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T Nagasawa

Publications and source records attributed to T Nagasawa.

At least 19 recordsLinked to original sources
PubMed1992

Nitrilase from Rhodococcus rhodochrous J1. Sequencing and overexpression of the gene and identification of an essential cysteine residue.

The amino acid sequences of the NH2 terminus and internal peptide fragments of a Rhodococcus rhodochrous J1 nitrilase were determined to prepare synthetic oligonucleotides as primers for the polymerase chain reaction. A 750-base DNA fragment thus amplified was used as the probe to clone a 5.4-kilobase PstI fragment coding for the whole nitrilase. The nitrilase gene modified in the sequence upstream from the presumed ATG start codon was expressed to approximately 50% of the total soluble protein in Escherichia coli. The predicted amino acid sequence of the nitrilase gene showed similarity to that of the bromoxynil nitrilase from Klebsiella ozaenae. The 5,5'-dithiobis(2-nitrobenzoic acid) modification of the nitrilase from R. rhodochrous J1 resulted in inactivation with the loss of one sulfhydryl group/enzyme subunit. Of 4 cysteine residues in the Rhodococcus nitrilase, only Cys-165 is conserved in the Klebsiella nitrilase. Mutant enzymes containing Ala or Ser instead of Cys-165 did not exhibit nitrilase activity. These findings suggest that Cys-165 plays an essential role in the function of the active site.

Amino Acid Sequence↗
PubMed1992

Primary structure of an aliphatic nitrile-degrading enzyme, aliphatic nitrilase, from Rhodococcus rhodochrous K22 and expression of its gene and identification of its active site residue.

Peptides obtained by cleavage of a Rhodococcus rhodochrous K22 nitrilase, which acts on aliphatic nitriles such as acrylonitrile, crotonitrile, and glutaronitrile, have been sequenced. The data allowed the design of oligonucleotide probes which were used to clone a nitrilase encoding gene. Plasmid pNK21, in which 2.05-kb sequence covering the region encoding the nitrilase was was placed under the control of the lac promoter, directed overproduction of enzymatically active nitrilase in response to addition of isopropyl beta-D-thiogalactopyranoside in Escherichia coli. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the cell extract showed that the amount of nitrilase was about 40% of the total soluble proteins, leading to the establishment of a simple purification of the nitrilase. The nucleotide sequence of the nitrilase gene predicts a protein composed of 383 amino acids (M(r) = 42,275), including only one cysteine. The amino acid sequence homology between the Rhodococcus nitrilase and the Klebsiella ozaenae bromoxynil nitrilase [Stalker et al. (1988) J. Biol. Chem. 263, 6310-6314] was 38.3%, and a unique cysteinyl residue (Cys-170) in the former nitrilase was conserved at the corresponding position in the latter nitrilase. Cys-170 of the Rhodococcus nitrilase was replaced by Ala or Ser by site-directed mutagenesis. Both mutations resulted in the complete loss of nitrilase activity, clearly indicating that this cysteinyl residue is essential for the catalytic activity.

Amino Acid Sequence↗
PubMed1992

Affinity chromatographic purification of bovine lung endothelin receptor using biotinylated endothelin and avidin-agarose.

Endothelin receptor was purified from bovine lung by affinity chromatography using biotinylated endothelin and avidin-agarose. Endothelin was biotinylated with sulphosuccinimidyl 2-(biotinamido)ethyl-1,3-dithiopropionate, a reactive form of biotin with a cleavable spacer arm containing a disulphide bond designed for a simple elution by thiols. Starting from 3.5 kg of bovine lung, about 200 micrograms of pure receptor were obtained.

Amino Acid Sequence↗
PubMed1992

Simple, rapid and sensitive determination of plasma taurine by high-performance liquid chromatography using pre-column derivative formation with fluorescamine.

A simple, rapid and sensitive method for the determination of plasma taurine by high-performance liquid chromatography in the isocratic mode has been developed. The deproteinized plasma was treated with fluorescamine. These derivatives were separated on a LiChrospher 100 RP-8 column within 15 min. The detection limit for taurine was 0.2 microM. The plasma taurine contents of yellowtail fish, Seriola quinqueradiata, beef cattle, dairy cows and chickens were determined to be 125 +/- 54, 5.6 +/- 1.4, 2.2 +/- 0.7 and 20.0 +/- 9.6 micrograms/ml, respectively.

