[Dyspnea. II. Clinical and treatment problems].

In a previous paper (Balanova, Surcheva and Ichev, 2001) we have proposed a scheme about pathophysiological mechanisms involved in dyspnea. Some of the clinical problems in dyspnea were discussed in this paper on the base of that scheme, as well as clinical observations on the patients with dyspnea. Two groups of symptoms were considered--subjective and objective, and their significance for the diagnosis of the dyspnea and of the disease that provokes dyspnea were evaluated.

[Dyspnea. I. Definition and pathophysiological problems].

An analytical review was made on the pathophysiological mechanisms suspected to be involved in dyspnea, accepting that the sensation of shortness of breathing, and the subjective signs (exertion, anxiety and fear) are essential for the diagnosis of this condition. Bearing in mind the anatomical relations in the central nervous system between the structures involved in the control and regulation of the respiration, and these involved in the emotions, a scheme was presented of the pathophysiological mechanisms, which determine the essential signs of the dyspnea. Three neuronal circuits were assumed for the explanation of the manifestations in dyspnea: subjective signs, symptoms of the thoraco-pulmonary and cardio-vascular systems, and these of the voluntary muscular system that accompanied dyspnea.

Changes in the neuronal plasma membrane during synaptogenesis.

During synaptogenesis the plasma membrane of neurons undergoes considerable changes and large portions of it develop to synaptic membranes. This transformation is brought about by biochemical and morphological changes. The aim of the present investigation was to study by morphological methods the in vivo changes of some basic components of the neuronal membranes during the early postnatal period, when active synaptogenesis occurs.

Light and electron microscopic demonstration of cholesterol distribution in membrane structures of the rat auditory cortex.

As part of our investigations on the changes in the cortex of different stages of ontogeny, the aim of this study was to analyse the cholesterol distribution in the auditory cortex of adult rats. The light microscopic Schultz reaction as well as electron microscopic thin sections and freeze-etching combined with a cholesterol specific marker were applied to cholesterol demonstration. High and low cholesterol areas were found in the plasma membrane and membranes of some organelles.

A freeze-etch study of the central myelin.

The intramembranous organization of the interparanodal myelin lamellae in CNS was investigated by means of the freeze-etching technique. The density of the IMPs is about equal on both P- and E-fracture faces of every myelin sheath but varies between the myelin sheaths. The morphology of the myelin tight junctions was also described.

[The morphology of the glial cells in the inferior olivary complex of ground squirrels (Citellus citellus L.). I. Oligodendrocytes].

The morphological characteristics of oligodendrocytes in the lower olivary complex of ground squirrels at various ages were studied by light and electron microscopes. On the basis of an analysis on thick sections, stained with toluidine blue, it was established that nuclei of these cells were smaller and darker in comparison with those of astrocytes. The mean oligodendrocytes, located in perineuronal, perifascicular, perineuronal-perifascicular, interfascicular, perivascular position or freely situated, predominated in the neuropile of the lower olivary complex.

[Cytochemical localization of concanavalin A binding sites in the peripheral nerve axons of old rats].

Distribution of alpha-D-mannose and alpha-D-glucose residues of glycoconjugates in axons of sciatic nerves of 24-month old rats of Wistar strains was studied by concanavalin-A-ferritin conjugate. In some of axons there were cumulations of ferritin molecules in agglomerates of various size with polarization of the phenomenon at preserved integrity of myelin sheath. In other cases the concentration of a large number of lectin binding sites was established in the region of the degenerating part of myelin sheath, engrossed in the axon cylinder.

[Changes in the actin distribution in the neurons of the cerebral cortex in newborn, adult and old rats].

The distribution of actin in neurons of sensorimotor cortex of newborn, 3-month- and 12-old-month old rats was studied by an immunohistochemical method. There was a diffuse staining of perikarya [correction of perikaryocytes] in contrast to the mature 3-month-old rats in which immunopositive material was located mainly at the periphery of neuronal bodies. A diffuse immunostaining was established in some nerve cells of the elderly 12-month-old rats.

Localization of concanavalin A--binding sites on neuroepithelial cells in early newt's neurula after treatment with noradrenalin.

The concanavalin A (Con A)--binding sites on the cell surface of newt's neural plate and groove in norm and following treatment with noradrenaline (NA) were examined ultrastructurally. The changes in the distribution of Con A--binding sites as well as structural changes of endocytic vacuoles in experimental conditions were described. The present results suggest that the differences in the Con A--binding were caused by receptor interaction of the plasma membrane glycoconjugates and the applied neurotransmitter.

[Free postsynaptic-like compactions in the inferior olivary complex of the suslik (Citellus citellus L.)].

The morphological peculiarities of the neuropil [correction of neuropapilea] in the inferior olivary complex of young and elderly ground squirrels were studied by and electron microscope during periods of hibernation and waking. In some of the distal and middle dendrites and dendritic spines [correction of prickles] in elderly ground squirrels there were plaques, composed of electron-dense material with structure similar to postsynaptic condensations, but without presynaptic specializations of chemical synapses. The free postsynaptic-like condensations are located usually in dendrites, which fit to the cellular bodies and sprouts of oligodendrocytes, myelin sheath of nerve fibers and more rarely to astrocytes or lamellae and in single cases to neuronal perikaryon.

[Ultrastructural research on the sensorimotor cortex in adult rats. I. Intranuclear inclusions in the neurons and astrocytes].

The morphological peculiarities of neurones and astrocytes in the sensorimotor cortex of mature (over 3 months) and elderly (over 24 months) rats were studied at electron microscopic level. Intranuclear inclusions are found in the nuclei of pyramidal neurones from the third and fifth layer. On the basis of their fine structure they could be grouped into the following types: 1.

