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Biomedical subjects

N Aoki

Publications and source records attributed to N Aoki.

At least 667 records · Page 37Linked to original sources

Cross-linking of alpha 2-plasmin inhibitor and fibronectin to fibrin by fibrin-stabilizing factor.

Two plasma proteins, alpha 2-plasmin inhibitor and plasma fibronectin, are cross-linked to fibrin by plasma transglutaminase (R-glutaminyl-peptide : amine gamma-glutamyl-yltransferase, EC 2.3.2.13, fibrin stabilizing factor) when blood coagulation takes place. The cross-linking reactions of these proteins were analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate (SDS) using these radioactively labeled proteins. Both proteins were cross-linked exclusively to the alpha-chain of fibrin, and each of these cross-linking reactions proceeded independently without being influenced by the other cross-linking reaction. The cross-linking of fibronectin to the alpha-chain proceeded steadily at a rate similar to that of the cross-linked polymerization of the alpha-chain. In contrast, the cross-linking reaction of alpha2-plasmin inhibitor to fibrin proceeded markedly faster than that of fibrin polymerization but did not proceed further after reaching a certain relatively low level of cross-linking. Most of the cross-linked alpha 2-plasmin inhibitor molecules at this stage of the fibrin cross-linking were in the form of complex with the alpha-chain monomer. The complex with the alpha-chain monomer was gradually transformed to a complex with the alpha-chain polymer as the cross-linking polymerization of the alpha chain proceeded. The rate of the transformation was the same as that for the disappearance of the alpha-chain monomer, indicating that whether the alpha-chain was cross-linked to alpha 2-plasmin inhibitor or not, the alpha-chain underwent cross-linking polymerization at the same rate.

Blood Coagulation↗

Suppression of PHA-induced lymphocyte blastogenesis by concomitant presence of PPD in the culture.

PHA-induced lymphocyte blastogenic response was remarkably suppressed by the simultaneous presence of PPD in cultures of lymphocytes derived from individuals sensitized to PPD, but not affected by the presence of PPD when the cultures contained lymphocytes from an individual not sensitized to the protein. This double stimulation blastogenesis study with PHA and a specific antigen is feasible as a simple and rapid test to measure cell-mediated immunity to the antigen.

Antigens, Bacterial↗

A case report of myasthenia gravis associated with Hashimoto's thyroiditis.

An unusual case of myasthenia gravis is presented. The disease was clinically established in a 71-year-old Japanese woman by an electromyographic, pharmacologic test and anti-acetylcholine receptor (anti-AChR) antibodies demonstrated in the circulating blood. The coexistence of Hashimoto's thyroiditis was diagnosed by the presence of a diffuse thyroid enlargement, anti-thyroglobulin and anti-microsomal antibodies and a lowered thyroidal 131I uptake. A delusion of persecution developed during the treatment with pyridostigmine and ephedrine chloride, but the symptom disappeared after discontinuing the use of ephedrine chloride.

Aged↗

Acute hepatic cell necrosis experimentally produced by viral agents in rabbits.

Acute and extensive hepatic cell necrosis was produced experimentally in rabbits by means of the Shwartzman mechanism using adeno- and hepatitis B viruses. The change that occurred in the liver was quite severe, namely, areas of hemorrhagic necrosis of various sizes in gross appearance and lytic-coagulative necrosis with hemorrhage and leukocyte-mononuclear cell infiltration histologically. Thrombi formation was noted in and around the necrotic areas, and it was not unusual to see necrosis of an entire lobe. This seems to be a model, to some extent, for human fulminant hepatitis caused by hepatitis virus infection, and suggested that some nonspecific reaction such as intravascular clotting may also play an important role in causing or complicating acute, severe, and extensive necrosis of the liver in human cases. Heparin administration very effectively prevented such hepatic necrosis, which supports the view that the change we observed in the liver was really the Schwartzman reaction; further, it is reminiscent of the fact that heparin administration is sometimes effective in fulminant hepatitis treatment if given at te appropriate stage of the disease.

Acute Disease↗

Multiple aneurysms of the visceral arteries with migrating vascular bruit on postural change: a case report.

Multiple aneurysms of the gastroepiploic artery and the ileocecal branch of the superior mesenteric artery were found in a 68-year-old male patient by angiography. The patient presented with one-hour postprandial epigastric pain of 10 years duration. Abdominal bruit was auscultated at the two different sites, one of which shifted downwards upon upright position. From the freely movable nature of the great omentum, this bruit, migrating upon postural change, was most likely from the gastroepiploic artery aneurysms. The aneurysms were excised and the abdominal bruit disappeared. The etiology of the aneurysms was suggested to be arterial fibrodysplasia histologically. From this experience, it was stressed that postural change should be added to a routine physical examination to rule out an aneurysm from the freely movable great omentum.

Aged↗

Pancreatic cancer with metastasis to the larynx.

A laryngeal metastasis from pleomorphic carcinoma of the pancreas is described. The patient was a 70-year-old male. The tumour was located on the right margin of the epiglottis. Bilateral neck lymph node metastases were also found. The patient underwent supraglottic laryngectomy, right radical neck dissection and left suprahyoid neck dissection. Following surgery, the patient's general condition deteriorated day by day, and one month after the surgery he died. The autopsy findings demonstrated a big mass of cancer in the pancreatic tail, multiple lymphatic metastases, carcinomatous peritonitis, and possibly a lymphatic spread of the pancreatic cancer to the larynx.

Aged↗

Cross-linking of alpha 2-plasmin inhibitor to fibrin by fibrin-stabilizing factor.

The concentration of alpha 2-plasmin inhibitor in blood plasma is higher than that in serum obtained from the blood clotted in the presence of calcium ions, but is the same as that in serum obtained in the absence of calcium ions. Radiolabeled alpha2-plasmin inhibitor was covalently bound to fibrin only when calcium ions were present at the time of clotting of plasma or fibrinogen. Whereas, when batroxobin, a snake venom enzyme that lacks the ability to activate fibrin-stabilizing factor, was used for clotting fibrinogen, the binding was not observed. When fibrin-stablizing, factor-deficient plasma was clotted, the specific binding of alpha 2-plasmin inhibitor to fibrin did not occur even in the presence of calcium ions and the concentration of alpha 2-plasmin inhibitor in serum was the same as that in plasma. Monodansyl cadaverine, a fluorescent substrate of the fibrin-stablizing factor, was incorporated into alpha 2-plasmin inhibitor by activated fibrin-stablizing factor. All these findings indicate that alpha 2-plasmin inhibitor is cross-linked to fibrin by activated fibrin-stabilizing factor when blood is clotted. Analysis of alpha 2-plasmin inhibitor-incorporated fibrin by sodium dodecyl sulfate gel electrophoresis showed that the inhibitor was mainly cross-linked to polymerized alpha-chains of cross-linked fibrin. Cross-linking of alpha 2-plasmin inhibitor to fibrin renders fibrin clot less susceptible to fibrinolysis by plasmin.

Calcium↗