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Biomedical subjects

M Mito

Publications and source records attributed to M Mito.

At least 91 records · Page 5Linked to original sources
PubMed1987

Cells of origin innervating the liver and their axonal projections with synaptic terminals into the liver parenchyma in rats.

By utilizing a horseradish peroxidase (HRP) axonal flow technique for retrograde tracing, and electron microscopic techniques, attempts were made in adult Wistar rats to elucidate the central organization of the parasympathetic hepatic innervation. The results were as follows: 1) cells of origin directly innervating the liver were located mainly in the left dorsal motor nucleus of the vagus (DMV). Their mean number was 175 with a standard deviation of 14 (n = 14). 2) the hepatic branch of the vagus consisted mostly of unmyelinated nerve fibers. The mean number of unmyelinated fibers was 2072 with a standard of 137, while that of myelinated fibers was only 13 with a standard deviation of 4 (n = 10). 3) nerve terminals were found in two different regions; one adjacent to the vasculature in the portal area, and the other in the space of Disse among hepatic parenchymal cells. These nerve terminals contained several synaptic vesicles different both in their form and size.

Animals↗
PubMed1986

DDAVP in acquired von Willebrand syndrome associated with multiple myeloma.

The response to a single intravenous infusion of 1-deamino-8-D-arginine vasopressin (DDAVP, desmopressin) was studied in two patients with acquired von Willebrand syndrome associated with IgG-kappa myeloma. Following infusion of DDAVP (0.3-0.4 micrograms/kg), prolonged bleeding time was normalized; plasma ristocetin cofactor activity, von Willebrand factor antigen, and factor VIII activity were remarkably increased; and high-molecular-weight forms of von Willebrand factor were demonstrated by crossed immunoelectrophoresis in both patients. Excellent hemostasis was achieved following administration of DDAVP in one patient when it was used for the treatment of gum bleeding and for the prophylaxis of bleeding during and after dental extractions. These observations suggest that DDAVP is an effective alternative to blood products for at least some patients with acquired von Willebrand syndrome in addition to patients with inherited von Willebrand disease, hemophilia A, and uremia.

Blood Coagulation Tests↗
PubMed1986

Cryopreservation of fetal rat liver tissue--a morphological investigation.

The present study was undertaken to define optimal conditions for cryopreservation of fetal rat liver tissue fragments. First, various cooling rates (1, 4, 10, 20 and 30 degrees C/min) and preserving temperatures (-20, -80 and -196 degrees C) were examined. Next, various concentrations of Me2SO (5, 10, 20 and 30 per cent vol/vol) were examined by freezing at a rate of 4 degrees C/min to -80 degrees C before transfer to -196 degrees C. All samples were preserved for at least one week. After recovery from cryopreservation, the fragments were transplanted into the spleens of syngeneic rats. Histological assessment of the grafts was made one month after transplantation. Consequently, the optimal cryopreserving conditions for fetal rat liver fragments were defined as follows: cooling rate was 1 to 10 degrees C/min, preserving temperature was at -196 degrees C, concentration of Me2SO was 20 per cent (final concentration: 10 per cent). In the long term observation, the stored liver fragments could be differentiated into adult hepatocytes and the surviving hepatocytes showed little difference from the nonfrozen controls, either histochemically or ultrastructurally. The surviving hepatocytes in the stored transplants were less numerous than in the nonfrozen ones and hepatic cell plates and sinusoids were nil.

Animals↗
PubMed1986

Hepatic assist: present and future.

Fulminant hepatic failure due to acute massive liver cell necrosis is a complex pathophysiological entity, and treatment is still unsatisfactory. Artificial liver supports such as hemodialysis, hemoperfusion, and plasmapheresis have recently been used clinically to treat fulminant hepatic failure. However, survival rate has not improved as expected, although the consciousness of the patient has improved frequently. In this article the present status of clinical artificial liver support and basic research of hybrid artificial liver will be discussed. Moreover, the future aspects of total artificial liver support and hepatocyte transplantation for chronic liver failure will be introduced.

Adsorption↗
PubMed1985

Flow- and pressure-adapted portal arterialization in dogs.

The effects of portal arterialization after portacaval shunt were studied in dogs. Flow- and pressure-adapted portal arterialization was performed by mounting a Teflon cuff on an autogenous vein bypass graft between the hepatic stump of the portal vein and the right renal artery. Immediately following operation, the total hepatic blood flow and intrahepatic portal venous pressure were within normal range. Eight weeks after operation, the intrahepatic portal venous pressure remained within the preoperative range, while total hepatic blood flow had increased double or triple. However, structural change due to increased flow was absent in the liver, even sixteen months after operation. Body weight, liver enzyme chemistry, ICG clearance rate, and amino acid metabolism were well maintained for the entire period of investigation. These findings suggest that sequelae such as hepatic encephalopathy and impaired hepatic metabolism after portacaval shunt can be avoided by portal arterialization, in the presence of an appropriate flow and pressure.

Alanine Transaminase↗
PubMed1985

[The current and future aspects of liver cell transplantation].

Our previous experiment presented that isolated adult rat hepatocytes survived and proliferated markedly and they reconfigured macroscopic hepatic tissue occupying more than 50% of the spleen 27 months after transplantation. On the basis of the results, we have emphasized that the hepatized spleen provides many fundamental and clinical interests on hepatology. The morphlogical studies of the recomposed hepatic tissue revealed almost normal architecture of the liver except the lack of bile duct system. Prolongation of the survival time was obtained in rats with hepatized spleen which underwent a portacaval shunt several months earlier compared with animals without hepatized spleen, when the rats were completely devascularized. That means that the hepatized spleen can act as an auxillary liver. For the purpose of applying this experimental model clinically, liver cell autotransplantation was performed using dog and monkey. These resulted in recomposed hepatic tissue in the monkey's spleen 15 months after transplantation, but no survival of the transplanted hepatocytes in dogs. In human, we have been developed a new hepatocyte isolation technique and we can obtain approximately 10(6) isolated human hepatocytes (viability 55-86%) from the partially resected liver with the hand-made multiperfusion system. Finally, future problems of clinical application of the intrasplenic hepatocyte transplant were mentioned especially about the idea of the liver cell bank.

Animals↗
PubMed1982

Observations on the fine structure of long-survived isolated hepatocytes inoculated into rat spleen.

Hepatic parenchymal cells which were isolated from rats and transplanted into the spleens of syngeneic rats were evaluated by electron microscopy. Fine structure of the isolated hepatocytes demonstrated that, except for a decrease in glycogen particles and focal proliferation of smooth endoplasmic reticulum, the organelles were morphologically indistinguishable from normal cells. The most striking finding was that the cytoplasmic membranes of the inoculated hepatocytes morphologically and functionally differentiated during proliferation exhibiting biliary surfaces, perisinusoidal surfaces, and other surfaces. These proliferated hepatocytes reconfigured the space of Disse and the sinusoidal structure within the splenic parenchyma. Endothelial cells with several fenestrations and fat-storing cells containing lipid droplets were also found but Kupffer cells were not detected. Electron microscopy demonstrated that adult isolated hepatocytes survived and proliferated in the rat spleen for more than 16 mo, retaining the structural elements of hepatic cytoplasm while reconfiguring a hepatic sinusoidal architecture.

Animals↗