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Biomedical subjects

S Amano

Publications and source records attributed to S Amano.

At least 199 records · Page 11Linked to original sources
PubMed1987

Chronic idiopathic intestinal pseudo-obstruction caused by acquired visceral neuropathy localised in the left colon: report of two cases.

Two cases of chronic idiopathic intestinal pseudo-obstruction (CIIP) are reported. One is a 51-year-old man, and the other is a 47-year-old woman. Both patients presented with severe constipation and barium enema showed a marked dilation of the right colon, and a narrowing in the left colon. Studies done on the motility of the colon and anorectum revealed normal resting pressure profiles of the anorectom, a normal recto-anal reflex, and a normal resting tone of the collapsed colon. Administration of methacholine chloride, however, provoked large, non-propulsive movements in the collapsed colon, which were inhibited by the administration of atropin sulfate. Histologic examination disclosed a marked decrease in neurons and an increase of Schwann cells in the myenteric plexus of the collapsed colon. CIIP due to acquired visceral neuropathy localised in the left colon, was diagnosed as a result of manometric and histologic findings. One case was cured surgically, by a left hemi-colectomy, and the other was cured medically using choline antagonists and laxatives.

Chronic Disease↗
PubMed1987

Biological characterization of interleukin-1-like cytokine produced by cultured bone cells from newborn mouse calvaria.

We have investigated the role of interleukin-1 (IL-1) and IL-1-like factor in the regulatory mechanisms of a bone remodeling system. To determine whether the bone cell itself produces IL-1-like cytokine, we examined bone cells cultured from newborn mouse calvaria. Bone cells migrating from fragments of newborn mouse calvaria were used in this study. We also used bone cells obtained by consecutive digestion of the calvaria with enzymes. These bone cells were cultured in fetal calf serum-containing alpha-MEM. IL-1-like cytokine activity was measured by incorporation of [3H]thymidine into C3H/HeJ thymocytes stimulated with PHA. When treated with lipopolysaccharide (LPS) from Escherichia coli 0111 B4, the cultured bone cells produced a significant amount of IL-1-like cytokine. The maximum concentration of IL-1-like cytokine was observed in culture supernatants of the bone cells cultured for 24 hours with the LPS in serum-free medium. The IL-1-like cytokine closely resembles IL-1 in some of its biological characteristics: stimulation of mitogen-induced thymocyte proliferation, stimulation of fibroblast proliferation, pyrogenicity, and molecular weight. These results show that cultured bone cells from newborn mouse calvariae produce an IL-1-like cytokine that closely resembles IL-1.

Animals↗
PubMed1987

Spontaneous production of thymocyte-activating factor by human gingival fibroblasts and its autoregulatory effect on their proliferation.

The purpose of this study was to examine whether human gingival fibroblasts produce a cytokine which modulates in immune and inflammatory responses including alterations in connective tissue metabolism in periodontal tissue. We found that a cultured human gingival fibroblast cell line (Gin-1) and freshly isolated human gingival fibroblasts produced thymocyte-activating factor(s), so we called the factor(s) fibroblast-derived thymocyte-activating factor (FTAF). Growth of the producing cell was itself modulated by the factor(s). Gin-1 cells spontaneously produced a significant amount of FTAF in a cell growth-dependent manner. Maximum activity was observed in conditioned medium from stationary-phase cells. The activity in conditioned medium of cultures lacking serum was significantly higher than that in those containing serum. Treatment of Gin-1 cell cultures with cycloheximide, an inhibitor of protein synthesis, markedly inhibited FTAF production. When Gin-1 cells were stimulated by triggering with muramyl dipeptide or sonicated extracts of Bacteroides gingivalis, FTAF production was significantly stimulated. Freshly isolated human gingival fibroblasts from gingival biopsies of healthy donors also produced FTAF which enhanced thymocyte proliferation. Peaks of thymocyte proliferation activity in conditioned medium from Gin-1 cells were observed in fractions having molecular weights of 25,000, 35,000, and 45,000, as determined by Sephadex G-75 column chromatography. The peak fractions (partially purified FTAF) significantly suppressed the proliferation of Gin-1 cells themselves as evaluated by [3H]thymidine uptake. The suppressive effect of partially purified FTAF was, at least partially, mediated by endogenous prostaglandin for the following reasons: addition of indomethacin, and inhibitor of prostaglandin synthesis, abrogated the suppressive effect; partially purified FTAF stimulated the production of prostaglandin E2 by the cells; and the suppression of cell proliferation was reinforced by addition of exogenous prostaglandins. These observations suggest that gingival fibroblasts play a significant role in regulation of cell growth of lymphocytes and in their own growth under physiological conditions and in pathological states in periodontal connective tissue.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1987

Studies on new antibiotics SF2415. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities.

A new species of Streptomyces is described for which the name Streptomyces aculeolatus is proposed. The organism produces new antibiotics SF2415A1, A2, A3, B1, B2 and B3 active against Gram-positive bacteria. Empirical molecular formulae of the antibiotics SF2415A1, A2, A3, B1, B2 and B3 were determined to be C26H31N2O5Cl, C26H30N2O5, C26H30N2O5Cl2, C26H33O5Cl, C26H32O5 and C26H32O5Cl2, respectively.

