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Biomedical subjects

S Amano

Publications and source records attributed to S Amano.

At least 181 records · Page 10Linked to original sources
PubMed1990

5'-Nucleotidase activities in sera and liver tissues of viral hepatitis patients.

In order to disclose the mechanisms involving the elevation of serum 5'-nucleotidase (5'-N) activity in viral hepatitis patients, 5'-N activities in sera and liver tissues were examined in acute and chronic hepatitis patients and compared with normal controls. Serum 5'-N activities were 0.714 +/- 0.106 nanomoles adenosine/hour/mg protein in normal individuals, 1.162 +/- 0.479 in acute hepatitis patients, and 0.845 +/- 0.530 in chronic hepatitis patients. Tissue 5'-N activities were 298.8 +/- 86.7 in normal individuals, 598.1 +/- 198.3 in acute hepatitis patients, and 462.2 +/- 91.3 in chronic hepatitis patients. Serum 5'-N activity increased significantly in acute hepatitis patients, but not in chronic hepatitis patients. Tissue 5'-N activity increased in both acute and chronic hepatitis patients. The elevation of 5'-N activity in liver tissue was not an essential factor in the elevation of serum 5'-N levels. Other factors causing the release of 5'-N from liver tissue into the blood stream are thought to be more important. It is suggested that the shedding of plasma membrane with ecto 5'-N activity due to cell damage, or leakage of bile containing high 5'-N activity were causative factors.

5'-Nucleotidase↗
PubMed1990

A taxonomic review of the genus Microbispora and a proposal to transfer two species to the genus Actinomadura and to combine ten species into Microbispora rosea.

We conducted a taxonomic review of the genus Microbispora using chemotaxonomic and DNA-DNA hybridization techniques, and reached the following conclusions: Microbispora viridis should be transferred to the genus Actinomadura as Actinomadura rugatobispora comb. nov., nom. nov. (type strain SF2240 = IFO 14382 = JCM 3366) and Microbispora echinospora should be transferred to the genus Actinomadura as Actinomadura echinospora comb. nov. (type strain JCM 3148 = ATCC 27300). We also propose that Microbispora rosea, Microbispora amethystogenes, Microbispora chromogenes, Microbispora diastatica, Microbispora indica, Microbispora karnatakensis and Microbispora parva should be combined into the species Microbispora rosea subsp. rosea (type strain JCM 3006 = ATCC 12950), and that Microbispora aerata, Microbispora thermodiastatica and Microbispora thermorosea should be combined and transferred to the new subspecies Microbispora rosea subsp. aerata comb. nov. (type strain IFO 12581 = ATCC 15448). Microbispora bispora clearly differs from these ten strains at the species level.

Actinomycetales↗
PubMed1990

Monoclonal antibody against a serotype antigen of Porphyromonas (Bacteroides) endodontalis and characteristics of the antigen.

Recent studies have demonstrated the presence of three serotypes (O1K1, O1K2, and O1K-) of Porphyromonas (Bacteroides) endodontalis. In the present study, a hybridoma cell line producing monoclonal antibody (BEE11) specific for serotype O1K1 of P. endodontalis was established. The specificity of the antibody was evaluated by enzyme-linked immunosorbent assay and immunoslot blot analysis. BEE11 antibody reacted with strains ATCC 35406, HG 400, and HG 421 of the bacterium. However, it did not react with HG 422 or HG 948. Also, the antibody did not react with any of the black-pigmented Bacteroides strains tested. Although the antibody reacted with total cell envelope and capsule materials, it did not do so with lipopolysaccharide. The antibody reacted with antigen material having a molecular mass of 110 kilodaltons (kDa), as judged from fractionation by Superose 12 prep gel chromatography. When the peak fraction from the Superose 12 column was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot (immunoblot) analysis, the reactivity was detected as a single band at an apparent molecular mass of about 52 kDa. The antigen material purified partially by high-performance liquid chromatography was sensitive to trypsin, V8 protease, and heating to 80 degrees C but not to neuraminidase. Therefore, the present study shows that BEE11 antibody recognizes a serotype antigen of P. endodontalis which may be a dimer consisting of monomers having molecular masses of approximately 52 kDa and sensitivity to proteases and heat.

