scholarly journals THE MORPHOGENESIS OF NONPARASITIC LIVER CYSTS

2020 ◽  
Vol 28 (3) ◽  
pp. 51-57
Author(s):  
Genrietta G. Freynd ◽  
Elena V Zhivaeva

As a result of the introduction of imaging research methods into clinical practice, the frequency of detection of cavities in the liver has significantly increased, among which nonparasitic cysts have not been sufficiently studied. The paper provides an overview of the most commonly used classifications of this pathology. Clinical and radiological manifestations of cysts were investigated based on the analysis of the results of computed tomography, magnetic resonance imaging and ultrasound sonography of 175 patients (109 with solitary cysts and 66 with polycystic liver). The tissues of the resected areas of 81 cysts and adjacent liver tissue were studied by histological and immune-histochemical methods. Various variants of liver cysts were identified: polycystic cysts, solitary cysts and the rarest variant - ciliated anterior-intestinal hepatic cysts. The morphological and histogenetic features of solitary and ciliated anterior-intestinal hepatic cysts, as well as changes in the liver tissue adjacent to the cavities, are described. Polycystic is characterized by the presence of cavities of various sizes, with thin connective tissue partitions and a lining of cubic or flattened epithelium. The lining of solitary cysts is represented by cubic, cylindrical, sometimes multi-row epithelium. Immature biliary structures in the form of von Meijenburg complexes, islets of hepatocytes, conglomerates of dysplastic vessels are revealed in their wall among the cells of connective tissue. Ciliated anterior-intestinal hepatic cysts contain components of the primary intestine wall - a lining of a cylindrical ciliated epithelium, a layer of loose connective tissue, a muscle layer, a connective tissue capsule. Morphological studies made it possible to establish violations of embryogenesis in various types of cysts. Ciliated anterior intestinal hepatic cysts develop from the anterior section of the primary intestine, while solitary cysts are derived from its middle section. Migration of the developing buds of bronchioles from the cranial part of the primary midgut into the hepatic diverticulum determines the presence of all components of the wall of the hollow organ - cylindrical ciliated epithelium, loose connective tissue, bundles of smooth muscle fibers. Simple solitary cysts are the result of abnormal remodeling of the embryonic ductal lamina, thus being a developmental abnormality of the middle section of the primary midgut. Morphological examination of the liver tissue adjacent to the walls of the cysts reveals hypoplasia of lobules, persistence of elements of the embryonic ductal plate in the form of cords and complexes of the biliary epithelium, foci of ductopenia, von Meijenburg complexes, and various variants of vascular dysplasia.

1985 ◽  
Vol 55 ◽  
Author(s):  
L.-H. Yahia ◽  
G. Drouin ◽  
C.-H. Rivard

ABSTRACTSpinal ligaments were obtained from normal and scoliotic individuals. Detailed morphological studies were carried out on the yellow, interspinous and supraspinous ligaments by light and scanning electron microscopy. Normal yellow ligaments are mostly constituted of dense elastin fibers with only a few collagen fibers and sparse blood vessels, while in normal interspinous and supraspinous ligaments, the presence of collagen is highly dominant. In the latter structures, the collagen fascicles are characterized by a regular waviness morphology. The fibrils constituting the fascicles appear either parallel or helical with respect to the fascicle axis. Structural changes are observed in the spinal ligaments of patients with congenital as well as idiopathic scoliosis. For yellow ligaments, only slight differences are found between normal and scoliotic specimens. However, alterations in collagen waviness and architecture are observed mainly in the supraspinous ligaments and to a lesser extent in the interspinous ligaments. In addition, increases in the cellularity, loose connective tissue and vessels are found in both forgoing ligaments. These results indicate that the more pronounced scoliosis-related changes occur in ligaments having the farthest distance from the axis of flexion-rotation.


The Angler ( Lophius piscatorius ) is a fish much modified for a bottom habit, and apart from many peculiarities of form and structure associated with this particular mode of life, is remarkable for the looseness of its skin and the abundance of soft connective tissue that separates it from the underlying fascia and muscles. Within this layer of loose connective tissue lie many of the larger trunks of the lymphatic system, mostly of very considerable size and easy to inject. The fish thus furnishes material better than most for the study of this system.


