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Y Toda

Publications and source records attributed to Y Toda.

At least 109 records · Page 6Linked to original sources
PubMed1988

Ultrastructural cytochemistry of trout arterial fibrils as elastic components.

The trout arterial wall contains numerous extracellular fibrils that are presumed to be elastic. However, the cytochemical properties of the arterial fibrils have not been studied. Thus, we have ultrastructurally and cytochemically examined these fibrils, utilizing routine uranyl acetate and lead (UA-Pb) double staining, the tannic acid (pH 7.0)-uranyl acetate (TA-UA) method as an electron-dense staining for elastin, and Thiéry's periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method to localize vicinal glycol-containing complex carbohydrates. The arterial fibrils, about 23 nm in thickness, were interwoven at random but frequently showed the circular alignment to the long axis of the aorta. Occasionally they appeared to coalesce side by side, and the coalesced portion tended to lose its affinity for UA-Pb stains. The TA-UA method stained the fibrils moderately to intensely and stained the coalesced parts of the fibrils more intensely. All of those TA-UA positive fibrils were completely removed after elastase en bloc digestion. The PA-TCH-SP method did not stain the arterial fibrils but stained another kind of much thinner interfibrillar filamentous structure. These results suggest that the fibrils in the wall of trout ventral aorta are elastin in nature and do not contain vicinal glycols, although the fibrils usually exist in a fibrillar form, which is unlike mammalian amorphous elastin.

Animals↗
PubMed1988

Serum levels of pancreatic enzymes in lean and obese subjects.

Serum amylase and trypsin, but not lipase, were significantly lower in obese subjects than in lean subjects. Serum amylase and trypsin, but not lipase, had significant inverse correlation with body weight. Low serum amylase was associated with low protein, fat and carbohydrate intakes per kg body weight, whereas low serum trypsin was associated with low carbohydrate intake per kg body weight. Low serum pancreatic enzymes readily increased with diet therapy. It is assumed that lowered serum pancreatic enzymes in obese subjects are somehow related to their diet intake. The mechanism through which pancreatic enzymes in the blood reflect the composition of food is unclear.

Adult↗
PubMed1988

Electron-microscopic observation of adherence of serotype c Streptococcus mutans to the enamel surface due to glucan synthesis.

Cellular adherence of three strains with water-insoluble glucan (IG)-synthesizing ability and a strain lacking the ability of serotype c Streptococcus mutans to the saliva-coated human enamel surface was examined by scanning (SEM) and transmission (TEM) electron-microscopy. SEM revealed that organisms of all strains used adhered directly to the enamel surface in the absence of sucrose. Cell-to-cell attachment was scarcely observed in the absence of sucrose. Cell-to-cell attachment via amorphous substance on the cell surface was observed by SEM when the strains with IG-synthesizing ability were incubated with the saliva-coated enamel in the presence of sucrose. TEM revealed that cell-associated enzymes of these strains synthesized filamentous and double-stranded fibrillar structures from sucrose. The strain lacking IG-synthesizing ability was unable to induce cell-to-cell attachment in the presence of sucrose, nor was it able to synthesize the amorphous substance. These results indicate that production of IG by cell-associated glucosyltransferase participates in cellular accumulation of serotype c S. mutans.

Bacterial Adhesion↗
PubMed1988

Black thyroid associated with minocycline therapy: histochemical and ultrastructural studies on the brown pigment.

The brown pigment found in the black thyroid, associated with minocycline therapy, was studied histochemically and ultrastructurally. The brown pigment was Fontana-Masson silver-positive, and was negative for iron, for autofluorescence under uv illumination, for periodic acid Schiff (PAS) and for acid-fast iodine peroxidase (AFIP) lipofuscin, and was bleached with potassium permanganate. The light and electron microscopic studies suggested that the pigment resembled melanin. Although the mechanism of the pigment deposition is not clear, a possible explanation may be that the pigment is related to direct oxidative degradation products of minocycline.

Aged↗
PubMed1987

Ultrastructural cytochemistry of oxytalan fibres in monkey periodontal ligaments with the high iron diamine method.