Animals↗
PubMed1992

A stromal cell-specific monoclonal antibody augments the stromal cell-dependent B lymphopoiesis.

We produced the mAb R25 against the stromal cell line ST2, which could support B lymphopoiesis in vitro. R25 enhanced the ability of ST2 to support B lymphopoiesis and precipitated molecules of 110 and 120 kDa (p110/120) from ST2 cell lysates. p110/120 were also expressed on other stromal and fibroblast cell lines but not on freshly isolated bone marrow hematopoietic cells, spleen cells, and lymphoid cell lines. However, R25 had no or weak effect on the stromal cell-dependent myelopoiesis. Even under conditions in which bone marrow cells were separated from stromal cells with a membrane filter, R25 could augment the stromal cell-dependent B lymphopoiesis. However, R25 did not induce the increase of IL-7 mRNA of ST2 cells. Taken together, these findings suggest that the stromal cell surface molecules p110/120 are involved in the stromal cell-dependent B lymphopoiesis and that certain soluble factors distinct from IL-7 may contribute to the p110/120-mediated B cell generation.

Animals↗
PubMed1992

Enzymatic synthesis of acrylamide: a success story not yet over.

The application of enzymatic transformations is attracting increasing attention. Until recently, such an approach has generally been confined to producing fine chemicals difficult to obtain through conventional chemical methods. Microbial nitrile hydratase (NHase) has now been applied to the industrial, kiloton-scale production of the important chemical commodity acrylamide. Recent progress in understanding microbial nitrile metabolism at both the gene and protein levels is permitting improvement of the acrylamide production process.

Acrylamide↗
PubMed1992

Effect of casein, casein phosphopeptides and calcium intake on ileal 45Ca disappearance and temporal systolic blood pressure in spontaneously hypertensive rats.

Paracellular 45Ca absorption and temporal systolic blood pressure (SBP) measurements were recorded in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats fed on casein (C) and soya-bean-protein isolate (S) diets, containing 20 (H), 5 (H) and 0.5 (L) g Ca/kg. Similar measurements were also taken in SHR rats only fed on C-M and S-M diets supplemented with 30 g caseinophosphopeptides (CPP)/kg. Absorption of 45Ca from the ileal loop was equivalent in both SHR and WKY animals and largely affected by the level of dietary Ca. In addition, animals fed on C diets exhibited significantly (P < 0.05) greater ileal absorption of 45Ca compared with S-fed animals. This result was attributed to the presence of CPP and a greater (P < 0.05) proportion of soluble 45Ca in the contents of the ileum. Animals fed on S diets supplemented with CPP confirmed this finding. The SBP of SHR rats was higher (P < 0.01) than WKY controls after 9-10 weeks of age. The temporal pattern of observed hypertension was independent of dietary influence in the SHR. The severity of hypertension in SHR rats was affected only by dietary Ca deficiency, and not by Ca supplementation or CPP enhancement of Ca bioavailability. These findings suggest that tryptic digestion products of casein in milk can enhance Ca bioavailability by increasing Ca solubility; however, this action had no effect in reducing hypertension in SHR.

Animals↗
PubMed1992

Resolution and some properties of enzymes involved in enantioselective transformation of 1,3-dichloro-2-propanol to (R)-3-chloro-1,2-propanediol by Corynebacterium sp. strain N-1074.

During the course of the transformation of 1,3-dichloro-2-propanol (DCP) into (R)-3-chloro-1,2-propanediol [(R)-MCP] with the cell extract of Corynebacterium sp. strain N-1074, epichlorohydrin (ECH) was transiently formed. The cell extract was fractionated into two DCP-dechlorinating activities (fractions Ia and Ib) and two ECH-hydrolyzing activities (fractions IIa and IIb) by TSKgel DEAE-5PW column chromatography. Fractions Ia and Ib catalyzed the interconversion of DCP to ECH, and fractions IIa and IIb catalyzed the transformation of ECH into MCP. Fractions Ia and IIa showed only low enantioselectivity for each reaction, whereas fractions Ib and IIb exhibited considerable enantioselectivity, yielding R-rich ECH and MCP, respectively. Enzymes Ia and Ib were isolated from fractions Ia and Ib, respectively. Enzyme Ia had a molecular mass of about 108 kDa and consisted of four subunits identical in molecular mass (about 28 kDa). Enzyme Ib was a protein of 115 kDa, composed of two different polypeptides (about 35 and 32 kDa). The specific activity of enzyme Ib for DCP was about 30-fold higher than that of enzyme Ia. Both enzymes catalyzed the transformation of several halohydrins into the corresponding epoxides with liberation of halides and its reverse reaction. Their substrate specificities and immunological properties differed from each other. Enzyme Ia seemed to be halohydrin hydrogen-halide-lyase which was already purified from Escherichia coli carrying a gene from Corynebacterium sp. strain N-1074.

