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Biomedical subjects

S Shimizu

Publications and source records attributed to S Shimizu.

At least 757 records · Page 42Linked to original sources
PubMed1989

Establishment of two interleukin 6 (B cell stimulatory factor 2/interferon beta 2)-dependent human bone marrow-derived myeloma cell lines.

Two IL-6-dependent human multiple myeloma cell lines, ILKM2 and ILKM3, were established from the bone marrow of patients with IgG-K multiple myeloma. Both cell lines had the typical morphology and immunocytochemical features of myeloma cells. The surface phenotype of both cell lines was PCA-1+, OKT10+, CD10(J-5)-, CD19(B4)-, CD20(B1)-, CD21(B2)-, and OKIa-1-. A monoclonal cytoplasmic Ig, IgG-K or K L chain, was positive in ILKM2 or ILKM3, respectively. EBV nuclear antigen was negative in both cell lines. They proliferated in the presence of macrophages or macrophage-derived factors (MDF). Among the recombinant cytokines examined, IL-6 most strongly augmented the growth of both cell lines. The anti-IL-6 antibody completely inhibited the IL-6-dependent growth and almost completely inhibited the MDF- or purified MDF-dependent growth of both cell lines, ILKM2 and ILKM3 are now being maintained in the culture medium containing 2 ng/ml rIL-6. These results suggest that IL-6 produced by macrophages may play an important role in the growth of myeloma cells in vivo and that macrophages or IL-6 can be used for establishing human myeloma cell lines.

Antigen-Antibody Reactions↗
PubMed1989

A nitrous acid procedure as a selective histochemical means of eliminating the N-sulphates of glycoconjugates.

A nitrous acid procedure has been shown to lead to the elimination of N-sulphates in sections of a series of tissues containing sulphated glycoconjugates. Two groups of sulphated glycoconjugate-containing tissues were used; one contained N-sulphates and other was devoid of such groupings. In the first group of tissues, mast cells of different origins and renal glomeruli in the rat were employed. Xiphoid and tracheal cartilage matrix, submandibular and sublingual gland acini and gastric, duodenal and colonic mucosae were used in the second group. Sections were treated with nitrous acid and then stained with Alcian Blue pH 1.0, high iron diamine or Aldehyde Fuchsin for sulphated glycoconjugates. Such treatment was found to diminish the staining intensities exclusively in N-sulphated glycoconjugate-containing structures such as mast cell granules and renal glomerular basement membrane, providing a means of chemically eliminating N-sulphates of glycoconjugates in tissues.

Acetates↗
PubMed1989

A high incidence of rheumatoid factor idiotypes in monoclonal proteins in the serum and in lymphoma cells in patients with Sjögren's syndrome.

Patients with Sjögren's syndrome (SS) develop lymphoproliferative disorders such as monoclonal gammopathies and non-Hodgkin's lymphomas. Cross-reactive idiotypes (CRI) were studied in 22 serum monoclonal immunoglobulins (Igs) and in cytoplasmic Ig in four B-cell lymphoma cells in patients with SS. This was done by utilizing monoclonal anti-idiotypic antibodies which were produced against monoclonal rheumatoid factors (RF) derived from three patients with SS and one patient with Waldenström's macroglobulinemia. By the Western blotting or dot immunobinding technique, CRI was detected not only in monoclonal RFs but in monoclonal Igs which had different heavy- or light-chains from the original monoclonal RF used for immunization. A higher incidence of CRI was found in 22 monoclonal Igs associated with SS than in 27 monoclonal Igs in patients with Waldenström's macroglobulinemia, multiple myeloma or malignant lymphoma. In four patients with malignant lymphoma associated with SS, three showed one or three CRI in the lymphoma cells, whereas only two out of 20 patients with other malignant lymphoma showed CRI, demonstrating a significant difference between two groups. These data indicate that monoclonal proliferation of B-cell lineage in patients with SS, benign or malignant, takes place more often among RF-producing clones than other B-cell disorders.

Antibodies, Monoclonal↗
PubMed1989

Ketopantoyl lactone reductase is a conjugated polyketone reductase.

Ketopantoyl lactone reductase (EC 1.1.1.168) of Saccharomyces cerevisiae was found to catalyze the reduction of a variety of natural and unnatural conjugated polyketone compounds and quinones, such as isatin, ninhydrin, camphorquinone and beta-naphthoquinone in the presence of NADPH. 5-Bromoisatin is the best substrate for the enzyme (Km = 3.1 mM; Vmax = 650 mumol/min/mg). The enzyme is inhibited by quercetin, and several polyketones. These results suggest that ketopantoyl lactone reductase is a carbonyl reductase which specifically catalyzes the reduction of conjugated polyketones.

