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Biomedical subjects

T Endo

Publications and source records attributed to T Endo.

At least 703 records · Page 39Linked to original sources
PubMed1992

Heterogeneous responses of recombinant human thyrotropin receptor to immunoglobulins from patients with Graves' disease.

Non-thyroid mammalian cells, CHO-K1 cells, stably expressing human thyrotropin receptor (CHO-TSH-R cells) were used for the assay of thyroid stimulating antibody (TSAb) activities of IgGs from 24 patients with Graves' disease and we compared them with the values obtained in porcine thyroid cells. A significant positive correlation was observed between the results given by CHO-TSH-R cells (hTSAb) and porcine thyrocytes (pTSAb) (r = 0.94, p less than 0.001). However, we found that hTSAb values of IgGs from 5 patients were extremely different from their hTSAb values. Four out of these 5 IgGs showed strong pTSAb activity but exhibited a weak or negative hTSAb activity. Conversely, one out of 5 autoantibodies was very strong for hTSAb but its pTSAb was low. These heterogeneous responses of recombinant hTSH-R to Graves' IgGs suggest that there exist different types of TSAb and also that the epitope(s) for TSAb may be different from case to case.

Animals↗
PubMed1992

Regulation of endothelin-1 synthesis in cultured guinea pig airway epithelial cells by various cytokines.

To study regulatory mechanisms influencing the synthesis and release of ET-1, a potent bronchoconstrictor, epithelial cells from guinea pig tracheas were cultured to test various cytokines for the synthesis of ET-1 and its precursor, big ET-1. Cytokines tested were divided into 4 groups, based on their potential modes of action. IL-8, TNF alpha and TGF beta transiently increased the synthesis of ET-1, while EGF, PDGF and GM/CSF promoted proliferation of ET-1 synthesizing cells. IL-1 enhanced the synthesis of ET-1 precursor without mitogenesis, whereas IL-2, IL-6 and IGF-1 induced both the synthesis of big ET-1 and mitogenesis. These observations suggest that cytokines involved in damage, inflammation and repair of the airway epithelial layer regulate the synthesis and release of ET-1 by multiple mechanisms, thereby influencing airway muscle tone.

Animals↗
PubMed1992

The chloroplast-targeting domain of plastocyanin transit peptide can form a helical structure but does not have a high affinity for lipid bilayers.

Conformational properties and interactions with lipid membranes were studied for the chemically synthesized peptides PC(1-37) and PC(1-43), corresponding to the N-terminal 37 and 43 residues, respectively, of the transit peptide of the precursor to plastocyanin of Silene pratensis. PC(1-43) covers the entire chloroplast targeting domain of the transit peptide. CD spectra of PC(1-37) and PC(1-43) showed that both peptides have little ordered structure in aqueous solutions but form partially helical conformations in the presence of detergent micelles or in methanol. Vesicle disruption and direct-binding experiments revealed, however, that neither PC(1-37) nor PC(1-43) had a high affinity for lipid membranes. Since in the intact plastocyanin transit peptide the chloroplast-targeting domain is followed by a hydrophobic thylakoid-transfer domain, the plastocyanin precursor may well be transported to the chloroplast surface first with the aid of the thylakoid-transfer domain. The chloroplast-targeting domain may then form a helical structure in the lipid environments, and a chloroplast-specific motif displayed on the helical structure may be recognized by a receptor protein located at the chloroplast envelope membranes.

Amino Acid Sequence↗
PubMed1992

Nucleotide sequence of a cDNA encoding human tumor necrosis factor beta from B lymphoblastoid cell RPMI 1788.

Published sequences of cDNA for human tumor necrosis factor beta (TNF-beta) have a discrepancy within the coding region as well as exon 1. To resolve these discrepancies we have re-isolated TNF-beta cDNA from the human B cell lymphoblastoid cell line, RPMI 1788, and determined its DNA sequence. Results indicate that amino acid 26 is threonine (Thr) instead of asparagine (Asn). In contrast to published sequences, the sequence of the exon 1 region corresponded to the genomic sequence of TNF-beta. From our studies we conclude that the TNF-beta gene of the human B cell lymphoblastoid cell line, RPMI 1788, is homologous with respect to the TNF-beta gene.