Bacterial Proteins↗
PubMed1992

A case of autoimmune insulin antibody syndrome associated with polymyositis, empty sella and apparent high urinary output of immunoreactive insulin.

Patients with autoimmune insulin antibody are characterized by hypoglycemic attacks and antibodies to insulin in serum without prior insulin administration. In the present report, a patient with hypoglycemia due to autoimmune insulin antibody associated with primary empty sella syndrome and polymyositis appeared to have high urinary immunoreactive insulin (IRI) in the face of normal urinary C peptide. Consequently, the urinary IRI/C peptide ratio was apparently high. The amelioration of hypoglycemic attacks and polymyositis by prednisolone treatment was accompanied by the disappearance of the antibodies and complete normalization of the urinary IRI and IRI/C peptide ratio. No comparable rise in the urinary IRI and IRI/C peptide ratio was observed in the patients with other disorders studied. Glucose clamp and glucose tolerance study showed decreased sensitivity to exogenous or newly secreted insulin, prolonged half disappearance time of serum insulin, and normal disappearance of blood glucose. These results were consistent with the idea that autoantibodies buffered the effect of exogenous or newly secreted insulin and maintained a relatively constant level of serum free insulin which was not high enough when a large amount of glucose was loaded, but was too high after prolonged fasting, which eventually caused hypoglycemic attacks.

Autoantibodies↗
PubMed1992

A case of Goodpasture's syndrome associated with anti-myeloperoxidase antibodies.

A case of Goodpasture's syndrome with anti-myeloperoxidase (MPO) antibodies is reported. Histological examination revealed crescentic glomerulonephritis and alveolar hemorrhage with linear deposition of IgG along the glomerular capillary walls and alveolar capillary walls by immunofluorescence microscopy. Not only anti-glomerular basement membrane (GBM) antibodies but also anti-MPO antibodies, an anti-neutrophil cytoplasmic antibody, were simultaneously detected in the serum. Although it is generally accepted that crescentic glomerulonephritis in Goodpasture's syndrome is mediated by anti-GBM antibodies, this case suggested that anti-MPO antibodies might also participate in the pathogenesis of crescentic glomerulonephritis and probably alveolar hemorrhage of Goodpasture's syndrome, especially with vasculitis.

Anti-Glomerular Basement Membrane Disease↗
PubMed1992

Multiple myeloma complicated by congestive heart failure following first administration of recombinant alpha-interferon.

A 59-year-old female was admitted to Tsukuba University Hospital and diagnosed as IgA-lambda multiple myeloma (stage IIIA). No cardiovascular disorder with the exception of minor ischemic changes in ECG was revealed before treatment. Recombinant human alpha-interferon (IFN) at a dose of 3 million units combined with melphalan and prednisolone was administrated. Sixteen hours after the first administration of IFN, IFN was suspended by the symptoms of congestive heart failure (CHF). Treatment with diuretics and catecholamine products showed almost complete recovery from CHF in 3 weeks. An adverse reaction to IFN was strongly suspected as the cause of CHF.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

[Presence of thymus-dependent CD4+8+ intestinal intraepithelial lymphocytes and their characteristics in mice].