Alcohol Oxidoreductases↗
PubMed1989

Inhibition of Na+,K+-ATPase activity by phospholipase A2 and several lysophospholipids: possible role of phospholipase A2 in noradrenaline release from cerebral cortical synaptosomes.

p-Bromophenacyl bromide (PBPB), quinacrine and indomethacin, which inhibit phospholipase A2 (PLA2; EC 3.1.1.4) activity in several tissues, caused a dose-dependent inhibition of prelabelled [3H]noradrenaline ([3H]NA) release evoked by high concentrations of K+ from rat cerebral cortical synaptosomes. Release of prelabelled [3H]NA was caused by natural lysophosphatidic acid (LPA; 10(-6)-10(-5) g mL-1) and lysophosphatidylcholine (LPC; 10(-6)-10(-5) g mL-1) and synthetic LPA (6 x 10(-6), 2 x 10(-5) M) and LPC (6 x 10(-6), 2 x 10(-5) M), but not by natural lysophosphatidylserine (LPS; 10(-5) g mL-1), lysophosphatidylethanolamine (LPE; 10(-5) g mL-1) and lysophosphatidylinositol (LPI; 10(-5) g mL-1). The release evoked by natural LPA and LPC could be inhibited only marginally by PBPB and quinacrine. Phosphatidic acid (PA)-specific and phosphatidylcholine (PC)-specific PLA2 activities from rat cerebral cortical synaptosomes were stimulated in incubation medium containing high concentrations of K+ or calcium ionophore A23187. Low concentrations of PLA2 (10(-6)-10(-8) g mL-1, from bee venom) inhibited the synaptic membrane Na+,K+-ATPase activity in incubation media with intracellular levels of free Ca2+. Several lysophospholipids (LPLs), metabolites of the PLA2 type, also inhibited the synaptic membrane Na+,K+-ATPase activity in a dose-dependent manner. The minimum effective concentrations of natural LPA, LPC, LPS, LPI and LPE were 10(-6), 4.7 x 10(-6), 10(-5), 4.7 x 10(-5) and 4.7 x 10(-5) g mL-1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Cloning of an endo-1,4-beta-D-glucanase gene from Clostridium josui and its expression in Escherichia coli.

The gene for carboxymethyl cellulose-degrading enzyme (endoglucanase) from Clostridium josui (FERM P-9684) was cloned in Escherichia coli HB101 with pBR322. A 5.6-kilobase-pair HindIII fragment encoding an endoglucanase was hybridized with C. josui chromosomal DNA. The size of the cloned DNA fragment was reduced with PvuII, and the resulting active fragment (2 kilobase pairs, with restriction sites of EcoRI and PstI) was ligated into pUC118 at the SmaI sites (pUCJ1). The endoglucanase production by E. coli JM103(pUCJ1) in Luria-Bertani broth was enhanced up to approximately three times by maintaining the pH at 6.5 and using 80 mM NaCl.

Bacterial Proteins↗
PubMed1989

In vitro reconstitution of a hexagonal array with a surface layer protein synthesized by Bacillus subtilis harboring the surface layer protein gene from Bacillus brevis 47.

Bacillus brevis 47 contains two surface layer proteins, termed the outer wall protein and the middle wall protein (MWP), which form a hexagonal array in the cell wall. Introduction of the MWP structural gene into Bacillus subtilis by using a low-copy-number plasmid led to the synthesis of an immunoreactive polypeptide with a molecular mass almost the same as that of the MWP synthesized by B. brevis 47. Biochemical analysis indicated that most of the MWP synthesized by B. subtilis was localized in the cytoplasmic fraction. This was further confirmed by using immunogold electron microscopy. The amino-terminal amino acid sequence of the MWP purified from the cytoplasm of B. subtilis indicated that the MWP was precursor with a signal peptide of 23 amino acid residues to the amino terminus of the mature protein. The precursor of the MWP possessed the ability to reassemble in vitro on the B. brevis 47 peptidoglycan layer, resulting in the formation of almost the same hexagonal arrays as with the mature MWP purified from B. brevis 47, judging from images averaged at a resolution of about 2.5 nm. Furthermore, a center-to-center distance of the hexagonal lattice on the envelope reconstituted by using the precursor MWP was calibrated as 18.3 nm, which was almost identical to the value of 17.8 nm obtained with the mature protein.

