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Biomedical subjects

K Tsukada

Publications and source records attributed to K Tsukada.

At least 235 records · Page 13Linked to original sources
PubMed1989

Antitumor effect of a baker's yeast mannan-mitomycin C conjugate against mouse hepatoma, MH134, in vivo and in vitro.

A conjugate of mitomycin C and the mannan of bakers' yeast (Saccharomyces cerevisiae wild type strain) was synthesized. Assay of its growth inhibitory effect on MH134 hepatoma solid tumor implanted in C3H/He slc mice showed that this conjugate exhibited a higher growth-inhibition ratio than those of free mitomycin C and the same bakers' yeast mannan in the corresponding effective doses. This conjugate was also found to kill the same hepatoma cells in vitro. Because a dextran-mitomycin C conjugate did not manifest any antitumor effect against this tumor, it was postulated that interaction of the mannan moiety in the mannan-mitomycin C conjugate with the mannose receptor located on the cell surface of immunocytes and/or with hepatoma cells participated in the common initiating reaction of in vitro and in vivo antitumor effects.

Animals↗
PubMed1989

[A case of primary pulmonary hypertension with beneficial effect of oral long-acting prostaglandin E1 and nifedipine].

A 23-year-old female with moderate primary pulmonary hypertension (PPH) was treated by chronic oral administration of long-acting prostaglandin-E1 (PGE1) and nifedipine. Cardiac catheterization revealed evidence that both drugs had beneficial effects on this case. Total pulmonary resistance (TSR) decreased from 1089 to 955 dyne.sec.cm-5 by intravenous administration of PGE1 at a rate of 0.04 micrograms/kg/min and from 1089 to 710 dyne-sec-cm-5 by sublingual administration of nifedipine 10 mg respectively. After ten months of treatment with these two drugs, her pulmonary arterial pressure decreased from 85/40 (mean; 58) mmHg to 55/36 (mean; 45) mmHg, TSR decreased from 1089 to 829 dyne.sec.cm-5 and PaO2 in room air increased from 74.5 to 94.9 mmHg. Chest X-P and ECG revealed the decrease in the loading of the right ventricle. Thus, combined administration of PGE1 and nifedipine is expected to benefit PPH.

Administration, Oral↗
PubMed1989

The nuclear matrix from rat liver is capable of phosphorylating exogenous tyrosine-containing substrates.

The nuclear matrix isolated from rat liver phosphorylated exogenous tyrosine-containing substrates angiotensin II and synthetic polymer (Glu, Tyr; 4:1). The phosphorylation reaction was dependent on Mn2+ or Mg2+, but the former was the preferred ion. Km values for poly(Glu,Tyr; 4:1) and ATP were 0.2 mM and 4 microM, respectively. Angiotensin II showed a lower affinity for the kinase than poly(Glu,Tyr; 4:1). The isoflavone genistein, a specific inhibitor for tyrosine phosphorylation, inhibited the tyrosine kinase activity in the nuclear matrix.

Adenosine Triphosphate↗
PubMed1988

Complete purification and immunochemical analysis of S-adenosylmethionine synthetase from bovine brain.

We have purified S-adenosylmethionine (AdoMet) synthetase about 3000-fold from bovine brain extract. The Km values of the enzyme for L-methionine and ATP were 10 and 50 microM, respectively. An apparent molecular mass of the enzyme was estimated to be 160 kDa by gel filtration on a Sephacryl S-200 column. Sucrose density gradient centrifugation gave a sedimentation coefficient of 8 S. Polyacrylamide gel electrophoresis of the purified enzyme in native system revealed a single protein band, whereas two polypeptide bands with molecular masses of 48 kDa (p48) and 38 kDa (p38) were observed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme. Antibody against bovine brain AdoMet synthetase was prepared by injecting the purified enzyme into a rabbit. Immunoblot analysis revealed that the antibody recognized both p48 and p38 in the impure enzyme preparations from bovine brain as well as in the purified enzyme. Specific antibodies against p48 and p38 were separated from the immunoglobulin fraction by an affinity purification, both of which inhibited the enzyme activity. These results indicate that AdoMet synthetase from bovine brain consists of two different polypeptides, p48 and p38.

