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Biomedical subjects

M Nishida

Publications and source records attributed to M Nishida.

At least 487 records · Page 27Linked to original sources

[Mechanisms of the antitumor action of gestagens on endometrial cancer].

An attempt was made to elucidate the relationship between the progestational activities and antitumor effects of various steroid hormones in vitro and in vivo. The established cell line (Ishikawa cells) of a human endometrial adenocarcinoma bearing estrogen and progesterone receptors was used in this study. Sixteen kinds of steroid hormones including progesterone, medroxyprogesterone acetate (MPA) and danazol were used in vitro. Each hormone was administered at 20 micrograms/ml continuously from the 4th day of culture and the growth curve was evaluated. The effects of progesterone, MPA and danazol at a dosage of 24 mg/kg/day for 53 days on the tumor induced in athymic nude mice with Ishikawa cells were also evaluated. Three kinds of hormones, progesterone, 16 alpha-methylprogesterone and danazol revealed cytocidal effects on the cells in vitro. There was no relationship between the progestational activity and cytocidal effect of each steroid hormone. On the other hand, no significant tumor regression was observed in vivo, but progesterone and danazol showed a tendency to suppress the growth of the tumor. These results suggest that the cytotoxic properties of progesterone may play a more important role than progestational action the cytocidal effect in vitro. It has been known that MPA had antitumor effects on DMBA-induced mammary cancer in rat and human endometrial cancer. However, MPA did not show a significant antitumor effect either in vitro or against the transplanted tumor in this study. Therefore, it was suggested that the antitumor effect of MPA is not direct action on the tumor cells, but indirect action through the interstitial cells of the target organ.

Adenocarcinoma↗

Primary structure of single-chain pro-urokinase.

Single-chain pro-urokinase is an inactive proenzyme form of human urokinase with a single-chain structure and a Mr of 50,000 and converted to the active two-chain form by catalytic amounts of plasmin. It was isolated from culture fluid of human kidney cells and subjected to chemical (CNBr) and proteolytic (lysyl endopeptidase) degradation. The resulting peptides were separated by reverse-phase high performance liquid chromatography and subjected to automated sequence analysis. Amino acid sequence of 85% of the 411 residues recovered in 17 peptides were found to be consistent with those of the A chain (157 amino acids) and B chain (253 amino acids) of human urokinase reported by Günzler and co-workers (Günzler, W. A., Steffens, G.J., Otting, F., Kim, S.-M., A., Frankus, E., and Flohé, L. (1982) Hoppe-Seyler's Z. Physiol. Chem. 363, 133-141; 1155-1165; Steffens, G.J., Günzler, W.A., Otting, F., Frankus, E., and Flohé, L. (1982) Hoppe-Seyler's Z. Physiol. Chem. 363, 1043-1058). It revealed the presence of Lys at position 158 in single-chain pro-urokinase through which the two polypeptide chains of human urokinase are unified into one molecule. In addition, firm evidence was found that upon activation by plasmin single-chain pro-urokinase is cleaved at the Lys-Ile bond between residues 158 and 159, resulting in the formation of a two-chain urokinase molecule held together by one disulfide linkage. These results indicate that the cleavage at the Lys-Ile bond between residues 158 and 159 is responsible for conformational change, appearance of enzyme activity and reduction of its high affinity for fibrin.

Amino Acid Sequence↗

Proteolytic cleavage of single-chain pro-urokinase induces conformational change which follows activation of the zymogen and reduction of its high affinity for fibrin.

