Search PubMed⌕ Search

Biomedical subjects

Y Toda

Publications and source records attributed to Y Toda.

At least 145 records · Page 8Linked to original sources
PubMed1983

Ultrastructural cytochemistry of complex carbohydrates in osteoblasts, osteoid, and bone matrix.

Glycosaminoglycans (GAGs) and glycoproteins are essential components for osteogenesis. We have examined rat osteoblasts, osteoid, transitional zone, and fully calcified bone matrix, utilizing Spicer's high-iron diaminethiocarbohydrazide-silver protein (HID-TCH-SP) method for sulfated glycoconjugates and Thiéry's periodate-TCH-SP (PA-TCH-SP) method for vicinal glycol-containing glycoconjugates. HID-TCH-SP stained cytoplasmic granules of osteoblasts. Stain deposits in the extracellular matrix were observed in decreasing amounts in osteoid, the transitional zone, and fully calcified bone matrix. Enzyme digestion with testicular hyaluronidase removed most HID-TCH-SP stain deposits. PA-TCH-SP staining was observed with increasing intensity in rough endoplasmic reticulum, Golgi saccules, and cytoplasmic granules. Collagen fibrils in osteoid were weakly stained with PA-TCH-SP, and their staining appeared even weaker in fully calcified bone matrix. In contrast, collagen fibrils in calcified cartilage stained intensely with the PA-TCH-SP method. Focal circular profiles (0.1-0.5 mumol in diameter), which lacked collagen fibrils but reacted moderately with PA-TCH-SP, were frequently seen in the transitional zone and fully calcified bone matrix, but were only occasionally present in osteoid. The presence of testicular hyaluronidase-resistant GAG and acid phosphatase in these focal areas suggests that they represent sites of GAG degradation. The eventual loss of HID-TCH-SP staining in the bone matrix suggests that removal of sulfated glycoconjugates may be a requisite for expansion of initial calcification sites and/or complete calcification.

Acid Phosphatase↗
PubMed1982

Extracellular and intracellular digestion of complex carbohydrates by osteoclasts.

The role of osteoclasts or chondroclasts in degradation and synthesis of complex carbohydrates was investigated using the high iron diamine-thiocarbohydrazide-silver proteinate method (HID-TCH-SP) for sulfated glycoconjugates and the periodate-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method for vicinal glycol-containing glycoconjugates. HID-TCH-SP stained the calcified cartilage matrix, the osteoclast ruffled border, vacuoles and heterophagosomes but not the Golgi apparatus and primary lysosomes. The size and number of HID-TCH-SP stain deposits progressively decreased from the calcified cartilage matrix to the ruffled border (p less than 0.001). Enzyme digestion with testicular hyaluronidase removed most HID-TCH-SP stain deposits averaging 13 nm. in diameter in the extracellular matrix, cytoplasmic vacuoles, and heterophagosomes of osteoclasts. Only sparse stain deposits averaging 8 nm. in diameter and presumed to be keratan sulfate remained in these sites after enzyme digestion. Osteoclast heterophagosomes contained the highest concentration of hyaluronidase-resistant material suggesting delayed degradation of keratan sulfate at this site. PA-TCH-SP strongly stained collagen fibrils in the calcified cartilage matrix. Reactive collagen fibrils were also observed in extracellular channels but only rarely were identifiable collagen fibrils observed in cytoplasmic vacuoles. A progressive decrease in the diameter of PA-TCH-SP reactive collagen fibrils was observed between the calcified cartilage matrix and the ruffled border region (p less than 0.001). PA-TCH-SP stained cisternae of rough endoplasmic reticulum, Golgi saccules, and primary lysosomes consistent with the synthesis and packaging of glycoprotein enzymes at these sites. These results indicate that the dissolution of sulfated glycoconjugates requires osteoclastic engulfment of degraded material and subsequent intracellular digestion, whereas the dissolution of collagen fibrils appears to be completed extracellularly.

Animals↗
PubMed1982

Isolation of recombinants doubly and triply drug-resistant to streptomycin, tetracycline and chloramphenicol by PEG-induced cell fusion of singly resistant staphylococcus aureus L-forms.

Various combinations of four substrains of Staphylococcus aureus L-form (strain STA-EMT-1), each of which was resistant to one of the following four drugs, streptomycin (SM), tetracycline (TC), chloramphenicol (CP) and erythromycin (EM), were submitted to polyethylene glycol (PEG)-induced cell fusion. PEG-induced cell fusion followed by enrichment culture in the liquid basal medium supplemented with penicillin G resulted in development of recombinants that were doubly drug-resistant to SM and TC, SM and CP, and TC and CP, but no recombinant doubly resistant to EM and TC, was obtained by treatment of a EM-resistant and TC-resistant substrains with PEG. No recombinants resistant to SM, CP and TC could be obtained by treatment of substrains resistant to SM, CP and TC, respectively, with PEG. But recombinants triply resistant to these three drugs were produced by two-step cell fusion; that is by fusion of a recombinant doubly resistant to two of the three drugs with a substrain resistant to the third drug.

Chloramphenicol↗
PubMed1981

Effect of physical training on exercise-induced sweating in women.

The effect of physical training on the time course of sweat rate in women has been examined. Physically untrained and trained young female subjects pedaled a bicycle ergometer at work rates of 483 and 981 kgm.min-1, for 2 h in summer and winter in an ambient environment of 30 degrees C db and 60% rh. The trained women also worked at 1,070 kgm.min-1 and the untrained at 391 kgm.min-1. Rectal temperature was measured, and capsule sweat samples were collected from the back every 5 min. Sweating was initiated more rapidly in the trained group than in the untrained group. The trained group working at a load of 981 kgm.min-1 exhibited a progressive decrease in sweat rate. This was not observed at a work load of 483 kgm.min-1. Hidromeiosis was rarely seen in the untrained group. However, in the untrained women who underwent 60 days of physical training, initiation of sweating occurred more quickly and hidromeiosis was observed. It was concluded that previous physical training improved women's capacity for useful sweating during exercise in a hot environment.

Adult↗
PubMed1980

The distribution of nickel in mice. An autoradiographic study.

Metallic restorations are corroded in the oral environment. Corrosion products penetrate into the tissues and are distributed throughout the body seeking certain organs and tissues as targets. The distribution patterns of nickel in albino mice were studied autoradiographically at various periods after an intravenous injection of 63Ni in order to locate the target organs and tissues of nickel. With short survival periods the highest uptake of 63Ni was found in the blood, kidney, urinary bladder, lung, eye and hair follicles. With long survival periods, 3 weeks, the distribution pattern was dominated by high uptake in the lung tissues, central nervous system, kidneys, hard tissues and skin. The distribution pattern in brown mice was similar to that in albino mice. However, the concentration in the eye and the skin was more pronounced. The importance of release of nickel from nickel containing dental alloys in nickel allergic patients is discussed.

Animals↗