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T Taki

Publications and source records attributed to T Taki.

At least 145 records · Page 8Linked to original sources
PubMed1995

Direct mass spectrometric analysis of glycosphingolipid transferred to a polyvinylidene difluoride membrane by thin-layer chromatography blotting.

A simple, rapid method for the analysis of glycosphingolipid that combines "thin-layer chromatography (TLC) blotting" and mass spectrometry is reported. Glycosphingolipids developed by TLC were transferred to a polyvinylidene difluoride membrane by TLC blotting, after which the glycosphingolipid band on the membrane was excised and placed on a mass spectrometer probe tip, and a few microliters of triethanolamine was added as the matrix. The sample was analyzed by secondary ion mass spectrometry. About 1 microgram of glycosphingolipid subjected to TLC can be analyzed. The major advantage of this method is that glycosphingolipid can be analyzed structurally without purification by repeated column chromatography.

Animals↗
PubMed1995

Accumulation of isogloboside and ganglio-N-tetraosyl ceramide having blood group B determinant in the hepatomas of female LEC rats.

We have studied the neutral glycolipid composition of spontaneous hepatomas in LEC female rats. Neutral lipid fractions were isolated and purified by column chromatographies on DEAE-Toyopearl 650(M) and Iatrobeads. The neutral glycolipid fraction contained 3.2 to 4.4 micrograms lipid-bound glucose (Glc) per mg protein, and consisted of isogloboside (iso-Gb4, 50.8% of total neutral glycolipids) and IV3Gal, IV2Fuc, GgOse4Cer (asialo-BGM1, 13.5%) as the major neutral glycolipids and Gb3 and iso-Gb3 (9.2%), GlcCer (7.2%), LacCer (6.1%) as the other species. The structure of iso-Gb4 was elucidated by gas-liquid chromatography (GLC), permethylation study, liquid secondary ion (LSI) mass spectrometry, and nuclear Overhauser enhancement spectroscopy (NOESY) and that for asialo-BGM1 by GLC, LSI mass spectrometry, and high-performance thin-layer chromatography (HPTLC)-overlay method using anti-asialo-BGM1 antibody. Isogloboside and asialo-BGM1 which are found in negligible amounts in normal liver tissues may represent excellent markers for studying tumor metastasis and cellular adhesion.

ABO Blood-Group System↗
PubMed1995

An improved assay method for the measurement and detection of sphingomyelinase activity.

We have developed an improved assay method to measure sphingomyelinase activity and to detect this enzyme separated on polyacrylamide gels. The assay of sphingomyelinase activity involved immobilizing [N-methyl-14C]sphingomyelin on polyvinyldiflouride (PVDF) membrane, incubation with sphingomyelinase, and the measurement of radioactivity associated with [14C]phosphocholine. The enzyme activity was dependent on the concentration of sphingomyelin, enzyme, pH, and temperature. Thirty minutes of incubation time was optimal for enzyme activity. This enzyme had a bimodal pH optima, in that optimum enzyme activity was measured at pH 5.4 and 7.4. The detection of sphingomyelinase was pursued by separating the enzyme on a polyacrylamide gel and carrying out the enzyme assay by exposure to [14C]sphingomyelin blotted on a PVDF membrane. The enzyme activity on the PVDF membrane was visualized by autoradiography. A white band (depicting hydrolytic removal of [14C]sphingomyelin from PVDF was observed. Our method of detecting sphingomyelinase by immobilizing sphingomyelin on PVDF membrane may serve as a prototype for assaying various other enzymes in which the hydrolytic product is released into the aqueous phase. Moreover, our method for detecting sphingomyelinase on polyacrylamide gels may be helpful in further studies on the molecular biochemistry of this and related phospholipases.

Acrylic Resins↗
PubMed1995

Transformation of type 1 astrocytes with N-ethyl-N-nitrosourea: establishment of an in vitro system and the role of the p53 gene.