A plasminogen activator secreted from human kidney cells was highly purified by affinity chromatography on an anti-urokinase IgG-Sepharose column. The purified plasminogen activator was inactive and had a single-chain structure and a Mr of 50,000. It not only did not incorporate diisopropyl fluorophosphate, which reacts with active site serine residue in urokinase, but also did not bind to p-aminobenzamidine-immobilized CH-Sepharose, to which urokinase bind via its side-chain binding pocket present in active center. The plasminogen activator was converted to the active two-chain form with the same Mr by catalytic amounts of plasmin. Its potential enzymatic activity was quenched completely by anti-urokinase IgG, but not by anti-tissue plasminogen activator Ig. These results indicate that the plasminogen activator is an inactive proenzyme form of human urokinase. Therefore, the plasminogen activator was termed single-chain pro-urokinase. The cleavage of single-chain pro-urokinase by plasmin induced conformational change which followed the generation of reactive serine residue at active site, the increase enzyme activity and the reduction of its high affinity for fibrin. These findings suggest that conformational change occurs in both regions responsible for enzyme activity and affinity for fibrin upon activation of single-chain pro-urokinase.

Antibodies↗

Partition of divalent and total manganese in organs and subcellular organelles of MnCl2-treated rats studied by ESR and neutron activation analysis.

The possibility that Mn2+ is converted to other valency states in vivo was examined by measuring the ratio of Mn2+, determined by ESR, to total manganese, determined by neutron activation analysis combined with chemical separation, in various organs of control rats and rats treated with MnCl2. In control rats, the total manganese content was high in the thyroid, hypophysis, adrenal, pancreas, liver and kidney, but the Mn2+ contents of these organs were low. In rats treated with Mn2+, the total manganese contents of all organs increased, but the Mn2+ contents still remained low. With regard to subcellular distribution, the total manganese content was high in the nuclear and mitochondrial fractions of the liver and kidney, and in the microsomal and supernatant fractions of the pancreas. The ratio of Mn2+ to total manganese was relatively high in the microsomes of the liver and kidney of control rats, and in the nuclear fraction of the pancreas of Mn2+-treated rats. Thus, the distribution and behavior of manganese in the pancreas were different from those in other organs. Purified liver nuclei and mitochondria were demonstrated to contain manganese, indicating that manganese is tightly bound in each cellular compartment.

Animals↗

A macrophage activating factor is present and active in the ascitic fluid of patients with ovarian cancer.

Morphological and functional changes in human monocytes and peritoneal macrophages from six patients with ovarian cancer were studied. The surface architecture of exudate macrophages from ascitic fluid have already been shown to exhibit extensive spreading and ruffled membranes. Consequently, peripheral monocytes from the patients were cultured with ascitic fluid from the same individuals. They gradually displayed active membrane pseudopodia, thorn-like processes and petal-like ruffles after 2 h to 4 h of cultivation. Adherent peritoneal macrophages from the patients demonstrated increased consumption of glucose. These results suggest a macrophage activating factor (MAF) exists in ascitic fluid in patients with ovarian cancer which plays an initial role in the change of monocytes into macrophages.

Adult↗

Molecular cloning of cDNA coding for human preprourokinase.

A cDNA library was constructed in pBR322 from 18S to 20S mRNA that was extracted from human kidney cells, fractionated on oligo(dT)-cellulose column and sucrose-density gradient, and confirmed for urokinase production in Xenopus laevis oocytes. The Escherichia coli RR1 transformants were hybridized to synthetic oligonucleotide probe prepared according to the known amino acid sequence, Glu 73 to Glu 77 of human urinary urokinase chain B. The entire cloned cDNA covers a 2250-bp region, wherein the 1293-bp sequence codes for preprourokinase consisting of 431 amino acids, with the first 20 residues being a signal peptide. The 5'-untranslated region is at least 80 bp long and the 3'-untranslated region is longer than 850 bp.

Amino Acid Sequence↗

Histological changes occurring in the contralateral testes of prepubertal rats subjected to various durations of unilateral spermatic cord torsion.

Prepubertal rats were exposed to unilateral spermatic cord torsion for 0, 1, 3, 5, 9 or 12 hours duration. At the end of this time the damaged testes were either removed or untwisted and pexed into place. The animals were then allowed to mature to 77 days of age at which time the contralateral testes were examined for 12 histological parameters and scored according to the degree of pathology noted in each. Pathological changes in the contralateral testes were found to be dependent on the duration of spermatic cord torsion but were less severe in the orchiectomized group. Thus, removal of the damaged organ minimized the long-term damage to the contralateral testes. We also noted that specific histological parameters of the contralateral testes correlated well with fertility and that specific changes in the ipsilateral testes predicted contralateral pathology.

