Biomedical subjects

M Takeuchi

Publications and source records attributed to M Takeuchi.

At least 541 records · Page 30Linked to original sources

PubMed1994

Androgens directly stimulate mineralization and increase androgen receptors in human osteoblast-like osteosarcoma cells.

5 alpha-Dihydrotestosterone (DHT), an active form of testosterone, was shown to stimulate the mineralization of osteoblasts in a time- and dose-dependent manner in vitro in the presence of inorganic phosphate, as well as transforming growth factor beta and 1 alpha, 25 dihydroxyvitamin D3. However, DHT, stimulated the mineralization by a different mechanism from that of transforming growth factor beta and 1 alpha, 25 dihydroxyvitamin D3. We found that DHT increased the number of androgen receptors. These findings suggest that androgens directly stimulate mineralization in osteoblasts associated with an increase in the number of their receptors.

Alkaline Phosphatase↗

PubMed1994

Fission yeast cut3 and cut14, members of a ubiquitous protein family, are required for chromosome condensation and segregation in mitosis.

Fission yeast temperature-sensitive mutants cut3-477 and cut14-208 fail to condense chromosomes but small portions of the chromosomes can separate along the spindle during mitosis, producing phi-shaped chromosomes. Septation and cell division occur in the absence of normal nuclear division, causing the cut phenotype. Fluorescence in situ hybridization demonstrated that the contraction of the chromosome arm during mitosis was defective. Mutant chromosomes are apparently not rigid enough to be transported poleward by the spindle. Loss of the cut3 protein by gene disruption fails to maintain the nuclear chromatin architecture even in interphase. Both cut3 and cut14 proteins contain a putative nucleoside triphosphate (NTP)-binding domain and belong to the same ubiquitous protein family which includes the budding yeast Smc1 protein. The cut3 mutant was suppressed by an increase in the cut14+ gene dosage. The cut3 protein, having the highest similarity to the mouse protein, is localized in the nucleus throughout the cell cycle. Plasmids carrying the DNA topoisomerase I gene partly suppressed the temperature sensitive phenotype of cut3-477, suggesting that the cut3 protein might be involved in chromosome DNA topology.

Amino Acid Sequence↗

PubMed1994

Interactions of Escherichia coli endonuclease IV and exonuclease III with abasic sites in DNA.

Duplex oligodeoxynucleotides with synthetic analogs of abasic sites were used to study the specificity of the abasic endonucleases of Escherichia coli. The apparent Km values of exonuclease III for the tetrahydrofuranyl, propanyl, and deoxyribosyl substrates varied only somewhat (20-140 nM) in either Mg2+ or Ca2+ and were similar to those for endonuclease IV. In Mg2+, exonuclease III had a turnover number 4-13-fold higher than measured for endonuclease IV (ranging 5.6-18 min-1), but was lowered in Ca2+ to values similar to those for endonuclease IV. The rate of cleavage of tetrahydrofuranyl (F) substrate by both enzymes was unaffected by the base in the opposite strand or its replacement by a tetrahydrofuranyl moiety. A C:C mismatch on the 5' but not the 3' side of F strongly inhibited cleavage by exonuclease III in Ca2+, while mismatches on both sides were required to diminish endonuclease IV cleavage significantly. A phosphorothioate ester linked 5' to the tetrahydrofuranyl moiety inhibited both enzymes, with the Rp stereoisomer most effective. Endonuclease IV bound stably to duplex substrates containing the Rp phosphorothioate in the presence of poly(dI-dC). Although the apurinic/apyrimidinic-cleaving activities of endonuclease IV and exonuclease III have some common features they also differ in their specific interactions with DNA containing abasic sites.

Base Sequence↗

PubMed1994

Aberrant production of gliostatin/platelet-derived endothelial cell growth factor in rheumatoid synovium.

OBJECTIVE: To purify a protein inhibitor from rheumatoid arthritis (RA) synovial fluids which suppresses the apparent incorporation of 3H-thymidine into fibroblasts and synovial cells, and to define its biochemical features that have clinical relevance to the pathogenesis of RA. METHODS: Several standard chromatographic techniques were employed for the purification of the protein. Immunochemical methods with monoclonal antibody were used to quantify and visualize the protein in sera, synovial fluids, and tissues from RA patients. RESULTS: The chemical properties of purified inhibitor from RA synovial fluids confirmed its identity as gliostatin/platelet-derived endothelial cell growth factor (PD-ECGF), a potent angiogenic factor. The gliostatin/PD-ECGF level in synovial fluid and serum was higher in RA patients than in osteoarthritis controls. CONCLUSION: These findings strongly suggest that gliostatin/PD-ECGF might play an important role in the aberrant neovascularization of rheumatoid synovium.

