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Biomedical subjects

K Takada

Publications and source records attributed to K Takada.

At least 937 records · Page 52Linked to original sources
PubMed1980

Hypoglycemia in a child with hepatoblastoma.

A five-year-old boy with hepatoblastoma, who showed a severe hypoglycemia as an initial symptom, was studied. After resection of tumors, hypoglycemia disappeared and did not recur despite recurrence of tumor. A high concentration of insulin-like activity (ILA) was found in preoperative serum and in the tumor extract. Hypoglycemia in this patient seemed to depend mainly on ILA and in part on liver enzyme activities related to carbohydrate metabolism.

Carcinoma, Hepatocellular↗
PubMed1980

I-Naphthyl acetate esterase isoenzymes in synovial fluids and radiography of temporomandibular and knee joints.

Esterase isoenzymes of synovial fluids were presented in cases of pain-dysfunction syndrome, osteoarthrosis, osteochondroma, malignant fibrous histiocytoma of temporomandibular joint, and hemarthrosis, rheumatoid arthritis of the knee joint. Radiographic features of them were also comparatively presented in several cases. The electrophoretogram of I-Naphthyl acetate esterase of pain-dysfunction syndrome showed the esterase-I, while when inflammatory process developed at joints, electrophoretic pattern of synovial fluids revealed a rather similar feature of sera with variable stainabilities of esterase-I, and -III, irrespective of any inflammation. Osteochondroma showed two components of esterase-I and -III, on the other hand malignant fibrous histiocytoma presented esterase-I and -III in the early stage but a more complicated pattern in recurrence. Among these conditions, the most similarity between synovial fluid and serum was demonstrated in the case of hemarthrosis on the electrophoretogram of I-Naphthyl acetate esterases.

Adult↗
PubMed1980

Analysis of the transformation of human lymphocytes by Epstein-Barr virus. II. Abortive response of leukemic cells to the transforming virus.

Leukemic lymphocytes with B-cell markers were obtained from the peripheral blood of 4 patients with chronic lymphocytic leukemia (CLL) or acute lymphocytic leukemia (ALL); a significant number of T cells was not involved. The lymphocytes were inoculated with the transforming B95-8 Epstein-Barr virus (EBV). Synthesis of EBV-determined nuclear antigen (EBNA) occurred in three CLL preparations: 15.1--25.4% of cells expressed maximum EBNA 24--48 h after viral exposure. A characteristic immunofluorescence pattern similar to a coarsely clumped chromatin structure was observed. In contrast to EBV infection of normal lymphocytes, EBNA synthesis in CLL cells (morphologically similar to normal lymphocytes) was not followed by either blastogenesis or DNA synthesis. EBNA-positive cells, which usually degenerate within 1--2 weeks, could be maintained for more than 30 days on feeder human embryo fibroblasts pretreated with mitomycin C. DNA synthesis and mitosis occurred, but unlimited cell growth did not. 41.9% of ALL cells were EBNA-positive at 36 h prior to DNA synthesis, and they subsequently grew rapidly for up to 9 days. The cell proliferation, however, was temporary, and death resulted in about 2 weeks. No significant synthesis of EBV-related early antigens and viral capsid antigen was noted in any of the infected cultures throughout the incubation period. These results indicate that certain intracellular restrictions may have exceeded the potent transforming capacity of EBV in these target leukemic cells.

Antigens, Viral↗
PubMed1980

[Studies on transformation of human lymphocytes by Epstein-Barr virus (author's transl)].

A simple method for simultaneous comparative observations of immunofluorescence, cellular morphology and autoradiography has been developed, and this method was applied to investigate the early transformation events of human cord blood lymphocytes by Epstein-Barr virus (EBV). The results indicated that transformation occurred sequentially from EBV-determined nuclear antigen (EBNA) synthesis, to blastogenesis, to DNA synthesis, and consistently resulted in unlimited growth of the antigen-positive lymphoblasts. EBNA synthesis was not hampered in the presence of Ara C, but was significantly inhibited by a short-term exposure to cycloheximide immediately after EBV infection. The response of leukemic cells to EBV was further studied. Only leukemic lymphocytes with B-cell markers showed susceptibility to EBV, in close connection with the presence of complement receptor. In contrast to EBV infection of normal B-lymphocytes, EBNA synthesis in three chronic lymphocytic leukemia (CLL) preparations was not followed by either blastogenesis or DNA synthesis and the infected cells shortly resulted in cell degeneration. In case of acute lymphocytic leukemia (ALL), EBNA-positive cells were highly evident and grew rapidly for up to 9 days. The cell proliferation, however, was temporary and death resulted in about 2 weeks. No significant synthesis of EBV-related early antigens and viral capsid antigen was noted in any of the infected culture throughout the incubation period.

