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Y Matsubayashi

Publications and source records attributed to Y Matsubayashi.

At least 37 records · Page 2Linked to original sources
PubMed1998

Differential induction by methyl jasmonate of genes encoding ornithine decarboxylase and other enzymes involved in nicotine biosynthesis in tobacco cell cultures.

A cDNA of tobacco BY-2 cells corresponding to an mRNA species which was rapidly induced by methyl jasmonate (MeJA) in the presence of cycloheximide (CHX) was found to encode ornithine decarboxylase (ODC). Another cDNA from a MeJA-inducible mRNA encoded S-adenosylmethionine synthase (SAMS). Although these enzymes could be involved in the biosynthesis of polyamines, the level of putrescine, a reaction product of ODC, increased slowly and while the levels of spermidine and spermine did not change following treatment of cells with MeJA. However, N-methylputrescine, which is a precursor of pyrrolidine ring of nicotine, started to increase shortly after MeJA-treatment of cells and the production of nicotine occured thereafter. The levels of mRNA for arginine decarboxylase (ADC), an alternative enzyme for putrescine synthesis, and that for S-adenosylmethionine decarboxylase (SAMDC), required for polyamine synthesis, were not affected by MeJA. In addition to mRNAs for ODC and SAMS, mRNA for putrescine N-methyltransferase (PMT) was also induced by MeJA. Unlike the MeJA-induction of ODC mRNA, MeJA-induction of SAMS and PMT mRNAs were blocked by CHX. The level of ODC mRNA declined after 1 to 4 h following MeJA treatment, while the levels of mRNAs for SAMS and PMT continued to increase. Auxin significantly reduced the MeJA-inducible accumulation of mRNAs for ODC, SAMS and PMT. These results indicate that MeJA sequentially induces expression of a series of genes involved in nicotine biosynthesis by multiple regulatory mechanisms.

Acetates↗
PubMed1998

[Cystic vein: as a perfusion vein of hepatic portion-angiographical study].

In order to determine the hepatic portions by cystic vein, we carried out abdominal angiography in 153 patients. The cystic vein was recognized in eleven patients, but only in nine cystic venous flow could be measured. In this group of patients, in which the cystic venous flow was detected, hepatic angiography was performed through the right hepatic artery (RHA) in six patients, the anterior branch of RHA in one patient, and the cystic artery in two patients. Simultaneously, angiographical CT was performed in five patients. As the results, it is presumed that the cystic venous flow perfused segment 4 portal branch (P4) + segment 5 (S5) in four patients, P4 in two patients, segment 6 portal branch (P6), S5 + right portal vein (RPV) + right hepatic vein (RHV), and S5 + RHV in one patient, respectively, and we concluded that in 70% of cases cystic venous flow perfused either P4 or S5.

Cysts↗
PubMed1997

Phytosulfokine-alpha, a sulfated pentapeptide, stimulates the proliferation of rice cells by means of specific high- and low-affinity binding sites.

Peptide growth factors were isolated from conditioned medium derived from rice (Oryza sativa L.) suspension cultures and identified to be a sulfated pentapeptide [H-Tyr(SO3H)-Ile-Tyr(SO3H)-Thr-Gln-OH] and its C-terminal-truncated tetrapeptide [H-Tyr(SO3H)-Ile-Tyr(SO3H)-Thr-OH]. These structures were identical to the phytosulfokines originally found in asparagus (Asparagus officinalis L.) mesophyll cultures. The pentapeptide [phytosulfokine-alpha (PSK-alpha)] very strongly stimulated colony formation of rice protoplasts at concentrations above 10(-8) M, indicating a similar mode of action in rice of phytosulfokines. Binding assays using 35S-labeled PSK-alpha demonstrated the existence of both high- and low-affinity specific saturable binding sites on the surface of rice cells in suspension. Analysis of [35S]PSK-alpha binding in differential centrifugation fractions suggested association of the binding with a plasma membrane-enriched fraction. The apparent Kd values for [35S]PSK-alpha binding were found to be 1 x 10(-9) M for the high-affinity type and 1 x 10(-7) M for the low-affinity type, with maximal numbers of binding sites of 1 x 10(4) sites per cell and 1 x 10(5) sites per cell, respectively. Competition studies with [35S]PSK-alpha and several synthetic PSK-alpha analogs demonstrated that only peptides that possesses mitogenic activity can effectively displace the radioligand. These results suggest that a signal transduction pathway mediated by peptide factors is involved in plant cell proliferation.

Binding Sites↗
PubMed1996

Active fragments and analogs of the plant growth factor, phytosulfokine: structure-activity relationships.