N-ethyl-N-nitrosourea (ENU)-induced gliomas, animal models of human gliomas, are most frequently oligodendrocytic, while human gliomas tend to be astrocytic. To facilitate a detailed study of human glial carcinogenesis, we developed an in vitro system using type 1 astrocyte transformation with ENU. Type 1 astrocytes from fetal Wistar rat brain were treated by a single dose of ENU. Transformed colonies appeared 50 days after exposure to single doses of ENU greater than 150 micrograms/mL. Cloned cells from these colonies retained the immunohistochemical characteristics of type 1 astrocytes. They showed rapid growth and high saturation densities, colony formation in low (2%) serum medium and gave rise to tumors when injected into nude mice. When p53 expression was studied at each passage, a single cell positive for mutant p53 protein emerged 40 days after ENU treatment. In the next 1-3 passages, the mutant p53 positive cell formed piled-up colonies and exhibited dominant growth. Northern blot analysis showed markedly increased accumulations of p53 mRNA in transformed cells. This in vitro transformation system of type 1 astrocytes provides a valuable tool for further investigations of astrocyte carcinogenesis.

Animals↗
PubMed1995

Ganglioside-like epitopes of lipopolysaccharides from Campylobacter jejuni (PEN 19) in three isolates from patients with Guillain-Barré syndrome.

Sera from patients with Guillain-Barré syndrome (GBS) frequently have anti-GM1 antibody. We earlier showed that an lipopolysaccharides (LPS) from Campylobacter jejuni (PEN 19) isolated from a GBS patient has a GM1 ganglioside-like structure. Aspinall et al. (Biochemistry, 61 (1994) 335-337) reported that OH 4382 has an LPS that bears a CD3 ganglioside-like structure and that OH 4384 has an LPS that bears a GT1a-like structure; both strains were isolated from patients with GBS. They also suggested a GM1-like structure is present in the LPSs from OH 4384, but failed to show the presence in the LPSs from OH 4382. To clarify the pathogenesis of GBS after infection by C. jejuni (PEN 19), we investigated the carbohydrate structures of the three strains by thin-layer chromatography immunostaining with cholera toxin and monoclonal anti-ganglioside antibodies. We found that both OH 4382 and OH 4384 have an LPS with the GM1 epitope as well as one with the GT1a or GD3 epitope.

Antibodies, Bacterial↗
PubMed1995

Subclass of IgG antibody to GM1 epitope-bearing lipopolysaccharide of Campylobacter jejuni in patients with Guillain-Barré syndrome.

Sera of patients who develop Guillain-Barré syndrome (GBS) subsequent to Campylobacter jejuni enteritis frequently have IgG anti-GM1 antibody. Lipopolysaccharide (LPS) of C. jejuni isolated from a GBS patient has a GM1 ganglioside-like structure. IgG subclass distribution of the anti-GM1 antibody in GBS patients is mainly restricted to IgG1 and IgG3. Since IgG antibodies to bacterial polysaccharide generally are restricted to IgG2 subclass, some investigators have assumed that either the general rules for immune response to LPS are broken in the patients or an alternative antigen has yet to be identified. To clarify whether the LPS participates in the production of the anti-GM1 antibody, we investigated the subclass of IgG antibody to the LPS that bears GM1-like structure. The subclasses of IgG antibody to the LPS were restricted predominantly to IgG1 and IgG3. The GM1 epitope-bearing LPS may function in the production of the anti-GM1 antibody in patients with GBS subsequent to C. jejuni infection.

Campylobacter jejuni↗
PubMed1995

A novel function of islet-derived CD8+T cells in initiating and developing autoimmune insulin-dependent diabetes mellitus in non-obese diabetic (NOD) mice.

Accumulated studies revealed that CD4+T cells were initially required for diabetes in NOD mice, whereas interaction of CD4+T/CD8+T cells is not fully understood. To address this question, we established islet-derived CD4+T cells and CD8+T cells from NOD mice. One NOD neonate that received CD4+T cells developed diabetes and insulitis with CD8+T cells. Administration of cyclophosphamide to non-diabetic recipients accelerated the development of diabetes, while none of the mice with anti-CD8 antibody did so. Similarly, it was observed that neonates that received islet-derived CD8+T cells developed diabetes and obvious insulitis mainly with CD4+T cells. Administration of anti-CD4 antibody with transfer of CD8+T cells inhibited insulitis. These results imply that CD8+T cells function as an initial element to recruit CD4+T cells to islets as well as a final effector.

Animals↗
PubMed1995

Cell therapy with encapsulated xenogeneic tumor cells secreting beta-endorphin for treatment of peripheral pain.

