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M Sakaguchi

Publications and source records attributed to M Sakaguchi.

At least 415 records · Page 23Linked to original sources
PubMed1988

Molecular cloning and nucleotide sequence of tuna growth hormone cDNA.

cDNA for mRNA of tuna growth hormone (GH) was cloned by screening a cDNA library constructed from tuna pituitary gland poly(A)+ RNA. The nucleotide sequence of cDNA (911 bases) revealed an open reading frame of 615 nucleotides, including a sequence (51 bases) for a possible secretory protein leader peptide. Noncoding regions were found in the nucleotide sequences up- (5'-terminal: 65 bases) and down- (3'-terminal: 231 bases) stream of the open reading frame. An amino-acid sequence deduced from the nucleotide sequence of the cDNA was identical with that determined in the purified tuna GH. Tuna GH was composed of 187 amino acids, and had a calculated molecular weight of 21,275. Amino-acid sequencing showed that there was one possible N-glycosylation site at Asn (Asn-Cys-Thr). Tuna GH showed amino-acid sequence homologies with chum salmon (67%), yellow tail (90%) and with human (32%) growth hormones.

Amino Acid Sequence↗
PubMed1988

Alteration of cell cycle progression in human leukemia cell line (KOPM-28) induced by 12-o-tetradecanoylphorbol-13-acetate.

Terminal cell differentiation usually results in an irreversible arrest in the G1 phase of the cell cycle and loss of cell renewal ability. Human promyelocytic leukemia HL-60 cells induced with 12-o-tetradecanoylphorbol-13-acetate (TPA) differentiate into monocytes/macrophages and accumulate in G1. We determined the effect of TPA on the growth kinetics of a human leukemia cell line (KOPM-28), which developed several of the characteristics of megakaryocytes in response to TPA, such as the surface antigen complex IIb/IIIa, platelet peroxidase and polyploidy. Cell growth was immediately and completely inhibited by TPA. Flow cytometric analysis of cellular DNA content revealed a gradual decrease in cells in G1 and an accumulation of cells in G2. These data suggest that TPA prolonged G1 and rapidly arrested the cells in G2. Synchronized cells were utilized to further analyze the rapid G2 arrest. Cells arrested with aphidicolin at the G1/S interphase were released, and the effects of TPA (added at different intervals) on cell cycle progression were examined 14 h after release. The results showed that TPA added at the end of the S phase, as well as at the G1/S interphase incompletely but distinctly arrested cells in G2. Moreover, G2 arrest was observed when TPA was added to cells released from a colcemid-induced G2/M block, suggesting that cells already in G2 were inhibited by TPA from moving through M to G1. Since some cells became multi-nucleated in the course of incubation with TPA, this G2 accumulation may have resulted at least in part from a prolongation of the phase or a transient G2 block. These changes in cell cycle progression induced by TPA may be characteristic of and/or related to megakaryocytic differentiation of hemopoietic precursor cells.

Cell Cycle↗
PubMed1988

Carcinoma of the colon in children: report of a case and review of the literature.

Carcinoma of the colon seen in an 11-year-old boy is reported herein. The patient had advanced carcinoma of the ascending colon and died 8 months after an ileo-transversostomy had been performed as a palliative procedure. Histologically, the tumor was found to be signet-ring cell carcinoma. 29 cases of colon carcinoma reported in Japanese children under 15 years of age are also reviewed. In 19 of these patients, surgery was done as an elective procedure after the diagnosis of colon cancer had been established, but emergency surgery was performed on 10 patients for perforation or obstruction of the bowel. Curative resection was possible in 14 patients, but of these, only 3 patients survived for more than 10 years.

Adenocarcinoma, Mucinous↗
PubMed1988

A reverse-sandwich ELISA for IgG antibody to a pollen allergen.

We have developed a reverse-type sandwich ELISA for measurement of IgG (+IgA) antibody to a major allergen of Sugi (Japanese cedar) pollens. In this assay, microplate wells were coated with the allergen proteins that had been dispersed in the presence of 0.5 mol/L NaCl and 20 micrograms/ml of bovine serum albumin, followed by addition of test serum, and then the biotinylated allergen. Beta-galactosidase-conjugated streptavidin was used for detection of the captured allergen, 4-methylumbelliferyl-beta-D-galactoside was used as the enzyme substrate, and fluorescence intensity of the product, 4-methylumbelliferone, was measured by a fluorometric reader. This assay was found to detect a total activity of IgG, IgA, and IgE antibodies present in the serum of the patients with pollinosis. IgG (+IgA) antibody was determined after absorption of the serum with anti-IgE Sepharose gel. Sera from individuals who were unexposed to the pollens demonstrated no nonspecific reactions in this assay. This method may be useful as a simple technique for monitoring the efficacy of immunotherapy that is expected to elicit IgG blocking antibody and also for large-scale seroepidemiologic studies on the prevalence of non-IgE antibodies in a general population.

Allergens↗
PubMed1988

Effects of dietary taurine on tissue taurine and free amino acid levels of the chum salmon, Oncorhynchus keta, reared in freshwater and seawater environments.