Amino Acid Sequence↗
PubMed1989

Structure of a Ruminococcus albus endo-1,4-beta-glucanase gene.

A chromosomal DNA fragment encoding an endo-1,4-beta-glucanase I (Eg I) gene from Ruminococcus albus cloned and expressed in Escherichia coli with pUC18 was fully sequenced by the dideoxy-chain termination method. The sequence contained a consensus promoter sequence and a structural amino acid sequence. The initial 43 amino acids of the protein were deduced to be a signal sequence, since they are missing in the mature protein (Eg I). High homology was found when the amino acid sequence of the Eg I was compared with that of endoglucanase E from Clostridium thermocellum. Codon usage of the gene was not biased. These results suggested that the properties of the Eg I gene from R. albus was specified from the known beta-glucanase genes of the other organisms.

Amino Acid Sequence↗
PubMed1989

Purification and properties of an endo-1,4-beta-glucanase from Clostridium josui.

An enzyme active against carboxymethyl cellulose (CMC) was purified from the stationary-phase-culture supernatant of Clostridium josui grown in a medium containing ball-milled cellulose. The purification in the presence of 6 M urea yielded homogeneous enzyme after an approximately 50-fold increase in specific activity and a 13% yield. The enzyme had a molecular mass of 45 kilodaltons. The optimal temperature and pH of the enzyme against CMC were 60 degrees C and 6.8, respectively. The enzyme hydrolyzed cellotetraose, cellopentaose, and cellohexaose to cellobiose and cellotriose but did not hydrolyze cellobiose or cellotriose. A microcrystalline cellulose, Avicel, was also hydrolyzed significantly, but the extent of hydrolysis was remarkably less than that of CMC. On the basis of these results, the enzyme purified here is one of the endo-1,4-beta-glucanases. The N-terminal amino acid sequence of the enzyme is Tyr-Asp-Ala-Ser-Leu-Lys-Pro-Asn-Leu-Gln-Ile-Pro-Gln-Lys-Asn-Ile-Pro-Asn- Asn-Asp-Ala-Val-Asn-Ile-Lys.

Amino Acid Sequence↗
PubMed1989

Isolation of an acidic protein from cholesterol gallstones, which inhibits the precipitation of calcium carbonate in vitro.

In seeking to identify nucleating/antinucleating proteins involved in the pathogenesis of cholesterol gallstones, a major acidic protein was isolated from each of 13 samples of cholesterol gallstones. After the stones were extracted with methyl t-butyl ether to remove cholesterol, and methanol to remove bile salts and other lipids, they were demineralized with EDTA. The extracts were desalted with Sephadex-G25, and the proteins separated by PAGE. A protein was isolated, of molecular weight below 10 kD, which included firmly-bound diazo-positive yellow pigments and contained 24% acidic, but only 7% basic amino acid residues. The presence of N-acetyl glucosamine suggested that this was a glycoprotein. This protein at concentrations as low as 2 micrograms/ml, but neither human serum albumin nor its complex with bilirubin, inhibited calcium carbonate precipitation from a supersaturated solution in vitro. This protein could be precipitated from 0.15 M NaCl solution by the addition of 0.5 M calcium chloride. Considering that cholesterol gallstones contain calcium and pigment at their centers, and that small acidic proteins are important regulators in other biomineralization systems, this protein seems likely to play a role in the pathogenesis of cholesterol gallstones.

Amino Acids↗
PubMed1989

Different modes of inhibition of rat gastric mucosal 6-keto-PGF1 alpha production by indomethacin, aspirin and aminopyrine.

The actions of aminopyrine on rat gastric mucosal cyclooxygenase activity in vitro were investigated and compared with those of the cyclooxygenase inhibitors indomethacin and aspirin. Aminopyrine is a phenyl-pyrazolone derivative with potent analgesic and antipyretic properties, but is weakly ulcerogenic, while indomethacin and aspirin are known to cause considerable ulcerogenesis. Aminopyrine was less potent in its ability to inhibit cyclooxygenase activity. The inhibition by all three drugs decreased with an increase in the substrate concentration. Pre-incubation with the enzymes greatly increased the inhibitory action of indomethacin and aspirin, but only slightly increased that of aminopyrine. The inhibitory action of aminopyrine was reversible, whereas those of indomethacin and aspirin were irreversible. These findings are discussed in relation to the low incidence of gastrointestinal irritation caused by aminopyrine.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

Temporal changes of plasma erythropoietin level in hypobaric hypoxic mice and the influence of an altered blood oxygen affinity.

