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Biomedical subjects

Y Niitsu

Publications and source records attributed to Y Niitsu.

At least 343 records · Page 19Linked to original sources
PubMed1984

[Induction of tumor necrosis factor (TNF) by OK-432].

The induction of tumor necrosis factor (TNF) by OK-432 was investigated. The results were as follows: Serum from OK-432 injected into NZW rabbits treated with LPS was cytotoxic to tumor cells in vitro. With respect to the target cell spectrum this factor was cytotoxic to L929, Lewis, M7609 and K562, but not to Chang liver cells, HMV cells or HeLa cells. The cytotoxic activity of this factor was found to be M.W. 48,000 on H.P.L.C., and the pI was revealed to be 5.4 by isoelectric focusing. These results were consistent with previously reported findings on TNF.

Animals↗
PubMed1984

Correlations between iron content and isoferritin profiles of normal and malignant tissues.

Isoelectric focusing profiles of ferritins isolated from livers of anemic rats and 3'-methyl-4-dimethylaminoazobenzene-induced hepatomas were more acidic than their normal counterparts, and exhibited patterns similar to those of heart ferritin. Iron administration induced a shift to more basic components for the normal and tumor ferritins. The isoferritin patterns reflected the subunit populations of the protein, as the more acidic components had greater proportions of H-type subunits and iron induced an increase in L subunits with concomitant increases in more basic isoferritins. For both normal and malignant tissues there was a direct correlation between iron content of the tissue and subunit composition. The apparently unique isoferritin patterns in the tumor tissue may, therefore, be ascribed primarily to the lower iron contents.

Anemia↗
PubMed1983

Effects of B2-deficiency on lipoperoxide and its scavenging system in the rat lens.

The level of NADPH-cytochrome c reductase, glutathione reductase and hepatic B2 was significantly decreased in rats fed a B2-deficient diet. The synthesis of ester forms of B2 was decreased more in the lenses of rats fed this diet for 8 weeks than in those fed this diet for 4 weeks. The glutathione reductase activity in the lens decreased as the duration of a B2-deficient diet increased; this may be ascribable to a decrease in the formation in the lenticular riboflavin ester as a coenzyme. The level of lipid peroxides increased in the serum and lenses of rats on the B2-deficient diet, however, compared to the controls, the changes in the activities of superoxide dismutase and glutathione S-transferase were not significant. Lenticular glutathione peroxidase activity was decreased significantly in rats fed the B2-deficient diet for 8 weeks. We suggest that B2 deficiency brings about metabolic disorders in the redox system to maintain lens transparency, that lipoperoxide is accumulated, and that the efficiency of the scavenging system and the activities of glutathione peroxidase and reductase are decreased.

Animals↗
PubMed1983

Studies on the riboflavin-binding capacity of the rat lens.

Previous studies have confirmed that riboflavin-binding protein exists in the rat lens. We now provide evidence that riboflavin-binding was the same at 4 degrees C and 37 degrees C, that there was a saturation curve when 14C-riboflavin was the substrate, that there was an ATP-dependent increase of binding, and that EGTA and PCMB did not affect riboflavin binding while it was decreased upon protease digestion and upon the addition of heavy metal compounds. Furthermore, binding was lower in the lenses of rats which had been fed a B2-deficient diet for 8 weeks than in animals receiving this diet for 4 weeks. When 14C-B2 butyrate rather than 14C-riboflavin was the substrate, binding was considerably higher in the lens homogenate and the single whole lens. Partial purification of riboflavin-binding protein using flavinyl agar-bead affinity chromatography confirmed the presence of a trace amount of riboflavin-binding protein in the bovine lens. Our results suggest that changes in the riboflavin-binding capacity of the lens may play a role in the regulation of absorption, transport and metabolism of riboflavin in the lens associated with the synthesis of ester forms of riboflavin.

Animals↗
PubMed1982

Development of a highly sensitive sandwich enzyme immunoassay for human ferritin using affinity-purified anti-ferritin labelled with beta-D-galactosidase from Escherichia coli.

A highly sensitive sandwich enzyme immunoassay of human ferritin was developed. Polystyrene balls were coated with rabbit anti-human ferritin IgG by physical adsorption, and rabbit anti-human ferritin Fab' was purified by affinity chromatography and labelled with beta-D-galactosidase from Escherichia coli. Using the anti-ferritin-coated polystyrene balls and labelled anti-ferritin, the sensitivity obtained was 23 fg (0.05 amol) of ferritin per tube. The range of serum ferritin levels that could be determined using 0.1 microliter of serum was 0.23-4500 ng/ml, and even 2.3 pg/ml was measurable by using 10 microliter of serum. The coefficients of within-assay (n = 25) and between-assay (n = 10) variations were 5.9-8.8%. The regression equation and coefficient of correlation to a radioimmunoassay were Y(RIA) = 0.92 X(EIA) + 3.0 and 0.99 (n = 78), respectively. The corresponding sandwich radioimmunoassay was less sensitive, partly because the specific radioactivity of 125I-labelled anti-ferritin IgG used was not sufficiently high.

Antibody Specificity↗
PubMed1982

Juvenile polyposis coli. A case report.