The purpose of this study was to assess whether xenogeneic tumor cells secreting beta-endorphin and immunologically isolated in polymer capsules could survive and continue to reduce pain when transplanted into the spinal cerebro-spinal fluid (CSF) space of rats. Also, a silicone container for polymer capsules was designed for the clinical application of this method of cell therapy. The mouse tumor cell lines, proopiomelanocortin gene transfected Neuro2A which secrete beta-endorphin, were enclosed in polymer capsules at a density of 5 x 10(6)/mL, and transplanted into the spinal CSF space from the occipito-atlantal junction of male Sprague-Dawley rats. Three analgesiometric tests--the tail pinch test, the hot plate test, and electrical stimulation test--showed that the rats with encapsulated Neuro2A (n = 6) were significantly less sensitive to pain after transplantation than control animals (n = 8). The analgesia induced by the encapsulated cells secreting beta-endorphin was attenuated by the opiate antagonist naloxone. Morphological study revealed that the encapsulated cells survived for 1 mo after transplantation into the CSF space. An in vitro experiment on cultured capsules (3 cm long) with a silicone container (Kaneka Medics Co) showed that the encapsulated Neuro2A (5 x 10(6) mL) could secrete peptides for 1 mo. The results of this study indicate that immunologically isolated xenogeneic tumor cells can secrete opiate in the CSF space, and that a silicone container may help the application of this method to the treatment of cancer pain.

Adrenocorticotropic Hormone↗
PubMed1995

Identification of phosphocholine-containing glycoglycerolipids purified from Mycoplasma fermentans-infected human helper T-cell culture as components of M. fermentans.

Previously, we have reported the occurrence of novel phosphocholine-containing glycoglycerolipids (GGPLs: GGPL-I and GGPL-III) in human helper T-cell (MT-4 cell line) (Mustuda et al, Glycoconjugate J. 10:340). However, the GGPLs disappeared from the MT-4 after treatment with an antimycoplasma agent. This disappearance suggested the involvement of microorganisms in the GGPL expression. In this paper, we show that the novel lipids are components of Mycoplasma fermentans itself. The supernatant fluid of the antimycoplasma agent-untreated Mt-4 cell culture produced mycoplasma-like colonies on PPLO agar plates, and PCR and immunological methods revealed the presence of M. fermentans. GGPLs were expressed again in the treated Mt-4 cells after infection with the isolated M. fermentans. The isolated M. fermentans had glycoglycerolipids corresponding to GGPL-I and GGPL-III. Thin-layer chromatography-mass spectrometry and immunological analyses showed that these glycoglycerolipid which were derived from the isolated M. fermentans were identical with GGPL-I and GGPL-III previously obtained. This is the first report that shows mycoplasma has phosphocholine-containing glycoglycerolipids.

Animals↗
PubMed1995

Effect of fluoride on the activities of the Na+/glucose cotransporter and Na+/K(+)-ATPase in brush border and basolateral membranes of rat kidney (in vitro and in vivo).

In this study, renal Na+/K(+)-ATPase activity was demonstrated to be strongly suppressed prior to the glucosuria caused by a fluoride dose (NaF 35 mg/kg, i.p.), and the 50% suppression of the enzyme activity was almost at the same dose of NaF, about 30 mg/kg, i.p. to rats. In the rats, renal Na+/glucose cotransporter activity in brush border membranes was not affected by in vivo NaF, whereas the renal Na+/K(+)-ATPase in basolateral membranes showed a dip in activity 3 h after NaF treatment of the whole animal. Moreover, it was suggested from experiments with inhibitors of calphostin C and KT5720 that protein kinase C, but not protein kinase A, may play an important role in the suppression of Na+/K(+)-ATPase following the administration of fluoride to rats. Na+/glucose cotransporter was fairly insensitive to NaF, being competitively inhibited with a Ki of about 100 mM, whereas Na+/K(+)-ATPase was much more sensitive, with a Ki of about 2 mM. From these results, the elevation of urinary glucose excretion after a single dose of fluoride was deduced to be due to suppression of the renal Na+/K(+)-ATPase activity by a direct and/or secondary action of fluoride, rather than of the corresponding Na+/glucose cotransporter activity.

