Fine structure and seasonal changes in the constant electrical field in man

Fine structure of distribution of electric potential difference (EPD) in human skin of some points on arms, body and face relative to a referent point on the neck was investigated. Diurnal variations of EPD fine structure for individuals and seasonal differences expressed in an increase of the amplitude of variations and shift of EPD mean values to the positive region in winter as compared with summer were observed. The indicated peculiarities are connected with external factors and reflect changes of metabolic activity of organism living activity processes.     

Manifestations of the mobility of sensory neurons of the spinal ganglion after stimulation of its peripheral receptors

The body of sensory neurons in the frog spinal ganglion++ possesses an active mobility. This is demonstrated as pulsation and changes in its form. The mobility is closely connected with electrogenesis of cells. When an irritation is applied (press of a needle, or application of acetylcholine on the urinary bladder receptors), the neurons of the node respond with an increasing rate of impulse activity. Simultaneously, the mobility of these neurons increases. The character and form of their mobility in response to mechano- and chemoirritation differ from each other. Possible mechanisms of connection between the form of the cell body mobility and the character (active or passive) of its electrogenesis are considered. The mobility of the neurons, together with other morphological signs (tinctorial peculiarities and some others) can serve as an indication of their functional state without application of electrodes in morphological experiments.     

Natural killers and biogenic amines: the paracrine regulation in the immune system

Natural killers are referred to the category of cells well known for their assistance in cyto-differentiation control. Mechanisms of such assistance include cytolytic and secretory effects on the target. In this aspect, the NK capacity to assist in local aminoregulatory processes by adrenalin, serotonin, histamine release contained in these cells granules is considered to be the least studied and the most problematic issue. The solution of this problem demands taking into consideration a number of conditions: the NK ability to receipt biogenic amines and peculiarities of receptor structure; principal differences in mechanism of action of biogenic amines which enter the cell through exogenous pathway or which are synthesized endogenously; correlation between biogenic amines presence in the granules and functional NK state. Hypothesis of generation connected with the problem suggests the NK assistance in cytolysis in concomitant mechanisms of paracrine regulation of cellular microenvironmental proliferative response, induction of local inflammatory and immunomodulating processes.     

Age-dependent cadmium accumulation in organs of intoxicated rats and changes of indices of acid-base balance of blood in different conditions of antioxidant defence

Age peculiarities of cadmium cumulation in the organs of rats under different conditions of antioxidants administration. Considerable hepato- and nefrotoxic effect of the given xenobiotic under different conditions of its supply into the organism was revealed. The strongly pronounced differences between the age distribution of cadmium in the organisms have been marked. It is proved that the most antioxidantal activity is shown by sodium selenite when administered into the organism before poisoning with cadmium. It is stated that the indices showing the acid-alkaline state are subject to the greatest changes in the bodies of young animals. In this case they have more expressed toxic effects under the influence of ions of heavy metals as well as the receptivity to the positive influence of antioxidants.     

Cellular mechanisms of the development of primary arterial hypertension

Modern views on the contraction and dilatation mechanisms of vessel smooth muscle cells are discussed. The data on main role of the cation-transport cell system function peculiarities in the primary arterial hypertension genesis, a relation cell hyperreactivity to those peculiarities and its genetical origin, are reported. It is supposed that the hereditary predisposition forms certain functional lability of cellular elements in different organism tissues, and, in consequence of that, the environmental influences can provoke the development of primary arterial hypertension.     

Features of the structure of arteries of the lower extremities in man

A comparative investigation has been performed on structural peculiarities of muscle arteries having various caliber in the lower extremities and in the anterior thoracic wall (section material, 40 observations). An essential predominance of the muscle tunic thickness and deterioration of blood supply has been stated in the arterial wall and in the distal parts of the lower extremities. The structural peculiarities revealed in the arteries of the extremities are connected with functional conditions of blood supply in the zone at the vertical position of the human body (orthostatic arterial hypertension).     

