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Biomedical subjects

T Oda

Publications and source records attributed to T Oda.

At least 613 records · Page 34Linked to original sources
PubMed1986

Stimulation of macrophage by polyanions and its conjugated proteins and effect on cell membrane.

Lipophilic anionic copolymer (styrene-maleic acid; SMA) conjugates of albumin and antitumor protein neocarzinostatin (NCS) (smancs) were found to stimulate the release of H2O2 and O-2 from the peritoneal macrophages obtained from mice which had been pretreated with the heat-killed preparation of Streptococcus pyogenes (OK-432) in vivo. Some alkyl esters of SMA exhibited effects similar to protein-polymer conjugates. Among them, butyl-SMA was the most effective followed by ethyl-SMA, whereas hydrolyzed SMA showed no effect. This activity was dose-dependent but exhibited a bell-shape profile. These results suggest that the aliphatic ester residue in SMA as well as the main chain of the copolymer may be important for the activation of macrophages. A strong antitumor effect of smancs reported elsewhere may be attributed partly to the activation of macrophages in addition to the direct damage to the cellular DNA by the NCS component. A preliminary investigation of the subcellular mechanism of macrophage activation was carried out in view of membrane fluidity by the fluorescence polarization method. The results showed that the apparent decrease in the cell membrane fluidity and the degree of macrophage activation paralleled the same dose range and at similar time courses. This indicated the interaction of SMA component and macrophage cell membrane.

Animals↗
PubMed1986

Transmission of non-A, non-B hepatitis agent to chimpanzees from patients of epidemic hepatitis.

Two chimpanzees were inoculated intravenously with acute-phase sera obtained from two patients with epidemic hepatitis. They developed histopathologically confirmed hepatitis. Electron microscopic examination of the liver showed peculiar cytoplasmic tubular structures in the hepatocytes. These ultrastructural findings were similar to those described for the livers of chimpanzees inoculated with the F strain of non-A, non-B hepatitis agent derived from a posttransfusion hepatitis case. The chimpanzee that had recovered from hepatitis caused by the F strain of non-A, non-B hepatitis agent was re-challenged with the serum from one of the patients. The chimpanzee developed neither clinical signs nor histological changes of hepatitis. These results suggested that non-A, non-B hepatitis agent was involved not only in post-transfusion hepatitis but also in epidemic hepatitis.

Animals↗
PubMed1986

[Periarteritis nodosa of the epididymis].

A thirty-one-year-old man with a scrotal swelling on the left side was found to have periarteritis nodosa of the epididymis (epididymal arteries). No systemic symptoms were present. Review of the literature revealed only two similar cases.

Adult↗
PubMed1986

Malotilate (diisopropyl 1,3-dithiol-2-ylidenemalonate) increases liver de novo purine synthesis and amidophosphoribosyltransferase activity.

The effect of malotilate (diisopropyl 1,3-dithiol-2-ylidenemalonate) on de novo purine synthesis was studied in rat liver in vivo and in primary cultured rat hepatocytes in vitro. In the in vivo system, malotilate increased [14C]glycine incorporation by 1.4- to 1.7-fold into acid soluble hepatic purines 4 to 18 hr and the rapidly miscible glycine pool size at least by 2.0-fold 12 hr after administration. Malotilate did not change 5-phosphoribosyl-1-pyrophosphate concentration but increased significantly amidophosphoribosyltransferase (E.C. 2.1.2.14) activity per unit of DNA or per unit of liver protein. Malotilate also increased significantly the hepatic cyclic AMP concentration 2 to 12 hr after administration. In the in vitro system, malotilate increased [14C] formate incorporation into acid soluble purines with accompanying increases in 5-phosphoribosyl-1-pyrophosphate availability and the specific activity of amidophosphoribosyltransferase. These results suggest that malotilate increases the rate of de novo purine synthesis in the liver by its direct action on hepatocytes, the mechanism of this increase is due to the combined increase of amidophosphoribosyltransferase activity and 5-phosphoribosyl-1-pyrophosphate supply and cyclic AMP may play a role for this response.

Adenosine Triphosphatases↗
PubMed1986

[Stability of high molecular weight anticancer agent SMANCS and its transfer from oil-phase to water-phase. Comparative study with neocarzinostatin].

