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Biomedical subjects

S Murashima

Publications and source records attributed to S Murashima.

At least 73 records · Page 4Linked to original sources

[Studies on C1 inactivator resistant fibrinolytic activity].

The fibrin lysis activity in the presence of enough quantity of C1 inactivator (C1.INA) is called C1.INA resistant fibrinolytic activity (C1.IRFA). C1.INA inhibits the activation of intrinsic fibrinolysis, therefore C1.IRFA is considered to reflect the extrinsic fibrinolytic activity mainly. We studied the effect of C1.INA using fibrin plate assay on fibrin lysis activity (FLA) and C1.IRFA in normal individuals and pregnant women, and studied the fluctuation of FLA and C1.IRFA during venous occlusion test (VO) or 1-deamino-8-D-arginine vasopressin (DDAVP) administration. After VO or DDAVP administration, the euglobulin lysis time (ELT) was reduced, FLA increased and C1.IRFA also increased. The increase in C1.IRFA accounted for most of the increase in FLA. Therefore, the increased fibrinolytic activity during VO or DDAVP administration is due to extrinsic fibrinolytic activity. In the pregnant women, the fibrinolytic activity was decreased during pregnancy and the low fibrinolytic activity is suggested to be involved in the low extrinsic fibrinolytic activity. The measurement of C1.IRFA is considered to be useful.

Complement C1 Inactivator Proteins↗

Characterization of particulate cyclic nucleotide phosphodiesterases from bovine brain: purification of a distinct cGMP-stimulated isoenzyme.

In the absence of detergent, approximately 80-85% of the total cGMP-stimulated phosphodiesterase (PDE) activity in bovine brain was associated with washed particulate fractions; approximately 85-90% of the calmodulin-sensitive PDE was soluble. Particulate cGMP-stimulated PDE was higher in cerebral cortical gray matter than in other regions. Homogenization of the brain particulate fraction in 1% Lubrol increased cGMP-stimulated activity approximately 100% and calmodulin-stimulated approximately 400-500%. Although 1% Lubrol readily solubilized these PDE activities, approximately 75% of the cAMP PDE activity (0.5 microM [3H]cAMP) that was not affected by cGMP was not solubilized. This cAMP PDE activity was very sensitive to inhibition by Rolipram but not cilostamide. Thus, three different PDE types, i.e., cGMP stimulated, calmodulin sensitive, and Rolipram inhibited, are associated in different ways with crude bovine brain particulate fractions. After solubilization and purification by chromatography on cGMP-agarose, heparin-agarose, and Superose 6, the brain particulate cGMP-stimulated PDE cross-reacted with antibody raised against a cGMP-stimulated PDE purified from calf liver supernatant. The brain enzyme exhibited a slightly greater subunit Mr than did soluble forms from calf liver or bovine brain, as evidenced by protein staining or immunoblotting after polyacrylamide gel electrophoresis under denaturing conditions. Incubation of brain particulate and liver soluble cGMP-stimulated PDEs with V8 protease produced several peptides of similar size, as well as at least two distinct fragments of approximately 27 kDa from the brain and approximately 23 kDa from the liver enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)

3',5'-Cyclic-GMP Phosphodiesterases↗

[Assessment of the biological activity of residual or recurrent neuroblastoma tumors with 131I-metaiodobenzylguanidine (MIBG) scintigraphy].

