Biomedical subjects

M Takeuchi

Publications and source records attributed to M Takeuchi.

At least 577 records · Page 32Linked to original sources

PubMed1994

[The effect of ocular and/or pineal body removal in mice with spontaneously developing uveoretinitis].

Autoimmune uveoretinitis and pinealitis have been shown to develop spontaneously in BALB/c nude mice after their T cell function has been reconstituted by embryonic F344 rat thymus grafting (TG nude mice). Because anti-IRBP antibodies were detected in these mice, it was concluded that IRBP was the target antigen. In this study, we removed the eyes and/or the pineal body from TG nude mice, and examined anti-IRBP antibodies in their sera. It appeared that IRBP originating from the eyes and the pineal body were the immunogenic antigens in the TG nude mice, but the IRBP from the eyes was found to be more immunogenic and pathogenic than that from the pineal body. We also found that the incidence of uveoretinitis increases with pinealectomy in TG nude mice, even though the immune system is not affected.

Animals↗

PubMed1993

Functional and physical interaction of protein-tyrosine kinases Fyn and Csk in the T-cell signaling system.

The Src-like protein-tyrosine kinase Fyn is associated with T-cell antigen receptor. Transient expression of actively mutated Fyn, having Phe-528 instead of Tyr-528 or Thr-338 instead of Ile-338, in Jurkat T-cells stimulated the serum response element (SRE), 12-O-tetradecanoyl-phorbol-13-acetate response element, cyclic AMP response element, and c-fos promoter. The stimulation of SRE was particularly prominent not only with active Fyn but also with normal (wild-type) Fyn. SRE was also stimulated by both normal and active Lck. Furthermore, normal and active Fyn stimulated transcription from the IL-2 gene promoter when transfected cells were stimulated by concanavalin A plus 12-O-tetradecanoylphorbol-13-acetate. Under the same conditions, Lck did not stimulate IL-2 promoter unless it was activated by mutation. Interestingly, a mutant Fyn, which has deletions within the SH2 region and so is able to transform chicken embryo fibroblasts, did not stimulate either the c-fos or IL-2 promoter, suggesting the importance of this region in T-cell signaling. Csk, which phosphorylates tyrosine residues in the negative regulatory sites of Src family kinases, down-regulated Fyn- and Lck-mediated stimulation of the serum response element and Fyn-mediated enhancement of IL-2 promoter activity. These data suggest that Fyn and Lck, whose activities are regulated by Csk, are involved in different phases of T-cell activation.

Amino Acid Sequence↗

PubMed1993

Cytokines affecting survival and differentiation of an astrocyte progenitor cell line.

The effects of various cytokines on survival and differentiation of an astrocyte progenitor cell line (AP-16) were examined. Epidermal growth factor (EGF) deprivation caused death of AP-16 cells by apoptosis. Transforming growth factor-alpha (TGF-alpha) and basic fibroblast growth factor (bFGF) prevented the apoptosis occurring in the absence of EGF. Leukemia inhibitory factor (LIF) and ciliary neurotrophic factor (CNTF) induced glial fibrillary acidic protein (GFAP) and decreased A2B5 antigen in AP-16 cells, indicating that these cytokines induced AP-16 cells to differentiate into astrocytes.

Animals↗

PubMed1993

High concentrations of immunoreactive gliostatin/platelet-derived endothelial cell growth factor in synovial fluid and serum of rheumatoid arthritis.

Since neovascularization plays an important role in the propagation of rheumatoid synovitis, we analyzed the concentration of gliostatin/platelet-derived endothelial cell growth factor (GLS/PD-ECGF), a potent angiogenic and chemotactic factor, in the synovial fluid and serum of rheumatoid arthritis (RA) patients. The immunoreactive GLS/PD-ECGF concentrations (mean value +/- S.D.) in synovial fluid, measured by a sandwich enzyme immunoassay, were significantly higher in RA patients than in osteoarthritis (OA) patients (233.02 +/- 219.40 vs. 9.09 +/- 14.86 ng/g, P < 0.001), and the serum concentrations were also higher in RA patients than in age-matched controls (8.77 +/- 7.60 vs. 3.74 +/- 2.61 ng/ml, P < 0.005). These results suggest that GLS/PD-ECGF may participate in the endothelial proliferation resulting in initiation of the extensive emigration of mononuclear cells and proliferation of the synovial tissues in rheumatoid arthritis, and that the immunoreactive GLS/PD-ECGF in serum as well as synovial fluids may be a useful diagnostic marker of RA.

