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S Aonuma

Publications and source records attributed to S Aonuma.

At least 37 records · Page 2Linked to original sources
PubMed1987

A new agglutinin from the Tulipa gesneriana bulbs.

Two agglutinins with different agglutinating activity exist in Tulipa gesneriana bulbs. One is the T. gesneriana lectin which agglutinates yeasts as reported previously [Oda, Y. and Minami, K. (1986) Eur. J. Biochem. 159, 239-245]. The other agglutinin is a new one which agglutinates animal erythrocytes and was purified from the tulip bulbs using affinity chromatography on thyroglobulin-Sepharose 4B. The agglutinin agglutinated mouse and rat erythrocytes at a minimum concentration of 2 micrograms/ml and 30 micrograms/ml respectively, but did not agglutinate erythrocytes from other animals and yeasts even at a concentration of 1000 micrograms/ml. The agglutinin appeared homogeneous by disc gel electrophoresis at pH 4.3 and gel filtration. Its relative molecular mass was determined by gel filtration to be approximately 40,000. It was suggested that the agglutinin was composed of two different subunits of 26 kDa and 14 kDa by sodium dodecyl sulfate/polyacrylamide gel electrophoresis analysis. Binding of radioiodinated agglutinin to mouse erythrocytes indicated that the presence of a high-affinity site with a dissociation constant of 2.00 X 10(-9) M. In inhibition experiments thyroglobulin glycopeptides were the most potent inhibitors; thyroglobulin was also a potent inhibitor. Orosomucoid and mucin showed weak inhibition. The other glycoproteins, glycopeptides and sugars examined showed no inhibition.

Agglutination Tests↗
PubMed1987

Electron microscopy of Pseudomonas aeruginosa treated with sulbenicillin and dibekacin.

A possible mechanism responsible for the combined effects of sulbenicillin and dibekacin on Pseudomonas aeruginosa IAM 1007 was investigated. The bactericidal activity of the above two drugs in combination was very strong. The regrowth of test strains after removal of the drugs was suppressed markedly, even when they were exposed to sulbenicillin plus dibekacin at a subinhibitory concentration of individual drugs. Sulbenicillin caused elongation of the bacterial cells. At the early stage of elongation, no demonstrable changes of ultrastructure of the cell wall were observed. At the late stage, lysis of the peptidoglycan layer occurred and spheroplast was formed. However, most of the outer membrane of the cell wall remained intact. Sulbenicillin acts upon the peptidoglycan layer, but not on the outer membrane. Thus it is difficult for sulbenicillin alone to cause cell lysis. On the other hand, dibekacin caused destruction of ribosomes and lysis of the outer membrane of the cell wall. Both sulbenicillin and dibekacin act on the cell wall, the former on the peptidoglycan layer (the inner membrane) and the latter on the outer membrane. The combined use of sulbenicillin and dibekacin caused elongation of bacilli and severe destruction of the inner and outer membranes of the cell wall. These morphological changes occurred even when the concentration of the individual drug was lower than its minimum inhibitory concentration (MIC). Furthermore, the cells elongated by sulbenicillin were ruptured easily when treated with dibekacin subsequently. The bacilli treated with dibekacin at a concentration lower than MIC and then treated with sulbenicillin at a concentration lower than MIC showed a marked elongation of the cells, which indicated that the effects of sulbenicillin was enhanced by dibekacin. These findings suggested strongly that sulbenicillin and dibekacin act on cell wall constituents and that their effects were complementary and synergistic.

Cell Wall↗
PubMed1986

Studies on sperm capacitation using monoclonal anti-body--disappearance of an antigen from the anterior part of mouse sperm head.

C57BL/6 mice were immunized with cauda epididymal sperm from syngenic mice. A monoclonal antibody (TSC4) was obtained using a hybridization method with myeloma (P3U1) cells. The antibody was examined for its reactivity to sperm from different regions of the reproductive tract of male mice. The antigen was recognized only when the sperm reached the corpus epididymis. The area of antigen present on the sperm membrane was topographically restricted to the anterior part of sperm head. The antigen remained on the sperm after washing with phosphate buffered saline, disappearing, however, when sperm was capacitated.

Animals↗
PubMed1986

Electron microscopic study of the cell surface of dibekacin-treated Pseudomonas aeruginosa.

Electron microscopy of thin sections of Pseudomonas aeruginosa IAM 1007 treated with dibekacin revealed blebs, disintegration of the outer membrane of the cell wall and degenerative features of the cytoplasm. In the next experiment, the cell wall fraction was isolated from the mechanically disrupted cells, incubated with dibekacin and was subjected to electron microscopy, in order to find a clue to the action mechanism of dibekacin on the cell wall of Pseudomonas aeruginosa IAM 1007. As a result, it was found that unidentified substances were released from the surface of the cell wall and that the outer membrane of the cell wall disappeared. The degree of changes of the cell wall ultrastructure was almost proportional to the length of incubation with dibekacin. These findings strongly suggest that dibekacin directly disintegrates the outer membrane of the cell wall of Pseudomonas aeruginosa IAM 1007.