The purpose of this study was the investigation of the T cell subsets in the gut-associated lymphoid tissues. CD4+8+ T cells were found to appear temporarily in Peyer's patches of mice at 2 to 3 weeks after birth. They disappeared within a short period of time from Peyer's patches, but constantly populated in the intestinal intraepithelial lymphocytes (iIEL). Three to 10% of iIEL were CD4+8+ in the specific pathogen-free (SPF) condition throughout life. They are mature T cells with a high density of CD3 and TcR alpha beta and found to respond to immobilized anti-CD3 antibody. The appearance of CD4+8+ T cells in iIEL was found to be dependent on the thymic selection, since they were absent in the athymic nu/nu mice, and the V beta gene usage was dictated by the pattern of thymic selection. CD4+8+ T cells were not found in the germ-free mice but increased in the SPF old mice. These results indicate that the iIEL contain a unique subset of thymus-derived mature CD4+8+ T cells. These cells may repopulate after the thymic selection in the intestine and increase in response to the intestinal microenvironments.

Aging↗
PubMed1992

[Morphological and immunohistochemical analysis of Ki-1 lymphoma].

We investigated 9 cases of Ki-1 lymphomas morphologically and immunohistochemically. The lymphoma cells infiltrated in the lymph nodes in 7 cases, in the skin in 6 cases, in both in 4 cases and in the bone marrow in 2 cases. In lymph nodes, the giant tumor cells infiltrated paracortical areas, showing a sheet-like appearance or free cell growth pattern and in the marginal and medullary sinuses as well. In the skin, they formed subcutaneous tumor and infiltrated diffusely also in dermis. All cases were positive for Ber-H2, Ki-1 and HLA-DR and 8 cases revealed some of the T cell phenotypes. But Leu-4 and beta F1 for which all 11 peripheral T cell lymphomas were positive, were only positive in 2 cases, respectively. In the present study, the tumor cells were positive for a few antibodies for T lymphocytes and there were few cases showed positivity for Leu-4 and beta F1. The results suggest that it was questionable whether the tumor cells were derived from T lymphocytes. There may be few cases of Ki-1 lymphomas of distinct T cell lineage.

Adolescent↗
PubMed1992

[A case of microscopic polyarteritis nodosa associated with myeloperoxidase-antineutrophil cytoplasmic autoantibodies (MPO-ANCA)].

We report a case of microscopic polyarteritis nodosa associated with myeloperoxidase-antineutrophil cytoplasmic autoantibodies (MPO-ANCA). A 38 year-old female was admitted to our hospital, because of proteinuria, recurrent pyrexia, polyarthralgia, abdominal pain and purpura. She had a history of severe pulmonary hemorrhage and 4 kg weight loss for 8 months. On admission perinuclear ANCA without cytoplasmic ANCA was detected by indirect immunofluorescence assay and MPO-ANCA was detected by enzyme linked immunosorbent assay. But anti-nuclear antibodies, immune complexes and anti-glomerular basement membrane antibodies were not detected. Renal biopsy showed necrotizing crescentic glomerulonephritis without immune deposits. Skin biopsy revealed leukocytoclastic vasculitis. Diagnosis of microscopic polyarteritis nodosa was made by these clinical and histological evidence of vasculitis. As renal failure progressed after admission, corticosteroid and cyclophosphamide administration were started. Renal function and other symptoms improved paralleled with decreased MPO-ANCA titer to normal values. It is suggested that MPO-ANCA may be closely related to the pathogenesis of microscopic polyarteritis nodosa and it may be a good serological marker for diagnosis and disease activity of this disease.

Adult↗
PubMed1992

[Anorexia nervosa with neutropenia--response of neutrophils to G-CSF].

A 50-year-old woman with anorexia nervosa was admitted for evaluation of neutropenia (WBC 1,600/microliters). Her bone marrow was gelatinous, and myeloid cells had decreased. Homogeneous substance deposited in the marrow, stained by alcian blue (pH 2.5), indicative of acid mucopolysaccharides. CFU-G and CFU-GM were decreased in number and myeloid pool in the bone marrow also decreased. Anti-neutrophilic antibody was negative. Neutropenia may be related to myeloid hypoplasia, due to increase of acid mucopolysaccharides replacing adipose cells in the bone marrow under long-term mal-nutritional state. Neutrophils markedly increased by administration of rhG-CSF 5.0 micrograms/kg/day for 14 days without the first peak. Serum G-CSF level did not increase (less than 60 pg/ml). It is effective to administer G-CSF to anorexia nervosa with neutropenia.

Anorexia Nervosa↗