Sulfated pentapeptide phytosulfokine-alpha (PSK-alpha) is the first chemically characterized peptidal plant growth factor that induces proliferation of the mesophyll cells of asparagus. To determine the active core involved in the sequence PSK-alpha, we synthesized PSK-alpha and twelve PSK-alpha analogs by the solid phase peptide synthesis and the direct sulfation to the peptide-resin using dimethylformamide-sulfurtrioxide (DMF-SO3) complex. The truncated analogs of PSK-alpha without the first and second C-terminal amino acids retained 8% and 20% of the activity of the parent pentapeptide, respectively. Deletion of the sulfate groups of Tyr1 and Tyr3 resulted in compounds with 0.6% and 4% of the activity of PSK-alpha, indicating that the sulfate group of Tyr1 is more important than that of Tyr3 for the expression of its activity. In contrast, the N-terminal truncated analog and unsulfated analog exhibited little or no activity. Thus the N-terminal tripeptide fragment H-Tyr(SO3H)-Ile-Tyr(SO3H)-OH has been identified as the active core of PSK-alpha.

Amino Acid Sequence↗
PubMed1996

Phytosulfokine, sulfated peptides that induce the proliferation of single mesophyll cells of Asparagus officinalis L.

Proliferation of dispersed plant cells in culture is strictly dependent on cell density, and cells in a low-density culture can only grow in the presence of conditioned medium (CM). No known plant hormones have been able to substitute for CM. To quantify the mitogenic activity of CM, we examined conditions for the assay system using mechanically dispersed mesophyll cells of Asparagus officinalis L. and established a highly sensitive bioassay method. By use of this method, the mitogenic activity of CM prepared from asparagus cells was characterized: it was heat-stable, susceptible to pronase digestion, and resistant to glycosidase treatment. On the basis of these results, the mitogenic activity in CM was purified 10(7)-fold by column chromatography, and two factors named phytosulfokine-alpha and -beta (PSK-alpha and PSK-beta) were obtained. By amino acid sequence analysis and mass spectrometry, the structures of these two factors were determined to be sulfated pentapeptide (H-Tyr(SO3H)-Ile-Tyr(SO3H)-Thr-Gln-OH) and sulfated tetrapeptide (H-Tyr(SO3H)-Ile-Tyr(SO3H)-Thr-OH). PSK-alpha and PSK-beta were prepared by chemical synthesis and enzymatic sulfation. The synthetic peptides exhibited the same activity as the natural factors, confirming the structure for PSK-alpha and PSK-beta mentioned above. This is the first elucidation of the structure of a conditioned medium factor required for the growth of low-density plant cell cultures.

Amino Acid Sequence↗
PubMed1996

Elevation of lymphocyte and hematopoietic stem cell numbers in mice transgenic for human granulocyte CSF.

Transgenic mice expressing human granulocyte colony stimulating factor (hG-CSF) were bred to establish an experimental model for studying the biologic function of hG-CSF. The mice produced approximately 1000 pg/ml of hG-CSF in sera and expressed hG-CSF mRNA in all of the tissues examined. Granulocytosis and elevation of hematopoietic precursor number were observed in hematopoietic tissues as expected, but lymphocytosis with 5-fold increase in peripheral blood and 2-fold increase in spleen was also evident. Hematopoietic stem cells capable of reconstituting lethally irradiated recipient mice were abundant in the circulation of these transgenic mice. No disadvantageous tissue damage was observed when various organs were analyzed. As shown in this study, G-CSF has a stimulating effect on lymphopoiesis when it is expressed in a certain condition. The lymphocytosis, as well as the high level of hematopoietic stem cell mobilization into circulation, indicates a wider range of potential G-CSF activity than expected. The mice transgenic for hG-CSF described herein will contribute greatly to the understanding of the regulatory mechanism in hematopoiesis.

Animals↗
PubMed1994

Expressed sequence tags from cultured cells of rice (Oryza sativa L.) under stressed conditions: analysis of transcripts of genes engaged in ATP-generating pathways.