3T3 Cells↗

PubMed1994

Delay in expression of a mammary tumor provirus is responsible for defective clonal deletion during postnatal period.

A gene-encoding ligand for deletion of T cells bearing TcRV beta 6 and V beta 8.1 cosegregates a new mammary tumor provirus locus, Mtv-50 in NC mice. The sequence of the open reading frame (ORF) in the 3' long terminal repeat (LTR) of Mtv-50 was strikingly similar to those of Mtv-7, Mtv-43 and exogenous mouse mammary tumor virus (SW) with properties of minor lymphocyte stimulating antigen 1a. Consistent with previous reports, clonal deletion of mature thymocytes bearing TcRV beta 6 was defective during the early postnatal period of mice carrying Mtv-50. Appreciable levels of mRNA corresponding to common Mtv ORF and Mtv-6 ORF were expressed in the neonatal thymus, while little, if any, mRNA corresponding to Mtv-50 ORF was detected in the thymus at the early postnatal stage. Delay in expression of Mtv-50 ORF during the postnatal period may be responsible for the failure of clonal deletion of V beta 6-T cells in the early postnatal life of mice carrying Mtv-50.

Amino Acid Sequence↗

PubMed1994

Granulomatous lesions in the lung induced by inhalation of mold spores.

The health hazards associated with grain dust exposure have been recognized as a cause of lung diseases. In the present study, we used germ-free rats exposed to Aspergillus versicolor to elucidate the mechanism for the lung damage induced by grain dust exposure. One month after exposure to the mold, remarkable proliferation of bronchus-associated lymphoid tissues with germinal centres was induced by aspiration of mold spores. After 1 month, alveolar macrophages increased, becoming foamy macrophages by ingestion and digestion of mold spores. They expressed interleukin (IL)-1, Ia antigens and intercellular adhesion molecule-1 intensely and occasionally bound lymphocytes. Numerous lymphocytes infiltrated the granulomatous lesions which consisted of accumulated foamy macrophages and some T lymphocytes which carried IL-2 receptor. Granulomatous lesions were identified in the entire lung, especially around bronchioles. They extended from alveolar ducts to alveolar spaces for 6 months after exposure to the mold. The macrophage appears to be a key effector cell in granulomatous reactions to inhaled molds.

Animals↗

PubMed1994

Extracorporeal urinary bypass for malignant ureteral obstruction.

Extracorporeal urinary bypass was attempted in a patient with malignant ureteral obstruction. A nephrostomy was drained into the bladder by connecting the tube to a cystostomy catheter. This method made the patient free from a collecting bag without any significant complications. This method may improve the quality of life of patients with malignant ureteral obstruction, when their bladder is intact.

Cystostomy↗

PubMed1994

Ultraviolet-B irradiation deforms the configuration of elastic fibers during the induction of actinic elastosis in rats.

We used scanning electron microscopy combined with perfusion fixation, resin injection and a selective digestion procedure to determine the effects of ultraviolet-B (UVB) radiation on the three-dimensional architecture of elastic fibers of rat skin. Chronic irradiation with a suberythematous dose of UVB (3 times/week for 12 weeks) produced a tortuous deformation of the superficial elastic fibers in the skin of the rat sole which normally are linearly arranged. Using computer analysis, we evaluated 40 individuals elastic fibers every 3 weeks for 12 weeks following the irradiation. This procedure confirmed the increasing tortuosity of the fibers, which was related to a decline in the elastic property of the skin in situ. Fine elastic branches developed among the deformed fibers and eventually anastomosed to produce an irregular network in the superficial dermal connective tissue, which may correspond to the development of actinic elastosis, that is, the UV-related accumulation of elastic fiber material.

Animals↗

PubMed1994

Role of prostaglandin E2 and prostacyclin in nonshivering thermogenesis during simulated birth in utero.

