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T Taki

Publications and source records attributed to T Taki.

At least 199 records · Page 11Linked to original sources
PubMed1990

Accumulation of gangliosides with N-acetylneuraminosyl(alpha 2-6)lactosamine structure in primary human hepatoma.

Gangliosides of hepatomas have been analyzed by using a monoclonal antibody directed to N-acetylneuraminosyl(alpha 2-6)lactoneotetraosylceramide (sialyl(alpha 2-6)paragloboside), which was prepared by injecting the monosialoganglioside fraction of human meconium into BALB/c mice. The monoclonal antibody, named MSG-15, was found to bind sialyl(alpha 2-6)paragloboside, but it failed to react with other gangliosides, including N-acetylneuraminosyl(alpha 2-3)lactoneotetraosylceramide (sialyl (alpha 2-3)paragloboside) and "Ii"-type gangliosides. MSG-15 was found to recognize NeuAc alpha 2-6Gal beta structure of the ganglioside. Gangliosides obtained from human hepatomas were analyzed by immunostaining on high-performance thin-layer chromatography plates using the monoclonal antibody MSG-15. All primary hepatoma samples used in this study (nine samples) were found to contain sialyl(alpha 2-6)paragloboside, which accounted for 13-31% of the monosialoganglioside fractions in the hepatomas. Furthermore, MSG-15 recognized several monosialogangliosides in addition to sialyl(alpha 2-6)paragloboside. These gangliosides apparently also contain a terminal NeuAc alpha 2-6Gal beta structure. Other ganglioside fractions obtained from hepatoma and meconium were immunostained on thin layer chromatography plates with MSG-15. Additionally, another monoclonal antibody (H-11), which recognizes terminal lactosamine structure, was used to immunostain these fractions after sialidase treatment. Bands stained with both monoclonal antibodies showed similar mobilities to each other in the di- and trisialoganglioside fractions as well as monosialoganglioside fraction. In control liver, GM3 ganglioside accounted for 92% of monosialoganglioside fraction, and sialyl(alpha 2-6)paragloboside accounted for less than 1% of the fraction. Immunohistochemical study by using MSG-15 in tissue sections from hepatocellular carcinoma and normal liver tissues demonstrated that only hepatocellular carcinoma cells gave a positive reaction. These results suggest that the biosynthetic pathway of gangliosides containing NeuAc alpha 2-6Gal beta 1-4GlcNAc beta structure is activated in hepatoma cells.

Animals↗
PubMed1990

Anti-interleukin 2 receptor antibody attenuates low-dose streptozotocin-induced diabetes in mice.

Recent evidence indicates that activated T cells and macrophages play an important role in the induction of insulitis and diabetes in certain strains of mice treated with multiple subdiabetogenic doses of streptozotocin. In the present study, we treated C57BL/6J mice with five daily doses of 40 mg/ml streptozotocin and examined the prophylactic effect of an anti-interleukin 2 receptor monoclonal antibody (PC61). In mice treated with streptozotocin, interleukin 2 receptor-positive mononuclear cells were shown to infiltrate into the islets and soluble interleukin 2 receptors in the sera were significantly increased compared with control mice. The administration of PC61 to the mice attenuated the insulitis, and diminished interleukin 2 receptor-positive cells from islets and soluble interleukin 2 receptors in the sera. Moreover, the administration of PC61 significantly reduced the development of hyperglycaemia shown in these mice (12.8 +/- 1.1 mmol/l vs 18.5 +/- 0.7 mmol/l, p less than 0.005). As judged by flow cytometric analysis, this antibody did not cause any changes in either spleen cell counts or T cell subsets. Interleukin 2 receptors were expressed on a minor population of spleen cells regardless of treatment with PC61 (STZ + normal rat IgG: 2.1 +/- 0.3%, STZ + PC61: 2.4 +/- 0.3%). Even after stimulation of spleen cells with concanavalin A or alloantigen, interleukin 2 receptor expression was not significantly different between the two groups. Our studies suggest that interleukin 2 receptor-positive activated T cells or macrophages are important in the development of multi-low-dose streptozotocin diabetes and that an anti-interleukin 2 receptor antibody can attenuate this process.

Animals↗
PubMed1990

T98G glioma cells have nicks in DNA in quiescent phase.