Temporal changes of plasma erythropoietin (Epo) in mice exposed to hypobaric hypoxia were studied by a fetal mouse liver cell culture method. Since a colony formation inhibitory activity was found in the mouse plasma, thirteen pretreatment procedures for bioassay were compared and the procedure of shaking with chloroform followed by dialysis was concluded to be the best. When normal mice (P50 = 40.4 +/- 2.2 Torr) were exposed to hypoxia of 350 Torr, the plasma Epo level was elevated, with peak at the 2nd to 3rd day, and afterwards declined gradually. On the contrary, cyanated mice (P50 = 30.1 +/- 1.5 Torr) showed much less of the Epo response when exposed to 350 Torr. Under 200 Torr hypoxia, both mice exhibited a similar and remarkable extent of the response. These results suggest that the renal Epo-producing tissue or its oxygen-sensing system is less hypoxic in cyanated mice than in normal mice under 350 Torr, and that the physiologically optimal oxygen affinity of blood is variable depending on hypoxic degrees. The fact that the inhibitory activity showed an inverse temporal change to that of Epo, suggested a possible important role of this activity in the regulation of erythropoiesis under hypoxia.

Administration, Oral↗
PubMed1989

Hb Hope, beta 136(H14)Gly----Asp, in a diabetic Japanese female and its functional characterization.

A beta-variant hemoglobin, first misjudged as a marked elevation of Hb A1, was found in a 68-year-old Japanese female with diabetes mellitus. This hemoglobin was isolated by Bio-Rex 70 chromatography combined with chromatofocusing, and was found to be Hb Hope, beta 136(H14)Gly----Asp, by classical and high performance liquid chromatographic peptide mapping techniques. Intrinsic oxygen affinity of this hemoglobin was approximately one-third as compared with that of Hb A0. This property was still observed in the constituent beta subunits isolated. Effects of such allosteric effectors as H+ (at a fixed concentration of Cl-), anion (Cl-), 2,3-diphosphoglycerate and carbon dioxide were more or less depressed. Among others, a marked reduction in the carbamate effect should be noted in a structural interpretation of the functional modifications. Subunit cooperativity, on the contrary, was not different from that in Hb A0 (n = 2.8-2.9). Explanation of these altered functions were attempted on the basis of the altered structure. The reduced stability of Hb Hope is also described.

Aged↗
PubMed1989

Development of precipitating antibody in chickens experimentally infested with northern fowl mite, Ornithonyssus sylviarum (Acari: Macronyssidae).

In order to examine the immune response of chickens to different population levels of mites, a microscopic slide modification of the Ouchterlony double-gel diffusion technique was adopted for examination of circulating antibody against the extract of northern fowl mite, Ornithonyssus sylviarum. Precipitating antibodies were detected in all the chickens infested with the mite. One to three clearly defined precipitation lines appeared in almost all the serum samples of infested birds. Titers of antibody correlated with population levels of the mite on chickens, and no differences in antibody development of hens and roosters were distinguished. These results suggest that the titration of precipitating antibodies appears to be useful for the assessment of mite population levels on chickens.

Animals↗
PubMed1989

[Estrogen production in epithelial tumors of the ovary--identification of estrogen-synthesizing cells].

Morphological, fine structural and enzyme histochemical investigation of common epithelial tumors of the ovary was aimed at identifying the estrogen-synthesizing cells in the stroma of the tumor. Histological changes in cell condensation or "thecosis" and cell enlargement or "luteinization" were commonly observed in the stromal area of the tumor. Two types of stromal cells were found by electron microscopic study; one had characteristic organelles of steroid hormone-producing cells, and the other had a similar cytoplasmic structure to that of fibroblastic cells. Both types of cells had lipid droplets in the cytoplasm. The former seemed to be transformed from the latter. Steroidogenesis-related enzymes such as 3 beta-hydroxy steroid dehydrogenase (HSD) and 17 beta-HSD were demonstrated in the stromal cells. Electron microscopy revealed that these enzymes were localized at the intercrystal space and inner membrane of mitochondria with tubular crystal. These findings indicated that thecosis appeared in the stroma of the epithelial tumor, and the stromal cell acquired estrogen-producing potential.

Cytoplasm↗