Arthritis, Rheumatoid↗

PubMed1993

Establishment of an astrocyte progenitor cell line: induction of glial fibrillary acidic protein and fibronectin by transforming growth factor-beta 1.

An immortalized clonal cell line (AP-16) has been established from glial cultures obtained from neonatal mouse cerebra by multipassages under serum-free conditions. Immunofluorescent experiments showed that AP-16 cells expressed a marker for glial progenitors (A2B5) and did not express markers for oligodendrocytes (galactocerebroside) or mature astrocytes (glial fibrillary acidic protein: GFAP). Treatment with transforming growth factor-beta 1 (TGF-beta 1) or fetal calf serum (FCS) for 2 days induced AP-16 cells to differentiate into A2B5-negative, GFAP-positive, phenotypically mature astrocytes. AP-16 cells depended on epidermal growth factor for survival, and their growth was inhibited by FCS. These results indicate that AP-16 cells retained the properties of astrocyte progenitors. An enzyme-linked immunosorbent assay showed that AP-16 cells synthesized fibronectin and laminin, and that the expression of fibronectin was increased by TGF-beta 1. AP-16 cells should be useful for studying the roles of TGF-beta 1 in the differentiation of astrocyte progenitors.

Animals↗

PubMed1993

Establishment of an enzyme immunoassay system for gliostatin/platelet-derived endothelial cell growth factor (PD-ECGF).

A two-site enzyme immunoassay for gliostatin (GLS)/platelet-derived endothelial cell growth factor (PD-ECGF) has been developed. The detection limit of gliostatin/PD-ECGF was 30 pg/well, and the optimal assay range was 0.1 to ng/well. This assay system enabled us to confirm the immunochemical identity of both factors and to detect immunoreactive gliostatin/PD-ECGF (IR-GLS/PD-ECGF) in human biological body fluids. The age-related analysis from newborn to 69 years revealed that the serum IR-GLS/PD-ECGF level was high in infants younger than 1 year old (1.8 ng/ml) and in the 20-year-old age group (1.8 ng/ml), and highest in the umbilical cord blood (2.1 ng/ml). Curiously high concentrations were detected in saliva with a significant sex difference (11.3 ng/ml for males and 48.7 ng/ml for females), and in synovial fluids (3.7 ng/ml). A number of human tumor cells, gastric cancer cells, MKN-74, neuroblastoma cells, GOTO, as well as epidermoid carcinoma cells, A431, were found to produce a significant amount of IR-GLS/PD-ECGF (0.2 to 21.8 ng/mg protein), and some of them secreted the IR-GLS/PD-ECGF in the conditioned medium (approximately 0.5 ng/ml). The enzyme immunoassay system is sufficiently sensitive for the basic and clinical study of gliostatin/PD-ECGF in human body fluids, tissues and organs.

Adolescent↗

PubMed1993

Nucleotide sequence of the cDNA encoding mouse thyroid peroxidase.

The nucleotide (nt) sequence of the cDNA encoding mouse thyroid peroxidase (TPO) has been determined. The TPO cDNA is 3281 nt long and its open reading frame encodes a protein composed of 914 amino acids (aa), including a putative initiation Met. The mouse TPO cDNA shows 75.3, 70.8, and 93.5% homology in the coding nt sequence with human, porcine, and rat TPO cDNAs, respectively. In the aa sequence, mouse TPO shows 73.4, 68.4, and 93.9% homology with human, porcine, and rat TPOs, respectively. Specifically, the aa sequence surrounding the proximal His residue, probably essential for TPO activity, is well conserved among these four organisms.

Amino Acid Sequence↗

PubMed1993

Age-related changes of T cell subsets in intestinal intraepithelial lymphocytes of mice.

