Gegužis, Vytautas

Currently, the histochemical reaction for acetylcholinesterase (AChE) remains the most feasible and reliable technique to visualize intrinsic neural nerves and ganglia both in the heart as well as in other internal organs, independently from animal species. It is suspected that AChE is not a specific cholinergic marker and it locates at non-cholinergic neurons and nerve fibers as well. In order to examine which types of nerve fibers and ganglion cells maybe visualized by the histochemical method for AChE according to Karnovsky-Roots protocol (1964), special technique of the immunofluorescence labeling for choline acetyltransferase (AChE) and thyrosine hydroxylase (TH) before and/or after histochemical reaction in Karnovsky-Roots medium was developed and evaluated on both the heart wall and the large bowel sections of the human and few mammalian species. The study results demonstrate that the distributions of AChE, ChAT and TH coincident entirely in neural tissues of the examined organs, but the ChAT immunoreactive mucous epithelial cells do not exhibit the AChE in the large bowel. [...].

The autonomic cardiac nervous system plays a crucial role in the fast control of heart rate, contractility and tone of the coronary vessels. Although structural organization of intrinsic cardiac nervous system (ICNS) in the human as well as in some other mammals has been previously described in detail, the relationship of extrinsic cardiac nerves with epicardiac ganglionated nerve plexus (EGNP) has not been in a scope of special investigation so far. [...]

According to EU norms for workplace air (DIN EN 689: 1994-04-E), no inhalation of dangerous vapours from chemical agents utilizing routinely for embalming of organs and corpses in the human anatomy is allowed. Therefore, a formalin-free preservation of the human organs and total corpses for anatomical dissertation has been launched in Kaunas University of Medicine since 2007. The aim of the study is to prospect a suitability of the commercially available FineFix fixative for preservation of dissecting material in laboratories of study of the human anatomy.

Since the distribution of sympathetic and vagal efferent nerve fibers within the mammalian epicardial ganglionated nerve plexus (EGNP) is unknown, the present study was aimed to identify the access sites and course of sympathetic and parasympathetic nerve fibers within the canine and mouse EGNP. Methods. EGNP was immunohistochemically revealed by a multiple labeling of nerve fibers positive for choline acetyltransferase (ChAT) and tyrosine hydroxylase (TH) on the mouse whole-mount hearts and on cryo-sections of the canine hearts. [...]

Aktualumas. Skilvelių pertvaros defektas, atsiradęs ūminio miokardo metu, labai sunkina ligonio būklę. Medikamentinis gydymas mažai veiksmingas ir daugelis ligonių miršta. Chirurginis gydymas, uždarant plyšusią skilvelių pertvaros dalį, gali išgelbėti ligonio gyvybę, nors šis gydymo metodas yra sudėtingas. [...].

In respect of further investigation of the ovine model, a stereomicroscopic study of the ovine extrinsic cardiac nerve plexus was performed in order to identify the relationship of the epicardial ganglionated nerve plexus (EGNP) with sympathetic chains and vagal nerves. EGNP was revealed by a histochemical method for acetylcholinesterase on whole heart while extrinsic cardiac nerves were stereomicroscopically tracked using a microdissection of 18 newborn German black-faced lambs. The present study shows that the dorsal and ventral right atrial, and the middle epicardial nerve subplexuses received the extrinsic neural input from the right cervicothoracic (stellate) and the right thoracic T2, T3 ganglia of the sympathetic chain as well as from the right vagus nerve. The lamb left dorsal epicardial nerve subplexus is supplied by extrinsic nerves from the left thoracic (T5, T6) sympathetic ganglia and the left vagus nerve. The cardiac branches from the both vagal nerves, both stellate ganglia, left superior cervical and left middle cervical ganglia proceed into the left and right coronary epicardial nerve subplexuses. The sources of neural inputs as well as the course of extrinsic cardiac nerves into the ovine heart are sharply distinct compared to schema of the human heart innervation.

In neonates and infants, the intrinsic neural pathways are considered to be important for radiofrequency ablation that is indicated in cases of incessant supraventricular and atrioventricular nodal re-entry tachycardia. The anatomy of epicardiac neural plexus in the human fetus, unfortunately, has not been in a scope of special investigation so far. The aim of the present study was to determine the anatomy of intrinsic cardiac ganglia in respect of the epicardiac nerve plexus in the human fetuses at different gestation stages. Twenty-one fetal hearts were investigated applying a technique of histochemistry for acetylcholinesterase to visualize the epicardiac neural ganglionated plexus with its subsequent examinations on total hearts. Epicardiac neural plexus of fetuses at 15-40 weeks of gestation with numerous (929 ± 62) ganglia might be clearly differentiated into seven ganglionated subplexuses, topography and structural organization of which were typical for adult human heart. Most ganglia were more or less oval in shape, whereas some ganglia had the irregular appearance due to their extensions at the interganglionic nerves. Mean area of fetal ganglia was 0.03 ± 0.008 mm2 and the largest ganglia were mainly concentrated on the dorsal surface of both atria. A direct positive correlation was revealed between the fetal age and the ganglion size (mm2) as well as between the fetal age and the number of interganglionic nerves (p < 0.05). In conclusion, this study demonstrates that the distribution of the epicardiac ganglia in the human fetuses at 15-40 weeks of gestation is not age dependent, but appearance of epicardiac ganglia confirms their prenatal growth and remodeling.