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Biomedical subjects

S Nakai

Publications and source records attributed to S Nakai.

At least 199 records · Page 11Linked to original sources
PubMed1989

Identification of a specific receptor for interleukin-1 on rat bone marrow cells.

The interleukin-1 (IL-1) receptor on rat bone marrow cells was investigated using 125I-labeled IL-1 alpha and -1 beta. These radiolabeled ligands bound to the rat bone marrow cells in a specific and saturable manner with Kd values of 0.36 +/- 0.072 nM and 1.9 +/- 0.27 nM, respectively. In a competitive binding experiment, IL-1 alpha and -1 beta inhibited the binding of 125I-IL-1 alpha with Ki values of 0.35 +/- 0.041 nM and 2.9 +/- 1.0 nM. The binding of 125I-IL-1 beta was inhibited by IL-1 alpha and -1 beta with Ki values of 0.27 +/- 0.020 nM and 0.74 +/- 0.12 nM. In cross-linking experiments, 125I-IL-1 alpha was covalently incorporated into two proteins of 163 kDa and 63 kDa. These results suggested the presence of two binding proteins for IL-1 on the rat bone marrow cells.

Animals↗
PubMed1989

Amino-terminal region of human macrophage colony-stimulating factor (M-CSF) is sufficient for its in vitro biological activity: molecular cloning and expression of carboxyl-terminal deletion mutants of human M-CSF.

Human T lymphoblastoid cell line CEM-ON belongs to a helper/inducer subclass and secretes M-CSF into medium constitutively. We have isolated a full-length cDNA clone for this factor from a cDNA library of this cell line. The cDNA was 2.5 kb and coded for a 554 amino acid polypeptide precursor including signal sequence. The Northern blot analysis showed that the major transcript of M-CSF is about 4.2 kb. We have studied the expression of not only the wild type plasmid, but also the five C-terminal deletion mutants encoding N-terminal 154, 163, 170, 177, and 185 amino acid residues in monkey COS-1 cells. The results showed that at least C-terminal 377 amino acid residues of human M-CSF are not essential to manifest the in vitro biological activity on murine bone marrow cells.

Amino Acid Sequence↗
PubMed1989

Dexamethasone regulation of the expression of cytokine mRNAs induced by interleukin-1 in the astrocytoma cell line U373MG.

BSF-2/IL-6, GM-CSF and IL-1 beta mRNAs were induced by recombinant IL-1 in human astrocytoma cell line U373MG. The induction of BSF-2/IL-6 and IL-1 beta mRNAs did not require de novo protein synthesis while that of GM-CSF mRNA required a newly synthesized protein. Dexamethasone inhibited the induction of these cytokine mRNAs by IL-1. This process seems to require continued protein synthesis. These results suggest that the production of these cytokines are positively and negatively controlled by IL-1 and glucocorticoids, respectively, in astrocytes.

Astrocytoma↗
PubMed1989

The therapeutic potential of interleukin-1 beta in the treatment of chemotherapy- or radiation-induced myelosuppression and in tumor therapy.

In vivo administration of rHuIL-1 beta selectively enhanced the recovery from granulocytopenia and thrombocytopenia caused by sublethal irradiation or 5-FU treatment. Granulopoiesis and thrombopoiesis were stimulated by rHuIL-1 beta in a dose-dependent manner at doses ranging from 0.1 to 100 micrograms/kg. In this study, we have observed IL-1 to induce at least two distinct types of hematopoietic growth factors in vivo, namely GM-CSF and a thrombopoietin-like factor. Various kinds of CSFs alone did not stimulate colony formation of primitive hematopoietic progenitor cells obtained from 5-FU treated mice. However, the pretreatment of primitive hematopoietic progenitor cells with IL-1 in vitro or in vivo for 5 days accelerated the recovery of a cell population which respond to several types of CSFs. These data suggest that IL-1 may be useful clinically to enhance the recovery of granulocytes and platelets in myelosuppressed patients. In addition, we observed that rHuIL-1 beta is directly cytostatic for certain tumor cells in vitro. Intratumoral or subcutaneous injection of rHuIL-1 beta caused regression of a subcutaneous murine sarcoma by augmenting host antitumor responses. Together with the profound effects on hematopoiesis, these results point to potentially important uses of IL-1 beta in treatment of disease.

Animals↗
PubMed1989

Interleukin-1 potentiates granulopoiesis and thrombopoiesis by producing hematopoietic factors in vivo.

