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E Repciuc

Publications and source records attributed to E Repciuc.

At least 19 recordsLinked to original sources
PubMed1980

[Synaptoarchitectonic structure of muscles as a synchronizing apparatus for muscle contraction].

Synaptoarchitecture is a new notion, refering to the spatial distribution of motor and plates, to the shape of these synapses and to the last ramifications of motor were fibers. In muscles of the rats limbs, endplates are forming a small strip almost perpendicularly to the main direction of muscle fibers. But in sphincters and in orbicular muscles end plates are randomly distributed. The spatial distributions of end plates in muscles of the limbs build up a synchronizer for simultaneous contraction of all fibers in a given muscle. However in some few muscles of the rat, as are the m. sartorius, m. gracilis and mm. glutei, there are many strips, corresponding to the composite structure of these muscles. A composite structure is one which fibers are not only attached to a tendon, but also to other fibers in the midst of the muscle, without any tendon. It is possible to synchronize even a composite structure, if all synapses are properly located, the end plates being all at the same distance from the farthest insertion. In some rodents, lagomorphs and carnivores almost all muscles are composite. Consequently they are all of the disperse type. There is a bunivoque correspondence between the composite structure and the disperse type of innvervation. The shape of motor end plates is changeable under various pathological and physiological circumstances. Beside the common form, there are "myoid" synapses, as may be encountered in myasthenia gravis, in intensive corticotherapy and in the sphincter ani externus. Myoid synapses are of several sorts: elongated, multipartite and minute synapses. For explanation of these various shapes a hypothesis is put forward, concerning structural changes in the postsynaptic membrane. Finally nervous fibers are so located, as to permit the follow up of the pertinent motor endplate, dislocated by muscular contraction.

Animals↗
PubMed1975

Microautoradiographic study of cell proliferation in compensatory renal growth.

DNA synthesis in the renal parenchyma was studied by electron microscopic autoradiography 48 and 72 hours after unilateral nephrectomy in mice and weanling rats. The proportion of labelled nuclei belonging to the epithelium, endothelium, interstitial areas, or circulating cells was evaluated. Most of cells showing DNA synthesis were epithelial but many belonged to stroma. All the nephron segments were found to participate in compensatory hyperplasia, with a greater contribution, however, of the proximal convoluted tubules. DNA synthesis by the capillary endothelial cells occurred later than the peak epithelial mitotic activity. The site of DNA synthesis in nuclei was the euchromatin, the silver grains being uniformly distributed throughout the nuclear areas with condensed chromatin, and more seldom in the nuclear envelope areas or that of the perinucleolar satellites.

Animals↗
PubMed1975

Aminoacetonitrile (AAN)prevents connective proliferation in rat liver induced by tetrachlorcarbon. Continuous concomitant administration of AAN.

A total dose of 10 g/kg body weight of aminoacetonitrile distributed almost evenly over 35 days prevents formation of connective bands and damage of hepatocytes in the liver of rats submitted to CCl4 inhalations at a partial pressure of 1/6 atm, eight times within the same interaval. Control animals exhibited the usual pattern of CCl4 injury.

Acetonitriles↗
PubMedDate not supplied

The size distribution of thyroid follicles in single thyroid glands, a peculiar problem of particle size distribution in stereology.

Follicle sections vary in size according to their inclination mainly in hypertrophied thyroids. Sagittal sections elicit a shift to small classes, while transversal sections, to large classes. There is no mathematical transformation able to convert data obtained by sections into "true" sizes of follicles, as may be achieved by isolation. All papers emphasizing only section diameters and inferring about follicle size must be cautiously interpreted, and even discarded, if they tend to establish differences in follicle size solely on that basis. Follicle isolation is necessary if we need to establish follicle size and shape. Although proportions are almost stable for rats of the same age and weight, the proportions of follicle size may vary, as dependent on age and other internal and external conditions. The situation is most complicated by colloid accumulation; but despite these impedimenta, TSH secretion enlarges the follicles, a situation hitherto not well established. Cell enlargement is consequently followed by follicle enlargement, despite colloid resorption.

Animals↗