Large-scale sequencing of randomly selected cDNA clones was used to isolate numerous genes in rice (Oryza sativa L.). Total RNA used for cDNA synthesis was prepared from suspension-cultured cells of rice grown under stressed conditions, such as in saline or nitrogen-starvation conditions. A total of 780 cDNA clones were partially sequenced and about 15% could be identified as putative genes. In the library constructed under saline conditions, we identified several genes associated with signal transduction, such as protein kinase and small GTP-binding protein genes. Many stress-related genes were isolated from both the saline and nitrogen-starvation libraries. These results indicate that stress treatment of suspension-cultured cells makes it possible to efficiently isolate various types of plant genes. To examine the usefulness of such tagged cDNAs for the study of gene expression in a specific metabolic pathway, we analyzed mRNA levels of genes engaged in the ATP-generating pathways in cultured cells of rice under different stresses, such as 20% sucrose, salt stress, cold stress and nitrogen-starvation stress. The results suggest that the coordinated induction of several genes in key steps under stressed conditions may be essential for activation of the entire energy-producing pathway to maintain homeostasis in rice cells. Expressed sequence tags identified by random cDNA sequencing provide the opportunity to generate a transcript map of rice genes.

Adaptation, Biological↗
PubMed1994

Malignant lymphoma in the ileocecal region causing intussusception.

A 67-year-old female was admitted with diarrhea. Preoperatively, we diagnosed intussusception due to malignant lymphoma in the ileocecal region by image and colonoscopic examinations. We resected the right hemicolon for the tumor, which was located mainly in the cecum, causing intussusception. The stenotic terminal ileum free of the tumor was invaginated within the cecum with infiltrating tumor, thus showing the appearance of an anthill. The growth of the tumor corresponded with Wood's constrictive type, in which intussusception rarely occurs.

Aged↗
PubMed1994

Effects of non-MHC background genes on the induction of CD4+ T cells that prevent rejection of a highly immunogenic tumor, FBL-3.

This study showed that non-MHC genes common to (DBA/2 H-2d) and (DBA/1 H-2q) gave rise to suppressor T (Ts) cells in the hybrid F1 mice between C57BL/6 (B6) strain in the anti-FBL-3 tumor responses. FBL-3, a Friend virus-induced tumor cell line of B6 mouse origin, is highly immunogenic as shown by findings that syngeneic and hybrid F1 mice with several other inbred strains rejected up to 3 x 10(7) tumors cell inoculated s.c. and generated potent CTL responses after mixed lymphocyte tumor cell culture. In contrast to these mice, (B6 x DBA/2) and (B6 x DBA/1)F1 mice did not reject the tumor as the tumor doses increased. Progressive tumor growth in these F1 mice was blocked by an i.p. injection of cyclophosphamide (250 mg/kg) on day 10, but not on day 5, after tumor cell inoculation. Anti-CD4 (GK1.5) mAb exerted similar therapeutic effects against tumor when given twice, between day 0 and 10, whereas the additional injection of anti-CD8 mAb enhanced the tumor growth in mice that otherwise rejected the tumor. Thus, in the response of (B6 x DBA/2)F1 mice to FBL-3 tumor cells, CD4+ Ts seemed to down-regulate the immunologically mediated regression of the tumor produced by CD8+ CTL. This was evidenced by limiting dilution culture analyses, which showed that the frequency of an FBL-3-specific CTL precursor in the (B6 x DBA/2)F1 mice that rejected the tumor with anti-CD4 mAb was approximately 7- to 9-fold higher than that in mice in which the tumor regressed spontaneously.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Prognostic factors and the significance of gastrectomy in gastric lymphoma].

Fifty cases of primary gastric lymphoma treated at Tenri Hospital between 1975 and 1992 were reviewed retrospectively. Histopathologically they were classified according to the Working Formulation into three groups: low grade 3 cases, intermediate grade 42 of which 34 were diffuse large cell and high grade 5. Their clinical stages according to the Ann Arbor staging system were as follows; Stage I 15 cases, Stage II 17, Stage III 5 and Stage IV 13. Twelve variables were tested by univariate analysis for prognosis. Significant prognostic factors were clinical stage, tumor depth to the gastric wall, regional lymph node involvement, macroscopic finding of tumor shape and surgical resectability. Important variables were tested by using a multiple regression, the 5 most significant variable being curative surgical resection. The year survival after curative resection was 93.8% and 25.2% for other patients (p < 0.001). In the patients with Stage II-disease, the greater the 'N-number' of regional lymph node involvement according to the General Rules for the Gastric Cancer Study was, the lower the survival rate was due to the difficulty for curative resection (p < 0.05). The same curative resection is necessary for gastric lymphoma as for gastric cancer. In the patients with Stage III or IV disease, higher survival rate was achieved in the gastrectomy group than the others. In conclusion, an aggressive surgical intervention is warranted in the treatment of gastric lymphoma of any stage.

Adolescent↗
PubMed1993

Multiplicity of virus-encoded helper T-cell epitopes expressed on FBL-3 tumor cells.