B-Lymphocytes↗
PubMed1992

[Evaluation of transcatheter arterial embolization with coaxial microcatheter and micro-coil for vascular lesions].

Transcatheter arterial embolization using a coaxial microcatheter and micro-coil was performed in eight patients with vascular lesions; one each with aneurysm of the basilar artery, cerebellar artery, and pancreatic artery, pseudoaneurysm of the common hepatic artery, gastroduodenal artery, and gluteal artery, carotid-cavernous fistula, and thoracic paraspinal arteriovenous malformation. Complete occlusion was achieved in five patients with aneurysm and pseudoaneurysm by occluding the aneurysmal cavity and/or the orifice. A patient with recurrent carotid-cavernous fistula was also completely embolized. A case of basilar artery aneurysm resulted in partial occlusion because the posterior cerebral artery originated from the aneurysm. The unsatisfactory result in a case of paraspinal AVM was due to its wide extension with multiple feeding arteries. No apparent complication was seen. In conclusion, super-selective arterial embolization therapy with coaxial microcatheter and micro-coils was found to be a useful method for vascular lesions that would have been technically difficult to embolize with the standard catheter and coils.

Adult↗
PubMed1992

Immobilized lectin columns: useful tools for the fractionation and structural analysis of oligosaccharides.

Elucidation of the binding specificity of a concanavalin A-Sepharose column led to the possibility of the affinity chromatography of oligosaccharides and glycopeptides with the use of immobilized lectin columns. Subsequent addition of immobilized erythroagglutinating phytohaemagglutinin, Aleuria aurantia lectin, Datura stramonium agglutinin, Ricinus communis agglutinin and Allomyrina dichotoma agglutinin to the range of well characterized lectin columns has afforded a way to fractionate a mixture of N-linked oligosaccharides even to a single component.

Animals↗
PubMed1992

Carbohydrate binding specificity of immobilized Psathyrella velutina lectin.

The carbohydrate binding specificity of Psathyrella velutina lectin (PVL) was thoroughly investigated by analyzing the behavior of various complex-type oligosaccharides and human milk oligosaccharides on a PVL-Affi-Gel 10 column. Basically, the lectin interacts with the nonreducing terminal beta-N-acetylglucosamine residue, but does not show any affinity for the nonreducing terminal N-acetylgalactosamine or N-acetylneuraminic acid residue. Substitution of the terminal N-acetylglucosamine residues of oligosaccharides by galactose completely abolishes their affinity to the column. GlcNAc beta 1----3Gal beta 1----4sorbitol binds to the column, but GlcNAc beta 1----6Gal beta 1----4sorbitol is only retarded in the column. The behavior of degalactosylated N-linked oligosaccharides is quite interesting. Although all degalactosylated monoantennary sugar chain isomers are retarded in the column, those with the GlcNAc beta 1----2Man group interact more strongly with the column than those with the GlcNAc beta 1----4Man group or the GlcNAc beta 1----6Man group. The degalactosylated bi- and triantennary sugar chains bind to the column, but the tetraantennary ones are only retarded in the column. These results indicated that the binding affinity is not simply determined by the number of terminal N-acetylglucosamine residues. Addition of the bisecting N-acetylglucosamine residue reduces the affinity of oligosaccharides to the column, but addition of an alpha-fucosyl residue at the C-6 position of the proximal N-acetylglucosamine residue does not affect the behavior of oligosaccharides in the column. These results indicated that the binding specificity of PVL is quite different from those of other N-acetylglucosamine-binding lectins from higher plants, which interact preferentially with the GlcNAc beta 1----4 residue.

Basidiomycota↗
PubMed1992

Accuracy of the bronchoscopic DNA content analysis of non-small-cell lung carcinoma.