Age-related changes in T cell subsets were examined in intestinal intraepithelial lymphocytes (i-IEL), which contain unique T cells differentiating extrathymically. In 2-month-old mice bred under conventional condition, i-IEL consisted of a large number of CD4-CD8 alpha/alpha+ cells bearing either T cell receptor (TcR)alpha/beta or TcR gamma/delta and only a few CD4+CD8 alpha- cells. In aged mice (6 months old and 24 months old), unique CD4+CD8 alpha/alpha+ i-IEL bearing TcR alpha/beta increased in number and conversely the proportion of TcR gamma/delta+ i-IEL was decreased. Such an increase in number of CD4+CD8 alpha/alpha+ cells was detected in i-IEL from aged (14-months old) nude mice, but not in aged (14 months old) germ-free mice, suggesting that a significant fraction of TcR alpha/beta T cells such as CD4+CD8 alpha+ i-IEL can develop along an extrathymic pathway under the influence of intestinal microflora with age.

Age Factors↗

PubMed1993

Structures of mucin-type sugar chains on human erythropoietins purified from urine and the culture medium of recombinant Chinese hamster ovary cells.

Less is known about the mucin-type sugar chains attached to human erythropoietin as compared with N-linked sugar chains which structures and function have been well studied. In this study, we purified urinary human erythropoietin from three independent groups of aplastic anemia patients, and analyzed the structures of mucin-type sugar chains as well as that obtained from recombinant human erythropoietin produced by Chinese hamster ovary cells. Unlike the N-linked sugar chains, the mucin-type sugar chains are totally different between the urinary and the recombinant erythropoietins. All of the three independent samples of urinary erythropoietin contained oligosaccharides with the structures of +/- Neu5Ac alpha 2-->6GalNAc, while recombinant human erythropoietin contained those with the structures of Neu5Ac alpha 2-->3Gal beta 1-->3(Neu5Ac alpha 2-->6)GalNAc, Neu5Ac alpha 2-->3Gal beta 1-->3GalNAc, and Gal beta 1-->3(Neu5Ac alpha 2-->6)GalNAc.

Anemia, Aplastic↗

PubMed1993

A comparison of current expressions of nasal patency.

Rhinomanometry is well established as a useful clinical method for objective assessment of nasal patency, although several expressions of nasal patency have been reported and universal standardization has not been achieved. In this communication, nasal resistances were calculated from the equation R = delta P/V (R; resistance; delta P; transnasal differential pressure; V; nasal airflow) at delta P 100 Pa and at peak flow. Time-averaged nasal resistances and integrated nasal patencies were measured in 350 adult patients by Rhinorheograph MPR-1100 and processed by a NI-101 computer program. The values from the equation R = delta P/V at delta P 100 Pa were slightly lower than those from the same equation at peak flow or those from the time-averaging method. Correlations between the values of nasal resistance at peak flow and the time averaging method were very close to the line of identity. No significant correlations were demonstrated between integrated nasal patency and the values from the other three expressions. The differences of the results from these expression are discussed.

Adolescent↗

PubMed1993

Intrathecal injection of high-dose meglumine amidotrizoate with complete recovery.

Rarely we are faced with accidental spinal injection of potentially toxic substances. We present 2 cases in which amidetrizoate, water-soluble ionic contrast medium, was accidentally injected intrathecally. Our treatment consisted of vigorous hydration and barbiturate coma. This report suggests that for water-soluble ionic contrast media increasing cerebrospinal fluid circulation by vigorous hydration may be as effective as spinal lavage in diminishing toxicity.

Adult↗

PubMed1993

Development of acute myocardial infarction associated with coronary collateral regression after reperfusion by percutaneous transluminal coronary angioplasty.

Clinical and experimental observations have suggested that newly developed collaterals usually remain even after successful revascularization. We present a patient in whom coronary collateral regression was angiographically demonstrated within about 1 month after percutaneous transluminal coronary angioplasty, which led to the development of acute myocardial infarction. This case suggests that there may be a possibility of unexplained clinically important anatomical or functional regression of collaterals after reperfusion.

Adult↗

PubMed1993

Comparison of the effects on arterial-ventricular coupling between phosphodiesterase inhibitor and dobutamine in the diseases human heart.