Reactions of cellular structures of the brain of laboratory animals in oxygen deficiency

Analysis of the latest literature data and the authors' neuromorphological observations give the possibility to consider that structural reactions of the cerebral cellular elements of higher animals to oxygen insufficiency have a common base, but vary in dependence of the hypoxia form and the character of its influence and peculiarities of individual reactivity of the organism. Neurons and gliocytes possess rather effective mechanisms of resistance to hypoxia and ischemia, and are connected with intracellular regenerative and adaptive-compensatory processes. Hypoxic factor of pathogenesis of dystrophic-destructive changes in the cerebral cells is, however, subcoordinative, but not self-sufficing in all cases without any exception. Hypoxic and intoxicational lesions of the brain may have an independent cytological expression, despite the fact that differentiation of the combined signs is usually difficult.     

Isoenzymes of blood serum alkaline phosphatase under experimental cholemia

The activity and isoenzymic spectrum of alkaline phosphatase of the blood serum and liver under cholemia caused by deoxycholic acid were compared in healthy animals and in animals with the affected liver. It is shown, that under conditions of the bile acids higher content in the organism due to deoxycholic acid, the total activity increases considerably and there appears an isoenzyme absent in the blood serum of healthy animals. Changes in the activity and isoenzymic spectrum of alkaline phosphatase under experimental cholemia developing against a background of the healthy and affected liver are characterized by certain peculiarities.     

The systems organization of human functions: the theoretical aspects

On the basis of the theory of functional systems, suggested by P. K. Anokhin, leading principals of system organization of human functions are regarded. General characteristics of functional systems are stated. Some peculiarities of intrasystem and intersystem organization of functional systems of human organism are discovered. The role of functional systems in organization of normal human live activity as well as under psychoemotional stress and pathology is shown. System principals of compensation of disordered functions during rehabilitation of persons undergone stresses and ecologically unfavorable loads are considered.     

Various types of non-synaptic intercellular contacts in the developing brain of the rat

Peculiarities of ultrastructural organization and localization of early forms of avascular nonsynaptic types of junctions formed in 14-18-day-old rat embryos have been studied; cerebral structures different in their phylogenic relations (the sensomotor cortex and nucleus caudatus) are taken as an example. Five main types of nonsynaptic intercellular junctions have been revealed: desmosome-like, gap, symmetric, asymmetric and mixed junctions. They differ by their ultrastructural organization. These types of junctions make the main types of contacts: soma-somatic, dendro-somatic, dendro-dendritic, axo-somatic, axo-dendritic. Desmosomes form the greatest number of the contacts. The earliest and the most primitive are gap junctions; they, evidently, reflect functional activity of desmosome-like junctions. The mixed junctions, perhaps, reflect the developmental stages of the intercellular contacts of transition from one type of junctions into another. Localization peculiarities of the nonsynaptic intercellular contacts are demonstrated: glomerule-like formations, establishment of numerous contacts looking like a successive chain, and so on. For some other indices a longer period of intercellular contact formation in the nucleus caudatus is noted, comparing the sensomotor cortex, though the latter is a newer structural cerebral formation from the phylogenic point of view.     

Age variations in ethylmorphine demethylase and benzopyrene hydroxylase activities in rat liver microsomes

The ethylmorphine demethylase activity of the rat liver microsomes was higher in three-month animals (as compared to one-month), remained at a high level in the 12-month and decreased in old rats. The benzopyrene hydrolase activity increased in three-month animals, decreased in 12-month rats and remained the same with subsequent ageing of the organism. Asynchronicity of variations in the oxidation rate of different xenobiotics with ageing is considered as a result of changes in substrate specificity of the monooxygenase system due to metabolic peculiarities which reflect the age development of the organism and extinction of the reproduction function.     