Human glioblastoma-derived cell line, T98G, is arrested in the G1 phase of the cell cycle when serum is deprived. Using this cell line, we investigated the relation between the cell cycle and DNA single-stranded breaks, "nicks," by an in situ nick-translation method. When T98G cells were cultured without serum for 60 h, many small cells with condensed chromatin and scanty cytoplasm appeared. These small cells that were immunohistochemically considered to be in the G0 or early G1 phase had many nicks in DNA. When serum was added, these small cells with nicks disappeared within 1 to 4 h. VP-16, a DNA topoisomerase II inhibitor, delayed the disappearance of these small cells with nicks. This indicated that the action of DNA topoisomerase II on the chromatin is required to repair nicks in T98G glioma cells and to promote the progression from the quiescent to the proliferating phase.

Antigens, Surface↗
PubMed1990

Infantile osteopetrosis complicating neuronal ceroid lipofuscinosis.

An autopsy case of infantile osteopetrosis complicating neuronal ceroid-lipofuscinosis is reported. Autopsy revealed generalized sclerosis and thickening of cortical and spongy bones, formation of mineralized cartilagenous tissues, and narrowing of the marrow cavities associated with decreased hematopoietic cell components. Around the thickened bone trabecles, osteoclasts lacked a ruffled border and clear zone along the cell membrane facing the bone matrix surface. The brain was markedly atrophic with neuronal cell loss and focal gliosis, and the remaining neuronal cells accumulated brown granular pigments, which were confirmed histochemically and electron-microscopically to be ceroid and lipofuscin. In the cerebral medulla, the development of myelin sheaths was extremely poor. Also, the occurrence of Lex type glycolipids and GM3 and the apparent absence of cerebroside and cerebroside sulfate were proved by biochemical analysis, suggesting that the brain was still in a stage of embryonic development or still in the process of differentiation. Except for one suggestive case, this is the first case of complicating neuronal ceroid-lipofuscinosis in infantile osteopetrosis.

Atrophy↗
PubMed1990

Multiple intracerebral arteriovenous malformations in deep structure--case report.

The authors describe a case of multiple intracerebral arteriovenous malformations (AVMs) in a 23-year-old male with two distinct, deep-seated AVMs. One was located in the left basal ganglia, which had bled twice, and the other in the splenium. They were removed separately. He recovered satisfactorily with only a mild dysphasia. The authors emphasize that the therapeutic principle for multiple AVMs is the same as that for a solitary AVM. Multiplicity alone does not dictate the operability. Dissection just adjacent to the nidus and direct coagulation of an AVM are the indicated techniques, especially in cases of deep-seated AVMs in order to reduce postoperative neurological deficit.

Adult↗
PubMed1990

Motility factor produced by malignant glioma cells: role in tumor invasion.

To better understand the cellular mechanism of tumor invasion, the production of a cell motility-stimulating factor by malignant glioma cells was studied in vitro. Serum-free conditioned media from cultures of rat C6 and human T98G cell lines contained a factor that stimulated the locomotion of the producer cells. This factor was termed the "glioma-derived motility factor." The glioma-derived motility factor is a heat-labile protein with a molecular weight greater than 10 kD and has relative stability to acid. The factor showed not only chemotactic activity but also chemokinetic (stimulated random locomotion) activity in the two types of glioma cells studied. Although glioma-derived motility factors in conditioned media obtained from two different cell origins are likely to be the same, chemokinetic migration of T98G cells to their conditioned medium was much stronger than that of C6 cells to theirs. Coincubation of cells with cytochalasin B, which disrupts the assembly of cellular actin microfilaments, almost completely inhibited the cell migration stimulated by glioma-derived motility factor. Cytochalasin B also induced marked alterations in cell morphology, including cell retraction and arborization, while the drug did not affect cell attachment to culture dishes. These results indicate that glioma cells produce a motility factor which may play a role particularly when tumor cells are detached and migrate away from the original tumor mass, thus promoting tumor invasion. Also, glioma cell migration stimulated by the motility factor requires the normal organization of cytoskeletons such as actin microfilaments.

Animals↗
PubMed1990

A simple and specific assay of glycosyltransferase and glycosidase activities by an enzyme-linked immunosorbent assay method, and its application to assay of galactosyltransferase activity in sera from patients with cancer.