Cell Membrane↗
PubMed1985

Determination of immunoreactive antiarrhythmic peptide (AAP) in rats.

A sensitive and specific radioimmunoassay for antiarrhythmic peptide (AAP) has been developed, utilizing 3-(4-hydroxy, 5-[125I]iodophenyl)propionyl AAP and guinea pig anti-AAP serum. Synthetic AAP was used as a standard and the polyethylene glycol method was employed to separate free AAP from antibody-bound AAP. The minimum detectable dose of AAP was 0.2 pmol. In the assay system, immunoreactivity was shown not to be attributable to fragments derived from AAP, gelatin or collagen peptides, which sequences differ only by one amino acid from those of AAP. Immunoreactive (IR) AAP extracted from rat tissues and serum gave parallel dose-response curves to those of AAP. Thus, the AAP equivalents per g or ml of tissues measured in adult male rats were 203 pmol in heart, 166 pmol in kidney, 4 pmol in serum, and 2 to 6 pmol in the other tissues. IR-AAP was separated into two fractions by Sephadex G-25 chromatography. Fr. I was considered to have a larger molecular mass than AAP, while Fr. II appeared to have a molecular mass equal to AAP. Ratios of Fr. II in total IR-AAP were 50% in heart and 10% in kidney, while serum IR-AAP gave only Fr. II. The IR-AAP level in heart showed a positive correlation increase with age in rats.

Animals↗
PubMed1984

Osteogenesis bioassay and immunohistochemical and radioisotopic studies of parotin, parotid gland extract, and subunit.

Bioassay data support the hypothesis that the salivary gland participates in endocrine regulation of the development and maintenance of connective tissues. Epiphyseal cartilages become dystrophic in young growing rats after the resection of all major salivary glands. A subunit obtained from parotin, an extract of bovine parotid glands, contains the active agent for the presumed endocrine function of the salivary gland. Daily injections of 3 mg/rat of parotin or the subunit allow normal epiphyseal endochondral osteogenesis in salivary gland-deprived rats. The active agent appears to be secreted by the salivary acinar cells and resorbed through the striated ducts. Pancreatic islets and striated ducts of salivary glands share immunohistochemical activities for insulin, glucagon, and the subunit of parotin. Hyperglycemia and hypocholesterolemia occur in intact rats given 5 mg/day of parotin for 30 days. Together these data suggest endocrine functions of the salivary gland and possible interactions between the pancreatic islet and salivary gland.

Animals↗
PubMed1984

Purification and characterization of a fish lectin from the external mucus of ophidiidae, Genypterus blacodes.

A lectin was isolated from the external mucus of fish, Genypterus blacodes. This is the first lectin isolated from fish. The molecular weight of the lectin, determined by gel filtration, was approximately 32 000, whereas 8 000 was indicated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of 2-mercaptoethanol. Amino acid analysis demonstrated that the lectin contained large amounts (near 30% of the residues) of lysine, but no tryptophan. The lectin agglutinated mouse, rabbit and human erythrocytes at a concentration of 15.6 micrograms/ml. An inhibition test revealed that the lectin was strongly inhibited by N-acetyl-glucosamine, mucin and orosomucoid. Binding studies performed with iodinated asialo-orosomucoid indicated that the lectin contained a high affinity binding site with a dissociation constant of 1.1 X 10(-8) M. The lectin required the presence of calcium ion for both its hemagglutination and binding activity.

Amino Acids↗
PubMed1984

Studies on pharmacological activation of human serum immunoglobulin G by chemical modification and active subfragments. III. Mechanism of anti-ulcerous action of alkylated light chain (Fr. I-L).

The effects of a new anti-ulcer agent Fr. I-L, a reduced and carboxamide-methylated light chain of human immunoglobulin G, on defensive factors in gastric mucosa were studied. Fr. I-L increased the mucopolysaccharide contents (hexosamine, uronic and sialic acids) in the gastric mucosa of intact rats and inhibited the decrease of mucopolysaccharide contents in the gastric mucosa of rats with phenylbutazone-induced gastric ulcers. The activation of the biosynthesis of mucopolysaccharides by Fr. I-L was suggested by tracing the incorporation of 35SO4(2-) into the gastric mucosa. The administration of aspirin or phenylbutazone caused an increase of mucopolysaccharase activity in the gastric mucosa and the concomitant administration of Fr. I-L blocked the elevation of the enzyme activities. Fr. I-L also showed inhibitory activities on the local fibrinolysis and lipid peroxidation in the gastric mucosa.