Axospinal synapses in the forebrain cortex of aquatic and terrestrial turtles

An electron microscopical investigation of synaptic organization of the superficial plexiform layer of three forebrain cortical zones (hippocampal, dorsal and piriform) in two aquatic and two land Chelonia species has been performed. As demonstrate the data obtained and those from the literature, the main elements of the axo-spinal complexes (spines--synapses--neural terminals) possess both stability properties, contributing to structural firmness of the contacts and their reliability during activities, and plastisity ensuring the maintenance of dynamic equilibrium and a possibility for adequate rearrangements. Under normal conditions, the functional shifts in ultrastructure of the synaptic apparatuses are, possibly, so negligible that they cannot mask certain specific fractures of the synaptic organization of the neural centers. When comparing structures of the axo-spinal complexes in functionally dissimilar cortical zones, more constant, common for all species of Chelonia studied signs are definitely revealed. They characterize a certain level of the neural processes integration. There are signs more variable, evidently, ensuring adaptive rearrangements within limits of the given level of the interneuronal connections organization which can be considered as ecological and species-specific peculiarities.     

Ultrastructural features of hormone-producing cardiomyocytes under certain experimental and clinical conditions

Ultrastructural peculiarities of the cardiac hormone secretion (atrial natriiuretic factor) have been studied under certain experimental and clinical conditions. In atrial myocytes of intact dogs degree of the Golgi complex development, where the hormone is formed, amount of endocrinic granules and their qualitative composition vary considerably even in neighbouring cells. These structures reach a very great development in myocytes of the left atrium in persons with mitral stenosis, where certain anomaleously large secretory granules, resembling lyosomes are formed. When the organism is cooled up to 27-28 degrees C and the blood stream is interrupted in the experiment and along the course of a defect correction, amount of the secretory granules in cardiomyocytes decline significantly. The Golgi complex decreases, its cysterns become fragmented, their content is cleared. After warming up to the normal temperature there is no complete restoration of these structures. On the 3d day after the experiment in some cases signs of hypertrophy and elevated functional activity of the secretory structures appear. The ways of synthesis, accumulation and degradation of secretory granules in cardiomyocytes are followed, a classification of their ultrastructural varieties is suggested: forming, young, mature and dissolving forms. Together with the analysis of the Golgi complex, it helps to judge the endocrinic activity of cardiomyocytes.     

Functional structure and cerebrovascular circulation of the vestibulo-ocular formations of the brain stem of the human cerebrum

This work is dedicated to the study of anatomo-physiological peculiarities of the construction and cerebrovascular circulation of the vestibulo-ocular formations of the brain stem of the human cerebrum. The analysis of anatomo-physiological data enable to convince that the arches of the vertical and horizontal vestibulo-ocular reflexes include many structures of the brain stem of the human cerebrum, which are located along its longitude from the superior colliculi to caudal sections of brain stem. There is an existence of separate mechanisms of horizontal and vertical vestibulo-ocular interaction. The peculiarity of cerebrovascular circulation of main vestibulo-ocular structures is their profuse vascularisation chiefly by branches of the vertebro basilar system of arteries, which widely connected between each other, providing sufficiently profuse circulation in normal conditions of vital activity. The anatomical information above has great importance for the correct interpretation of the symptoms of infarctions in vertebro-basilar pool of the cerebrum, diagnostics and expert appreciation of these pathological states.     

Nonlinear analysis of the dynamics of the human balance control system during fixation and smooth pursuit of visual target

The similarity between the dynamics of the human balance control system in the frontal and sagittal planes during the fixation of visual stimulus and smooth pursuit of its sinusoidal movements in the horizontal plane with a frequency of 0.1 or 0.01 Hz (so-named fast and slow pursuit) has been investigated by the nonlinear method of analysis. The experiments were carried out according to the notion that it is possible to describe the process of orthograde standing by a two-segment model--upper and lower segments which are connected by a hip joint (other joints were fixed). It was shown that during fixation the similarity between the dynamics of orthostatic control system in the frontal plane is higher than in the sagittal plane. A slow pursuit does not influence the similarity, but a fast one decreases the similarity in the frontal plane. The indices of similarity between the dynamics of the system in the sagittal plane for all the conditions are close and do not differ significantly. The changes in similarity during fast pursuit are supposed to be connected with the different inertia of eyes and body movements. The differences between dynamic similarity in the frontal and sagittal planes are probably connected with the peculiarities of both balance control during joint fixation and AP-ML control (Winter et al., 1993) under conditions investigated.     

