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Biomedical subjects

C Sato

Publications and source records attributed to C Sato.

At least 325 records · Page 18Linked to original sources
PubMed1985

Effect upon mitogenic stimulation of calcium-dependent phosphorylation of cytoskeleton-associated 350,000- and 80,000-mol-wt polypeptides in quiescent 3Y1 cells.

Rabbit antiserum raised against highest molecular weight microtubule-associated protein (MAP-1) of brain immunoprecipitated 350,000-, 300,000-, and 80,000-mol-wt phosphoproteins of rat embryo fibroblasts (3Y1-B). The 350,000-mol-wt protein was sensitive to heat as was brain MAP-1, but the 300,000- and 80,000-mol-wt proteins were not. These polypeptides were hardly phosphorylated in cells in the quiescent G0 phase but were rapidly phosphorylated after addition of serum, epidermal growth factor, phorbol ester, insulin, or transferrin in the presence of calcium ions. All these agents also induced incorporation of [3H]-thymidine into DNA. These polypeptides were detected in isolated microtubules and cold-resistant filaments by immunoblotting. Since the 350,000-mol-wt polypeptide was detected in the membrane, the cytoskeletons, and the nucleus, and has been suggested to function as a linker, its rapid phosphorylation might represent an early process in transduction of the signal of mitogenic stimulation to the nucleus.

Animals↗
PubMed1985

Test Medium for the Growth of Nitrosomonas europaea.

A mineral medium for studying the growth of Nitrosomonas europaea was developed and examined. The medium was defined in terms of chemical speciation by using chemical equilibrium computer models. The medium significantly increased the metabolic activity of the organisms compared with previously developed media, yielding a specific growth rate as high as 3.0 day (generation time, 5.5 h). The specific growth rate was enhanced by increasing the inoculum and was linearly correlated with the inoculum-to-total-culture volume ratio on a semilog scale. A reproducible growth rate for N. europaea was obtained with this medium under controlled experimental conditions.

Journal Article↗
PubMed1985

No elevated cell surface charge at mitosis in X-ray-irradiated mammalian cells.

Rounded mitotic cells showed 30% enhanced electrophoretic mobility (EPM) when compared to spindle-formed interphase cells. This increase in EPM that was not present in interphase cells that had been rounded chemically by EDTA is considered to reflect a structural change in the cell membrane during mitosis. X-ray irradiation induced a dose-dependent EPM decrease in both interphase and mitotic cells during a 4-hour period. During the next 20 h of incubation, EPM recovery took place in cells irradiated with 250R, but not in cells exposed to 1000R. EPM was enhanced during mitosis in cells irradiated with low doses, but was absent in cells irradiated with 1000R. The ratio of colony-forming cells and of electrophoretically recovered mitotic cells after 24 h of exposure showed a good statistical correlation. These results indicate that unrepaired membrane damage contributes to mitotic cell death after irradiation.

Animals↗
PubMed1985

Efficient culturing of human melanocytes from suction blisters.

The culturing of normal human melanocytes from the roof of suction blisters of adult oriental volunteers was carried out. Since the epidermal roofs of blisters did not contain any fibroblasts, and since keratinocytes did not attach to the culture dishes in the presence of PMA (phorbol 12-myristate 13-acetate), many melanocytes were obtained which grew well in the presence of PMA. This method is a very simple and easy way to establish pure melanocyte cultures.

Adult↗
PubMed1985

Serum antibodies against alcohol-treated rabbit hepatocytes in patients with alcoholic liver disease.

The existence of antibodies against alcohol-treated rabbit hepatocytes in sera of patients with alcoholic liver disease was investigated utilizing a 125I-labelled protein A assay. The sera, after two absorptions with normal rabbit hepatocytes, were incubated with hepatocytes isolated from rabbits which had been treated for 4 days with a daily dose of ethanol (1 g/kg body weight) intravenously. Serum antibodies against alcohol-treated hepatocytes were detected in 21 of 55 patients with alcoholic liver disease; this was associated with a distinct, mixed granular and linear fluorescence staining the surface of alcohol-treated hepatocytes. By contrast, none of 23 patients with other liver diseases who had no history of excessive alcohol intake showed the antibodies in their sera. The values of the antibodies of patients with alcoholic active cirrhosis and alcoholic hepatitis were significantly higher than those of other types of alcoholic liver disease. These results showed that antibodies against alcohol-treated hepatocytes are present in alcoholic liver disease with inflammation. The role of these antibodies on liver cell damage in alcoholic liver disease remains to be clarified.