131I-Metaiodobenzylguanidine (MIBG) is now accepted as a useful agent for the diagnosis of adrenal medullary tumor. The aim of this paper is to evaluate 131I-MIBG for the assessment of the biological activity of residual or recurrent tumor after initial treatment in patients with neuroblastoma. Nineteen scans were performed for 9 patients, mean age 3.5 years-old. Computed tomography demonstrated paravertebral mass in six and metastatic liver tumor in four cases. Anterior and posterior images of the thorax and abdomen were taken 48-72 hours after injection of 7.4-18.5 MBq (0.2-0.5 mCi) 131I-MIBG. Positive images were obtained in 8 scans for four patients and followed by rapid growth of tumor and increased urinary dopamine. The biological activity of residual or recurrent tumor was thought to be high in these patients. Eleven scans for 5 patients revealed negative. In four of them, the tumor size reduced and urinary dopamine value remained within normal limits on the follow-up study. The tumor was assumed to have low biological activity in these patients. One case in which initial scan was negative became positive on the follow-up study. 131I-MIBG activity did not well correlate with urinary vanillylmandelic acid as compared with urinary dopamine. In conclusion, 131I-MIBG proved to be useful for assessing biological activity of residual or recurrent tumor of neuroblastoma and estimating the prognosis of the patient.

3-Iodobenzylguanidine↗

[Availability of DDAVP in hemostasis control for the breast tumor resection in a patient with thrombasthenia (type II)].

We reported a 33-year-old woman with thrombasthenia (type II) in whom 1-deamino-8-D-arginine vasopressin (DDAVP) was available for the hemostasis control during breast tumor resection. She has had recurrent nasal bleeding and purpura since 2 years old. On the first admission to our hospital because of hematuria at 18 years old, she was diagnosed as thrombasthenia (type II) from hemostatic studies. At 20 years old, she had a healthy baby by the cesarean section with transfusion of fresh blood and platelet concentrates. On the 5th admission for the breast tumor resection, defect of glycoprotein II b-III a of her platelets was confirmed by using SDS gel electrophoresis. Recently, there are some reports on availability of DDAVP for hemostatic control in platelet dysfunction of various etiologies as well as mild hemophilia and von Willebrand disease. So, DDAVP (0.4 microgram/kg) was used for hemostasis control. After 1 hour, the bleeding time was shortened from over 10 to 4 min, platelet adhesiveness to glass beads increased from 1.8 to 37%. Furthermore, the levels of Ristocetin cofactor and von Willebrand factor antigen (especially large multimer) also increased. But platelet aggregation with various inducers remained unchanged before and after infusion. Breast tumor (fibroadenoma) resection.

Adult↗

Successful treatment with a long-acting somatostatin analogue (SMS201-995) in a patient with malignant carcinoid syndrome.

A case of carcinoid syndrome is presented. Pulmonary adenosquamous carcinoma with hepatic metastasis was found in a 60-year-old Japanese male who was complaining of fever, cough and haemosputum. After the treatment with 5-fluorouracil (5-FU) over 2 years, he was diagnosed as carcinoid syndrome on the appearance of facial flushing, face edema and watery diarrhea accompanied by high levels of 5-hydroxyindole acetic acid (5-HIAA) in blood and urine. Prednisolone, which was initially effective, was replaced by SMS201-995 due to the considerable dose increase of the former because its effect became insufficient during the course of the treatment. Clinical symptoms were improved by SMS201-995 and blood 5-HIAA level decreased gradually but markedly. Thus better results were obtained by SMS201-995 compared with prednisolone. These results imply that SMS201-995 is appreciated as an effective drug for treatment of carcinoid syndrome.

Adenocarcinoma↗

The potentiating effect of platelet on plasminogen activation by tissue plasminogen activator.

A new role for platelets in fibrinolysis is proposed. Platelets (euglobulin from platelet rich plasma and from human platelet extract) may potentiate plasminogen activation by tissue plasminogen activator (tPA). The potentiating activity was detected by both chromogenic substrate and fibrin plate analysis. The fibrinolysis-potentiating substance in the platelets required the presence of both tPA and plasminogen, suggesting that it potentiates the activation of plasminogen by tPA. This substance was not related to fibrinogen degradation products because it was also present in platelets from two afibrinogenemic patients and did not lose its activity when separated from fibrinogen-related antigen by Sepharose 2B gel filtration. Since platelets contain both activator(s) and inhibitor(s) of plasminogen activation by tPA, a balance between activator(s) and inhibitor(s) in platelets may also be required for control of the fibrinolytic pathway.

Antigen-Antibody Complex↗