Prostaglandin E2 (PGE2) inhibits and prostacyclin (PGI2), stimulates lipolysis in vitro. Their role in initiating nonshivering thermogenesis at birth was investigated in 16 fetal sheep at 129-143 days gestation. In 10 fetuses indomethacin, a prostaglandin synthesis inhibitor, was infused; in 6 fetuses saline was administered as a control. 16 h later birth was simulated in utero. The plasma levels of PGE2 and PGI2 were unaffected by cooling. In the control fetuses, ventilation with oxygen caused PGE2 to fall, PGI2 to rise, and initiated moderate thermogenesis, signaled by a twofold increase in plasma free fatty acids (FFA). After umbilical cord occlusion, PGE2 decreased further (PGI2 was unchanged) and thermogenesis accelerated. In indomethacin-treated fetuses, in which the prostanoids had decreased and remained at approximately 20% normal, cooling initiated moderate nonshivering thermogenesis, and ventilation and cord occlusion caused no further changes. Changes in plasma adenosine were similar in control and indomethacin-treated groups. We conclude that declining PGE2 and rising PGI2 contribute to the initiation of thermogenesis at birth, but that other agents possibly of placental origin may play a contributory role.

6-Ketoprostaglandin F1 alpha↗

PubMed1994

The localization of lipopolysaccharide in an endotoxemic rat liver and its relation to sinusoidal thrombogenesis: light and electron microscopic studies.

The distribution of lipopolysaccharide (LPS) and sequential thrombus formation in the liver was investigated by immunohistochemical and cytochemical techniques in endotoxemic rats, using horseshoe crab factor C, a specific ligand for biologically active LPS, a monoclonal antibody against it, and rabbit anti-rat fibrinogen IgG. One hour after the intravenous administration of LPS (5 mg/kg), LPS was localized in the secondary lysosomes of Kupffer cells and in the vesicles of endothelial cells, mainly at the peripheries of the hepatic lobules. Small necrotic foci of hepatic tissue were scattered close to the LPS-containing Kupffer cells, and were frequently associated with infiltration of neutrophils and deposition of fibrin. Three hours after the administration of LPS, the immunohistochemical reaction of LPS became stronger and was mostly confined to Kupffer cells. Strands of polymerized fibrin were frequently observed on both the surface of the LPS-containing Kupffer cells and on endothelial cells. These findings suggest that the activation of the coagulation cascade in plasma is first initiated, even though only transiently, by hepatic necrosis which is probably caused by LPS-activated leukocytes, and then by the procoagulant activity expressed on the surface of both Kupffer cells and endothelial cells. Fibrinogen-related antigens were also immuno-ultrastructurally detected in the lysosomes of Kupffer cells three hours after the injection of LPS, which suggested that the Kupffer cells phagocytozed and degraded fibrin. Therefore Kupffer cells in endotoxemia may closely participate in both the sinusoidal thrombogenesis and degradation of fibrin.

Animals↗

PubMed1994

Effects of ryanodine on development of myogenic response in rat small skeletal muscle arteries.

OBJECTIVE: The aim was to elucidate the functional role of the sarcoplasmic reticulum in myogenic contraction. METHODS: Small arteries which perfuse the rat gracilis muscle were isolated and cannulated. The inner diameter was measured under no flow condition. Myogenic contraction was induced by increasing transmural pressure from 40 to 100 mm Hg. The diameter transient and the steady state internal diameter were analysed at 40 (ID40) and 100 mm Hg (ID100) of lumen pressure. RESULTS: In control, the vessels dilated immediately after the pressure change, and then constricted over approximately 4 min (the diameter decay). ID40 and ID100 were 120(SEM 16) and 108(12) microns (n = 6, p < 0.05), respectively. Ryanodine (10(-5) M) decreased ID40 to 82(8) microns. The relative rate of the diameter decay in the first 1 min was lower in the ryanodine treated vessels than in control, at 43(1)% v 74(7)%, n = 6 (p < 0.05). While KCl constriction was similar to that of ryanodine, the diameter decay was identical to that of control. Thus a decrease in baseline diameter was not of itself the cause of the depressed rate of diameter decay in the ryanodine treated vessels. Nisoldipine (10(-6) M) abolished myogenic contraction. CONCLUSIONS: Ryanodine sensitive sarcoplasmic reticular function is probably involved in the mechanism for developing the myogenic response in rat skeletal muscle small arteries.