To identify retroviral antigenic determinants recognized by CD4+ T helper cells during tumor rejection, we established four noncytolytic, helper-type, CD4+ T-cell clones by limiting dilution cultures of mixed lymphocyte-tumor cultures from mice immune to a Friend virus-induced tumor, FBL-3. Among these, three T helper cell clones were isolated from C57BL/6 mice and the fourth was isolated from a (BALB/c x C57BL/6)F1 mouse. All these clones proliferated in response to the immunizing FBL-3 tumor cells in a major histocompatibility complex class II-restricted manner. Each clone expressed a distinct T-cell receptor with a characteristic combination of alpha and beta chains. The localization of helper T-cell determinants on viral proteins was analyzed with recombinant vaccinia viruses expressing Friend murine leukemia virus (F-MuLV) gag or env genes or shorter fragments of the env gene. Epitopes recognized by these T-cell clones were mapped to at least two distinct portions in the env region of the F-MuLV genome. These epitopes were identified more precisely with synthetic peptides derived from the F-MuLV envelope protein sequence. One of these epitopes was common to Friend and Moloney MuLVs and was located in the N-terminal region of the gp70 glycoprotein at amino acids 122 to 141. The second epitope, which was recognized in the context of hybrid I-Eb/d major histocompatibility complex class II molecule, was located close to the C-terminal end of gp70 at amino acids 462 to 479. In addition, a possible third epitope was located in the N-terminal half of the gp70 sequence and differed from the first epitope in that it was not cross-reactive with the Moloney MuLV envelope protein.

Amino Acid Sequence↗
PubMed1992

Expression pattern of SR alpha promoter in human embryonal carcinoma and transgenic tissues in mice.

Human embryonal carcinoma is thought to be a counterpart of mouse embryonal carcinoma, which has provided useful information for studying early molecular events in murine embryogenesis. A major practical problem in the use of human embryonal carcinoma for molecular pathological studies is the lack of an efficient expression system for foreign genes. The SR alpha promoter is a fusion promoter containing the SV 40 early promoter and the R segment and part of the U5 sequence of the long terminal repeat derived from human T-cell leukemia virus type I. We analyzed the expression pattern of the SR alpha promoter in human and mouse embryonal carcinoma lines and transgenic mouse tissues. Efficient and stable expression was detected in all cell lines tested, and tissues from all mice of four independent transgenic lines carrying the SR alpha-CAT vector showed a detectable level of CAT expression. These data suggest that the SR alpha promoter is useful for studies of both human embryonal carcinoma and transgenic mouse tissue. Using this expression system, we are now able to label human embryonal carcinomas with various genes, for example beta galactosidase, and follow their fate at the single-cell level in nude mice, where xenotransplanted human embryonal carcinoma expresses differentiation capability.

Animals↗
PubMed1992

Spatial and temporal differing control of sympathetic activities during hemorrhage.

We performed simultaneous multifiber recordings of cardiac, renal (RNA), hepatic (HNA), adrenal, and splenic sympathetic nerve activities during 10 min of sustained hemorrhagic hypotension to a mean blood pressure of 50 mmHg. One minute after bleeding in dogs with intact baroreceptors, all measured nerve activities increased significantly, and a gradual decline toward prebleeding level followed. Only RNA showed a great inhibition below prebleeding level. In cervically vagotomized dogs, all nerve activities showed significantly higher levels than prebleeding control throughout the experiment. The initial increase in HNA observed at 1 min postbleeding in animals with intact baroreceptors was attenuated. HNA in the vagotomized group showed a gradual increase so that 5 min postbleeding, HNA reached a peak level that was maintained until the end of the experiment. Sympathoinhibition in RNA and decrease in heart rate during hemorrhagic hypotension were reversed to significant increases after vagotomy. In contrast, animals with denervation of the carotid sinus and aortic nerves showed initial increases in nerve activities followed by recovery to prebleeding control level within 2 min postbleeding. After complete denervation of systemic baroreceptors, rapid hemorrhage did not cause any significant change in sympathetic nerve activity in any nerve. These results indicate that early reflex response to hemorrhage in regional sympathetic nerves is unidirectional sympathoexcitation mediated by summative unloading of both arterial baroreceptors and cardiopulmonary receptors. When greater than 1 min passed after bleeding and sustained hypotension of 50 mmHg was established, a reflex mechanism through the vagal afferents participated to inhibit the unidirectional sympathoexcitation mediated by unloading of arterial baroreceptors, with different magnitude in different innervated organs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗
PubMed1992

[Endosonographic diagnosis of metastatic tumors in the recto-uterine or recto-vesical space by transrectal scan].