In vivo administration of recombinant human interleukin-1 beta (rHu IL-1 beta) selectively enhanced the recovery from granulocytopenia and thrombocytopenia caused by whole body irradiation, in a dose dependent manner. Since IL-1 itself in vitro had no colony-stimulating activity (CSA), we studied whether IL-1 can produce hematopoietic factors in vivo, which in turn will promote granulopoiesis and thrombopoiesis. Serum from IL-1 injected mice showed marked granulocyte/macrophage CSA (GM-CSA), but little megakaryocyte CSA (Meg-CSA). Interestingly, strong megakaryocyte potentiator (Meg-POT) activity was detected in the serum. Further analysis of the serum by gel filtration chromatography showed that Meg-POT activity could be eluted in different fractions from GM-CSA. Since erythropoietin which is known to stimulate erythropoiesis also exhibited remarkable Meg-POT activity, serum from IL-1 injected mice were assayed for erythroid CSA. We found that unlike erythropoietin the serum showed no erythroid CSA. Taken together, these results suggest that IL-1 may potentiate granulopoiesis and thrombopoiesis by producing at least two distinct types of hematopoietic growth factors in vivo, namely granulocyte/macrophage colony-stimulating factor and a thrombopoietin-like factor.

Agranulocytosis↗
PubMed1989

Synthesis of 11 alpha-hydroxyprogesterone haptens.

C-4 and C-6 bridged haptens of 11 alpha-hydroxyprogesterone, an anti-androgen, were respectively synthesized via 4, 5 and 5 alpha, 6 alpha epoxide ring openings using 3-mercaptopropanoic acid. Substitution of 6-bromo derivative of progesterone using the same reagent unexpectedly afforded a C-4 substituted product instead of the normal C-6 substituted product previously reported in the literature.

Chemical Phenomena↗
PubMed1989

Perioperative change of plasma endotoxin levels in early infants.

As a preliminary study to elucidate the relationship of endotoxemia to postoperative morbidity, the plasma endotoxin levels in 64 surgical neonates were quantitated by the chromogenic limulus test (Toxicolor test; Seikagaku Kogyo, Tokyo, Japan). The preoperative levels of plasma endotoxin were 64 +/- 59 pg/mL in the group of infants with perforated peritonitis (n = 9), 63 +/- 51 pg/mL in the group of infants with gastroschisis (n = 7), and 15 +/- 16 pg/mL in the group of infants with ileus (n = 28), while the mean level was 6 +/- 5 pg/mL in the remaining 20 surgical neonates who had no signs of ileus or peritonitis. In the serial determination of plasma endotoxin in 28 neonates, the levels on the first postoperative day increased significantly compared with the preoperative levels (16 +/- 18 pg/mL to 46 +/- 25 pg/mL, P less than .01). They decreased gradually to 8 +/- 5 pg/mL within a week in 15 neonates who had no postoperative complications. However, in 13 neonates who had postoperative complications such as wound infection or postoperative ileus, the postoperative levels of plasma endotoxin increased to a much higher level and remained there. In this article the relationship of clinical endotoxemia to postoperative thrombocytopenia and hyperbilirubinemia is analyzed, and the usefulness of evaluating endotoxemia in surgical neonates is discussed.

Bacterial Infections↗
PubMed1989

Enzymic dephosphorylation of bovine casein to improve acid clotting properties and digestibility for infant formula.

To improve acid clotting properties, enzymic dephosphorylation of caseins with calf intestinal alkaline phosphatase (CAP) or potato acid phosphatase (PAP) was investigated. Greater dephosphorylation was achieved using alpha s1- or beta-casein as substrates, compared to whole casein or skim milk. Electrophoresis of PAP-modified caseins revealed bands with lower mobility and a multibanded pattern in the beta-casein region which was similar to that of human beta-casein. On the other hand, CAP modification produced electrophoretic bands having lower mobility of the beta-casein component, but with higher mobility in the alpha s1-casein component as well as increased net negative charge in the CAP-casein. PAP-casein formed a fine dispersion upon acidification to pH 4, with a microstructure similar to that of acidified human casein. Greater initial rates of hydrolysis by pepsin at pH 4 were observed for both CAP- and PAP-modified caseins, compared to bovine and human caseins. The rate and extent of hydrolysis remained high for CAP-casein but tended to level off with PAP-casein during sequential digestion with pepsin and pancreatin. There may be advantages in the use of partial dephosphorylation to improve acid clotting and digestibility properties of bovine casein for infant feeding.

Acid Phosphatase↗
PubMed1989

Molecular cloning and expression of rat interleukin-1 alpha cDNA.

A cDNA sequence coding for rat interleukin-1 alpha (IL-1 alpha) has been isolated from a cDNA library that was prepared with mRNA derived from LPS-stimulated rat peritoneal macrophages by using human IL-1 alpha cDNA as a probe. The rat cDNA encodes a 270 amino acid residue protein which is homologous (65%) to human IL-1 alpha. The rat cDNA sequence under SV40 early promoter directed the synthesis of biologically active IL-1 in monkey COS-1 cells. Rat IL-1 alpha mRNA is not expressed in spleen, lung, liver or brain, and is also not expressed in these organs of LPS-treated rat except spleen. This suggests that IL-1 alpha is not produced constitutively in various tissues and LPS is not sufficient to induce IL-1 alpha in most tissues. Our data indicate that the IL-1 activities which have been reported to be produced in the brain are not of alpha type. We have constructed a plasmid expressing the carboxy terminal 156 amino acids in Escherichia coli. Recombinant rat IL-1 alpha produced in COS cells or E. coli has cytotoxic activity against the human melanoma cell line A375S1 (GIF activity), which has been reported to be sensitive to human IL-1 alpha and IL-1 beta. This suggests that GIF activity is common to IL-1s derived from various sources.