Animals↗
PubMed1995

Effects of bromocriptine on staining indices of Ki-67 and proliferating cell nuclear antigen, and nucleolar organizer region number in pituitary adenomas.

The effects of bromocriptine (CB-154) on the proliferative capacities of prolactinoma and somatotropinoma were investigated by immunocytochemical staining indices of proliferating cell nuclear antigen (PCNA) and Ki-67 (with MIB-1 antibody), and silver staining of nucleolar organizer region (NOR) number in histological sections. Patients with prolactinoma and somatotropinoma were divided into two groups: no preoperative treatment (control group), and treated with CB-154 for 2 weeks before adenomectomy (CB-154 group). The prolactinoma CB-154 group showed a significantly lower PCNA staining index (n = 6, 13.1 +/- 2.0%) and Ki-67 staining index (n = 6, 0.2 +/- 0.03%) than the control group (n = 4, 27.1 +/- 2.1%; n = 8, 1.9 +/- 0.5%; respectively) (p < 0.01). The somatotropinoma CB-154 group showed a significantly lower Ki-67 staining index (n = 5, 0.7 +/- 0.07%) than the control group (n = 11, 1.2 +/- 0.2%) (p < 0.05), but there was no significant difference in PCNA staining index (control: n = 5, 19.1 +/- 2.8% vs. CB-154: n = 5, 20.2 +/- 1.4%). However, variable intensities of PCNA staining between the cells were observed, resulting in an extraordinarily high staining index. NOR numbers did not vary significantly between the two prolactinoma groups (control: n = 4, 2.0 +/- 0.3 vs. CB-154: n = 6, 1.7 +/- 0.1) and two somatotropinoma groups (control: n = 5, 1.3 +/- 0.1 vs. CB-154: n = 5, 1.4 +/- 0.2).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Analgesia induced by transplantation of encapsulated tumor cells secreting beta-endorphin.

The purpose of this study was to assess whether xenogeneic tumor cells immunologically isolated in polymer capsules could survive and continue to reduce pain when transplanted into the cerebrospinal fluid (CSF) of rats. The mouse tumor cell lines AtT-20 and gene-transfected Neuro2A, which secrete beta-endorphin, were enclosed in polymer capsules at a density of 5 x 10(6) cells/ml and transplanted into the spinal CSF space of the occipitoatlantal junction in male Sprague-Dawley rats. The analgesiometric tests (tail pinch, hot plate, and electrical stimulation) showed that the five rats with encapsulated AtT-20 or Neuro2A (eight rats) were significantly less sensitive to pain after transplantation than the eight control animals (analysis of variance; p < 0.05). The analgesia induced by encapsulated cells secreting beta-endorphin could be attenuated by the opiate antagonist naloxone, which suggested the involvement of opiate in mediating this response. Morphological study revealed that the cells in polymer capsules survived 1 month after transplantation in the CSF space. In vitro experiments with cultured capsules showed that both encapsulated AtT-20 and Neuro2A secrete peptide for 1 month. The results of this study suggest that immunologically isolated xenogeneic tumor cells can secrete opiate in the CSF space, and this method may be applied to the treatment of cancer pain.

Analgesia↗
PubMed1995

[Clinical study on stage PT1 and grade 3 transitional cell carcinoma of the urinary bladder].

Thirty-three patients who had transitional cell carcinoma of the bladder with stage PT1 and grade 3 components were treated between January 1980 and December 1992. Clinical study was done for these 33 patients on treatment modalities and it's problem, intravesical recurrence, disease progression and prognosis. Twenty-five of 33 patients underwent bladder-sparing surgeries and total cystectomy was performed for another 8 patients as initial treatment. Intravesical recurrence was observed in 18 (72%) of 25 patients who underwent initial bladder-sparing surgeries. Recurrence-free rate was 44% for 1 year and mean period to recurrence from initial therapy was 13.1 months. Although some adjuvant therapy after initial treatment was performed for 20 patients, it's efficacy in preventing intravesical recurrence could not be confirmed. Disease progression was recognized in 10 (40%) of 25 patients initially treated by bladder-sparing surgeries after median latent period of 33.7 months, whereas only one (12.5%) of another 8 patients who underwent total cystectomy showed progression, and 5-year progression-free rate after initial bladder-sparing surgeries was 55.6%. Three and five-year actural survival rate in all cases were 81.5% and 65.1%, respectively. According to initial treatment, 5-year survival rate was 62.2% for the patients treated by bladder-sparing surgeries, whereas it was 83.3% for the cases who underwent total cystectomy. However statistical significant difference was not recognized. In view of disease progression after initial bladder-sparing surgeries, patients with progression yealed a 45.7% 5-year survival rate compared to 81.5% for the patients without progression, and significant difference was demonstrated between them.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Scintigraphic detection of xenografted renal tumor by anti-renal cancer monoclonal antibody radiolabeled with technetium-99m.