SMANCS is a conjugate protein of copolymer of styrene-maleic acid [SMA] (molecular weight: 1,500) and an antitumor protein neocarzinostatin [NCS] (molecular weight: 11,700). It has an approximate molecular weight of 15,000. We report here stability of SMANCS in oil and in water, and NCS in water, under various physical conditions such as exposure to heat, UV, pH, and ultrasonic treatment. Then, we carried out an experiment of transfer of SMANCS in lipid contrast medium [lipiodol] (oil phase) to water phase (blood and physiological saline) in vitro. Results are summarized as follows: In aqueous condition, SMANCS is far more stable than NCS against the exposure to heat and UV, though it is inactivated by excessive exposures. SMANCS in an oily medium was found much more stable even at higher temperatures than in the aqueous phase. Both SMANCS and NCS are the most stable at pH 4.9-6.0. SMANCS dissolved in oil transferred to water phase slowly, having T1/10 of 24 hours (in case of lipiodol). This helps maintaining the anticancer effect of the drug in vivo for a long period of time. SMANCS in lipiodol was found to exert its action against cultured tumor cells as in an aqueous solution.

Antibiotics, Antineoplastic↗
PubMed1986

Molecular cloning of cDNA for argininosuccinate lyase of rat liver.

A cDNA expression library constructed from poly(A)+ RNA of rat liver was screened immunologically using an antibody against argininosuccinate lyase (EC 4.3.2.1), a urea cycle enzyme, of rat liver. A cDNA clone was isolated and identified by hybrid-selected translation. The clone contained an insert approximately 1.5 kilobase pairs in length. In the bacterial clone, a specific protein of Mr = about 25,000 was expressed. The argininosuccinate lyase mRNA of about 2.1 kilobases long was detected in the liver and in a lesser amount in the kidney and spleen, but not in the small intestine and heart of the rats.

Animals↗
PubMed1986

Serum thyroid hormone, triiodothyronine, thyroxine, and triiodothyronine/thyroxine ratio in patients with fulminant, acute, and chronic hepatitis.

The concentrations of triiodothyronine (T3), thyroxine (T4), T3/T4 ratio, free thyroxine index, and thyroxine-binding globulin were investigated in 114 viral hepatic disease patients and 36 controls. The T3/T4 ratio in healthy hepatitis B virus carriers was significantly greater than those in the controls and fulminant, acute, or chronic active hepatitis patients. The T3/T4 ratio in the fulminant hepatitis patients was significantly less than those in the controls and other liver disease patients. The correlation coefficient between the T3/T4 ratio and microsomal arylamidase activity in liver tissue from 30 patients was 0.78 (p less than 0.001). The correlation coefficient between the T3/T4 ratio and the content of cholinesterase was 0.64 (p less than 0.001). These results suggest that the T3/T4 ratio represents a marker of microsomal function and is useful for estimation of prognosis of fulminant hepatitis or differentiation of various viral hepatic diseases.

Acute Disease↗
PubMed1986

[Two cases of carcinoid tumor of the stomach and a collective review of the Japanese literature].

We report two cases of carcinoid tumor of the stomach together with a collective review of the Japanese literature. Case 1 was preoperatively diagnosed as carcinoid, and the lesion, measuring 10 X 7 mm, and located in the body of the stomach, had no metastases. Case 2 was preoperatively diagnosed as gastric cancer and was recognized as a submucosal tumor measuring 5.8 X 4.7 cm in the antrum of the stomach. There were metastases to the brain and the skin, and the patient died on the 50th day after the operation. From a collective review of previous cases, it was ascertained that small carcinoid tumors sometimes had metastases. For this reason, we feel gastrectomy should be performed together with local lymph node resection.

Carcinoid Tumor↗
PubMed1985

Biological properties of griseolic acid, a cyclic AMP phosphodiesterase inhibitor with an adenine group.

Griseolic acid inhibited cAMP phosphodiesterase (PDE) at low concentrations, the I50 being of the order of 0.01-0.1 microM. Administration of griseolic acid to rats increased the cAMP level in liver and plasma several-fold. It increased glycogen degradation in mouse liver and stimulated lipolysis in isolated rat fat cells. Griseolic acid did not block the adenosine-elicited accumulation of cAMP in guinea pig brain slices. It had no effect on cAMP-dependent protein kinase from rat liver nor on the adenyl cyclase from rat brain.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1985

Cloning and expression in Escherichia coli of cDNA for serine: pyruvate aminotransferase of rat liver.

