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Biomedical subjects

V N Shvalev

Publications and source records attributed to V N Shvalev.

At least 19 recordsLinked to original sources
PubMed2006

[Distribution of nitric oxide synthase in human intracardiac ganglia].

This is the first study to report presence of nitric oxide synthase (NOS) in the human intracardiac nervous cells. By applying immunohistochemical technique it was shown that majority of neuronal perikaryons contain NOS 1 (neuronal NOS). We conclude that in human heart about half of neurons have NO-ergic phenotype. These cells are also cholinergic and related to parasympathetic part of autonomic nervous system. Moreover in human heart NOS contains pericellular baskets that surround intramural neurons. This points to the presence of the enzyme in parasympathetic preganglionic fibers. A substantial differences of patterns of NOS expression in cardiac neural ganglia between humans and experimental animals are discussed.

Adult↗
PubMed2006

[Nitric oxide synthase in human intracardiac ganglia in the normal and ischemic myocardium].

Nitric oxide synthase (NOS) expression in human intracardiac ganglia was studied using two techniques--histochemical demonstration of NADPH-diaphorase and immunohistochemical staining for NOS. To detect the influence of coronary heart disease on NOS expression, hearts were studied in patients that died from heart failure (n = 8) and in persons that died in accidents (n = 3, control). It was found that human intracardiac neurons normally expressed mainly NOS1, and the proportion of these cells amounted to about 40%. A portion of neurons with low and moderate density of staining for NADPH-diaphorase was increased in ischemic myocardium, probably, due NOS2 induction.

Acetylcholinesterase↗
PubMed2005

[Consequences of the saphenous artery denervation under normal and chronically lowered blood pressure in rats].

We studied constrictor responses of saphenous artery after sympathetic denervation in normotensive rats and rats with chronic regional hypotension. Abdominal aorta was partially occluded in Wistar rats distally to the renal arteries, lowering blood pressure in the hindquarters by about 40%, a week later to denervate saphenous artery the femoral nerve was cut. The density of periarterial nerve plexus and neurogenic responses of the vessel restored partially in 2 weeks and completely in 6 weeks after the surgery; the chronic hypotension did not modify the dynamics of reinnervation. Arteries of both groups of rats demonstrated higher sensitivity to noradrenaline during 6 weeks after denervation, whereas vessel sensitivity to serotonin was enhanced only in normotensive rats. Therefore, chronic hypotension may prevent postdenervation hypersensitivity of vascular smooth muscle to vasoconstrictors.

Animals↗
PubMed2004

[Neurotransmitter stage in the development of peripheral part of autonomic nervous system].

The dynamics of neurotransmitter stage in the development of autonomic nervous system (ANS) was studied in rats starting from the moment of initial appearance of neurotransmitters acetylcholine and adrenalin in ANS peripheral part main nervous plexuses. Cryostat sections of embryos on developmental days 13.5, 16.5 and 18.5 and of neonatal rats aged 0.5 and 1.5 days were treated with glyoxilic acid, using Karnovsky-Roots method and impregnated with silver nitrate according to Bielschowsky-Gross method. Acetylcholinesterase in vagus and in spinal ganglia was found on day 13.5, while catecholamine in sympathetic trunc was detected in animals immediately after the birth. Periods of the beginning of neurotransmitter stage in ANS development in rat and man were compared and it was established that it was delayed in rat as in immature-born animal.

Acetylcholine↗
PubMed2003

[Morphological and morphometrical changes in nervous apparatus of the adrenal medulla after sudden death of patients with various cardiac pathology].

Adrenal glands were studied at early autopsy of 28 men aged 35-60 years after their sudden cardiac death. According to the presence and character of pathologic manifestations detected in myocardium, three groups of cases were distinguished: group 1 (control) included the people without myocardial pathology (traffic accident victims), group 2 consisted of the patients with ischemic heart disease (IHD) in association with recent myocardial infarction, group 3 included the patients with IHD and hypertension. The study was performed using the methods of silver impregnation of nerve terminals and planimetric point-counting method. Analysis of density of distribution of nerve plexuses in adrenal medulla in the groups studied has shown a tendency towards its reduction in group 2 and a significant decrease in group 3. Reactive-degenerative changes in the nervous structures of adrenal medulla were detected in these two groups, while in group 3 these were accompanied by the compensatory-adaptive changes in glandular nervous apparatus. However, despite the pronounced changes found in the nervous structures of adrenal medulla, their function remained high enough, that could be explained by a transition from nervous control of adrenal activity to a humoral one.

