Search PubMed⌕ Search

Biomedical subjects

C Yasui

Publications and source records attributed to C Yasui.

25 records · Page 2Linked to original sources
PubMed1990

Translocation of protein kinase C from cytosol to membrane fractions in human epidermal keratinocytes by recombinant human interferon-gamma.

The activation of protein kinase C involves its translocation from a cytosol fraction to a membrane fraction. Effects of interferon-gamma (IFN-gamma) on the epidermal protein kinase C were investigated. The treatment of recombinant human IFN-gamma on intact human epidermis resulted in the translocation of protein kinase C from a cytosol to a membrane fraction. The human IFN-gamma had no translocation effect on pig epidermal protein kinase C. Tumor promoter, 12-o-tetradecanoylphorbol-13-acetate (TPA), and a membrane-permeable diacylglycerol analogue, 1-oleoyl-2-acetylglycerol (OAG), both of which are well-known activators of protein kinase C, translocated the epidermal protein kinase C. The IFN-gamma had no direct effect on the epidermal protein kinase C; the addition of the IFN-gamma to partially-purified pig epidermal protein kinase C had no effect on its activity. The effect of the IFN-gamma on human epidermal protein kinase C appears to be through the species specific IFN-gamma receptors. It has been reported that the epidermal beta-adrenergic adenylate cyclase response is decreased following the TPA- (and OAG-) induced activation of protein kinase C. Human recombinant IFN-gamma, however, had no effect on the beta-adrenergic response of the human epidermis. Our results indicate that IFN-gamma affects intact keratinocytes in vitro, resulting in the activation of protein kinase C, which might be related to the physiological effect of IFN-gamma on keratinocyte.

Animals↗
PubMed1990

Ultraviolet action spectrum for intracellular free Ca2+ increase in human epidermal keratinocytes.

Effects of UV on normal human epidermal keratinocytes were studied by measuring the intracellular free Ca2+ concentration ([Ca2+]i) using fluorescence ratio imaging (fura-2-AM). Upon UV irradiation the [Ca2+]i increased sharply after a certain lag time, and the UV sensitivity was higher at lower temperatures. Statistically the distribution of [Ca2+]i became broader as the mean values became larger, and the number of affected cells increased sharply above a certain fluence (light intensity x time [photons/cm2]) at all wavelengths studied (200-400 nm). The action spectrum showed a single peak at about 230 nm and decreased gradually toward longer-wavelength UV regions.

Calcium↗
PubMed1989

Establishment of a cell line producing basement membrane components from an adenoid cystic carcinoma of the human salivary gland.

A new cell line has been established from an adenoid cystic carcinoma arising in the submandibular gland of a 63-year-old woman. The cultured epithelial-like cells grew vigorously and adhered together to form a sheet. Immunohistochemical stainings for type IV collagen, laminin and fibronectin were clearly positive in the intercellular matrix and on the surface of the culture cells. Chondroitin 6-sulfate proteoglycan and heparan sulfate were also detected. Ultrastructural studies showed that the cells had abundant rough endoplasmic reticulum and a well-developed Golgi apparatus. Rough endoplasmic reticulum near the cell surface was markedly dilated, and contained material of low electron density. This cell line would be useful for biological and biochemical studies on the mechanisms by which the stromal component is formed.

Basement Membrane↗
PubMed1989

Effects of beta-D-xylosides on proliferation and matrix formation of adherent fibroblastic cells in mouse bone marrow culture.

Mouse bone marrow cells were seeded on small pieces of cover glasses placed in culture dishes, and after 3 days, the pieces of glass to which only small spindle cells adhered were transferred to another dish containing fresh medium. The adherent small spindle cells proliferated and some of them became large polygonal cells with abundant cytoplasm. When phenyl beta-D-thioxyloside (0.5 mM), an artificial initiator of chondroitin sulfate chain synthesis, was added to the culture medium, the cells showed a marked increase in number as compared to controls, with conversion of about 35% of the cells to large size cells. Immunohistochemical staining with monoclonal antibodies showed that the intercellular matrix of adherent cells consists mainly of a large proteglylcan with chondroitin 6-sulfate side chains. By histochemical analysis, the amount of chondroitin sulfate was shown to be greater in the intercellular matrices of xyloside-treated groups than those of control cultures. The amount of chondroitin sulfate in the growth medium of the adherent cells, as measured by uronic acid analysis, was also significantly increased by treatment with phenyl beta-D-thioxyloside compared with controls.

Animals↗
PubMedDate not supplied

Topical cooling assisted hepatic resection of segment 7 and 8 oriented by en-bloc interruption of the targeted portal pedicles.

BACKGROUND/AIMS: The crucial points of hepatic segmentectomy include an accurate mapping of proposed segment(s) to be resected and minimization of intra-operative blood loss. This study reports a surgical technique of hepatic resection for segment 7 and 8, and a benefit of supplemental use of topical cooling during consecutive right hepatic inflow occlusion. METHODOLOGY: From January 1993 to December 1996, ten hepatocellular carcinoma patients with pathologic livers underwent hepatic segmentectomy for segment 7 and 8. The mapping of the target segments was guided by en-bloc test occlusion of the relevant portal pedicles and subsequent discoloration, often after the opening hilum method. Of these, five tumors were resected with topical cooling by ice slush seeding during consecutive right inflow occlusion (cooling group) and the remainder without cooling (Normothermic group). In the normothermic group, inflow occlusion was carried out by cyclic clamping and unclamping method. RESULTS: The inflow occlusion time was 54 +/- 9.4 min in the cooling group, much longer than in the normothermic group. Although the post-operative peak transaminase values were twice as high as those in the normothermic group, the blood loss was significantly less, and there was no detrimental effect of prolonged, consecutive ischemia on the other intra- and post-operative data. CONCLUSIONS: En-bloc taping of the target portal pedicles with or without the opening hilum method is useful in the mapping of segments, and the use of topical cooling is beneficial in prolonged inflow occlusion during complicated right-sided segmentectomy.

Adult↗
PubMedDate not supplied

Laparoscopic partial hepatectomy.

This article describes the surgical techniques and indications of laparoscopic partial hepatectomy, which is not as widely available as laparoscopic cholecystectomy. Three patients with hepatocellular carcinoma and associated severe liver cirrhosis were candidates for this technique from July 1993 to August 1994. The tumor size was 4 cm or less and all the tumors were located in segment 5 or 8 which had grown nodularly and protruded from the liver surface. A microwave tissue coagulator was used for parenchymal dissection under ultrasonographic guidance in a gas-less method with or without low-pressure pneumoperitoteum of 4 mmHg. The principle of dissection consists of tissue coagulation and fragmentation with dissecting forceps. Three hepatectomies were performed uneventfully without blood transfusion and the patients rapidly returned to their preoperative conditions. The laparoscopic partial hepatectomy can be an option of treatment in selected cases where the tumor can be removed by minor, superficial resection.

Carcinoma, Hepatocellular↗