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Biomedical subjects

Y Ohsaki

Publications and source records attributed to Y Ohsaki.

At least 91 records · Page 5Linked to original sources

Immunofluorescence localization of type I and type III collagen and fibronectin in mouse dental tissues in late development and during molar eruption.

Affinity-purified antibodies produced intense staining for type I collagen in alveolar bone matrix and predentine, and moderate staining in the dentine matrix, lamina propria, connective tissue invaginating into papillary layer of the enamel organ, dental sac and periodontal ligament. No staining occurred in oral epithelium, stellate reticulum, stratum intermedium, ameloblasts and odontoblasts. Fibronectin was distributed similarly except at the interface between the epithelial diaphragm and pre-odontoblasts where type I collagen was absent but fibronectin was present. In contrast, type III collagen showed strong staining in the periodontal ligament and lamina propria but no staining in bone matrix, predentine, dentine and at the interface between the epithelial diaphragm and pre-odontoblasts. The staining pattern for type III collagen was similar to that of type I and fibronectin in other tissues including endosteal reticular tissue, the connective tissue invaginating into papillary layer and the extracellular matrix of the pulp.

Alveolar Process↗

Effects of retinoic acid on receptors for epidermal growth factor in mouse palatal mesenchymal cells in vitro.

Retinoic acid (RA), one of the inducers of cleft palate in vivo, specifically increased the 125I-epidermal growth factor (EGF) binding capacity of embryonic palatal mesenchymal cells; the increase was completely inhibited by actinomycin D, suggesting that transcription is required for this change. When the increase in EGF receptors was related to the stimulation of DNA synthesis by EGF in the presence of various concentrations of RA, the maximum stimulation of [3H]-thymidine by EGF was at 10(-9) M RA, but the maximum increase in the number of EGF receptors was at 10(-6) M RA. Thus the increase in the number of EGF receptors cannot be related to EGF-stimulated DNA synthesis.

Animals↗

Immunocytochemical demonstration of simultaneous synthesis of types I, III and V collagen and fibronectin in mouse embryonic palatal mesenchymal cells in vitro.

An immunocytochemical study was made on the palatal mesenchymal cells obtained from mouse embryos during palatal development with special reference to synthesis of types of collagen and fibronectin in vitro. Most cells showed positive staining with antibodies against the four proteins examined. The staining for type I collagen was most intense among the four proteins and was distributed perinuclearly. The staining for type III collagen was quite similar as that for type I collagen but less intense, whereas that for type V collagen was weak and its staining pattern was different from those for types I and III collagen in that the surface of the plasma membrane, in addition to the perinuclear cytoplasm, showed weak staining for type V collagen. Antibodies to fibronectin showed perinuclear and extracellular fibrous staining. These data suggest that palatal mesenchymal cells synthesize types I, III, and V collagen and fibronectin simultaneously.

Animals↗

Immunoelectron microscopic localization of fibronectin in the smooth muscle layer of mouse small intestine.

We studied the ultrastructural distribution of fibronectin in the smooth muscle layer of mouse small intestine with affinity-purified antibodies using the immunogold technique. Fibronectin was present over the pericellular area extending from the cell membrane to the extracellular matrix beyond the basal lamina. Distribution of the glycoprotein over the pericellular area was heterogeneous, i.e., it was localized more abundantly in the narrow space between smooth muscle cells, the gaps having a width of 60-80 nm where the two dense bands in adjacent cells matched each other. Such localization suggests that fibronectin contributes to cell adhesion. Within the basement membrane, gold label was localized both in lamina lucida and lamina densa, more densely in the latter than in the former. Fibronectin was also co-distributed with collagen fibers in the extracellular matrix. Within smooth muscle cells, gold particles were observed on rough endoplasmic reticulum and secretory vesicle-like structures. These results suggest that smooth muscle cells synthesize fibronectin and secrete it as a component of the basal lamina and extracellular matrix.

Animals↗

Increased lipoperoxide value and glutathione peroxidase activity in blood plasma of type 2 (non-insulin-dependent) diabetic women.