To assess the accuracy of the bronchoscopic DNA content analysis, samples of non-small-cell lung carcinomas (NSCLC) were investigated by means of flow cytometry. Samples were dissociated using the detergent Triton X-100. In 58 NSCLC cases, 39 (67%) had DNA aneuploid tumors. We compared the DNA indices of bronchoscopic brushing samples with 21 corresponding surgical samples. In 16 (76%) cases, DNA ploidy of both bronchoscopic and surgical samples were in concordance. In 3 (14%) cases, both bronchoscopic and surgical sample showed DNA aneuploidy, but the number of the DNA aneuploid stem cell lines was different. The cause of these differences was ascribed to the intratumor DNA heterogeneity. In 2 (10%) cases, the bronchoscopic sample showed DNA diploidy, but the surgical sample showed DNA aneuploidy. In these cases, tumor cells obtained by bronchoscopic brushing were so few that the small DNA aneuploid peak was undetectable in the DNA histogram. But the tumor DNA ploidy was evaluated correctly in 90% of 21 cases using bronchoscopic samples. Consequently, despite some drawbacks, the DNA ploidy diagnosis using bronchoscopic samples in this relatively small study, was almost as reliable as surgical samples.

Adenocarcinoma↗
PubMed1992

Management of patients with unresectable liver metastases from colorectal and gastric cancer employing an implantable port system.

Between 1985 and 1990, 50 patients with unresectable liver metastases from colorectal cancer and 34 subjects with metastases from gastric cancer were treated by repeated hepatic arterial infusion chemotherapy employing an implantable prot system. A catheter was inserted into the hepatic artery via the left subclavian artery and was connected to the implantable injection port in each patient. 5-Fluorouracil (5-FU) at 330 mg/m2 per week (167 mg/m2 daily given continuously over the initial 3 months for colorectal cancer), Adriamycin (ADR) at 20 mg/m2 every 4 weeks and mitomycin C (MMC) at 2.7 mg/m2 every 2 weeks were given to all 34 patients with gastric cancer and to 31 of the colorectal cancer patients. The remaining 19 patients with colorectal cancer received 5-FU at 1,000 mg/m2 every week. As a rule the treatment was performed on an outpatient basis. The side effects and complications observed included myelosuppression (23%), hepatic arterial occlusion (21%), and gastroduodenal mucositis (12%), although no major toxicity was encountered. The response rate (CR+PR) among the evaluated patients as determined using CT scans was 67% for colorectal cancer and 73% for gastric cancer. The overall median survival was 12 months and 15 months, respectively. Good local control of liver metastases from the colorectal and gastric cancers was achieved by repeated hepatic arterial infusion chemotherapy employing an implantable port system without the need for hospitalization and without producing major toxicity. Thus, the implantable port system is very useful for the management of patients with unresectable liver metastases.

Adult↗
PubMed1992

Restriction-fragment-length polymorphism and variation in electrophoretic karyotype in Naegleria fowleri from Japan.

Strains of Naegleria fowleri isolated in Japan from two different places were found to differ in electrophoretic karyotype and restriction-fragment-length polymorphism (RFLP) both from each other and from strains isolated on other continents. Using the Wagner parsimony method on the RFLP, we found that the Japanese isolates are most closely related to the Australian isolates and most distinct from the European isolates.

Animals↗
PubMed1992

Relation between the number of sperms to be deposited and pregnancy rate in tubal insemination in rabbits.

Pregnancy rate of tubal insemination with semen diluted to concentrations of x10(0) to x10(7) was studied in rabbits. The animals were laparotomized under general anesthesia, and 0.05 ml of diluted semen was injected with a glass capillary from the tubal fimbria into the oviduct. The semen was obtained from mature male rabbits by means of an artificial vagina and diluted to concentrations between x10(0) and x10(7). One hour after the insemination, ovulation was induced by administration of hCG. Six experimental groups were set up according to the semen concentrations. In the x10(0), x10(2), x10(4), and x10(7) groups, newborn rabbits were obtained. The best pregnancy rate was obtained with the x10(2) groups, in which 10(5) level of sperms were deposited. The newborn rabbits were normal not only morphologically, functionally, but also in chromosomal examination. The results suggested that tubal insemination with a small number of sperms could be applied in sterility due to oligospermia in human.