Animals↗
PubMed1986

Human purified interleukin-1 inhibits DNA synthesis and cell growth of osteoblastic cell line (MC3T3-E1), but enhances alkaline phosphatase activity in the cells.

We examined the effects of human purified interleukin-1 (IL-1) on DNA synthesis, cell growth, and alkaline phosphatase activity in the osteoblastic cell line MC3T3-E1 under both preconfluent and confluent culture conditions. Addition of IL-1 to the cells markedly inhibited their DNA synthesis and growth over the range 1-10 U/ml. Such significant inhibitory effects were observed in cells cultivated in 1 or 5% fetal calf serum (FCS)-containing alpha modification Eagle's medium (alpha-MEM), but not in alpha-MEM containing 10% FCS. In contrast, alkaline phosphatase activity was enhanced significantly by IL-1 in the cell line cultivated in 1% FCS-containing alpha-MEM. These results demonstrate that human purified IL-1 is effective in inducing the differentiation of osteoblastic cell MC3T3-E1.

Alkaline Phosphatase↗
PubMed1986

Elastase, collagenase, and cathepsin D activities in the aortas of spontaneously hypertensive and renal hypertensive rats.

In an attempt to clarify the roles of proteases in the developmental mechanisms of hypertensive vascular lesions, changes in activities of aortic elastase, collagenase, and cathepsin D in spontaneously hypertensive rats (SHR) and renal hypertensive rats were biochemically investigated. In SHR, elastase activity initially showed a significant increase, once two-fold higher than that in the control; but the activity tended to decrease earlier than that in the control. In both SHR and normotensive control rats collagenase activities tended to increase with advancing age. The activity in SHR was two-fold higher than that in the control at all ages examined. In both younger SHR and normotensive rats cathepsin D activities proved to be increased with advancing age, while in old rats the activities tended to decrease. The activity in SHR was three- to fivefold higher than that in the control at all ages examined. In renal hypertensive rats, the activities of elastase, collagenase, and cathepsin D increased gradually with increasing blood pressure, at levels significantly higher than those in the control. These findings suggest that the metabolisms of proteins such as elastin and collagen, expressed by these enzyme activities, are accelerated under hypertensive conditions.

Aging↗
PubMed1986

[Animal experiment studies of free transplantation of striated muscles].

Heterotopic autologous muscle transplants of the left soleus muscle were performed in 39 Wistar rats. In analogy to the method described by Hakelius, the muscle was implanted into the bed of the contralateral superficial flexor muscle of the fingers with a varying prestretch of 0, 25 and 50% of its original length at rest. The animals were sacrificed postoperatively after 5, 10, 20, 40 and 60 days and their musculature examined. It was found that revascularisation and reneurotisation depended on the degree of prestretching applied. If prestretching amounted to 25 and 50%, complete degeneration of the connective tissue of the transplanted muscle occurred. However, even if prestretching was only low, i.e. between 0 and 5%, only one-third of the muscle mass regenerated and was interspersed with connective tissue of low cellular and vascular content with cicatrisation. These findings were also seen--to a lesser degree--if the soleus muscle was only denervated. We can conclude from this that restretching plays a decisive role even in the transplantation of striated muscle, as far as revascularisation and reneurotisation are concerned, and that even under the most favourable conditions only part of the transplanted muscle retains its full functional capacity. Furthermore, direct nerve anastomoses between the pudendal nerve and a branch of the femoral nerve supplying the transplanted semitendinous muscle, were performed in four Syrian goats. It was found that neurotisation of the muscle via microanastomosis is preferable to diffuse reneurotisation via the transplant bed. However, problems arose in respect of the blood supply of the transplanted semitendinous muscle, when using the technique after Holle and Freilinger.

Animals↗
PubMed1986

Humoral antibody response against Bacteroides gingivalis-specific antigen recognized by monoclonal antibody in adult periodontal patients.

An antigen recognized by monoclonal antibody specific for Bacteroides gingivalis was purified in the presence of 0.5% (wt/vol) beta-octyl-glucoside by immunoadsorbent column chromatography. The purified antigen was homogeneous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and silver staining, and the pattern of SDS-PAGE agreed with that of immunoblotting. The molecule exhibited an apparent molecular weight of about 62,000 by SDS-PAGE. The antigen was sensitive to trypsin, Staphylococcus aureus V8 protease, DNase I and II, and heating, but insensitive to RNase and neuraminidase. By the enzyme-linked immunosorbent assay method, the purified antigen was not cross-reactive with rat polyclonal antibodies to each of several black-pigmented Bacteroides species, Fusobacterium nucleatum, Eikenella corrodens, and Actinobacillus actinomycetemcomitans. These results indicate that the purified antigen is specific for B. gingivalis. Humoral antibody titers in adult periodontal patients against the specific antigen were measured by the enzyme-linked immunosorbent assay. Serum immunoglobulin G antibody titers against the specific antigen in adult periodontal patients correlated significantly with the severity of periodontal disease. However, such significant correlation was not observed with serum immunoglobulin M antibody titers.

Adult↗