaine to inhibit effectively the rapid sodium current in the partially depolarized myocardium determine its antiarrhythmic activity.