Animals↗
PubMed1990

Application of monoclonal antibodies to the detection of black-pigmented Bacteroides spp. in subgingival plaques by immunoslot blot assay.

The aim of the present study was to assess the application of monoclonal antibodies to the detection of black-pigmented Bacteroides spp. in subgingival plaques by immunoslot blot assay. Subgingival plaque samples from adult periodontal patients were examined by immunoslot blot assay with monoclonal antibodies that specifically recognize Bacteroides gingivalis, Bacteroides intermedius serogroups I and II, and Bacteroides melaninogenicus. The assay can detect specifically these Bacteroides spp. in the subgingival plaques. Therefore, we investigated the distribution of these Bacteroides spp. in the subgingival plaques of patients classified by Russell's periodontal index. Reactivities of their plaques with monoclonal antibodies toward B. gingivalis and B. intermedius serogroup I were clearly related to the severity of the periodontal disease, but this was not the case with B. intermedius serogroup II and B. melaninogenicus. These results indicate that this immunoslot blot assay using monoclonal antibodies toward these Bacteroides spp. provides simple detection and monitoring of these organisms in periodontal patients.

Adult↗
PubMed1989

An Epstein-Barr virus-transformed B cell line produces autoregulatory interleukin-1 that regulates bone remodeling.

In this study, we demonstrate that an Epstein-Barr virus-transformed B cell line, A-11, produced interleukin-1 (IL-1), a cytokine that regulates bone remodeling. A-11 cells produce IL-1 in a cell dose- and culture time-related manner. The IL-1 activity was neutralized by recombinant human IL-1 (rhIL-1) alpha antiserum, but not by rhIL-1 beta antiserum. The IL-1 was semi-purified by (NH4)2SO4 precipitation, Superose prep 12 gel filtration, and anion-exchange chromatography strongly stimulated in vitro bone resorption. The stimulatory effect of the purified IL-1 on bone resorption was prostaglandin independent. Purified IL-1 inhibited DNA and collagen synthesis in the osteoblastic cell line MC3T3-E1. However, it enhanced significantly the cellular activity of alkaline phosphatase (EC 3.1.3.1), a marker enzyme for differentiation of osteoblasts. On the other hand, A-11 cell proliferation was inhibited by addition of rhIL-1 alpha antiserum, but not by rhIL-1 beta antiserum. And cell proliferation was stimulated by exogenous rhIL-1 alpha and -beta.

Alkaline Phosphatase↗
PubMed1989

Anorectal motility in children with complete rectal prolapse.

Anorectal manometry, defecography, and ultrasonographic study were performed in 36 children with complete rectal prolapse and 45 age- and sex-matched controls. Anorectal manometry disclosed that there was no significant difference in Pr, Pac, or length of HPZ between patients and controls. The rate of BRC of the smooth muscle of the anal canal and RC were significantly lower in patients. Rectoanal reflex was present in all patients and controls. Defecography and ultrasonographic examination confirmed the hypothesis that rectal prolapse starts initially as an intussusception of the rectum, then fully develops. In 29 cases patients were cured by conservative treatment, but seven patients required surgical treatment. Results of modified Sudeck's operation were, in general, satisfactory.

Adolescent↗
PubMed1989

The occurrence of different types of spinal tumours in one patient. A case report and review of the literature.

Three histologically different types of spinal tumours were found in a 16-year old girl. Each tumour was detected independently at a distant region. They were two intramedullary ependymomas at C3 and T2, two schwannomas at the C6 and C7 root, and one intradural meningioma at T7. All tumours were successfully removed by a two-stage operation without adding neurological deficits. In this paper the findings of metrizamide myelography, metrizamide CT, intravenous enhanced CT and MRI are presented. The application of these various neuroradiological methods made it possible to confirm the precise location and the nature of the tumour in order to operate safely.