Cloned cDNAs for rat liver serine: pyruvate aminotransferase were obtained by screening of a cDNA expression bank of rat liver with an antibody against the enzyme. Nineteen clones were isolated from 33 000 transformants and most of them had common fragments of cDNA on analysis by digestion with some restriction enzymes. These clones were identified as those containing cDNA for serine:pyruvate aminotransferase by the following criteria. (a) At the nucleic acid level, a 500-base-pair fragment of cDNA prepared by digestion of cDNAs with EcoRI and PstI hybridized with the mRNA coding for serine:pyruvate aminotransferase as judged by hybrid-selected and hybrid-arrested translations. (b) Specific proteins were detected in nine bacterial clones, a 40-kDa protein in one clone and a 39-kDa protein in eight clones. Among them only the 40-kDa protein was found to be solubilized from the cell by sonication, and this protein was immunoprecipitated with an antibody against serine:pyruvate aminotransferase of rat liver. (c) High activity of serine:pyruvate aminotransferase was expressed both in whole cell suspension and sonicated extract prepared from the transformant producing the 40-kDa protein, and 99% of the activity was immunoreactive with the antibody. Two types of mRNA for serine:pyruvate aminotransferase were detected on the RNA blot analysis by using cloned cDNA fragment as a probe. The larger mRNA (approximately 1600 nucleotides) was glucagon-inducible while the smaller one (approximately 1500 nucleotides) was not affected by the hormone.

Animals↗
PubMed1985

Effect of dextran sulfate on the survival time and mitochondrial function of Adriamycin (doxorubicin)-treated mice.

The effect of dextran sulfate on the survival time and mitochondrial function of adriamycin (ADM)-treated mice was studied. ADM-induced toxicity in mice was reduced by treatment with dextran sulfate (60, 100, 300, and 600 mg/kg, sc). The optimum dextran sulfate dose for protection against ADM-induced toxicity in mice was about 200 mg/kg/day (sc) and 100 mg/kg/day (po). Groups treated with dextran sulfate (300 mg/kg) had significantly improved mitochondrial function as measured by oxygen uptake of state 3 (p less than 0.01), dinitrophenol-altered respiration (p less than 0.01), and respiratory control index level (p less than 0.01). From these observations, it was concluded that ADM-induced toxicity due to reduced mitochondrial function can be ameliorated by the membrane stabilizing effect of dextran sulfate.

Administration, Oral↗
PubMed1985

Immunocytochemical demonstration of serine: pyruvate amino-transferase in peroxisomes and mitochondria of rat kidney.

The light- and electron-microscopic localization of serine: pyruvate aminotransferase (SPT) in rat kidney was studied using immunoenzyme and protein A-gold techniques. Rat kidneys were fixed by perfusion through the abdominal aorta and small tissue slices were embedded in Epon, Lowicryl K4M, or LR Gold. The Epon was removed from the semithin sections, which were then stained using the immunoenzyme technique. Ultrathin sections of Lowicryl K4M- or LR gold-embedded materials were labeled using the protein A-gold technique. At light microscopy, discrete granular reaction deposits were exclusively present in the proximal tubule, all of whose segments were positive for SPT. A weakly positive reaction was observed in the distal tubules. At electron microscopy, gold particles indicating the antigenic sites for SPT were confined to the peroxisomes and mitochondria. The labeling intensity of both organelles was dependent on the embedding resins used. The labeling of Lowicryl K4M-embedded material was weaker than that of LR gold-embedded material; Quantitative analysis confirmed this result. Our results indicate that, in rat kidney, the main intracellular sites for SPT are peroxisomes and mitochondria of the proximal tubule.

Animals↗
PubMed1985

Silver staining for selective detection of histones in polyacrylamide gels.

A simple silver-staining technique was developed for selective visualization of histones in polyacrylamide gels. The specificity of the stain was confirmed using a variety of protein mixtures and isolated histones. The staining procedure requires a relatively short time to perform (2.5-3 h), and the sensitivity to lysine-rich histones is comparable to that of the conventional Coomassie blue stain (about 0.1 microgram per band). A possible mechanism for the selective staining was deduced from a comparison with the widely used ultrasensitive silver staining.

Chemical Phenomena↗