Animals↗
PubMed1985

Amplification and enhanced expression of cellular oncogene c-Ki-ras-2 in a human epidermoid carcinoma of the lung.

The level of c-Ki-ras-2-specific mRNA was found to be markedly enhanced (10- to 20-fold) in a human epidermoid lung carcinoma transplanted into nude mice, compared with that in other lung carcinomas. Analysis of DNA revealed that c-Ki-ras-2 gene was amplified approximately 10-fold in this carcinoma, while c-Ha-ras, c-myc and c-sis were not amplified. Chromosome abnormalities were also observed in this carcinoma.

Aged↗
PubMed1984

Interaction of ethanol with acetaminophen metabolism in the baboon.

To evaluate the effects of ethanol on acetaminophen metabolism and toxicity, twelve female baboons were studied using three experimental designs. In the first one, animals fed ethanol chronically and their pair-fed controls received acetaminophen intravenously (40 mg/kg), and drug metabolism was studied for 6 hr in blood and urine. Elimination of acetaminophen from plasma was accelerated significantly in baboons fed alcohol chronically, and urinary excretion of mercapturic acid conjugate was increased. In the second, the experiments were repeated with the addition of ethanol infusion (120-160 mg/kg/hr). During ethanol infusion, elimination of acetaminophen from plasma was still accelerated significantly in baboons fed alcohol chronically. In the third experimental design, four pairs of baboons fed an alcohol or an isocaloric control liquid diet received, in addition, acetaminophen (85 mg/kg/day) in their respective liquid diets for 2 weeks. Liver histology was studied before and after acetaminophen feeding; SGPT, SGOT, SGDH, acetaminophen blood levels and acetaminophen urinary metabolites were also assessed. No morphological or functional liver alterations were found after chronic acetaminophen treatment, and urinary excretion of mercapturic acid conjugate was not increased in baboons fed alcohol chronically. Thus, our results in primates confirm that chronic ethanol consumption increases, whereas acute ethanol administration decreases, the excretion of mercapturic acid conjugate. When acute and chronic ethanol administration were combined, the effects tended to cancel each other out. A dose of acetaminophen which maintained blood levels similar to those recommended for humans did not produce deleterious effects in baboons drinking alcohol.

Acetaminophen↗
PubMed1984

Transient length responses of heart muscle in Ba2+-contracture to step tension reductions.

The transient length response of the cat papillary muscle in Ba2+-contracture to step tension reduction was found to comprise four different phases. It is tentatively suggested that the transient response is mostly determined by the kinetics of the attachment and detachment of cross-bridges between actin and myosin filaments, which vary appreciably with activation level of the muscle.

Animals↗
PubMed1984

Lacrimal gland accumulation of 67Ga-citrate in patients with Sjögren's syndrome.

The extent of 67Ga accumulation in the two lacrimal glands in patients with keratoconjunctivitis sicca (KCS) of Sjögren's syndrome was studied. Of the two main groups one consisted of 69 subjects without ophthalmic complaints (control group), the other consisted of 26 patients with KCS of Sjögren's syndrome. Of the 26 patients with KCS, 7 had been diagnosed as probable KCS (probable sub-group) and the other 19 had been diagnosed definite KCS (definite sub-group). About 3 mCi (111 MBq) 67Ga-citrate was injected IV into each subject and this was followed by scintigraphy at 24, 48, and 72 h after the injection of 67Ga. A positive finding in the lacrimal gland was noted in 64 of 69 subjects (92.7%) in the control group and in 7 of 7 patients (100%) with probable KCS. Three of 19 patients with definite KCS (15.7%) showed positive findings under scintigraphy. When the scintigraphic finding in the lacrimal gland is not positive in patients with suspected KCS of Sjögren's syndrome, they can then be diagnosed with little risk as definite KCS cases. Shirmer's test was performed on subjects in the probable and definite groups. There was statistical significance between the positive and equivocal or negative scintigraphic finding and Schirmer's values. These results suggest a correlation between gallium accumulation in the lacrimal gland and the tear production.

Adolescent↗
PubMed1984

Nuclear immunofluorescence by a monoclonal antibody against microtubule-associated protein-1 as it is associated with cell proliferation and transformation.