Histological characteristics of the reactions of cerebral neuroglia in laboratory animals

Literature data and the authors' results, concerning structural and functional peculiarities of all varieties of the cerebral neuroglia under effect of a cranial-cerebral trauma, neurotropic chemical products and oxygen insufficiency have been considered. Ideas that neuroglial reactions under the conditions mentioned are proved to be constant and in dependence of certain peculiarities of each case are either progressive or regressive. The reaction degree is mainly proportional to the disturbance power. Nevertheless, certain discrepancies (ariactivity including) can be observed; this is also determined by a combination of prerequisites and by a peculiarity of individual reactivity of the CNS. The greatest stability of astroglia has been stated. Possible variations in relation between changes of neurons and gliocytes are mentioned. Suggestions are made that diffuse-focal progressive reactions of macroglia under conditions of neurotoxicoses can be determined not by proliferation of cells, but by their migration.     

Interpopulation morphological variability of the viviparous pipefish Syngnathus acusimilis Günther, 1873 (Teleostei: Syngnathidae)

In viviparous fish, as is illustrated by the example of the pipefish Syngnathus acusimilis (Syngnathidae), unlike fish that spawn their eggs into the environment, there are virtually no differences between populations in meristic characters, which are formed during the embryonic and larval development. The absence of these differences is due to the stability of conditions, specifically temperature, during the egg incubation in the parental organism. The insignificant differences in the external morphology of the pipefish can also be associated with the presence of the bony plates that completely cover the fish body. The peculiarities of the structure and reproductive biology are not conducive to the ecological and geographical intraspecific differentiation of this fish.     

Cerebellum and organization of behavior: A comparative-physiological aspect

The ontophylogenetic analysis of morphofunctional peculiarities of the cerebellum shows its extremely high adaptability to the requirements for the organization of the nervous activity of the organism corresponding to the level of its evolutionary development and ecological habitat conditions. The changes of the cerebellum in the course of its onto- and phylogenetic development appear to be more pronounced as compared with other cerebral regions. Depending on the level of the development, revealed are different aspects of the cerebellar integrative activity which contributed, if necessary, a quite new directions of the nervous activity, such as learning and cognition, which demonstrates astonishingly wide limits of the adaptability. This explains that the cerebellum in various vertebrates is considerably different by its shape, location of neurons in the cerebellar cortex, and the main peculiarities of afferent, internal, and efferent pathways. There is a reason to suggest that the future study of these aspects of the cerebellar activity will bring us to a clearer understanding of the cerebellar mechanisms of learning.     

Modularity and heterochronies in the evolution of metazoa: Paleontological aspect

All organisms are formed of more or less independent elements, modules. Paleontology deals with morphological modules preserved in the fossil state and allows their evolution within taxa of different levels to be reconstructed. Modularity provides organisms with the ability to evolve, since changes in one module does not influence others, nor disturb the integrity of organism. Each organism may have unique modules represented by a single copy and serial modules developing according to a certain symmetry type. Serial terminal growth is characteristic of ambulacra of echinoderms, in which it is combined with alternating appearance of structures on the right and left of the symmetry plane. The morphology of the solute Maennilia estonica, which has been investigated in detail, shows that the growth model for the brachiola is similar to the model for ambulacra of sea urchins, but without an ocular plate. Probably, the hydrocoel initially induced the appearance of a skeleton necessary for its activity and organized its development according to its own model of terminal growth. Subsequently, the axial skeleton appearing following this pattern could have organized the growth of adjacent parts of the extraxial skeleton following the same model to form a united module. The fusion of modules could have resulted from heterochronies. Extant and extinct material connected with the change in the anteroposterior axis in evolutionary and ontogenetic development of echinoderms provides a prominent example of heterochronies. Heterochronies were the mechanism connecting characters into an integrated ensemble of the body plan. Archaic diversity reflects an attempt to create a new body plan. Various manifestations of archaic diversity show that the emergence of a new higher taxon is connected with the combination of a number of characters united in an integrated complex forming the body plan which is stable from the moment of appearance due to strict recursive relationships between its modules rather than with the acquisition of an individual character, even if it is very important.