Animals↗

A case of polymyositis associated with Kawasaki disease.

We report a 3-year-old boy with proximal painful muscle weakness associated with Kawasaki disease. The muscle biopsy revealed inflammatory cell infiltration with vasculopathy. This unique coexistence of polymyositis and Kawasaki disease is quite uncommon and suggests a newly recognized complication during Kawasaki disease.

Biopsy, Needle↗

Prevention of perinatal transmission of hepatitis B virus (HBV) to children of e antigen-positive HBV carrier mothers by hepatitis B immune globulin and HBV vaccine.

The efficacy of hepatitis B immune globulin (HBIG) with two hepatitis B virus (HBV) vaccines was investigated for prevention of vertical transmission of HBV to infants born to e antigen-positive HBV carrier mothers. Infants received 150 mg of the F(ab')2 fraction of HBIG intravenously within 2 hr of delivery, and serum titers of antibody to hepatitis B surface antigen (anti-HBs) were kept greater than 1:4 (passive hemagglutination) by subcutaneous injection of HBIG thereafter. HBV vaccine was started three or six months after delivery. Of 50 infants older than nine months, 49 were actively immunized against hepatitis B surface antigen. Vaccine containing alum adjuvant immunized the infants in a shorter period than did vaccine without adjuvant. Serum titers of anti-HBs of actively immunized infants were well maintained afterward. None of the infants treated with HBIG and HBV vaccine was positive for serum antibody to hepatitis B core antigen at 12 months of age. No side effects were observed.

Adult↗

Thrombolytic properties of an inactive proenzyme form of human urokinase secreted from human kidney cells.

The relative fibrin-binding, fibrinolytic and fibrinogenolytic properties of single-chain pro-urokinase, an inactive proenzyme form of human urokinase purified from cultured human kidney cells, and urokinase were compared. The affinity of single-chain pro-urokinase for fibrin was much higher than that of urokinase. In Vitro thrombolytic studies showed that single-chain pro-urokinase is approximately three times more potent in fibrinolysis than urokinase and that it does not degrade fibrinogen in the plasma at a concentration, at which complete plasma clot lysis takes place; whereas, urokinase extensively degrades the fibrinogen in the plasma. These specific, potent thrombolytic properties of single-chain pro-urokinase seem to be due to its high affinity for fibrin and to its conversion from the inactive single-chain form to the active two-chain form on the thrombus by the catalytic amount of plasmin generated during coagulation. This single-chain pro-urokinase obtained from human kidney cells by tissue culture should prove advantageous than urokinase in thrombolytic therapy.

Autoradiography↗

Manganese ion as a goitrogen in the female mouse.

Effect of excessive ingestion of manganese (Mn) on the mouse thyroid was assessed under the conditions of normal intake of iodide. Female mouse thyroids were enlarged after 7 weeks of administration of 200 mg/l MnCl2 X 4H2O in drinking water; 2.74 +/- 0.25 mg for control (N = 56), and 3.31 +/- 0.28 mg for Mn-treated group (N = 85) (p less than 0.001). In contrast, male mouse thyroids never became goitrous following this treatment. Manganese was goitrogenic to the castrated male mouse, but it had no effect on the testosterone-treated castrated male mouse, indicating the involvement of androgen in goiter formation. Oral administration of Mn did not severely affect blocked T/S of 125I or iodine metabolism in the thyroid. A morphological study, however, revealed that the epithelial cell in the Mn-treated mouse thyroid became flatter than that of the control. The lumens were filed with colloid in Mn-treated female mouse thyroid. The serum levels of thyroxine (T4), but not triiodothyronine (T3), were slightly reduced by Mn. These informations suggest that Mn can be a mild goitrogen for the female mouse and that the etiology of goiter formation can be interpreted by retention of colloid in the lumen.

Animals↗