1. Young chum salmon were fed on the basal and taurine-supplemented diets for 30 days in freshwater (FW) and for 25 days in seawater (SW). Levels of taurine, major free amino acids (FAA) and non-protein nitrogen (NPN) in various tissues were determined. 2. Tissue taurine levels were higher when fish were fed on the taurine-supplemented diets. All tissues of the SW fish did not contain higher taurine levels than those of the FW. 3. Levels of major FAA in the tissues differed little between fish fed on the basal and taurine-supplemented diets and also between the FW and SW fish. 4. No difference was observed in tissue NPN levels between fish ingesting the basal and taurine-supplemented diets; the levels were slightly higher in the SW fish.

Acclimatization↗
PubMed1988

Both amino- and carboxy-terminal portions are required for insertion of yeast porin into the outer mitochondrial membrane.

Yeast porin, the major outer mitochondrial membrane protein, is synthesized without a cleavable extension peptide and post-translationally inserted into the membrane. When inserted into the membrane, it acquires resistance to externally added trypsin. To locate the sequences responsible for membrane insertion and topogenesis in the primary structure of yeast porin, we constructed several deletion and chimeric mutants of the porin cDNA. These cDNAs were expressed in vitro and the products were assayed for capacity to be correctly inserted into isolated mitochondria. It was thus found that deletion of the segment spanning residues 37-98 did not appreciably impair the insertion competence and the inserted protein became resistant to trypsin. On the other hand, the porin mutant lacking the segment consisting of residues 17-98 did not acquire the trypsin resistance, though it could bind to mitochondria specifically. Deletion of the carboxy-terminal 62 amino acid residues also abolished the capacity to be correctly inserted into mitochondria. We conclude that information required for membrane insertion and intramembranous topogenesis of the porin molecule is stored not only in the amino-terminal region but also in the carboxy-terminal portion.

Alkalies↗
PubMed1988

Site-specific mutagenesis of the human interleukin-1 beta gene: the role of arginine residue at the N-terminal region.

Using the expression system for site-specific mutagenesis in Escherichia coli, we have made deletion mutants at the N-terminal or C-terminal region of human interleukin-1 beta (IL-1 beta) consisting of 153 amino acids. The truncated mutants showed that at least 147 amino acids (numbers 4-150) in IL-1 beta are necessary for the exertion of biological activity. When we changed the arginine at the 4th position (Arg4) in IL-1 beta to other specific amino acids, there was a marked difference in the relative extent of biological and receptor binding activities among the mutants. The order of the mutants was Arg4 = Lys4 greater than Gln4 greater than Gly4 = des-Arg4 greater than Asp4. Our results demonstrate that the arginine residue at the 4th position in IL-1 beta is important, but not essential, for IL-1 beta to exhibit its biological and receptor binding activities, and the positive charge at this site plays a key role for IL-1 beta to exert the activities.

Arginine↗
PubMed1988

Growth-promoting activity of tuna growth hormone and expression of tuna growth hormone cDNA in Escherichia coli.

Tuna (Thunnus thynnus) growth hormone (GH) was purified by using a column of Sepharose 4B to which tuna GH-specific IgG was linked. The molecular weight and isoelectric point of tuna GH were 21,000 and 6.5, respectively. The growth of snapper (Pagrus major) was remarkably accelerated when the purified hormone was administered by four intraperitonial injections at intervals of 5 days: 1.5-fold in length and 1.9-fold in body weight/60 days. To produce tuna GH in Escherichia coli cells, expression plasmids pTES8 and pTES8S for tuna GH cDNA with or without the signal peptide region were constructed and GH production in E. coli cells was examined with the Maxicell system. The product specified by the plasmids in E. coli cells was immunologically identified to be tuna GH.

Amino Acid Sequence↗
PubMed1988

[A case of pheochromocytoma associated with von Recklinghausen's disease].

A case of pheochromocytoma associated with von Recklinghausen's disease is reported. A 53-year-old man consulted the Department of Dermatology of our hospital because of Dermatoptosis in the breast and abdomen. He asked to resect of the mass. Blood bio chemistry findings were almost within normal limits but only catecholamines in serum and urine were remarkably higher. With a result of other detailed examinations, he was diagnosed as pheochromocytoma. He was referred to our clinic. Laparotomy was carried out under the strict monitoring of the circulation. We diagnosed his clinical status to non-hypertensive type. The tumor was 2.5 x 1.7 x 1.7 cm in size and weighed 10 g. After operation, serum and urine catecholamines returned to all within normal limits. a operation for the dermatoptosis was performed afterwards at the Department of Dermatology.

Adrenal Gland Neoplasms↗
PubMed1988

[Reduced operation for rectal cancer].