Monkey periodontal ligaments have been examined at the ultrastructural level to demonstrate the nature of reactive sites in oxytalan fibres. The high iron diamine (HID) and HID-thiocarbohydrazide-silver proteinate methods specific for sulphate groups, with and without prior oxidation with monopersulphate, were used. Oxytalan fibres were composed of bundles of microfibrils with a diameter of 11.5 +/- 1.7 nm (mean +/- S.D., n = 50). In cross section the microfibrils were found to have a denser periphery, giving them a 'tubular' appearance. The oxytalan microfibrils of non-oxidized specimens showed little reactivity with either HID method, except that the extracellular matrix material in close association with collagen fibrils stained weakly; in oxidized specimens, both HID methods strongly stained oxytalan microfibrils and weakly stained the extracellular matrix material. Such reactivity of oxytalan microfibrils was not altered by digestion with testicular hyaluronidase or chondroitinase ABC, performed prior to or after persulphate oxidation. Further, the sequential thiosulphation and HID method for the demonstration of disulphide and sulphhydryl groups stained oxytalan fibres moderately. These results indicate that the oxidative generation of sulphate groups in oxytalan fibres may occur from either disulphide or sulphhydryl groups, or both, rather than the result of unmasking of sulphated glycosaminoglycans.

Animals↗
PubMed1987

The effect of elastase on chickens with endogenous hyperlipidemia.

Elastase has been reported to have a multiplicity of activities which may be protective against atherosclerosis. The data reported here support those reports and show a clear antiatherosclerotic effect in hyperlipidemic chickens. We have shown here that a reduction in calcium and lipid accumulation in aortic tissue and possibly a plasma cholesterol lowering effect can be seen in the chicken when treated with elastase. The most important effect in this animal is probably to aid removal of lipid bound to elastin in the intima. This was achieved at a dose of only 600 U elastase while reductions in tissue calcium required 1800 U elastase.

Administration, Oral↗
PubMed1987

Ultrastructure of extracellular polysaccharides produced by serotype c Streptococcus mutans.

The ultrastructure of extracellular polysaccharides produced in colonies by two clinical isolates and that of a nitrosoguanidine-induced mutant of serotype c Streptococcus mutans with different polysaccharide-synthesizing abilities were compared electron-microscopically. A large amount of polysaccharide was produced from sucrose by colonies of typical serotype c strain MT8148R and a clinical variant MT6801R with an enhanced fructan-synthesizing ability. Transmission electron-microscopy (TEM) revealed that the polysaccharides consisted of three structural components, i.e., globular, single-stranded filamentous, and double-stranded fibrillar structures. These structures were ascribed to production of fructan, water-soluble glucan, and water-insoluble glucan, respectively. On the other hand, two kinds of structures, a globular body and an amorphous substance, were observed by scanning electron-microscopy (SEM). The former was composed of fructan, while the latter contained a mixture of water-soluble and water-insoluble glucans which formed filamentous and double-stranded fibrillar structures under TEM. Very small quantities of polysaccharides were formed in colonies of mutant NG7183, which was derived from S. mutans MT6801R. This strain was found to possess low glucan- and no fructan-synthesizing abilities. The polysaccharides produced in colonies of mutant NG7183 were composed only of filamentous and double-stranded fibrils under TEM. A small amount of amorphous substance was observed by SEM in colonies of NG7183.

Dextranase↗
PubMed1987

Vascularization of the hypothalamo-hypophysial complex in Japanese elasmobranchs: a scanning electron microscope study of blood vascular casts.

To study in detail vascularization in the hypothalamo-hypophysial complex in some Japanese elasmobranchs, injection casts of blood vessels were observed by scanning electron microscopy. Materials used were a gummy shark (Mustelus manazo), a cloudy dogfish (Scyliorhinus torazame) and a skate (Raja porosa). The vascular supply to the hypothalamo-hypophysial region of the elasmobranchs is carried out by the inferior hypothalamic arteries and their branches that originate from the internal carotid artery. In the gummy shark, a pair of inferior hypothalamic arteries send several branches to the median eminence running along the anterolateral sides of the distal adenohypophysis. These branches form the capillary plexus, displaying anastomosis and convolution at the ventral surface of the median eminence. The plexus assumes capillary glomeruli at the lateral region of the posterior median eminence. Numerous branches derived from the plexus are directed backward through the pars distalis, join with the capillary net work (which develop in the neuro-intermediate lobe) and are finally gathered together to form a thick hypophysial vein. The ventral lobe receives several arterial branches from the internal carotid arteries and carotid artery to form a unique vascular bed. Therefore, it is assumed that in elasmobranchs the hypothalamic control of the ventral lobe is weaker than that of adenohypophysial components.