Adenosine Triphosphate↗
PubMed1988

Inferior vena caval obstruction: transvenous instrumental membranotomy.

Five transvenous instrumental membranotomies were performed in four patients with membranous obstruction of the hepatic segment of the inferior vena cava. Membranotomy was done with a specially designed instrument similar to a Tubbs' dilator, which was inserted through femoral or the right internal jugular veins. Pressure gradients across the membrane disappeared after membranotomy and the release of the stenosis was confirmed by angiography and ultrasonography. One patient needed a second membranotomy because of recurrent stenosis 7 years after the initial procedure.

Adult↗
PubMed1988

Measurement of portal blood flow by an ultrasonic "duplex" system composed of a pulsed Doppler flowmeter and a linear-type real time B mode electroscanner.

The portal vein hemodynamics of patients with various liver diseases were investigated by means of a duplex system consisting of a linear electroscanner and a pulsed Doppler flowmeter. In cases of chronic liver disease, the cross-sectional area of the portal vein trunk became greater as the liver injury proceeded, while the maximum velocity tended to decrease. However, blood flow volume was no different between the controls and the chronic liver disease group. On the other hand, the splenic venous flow volume tended to increase as the liver injury advanced, suggesting that the increase in splenic venous flow volume is closely related to the formation of esophageal varices. This method permits non-invasive observation of changes during the course of various types of liver disease.

Blood Flow Velocity↗
PubMed1988

IgA deposition in alcoholic liver disease. An immunoelectron microscopic study.

The ultrastructural localization of IgA, IgA1, and IgA2 deposited on liver tissues from 13 patients with alcoholic liver disease and 9 patients with nonalcoholic liver diseases was investigated by the immunoperoxidase method. A continuous pattern of IgA deposition along the perisinusoidal area was observed not only in the alcoholic patients but also in the nonalcoholic patients. Ultrastructurally, IgA deposits were seen on the plasma membranes of Kupffer cells, endothelial cells, and hepatocytes and in the endocytotic vesicles and phagosomes of Kupffer cells and endothelial cells. In the alcoholic group, deposits of IgA on collagen fibers were observed at sites where pericellular fibrosis developed but, on the other hand, IgA deposits were diminished or absent on the plasma membranes of hepatocytes. IgA1 showed the same deposit pattern as IgA. IgA2 was observed on and in Kupffer cells and endothelial cells but was not detected on the plasma membranes of hepatocytes. From these studies, the authors conclude that IgA deposition in the liver is not specific for alcoholic liver disease but may reflect the reduced metabolism of damaged liver. An additional finding was that, of the IgA subclasses, only IgA1 combined with the plasma membranes of hepatocytes.

Hepatitis↗
PubMed1988

Effect of ursodeoxycholate on the biliary excretion of cefotiam and sulbenicillin in patients with percutaneous transhepatic biliary drainage.

The effects of ursodeoxycholate administration on the biliary excretion of the antibiotics cefotiam and sulbenicillin were studied in five patients with stable hepatic function receiving percutaneous transhepatic biliary drainage for obstructive jaundice. Cefotiam (I g) and sulbenicillin (2 g) were administered intravenously before and after ursodeoxycholate administration, and the maximum concentrations of the antibiotics in the bile and total amounts excreted in the bile during the 4 h after administration were determined. After ursodeoxycholate administration, both the maximum concentration of cefotiam in the bile and the amount excreted increased significantly. Ursodeoxycholate also increased the peak concentration and total excretion of sulbenicillin. For both cefotiam and sulbenicillin, the amount of antibiotic excreted in the bile during the 4 h after administration showed a significant correlation with the amount of bile acids excreted in the bile. This strongly suggests a common mechanism for the biliary excretion of these antibiotics and bile acids. Ursodeoxycholate administration is a benign way to increase both the concentration and the total amount of antibiotic excreted in the bile. Therefore, it may be useful in the treatment of serious biliary tract infections, especially in patients receiving biliary drainage.

Aged↗