Adolescent↗
PubMed1989

Primary intracranial epidermoid carcinoma--case report.

A 38-year-old male who presented with trigeminal nerve paresis was found to have a cerebellopontine angle tumor. The tumor was subtotally removed. Multiple histological sections showed no malignant changes, and the diagnosis was typical epidermoid cyst. Tumor growth recurred twice and the diagnosis after the third operation was epidermoid carcinoma. A review of the available literature yielded only 22 reported cases of malignant intracranial epidermoid cyst.

Adult↗
PubMed1989

Recombinant interferon-gamma is a potent inhibitor of osteoblastic cell functions.

Interleukin-1 and tumor necrosis factor-stimulated bone resorption is mediated by osteoclast-activating factor elaborated by osteoblasts. Recombinant interferon-gamma inhibits stimulation of bone resorption by these cytokines. We examined here the effects of recombinant mouse interferon-gamma (rmIFN-G) on DNA and collagen synthesis, and on alkaline phosphatase (ALP) activity, in the osteoblastic cell line (MC3T3-E1) under confluent culture conditions. Addition of rmIFN-G to the cells markedly inhibited their DNA synthesis and ALP activity in dose- and culture time-related manner. Also we found that rmIFN-G decreased markedly collagen synthesis at day 3 after addition of the agent. These data indicate that rmIFN-G is a potent inhibitor of osteoblastic cell functions.

Alkaline Phosphatase↗
PubMed1988

Effects of recombinant human interleukin 1 alpha and interleukin 1 beta on cell growth and alkaline phosphatase of the mouse osteoblastic cell line MC3T3-E1.

Recombinant human interleukin 1 (rhIL-1)alpha and rhIL-1 beta were examined for their effects on DNA synthesis, cell growth and alkaline phosphatase activity of the mouse osteoblastic cell line MC3T3-E1. The relative activity of rhIL-1 alpha and rhIL-1 beta was compared in terms of the units which induced half-maximal [3H]thymidine uptake into mouse thymocyte cultures exposed to IL-1. Both rhIL-1 alpha and rhIL-1 beta significantly inhibited DNA synthesis and division of the cells in a concentration- and cultivation time-dependent fashion. In contrast, rhIL-1 alpha and rhIL-1 beta markedly increased alkaline phosphatase activity, which is a marker of osteoblastic differentiation. This activity in cells treated with rhIL-1 alpha and rhIL-1 beta increased about 2.0- and 1.7-fold, respectively, compared with that of control cultures. Inhibition of the DNA synthesis and stimulation of alkaline phosphatase activity by both types of rhIL-1 were completely neutralized by treatment with their respective polyclonal antisera. Also, inhibition of DNA synthesis was unaffected by the addition of cyclooxygenase and lipoxygenase inhibitors, and stimulation of alkaline phosphatase activity was unaffected by the addition of indomethacin. These results indicate that both rhIL-1 alpha and rhIL-1 beta have qualitatively similar biological effects on osteoblastic cells. They also suggest that IL-1 is an important modulator of the growth and differentiation of osteoblasts.

Alkaline Phosphatase↗
PubMed1988

Inductive effect of recombinant human interleukin-1 alpha and beta on differentiation of macrophage-like tumor cell line P388D1.

We used the mouse monocyte/macrophage-like tumor cell line P388D1 to test whether or not interleukin-1 (IL-1) stimulates differentiation of monocyte/macrophage progenitors. Incubation of these cells with recombinant human interleukin-1 (rhIL-1) alpha and beta resulted in their increased adherence, stimulation of nonspecific esterase activity, and increased Fc rosette formation. rhIL-1s inhibited cell growth and stimulated Fc rosette formation in a dose-dependent fashion. The cell growth inhibition due to rhIL-1s depended on the concentration of serum in culture medium. Synergism between rhIL-1 and calcium ionophore A23187 was found for the cell growth inhibition and Fc rosette formation. The presence of ethylene glycol bis- (beta-aminoethyl ether) N,N,N,N,-tetraacetic acid(EGTA) in the medium abolished the stimulatory effect of rhIL-1 on Fc rosette formation of the cell line. These results demonstrate that rhIL-1s are a potent inducer of the differentiation of the macrophage-like tumor cell line P388D1.