A simple, sensitive, and specific assay method for glycosyltransferase and glycosidase activities has been established by means of an enzyme-linked immunosorbent assay (ELISA) using monoclonal antibody, H-11 directed to lactoneotetraosylceramide (nLc4Cer). Enzyme activity was determined by assaying the amount of reaction product, nLc4Cer with the ELISA method. For the assay of galactosyltransferase activity, lactotriaosylceramide (Lc3Cer) immobilized on a 96-well microtiter plate was incubated with bovine milk galactosyltransferase in cacodylate buffer (pH 6.8) containing Triton CF-54, Mn2+, and UDP-galactose. Optimum incubation conditions for the enzyme were determined. Glycosidase activity was also assayed by the ELISA method by using Clostridium perfringens sialidase and neolacto-series gangliosides as substrates, and the substrate specificities towards the gangliosides were examined. By this method, 3-100 pmol of reaction product could be determined. The assay method has several advantages as follows: 1, the method is simple; 2, separation of the reaction product is not required; 3, quantification and identification of the reaction product were done simultaneously; 4, naturally occurring substrates are available (especially for glycosidase); 5, many samples can be assayed in one microplate; 6, sensitivity is very high. The present method was applied for the detection of galactosyltransferase in human sera. Significant elevations of the galactosyltransferase levels were observed in the sera from cancer patients. The formation of nLc4Cer was confirmed by employing the TLC-immunostaining method for bands of Lc3Cer after incubation of the bands with serum and cofactors on an HPTLC plate.

Antibodies, Monoclonal↗
PubMed1990

Glycolipid composition of a mutant cell line of mouse FM3A cells, and the effect of exogenous glycolipids on cell growth.

Had-1 isolated from mouse mammary tumour FM3A cells as a non-permissive cell line to Newcastle disease virus infection is deficient in NDV receptors, and galactosylation of the complex type sugar chains of the glycoproteins is extensively reduced compared to FM3A cells. It is also deficient in UDP-galactose transport into Golgi vesicles. The major neutral glycolipids in FM3A is Lac-Cer, whereas, in Had-1 cell, Glc-Cer is the major glycolipid and the concentration of neutral glycolipids is one-tenth as low as that in FM3A. GM3, GD3 and sialyl i- and I-type lactosaminylceramide are the gangliosides present in both FM3A and Had-1, although their presence in both cells is only in traces. Had-1 contains relatively high N-glycolyl-neuraminic acid. Among the several glycolipids tested, Lac-Cer, Gg-4-Cer and Glc-Cer showed inhibitory effect on proliferation of Had-1 cells, but did not show any appreciable effect on that of FM3A cells. Lac-Cer had the most potent inhibitory effect and this inhibitory effect was completely reversible. While mice injected with 5 x 10(6) cells of FM3A died in one month, those injected of Had-1 cells at the same dose survived for more than 6 months. Thus glycolipids on the cell surface play an essential role during cell growth both in vivo and in vitro.

Animals↗
PubMed1990

Factor VII deficiency first observed at preoperative routine clotting test.

Factor VII deficiency was first observed in a 24-year-old female in the routine clotting test for tooth extraction. Her factor VII was 22%, mildly below normal limits. Factor IX complex was not administered as replacement therapy when her impacted tooth was extracted. There was no sign of abnormal postoperative bleeding. As this disease was a rare disorder, the minimum safe level of factor VII for tooth extraction was unknown. We had a opportunity to study a patient with this disorder observed in the preoperative routine clotting test for tooth extractions.

Adult↗
PubMed1989

Epidermal growth factor receptor in human glioma.

Distribution of the epidermal growth factor (EGF) receptor in the surgical specimen of the human glioma was studied by immunohistochemical techniques using a monoclonal anti-EGF receptor antibody. Of 11 gliomas examined, EGF receptors were detected in nine glioblastomas and in one fibrillary astrocytoma. In the majority of cells, staining was observed over the cell membrane. Nuclear and cytoplasmic staining was also seen. In four glioblastomas, EGF receptor-positive cells were diffusely distributed in the tumor tissue. In one glioblastoma and one fibrillary astrocytoma, only a few positive cells were observed. These results imply the possible role of EGF receptors in the cellular proliferation of the human glioma.

