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Biomedical subjects

T Sakamoto

Publications and source records attributed to T Sakamoto.

At least 1,261 records · Page 70Linked to original sources
PubMed1975

Clinical significance of bradykinin liberation during cardiopulmonary bypass and its prevention by a kallikrein inhibitor.

Activation of the kinin system and effects of Trasylol (Bayer, A.G. Lebukusen, West Germany), a kallikrein inhibitor, were investigated on 52 patients during hemodilutional cardiopulmonary bypass (CPB). Immediately after the start of CPB, neither elevation of bradykinin nor reduction of plasma kininogen (KGN: a precursor of bradykinin) were observed. During CPB, bradykinin level in the blood was markedly elevated, correlating with the significant decrease of kininogen (p less than 0.001). The longer the CPB time, the more marked the reduction of KGN. In the cases requiring over 60 minutes of CPB, the amounts of bradykinin released (4.6-18.0ng/ml) were sufficient to increase capillary permeability as well as peripheral vasodilatation. As shown by the sufnificant increase of hematocrit (p less than 0.005) and the extreme reduction of vascular resistance found at the end of CPB in the prolonged cases. Infusion of Trasylol into the extracorporeal circuit actually prevented the reduction of kininogen and the increase of hematocrit as well as the extreme decrease of vascular resistance in the cases of over 60 minutes CPB. These results clearly point out that Trasylol is beneficial for the prevention of bradykinin liberation and capillary permeability increase and for the maintenance of optimum peripheral vascular tone during CPB. Furthermore, the significance of these findings with regards to complications during and after prolonged CPB was discussed.

Aprotinin↗
PubMed1975

A role of extracorporeal circuit in the post-perfusion thrombocytopenia: a scanning electronmicroscopic observation.

Thrombocytopenia is one of the adverse effects of extracorporeal circulation (ECC) but the mechanism of which has not been fully understood. Blood-gas interface, mechanical agitation, rough surface of extracorporeal circuit and sequestration in the liver have been considered to be a cause of platelet loss. Extracorporeal circuit which provides large artificial surface for contact of blood has been blamed as the site of platelet destruction during oxygenation. However, the part of the oxygenator responsible for platelet loss has bot been located. This study was designed to identify the sites of extracorporeal circuit responsible for platelet loss during ECC with scanning electron microscopy (SEM) of the post-perfusion circuit. The accumulation of platelet aggregates was most pronounced at the defoaming net and blood filter where a sudden changes in velocity of blood flow take place. The aggregates were considered to be formed locally at these sites. However, there were no accumulation and/or adherence of platelet aggregates of significant degree at the other parts of the circuit, namely venous and arterial tubings, venous colum and arterial reservoir. Platelets seem to be removed from the circulation during each passage by defoaming net and blood filter. However the other parts of the circuit seem to be less blamed for the platelet loss. It was not possible to conclude whether the formation and trapping of platelet microaggregates at the defoaming net and blood filter or the destruction by oxygen bubbles is mainly responsible for the plateletloss during ECC.

Animals↗
PubMed1975

Simplified operative technique for the long-segment atypical coarctation of the aorta.

Simplified operative technique for the long-segment atypical coarctation of the aorta was described. The main objective of this technique is to gain quick access to both thoracic and abdominal aorta with minimal blood loss, and preservation of diaphragmatic function. This procedure consists of standard thoracotomy and pararectal incision with an entry into the retroperitoneal space. Long prosthetic graft was anastomosed in an end-to-side fashion to bypass the coarctated aorta. The graft is placed through peripheral circumference of the left hemidiaphragm, where phrenic nerve injury is not likely to occur. This technique was successfully applied to two cases of long-segment atypical coarctation of the aorta due to Takayasu's aortitis. Retroperitoneal placement of the graft prevents fatal hemorrhage due to direct contact with the graft. Contamination with transintestinal exudate can also be avoided. Results of the ten-year follow-up of the similar procedure in the literature is encouraging.

Adult↗
PubMed1975

Analysis of 102 lesions diagnosed as "palatal tumor" in a spot diagnosis.

The present report analyzes 102 pathologic conditions of the palate which had been diagnosed as "palatal tumor" in a spot diagnosis at Osaka University Dental Hospital over an 8-year period. Tumors of minor salivary glands were the most frequent (51 cases, 50%). Tumors of non-salivary gland origin numbered 22 cases (21.6%), and inflammatory and cystic lesions totalled 29 cases (28.4%). The specificity of the tumors and the tumorous lesions in the palate are discussed.

