Sources of the innervation of the carotid reflexogenic zone in representative reptiles

The investigation is dedicated to study sources of the carotid reflexogenic zone innervation in 43 tortoises (Testudo horsfieldi and Emys orbicularis). In 7 tortoises fine preparation of the vessels and nerves of the cervical area after V. P. Vorob'ev has been performed. In 13 animals descending branch of the glossopharyngeal nerve has been resected. In 4--the caudal ganglion of this nerve and in 9 tortoises the caudal ganglion of the vagus nerve have been resected. In 10 tortoises adrenergic nervous plexuses are studied after Falck-Govyrin method, and cholinergic ones--after Karnovsky-Roots. As demonstrate anatomical investigations, to the carotid reflexogenic zone of the tortoises, situating in the area of the common carotid artery base, the branches of the glossopharyngeal and of the vagus nerve approach. The experiments with resection of these nervous conductors demonstrate that by the end of 3 days after the operation myelin nervous fibers of various thickness are at the stage of granular decay. Cholinergic and adrenergic nervous fibers and plexuses are revealed histochemically in the carotid zone.     

Effect of heart electric stimulation on repolarization of ventricular myocardium of fish and amphibians

The distributions of repolarization durations and end of repolarization time were studied on the ventricular epicardium in pikes (Esox lucius) and frogs (Rana esculenta) and in the ventricular intramural layers in toads (Bufo bufo) at the ectopic heart excitation by using method of the synchronous multielectrode cartography (24 unipolar leads). The time of arrival of the excitation wave and the end of repolarization in each lead were determined from the minimum of time derivative of potential at the period of QRS complex and by minimum of T wave, respectively. It has been established that at the ventricle electrostimulation, alongside with deceleration and a change of sequence of myocardium activation, the redistribution occurs of the local durations of repolarization, being longer than in zones of early activation (p < 0.05). At stimulation, the apicobasal gradient of repolarization is predominantly changed due to electrophysiological processes in the apical areas. In all the studied species, at the ectopic excitation of the heart the sequence of its repolarization repeats the depolarization sequence due to a delay of activation (in fish) and redistribution of repolarization durations (in amphibians).     

Rheumatoid involvement of the aortic arch

The clinical course of rheumatoid arthritis may be complicated by cardiac involvement. Indeed, postmortem studies suggest rheumatoid involvement in up to 50% of pericardial, 5% of myocardial, and 60% of valvular specimens. Yet, in our search of the literature, we found only a single case report describing aortic valve replacement for rheumatoid valvulitis. This discrepancy may be related to the paucity of symptoms in this sedentary group of patients. A complete cardiac evaluation of patients with rheumatoid arthritis is recommended to select those with significant valvular involvement for timely surgical intervention prior to the development of irreversible left ventricular dysfunction. Two patients who benefitted from aortic valve replacement for rheumatoid valvular disease are presented.     

Erythrocyte distribution in the vascular bed at the level of the aortic arch based on morphological research data

Erythrocyte distribution in the vascular bed according to their maturation rate has been studied. A relative content of young erythrocytes was shown to be higher in cerebral arterial than in peripheral blood. Such distribution is believed to be physiologically important, as young erythrocytes are capable of more effective oxygen exchange for carbon dioxide.