2007 ◽  
Vol 32 (5) ◽  
pp. 556-559 ◽  
Author(s):  
M. C. SBERNARDORI ◽  
P. BANDIERA

The histopathology of the central parts of 40 A1 pulleys from adult patients with primary trigger fingers was studied using light and transmission electron microscopes and the findings were compared with those in a control series of 10 normal A1 pulleys. The evaluation of the normal A1 pulley revealed a bi-laminar structure. The deepest layer was composed of dense normal connective tissue. The outermost layer was formed by loose connective tissue. In trigger digits, it was possible to identify a tri-laminar structure. The deepest layer was composed of irregular connective tissue, formed by small collagen fibres and abundant extracellular matrix. A considerable amount of chondroid-metaplasia was present in this layer. The middle layer contained dense, normal connective tissue with some fibrocytes. The outermost layer was formed of loose connective tissue. In conclusion, there was an additional layer in the A1 pulley in pathological cases which was not present in normal pulleys.


2012 ◽  
Vol 44 (1) ◽  
pp. 5 ◽  
Author(s):  
Ramzi Mansour ◽  
Vincenzo Cavalieri ◽  
Gaetana Mazzeo ◽  
Kaouthar Grissa Lebdi ◽  
Agatino Russo

Some vine mealybug, <em>Planococcus ficus </em>(Signoret) populations in Tunisian vineyards have been morphologically and genetically characterized. The morphological examination was based on the main distinctive characteristics of species of <em>Planococcus</em>, namely the number and distribution of the multilocular disc pores and tubular ducts on the adult female. This showed the existence of two different vine mealybug populations in Tunisia. Likewise, in the molecular analyses, two separate clades were revealed in the neighbour-joining phylogenetic tree, supporting the morphological studies and suggesting that there are two distinct populations of <em>P. ficus</em> on grapevine in Tunisia.


1975 ◽  
Vol 142 (1) ◽  
pp. 41-49 ◽  
Author(s):  
E Linder ◽  
A Vaheri ◽  
E Ruoslahti ◽  
J Wartiovaara

Fibroblast surface (SE) antigen is present in fibrillar surface structures of cultured normal fibroblasts, shed to the extracellular medium, and is also found in circulation (serum and plasma). Malignant fibroblasts (transformed by viruses) do not express SF antigen on the cell surface. In this study the in vivo differentiation and distribution of SF antigen has been investigated in the developing chick embryo using cryostat sections and immunofluorescence. The major findings were: (a) SF antigen was detectable in the loose connective tissue of very early (2-to 3-day old) embryos. (b) Condensation of SF antigen was seen in various boundary membranes such as the glomerular and tubular basement membranes of the kidney, the boundary membranes of the notochord, yolk sac, and vitelline membranes and liver sinusoids. (c) SF antigen was found to be cell-type specific. It was seen as a fibrillar network in the loose connective tissue of different organs but not in the parenchymal cells. It was not found in muscle cells at any stage of development. (d) The antigen was present in the undifferentiated mesenchymal cells of the kidney; but not found after their development into epithelial cells of the secretory tubules. (e) Both in vivo and in fibroblast cultures SF antigen was distributed as a fibrillar network. These data indicate that SF antigen is a "differentiation antigen" restricted to certain cells of mesenchymal origin and character, and that is accumulates in the connective tissue during embryogenesis.


1991 ◽  
Vol 260 (3) ◽  
pp. G390-G398 ◽  
Author(s):  
F. Vogalis ◽  
S. M. Ward ◽  
K. M. Sanders

Electrical slow waves decay in amplitude as they conduct from the myenteric to the submucosal regions of the circular muscle layer in the canine pyloric sphincter. We used the partitioned chamber method to study the passive and active properties of pyloric muscles, and we found that length constants of circular muscles of myenteric region were significantly longer than muscles near the submucosal surface. These data suggested differences in either membrane resistance, junctional resistance, or cytoplasmic resistance. The first parameter was evaluated by measuring time constants in intact tissues and single cells isolated from the submucosal and myenteric regions. Membrane time constants were not different in the two regions, nor were differences found in the input resistances of isolated cells. Morphological studies failed to demonstrate differences in cell diameters in the two regions suggesting that cytoplasmic resistances are similar. These findings suggest that the different cable properties in the two regions may be due to differences in electrical coupling. Morphological examination revealed similar numbers of gap junctions between cells in the two regions, but large differences were noted in the size of muscular bundles. Muscles of the myenteric region were arranged into large, tightly packed bundles, whereas muscles of the submucosal region consisted of small bundles with an extensive extracellular space filled with connective tissue. We suggest that the difference in cable properties may be due to differences in electrical coupling between bundles. These data suggest that submucosal muscles function more like a multiunit smooth muscle, whereas myenteric muscles behave as a single unit.


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