Monoclonal antibody against microtubule-associated protein-1 produced intranuclear immunofluorescent spots, which disappeared under growth-inhibited conditions caused by serum starvation and saturated cell density in untransformed cells. A change of medium to 10% serum gave rise to the reappearance of nuclear spots before the resumption of DNA synthesis. This reversible change of immunofluorescence was also caused by a temperature shift in rat 3Y1 cells transformed by Simian virus-40-A640 (temperature-sensitive in large T-antigen). The fluorescence decreased during S phase of the cell cycle. In contrast the transformed cells always showed nuclear fluorescence, irrespective of serum concentrations or the cell cycle. Growth-inhibited cells previously treated with detergent and salt revealed nuclear fluorescent spots. This result suggested antigenic modification.

Animals↗
PubMed1984

Co-localization of SV40 T antigen and p53 with immunological analogues of microtubule-associated protein-1 on the nuclear skeleton.

Rat SV-3Y1 cells were stained with double immunofluorescence. Treatment of cells with detergent and salt removed about 80% of the antigens and revealed immunofluorescent flecks of the SV40 large T antigen and p53 bound to the nuclear skeleton. These flecks exactly corresponded to the fluorescent spots produced by antibodies against microtubule associated protein-1. The MAP-1 analogues may function in the initiation of DNA synthesis through the interaction with T-antigen and p53.

Animals↗
PubMed1984

[Organization of microtubules and regulation of cell growth].

Microtubule organizing center is composed of a pair of centrioles and active pericentriolar materials. Its nucleating activity enhances at mitosis to organize a mitotic spindle. We raised a monoclonal antibody against microtubule associated protein 1. Indirect immunofluorescence by this antibody was located in the microtubule organizing center and in the nucleus. The intranuclear antigen was bound to the nuclear skeleton during interphase, and released to cytoplasm concentrating to the mitotic spindle and its poles. The nuclear immunofluorescence reversibly disappeared in growth-inhibited normal cells, but was always apparent in transformed cells.

Animals↗
PubMed1984

Differentiation-associated cellular complex formation of murine thymocytes with thymic stromal cells.

Properties of normal murine thymocytes forming in vitro cellular complexes with thymic epithelial-like stromal cells in the form of pseudoemperipolesis were studied. The complex-forming cells were low-buoyant-density blasts primarily localized to the subcapsular zone. After transition into small cortical lymphocytes, their capacity for complex formation was lost. The complex-forming cells were relatively resistant to cortisone acetate and low-dose (170 rads) whole-body X-irradiation. Their number increased sharply in the early stage of thymic regeneration, corresponding to an increase in the percentage of large thymic lymphocytes 4 to 5 days after cortisone treatment or X-irradiation. However, after the thymus was repopulated with small lymphocytes, the percentage of complex-forming lymphocytes decreased rapidly to the normal level. A possible relationship between a step in thymic leukemogenesis and intrathymic T-cell differentiation is discussed.

Animals↗
PubMed1984

[Reevaluation for overlooked signs of cervical smears in cases of uterine cervical adenocarcinoma].

Though the incidence of adenocarcinoma is not high, this cancer has been a matter for discussion on the grounds that mass screening frequently shows "false negative" cases. The purpose of this study was to clarify the factors which had caused a misdiagnosis through the re-investigation of patients' previous cervical smears. In spite of continuous smear tests at various intervals, there was a long delay in the diagnosis, ranging from 6 months to 5 years, in 14 patients out of 51 cases of cervical adenocarcinoma treated in our hospitals during the past 6 years. In 12 of these 14 cases a careful re-examination of previously overlooked smear preparations revealed definite signs of adenocarcinoma in most cases (86%). A cause of the delay in diagnosing adenocarcinoma seems likely to be related to cytological inspections rather than to the process of taking smears. Characteristics overlooked signs in the misdiagnosed smears were either "rosette-like" arrangements or "irregular clusters of sheet-like" arrangements. The rosette-like arrangements a pattern indicative of cervical adenocarcinoma, were found in 10 of the above cases (71%). The findings obtained suggest that for the diagnosis of cervical adenocarcinoma, cytological diagnosis by smear could be made even in the early pre-clinical stage and when cervical adenocarcinoma is suspected on a cytological basis in this stage, conization is also strongly recommended despite the punch biopsy.

Adenocarcinoma↗