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Biomedical subjects

M Aono

Publications and source records attributed to M Aono.

At least 91 records · Page 5Linked to original sources
PubMed1988

Thymic accessory cells required for the increased responsiveness of thymocyte subpopulations to interleukin 1-like monokine in guinea pigs.

The proliferative response of guinea-pig thymocytes to co-mitogenic stimulation with phytohaemagglutinin and the guinea-pig interleukin 1 (IL-1)-like lymphocyte-activating monokine was lost by removing the cells that adhere to a Sephadex G-10 (G-10) column or the cells of low density in a Ficoll-Conray gradient. The diminished response in the G-10 non-adherent thymocyte or high-density thymocyte fraction was restored by the addition of a macrophage-depleted G-10 adherent thymocyte fraction or a low-density, Ia-positive thymocyte fraction but not by the addition of peritoneal macrophages. These results suggest that the accessory cells which mediate the increased responsiveness of thymocytes to the IL-1-like monokine existed in G-10 adherent cell fractions and the cells with this accessory function were not macrophages. The accessory cells were shown to be of low density, glass-non-adherent, G-10-adherent, Fc receptor-negative, and Ia-positive. These results also suggest that the G-10-non-adherent and high-density thymocyte subpopulation, which is unresponsive or responds very little to the IL-1-like monokine by itself, acquires responsiveness to the monokine and proliferates by stimulation with the IL-1-like monokine and lectin in the presence of the accessory cells.

Animals↗
PubMed1988

Protection against alcohol-induced gastric mucosal injury by geranylgeranylacetone: effect of indomethacin.

The mechanism of gastric mucosal protection by an antiulcer agent, geranylgeranylacetone (GGA), against ethanol-induced injury was investigated. The experiments were conducted with groups of rats with and without intraperitoneal indomethacin pretreatment. Animals received intragastrically either a dose of GGA (200 mg/kg) or a vehicle, followed 30 min later by 1 ml of absolute ethanol. The rats were sacrificed after 30 min and the gastric mucosa was subjected to macroscopic and histologic assessment and the measurements of adherent mucus, its dimension and chemical composition. In the absence of GGA, ethanol produced advanced macroscopic necrosis (greater than 38%) and the extensive necrotic lesions were visible upon histologic examination. Pretreatment with GGA significantly reduced (p less than 0.001) the extent and depth of mucosal necrotic lesions caused by ethanol, and this protection was not thwarted by indomethacin. Evaluation of the adherent mucus and its dimension by Alcian blue uptake and inverted microscope technique revealed that GGA was also capable of preventing the untoward effect of indomethacin on the adherent gastric mucus gel and its thickness. Results of chemical analyses established that in the absence of GGA indomethacin caused an increase in mucus protein (15%) and a decrease in its covalently bound fatty acids (67%) and lipids (36%). The decrease in lipids was particularly reflected in the content of phospholipids. Indomethacin, however, had no apparent effect on the composition of gastric mucus elaborated in the presence of GGA. The results suggest that gastric mucosal protective action of GGA is not mediated by endogenous prostaglandins but rather appears to involve the metabolism of mucosal lipids.

Animals↗
PubMed1988

[Topical application of the controlled release strips containing ofloxacin (PT-01) in periodontal therapy].

The association of periodontopathic bacteria in the subgingival plaque with human periodontal disease has been well established. However, past attempts at reducing the level of pathogenic bacteria by using antibiotics as well as other antibacterial substance, so far, have not been fully successful. In this study, the effect of topical application of ofloxacin (OFLX), a synthetic antibiotic, was evaluated in relation to the clinical parameters. For this purpose, the new developed controlled release strips containing OFLX (PT-01), in which there were structurally immediate- and sustained-releasing portions, were used. 147 adult patients suffering from moderate to severe periodontitis were selected for this study. The patients had received no periodontal treatment previously and had taken no antibiotics within the preceding 6 months. Three different sites with a deep probing pocket depth (greater than or equal to 5 mm) were randomly selected in each patient, and were divided into three groups, i.e., PT-01 applied site (T), placebo-applied site (P) and control site (C). Periodontal treatments consisted of oral hygiene instruction and supragingival scaling on day 0 and 7, and subgingival scaling and root planing on day 14. PT-01 was applied in the periodontal pocket weekly on day 0 to 35, and clinical parameters on each site were recorded weekly. The results showed that, during first 14 days, significant reduction in the percentage of the sites which showed bleeding on probing, pus discharge or mobility of the tooth was observed in the PT-01 applied site. However in placebo and/or control group, no significant change in any parameters was observed in this period. While, after subgingival scaling and root planing, significant improvement was found at all sites in every clinical parameter. Especially, PT-01 applied sites showed significant improvement in the gingival index and bleeding on probing, compared to placebo-applied or control sites. These results suggest that weekly insertion of PT-01 in the periodontal pocket along with the subgingival scaling and root planing could have significant effect on the improvements in the gingival inflammation. Taken together, weekly application of PT-01 might have ameliorating effect as adjuncts of mechanical subgingival plaque control in the periodontal treatment.