Adrenal Medulla↗
PubMed2001

[Organization of spinal subpial plexus in man and various animals].

By means of silver nitrate impregnation and luminescent method adrenergic nervous plexuses in spinal cord of 7 people, 6 dogs, 4 cows and 7 rabbits was studied. 17 serial slices of human and rabbit embryos were also examined. Numerous branching and brightly luminescent adrenergic nerve endings were discovered in composition of nervous plexus of spinal cord subpial layer in man and in animals. They should be thought of as sympathetic endings exerting adaptational and trophic influence on adjacent structures and partly penetrating substantia alba of the spinal cord. These observations broaden the existing conceptions on receptory and effectory neuronal processes on the spinal cord surface.

Animals↗
PubMed1997

[Interneuronal interrelationships in autonomic ganglia (the ultrastructural aspects)].

Ultrastructural and immunocytochemical results of studies on interneuronal relationship in vegetative ganglia were represented. Age-related changes of synapses (appearance of synaptic type vesicles and smooth endoplasmic reticulum cisterns in postsynaptic terminals), peculiarities of interneuronal links in neurons containing neuropeptide Y and NO-synthase and structural manifestations of non-synaptic interneuronal links were shown. Modern views on interneuronal communications were discussed.

Aging↗
PubMed1996

[The structure of the stellate sympathetic ganglia under long-term hypoxia].

Changes of mitochondrial ultrastructure indicating not only degenerative processes but also the presence of organelle adaptive reactions were demonstrated in sympathetic neurons. Appearance of osmiophilic inclusions in mitochondrial matrix relates to most typical organelle alterations in ageing. Number of smooth endoplasmic reticulum vesicles equal in size to synaptic vesicles of nerve cells processes grows higher. Such vesicles are usually located near postsynaptic active zones and areas with neuronal plasmolemma free from glia. Their outward resemblance does not allow to claim that neuromediators and neuromodulators may turn up in these vesicles, although dendrites contain and may release certain biologically active substances. Basic difference between 24 and 30-months old rats lies in earlier degenerations of nerve cells in old animals. Forming of dark granules may be also associated with conditions of fixation. Small granular (SG) cells lacked typical lipofuscine granules, while their ultrastructure changed insignificantly. SG cells capacity to divide mitotically in functional maturity is likely to be one of the possible explanations of such difference.

Aging↗
PubMed1996

[The phenomenon of focal sympathetic denervation of the major vessels in the development of atherosclerosis].

22 aortas obtained from people aged 20-55 who died in accidents by early dissections were studied. Adrenergic nerve plexuses of aortal wall were examined by quantitative neurohistochemical method. Focal reduction of indexes of these plexuses density was defined by the age of 30. The process of desympathization runs unevenly with nerve plexuses from zones of aorta cranial to areas of its branching altered to greater extent. This very zones are subjected to atherosclerosis selectively. We tend to consider the process of desympathization for one of atherosclerosis factors developing in vascular wall zones with the loss of adaptive-trophic influence of the vegetative nervous system sympathetic activity.

Adult↗
PubMed1994

Inclusions similar to Hirano bodies in urinary bladder neurons of dogs.

Unusual intracytoplasmatic inclusions were found in urinary bladder neurons in dogs. The plate-like inclusions were composed of thin filaments, and when viewed en face, appeared as oval or angular bodies with regular lattice work array. When viewed in a transverse section, they were of rod-like shape and were composed of longitudinal filaments and transverse bars. The inclusions were observed in all ganglia of the urinary bladders studied. Three-dimensional reconstruction of the inclusions was made, using a tilting device. By means of this reconstruction, it could be demonstrated that their ultrastructure is similar to that of Hirano bodies which occur in human neurons of the central nervous system in cases of neurodegenerative diseases. The authors suggest that unusual intraneuronal inclusions represent a peculiarity in cytoskeletal protein assembly typical of canine urinary bladder neurons.

Animals↗
PubMed1993

Intracellular penetration of ruthenium red in embryonic nervous tissue.

Electron microscopic investigations, using ruthenium red revealed that dye is usually observed in immature neuronal cells in autonomic ganglia of rat embryos and fetuses. Ruthenium red does not penetrate undamaged neurons in mature ganglia. Ruthenium red positive material covers neuronal cell plasmalemma even in early primordial phases of autonomic ganglia. Plasmalemma of growth zones does not react with ruthenium red. Intracellular penetration of immature neurons by ruthenium red, according to expectation, depends on damage to cell membrane due to the fixation procedure, especially in the growth zones.

