Production and characterization of a monoclonal antibody against the beta-subunit of bullfrog lutropin.

We generated a high-affinity and highly specific monoclonal antibody (BL4B11)-producing hybridoma against bullfrog lutropin (LH) beta by fusing mouse myeloma, X63.Ag8.653, with spleen lymphocytes obtained from BALB/c mice immunized with bullfrog LH-IV (pI 9.

Improved method for purification of Xenopus laevis vitellogenin and demonstration of cross-reactivity among wide-range species by radioimmunoassay.

This study was performed to improve the purification of Xenopus vitellogenin and establish the radioimmunoassay. The procedure of purification consisted of ammonium precipitation, DEAE-Sephadex chromatography and Sephadex G-200 gel chromatography. Using this procedure, 934 mg vitellogenin was purified from 49 ml of estradiol treated female Xenopus plasma (about 19 mg/ml).

[Coronary thrombolysis in acute myocardial infarction].

The effect of early perfusion after intracoronary infusion of urokinase (PTCR) in patients with acute myocardial infarction was assessed. Coronary perfusion was reestablished in 7 of 10 patients receiving intracoronary urokinase. We compared the recanalized group after intracoronary urokinase (n = 7) with the standard therapy group (n = 32).

Isolation and characterization of multiple components of basic gonadotropin from bullfrog (Rana catesbeiana) pituitary gland.

Four gonadotropin components were purified from the basic protein fraction of bullfrog pituitary glands. All the components had high potencies not only in the ovulation assay using Xenopus laevis ovaries but also in the competitive binding assay for rat follicle-stimulating hormone (FSH) using Xenopus laevis testis. The isoelectric points of the four components determined by isoelectric focusing were at pH 8.

Biochemical and morphological comparison of two tumour-cell-aggregation factors from rat ascites hepatoma cells.

Two tumour-cell-aggregation factors, derived from rat ascites hepatoma cells, had different antigenicity; one was not absorbed by immunoadsorbent chromatography with anti-rat serum antibody and the other was. Their activities were both lost by digestion with trypsin, but remained unchanged by oxidation with periodate, suggesting the role of the protein portions in their molecules. The potency of the unabsorbed factor was inhibited specifically by alpha-methyl-D-mannoside or D-mannose, while that of the absorbed factor was inhibited specifically by N-acetyl-D-glucosamine, suggesting that these carbohydrates may be concerned with the respective receptor structures at the tumour-cell surface.

Primary action of steroid hormone at the surface of amphibian oocyte in the induction of germinal vesicle breakdown.

An insoluble steroid derivative was prepared by the coupling of desoxycorticosterone with aminoethylated agarose beads. When the naked full-grown Xenopus oocytes were incubated in contact with the steroid-bound agarose beads, the dissociation of oocyte nuclei or the initial step in the maturation of amphibian oocyte was induced in 30-100% of total oocytes. The induction did not occur in the oocytes covered with follicle cells and when the naked oocytes were placed apart from the steroid-bound agarose beads in the medium.

Characterization of tumour cell aggregation promoting factor from rat ascites hepatoma cells: Separation of two factors with different antigenic property.

The previously described glycoprotein that promotes tumour cell aggregation, derived from rat ascites hepatoma cells and capable of partial purification by chromatography, was found to be a mixture of 2 factors with different antigenic property. One was not absorbed by immunoadsorbent chromatography with anti-rat serum antibody and the other was. The action of the unabsorbed factor was clearly more potent than that of the absorbed factor.

A tumour cell aggregation promoting substance from rat ascites hepatoma cells.

A substance capable of promoting tumour cell aggregation was released from rat ascites hepatoma cell (possibly from the cell surface) kept in Hanks' balanced salt solution (free of calcium and magnesium) in the cold, and then partially purified by chromatography with DEAE-Sephadex and gel filtration with Bio-gel. The thermostable substance seemed to be a glycoprotein and its molecular weight was about 72,000 when measured by gel filtration on Sephadex G-200. It had no proteolytic activity.