Anionic sites in the myelin sheath as shown by cationized ferritin.

The distribution of anionic sites in the myelin sheath of sciatic nerves of rabbits was studied using cationized ferritin. Ferritin molecules were observed on the cytoplasmic sides of the myelin lamellae stratified in paranodes and Schmidt-Lanterman clefts. In the compact myelin, ferritin molecules have not been found in the tissue sections.

[The ultrastructure of the inferior olivary complex in ground squirrels (Citellus citellus L.). The neuropil. Age-related changes in the axons].

The morphological characteristics of axon terminals among a neuropil in the lower olivary complex of ground squirrels at various ages were studied by an electron microscope. The presynaptic part of the chemical synapses in the glomerular or outside glomerular position among the neuropil pf this nuclear complex were axon terminals and terminals "en passant". These axon elements participate in the formation of crash-like synapses with somatic, dendrite prickles, but also with dendrite adjuncts in the formation of complex synaptic connections.

A freeze-etch study of the central myelin.

The intramembranous organization of the interparanodal myelin lamellae in CNS was investigated by means of the freeze-etching technique. The density of the IMPs is about equal on both P- and E- fracture faces of every myelin sheath, but varies between the myelin sheaths. The morphology of the myelin tight junctions is also described.

Neuronal Na+, K+-ATPase in the peripheral nerve fibers.

ATPase activity was localized by means of Wachstein-Meisel's method in rat sciatic nerve fibers. Using controls with ouabain, the presence of alpha + (neuronal) Na+, K+-ATPase was examined. The enzyme occurs in the ATPase reaction of the myelin-forming membranes, axoplasm and Schwann cell cytoplasm.

Soybean agglutinin-binding sites on the human sperm surface.

Some differences in the distribution of lectin-binding sites on the surface of the plasma membrane of acrosomal and postacrosomal regions and tail of ejaculated human spermatozoa were demonstrated by means of horseradish peroxidase labeled soybean agglutinin. The acrosomal region was more densely coated with labeled lectin in comparison with the postacrosomal region. Hapten inhibition with N-acetyl-D-galactosamine was used as control.

Structure of the plasmalemma of human spermatozoa after treatment with antispermatozoa serum and concanavalin A.

Human ejaculated spermatozoa were treated with antispermatozoa serum as well as with the same serum and concanavalin. A. At both experimental conditions clusters of intramembranous particles both on P-face and on E-face in the acrosomal and postacrosomal regions were seen.

[Morphology of glial cells in the lower olivary complex of the pigeon (Columba livia). II. Oligodendrocytes].

The morphologic peculiarities of oligodendrocytes in the lower olivary complex (LOC) of a pigeon were examined at light and electron microscopy level. The analysis on the basis of the applied histological techniques (staining with cresyl-violet and silver impregnation according to Goldgi-Rio Hortega) showed that oligodendrocytes were small rounded cells with nuclei stained more darkly than those of astrocytes. Oligodendrocytic arborizations were thin, slightly ramified and small in number.

[Morphology of glial cells in the lower olivary complex of the pigeon (Columba livia). I. Astrocytes].

The morphologic peculiarities of astrocytes in the lower olivary complex (LOC of a pigeon were examined at light and electron microscopic level. Usage of histological technique established the presence of three varieties: fibrous, real protoplasmic and covered type of astrocytes. In LOC of a pigeon most of astrocytes, observed by the electron microscope, possessed in their cytoplasm bunches of filaments, which passed and proceeded along side to astrocytic arborizations parallelly.

[Light microscopic and ultrastructural study of the lower olivary complex in the pigeon (Columba livia)].

The normal morphology of neurones and neuropile of the inferior olivary complex (LOC) in a pigeon (Columbia livia) was investigated by a light and electron microscope. The light microscopic analysis on the basis of the histological techniques of Vissl, Gldgi-Rio Hortega showed that olivary neurons had moderate mean dimensions and moderately branched dendrite tree, but single neurons with a model for dendrite branches were encountered similar to the second type of neurons in mammals. Axo-somatic synapses and synapses on the primary dendrites were comparatively small in number, observed by the electron microscope.

[Degenerative changes of the myelin fibers of sciatic nerves in aged rats].

Ischiadic nerves of 24-month old rats were examined by electron-microscopic technique. It was established that a large part of myelin fibres had degenerative changes, manifested at various degree. Axonal cylinder was atrophied even to complete disappearance.

[Immunohistochemical demonstration of changes in the distribution of glial fibrillary acidic proteins of the auditory cortex in aging rats].

Changes in the distribution of glial fibrillary acid protein-positive astrocytes in the auditory cortex of aged rats were investigated by an immunocytochemical method. It was established that there was an increase of these glial cells in all layers of the cortex. Possible causes for these changes are discussed.

[Age changes in the distribution of VIP-positive neurons in the rat auditory cortex].

Using the methods of immunocytochemistry, we made a study on VIP-ergic neurons in the auditory cortex of young and aged rats. Comparing the results we observed considerable diminution in the number of VIP-positive neurons of aged animals in all cortical layers.

[Changes in the distribution of negatively charged sites of the synaptosomal membrane in adult rats].

Changes in the distribution of Anionic sites on the synaptosomal membrane of old rats were investigated by means of cationized ferritin. Synaptosomal fraction was isolated from the cerebral cortex of two groups of rats: a control group-rats aged 2 months and second group-rats aged 14 months. Some diminishing of density was established on anionic sites as well grouping in larger or smaller aggregates of the same sites on the membrane of some synaptosomes of old rats.