The effectiveness of extended dissection of higher-ranked lymph nodes in patients with rectal cancer has been well recognized recently. However, to prevent postoperative bladder and sexual dysfunction, reduced lymphadenectomy and autonomic nerve preservation are necessary. By definition a reduced operation for rectal cancer attempts to preserve the autonomic nerve and the levator ani muscles without hampering recovery. To clarify the indication of reduced operation for rectal cancer, 219 patients with rectal cancer who underwent resections at our hospital between 1980 and 1986 were analyzed. The relationship of the depth of tumor invasion through the bowel wall to lymph node metastasis in rectal cancer was examined. In cases of rectal cancer limited to submucosa or muscularis propria, the degree of metastatic spread was n0 or n1 (+). In the cases of rectal cancer invading subserosa, serosa or contiguous structures, the degree of metastatic spread was n3(+) or n4(+). Concerning the relationship of the histopathological type and 5-year survival rate, the corrected 5-year survival rate was 72.46% in cases of well and moderately differentiated adenocarcinoma, and 48.84% in cases of poorly differentiated adenocarcinoma and undifferentiated carcinoma. From these results, reduced lymph node dissection and autonomic nerve preservation are possible in patients with well and moderately differentiated adenocarcinoma with invasion into the mucosa, submucosa and muscularis propria.

Humans↗
PubMed1987

The expression of functional erythropoietin receptors on an interleukin-3 dependent cell line.

We report the expression of the erythropoietin receptors on an interleukin-3 dependent cell line. By the transfer into medium supplemented with erythropoietin, DA-1 cells were converted to an erythropoietin dependent growth state. [125I] erythropoietin was used to detect receptors specific for this hormone on the cell surface. Binding studies revealed that erythropoietin bound to 131 +/- 23 receptors/cell with a Kd of 0.54 +/- 0.2 nM. When the cells were incubated at 37 degrees C, trichloroacetic acid soluble radioactivity appeared in the medium after [125I] erythropoietin binding began to decrease, suggesting that the decline represents the degradation of cell associated [125I] erythropoietin- receptor complexes.

Cell Line↗
PubMed1987

A short amino-terminal segment of microsomal cytochrome P-450 functions both as an insertion signal and as a stop-transfer sequence.

Co-translational insertion of liver microsomal cytochrome P-450 into the endoplasmic reticulum membrane is mediated by the signal recognition particle (SRP) and the presence in the cytochrome molecule of a signal sequence that can be recognized by SRP has been postulated. To locate this signal sequence, six hybrid cDNAs were constructed in which various segments of a cDNA for a rabbit liver cytochrome P-450 are fused with a cDNA or its fragment encoding yeast porin (an outer mitochondrial membrane protein) or with a cDNA for pre-interleukin 2 (a secretory protein) from which the 5'-terminal portion encoding most of its signal sequence had been removed. These hybrid cDNAs were inserted into an SP-6 transcription vector and transcribed in vitro. The mRNAs thus synthesized were translated in a cell-free system in the presence of rough microsomes. It was thus found that only those chimeric proteins containing (at their amino-terminal end) the amino-terminal cytochrome P-450 segments consisting of greater than or equal to 29 amino acid residues were co-translationally inserted into the membrane in an SRP-dependent fashion. These proteins were, however, neither processed nor translocated across the membrane. These findings, coupled with the observation that the major portion of these proteins, when inserted into the membrane, was degraded by trypsin, led to the conclusion that a short amino-terminal segment (less than 29 residues) of the cytochrome P-450 functions not only as an insertion signal but also as a stop-transfer sequence. This segment is, therefore, similar to the internal signal of type II plasma membrane proteins, but differs from the latter in the topogenic function.

Amino Acid Sequence↗
PubMed1987

Fluorometric enzyme-linked immunosorbent assay for the measurement of IgE antibody to mite Dermatophagoides farinae.

We have developed a fluorometric enzyme-linked immunosorbent assay for measuring IgE antibody to Dermatophagoides farinae. Polystyrene microplates were coated with proteins extracted from the mites. The IgE antibody which attached to the solid-phase antigen was detected by anti-IgE antibody conjugated with beta-galactosidase. Four-methylumbelliferyl-beta-D-galactoside was used as the enzyme substrate and the fluorescence intensity of the reaction product was measured. The antibody levels determined by this method well correlated with those determined by the radioallergosorbent test (RAST). This method is simpler and less expensive to carry out than the RAST when dealing with a large number of serum specimens for seroepidemiological studies of asthma and nasal allergy.

Adolescent↗
PubMed1987

Human erythropoietin stimulates murine megakaryopoiesis in serum-free culture.

Recombinant erythropoietin (Epo) was capable of stimulating murine megakaryopoiesis both in serum-containing and serum-free cultures, although a relatively high amount of Epo was necessary to provide sufficient stimulus for colony growth. This observation was further confirmed by experiments using nonadherent, nonphagocytic, and T-cell-depleted marrow cells in which Epo stimulated the growth of single megakaryocytes, as well as clusters or colonies. Total plate analysis revealed that twice as many single megakaryocytes and two-cell aggregates were generated by Epo than generated by pokeweed mitogen-stimulated spleen cell-conditioned medium (PWM-SCM). The number of colonies with four or more cells formed by PWM-SCM, however, was significantly higher than that generated by Epo. These results suggest that in comparison to the factor(s) in PWM-SCM, Epo stimulates the growth of more mature progenitors.

Animals↗