We report a case of juvenile polyposis coli in a 13 year old girl who initially complained of rectal bleeding and prolapse of polyps. Tube feeding with an elemental or a low residue diet and total parenteral nutrition were prescribed to treat the hypoproteinemia and anemia. A modified Soave's operation was successfully performed. The polyps appeared in several different stages of development. A single dilated gland of the colonic mucosa, which was not grossly visible, was presumed to be the site of the initial lesion which developed into a typical juvenile polyp. Adenomatous tubules were found in some juvenile polyps. In this case of immunologic deficiency, it is not clear whether such was a primary or secondary phenomenon.

Adolescent↗
PubMed1982

Mild and efficient conjugation of rabbit Fab' and horseradish peroxidase using a maleimide compound and its use for enzyme immunoassay.

A mild and efficient procedure for conjugating rabbit Fab' and horseradish peroxidase using a maleimide compound was developed. The enzyme was treated with N-hydroxysuccinimide ester of N-(4-carboxycyclohexylmethyl) maleimide to introduce maleimide groups. Then, the maleimide-enzyme was allowed to react with thiol groups of Fab', and the conjugate formed was separated from unreacted components by gel filtration with Ultrogel AcA 44. In the peak fraction of the separated conjugate, 98% of peroxidase was associated with Fab' and 90% of antibodies was associated with peroxidase. The recoveries in the conjugate of peroxidase and Fab' incubated for conjugation were 65-74%. The conjugate formed appeared to be largely monomeric. Both the enzyme activity and antigen-binding activity of Fab' were fairly well preserved in the conjugate. The cross-link formed was stable at 4 degrees C at least 6 months. Use of the conjugates obtained by this method gave greater sensitivity in sandwich enzyme immunoassay for human ferritin and human thyroid-stimulating hormone than conjugates prepared by the periodate method. The conjugation using N-hydroxysuccinimide ester of m-maleimidobenzoic acid provided a similar monomeric preparation but was less efficient.

Animals↗
PubMed1982

Major factors limiting sensitivity of sandwich enzyme immunoassay for ferritin, immunoglobulin E, and thyroid-stimulating hormone.

By using IgG-coated polystyrene balls and beta-D-galactosidase-labelled Fab', sandwich enzyme immunoassays for human ferritin, immunoglobulin E (IgE), and thyroid-stimulating hormone (TSH) were developed, and their sensitivities were shown to be largely limited by the purity, binding efficiency, and amount of beta-D-galactosidase-labelled Fab' used. (1) Their sensitivities were enhanced 10 to 50-fold by using affinity-purified Fab' labelled with beta-D-galactosidase. (2) Their sensitivities depended upon the efficiency of specific binding of the labelled Fab' to antigens adsorbed on antibody IgG-coated polystyrene balls. (3) Their sensitivities were improved by using the minimal amount of labelled Fab' that gave a reliable calibration curve. Under optimal conditions the sensitivities obtained for ferritin, IgE, and TSH were 0.09 pg (0.2 amol), 0.48 pg (2.4 amol, 0.2 mIU), and 3.2 millimicronU (5.7 amol) per tube, respectively.

Ferritins↗
PubMed1982

[Case of choriocarcinoma of a probable testicular origin with a good response to cis-diamminedichloroplatinum (CDDP)].

A case of choriocarcinoma responding well to cis-diamminedichloroplatinum (CDDP) was reported. A 24-year-old male was admitted to our hospital with chief complaints of upper abdominal discomfort and gynecomastia. Physical findings on admission included solid tumors in the upper abdomen and bilateral inguinal regions. The chest X-ray picture showed numerous coin lesions, and abdominal ultrasound examination revealed a widespread metastasis in the retroperitoneum. Blood chemical analysis pointed out the high levels of LH, HCG, and beta-subunit of HCG. The pathological diagnosis of the biopsied inguinal mass was choriocarcinoma. The patient was treated with CDDP, vincristine and bleomycin according to the protocol of Einhorn. After three courses of this therapy, serum HCG level was normalized and pulmonary metastatic lesions were diminished, although abdominal ultrasound examination showed remnants of the decreased tumor masses. The patient was transferred to the urological department for further cytoreductive therapy.

Adult↗
PubMed1980

Assembly of intra- and interspecies hybrid apoferritins.

An intraspecies hybrid apoferritin was assembled by mixing subunits of horse heart ferritin, which consists mainly of H-type subunits, and horse spleen ferritin, in which L-type subunits predominate. Interspecies hybrid apoferritins were reconstituted from subunits of human liver-horse spleen ferritins and from rat liver-horse spleen ferritins. All the hybrid ferritins migrated as single zones with electrophoretic mobilities intermediate between those of the parent ferritins. Isoelectric focusing data and immunological patterns were consistent with the view that the reassembled apoferritins were composite molecules that contained subunits from each of the interacting forms. Reconstitution occurred in a random manner, as there was no apparent preference for assembly of homologous subunits. These results suggest that intersubunit interaction domains and recognition mechanisms that dictate formation of the highly specific quaternary structure assumed by this protein are common for different species of ferritins.

Animals↗