Animals↗
PubMed1992

Collaborative study using the preincubation Salmonella typhimurium mutation assay for airborne particulate matter in Japan. A trial to minimize interlaboratory variation.

A collaborative study has been performed over a period of 3 years to develop a suitable method for monitoring the mutagenicity of airborne particulate matter. The study was organized with 8 laboratories and performed in the following steps: (1) selection of a suitable technique for each process involved in the mutagenicity monitoring, (2) developing a tentative protocol by combining systematically the selected techniques, (3) evaluation of the protocol by intra- and inter-laboratory studies, (4) modification of the protocol according to the evaluation, and (5) evaluation of the modified protocol by conducting an interlaboratory study. We found a suitable method for mutagenicity monitoring of particles in the atmosphere. Airborne particles were sampled with a high-volume sampler, the samples were stored at -80 degrees C, extracted by sonication using dichloromethane, solvent-exchanged, and assayed by the preincubation method using Salmonella typhimurium TA98 and TA100. The observed mutagenic activity was normalized with that of an internal standard. Round robin tests revealed that the method resulted in excellent reproducibility. The coefficient of variation for mutagenic activities of airborne particulate samples collected in various districts of Japan were in the range of 14.7 +/- 6.6% to 19.6 +/- 4.0% for strains TA98 and TA100 with and without metabolic activation. We also found that the plate incorporation method was equivalent to the preincubation method for airborne particulate extracts.

Air Pollutants↗
PubMed1992

Vascular anatomy of the finger dorsum and a new idea for coverage of the finger pulp defect that restores sensation.

The cutaneous vascular anatomy of the finger dorsum was studied by dissection under loupe magnification of 71 fingers from 19 preserved cadaver hands. All specimens were injected with red latex or epoxy resin through a cannula in the brachial artery to identify the small vessels. The finger dorsum was supplied by the terminal branches from the dorsal metacarpal artery around the metacarpophalangeal joint. Other areas were nourished by the dorsal cutaneous branch from the proper palmar digital artery. There were two or three dorsal branches in the proximal phalangeal region and two in the middle phalangeal region. On the basis of these findings, we have developed a new method for one-stage reconstruction of finger pulp defect that restores sensation. Our innervated reverse vascular pedicle digital island flap includes the dorsal digital nerve and the proper palmar digital artery as a retrograde vascular pedicle. We have used the technique in three patients, with excellent results. The advantage of this procedure is that it provides a one-stage reconstruction of the pulp defect and restores sensation. The disadvantage is that the procedure requires neurorrhaphy.

Adult↗
PubMed1992

HIV-1 reverse transcriptase inhibitor from Phyllanthus niruri.

An aqueous extract of Phyllanthus niruri (Euphorbiaceae) inhibited human immunodeficiency virus type-1 reverse transcriptase (HIV-1-RT). The inhibitor against HIV-1-RT in this plant was purified by combination of three column chromatographies, Sephadex LH-20, cellulose, and reverse-phase high-performance liquid chromatography. The inhibitor was then identified by nuclear magnetic resonance (NMR) spectra as repandusinic acid A monosodium salt (RA) which was originally isolated from Mallotus repandus. The 50% inhibitory doses (ID50) of RA on HIV-1-RT and DNA polymerase alpha (from HeLa cells) were 0.05 microM and 0.6 microM, respectively, representing approximately a 10-fold more sensitivity of HIV-1-RT compared with DNA polymerase alpha. RA was shown to be a competitive inhibitor with respect to the template-primer while it was a noncompetitive inhibitor with respect to the substrate. RA as low as 10.1 microM inhibited HIV-1-induced cytopathogenicity in MT-4 cells. In addition, 4.5 microM of RA inhibited HIV-1-induced giant cell formation of SUP-T1 approximately 50%. RA (2.5 microM) inhibited up to 90% of HIV-1 specific p24 antigen production in a Clone H9 cell system.