Adult↗
PubMed1980

New fluorogenic peptide substrates for plasmin.

Fluorogenic peptides, peptidyl-4-methylcoumaryl-7-amides (MCA), containing COOH-terminal lysine residues, were newly synthesized and tested as substrates for plasmin. Among six peptidyl-MCA's, Boc-Val-Leu-Lys-MCA and Boc-Glu-Lys-Lys-MCA were found to be useful for the specific and sensitive assay of plasmin. The Km values estimated from Line-weaver-Burk plots for these substrates using human and bovine plasmins were in the region of 10(-4) M. Boc-Glu-Lys-Lys-MCA was slightly hydrolyzed by bovine plasma kallikrein, and Boc-Val-Leu-Lys-MCA was slightly hydrolyzed by human and hog urinary kallikreins and hog pancreatic kallikrein. However, both of the fluorogenic peptides were essentially unaffected by urokinase, alpha-thrombin, Factor Xa, Factor IXa, Factor XIa, and Factor XIIa. It was confirmed that plasmin hydrolyzed Boc-Glu-Lys-Lys-MCA, cleaving the lysyl-MCA bond, but not the lysyl-lysyl bond. These fluorogenic peptides were resistant to human plasmin activated by streptokinase. Boc-Glu-Lys-Lys-MCA was not hydrolyzed by human plasmin or plasminogen in the presence of more than a 5-fold molar excess of streptokinase. The sensitivity of Boc-Val-Leu-Lys- of more than a 5-fold molar excess of streptokinase. The sensitivity of Boc-Val-Leu-Lys-MCA to human plasmin was also reduced, but plasmin retained 35% of the maximum activity even in the presence of a 20-fold molar excess of streptokinase. These results suggest that streptokinase-plasmin complex has essentially no activity towards Boc-Glu-Lys-Lys-MCA.

Animals↗
PubMed1980

A new fluorogenic substrate method for the estimation of kallikrein in urine.

Kallikrein in human urine was measured using a fluorogenic peptide substrate, proly-phenyl-alanyl-arginine-4-methylcoumaryl-7-amide (Pro-Phe-Arg-MCA). Using 20 microliters of normal urine, kallikrein activity was quantitatively assayed by incubation with a final concentration of 10(-4) M Pro-Phe-Arg-MCA at 37 degrees C for 90 min. The reaction was terminated by adding 50 units of Trasylolr or 20 microliters of 10% acetic acid. Using this method, kallikrein activity was measured in urine from normal subjects and patients with glomerulonephitis and Bartter's syndrome. These values were comparable with the values obtained by radioimmunoassay using bovine low-molecular-weight kininogen. When normal urine was applied to a column of arginine-Sepharose 4B, two activities, Pro-Phe-Arg-MCA hydrolyzing activity and kinin-releasing activity toward bovine low-molecular-weight kininogen, were eluted in the same fraction. These results indicate that the present method is useful for the estimation of kallikrein in urine, in terms of specificity, sensitivity, and simplicity.

Acetates↗
PubMed1979

Comparative pharmacokinetics of coumarin anticoagulants XLIII: Concentration-dependent hepatic uptake of warfarin in rats.

The purpose of this study was to determine if hepatic warfarin uptake, which has a major quantitative effect on warfarin distribution in rats, is concentration dependent. Adult male rats received either 0.1 or 1.0 mg of racemic warfarin/kg iv and were killed 6 hr later. With increasing dose, the concentrations of free and total (free plus protein-bound) serum warfarin increased much more than proportionally, and the total warfarin concentration in the liver increased much less than proportionally. The liver to serum total warfarin concentration ratios 6 hr after injection of the 0.1- and 1.0-mg/kg doses were 11.3 +/- 1.7 and 0.814 +/- 0.222, respectively (mean +/- SD, n = 6, p less than 0.001). The ratio of the total drug concentration in the liver to the free drug concentration in serum (mean +/- SD) was 866 +/- 105 in animals that received the 0.1-mg/kg dose and 111 +/- 42 in animals that received the 1.0-mg/kg dose (p less than 0.001). It is concluded that hepatic warfarin uptake decreases with increasing drug concentration and that this may cause the apparent volume of distribution of warfarin to decrease with increasing dose in rats.

Animals↗