Animals↗
PubMed1986

Effects of disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) on interleukin 1 production by macrophages.

The effects of disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) on the in vitro functions of guinea pig macrophages were studied. A high dose (1 mg/ml) of EHDP inhibited interleukin 1 (IL 1) production by oil-induced peritoneal macrophages stimulated with muramyl dipeptide (MDP), lipopolysaccharide (LPS), phorbol myristic acetate (PMA), heat-aggregated IgG2 or calcium ionophore A23187. On the other hand, low doses (less than 0.125 mg/ml) of EHDP augmented the MDP induced IL 1 production by macrophages. This biphasic effect was also observed when macrophages were exposed to EHDP at 37 C for 24 hr and then stimulated with IL 1 inducers. Superoxide anion generation induced by formyl peptide or PMA was not affected by preincubation of the macrophages with doses of EHDP up to 1 mg/ml. Adherence and spreading of macrophages was inhibited by EHDP in a dose dependent manner without affecting cell viability. These results demonstrated that EHDP acted on macrophages directly and modulated IL 1 production in vitro.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1986

Prophage type of recombinants produced by cell fusion between various combinations of lysogenic or non-lysogenic substrains from two Staphylococcus aureus L-forms.

Streptomycin (SM)- or erythromycin (EM)-resistant lysogenic and non-lysogenic substrains were produced from two Staphylococcus aureus L-form strains lysogenic for different prophages, namely, EMT-L (prophage alpha) and 209P (prophage beta). Cells of these L-form substrains were fused in various combinations using polyethylene glycol (PEG), and the frequency of recombinants selected as double resistance to both SM and EM and the prophage types of these recombinants were examined. In all the combinations, the frequency of recombinants was greater when the cells were treated with PEG than when they were not, and the difference was statistically significant (p less than 0.01) in 13 combinations. Combination between the lysogenic SM-resistant EMT-L substrain [EMT(Smr-alpha)] and lysogenic EM-resistant 209P-L substrain [209P(Emr-beta)] and the reverse combination, between 209P(Smr-beta) and EMT(Emr-alpha), resulted in a majority of recombinants harboring prophage beta. The former combination yielded recombinants that all held both prophage alpha and beta.

Bacteriolysis↗
PubMed1986

Effect of the composition of reversion medium on change of Staphylococcus aureus lysostaphin protoplasts to coccal forms and L-forms.

The experimental conditions under which protoplasts of Staphylococcus aureus strain MS353 (pCp) are converted to the coccal or L-form were investigated. Protoplasts prepared by treating coccal MS353 (pCp) strain with Lysostaphin formed various types of colonies (coccal form, L-form and mixed types) in about 50% yield when they were plated on reversion (R) medium consisting of 2% brain heart infusion, 0.5M sodium succinate, 0.01% bovine serum albumin, 20 mM MgCl2 and 0.6% agar. The L-form type colonies with a typical fried-egg appearance that developed on the R medium at an early stage gradually reverted to the coccal form through a mixed type stage in which a high density area first appeared in the periphery of the colony and then spread throughout the colony. The use of modified R medium without MgCl2 or R medium in which 0.5M sodium succinate as an osmotic stabilizer was replaced by 7.5% NaCl resulted in marked delay in the appearance of reverted cells. R medium without bovine serum albumin yielded atypical L-form type colonies, which contained masses of coccal cells with very irregular margins. On the other hand, R medium without MgCl2 but with penicillin G supported development of L-form type colonies at high rate (13-15%) from the inoculated protoplasts.

Culture Media↗