Administration, Topical↗
PubMed1988

Several aspects of total genomic DNA transcription in a HeLa cell extract.

Several aspects of total genomic DNA transcription in a HeLa cell extract were described. (1) By using in vitro transcripts from total genomic DNA as probes, we elucidated several structures of short interspersed elements which are transcribed by RNA polymerase III (designated as Pol III/SINEs. (2) To know whether the repetitive sequence we cloned and sequenced comprises a major or minor family, we developed in vitro run-off transcription assay of total genomic DNA. (3) Unlike in vitro transcription of total genomic DNA from vertebrates, major in vitro transcripts from macronuclear total DNA of Tetrahymena were found to be tRNA themselves.

Animals↗
PubMed1987

Enhancement of the lipid content and physical properties of gastric mucus by geranylgeranylacetone.

The effects of intragastric administration of geranylgeranylacetone (GGA) on the content, composition and physical properties of the mucus component of the gastric mucosal barrier were investigated. One group of rats received twice daily for 3 consecutive days a dose of 100 mg/kg body weight of GGA, while the control group was subjected to daily doses of the vehicle. Sixteen hours following the last dose, the animals were killed, and their stomach was cut open and subjected to measurements of the adherent mucus gel content, analysis of its lipids and molecular forms of elaborated mucin, and evaluation of the viscosity and H+ retardation capacity. The results revealed that GGA elicited a 62% increase in the adherent mucus gel and caused a marked decrease in the proportion of the lower molecular weight mucin. Furthermore, the mucus of the GGA group exhibited a 67% higher content of covalently bound fatty acids and contained 46% more total lipids which were greatly (143%) enriched in phospholipids. The physical measurements demonstrated that mucus elaborated in the presence of GGA also exhibited 2.3 times higher viscosity and had a 32% greater ability to retard the diffusion of H+ than the mucus of the control group. The results suggest that GGA exerts a profound effect on the lipid content and the properties of gastric mucus associated with the maintenance of the mucosal integrity.

Animals↗
PubMed1987

Distribution of gastrin-releasing peptide (GRP)-like immunoreactivity in the rat.

Rat tissues were examined for gastrin-releasing peptide (GRP)-like immunoreactivity, using carboxy-terminus-specific antibody made against GRP (19-27), which is thought to be the biologically active site and to be common among species. The distribution of GRP-like immunoreactivity in the rat was similar to that of bombesin-like immunoreactivity. Sephadex G 50 chromatography revealed two peaks of GRP-like reactivity in the rat stomach. Immunohistochemical studies using the antiserum to GRP (19-27) revealed numerous nerve fibers in the mucosa of the rat stomach. In the antral mucosa, GRP-containing nerves were present mainly around the base of the antral glands. Some GRP-containing nerves were in contact with gastrin-containing cells and somatostatin-containing cells. GRP-containing nerve fibers were numerous in the middle portion of the oxyntic gland, where somatostatin-containing cells were also detected. None of the endocrine cells stained positively with anti-GRP serum. These results support the hypothesis that GRP is a neurotransmitter in the stomach and that the peptide plays a physiological role in the gastrointestinal tract.

Animals↗
PubMed1987

Effects of anti-GRP gamma-globulin on gastrin release and gastric secretion in the rat: evidence for the physiologic role of endogenous GRP in the regulation of gastric function.

To assess the effects of endogenous GRP on vagal gastrin release and acid secretion, anti-GRP gamma-globulin was infused in anesthetized rats to bind endogenously released GRP. Anti-GRP gamma-globulin blocked the gastrin-releasing effects caused by 4 micrograms/kg/hr of exogenous GRP infusion and suppressed gastrin release by electrical vagal stimulation. In spite of this suppression, anti-GRP gamma-globulin did not alter basal or vagal-stimulated acid secretion.

Animals↗
PubMed1987

Muramyl dipeptide induced augmentation of the proliferative response of thymocytes to phytohemagglutinin.

N-Acetylmuramyl-L-alanyl-D-isoglutamine (MDP) augmented the proliferative response of thymocytes to phytohemagglutinin (PHA). The augmenting effect of MDP disappeared by passage of glass-nonadherent thymocytes through Sephadex G-10 (G-10) column or by removal of low density cells by the Ficoll-Conray gradient centrifugation. The diminished augmenting effects of MDP on the proliferative response of glass-nonadherent-G-10 nonadherent thymocytes was restored by the addition of the G-10 adherent cells. When G-10 adherent cell fraction was extensively depleted of macrophages by glass adherence and EA-rosetting, it was found that neither the macrophage-depleted G-10 adherent cell fraction nor the macrophage fraction supported by itself the proliferative response of G-10 nonadherent thymocytes. However, addition of macrophage fraction together with the macrophage-depleted G-10 adherent cells did support the proliferation of G-10 nonadherent thymocytes. It was further shown that peritoneal exudate macrophages could be substituted for thymic macrophage fraction. These results suggested that both the G-10 adherent-glass nonadherent cells and macrophages were essential for the MDP-induced augmentation of the proliferative response of thymocytes to PHA and these cells exerted different accessory roles in this response.

Acetylmuramyl-Alanyl-Isoglutamine↗