The lipoperoxide values and glutathione peroxidase activity in blood plasma, along with the glutathione peroxidase, catalase and cupro-zinc superoxide dismutase activities in erythrocytes were investigated in 60 women with Type 2 (non-insulin-dependent) diabetes mellitus and in 71 healthy women. The mean lipoperoxide value and the mean plasma glutathione peroxidase activity in the diabetic patients were significantly higher than those in the control subjects (lipoperoxide p less than 0.001, plasma glutathione peroxidase activity p less than 0.01). The plasma glutathione peroxidase activities did not, however, correlate with the plasma lipoperoxide values. The erythrocyte glutathione peroxidase activity was approximately ten times higher than that of the plasma glutathione peroxidase activity, nor did they correlate with each other. In contrast to the findings of other authors on the activities of the protective enzymes in erythrocytes against oxidative damage, there were no significant differences of erythrocytes glutathione peroxidase, catalase and superoxide dismutase activities between diabetic and control women.

Adult↗

Gallium-67 scintigraphy, bronchoalveolar lavage, and pathologic changes in patients with pulmonary sarcoidosis.

The intensity of gallium-67 scintiscans, lymphocyte counts in bronchoalveolar lavage fluid, and pathologic changes were studied in 26 patients with untreated pulmonary sarcoidosis. Noncaseating granulomas were recognized with significantly greater frequency in stage 2 (80 percent; 8/10 cases) than in stage 1 (43 percent; 6/14 cases). Alveolitis showed little relation to the roentgenographic stage. There was a strong correlation between the intensity of gallium uptake in pulmonary parenchyma and the detection rate of granuloma; however, the detection rate of alveolitis was not statistically different from the intensity of gallium uptake. A highly significant correlation was revealed between the lymphocyte counts in bronchoalveolar lavage fluid and the intensity of alveolitis. These observations suggest that the gallium uptake reflects mainly the presence of granuloma, and the lymphocyte count in bronchoalveolar lavage fluid reflects the intensity of alveolitis in patients with pulmonary sarcoidosis.

Adolescent↗

[Studies on the sensitivity test of anticancer agents with special reference to double layer colony forming assay].

The necessity to assess the effect of chemotherapeutic agents on the patients beforehand treatment has been stressed. In 1977, Salmon & Hamburger developed a new method to evaluate the drug sensitivity using cell suspension derived from the patients. They called the method as "human tumor stem cell assay". Since then, many reports were published about the correlation between the clinical outcomes and the results of human tumor stem cell assay, and high relationship between them was documented. The present study was undertaken to evaluate the method using the modified system; double layer colony forming assay, cell growth curve, tritiated thymidine uptake and flow cytometry. The drugs used in this study were adriamycin (ADR) and cis-platinum (C-DDP). We chose the human small cell lung cancer cell line PC-6 as a target cell. The conclusions are follows. The effects of ADR and C-DDP were concentration dependent respectively. The time dependent effect of C-DDP on PC-6 was revealed by enhancement of lethal effect, when they were exposed to the drug for 24 hours. A possibility exists that reproductive death would take place among PC-6 by ADR, along with DNA injury. It is one of the explanations for reduction of colony formation in contrast to increase in cell number. The effect of C-DDP on PC-6 was diminished with time. This phenomenon was reflected on double layer colony forming assay, and was possible explanation for reduction of colony formation which was greater than that of expected from cell growth curve.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Division↗

[Effect of solcoseryl and combined therapy of solcoseryl and FT-207 for mice bearing meth-A tumor].

The effects of a combined chemotherapy of solcoseryl and FT-207 on tumor growth, delayed hypersensitivity and cell population of the spleen were studied using inbred BALB/c mice. Meth-A tumor cells (2 X 10(6] were inoculated into the back of 5 to 6 week old BALB/c male mouse. Animals were divided into three groups: Solcoseryl group, in which 0.04 mg of solcoseryl was injected intravenously three times before inoculation and four times after inoculation; Combined group, in which 1.2 mg of FT-207 and 0.04 mg of solcoseryl were injected intravenously four times after inoculation; FT-207 group, in which 1.2 mg of FT-207 was injected four times after inoculation, with out solcoseryl administration. Following results were obtained: Solcoseryl group showed enhanced immunity and tumor suppression; Decreased immunity due to FT-207 was recovered by administration of solcoseryl but no tumor suppression was observed and, Decreased T-cell population of spleen due to FT-207 was recovered by administration of solcoseryl. These facts suggested that solcoseryl was useful because of making recovery possible from decreased immunity due to chemotherapy.

Actihaemyl↗