Adolescent↗
PubMed1989

[In situ nick translation for detection of DNA damages in glioma cells].

DNA damaging agents such as nitrosoureas are widely used for the treatment of malignant gliomas. Therefore, quantitative measurement of DNA damages induced by antineoplastic drugs is useful to judge the efficacy of the drug and understand the pharmacological action of the drug. We have utilized in situ nick translation method to demonstrate "nicks" in DNA of glioma cells treated by various antineoplastic agents. Exponentially growing rat 9 L glioma cells (4 x 10(4] were seeded in the chamber slide. After fourty eight hours, the medium was changed to that containing various concentration of the drug (ACNU, cis-DDP, BLM, ADM and VP-16) and the cell was treated for 1 hour. Then, the cell was fixed for 10 minutes in methanol-acetic acid (v/v 3:1). Following fixation, the cell was incubated in the nick translation mixture containing E. coli DNA polymerase I, 3H-TTP, and 4 dNTP's (ATP, GTP, CTP, CTP and TTP) for 10 minutes at room temperature. The slide was dipped in the autoradiographic emulsion, exposed for 4 days at 4 degrees C, and then developed, the number of the silver grains over nuclei was counted under the microscope. For comparison of the effect of the drug to glioma cells, IC50 (inhibitory concentration of the drug for 50% cell kill) of each drug was determined by treating the cell for 48 hours at the various concentration of the drug. Small number of the silver grains was noted in cells with no treatment. Over IC50 as the concentration of the drug increased, the number of the nick increased in cells treated with bleomycin or adriamycin which are known to produce single strand breaks in DNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Gangliosides modulate Schwann cell proliferation and morphology.

We examined the effect of gangliosides on Schwann cell cultures isolated from neonatal rat sciatic nerves. Addition of gangliosides (GM1, GM3, and ganglioside mixture) at concentrations between 0.25 and 2 mg/ml significantly diminished both the baseline rate of proliferation of the Schwann cells and their response to two types of mitogens, the axolemmal fragments and derivatives of adenosine 3'-5'-monophosphate (cAMP). Gangliosides, the sialic acid residue of which had been removed, were highly toxic to the Schwann cells, which went to indicate that sialic acid is necessary to produce the inhibitory effects. Gangliosides also produced prominent changes in the morphological appearance of the Schwann cells. Most of the Schwann cells treated with gangliosides had an elongated shape with long processes and an alignment of end-to-end or side-by-side cell adhesion. These effects of gangliosides apparently were not mediated by cAMP, since intracellular cyclic adenosine monophosphate (cAMP) of Schwann cells at a basal- and forskolin-stimulated level was not altered by the exogenous gangliosides. These findings indicate that the direct effect of gangliosides on Schwann cells should also be considered as a background mechanism of ganglioside-induced facilitation of neuronal regeneration.

Animals↗
PubMed1988

Generation of two murine monoclonal antibodies that can discriminate N-glycolyl and N-acetyl neuraminic acid residues of GM2 gangliosides.

Since the preliminary analyses of the glycolipids of small cell carcinomas of the lung showed an increase of GM2 ganglioside, we generated new murine monoclonal antibodies directed to GM2 to identify the molecular species of the glycolipid. The monoclonal antibodies MK2-34 and MK1-16 (both IgM), which specifically detect N-glycolyl GM2 and N-acetyl GM2, respectively, were generated by immunizing mice with liposomes containing monophosphoryl lipid A, trehalose dimycolate, and the antigenic ganglioside. Among the glycolipid preparations extracted from the cancer tissues of 39 patients with lung cancer, a significant amount of N-acetyl GM2 was detected with MK1-16 antibody in 70% of the squamous cell carcinoma cases, 50% of the lung adenocarcinoma cases, 33% of the large cell carcinoma cases, and 100% of the cases of small cell carcinoma of the lung. On the other hand, N-glycolyl GM2 which was defined by the monoclonal MK2-34 was not found in any of the glycolipid fractions prepared from the lung cancer tissues examined in this study. Immunohistochemical studies of the lung cancer tissues with the MK1-16 antibody showed that the N-acetyl GM2 was present not only in small cell carcinoma tissues as one of the antigens related to tumors of neuroectodermal origin, but also in the squamous cell carcinoma and adenocarcinoma of the lung with a comparable frequency. The appearance of the N-acetyl GM2 antigen correlated well with the degree of differentiation of the cancer cells in patients with squamous cell carcinoma and adenocarcinoma of the lung.

