Kubo. Vascular endothelial growth factor in patients with high-altitude pulmonary edema.

The glomerular basement membrane of rat kidneys were three-dimensionally observed by quick-freeze and deep-etch replica methods at high resolution. The middle layer (lamina densa) was composed of 6 to 10 nm fibrils which formed a meshwork structure. The space between the fibrils had polygonal shape. The average long dimension of the space between fibrils was 17 nm and the short one was 13 nm. At the outer layer (lamina rara externa), fibrils connected podocytes perpendicularly with the meshwork of the middle layer. At the inner layer (lamina rara interna), similar perpendicular fibrils also connected endothelial cells with the meshwork of the middle layer. This is the first report to visualize the three-dimensional meshwork structure of the middle layer (the lamina densa) in situ. The function of anchoring podocytes to the lamina densa was suggested in the perpendicularly arranged fibrils of the outer layer. The quick-freeze and deep-etch method is useful in analyzing filamentous ultrastructure in glomeruli, and will be applied to clarifying pathological ultrastructure in kidney diseases.

We observed hepatocyte cytoskeletons in phalloidin-treated rats by the quick-freezing and deep-etching method in three dimensions and compared them with the ultrastructural findings on conventional ultrathin sections. The numbers of microvilli in dilated bile canaliculi were decreased in the rats treated with phalloidin for 1 wk. In hepatocytes the cytoplasm around bile canaliculi could be divided into three layers, increased microfilament layer, cell organelle layer of secretory system and increased smooth surface endoplasmic reticulum layer. In the rats treated with phalloidin for 4 wk, microfilaments were extended into the cytoplasm near the nucleus in addition to the increased number of large lysosomes and microtubules. In both groups, three-dimensional structures of microfilaments could be visualized around bile canaliculi and along cell borders by the quick-freezing and deep-etching method. The branching microfilaments with the diameters of 7 to 10 nm were directly attached to other filaments, cell organelles or cytoplasmic sides of cell membranes. Moreover, bundled intermediate filaments were increased around peribiliary microfilaments associated with long-term cholestasis. It is suggested that excessive accumulation of peribiliary microfilaments disturb the secretion of bile components into bile canaliculi. The cytoskeletal reorganizations of intermediate filaments seem to alter the arrangements of various cell organelles.

The three-dimensional ultrastructure of the glomerulus in serum sickness nephritis has been investigated by the quick-freezing and deep-etching method. Compact granular immune deposits were localized in filamentous networks in the lamina densa and mesangial matrices. These constitutional fibrils with diameters of 8-15 nm, were directly attached to the immune deposits. The filamentous networks became markedly loosened around the deposits. In podocytes, reticular microfilaments with positive decoration by myosin subfragment 1 (S1) were increased in flattened foot processes and directly attached to the cell membranes. Fine filaments with diameters of 4-7 nm were undecorated by S1 and connected with actin filaments as cross-bridges. Intermediate filaments were also increased in the cell bodies and primary processes of podocytes. Connecting fibrils in lamina rara externa were partially disrupted. The immune deposits were primarily detected in the networks of lamina densa and actually destroyed the size barrier composed of filamentous networks. Moreover, the mesangial deposits also disorganized mesangial networks to probably alter mesangial flow through the matrices. Increased actin filaments in foot processes seemingly reinforced the cell membranes and the connecting fibrils in lamina rara externa, which prevented the initial detachment of podocytes from the basement membrane.

No abstract

The three-dimensional ultrastructure of glomerular sclerosis in the chronic phase of Masugi nephritis was investigated using a quick-freezing and deep-etching method. Newly formed mesangial matrix, which was increased in the axial portions, was composed of fine fibrillar networks similar to those in the lamina densa of the basement membrane. These fibrils were 10-20 nm in diameter and directly attached to the cell membranes of mesangial cells, endothelial cells and podocytes by connecting fibrils. Moreover, thicker fibrils with diameters of 20-30 nm were present in the networks and were connected with cross-bridges. A newly formed matrix of fine fibrillar networks was also seen in the areas of mesangial interposition in the glomerular capillary wall. The border between the matrix and lamina densa was unclear. The fibrils organizing the networks of lamina densa of the glomerular loop were thickened, with some decoration. Connecting fibrils were disrupted in the areas of endothelial detachment. It is suggested that prolonged tissue injury with endothelial detachment might induce mesangial sclerosis composed of fine fibrillar networks. The increase in density of the networks seemingly interfere with the contractile function of mesangial cells, which is followed by alteration of mesangial flow.

In order to characterize the pathological features of high altitude pulmonary edema (HAPE) occurring at moderate altitude in Japan, we performed routine hematoxylin and eosin (HE) staining in lung materials from HAPE autopsied cases. We also undertook advanced immunohistochemical staining for observation of type II pneumocytes, pulmonary surfactant (PS), and mast cells in the lung of HAPE cases to examine the biological changes within the lung parenchyma. The pathological findings of HAPE were characterized by alveolar edema, congestion of pulmonary vessels, alveolar hyaline membranes, alveolar hemorrhage, and multithrombi and fibrin clots, but maintained alveolar structure. The immunostaining results showed that the type II pneumocytes were cellular fusion, deformity, and exfoliation from the walls of alveoli; the PS not only lined the alveolar surface, but was also patchily distributed within alveoli; and the number of mast cells were increased (9.0 +/- 0.9 cells/mm(2)) compared to that in controls (1.1 +/- 0.4 cells/mm(2)) (p < 0.01). We conclude that the pathological features of HAPE at moderate altitude in Japan are similar to others reported worldwide, and that the type II pneumocytes, PS, and mast cells may contribute to some extent to pathophysiological parts in the development and progression of HAPE.

We report a rare case of cerebellar degeneration that was diagnosed at autopsy in a patient who developed lithium intoxication accompanied by neuroleptic malignant syndrome. This 63 year old female, who suffered from manic depressive psychosis, had received lithium bicarbonate at a daily dose of about 1OOOmg for 4 years. She developed a high fever and extrapyramidal symptoms resembling a neuroleptic type of malignant syndrome and died 1 month later. Autopsy revealed an almost complete loss of Purkinje cells with a mild reduction of granule cells in most areas of the cerebellar hemisphere and vermis, except for the tonsil and flocculus, and mild gliosis in the dentate nucleus. In cases of suspected lithium intoxication, one must be alert to the possibility of neuroleptic malignant syndrome and to prevent cerebellar degeneration.