Antigens, Viral↗
PubMed1992

Characterization of recombinant murine interleukin 5 expressed in Chinese hamster ovary cells.

We have purified recombinant murine interleukin 5 (rmIL-5) from the supernatant of Chinese hamster ovary cells. Each peptide fragment of the purified rmIL-5 generated by Achromobacter protease I digestion was characterized and glycosylation sites were determined. Although rmIL-5 contains three potential sites of N-linked glycosylation (Asn-26, Asn-55 and Asn-69), Asn-69 is not glycosylated. The oligosaccharides released from the protein by hydrazinolysis were fractionated by paper electrophoresis, lectin column chromatography and gel permeation chromatography, and their structures were analysed by sequential exoglycosidase digestion in combination with methylation analysis. The results indicated that they are a mixture of bi-, tri- and tetraantennary complex-type sugar chains with and without a fucose at the C-6 position of the proximal N-acetylglucosamine residue and high-mannose-type sugar chains. Although > 80% of the sugar chains are neutral oligosaccharides similar to recombinant human IL-5 (rhIL-5; Kodama, S., Endo, T., Tsuroka, N., Tsujimoto, M. and Kobata, A. (1991) J. Biochem., 110, 693-701), rmIL-5 has more tetraantennary oligosaccharides than rhIL-5. A site differential study revealed that Asn-55 has more tetraantennary oligosaccharides than Asn-26.

Amino Acid Sequence↗
PubMed1992

SV40 large T inhibits myogenic differentiation partially through inducing c-jun.

Terminal differentiation of skeletal muscle cells is obligatorily accompanied by the expression of a battery of muscle-specific genes and cell fusion to form multinucleated myotubes. The transcription of some of the muscle-specific genes is activated by the products of myoD gene family including MyoD and myogenin. The mouse skeletal muscle cell line C2SVTts11, which is a clone of C2 cells transfected with SV40 T antigen genes (temperature-sensitive large T and wild-type small t) fused to metallothionein gene promoter, is prevented from differentiation when the large T is induced. If the large T is induced in the myotubes, which are preformed in the absence of large T expression, the terminally differentiated cells reenter the cell cycle. In good accordance with the induction of large T, endogenous c-jun but not c-fos or c-myc mRNA was induced, whereas the expression of myoD and myogenin was suppressed. Treatment of quiescent C2 cells with a tumor promoter, 12-O-tetradecanoylphorbol 13-acetate, transiently induced c-jun and c-fos mRNAs, and temporarily deinduced myoD and myogenin mRNAs just after the expression of the protooncogenes. To ascertain whether c-jun induced by large T is sufficient to inhibit myogenic differentiation, c-jun cDNA was transfected into C2 cells. As the levels of exogenous c-jun expression were higher in the transfected clones, the cells expressed lower levels of myoD gene family and they formed fewer myotubes. Even the cells expressing the highest levels of exogenous c-jun, however, still formed small myotubes containing a few nuclei under differentiation conditions. These results suggest that large T inhibits myogenic differentiation by suppressing the expression of the members of myoD gene family, partly through inducing c-jun. In addition to this, other mechanisms seem to be required to achieve complete inhibition.

Animals↗
PubMed1992

Retinoblastoma gene product Rb accumulates during myogenic differentiation and is deinduced by the expression of SV40 large T antigen.

The cell growth suppression activity of the retinoblastoma gene (RB) product Rb is considered to be regulated by phosphorylation, whereas no positive correlation has been demonstrated between the activity and the amount of Rb protein in numbers of cell types examined. Both the RB mRNA and the protein were dramatically induced during terminal differentiation of the mouse skeletal muscle cell line C2 and its transfectant C2SVTts11, which stably harbors the SV40 T antigen gene linked to an inducible promoter. They were gradually deinduced when the terminally differentiated C2SVTs11 myotubes reentered the cell cycle through the induction of the large T antigen. Thus, the accumulation of Rb protein is likely to be required for growth arrest during differentiation of at least these myogenic cells, which have low basal levels of the protein.

Animals↗