Amino Acid Sequence↗
PubMed1989

Endocrine cell carcinoma (carcinoid) of the gallbladder.

We report two cases of endocrine cell carcinoma of the gallbladder associated with adenocarcinoma. The patients were women with numerous gallstones. Histologically, the tumors consisted of adenocarcinoma and endocrine cell carcinoma. An apparent transition was noted between the two types. Tumor cells of both the endocrine cell carcinoma and the adenocarcinoma were argyrophilic. In one case the tumor was surrounded by metaplastic mucosa; in the other case, it was surrounded by dysplastic and metaplastic mucosa. The nonneoplastic mucosae also contained argyrophil cells in varying number. These findings suggest that endocrine cell carcinoma of the gallbladder is derived from metaplastic epithelium of the gallbladder.

Adenocarcinoma↗
PubMed1988

The transcription of the interleukin 1 beta gene is induced with PMA and inhibited with dexamethasone in U937 cells.

Interleukin 1 beta mRNA was induced with phorbol ester, not LPS, in the human histiocytic lymphoma cell line U937, but interleukin 1 alpha mRNA was not induced. Nuclear run-on analysis showed that phorbol ester induced the transcription of interleukin 1 beta but did not induce it in the presence of cycloheximide. This indicates that the induction of the transcription with PMA requires de novo protein synthesis. Dexamethasone, an immunosuppressive and anti-inflammatory agent, decreased the level of interleukin 1 beta mRNA induced with phorbol ester. The transcriptional analysis showed that dexamethasone inhibits the transcription of the interleukin 1 beta gene.

Cell Line↗
PubMed1988

A simple, sensitive bioassay for the detection of interleukin-1 using human melanoma A375 cell line.

Interleukin-1 (IL-1) exhibits multiple biological properties on various tissues by modulating immunologic, inflammatory, metabolic, and neurologic functions. Considerable attention has focussed on the measurement of IL-1 activity. We reported a simple, sensitive, and specific bioassay for IL-1 using human melanoma A375 subclone which is highly sensitive for the cell growth inhibitory activity of IL-1. This bioassay method is allows detection of as low as 10pg of IL-1 beta/ml or 30pg of IL-1 alpha/ml. Since this A375 subclone cell dose not respond to prostaglandin E2 plant lectins, lipopolysaccharide, and cytokines such as interleukin-2, interleukin-6, tumor necrosis factor, interferon or colony-stimulating factor, it is an extremely useful and rapid method for the measurement of IL-1 activity in a variety of experimental and clinical conditions. The assay method was used in the presence of antisera to IL-1 beta to discriminate two species of IL-1, IL-1 alpha and IL-1 beta, produced in human peripheral mononuclear cells.

Biological Assay↗
PubMed1988

Macrophage colony-stimulating factor is produced by human T lymphoblastoid cell line, CEM-ON: identification by amino-terminal amino acid sequence analysis.

A subclone, designated CEM-ON, derived from an azaguanine-resistant human leukemic T cell line, CEM-AG(R), constitutively secretes a colony-stimulating factor (CSF) which stimulates the production of macrophages from murine bone marrow progenitor cells. This CSF has been purified from serum-free conditioned medium. Highly purified CEM-ON CSF with a specific activity of 4.7 X 10(7) units/mg protein was obtained. Amino-terminal sequence analysis showed that the first 27 amino acids were identical to the amino-terminal sequence of the M-CSF (CSF-1) based on the cDNAs for human M-CSF. On SDS-PAGE analysis, CEM-ON CSF had an apparent molecular weight of 33,000-43,000; following reduction with 2-mercaptoethanol, this migrated as a 20,000-24,000 subunit, suggesting a homodimer structure. These results show that a human T cell line, CEM-ON, secretes M-CSF into its medium.

Amino Acid Sequence↗
PubMed1988

Site-specific mutagenesis of the human interleukin-1 beta gene: structure-function analysis of the cysteine residues.

Human interleukin-1 beta (IL-1 beta) has two cysteines located at amino acid residues 8 and 71 of the mature protein consisting 153 amino acids. To clarify the role of these characteristic cysteine residues in IL-1 beta, at first, an expression plasmid for site-specific mutagenesis has been constructed by inserting the ori and intergenic region of phage f1 into the IL-1 beta expression vector. The plasmid can be used not only for isolation of the modified IL-1 beta gene but for expression of the mutant protein in Escherichia coli. Using this plasmid, each of the cysteine codons in IL-1 beta gene was changed to serine or alanine codon, or deleted. The modified IL-1 beta showed that the two cysteine residues in IL-1 beta are not essential for biological activity but not to be eliminated for the maintenance of the functional structure of IL-1 beta.

Codon↗