A 6-year experience of transrectal ultrasonography (TRUS) in 75 patients with advanced gastrointestinal cancers was reviewed regarding the diagnostic yield of metastatic extrarectal tumors. A diagnostic capability of TRUS (a sensitivity of 82.9%, a specificity of 97.5% and an accuracy of 90.7%) was statistically superior to that of digital rectal examination (a sensitivity of 62.9%, a specificity of 75% and an accuracy of 69.3%). However, TRUS could hardly correctly diagnose a miliary type of extrarectal tumors in contrast to nodular and thickened types. TRUS also had an advantage over conventional ultrasonography in detecting a small amount of ascites with a sensitivity of 75%, a specificity of 93% and an accuracy of 86.6%. Patients with positive signs of extrarectal tumors or ascites on TRUS survived significantly shorter than those with negative signs. TRUS renders a convenient means in the objective diagnosis of peritoneal carcinomatosis, and predicts patient's prognosis.

Adult↗
PubMed1991

Conserved V(D)J junctional sequence of cross-reactive cytotoxic T cell receptor idiotype and the effect of a single amino acid substitution.

A dominant T cell population bearing the cross-reactive idiotype of T cell antigen receptor (TcR) has been obtained using an anti-TcR monoclonal antibody (mAb) developed in syngeneic mice. Forty-four cytotoxic T cell (CTL) clones with reactivity to a mAb (N9-127) were selected out of 396 H-2Db-restricted CTL clones specific for FBL-3 tumor antigen from C57BL/6 mice. These CTL clones were divided into two groups according to the blocking pattern of cytotoxic activities with mAb N9-127. All eight CTL clones chosen from both groups expressed TcR with a specific combination of alpha and beta chains (V alpha 1J alpha 112-2/V beta 10D beta 2.1J beta 2.7), and the difference in the blocking susceptibility resided in a single amino acid substitution (Gly to Asp) in the D-J joint of beta chain. This provides direct evidence for the molecular basis of cross-reactive idiotypes of TcR recognized by mAb.

Amino Acid Sequence↗
PubMed1991

Isopropylidine maltoheptosyl fructofuranoside, doubly blocked substrate for determination of endoamylase activity.

We synthesized o-(4,6-o-isopropylidene-alpha-D-glucopyranosyl)-(1----4)- [o-alpha-D-glucopyranosyl-(1----4])5-o-alpha-D-glucopyranosyl-(1----2)- alpha-D-fructofuranoside (IPG7F) and developed an assay for determining the activity of amylase in human serum and urine by using this substrate. Glucoamylase, alpha-glucosidase, and mannitol dehydrogenase are used as coupling enzymes. The coupled reactions are monitored by continuously measuring the oxidation rate of NADH. In this procedure, various substances in the test specimens do not interfere with the detection of amylase activity. Exactly one molecule of NADH is oxidized by one attack of amylase on the substrate, although four products can be produced in the reaction. The within-assay coefficient of variation (CV) ranged from 1.0% to 4.1% and the between-assay CV ranged from 2.6% to 5.3%. The results of our new assay correlate well with those of the amylase assay involving p-nitrophenol maltoheptaoside as substrate (r = 0.978) and with those of the amylase assay involving maltopentaose (r = 0.987).

Alkenes↗
PubMed1991

[Isolated gingival relapse during hematological remission in a patient with erythroleukemia].

A 54-year-old man was admitted to Kitano Hospital because of nuchal pain in November, 1984. The bone marrow was hypercellular with 18% of myeloblasts and 45% of erythroblasts many of which were megaloblastoid and positive for PAS-staining. BH-AC . DMP therapy induced a complete remission which was maintained for more than 3 years until April, 1988, when gingival swelling occurred. A biopsy of the gingiva revealed a diffuse infiltration of myeloblasts together with a few erythroblasts. Local irradiation resulted in he disappearance of the swelling. However, the microscopic infiltration of the leukemic cells in the gingiva still remained in December, 1988 when there was no apparent gingival swelling and the patient was in a second hematological remission. Bone marrow relapse occurred in September, 1988 and twice thereafter. Complete remissions were again achieved for the first two relapses and the leukemic infiltration of the gingiva disappeared after another irradiation. The third relapse was refractory to an intensive chemotherapy and the gingival swelling also recurred in July, 1989. The patient died of pneumonia in October, 1989. The gingiva may be more common site of extramedullary relapse. Careful observation of this organ would be necessary throughout the course of leukemias.

Antineoplastic Combined Chemotherapy Protocols↗