OBJECTIVES: The aim of this study was to compare the effects of a phosphodiesterase inhibitor and catecholamine on arterial-ventricular coupling and myocardial energetics in the diseases human heart. BACKGROUND: Recent experimental studies have indicated that the arterial-ventricular coupling analysis using the time-varying elastance model could discriminate between inotropic and vasoactive effects of the two agents. METHODS: With the use of a conductance catheter, left ventricular contractility and arterial afterload were measured from the slope of the end-systolic pressure-volume relation, Emax, and the slope of the end-systolic pressure-stroke volume relation, Ea. Arterial-ventricular coupling was assessed by Ea/Emax before and after administration of a new phosphodiesterase inhibitor, E-1020 (0.3 microgram/kg per min), and a beta 1-stimulant, dobutamine (5 micrograms/kg per min), in 20 patients with heart disease. Left ventricular mechanical efficiency was assessed as the ratio of stroke work to myocardial oxygen consumption per beat measured by the thermodilution method. RESULTS: The slope of the end-systolic pressure-volume relation increased comparably with both E-1020 (39%, p < 0.01) and dobutamine (47%, p < 0.01), but Ea/Emax decreased with E-1020 (1.25 to 0.78, -37%, p < 0.01) more than with dobutamine (1.23 to 0.99, -16%, p < 0.05). Although stroke work index increased with both agents, myocardial oxygen consumption remained unchanged with E-1020 but increased with dobutamine (p < 0.05). Consequently, left ventricular mechanical efficiency increased with E-1020 (0.30 to 0.36, p < 0.05) but remained unchanged with dobutamine (0.27 to 0.29, p = NS). CONCLUSIONS: The phosphodiesterase inhibitor E-1020 improved arterial-ventricular coupling more than did dobutamine, with a resultant increase in mechanical efficiency. These data were in accordance with the theoretic prediction of the coupling analysis in the diseases human heart.

Arteries↗

PubMed1993

The diagnostic use of low molecular weight keratin expression in sebaceous carcinoma.

Sebaceous carcinoma is an infrequent skin tumor and its histological features sometimes closely resemble those of squamous cell carcinoma (SCC) and basal cell epithelioma (BCE), which often leads to a misdiagnosis. In the present immunohistochemical study, however, sebaceous carcinoma exhibited quite a different expression of keratins from SCC and BCE. We immunohistochemically examined 26 excised specimens of sebaceous carcinoma, 10 of SCC and 12 of BCE of the eyelids, using two monoclonal antibodies against high molecular weight keratins, 34 beta B4 (68kd) and 34 beta E12 (56kd, 56.5kd, 58kd), and two monoclonal antibodies against low molecular weight keratins, 35 beta H11 (54kd) and CAM5.2 (39kd, 43kd, 50kd). The cases of sebaceous carcinoma were positive with 34 beta B4 (23%), 34 beta E12 (54%), 35 beta H11 (81%) and CAM5.2 (73%). Of the four anti-keratin antibodies used in this study, 35 beta H11 was negative in all cases of SCC or BCE. These findings indicate that when sebaceous carcinoma is suspected, but no fat staining appropriate materials are available, a monoclonal antibody against low molecular weight keratin, 35 beta H11 (54kd), can be a useful tool to immunohistochemically rule out both SCC and BCE.

Adenocarcinoma, Sebaceous↗

PubMed1993

Immunocytochemical localization of copper-zinc superoxide dismutase in mouse olfactory mucosa.

Copper-zinc superoxide dismutase (Cu-Zn SOD) has been localized in mouse nasal mucosa. Immunocytochemical staining using polyclonal antibody against Cu-Zn SOD revealed endogenous Cu-Zn SOD in sustentacular cells in the olfactory area, and in ciliated epithelial cells in the respiratory area of the olfactory mucosa. Since these cells are located in the superficial portion of the olfactory mucosa, Cu-Zn SOD may serve as an intracellular antioxidant.

Animals↗

PubMed1993

A mitotic role for a novel fission yeast protein kinase dsk1 with cell cycle stage dependent phosphorylation and localization.

