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Biomedical subjects

T Nikaido

Publications and source records attributed to T Nikaido.

At least 181 records · Page 10Linked to original sources
PubMed1989

Loss in transformed cells of cell cycle regulation of expression of a nuclear protein recognized by SLE patient antisera.

The identification of cellular proteins involved in the control of cell proliferation in normal cells is essential for understanding the mechanism underlying growth regulation and cellular transformation. A nuclear protein termed Ki antigen with a relative mobility of 32,000 (Mr 32K) and which is recognized by SLE patient antisera has been identified in cells of human, bovine, and murine origin. Recently, cDNA clones for the bovine and human Ki antigens have been isolated using SLE patient antisera (T. Nikaido, et al., in preparation). The nucleotide sequence predicted a protein of 239 amino acids with a possible nuclear localization signal resembling that identified in SV40 T antigen and other nuclear proteins. Here we show that the expression of Ki antigen is regulated in the normal cell, but not in the transformed cell. Furthermore, in the K-ras temperature-sensitive mutant cell line, ts 371 normal rat kidney (NRK), Ki antigen expression increases several-fold at the permissive temperature relative to the nonpermissive temperature. These results suggest that expression of Ki antigen might be correlated with cellular transformation as well as with cell growth regulation.

Animals↗
PubMed1989

Inhibition of adenosine 3',5'-cyclic monophosphate phosphodiesterase by flavonoids. III.

Sixty-one flavanones, twenty-six isoflavones and eight other flavonoids, obtained from Sophora tomentosa, S. flavescens, Scutellaria baicalensis and other medicinal plants or synthesized, were tested for their inhibitory activity against adenosine 3',5'-cyclic monophosphate (cAMP) phosphodiesterase from beef heart. The structure-activity relationships were investigated.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1989

[Formulation of photocurable bonding liner and adhesion to dentin. Effect of photoinitiator, monomer and photoirradiation].

An investigation was undertaken to evaluate the effect of both photoinitiators (camphor-quinone-amine systems) and the adhesion promoting monomer (4-MET) on photopolymerization of bonding liners and their adhesion to dentin. Photopolymerization of bonding liners was measured with differential scanning calorimetry (DSC). The bonding liner containing 2-(dimethylamino)ethyl methacrylate (DMAEMA) as a reducing agent decreased the rate of polymerization in the presence of 4-MET. On the other hand, the bonding liners containing N-phenylglycine (NPG) and N,N-dimethylaniline derivatives as a reducing agent showed good polymerization in the presence of 4-MET. The results of the tensile bond test suggested that bonding liners containing NPG and 4-(dimethylamino)benzoic acid (DMABA), one of the N,N-dimethylaniline derivatives, with or without 4-MET bonded well to dentin treated with EDTA 3-2. NPG and DMABA are recommended not only as reducing agents but also as aids in the diffusion of monomers into the dentin substrate. The relationship between the strength of the bond to dentin and photoirradiation of the bonding liner and composite resin was studied. Elongation of photoirradiation of both the bonding liner and composite resin was effective in impacting the strength of the bond to dentin. Furthermore, sufficient photoirradiation of the bonding liner prior to any filling of composite resin was especially important to obtain high bond strengths. SEM and TEM observations supported good adhesion being achieved by hybrid formations between photocurable bonding liners and dentin.

Composite Resins↗
PubMed1989

Renal adenoma. Clinicopathological and histochemical studies.

We report the results of clinicopathological and histochemical studies on 64 renal adenomas found in 22 patients. We selected typical renal adenomas for these studies, discarding borderline lesions. The ages of the patients ranged from 42 to 84 years, with an average of 61 years. Male to female sex ratio was 6.3:1. The background conditions included renal cell carcinoma, long-term dialysis, chronic glomerulonephritis, pyelonephritis, hydronephrosis and polycystic kidney. The sizes of the tumors ranged from 0.1 to 2.3 mm in maximum diameter, with an average of 0.9 mm. All the tumors were located in the cortex, especially in the superficial one-third. The cytoplasm of the tumor cells was predominantly eosinophilic, and the tumor structure was predominantly papillary. Histochemical study of 19 adenomas from 13 patients demonstrated that all of the adenomas from 13 patients demonstrated that all of the adenomas were positive for EMA, and for at least one marker of the distal tubulus, i.e., DBA, PNA, SBA and PKK1, and that 9 adenomas were positive for at least one marker of the proximal tubulus, i.e., LM1 and LTA. Renal adenomas had predominant histochemical features of the distal tubulus, suggesting differentiation to a distal tubulus-like histology.

Adenoma↗
PubMed1987

The human IL-2 receptor gene contains a positive regulatory element that functions in cultured cells and cell-free extracts.

The 130-base pair fragment located between 220 and 90 base pairs upstream of the major transcription initiation site of the human interleukin 2 (IL-2) receptor gene had positive regulatory effect on the early promoter of simian virus 40 as well as its own promoter. This fragment seems to be responsible for not only cell-specific but also lymphokine-induced expression of the IL-2 receptor gene as assessed by DNA transfection. The same DNA fragment directed cell-specific transcription of the IL-2 receptor gene in extract of HTLV-I-infected T cells, MT-1, but not of Epstein-Barr virus-transformed B cells, CESS. The addition of small amounts of MT-1 extract to CESS extract resulted in specific expression of the IL-2 receptor gene, indicating that cell-specific expression is regulated by trans-acting molecules in MT-1 extract.

