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Biomedical subjects

K Kudo

Publications and source records attributed to K Kudo.

At least 19 recordsLinked to original sources
PubMed1979

A possible mechanism for island formation by rat ascites hepatoma cells with special reference to the function of aggregation factor at the cell surface.

Two tumor cell-aggregation factors of glycoprotein nature, separated from rat ascites hepatoma AH136B cells (forming cell islands in vivo), had different antigenicity; one was not absorbed by immunoadsorbent chromatography with anti-rat serum antibody and the other was. The unabsorbed factor induced aggregation (as shown in the form of simple apposition) of rat ascites hepatoma AH109A cells (present as a free form in vivo) and cell adhesiveness characterized by well-defined tripartite junctional complexes, including intermediate junctions, desmosomes, and tight junctions. In contrast, the absorbed factor from AH136B cells, AH109A cells or normal rat serum aggregated AH109A cells but failed to develop the junctional complexes; only simple apposition was observed. AH109A cells themselves contained the absorbed factor but not the unabsorbed factor. AH136B cells proliferating in the skin developed the junctional complexes, while AH109A cells proliferating in the skin did not from any junctional complexes.

Animals↗
PubMed1979

IgE levels in nude mice.

IgE levels in nude mice were estimated by the one-step single radial radiodiffusion method antisera prepared by immunization of guinea pigs with an IgE-rich fraction obtained from sera of normal mice infected with Nippostrongylus brasiliensis and immunized with DNP-ovalbumin in alum gel. 3 out of 8 nude mice had IgE levels significantly higher than those of normal mice.

Animals↗
PubMed1979

Peripheral nerve structures of experimental diabetes rats and the effect of insulin treatment.

The peripheral nerves of alloxan and streptozotocin diabetes rats six months after the induction of diabetes were morphologically investigated. The effect of insulin treatment was also examined. Prominent segmental demyelination and remyelination were observed in both alloxan and streptozotocin diabetes rats by isolated nerve fiber studies. Axonal degeneration and globular swelling were also recognized in some nerve fibers. Transmission electron microscopic findings were characterized by the figures of destructed myelin sheaths and axons. Reduplication and thickening of basal lamina of vasa nervorum were noted in the diabetes rats. Scanning electron microscopy revealed three dimensional architectures of degenerated nerve fibers and rough surface of Schwann cells in the diabetes rats. Insulin treated diabetes rats showed less structural changes of nerve fibers. It was indicated that the peripheral nerve lesions of experimental diabetes rats were caused by metabolic impairment of both axons and Schwann cells. Insulin treatment seemed to be effective on the experimental diabetic neuropathy.

Animals↗
PubMed1979

Regulation of the murine IgE antibody response. I. Characterization of suppressor cells regulating both persistent and transient responses and their sensitivity to low doses of X-irradiation.

Anti-ovalbumin (OA) IgE antibody responses were measured in B6D2F1 mice as a function of time and antigen dose. One hundred to 200 microgram of OA in Al(OH)3 elicited transient responses, whereas 1 to 10 microgram of OA in Al(OH)3 elicited persistent anti-OA IgE responses of high titer. T cells isolated from the spleens of mice mounting either a persistent or a transient response strongly suppressed primary anti-DNP IgE responses in unirradiated recipient mice that were immunized with DNP-OA in Al(OH)3; it was, therefore, concluded that suppressor T cells (Ts cells) were activated during both the persistent and transient IgE responses. Nevertheless, in the present study it was not possible to completely rule out the contention that IgG antibodies may also have been suppressing the IgE response. With a modified adoptive transfer system, it was shown that these Ts cells were sensitive to low doses (250 R) of x-irradiation. The suppressive activity of long-term OA primed cells was also shown to be markedly enhanced when cultured for 24 hr with soluble OA; this finding was interpreted to indicate the presence of memory suppressor cells.

Animals↗
PubMed1979

Studies on nitrate reductase of Clostridium perfringens. II. Purification and some properties of ferredoxin.

A ferredoxin was purified from Clostridium perfringens by DEAE-cellulose chromatography and Sephadex G-50 gel filtration. It had absorption maxima at 390 and 280 nm. The molecular weight was estimated to be 6,000 by Sephadex gel filtration and from the results of amino acid analysis. The isoelectric point was 3.0. It contained four atoms of iron, four atoms of labile sulfur, and six cysteine residues. This ferredoxin as well as ferredoxin from C. pasteurianum acted as an electron donor for nitrate reductase from C. perfringens. The ferredoxin could also act as an electron donor for the hydrogenase from C. pasteurianum in hydrogen evolution.