Animals↗
PubMed1992

[The ultrastructure of human intracardiac neuroganglia].

Light and electron microscopic studies of nervous ganglia of the sinoauricular area of the heart were performed in 7 people dead at the age from 23 to 58 years (44 +/- 6) from not cardiac causes. The ganglia were disposed under the epicardium and had from 1 to 17 neurons as well as bundles of myelinated (MNF) and nonmyelinated nerve fibers (NNF). The ganglia most often had light neurons with a rounded nucleus and a compact nucleolus, with invariable cisterns of the granular endoplasmic reticulum microfilaments, electron-dense bodies, lipofuscin granules and edematous mitochondria. More rare were dark neurons with osmiophilic cytoplasm and nucleus of an irregular shape. Most NNF and MNF in the ganglia had normal ultrastructure. In part of NNF and MNF there were edemas of axis cylinders, fragmentation of neurofilaments and microtubules, sometimes MNF with transverse and longitudinal cleavage of myelin were seen. The significance of influences of the age, intravital pathology and postmortem alterations on the ultrastructure of intracardiac nervous ganglia of man is discussed.

Adult↗
PubMed1992

Neurohistochemical and electron microscopic investigations of pathological and age-related changes in the cardiovascular system.

Neurohistochemical and electron microscopic investigations of the autonomic nervous system (ANS) of man and animals suggest that its ontogenesis can be divided into the premediatory, mediatory and postmediatory periods of development. The postmediatory period begins heterochronically in various ganglia of the ANS. A normal process of early cardiac desympathization usually occurs at the age of 35 to 60 years. Specific changes of preceding sudden cardiac death are elicited in different parts of the ANS and adrenal glands. This is accompanied by focal myocardial desympathization. Coronary vessels and conducting system which may influence myocardial hypersensitivity zones to catecholamines are involved in the process of destabilization of the cardiac function. Moreover, relationships are demonstrated which exist between the atherosclerotic lesions of the aortic wall and the status of its nerve plexuses.

Adult↗
PubMed1991

Immunohistochemical investigation of autoantibodies to nerve fibers in cardiomyopathy.

The immunofluorescence technique was used to trace auto-antibodies to neural structures in the blood serum of 180 patients with various cardiomyopathies and 20 healthy probands (controls). Incubation of cryostat slices of heart, kidney, spinal cord and medulla oblongata of Wistar-rats or of cell cultures of embryonal spinal cord with the blood serum of patients with cardiomyopathies resulted in immunofluorescence of nerve fibres and neuronal perikaryon. The controls were negative. The question remained unanswered for the nature of the involved antigen. Neurohistochemical findings suggested auto-antibodies in sera of patients to be orientated to cholinergic endings. The authors suggest the immunomorphological approach as practicable for revealing auto-antibodies in neurohistological studies.

Animals↗
PubMed1990

[Ultrastructure of neurons of the human sympathetic ganglia after sudden death (morphometric study)].

Six cases of urgent autopsies after a sudden cardiac death (SCD) of persons at the age 40-60 years and 5 control cases have been investigated. Osmiophilic mitochondria with inclusions make 1% of the whole neuronal cytoplasm volume. If we take all mitochondria as 100%, volumetric density of mitochondria with osmiophilic inclusions makes 9.6%. Volumetric density of mitochondria at SCD in comparison with the control is significantly higher in connection with increase of their size. In other components of cytoplasm, in particular in lysosomes and lipofuscin, no changes are revealed.

Adult↗
PubMed1989

Electron microscopic study of cardiac ganglia in human fetuses.

The early events in the development of the heart ganglia and nerves in human fetuses ranging from 5 to 12 weeks of gestation age were studied by transmission electron microscopy. The first neuroblasts in the atrial mesenchyme differ from surrounding cells in the presence of short cisternae of rough endoplasmic reticulum and in the absence of glycogen particles. The most valuable criterion for identification of neuroblasts is the presence of contacts with preganglionic nerve terminals. Only ganglia composed of compact aggregations of neuronal cells and nerve terminals have a complete glial sheath. The first signs of synapse formation were seen in 5-week-old fetuses; well developed synapses with many synaptic vesicles were found from the 8th week of gestation onwards. These were predominantly axodendritic synapses. It is proposed that synaptogenesis begins with the appearance of osmiophilic zones at the sites of interneuronal contacts, then synaptic vesicles move by axonal transport to reach the preformed specialized junctions and stop in axonal presynaptic varicosities.

Autonomic Fibers, Preganglionic↗