Adenocarcinoma↗
PubMed1975

Protein kinase and phosphatases from human polymorphonuclear leucoytes.

Purified preparations of human polymorphonuclear leucocytes contain a protein kinase in the cytosol which is stimulated by cyclic AMP and cyclic IMP but not by other cyclic nucleotides. The holoenzyme had a molecular weight of 66000 estimated by gel filtration; when it was incubated with histone or cyclic AMP, it dissociated into two smaller subunits of molecular weight 45000 and 30000; the former remained cyclic AMP-sensitive, whereas the latter had become independent of added cyclic AMP. By means of substrate-affinity chromatography on histone-Sepharose 4B, cyclic [3H5AMP-binding activity (regulatory or R subunit) could be resolved into two peaks of enzyme activity, one again independent of added cyclic AMP, with a molecular weight of 30000 (catalytic or C subunit). Also by means of substrate-affinity chromatography it was possible to resolve 'specific' polymorphonuclear leukocyte histone phosphatases from 'non-specific' phosphomonesterases capable of dephosphorylating histone previously phosphorylated by the protein kinase. Specific histone phosphatase displayed greatest affinity for histone-Sepharose 4B, followed by acid p-nitrophenyl phosphatase, and the unretained acid beta-glucerophosphatase. Polymorphonuclear leucocyte histone phosphatase, purified approx. 40-fold, was further resolved from the other phosphatases by gel filtration on Sephadex G-150 from which it was eluted with apparent molecular weights of 45000 and 18700. The apparent Km values for dephosphorylation of histone are 4.3 X 10-6M and 3.6 X 10-6M. Most (69%) of cytoplasmic histone phosphatase was found in the cell sap, whereas 20% remained tightly associated with polymorphonuclear leucocyte lysosomes from which it could not be solubilized by treatments (Triton X-100, freeze-thawing) that released approx. 70% of lysosomal beta-glucuronidase or acid phosphatases. Although both soluble and particulate enzymes required 5-10 mM-Mn2 for maximal activation, and showed a pH maximum of 6.5-7.0, only the particulate enzyme was partly inhibited by ammonium molybdate. Polymorphonuclear leucocyte histone phosphatases were neither inhibited nor stimulated by those cyclic nucleotides that greatly stimulate the protein kinase of the same subcellular fraction

Acid Phosphatase↗
PubMed1975

Radiation therapy of brain tumors in children.

The case histories of 124 children irradiated for brain tumors were reviewed to determine survival rate and functional prognosis, with special reference to somatic growth. Five-year survival rates (29% of 97 patients with gliomas and 70% of 27 patients with non-gliomatous tumors) were approximately the same as in our adult series, despite the differences in histology and predilection. Although 70% of 42 long-term survivors had active, useful lives, stunted growth was observed in 15 of them. More attention should be directed to the growth of children irradiated for brain tumors.

Adolescent↗
PubMed1975

Echocardiogram and phonocardiogram related to the movement of the pulmonary valve.

Pulmonary valve movement and the related acoustic phenomena were investigated using high speed strip-chart echo- and phonocardiographic recording. The opening of the pulmonary valve had no definite relationship to the acoustic phenomena, whereas the pulmonary ejection sound was closely related in time to the early systolic maximal opening of the valve. The concomitant pulmonary ejection systolic murmur faded away by the time of the mid-systolic semi-closure of the valve, where the tiny extrasound occurred in a half of cases. The pulmonary component of the second heart sound occurred after the valve closure, and the time lag maximally reached up to 50 msec. Pulmonary hypertension tended to minimize this delay, giving the so-called single loud second heart sound. Graham Steell murmur started with the pulmonary component of the second heart sound and reached up to the isometric contaction phase beyond the first heart sound.

Adult↗
PubMed1975

The effect of bithionol sulphoxide on Echinococcus granulosus and Taenia hydatigena infections in dogs.

Trials with bithionol sulphoxide involving 130 dogs, infected with either Echinococcus granulosus or Taenia hydatigena, indicated that a single treatment at a dose rate of 400 mg/kg or two treatments at 50 mg/kg eliminated the former, but a single treatment at 50 mg/kg was sufficient to eliminate the latter. Dose rates 200 mg/kg or more were lethal to some dogs. With two doses of 50 mg/kg, there was only minor discomfort from vomiting or diarrhoea in some dogs.

Animals↗