Amino Acids↗
PubMed1978

IgE antibody response to mite antigen in the mouse. Suppression of an established IgE antibody response by chemically modified antigen.

The antibody response to mite antigen in several mouse strains was studied. BALB/c, CBA, C3H/He, and C57B1 strains showed good responses against mite antigen. The AKR strain, on the other hand, showed a relatively poor response. When BALB/c mice were immunized with DNP-mite conjugate in aluminum hydroxide gel (alum), anti-DNP IgE antibody and IgG1 antibody were induced. When these mice were boosted with mite antigen alone in alum, both anti-mite IgE antibody and IgG1 antibody were induced, although these antibodies were not observed after the first immunization. Both IgE antibody responses were high and persistent. Mite antigen was denatured by alkylation and reduction in the presence of 8 M urea. Native antigen remaining in the chemically denatured antigen was removed by an immunoadsorbent method. The modified mite antigen could stimulate the carrier-specific helper cells, at least when it was injected with alum. It was also found that repeated injections of the modified mite antigen resulted in the suppression of an established IgE antibody response against mite antigen. These findings suggest possible clinical application for hyposensitization therapy.

Animals↗
PubMed1978

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. The unabsorbed factor induced not only cell aggregation (as shown in the form of simple apposition) but also cell adhesiveness characterized by development of intermediate junctions, desmosomes and tight junctions, while the absorbed factor produced only simple apposition, suggesting their functional difference.

Animals↗
PubMed1978

Review of bone grafting for reconstruction of discontinuity defects of the mandible.

Thirty-eight patients with discontinuity defects of the mandible were hospitalized at Iwate Medical University School of Dentistry during the 12-year period from 1965 to 1976. Treatment consisted of grafting autogenous ilium and rib in 35 patients and isologous ilium and Kiel bone in three patients. No bony union was noted in four of 28 cases involving benign tumors, three of eight cases involving malignant tumors, and one of two cases involving old fractures. Postoperative infection was the main cause for lack of union.

Bone Transplantation↗
PubMed1978

Effect of gold salts on the IgE immune response in mice.

In vivo effect of gold salts on the IgE immune response was investigated in mice and rats. It was demonstrated that gold salts did not suppress but rather enhanced the antigen-specific IgE immune response in mice. Moreover, gold salt had on mast cell degranulation in vivo in rats.

Animals↗
PubMed1977

Characterization of the allergenic components of the house dust mite, Dermatophagoides farinae.

Characterization and purification of the allergenic components of the house dust mite, Dermatophagoides farinae, were investigated. It was found that the mite antigen was heat-stable, pronase-sensitive, and periodate-resistant, which suggested that the antigenic determinants of the mite antigen resided mainly in the protein component. Purification of the mite antigen was tried using Sephadex G-150, DEAE cellulose, and isoelectrofocusing columns. The most potent allergenic fraction was around 20,000-30,000 in molecular weight, although the allergenic activity spread in a wide molecular weight range. Prausnitz-Küstner type skin reactions were performed on rats using mouse homocytotropic antibodies for allergenic evaluation, and the clinical usefulness of this method is discussed.

Allergens↗
PubMed1976

The induction of tumour cell adhesiveness and intercellular junctions by a glycoprotein of rat ascites hepatoma cell surface.

Rat ascites hepatoma AH109A cells (present as a free form in vivo) can aggregate and then develop well-defined tripartite junctional complexes, including intermediate junctions, desmosomes and focal tight junctions, on incubation with a glycoprotein separated from rat ascites hepatoma AH136B cells (forming cell islnds in vivo). The development of binding structures was strongly inhibited by actinomycin D. AH109A cells or rat ascites hepatoma YS cells (present as a free form in vivo) previously treated with the glycoprotein for 24 h, when inoculated i.p., proliferated as free cells in the ascitic fluid, like the untreated cells. AH109A cells actively proliferating in the skin do not form any junctional complexes. The reason for the failure of island formation by AH109A cells or YS cells in vivo is discussed.

Animals↗
PubMed1976

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. Both the factors were found in the serum of tumour bearing rats and the action of the unabsorbed factor was also more potent than that of the absorbed factor; its amount increased with time after i.p. inoculation of the cells. The serum of healthy rats contained the absorbed factor but not the unabsorbed factor. It was thus assumed that the unabsorbed factor was associated with the hepatoma cell surface itself and released into the serum, while the absorbed factor was associated with serum protein coating the cell.

Animals↗