Animals↗
PubMed1988

Detection of patients with cancer by monoclonal antibody directed to lactoneotetraosylceramide (paragloboside).

A hybridoma producing monoclonal antibody (H11) directed to lactoneotetraosylceramide (paragloboside) has been established from spleen cells of a mouse immunized with paragloboside. The monoclonal antibody H11 (immunoglobulin M type) was selected from five clones showing different reactivities with paragloboside. The monoclonal antibody was highly specific to paragloboside and lacked reactivity with other glycolipids including glucosylceramide, lactosylceramide, globotriaosylceramide, globotetraosylceramide, gangliotriaosylceramide, gangliotetraosylceramide, and GalNAc beta 1-4[NeuAc alpha 2-3]Gal beta 1-4Glc beta 1-1Cer. However, the monoclonal antibody (H11) was found to bind to lactosamine-containing glycolipids at their terminals, such as i- and I-type glycolipids as well as paragloboside. A two-step sandwich radioimmunoassay method for paragloboside antigen in serum was established by using the monoclonal antibody. The mean paragloboside antigen concentration in the sera from 20 normal individuals was 25.3 ng/ml. If the cutoff value was set at 80.9 ng/ml [25.3 + 2 x 27.8 (SD)], only 1 of 20 healthy controls had an elevated paragloboside value in the serum, whereas sera from 9 of 12 (75.0%) hepatoma, 4 of 10 (40%) pancreatic cancer, 16 of 40 (40.0%) stomach cancer, and 6 of 10 (60%) lung cancer patients had elevated paragloboside values. Sera from 3 of 8 hepatitis patients and 7 of 10 liver cirrhosis patients were estimated to be positive but sera from 16 patients with benign disease had paragloboside levels lower than the cutoff value. A larger amount of the antigen was found in liver metastases from colorectal carcinoma compared to the normal counterpart. The antigen was also detected in the medium of various human cancer cells and meconium. However, the antigen in the sera, medium, meconium, and cancer tissue seemed to be associated with glycoprotein or lipoprotein, because most of the antigen activity was eluted in the void volume fraction on high-performance liquid chromatography with a gel filtration column.

Antibodies, Monoclonal↗
PubMed1988

Lymphocyte subsets in human thymoma studied with monoclonal antibodies.

Lymphocyte subsets were investigated using OKT series monoclonal antibodies and flowcytometry in 16 cases of thymoma. From the viewpoint of lymphocyte subsets, thymoma could be divided into three types: thymus lymphocyte type, peripheral lymphocyte type, and intermediate type. In thymus lymphocyte type, the number of OKT-6+ cells exceed that of OKT-3+ cells, and are more than 50%. In peripheral lymphocyte type, the number of OKT-6+ cells are less than that of OKT-3+ cells and less than 10%. In intermediate type, OKT-6+ cells are between 10% and 30%. These three types correlate well with the histologic features with respect to the number and distribution of lymphocytes in thymoma tissue. Lymphocytes were infiltrating abundantly and intermingled in the tumor cell nests in thymus lymphocyte type, and were infiltrating rather scantly and outside the nests in peripheral lymphocyte type.

Adolescent↗
PubMed1988

Lactate dehydrogenase isoenzyme-1 in the mediastinal yolk sac tumor.

LDH isozymes in both the serum and tumor tissues of 4 patients with mediastinal yolk sac tumors, and in the cystic content of tumors transplanted into nude mice was examined. Our findings suggested that LDH-1, along with AFP, is an important marker of this tumor, and that LDH isozyme study is necessary for its diagnosis.

Adolescent↗
PubMed1988

Human placenta gangliosides.

Gangliosides extracted from human placenta were composed of four major components (G1-G4), which were purified by silica beads column chromatography. The structures of these gangliosides were analyzed by exoglycosidase treatments, 400 MHz proton magnetic resonance spectroscopy and gas chromatography-mass spectrometry and were concluded to be as follows: (Formula: see text). Gangliosides containing more than 10 sugar residues were observed in addition to the above four major components. But ganglio-series gangliosides were undetectable in the placenta.

Amino Sugars↗