Animals↗
PubMed1988

Stimulatory effect on bone resorption of interleukin-1-like cytokine produced by an osteoblast-rich population of mouse calvarial cells.

We reported previously that an osteoblast-rich population of mouse calvarial cells treated with lipopolysaccharide produced on interleukin-1 (IL-1)-like cytokine that closely resembles IL-1. In the present study, we examined whether or not the IL-1-like cytokine stimulates bone resorption. As a result we found that the cytokine stimulate bone resorption significantly, and the stimulatory effect was dependent on cytokine dose and length of culture time. The stimulation of bone resorption and IL-1-like cytokine activity appear to be in parallel. Since the stimulatory effect of the cytokine was not abolished in the presence of indomethacin, the cytokine may stimulate bone resorption in a prostaglandin metabolite-independent manner. These results suggest the possibility that the IL-1-like cytokine may be involved as an autoregulatory factor in the bone-remodeling system.

Animals↗
PubMed1988

Lysosomal enzyme activities in the cerebral microvessels in spontaneously and renal hypertensive rats.

In an attempt to clarify the role of lysosomal enzymes in the developmental mechanisms of the changes of cerebral microvessels under hypertensive conditions, the activities of acid phosphatase, N-acetyl-beta-glucosaminidase, and beta-glucuronidase in the isolated microvessels from the cerebral cortex of spontaneously and renal hypertensive rats were biochemically studied. The activities of all the enzymes were higher than those in normotensive control animals, although there was a variation in intensity according to the age and kind of enzymes. The enzyme activities in spontaneously hypertensive rats showed a tendency to increase with advancing age. Hypertension seems to increase activities of lysosomal enzymes in cerebral microvessels, and this activation may in turn play a role in the development of further hypertensive cerebrovascular and cerebral changes.

Acetylglucosaminidase↗
PubMed1988

Effect of hypertension on lysosomal enzyme activities in aortic endothelial cells.

In order to obtain information about the changes in lysosomal enzyme activities in arterial endothelial cells under hypertensive conditions, a biochemical study was performed on 5 lysosomal enzymes, acid phosphatase, N-acetyl-beta-glucosaminidase (NAGase), cathepsin B, cathepsin D and beta-glucuronidase, in endothelial cells isolated by an enzymatic technique from the aorta of spontaneously and renal hypertensive rats, and normotensive control rats. The aortic endothelial cells in the old spontaneously and the renal hypertensive rats showed increased activities of enzymes examined in comparison with those in the age-matched control rats. Endothelial cells in young spontaneously hypertensive rats did not show any elevated enzyme activities compared with those in the controls, and the enzyme activities tended to increase with aging. From this, it is deduced that hypertension activates lysosomal enzyme activities in aortic endothelial cells. The differences in the activities of NAGase, cathepsin B and cathepsin D between hypertensive and control animals increased markedly with advancing age. These activated lysosomal enzymes seem to be involved in the developmental mechanism of arterial endothelial cell injury in hypertension and in further development of hypertensive vascular changes.

Acetylglucosaminidase↗
PubMed1988

Bacteroides gingivalis fimbriae stimulate production of thymocyte-activating factor by human gingival fibroblasts.

In a previous report (Y. Ohmori, S. Hanazawa, S. Amano, T. Miyoshi, K. Hirose, and S. Kitano, infect. Immun. 55:947-954, 1987), we showed that human gingival fibroblasts spontaneously produce thymocyte-activating factor (FTAF), which stimulates mitogen-induced thymocyte proliferation. In the present study, we examined the effect of Bacteroides gingivalis fimbriae on FTAF production by the cells, because the fimbriae may be involved in attachment of the organism to periodontal tissues. We show here that the fimbriae bind to the cells, which may subsequently lead to the stimulation of FTAF production by the cells.

Animals↗