Accumulation in the tumor of the RCS-1 monoclonal antibody, which recognizes the cell surface antigen of renal cancer cells was examined. The antibody purified by affinity chromatography (protein-A column) and gel fractionation was labeled with technetium-99m (99mTc) by a direct method. High labeling efficiency (> 98%) could be routinely obtained. However, the 99mTc labeling of the antibody did not reduce the reactivity of the RCS-1 antibody. The labeled antibody was injected into nude mice transplanted with human renal and gastric tumors, and the accumulation of the antibody in each tumor and various tissues was compared at 48 hours after injection. The highest accumulation of radiolabeled RCS-1 antibody was observed in the AM-RC-3 renal tumors; at 8.0% of the injected dose per gram and a tumor-to-blood ratio of 1.05, respectively. However, the radiolabeled RCS-1, did not show specific accumulation in the gastric tumor nor in any tissues tested. The xenografted tumor, AM-RC-3 was successfully visualized with the radiolabeled RCS-1 antibody by scintigraphy.

Animals↗
PubMed1994

Structure of a novel phosphocholine-containing glycoglycerolipid from Mycoplasma fermentans.

Mycoplasma fermentans is thought to be a pathogen of rheumatoid arthritis or cofactor of AIDS. A novel phosphocholine-containing glycoglycerophospholipid named GGPL-I was isolated from a M. fermentans-infected human helper T-cell culture. It was revealed that GGPL-I is a lipid component of the M. fermentans and a major immunological determinant. The GGPL-I was purified by DEAE-Sephadex column chromatography and repeated Iatrobeads column chromatography. The purified glycophospholipid was subjected to structural characterization by thin-layer chromatography, Fourier-transform infrared spectrometry, liquid secondary ion mass spectrometry, and nuclear magnetic resonance spectroscopy. Its structure was determined to be as follows: 6'-O-phosphocholine-alpha-glucopyranosyl-(1'-3)-1,2-diacyl-sn-glycerol. This glycoglycerophospholipid is unique in containing phosphocholine, which is attached to C-6 of glucose. The stereospecific numbering (sn) of naturally occurring GGPL-I was determined through comparison with chemically synthesized compounds.

Carbohydrate Conformation↗
PubMed1994

Sphingosine inhibits the synthesis of RNA primers by primase in vitro.

We have previously shown the presence of sphingomyelin and sphingomyelinase in cell nuclei, suggesting that they may play a role in the intranuclear production of sphingosine, a potent bioactive molecule modulating diverse cellular functions. In the present study, the direct effects of sphingosine (C18:1) on the activity of DNA replication/repair polymerases were studied in vitro. Sphingosine had no effect on DNA polymerases alpha and beta and slightly inhibited DNA polymerases gamma, delta, and epsilon. In contrast, sphingosine strongly inhibited the activity of primase in a dose-dependent manner. On the other hand, dihydrosphingosine (C18:0), glycolipids, sphingomyelin, and ceramide had no effect on primase activity. Sphingosine equally inhibited the activity of primase complexed with DNA polymerase alpha, as well as its free form, with a Ki value of 4 microM. A gel-retardation analysis showed that the binding of primase with 32P-labeled template DNA was suppressed by sphingosine. Inhibition by sphingosine was competitive with the DNA template, but not with the substrate NTPs. After product analysis, a dose-dependent decrease in the amount of RNA primer products, consisting mainly of 10- and 11-mers, was observed in the presence of sphingosine, indicating that it inhibits the synthesis of RNA primers by primase. Sphingosine, however, had no effect on T7 RNA polymerase.

Animals↗