Animals↗

PubMed1994

Depressed contractile state and increased myocardial consumption for non-mechanical work in patients with heart failure due to old myocardial infarction.

OBJECTIVE: The aim was to characterise the impaired myocardial mechanoenergetics in patients with heart failure due to old myocardial infarction by using the oxygen consumption versus left ventricular pressure--volume area (PVA) relationship. METHODS: The VO2-PVA relationship was assessed in 15 patients: group N consisted of seven patients with vasospastic angina pectoris whose left ventricular ejection fractions were normal [72 (SD 8)%], and group F consisted of eight patients with old myocardial infarction whose left ventricular ejection fractions were reduced [45(11)%]. Left ventricular volume and pressure were measured by the conductance catheter method. VO2 was measured by thermodilution. RESULTS: Linear VO2-PVA relationships with dextran infusions were obtained in both groups (median r = 0.92 v 0.90). There was no difference in the slope between the two groups. There was a positive correlation between Emax and VO2 at median PVA (VO2,PVA0.8) in group N. Emax, an index of left ventricular contractility, was significantly smaller in group F than in group N, at 5.1(2.1) v 3.2(1.1) mm Hg.ml-1.m2; p < 0.05). On the other hand, the VO2 intercept in group F was comparable to that in group N, at 0.71(0.63) v 0.40(0.29) J x beat-1.100 g LV-1; NS). In addition, the ratio of VO2,PVA0.8 to Emax was significantly larger in group F than in group N: 0.55(0.14) v 0.89(0.37) J x beat-1.100 g LV-1.mm Hg-1.ml.m-2 (p < 0.05). CONCLUSIONS: These results suggest that the VO2 for non-mechanical work in group F is disproportionately high relative to the reduced contractility. An abnormality of excitation-contraction coupling rather than of crossbridge cycling may be responsible for the impaired mechanoenergetics in patients with heart failure due to old myocardial infarction.

Adult↗

PubMed1994

Intercellular adhesion molecule-1 and leukocyte function-associated antigen-1 are involved in protection mediated by CD3+TCR alpha beta- T cells at the early stage after infection with Listeria monocytogenes in rats.

To investigate the significance of intercellular adhesion molecule-1 (ICAM-1) and leukocyte function-associated antigen-1 (LFA-1) in host defense against infection with intracellular parasites, we examined the effects of in vivo pretreatment with mAbs to ICAM-1 (1A29) and LFA-1 alpha (WT-1) on the protection against infection with Listeria monocytogenes in Fisher F344/N rats. Expression of ICAM-1 and LFA-1 alpha molecules on T cells in spleen, liver and peritoneal cavity of rats was down-regulated after i.p. administration with daily doses of 300 micrograms of either 1A29 or WT-1 for 10 days. The survival rate of rats inoculated with viable Listeria was significantly reduced by in vivo pretreatment with 1A29 together with WT-1 for 10 days but not by in vivo pretreatment with control mAb. The numbers of bacteria in the spleen in rats pretreated with both 1A29 and WT-1 were significantly increased on day 3 and day 6 after infection with 1 x 10(7) of viable Listeria corresponding to 1/30 of LD50 to normal rats. Thus, the resistance against listerial infection was severely impaired by combinational pretreatment with mAbs in ICAM-1 and LFA-1 alpha. As shown in our previous report, the early appearance of CD3+TCR alpha beta- T cells, presumably TCR gamma delta T cells, was evident in the peritoneal cavity and liver of control rats at the early stage after listerial infection, while this was suppressed at this stage in rats pretreated with both 1A29 and WT1.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Phylogenetic evidence for Sphingomonas and Rhizomonas as nonphotosynthetic members of the alpha-4 subclass of the Proteobacteria.

To clarify the taxonomic relationships of the genera Rhizomonas and Sphingomonas, the 16S rRNA sequence of Rhizomonas suberifaciens IFO 15211T (T = type strain) was determined. A phylogenetic analysis of aligned 16S rRNA gene sequences revealed that eight species of the genus Sphingomonas and R. suberifaciens are closely related to Erythrobacter longus and Porphyrobacter neustonensis and, therefore, belong in the alpha-4 subclass of the Proteobacteria. Within this subclass, Sphingomonas species and R. suberifaciens are phylogenetically interrelated and comprise several subgroups. Our findings show that the genus and species definitions of these organisms are in need of revision.

