Mamoru Miyairi

Aggregation of platelets in the mesenteric microcirculation of the rat induced by α- toxin (phospholipase C) of Clostridium perfringens

Abstract We have investigated the effects of purified α-toxin (phospholipase C) of Clostridium perfringens ( Yamakawa and Ohsaka , 1977) on the behavior of cellular components in the microcirculation, using cinematography on a microscopic level and electron microscopy. We demonstrated that after topical application of α-toxin to the mesentery of the rat, rolling of leucocytes along the vessel wall and sticking of leucocytes to the vessel wall occurred in venules but not in arterioles. Some of the leucocytes remained attached to the vessel wall. Thrombi were formed frequently in venules and capillaries, and at a later stage, in arterioles. With time, thrombi increased in number and size, leading eventually to stasis of the blood stream. Thrombi were also observed frequently in the mesenteric microcirculation when toxin was injected into the jugular vein of the rat. The experiments with adenosine pretreatment followed by topical application of α-toxin to the mesentery suggested that the formation of thrombi induced by this toxin does not involve the mediation of ADP. Electron-microscopic examination confirmed the formation of thrombi consisting solely of platelets. It was concluded that thrombosis must be involved as an early step in the pathogenesis of necrosis caused by α-toxin. The death of the animals injected intravenously with α-toxin may be due, at least in part, to thrombosis. It is possible that thrombosis induced by α-toxin may be one of the factors involved in the causation of toxemia often manifested in the late stage of gas gangrene.

In vivo visualization of lymphatic microvessels and lymphocyte migration through rat Peyer's patches

BACKGROUND/AIMS In the small intestine, lymphocytes migrate through Peyers patches. The distribution of lymphatic microvessels in rat Peyers patches and lymphocyte traffic through them were studied. METHODS Vital dyes were injected via a micropipette into the Peyers patches tissue to fill lymphatic microvessels and to stain lymphocytes in lymphatic microvessels. RESULTS Direct microscopic observation revealed a dense plexus of lymphatic microvessels in the perifollicular and interfollicular areas. Injection of the dyes into the germinal center failed to delineate lymphatic microvessels. The lymphatic microvessels in the perifollicular area were filled with lymphocytes. Most lymphocytes in the perifollicular lymphatics stayed in the lymphatic microvessels. Some lymphocytes became detached and drained into lymphatic microvessels in the interfollicular areas. Lymphocytes then moved toward the submucosal lymphatics beneath the villi around the Peyers patches. The interfollicular lymphatics did not display contractile activity but had valves. Opening and closing of valves was synchronized with the respiration and the back and forth flow of lymphocytes. CONCLUSIONS There are numerous lymphocytes in a dense lymphatic network in the perifollicular and interfollicular areas of Peyers patches. This well-developed lymphatic network has the potential capacity for storage of lymphocytes and modulation of lymphocyte migration.

Budd-Chiari syndrome associated with protein-losing enteropathy.

Budd-Chiari syndrome associated with protein-losing enteropathy is reported. A 26-year-old male suffered from ascites, edema in the lower extremities, and engorgement of ascending veins on the abdominal wall. The diagnosis of Budd-Chiari syndrome was made by inferior vena cavography. The 131I-polyvinylpyrrolidone test showed the association of protein-losing enteropathy. The surgical operation was performed successfully, resulting in a marked improvement of signs and symptoms. To date, no similar case has yet been reported. There are, however, a number of reported cases of hypoproteinemia in Budd-Chiari syndrome, which might have been associated with a protein-losing enteropathy.

Effect of Colchicine on Intestinal Alkaline Phosphatase Activity during Linoleic Acid Absorption in Rats

The purpose of this study is to examine whether intestinal alkaline phosphatase (IAP) plays a role in transporting lipoproteins to lymphatics during fat absorption. In control rats, the increased activity of IAP in intestinal lymph was observed parallel with the amount of absorbed linoleic acid. In colchicine-treated rats, lymphatic absorption of intraduodenally administered linoleic acid was decreased and administered lipid was transported slowly to lymphatics, mostly in the form of free fatty acid. However, the equal or slightly larger amount of output of IAP to lymphatics was observed in spite of the decrease in lipid absorption in colchicine-treated rats. Histochemically, prolonged activity of IAP in stroma and submucosal lymphatics was found in colchicine-treated rats fed with fat. These results suggest that microtubules are not involved in IAP transport into lymphatics, and these data do not necessarily rule out that IAP plays a role in lipoprotein transport.

Role of plasma histamine in liver injury clinical and experimental investigations

SummaryPlasma histamine level (PHL) was evaluated by a modified fluorometric assay (Suzuki) in the patients with various forms of liver disease as well as rabbits with liver injury. And the data obtained were compared with liver function tests in assessing the stage and prognosis of hepatic dysfunction.In acute hepatitis, if its prognosis was “good”, as was also shown in the animal group with single dose administration of CC14, the level of plasma histamine attained a peak before that of serum transaminases, and returned to normal prior to that of the latter. In persistent and chronic hepatitis, although correlation betweenPHL and other liver function tests was poor and variable,PHL remained high. And the estimation ofPHL during the course of this state showed that it was elevated prior to that of serum transaminases, indicating high level of plasma histamine in this state, even in apparent “steady state”,’ worsening of the disease. In liver cirrhosisPHL correlated with the degree of serum transaminases as well as serum gammaglobulin. In “poor prognosis” group (patients with hepatic coma and rabbits treated with consecutive administration of CCI4)PHL increased extremely high, which was contrasted with the lowered levels of transaminases.These results strikingly suggest that histamine is involved in liver injury and estimation of PHL in the course of hepatic disorder is useful, for a prediction of prognosis.

Pathological and pathophysiological study on intestinal lymphatic system in fat absorption

SummaryPathological and pathophysiological study on the intestinal lymphatics was carried out clinically and experimentally. Jejunal biopsy study revealed marked dilatation of intestinal lymphatics in liver cirrhosis with ascites and BehÇet’s disease as well as protein-losing enteropathy. Lymphangiographic study showed also abnormal findings in above-mentioned diseases. In cases of McKee dogs in which mechanism of blockade of lymphatic flow was already clarified, McKee dogs showed marked malabsorption of fat. When lymphatic flow was blocked mechanically at the thoracic duct, fat accumulation was seen in the absorptive cells as well as in dilated intestinal lymphatics. In administration of colchicine to rats, fat accumulation was seen in the matrix of absorptive cells as well as in the endoplasmic reticulums and Golgi apparatus. However, amorphous substances instead of chylomicrons were seen in dilated intestinal lymphatics. These studies suggested that a tract of fat transportation from intestinal cells to the thoracic duct should be considered as a functional unit in fat absorption.