Animals↗
PubMed1984

Mitogenic activity and in vitro fertilization inhibitory activity of Genypterus blacodes lectin.

A lectin which we purified from the mucous of Ophidiidae Genypterus blacodes showed a potent mitogenic activity which was comparable to that of concanavalin A (con A). On the other hand, the lectin treated with 2-mercaptoethanol showed an anti-mitogenic activity against con A and lipopolysaccharide (LPS). Lymphocytes were separated into a T cell rich fraction and B cell rich fraction by soybean agglutinin. The mitogenic activity of G. blacodes lectin was examined using these cells. It was suggested that the mitogenic activity of G. blacodes lectin was based on the stimulation of T cells. The lectin was also subjected to both the sperm agglutination and the in vitro fertilization tests in mouse. It was demonstrated that: a) the lectin receptors were ubiquitous on sperm; b) in vitro fertilization of mouse ova was completely blocked by the binding of the lectin to the zona pellucida of the ova.

Animals↗
PubMed1983

[The effects of parotin components on testosterone biosynthesis in rats].

During our studies on the active moiety of parotin, we succeeded in purifying MP-parotin (MW = 130000) and parotin-subunit (MW = 45000) from crude parotin. Furthermore, AA-1 (MW = 9100) was isolated after the tryptic cleavage of the parotin-subunit. AA-1 was the smallest unit ever obtained which had serum Ca-decreasing activity and circulating leucocyte-increasing activity together with the nature of specific localization in bone. Therefore, AA-1 was considered to contain the essential residues for parotin activity in its structure. Since crude parotin was also known to show andromimetic action, these parotin components reduced in size were assayed in this regard. A daily injection of MP-parotin (500 micrograms/kg), parotin-subunit (20 micrograms/kg) or AA-1 (20 micrograms/kg) was administered subcutaneously for two weeks to male rats weighing 200 approximately 220 g. The dynamics of the testicular biosynthesis of testosterone from 3H-pregnenolone and 14C-progesterone via delta 4, delta 5-pathway and the transition of delta 5 to delta 4-steroids were measured. MP-parotin and the parotin-subunit stimulated the pathway of pregnenolone----17-hydroxypregnenolone----dehydroepiandrosterone---- androstenedione----testosterone and resulted in the elevation of serum testosterone levels. Cyclic AMP levels in the testicular homogenate and the motility of epididymal sperm were also increased by the treatment. On the other hand, AA-1 showed no effect on these parameters. It was concluded that andromimetic activity, which is involved in MP-parotin or parotin subunit was independent of parotin activity on the bone tissue.

Androstenedione↗
PubMed1983

Osteogenesis bioassay and immunohistochemical and radioisotopic studies of a subunit of parotin, a parotid gland extract.

Bioassay data support the hypothesis that salivary glands participate in endocrine regulation of the development and maintenance of connective tissues. Resection of all three major salivary glands damages epiphyseal cartilages in young growing rats. A subunit obtained from parotin, an extract of bovine parotid glands, contains the active agent for the presumed endocrine function of salivary glands. Daily injections of 3 mg/rat of parotin or the subunit allow normal epiphyseal endochondral osteogenesis in salivary gland-deprived rats. The active agent appears to be secreted by the salivary acinar cells and resorbed through the striated ducts. Pancreatic islets and striated ducts of salivary glands share immunohistochemical activities for insulin, glucagon, and the subunit of parotin. Hyperglycemia and hypocholesterolemia occurred in intact rats given 1 to 5 mg/day of parotin for 30 days. These data together suggest endocrine function of the salivary glands and possible interactions between the pancreatic islets and salivary glands.

Animals↗
PubMed1983

Studies on pharmacological activation of human serum IgG by chemical modification and active subfragments. I. Induction of anti-ulcerogenic activity by chemical cleavage of interchain disulfide bonds in human IgG and properties of active subfragments.

Commercially available human IgG (native IgG) was passed through a DEAE cellulose column. Two fractions (Fr. I and Fr. II), responding equally against the anti-human IgG antibody were obtained. The carboxamide-methylated H and L chains from both fractions showed remarkable inhibitory activities on both the gastric ulceration and the gastric juice secretion in pylorus-ligated rats. The carboxamide-methylated L chain of rat IgG was also effective, while none of the human native IgG, Fr. I or Fr. II showed any effect. The reduction and the following alkylation of the interchain disulfide bonds were necessary for the induction of the biological activities of human IgG. Sulfonation of human IgG failed to induce the activities. Although the gastric acid secretion was clearly reduced by the administration of Fr. I-L (alkylated L chain of Fr. I), the gastric mucosal blood flow was not affected.

Alkylation↗