[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.