The fission yeast dsk1+ gene, a multicopy suppressor for cold-sensitive dis1 mutants, encodes a novel 61-kd protein kinase. It is a phosphoprotein, and phosphoserine is the major phosphorylated amino acid. Hyperphosphorylation of dsk1 causes a mobility shift, resulting in two dsk1-specific protein bands. The phosphorylation pattern is strikingly altered when cell cycle progression is delayed or arrested. The slowly migrating phosphorylated form is prominent in mitotically arrested cells, and the fast migrating form is enriched in interphase-arrested cells. dsk1 is a protein kinase. It auto-phosphorylates as well as phosphorylates myelin basic protein (MBP). Phosphotyrosine as well as phosphoserine/threonine were found in autophosphorylation, but no tyrosine phosphorylation occurs when MBP was used as the substrate. The dsk1 immunoprecipitates from mitotically arrested cells have a several-fold higher kinase activity than that from wild type. The haploid gene disruptant is viable, indicating that the dsk1+ gene is non-essential for viability. High dosage of dsk1+, however, strongly delays the G2/M progression. Immunofluorescence microscopy using anti-dsk1 antibody shows that localization pattern of dsk1 protein strikingly alters depending on cell cycle stages. In G2-arrested cells, dsk1 locates in the cytoplasm, whereas in mitotically arrested cells, nuclear stain is intense. In wild-type cells, nuclear stain is seen only in mitotic cells. Hence dsk1 protein may play an important role in mitotic control by altering cellular location, degree of phosphorylation and kinase activity. We discuss possible roles of dsk1 kinase as an add-on regulator in mitosis.

Amino Acid Sequence↗

PubMed1993

Proposal of six new species in the genus Aureobacterium and transfer of Flavobacterium esteraromaticum Omelianski to the genus Aureobacterium as Aureobacterium esteraromaticum comb. nov.

Twelve strains placed in the genera Flavobacterium, Pseudomonas, and Aureobacterium, including soil isolates, were characterized taxonomically. On the basis of morphological, physiological, and chemotaxonomic data, as well as DNA-DNA hybridization data, we propose that 11 of these strains should be classified in the genus Aureobacterium as new combinations or new species, as follows: Aureobacterium esteraromaticum comb. nov. (type strain, IFO 3751 [= ATCC 8091]), Aureobacterium arabinogalactanolyticum sp. nov. (type strain, IFO 14344), Aureobacterium keratanolyticum sp. nov. (type strain, IFO 13309), Aureobacterium luteolum sp. nov. (type strain, IFO 15074 [= DMS 20143]), Aureobacterium schleiferi sp. nov. (type strain, IFO 15075 [= DMS 20489]), Aureobacterium terrae sp. nov. (type strain, IFO 15300), and Aureobacterium trichothecenolyticum sp. nov. (type strain, IFO 15077 [= JCM 1358]). Whereas the peptidoglycan type of members of this genus is considered to be B2beta, the new species A. keratanolyticum was shown to have a new peptidoglycan type, murein variation B2alpha. An emended description of the genus Aureobacterium is presented.

Bacterial Typing Techniques↗

PubMed1993

Nephrotoxic serum nephritis in nude rats: the roles of host immune reactions in the accelerated type.

By immunization with rabbit immunoglobulins and the injection of a subnephritogenic dose of rabbit nephrotoxic serum (NTS), accelerated-type nephrotoxic serum nephritis (NTN) was induced in heterozygous (rnu/+) rats but not in athymic nude (rnu/rnu) rats. By transferring rat antibody against rabbit immunoglobulins, marked proteinuria was induced also in nude rats (202.0 +/- 98.4 mg/day on day 3) as in rnu/+ rats (122.6 +/- 35.3 mg/day on day 3). No marked differences in histological findings could be found between both groups. The most marked increase in the number of intraglomerular infiltrating cells was observed in heterozygous rats indicating that the presence of thymus-derived cells leads to the accumulation of more cells in glomeruli. We conclude that humoral immunity alone is enough to accelerate the pathogenic mechanism which induces glomerular injury with heavy proteinuria in this model.

Animals↗