Bacteriochlorophylls↗

PubMed1994

Luteococcus japonicus gen. nov., sp. nov., a new gram-positive coccus with LL-diaminopimelic acid in the cell wall.

A new gram-positive, nonmotile coccus is described. Strains IFO 12422T (T = type strain) and IFO 15385 in the Institute for Fermentation, Osaka, culture collection, which were isolated from soil and water, respectively, have the following chemotaxonomic characteristics: menaquinone MK-9(H4); G + C content of DNA of 67 mol%; and LL-diaminopimelic acid, alanine, glycine, and glutamic acid in a molar ratio of ca. 1:2:1:1 (type A3 gamma). Mycolic acids are not present. The taxonomic characteristics of these organisms are different from those of previously described gram-positive, high-G + C-content cocci. The partial 16S rRNA sequence indicated that IFO 12422T represents a distinct line of descent among gram-positive bacteria with a high G + C content. The name Luteococcus japonicus gen. nov., sp. nov. is proposed. The type strain is strain IFO 12422.

Base Composition↗

PubMed1994

Transfer of Propionibacterium innocuum Pitcher and Collins 1991 to Propioniferax gen. nov. as Propioniferax innocua comb. nov.

16S ribosomal DNA analysis indicates that Propionibacterium innocuum is a phylogenetic neighbor of Luteococcus japonicus and that this pair of organisms branches intermediately between the genus Propionibacterium on the one side and the genera Aeromicrobium and Nocardioides on the other side. Phenotypically, strains of P. innocuum differ from species of Propionibacterium by exhibiting aerobic growth and possessing arabinose in the cell wall, they differ from species of Aeromicrobium and Nocardioides by the formation of propionic acid, and they differ from species of Luteococcus in morphology. Consequently, P. innocuum should not be classified with authentic Propionibacterium species, and the transfer of P. innocuum Pitcher and Collins 1991 to a new genus, Propioniferax, as Propioniferax innocua gen. nov., comb. nov. is proposed.

DNA, Bacterial↗

PubMed1994

Hyperthermic isolated limb perfusion with intra-arterial administration of carboplatin and/or interferon-beta for the treatment of malignant melanoma of the leg.

Our experiences of hyperthermic isolated limb perfusion with administration of carboplatin, interferon-beta or a combination of both are reported. Administration of high doses of these reagents was well tolerated by patients with melanoma without severe complications after the treatment. A total of 8 patients underwent this therapeutic modality. Remarkable clinical improvement was seen in the first patient, who was in Stage III at the time of the perfusion. Histopathological findings indicated severe damage to the melanoma cells after the operation. Prophylactic hyperthermic perfusion was performed in 6 other patients with Stage II-III melanoma of the lower limb. None of them have shown any signs of recurrence 1-10 months later. The activities of natural killer cells or T lymphocytes appeared to be increased when the perfusion was carried out with concomitant administration of both carboplatin and interferon-beta. These results suggest that hyperthermic isolated limb perfusion with carboplatin and/or interferon beta administration is effective in patients with advanced stage melanoma.

Adult↗

PubMed1994

Presence of p53 mutations in 3Y1-B clone 1-6: a rat cell line widely used as a normal immortalized fibroblast.

The 3Y1 cell line, established from a rat whole embryo, is widely used as a normal immortalized fibroblast. We analyzed p53 mutations in four clonal lines derived from the 3Y1 cell line; 3Y1-B clone 1-6, 3Y1-C and two clonal lines (3Y1 cl-3 and 3Y1 cl-6) which had been transformed by the human papilloma virus E6 gene. Polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis and DNA sequencing showed that three clonal lines had a double mutation at codons 130 and 136 on the same allele and that the other clonal line, 3Y1 cl-3, had no mutations. 3Y1-B clone 1-6, which has been registered as the standard clonal line at the Japanese Cancer Research Resources Bank, demonstrated weak bands of the wild type allele, suggesting the existence of heterogeneous cell types in this "clonal" line. PCR-SSCP analysis of 25 subclones obtained by limiting dilution of 3Y1-B clone 1-6 cells revealed a mixture of two types of cells; 12 subclones showed only the bands of mutated allele, and 13 subclones showed both bands of the wild and mutated p53 alleles. These findings should be taken into consideration when using this cell line as a normal immortalized cell line.

Animals↗