Biomedical subjects
Publications and source records attributed to L Surchev.
The cardiovascular system of the dicephalus (2 spines, one pelvis) conjoined twins is being described. The heart consists of 2 atria and 3 ventricles. Various malformations are evident in the layout systematic and pulmonary circulation. The vascular system can be divided into 3 zones: an upper one--with an almost symmetrical duplication, a middle one--with an atypical pattern, and a lower one--with a normal pattern.
Described are the alimentary system, the respiratory system, the urogenital system and the endocrine glands of conjoined female twins. There were found to be present 2 esophagi, 2 stomachs, 2 duodeni, 2 pancreas and one large liver. The intestine is unique from the region of the jejunum to it's end. There were found to be present 2 tracheae and 4 lungs. The urogenital system appeared to be normal. A single deviation was noted with respect to the endocrine glands, in particular, the right adrenal gland had an additional part which entered the thorax through a cleft in the diaphragm.
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The peculiarities of the skeletal, muscular, and nervous systems of conjoined female twins (2 spines, one pelvis) is described judging from the examination of the 2 skulls, 2 vertebral columns, shoulder girdle of the intermediate connection between the trunks, deep muscles of the back, 2 separate central nervous systems, lack of changes in the muscles, of the anterior aspect of the thorax and anterolateral muscles of the abdomen; from what we have observed it is suggested that this is a case of uniovary twins whose separation began in the superior dorsal side but was incomplete in the ventral inferior parts. It is possible that this arose from accidents of fusion or fission of embryos.
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 nature of the IMPs and the functional significance of their mode of distribution were discussed.
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. The nature of the IMPs and the functional significance of their mode of distribution are discussed.
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. Its presence in the Schwann cell plasma membrane is only admittable. The ATPase activity of the compact myelin and axolemma was exclusively of alpha + type of Na+, K+-ATPase.