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ABSTRACT: We encountered the co-existence of an aberrant origin of the right subclavian artery and a myocardial bridge on the left anterior descending coronary artery in the cadaver of an 80-year-old Japanese woman during the course of educational dissection at Nagoya City University Medical School. We document the precise gross anatomical findings with some morphometric measurements. Neither an aberrant origin of the right subclavian artery nor the cardial myocardial bridge is a very rare anomaly, but a case of both anomalies being found in the same body is very rare. We believe this is the first report of the simultaneous occurrence of these two anomalies.
Folia morphologica 06/2005; 64(2):109-14. · 0.52 Impact Factor
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ABSTRACT: Many studies have described the ultrastructure of the dorsal root ganglia in various embryonic and adult animals, but in spite of the efforts of many investigators the functional role of the satellite cells in this tissue is not clearly understood. In this study, we discuss the function of this cell type based on the concept of cell-to-cell interaction through gap junctions. Five male 60 day-old Wistar strain rats were used. All animals were anesthetized with pentobarbital and perfused with glutaraldehyde fixative, then the dorsal root ganglia in levels L4, L5 and L6 were taken from each rat. After postosmication, the specimens were prepared for observation by transmission electron microscopy. All nerve cells were completely surrounded by satellite cell cytoplasmic expansions. The boundaries between adjacent nerve cells and satellite cells were complicated due to the presence of perikaryal projections of nerve cells. Gap junctions which showed the typical trilamellar structure of plasma membranes were found mainly between satellite cell processes belonging to the same nerve cell. On the other hand, some gap junctions were found between the satellite cell projections belonging to different nerve cells. The size of the gap junctions ranged from 300 to 400 nm. No gap junctions were associated with the plasma membrane of any nerve cell. In conclusion, only satellite cells can share free transcellular exchange of cytoplasmic molecules such as ions, amino acids, sugars and several second messengers including cAMP and inositol 1,4,5-triphosphate by way of gap junctions in dorsal root ganglia.
Anatomical Science International 07/2001; 76(3):297-302.
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ABSTRACT: We investigated the effects of hydrocortisone on the formation of gap junctions in and the growth of cilia on folliculo-stellate cells. The male rats of experimental groups were given daily intraperitoneal injections of 5 mg/kg of hydrocortisone from Day 20 to 60. Five rats were killed at ages 10, 20, 30 and 40 days after initiation of injections, and the pituitary gland was removed from each rat. Then, the specimens were prepared for observation by transmission electron microscopy. A delay in the formation of gap junctions between folliculo-stellate cells was observed in hydrocortisone treated rats compared with control rats on Day 30, 40 and 50. Another finding in the present study was the increase of ciliated follicles on Day 40 and 50 in the hydrocortisone treated groups, simultaneous with the delay in gap junction formation. The results suggest that hydrocortisone has a suppressive effect on the gap junction formation between folliculo-stellate cells, and loss of intercellular communication by way of gap junctions may lead to alteration of morphological development of the cell.
The Anatomical Record 03/2001; 262(2):169-75.
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ABSTRACT: The size of a substance is a major factor determining whether it can permeate the wall of synovial capillaries. The maximum diameter of particles that can move across the synovial capillary wall has generally been thought to be 50 nm. We studied the permeability of the synovial capillaries of the rat between day 20 and 30 after birth using a polystyrene particle whose diameter was 240 nm. In addition using lecithin-coated polystyrene particles, we studied the maturation of the barrier function supported by endothelial and peripheral cells against foreign bodies. Lecithin-coated particles were found within the fibroblast-like synovial cells near the capillary in the 20 day-old rats, while non-coated particles remained in the endothelial wall and in the peripheral cells of capillaries. In the 30 day-old rats, lecithin-coated particles were present in the peripheral cells and the neighboring synovial cells; however, the non-coated particles were never found in the synovial or perisynovial cells. The present study shows that the size of the transportable substance by transcytosis may be larger than previously thought. Furthermore, the synovial capillaries functionally changed between day 20 and 30 suggesting that active movement of the joint led to the functional maturation of the synovial capillaries.
Anatomical Science International 11/2000; 75(5):407-11.
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ABSTRACT: Since MacConaill first reported the existence of a thin additional layer of the articular cartilage and named it the lamina splendens, there have been various opinions as to the role of this layer in the lubrication of the articular surface. We studied the superficial portion of the articular cartilage in the 20 day-old and 30 day-old rats using light and transmission electron microscopy. Furthermore, we studied the articular cartilage of the rat whose "cover layer" had been removed mechanically. Also, intraarticular latex beads injection, intraarticular dye injection using lithium carmine and supravital staining experiments were performed. On day 20, dye injected intraarticularly was clearly observed by light microscopy in chondrocytes situated in the deeper layers. The dye injected in the 30 day-old rats, however, was not seen in the chondrocytes but was found only in the superficial layer. Dye was found in the chondrocytes when supravital staining was performed in the articular cartilage of 30 day-old rats after mechanical removal of the cover layer. By transmission electron microscopy, a superficial layer consisted of fine filamentous structures was observed on the articular surface of the 30 day-old rats. The cover layer was destroyed by intraarticular injected latex beads in 30 day-old rats. These findings strongly support the idea that the cover layer acts as a barrier against substances which invade from the surface of the articular cartilage. The development period of the cover layer coincides with the initiation of weight bearing, and joint cartilage debris and pressure changes might further promote maturation.
Anatomical Science International 01/2000; 74(6):631-7.
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ABSTRACT: To study phagocytosis in synovial cells at the synovium-cartilage junction, we used polystyrene latex spheres which induced no infiltration of inflammatory cells into the synovial tissues and observed them for a long term period. The latex bead suspension was injected into the knee joint cavities of 60 day-old male Wistar rats. The animals were then sacrificed at 1, 4, 7, 14, 28 and 56 days after the injections and their synovial tissues including the patellar cartilage were resected for subsequent examination with the transmission electron microscope. On day 1, particles were phagocytised intensively by both type A (macrophage-like) and type B (fibroblast-like) cells. Particles were more numerous in the cytoplasm of type A rather than type B cells. The number of synovial cells containing particles and the number of particles present in these cells decreased remarkably on day 4. By day 7, particles were also observed in the tendon. On day 14, particles were observed in the cytoplasm of chondrocyte. It was noted that particle density within cells began to increase again after day 28. On day 56, numerous particles were observed in type A and type B cells and moreover within the intercellular matrix. Even tendon cells actively engulfed the particles. The results of the present study suggest that both type A and B synovial cells, chondrocytes and tendon cells possess the ability to phagocytise foreign materials. Moreover, the possibility is proposed that the synovium-cartilage junction is the point where the synovial fluid exits and particles drain via the blood circulation.
Anatomical Science International 11/1999; 74(5):525-35.