Animals↗
PubMed1987

Activation of interleukin-2 receptor gene by forskolin and cyclic AMP analogues.

Forskolin (FK), a reversible activator of adenylate cyclase, markedly enhanced the expression of interleukin-2 receptor (IL-2-R) on a human natural killer (NK)-like cell line, YT. The FK-induced increase in IL-2-R on YT cells closely correlated with an increase in intracellular cyclic AMP (cAMP) level, and was mimicked by dibutyryl cyclic AMP (dbcAMP). FK induced both high and low affinity IL-2-R on the cells. Using a cDNA for the IL-2-R as a probe, the FK-induced IL-2-R expression was shown to be associated with an increase in IL-2-R mRNA. FK also enhanced the IL-2-R expression on a human T lymphotrophic virus I (HTLV-I) positive T-cell line (YTA-1H) and augmented the phorbol ester-induced expression of IL-2-R on HTLV-I negative T-cell lines (HSB-2 and HPB-ALL). These results suggest the possibility that the stimulation of adenylate cyclase may serve as a pathway leading to activation of the IL-2-R gene in certain types of lymphocytes.

Adenylyl Cyclases↗
PubMed1987

Transcription of IL-2 receptor gene is stimulated by ATL-derived factor produced by HTLV-I(+) T cell lines.

In HTLV-I transformed T-cell lines established from the patients with adult T-cell leukemia (ATL), there is a constitutive activation of the normal IL-2 receptor (IL-2-R) gene. These cell lines continuously produce an ATL-derived factor (ADF), an IL-2-R inducing factor without IL-2 activity. ADF enhances the expression of the IL-2-R through the augmentation of the IL-2-R mRNA in the HTLV-I(+) T-cell line (ED) as well as the NK cell line cells (YT). In YT cells, the transcriptional initiation of the promoter of the IL-2-R gene was enhanced by ADF but not by IL-2. Production of ADF by HTLV-I(+) T-cell lines may be involved in the abnormal expression of IL-2-Rs on these cells.

Cell Line↗
PubMed1987

Clinicopathological study on small renal cell carcinomas with metastases.

Seven metastasizing small renal cell carcinomas smaller than 30 mm in the greatest diameter were clinicopathologically studied for a better understanding of their characteristic features as compared to those of small tumors without metastases. Grayish-white infiltrating tumors in gross appearance and alveolar or solid microscopic structure consisting of granular or spindle cells and of atypical nuclei were suggestive of having metastases. Two tumors which had positive reactions to the lower nephron markers such as SBA, PNA, and/or DBA were considered to be of lower nephron origin and displayed poor prognosis.

Adult↗
PubMed1986

Expression of interleukin 2 receptors on interleukin 3-dependent cell lines.

Several mouse IL 3-dependent cell lines, IC2, LT4, FDC-P2, and PB-3C, derived from spleen or bone marrow cells were shown to express low affinity receptors for IL 2 (Kd; 0.5 to 8 X 10(-8) M). High affinity receptors for IL 2 were not detected on the IL 3-dependent cells within the experimental limitation of this study. The clones did not respond to IL 2 at all at the concentration as high as 25 micrograms/ml. The number of the receptors expressed on those clones was estimated to be 0.2 to 2 X 10(5)/cell, which is comparable with the number of those on IL 2-dependent T cell clones. Expression of IL 2 receptor was confirmed in mRNA levels for both IC2 and LT4 cells. A relatively low level expression of one (4.5 Kb) of four IL 2 receptor mRNA species was observed with those IL 3-dependent clones compared with IL 2-dependent T cells. It seems that these low affinity receptors may be expressed on IL 3-dependent cells that undergo differentiation or maturation in mast cell and some myeloid cell lineages.

Animals↗
PubMed1985

Molecular cloning and structure of the human interleukin 2 receptor gene.

We have cloned the IL-2 receptor gene from human genomic DNA libraries using IL-2 receptor cDNA as probe. The genomic DNA segments that hybridized with cDNA were subcloned in M13 phages and their sequences were determined. The nucleotide sequences showed that the IL-2 receptor gene was encoded by eight exons and that the coding region sequences agreed completely with that of the IL-2 receptor cDNA cloned from a cell line derived from adult T cell leukemia (ATL), in which IL-2 receptors are expressed abnormally. The nucleotide sequence of the 5'-flanking region had a putative promotor region, which had some homology with the human IL-2 gene. Transcription initiation sites were clustered about 25 bp 3' to the TATA box as assessed by primer extension analysis. These sites for normal and ATL T cells were the same. Exons 2 and 4 encoding the extracytoplasmic portion had significant homology, suggesting that the two exons are derived by duplication of an ancestral exon. Exon 2 contained six cysteine residues, four of which are conserved at the corresponding positions in exon 4.

Amino Acid Sequence↗