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Biomedical subjects

T Ohba

Publications and source records attributed to T Ohba.

At least 109 records · Page 6Linked to original sources
PubMed1990

Ca2+/calmodulin-dependent protein kinase II: localization in the interphase nucleus and the mitotic apparatus of mammalian cells.

Indirect immunofluorescence was used to determine the distribution of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) in rat embryo fibroblast 3Y1 cells, rat C6 glioma cells, and human epidermoid carcinoma KB cells. During interphase at growing phase, CaM kinase II was localized diffusely in the cytoplasm and in the nucleus. In the nucleus, the enzyme was localized within the whole nuclear matrix in which the enzyme was specially concentrated in nucleoli. During mitosis, CaM kinase II was found to be a dynamic component of the mitotic apparatus, particularly present at microtubule-organizing centers. In metaphase and anaphase, CaM kinase II was observed at centrosomes and between the spindle poles. During telophase, CaM kinase II was condensed as a bright fluorescent dot at the midzone of the intercellular bridge between two daughter cells, while tubulin was found at each side of the midbody. Colchicine, a microtubule inhibitor, disorganized the tubulin- and CaM kinase II specific fluorescent structure of mitotic 3Y1 cells. In cold-treated cells, CaM kinase II was localized predominantly at centrosomes. The localization of CaM kinase II in the cell nucleus and the mitotic apparatus suggests that the enzyme may play a role in the cell cycle progression of mammalian cells.

Animals↗
PubMed1990

1,24(R)-dihydroxyvitamin D3, a novel active form of vitamin D3 with high activity for inducing epidermal differentiation but decreased hypercalcemic activity.

1 alpha,25-Dihydroxyvitamin D3 (1,25(OH)2D3) is known to be a hormonally active form of vitamin D3 in the regulation of intracellular and extracellular calcium levels and of differentiation of myeloid cells and epidermal keratinocytes. We found that 1 alpha,24(R)-dihydroxyvitamin D3 (1,24(OH)2D3), a novel synthetic derivative of vitamin D3, is also active in regulating the differentiation of epidermal keratinocytes. 1,24(OH)2D3 had the same affinity as 1,25(OH)2D3 for a receptor isolated from the epidermis of newborn mice. The incubation of mouse epidermal keratinocytes with 1,24(OH)2D3 induced their differentiation in a time- and dose-dependent manner, as determined by the formation of a cornified envelope and an increase in the activity of transglutaminase. 1,24(OH)2D3 inhibited DNA synthesis of epidermal keratinocytes and also increased their cytosolic calcium level. These effects of 1,24(OH)2D3 were similar to, or rather more than, those of physiologically active 1,25(OH)2D3. However, 1,24(OH)2D3 was found to cause less hypercalcemia than 1,25(OH)2D3 when administrated intravenously to rats, suggesting its possible therapeutic value in psoriasis.

Animals↗
PubMed1990

Experimental comparison of radiographic techniques in the detection of maxillary sinus disease.

The radiographic examination of the maxillary sinus is usually accomplished by the Waters' projection. However, some lesions, such as the mucous retention cyst, postoperative maxillary cyst and maxillary sinus carcinoma, as well as some lesions extending into the maxillary sinus, may be shown by panoramic radiography. The present study was conducted to confirm the ability of panoramic radiography in the detection of maxillary sinus disease. The representation of a globular radiopaque mass at different locations in the maxillary sinus of a dry skull was compared in Waters' and panoramic projections. A mass with a diameter of 10 mm situated on the posterior wall or floor of the maxillary sinus was shown better by panoramic radiography. The Waters' projection was less effective; the mass, especially on the floor of the sinus, was not clearly demonstrated due to superimposition of the maxillary molar teeth.

Humans↗
PubMed1989

Primary intra-osseous carcinoma of the maxilla.

An unusual case of maxillary carcinoma, diagnosed as a primary intra-osseous carcinoma, is reported. This was differentiated from primary carcinoma of the maxillary sinus on the basis of the radiographic findings and the patient's dental history.

Female↗
PubMed1989

[A case of mandibular metastasis from primary hepatocellular carcinoma].

A mandibular metastasis which appeared as the first symptom from a hepatocellular carcinoma is reported. Bone metastasis related to hepatocellular carcinoma is relatively infrequent. Even less frequent is the occurrence of a mandibular metastasis as a prior symptom of hepatocellular carcinoma. In this case, also, the metastatic lesion was detected as hypervascular mass on a CT scan, thus the nature of lesion was disclosed before a biopsy was performed.

Biliary Tract↗
PubMed1988

Serum and growth factors rapidly elicit phosphorylation of the Ca2+/calmodulin-dependent protein kinase II in intact quiescent rat 3Y1 cells.

A 50-kDa protein was recognized in rat embryo fibroblast 3Y1 cells with an affinity-purified antibody against rat brain Ca2+/calmodulin-dependent protein kinase II (CaM kinase II). When the cytosolic extract from quiescent 3Y1 cells was immunoprecipitated with the antibody, the 50-kDa protein in the immunoprecipitate became phosphorylated in a Ca2+- and calmodulin-dependent manner following exposure to [gamma-32P]ATP. Moreover, the reaction proceeded through an intramolecular mechanism. These results suggest that the 50-kDa protein is a subunit of CaM kinase II in rat 3Y1 cells. The addition of 10% fetal calf serum to quiescent 3Y1 cells caused a rapid increase in the phosphorylation of the 50-kDa protein, which was immunoprecipitated with the affinity-purified anti-CaM kinase II antibody. The phosphorylation of CaM kinase II was detected as early as 20 s after the addition of serum, reached the maximal level at 2 min, and decreased to the basal level within 60 min. Platelet-derived growth factor and epidermal growth factor also elicited the phosphorylation of the 50-kDa protein in quiescent 3Y1 cells, while neither insulin nor 12-O-tetradecanoylphorbol-13-acetate did. Calcium ionophores, A23187 and ionomycin, also caused the phosphorylation of the protein in 3Y1 cells. Moreover, phosphopeptide mappings of the phosphorylated 50-kDa subunit generated in response to serum, EGF, and A23187 yielded patterns similar to that generated from the immunoprecipitated 50-kDa subunit phosphorylated in vitro. Phosphoamino acid analysis of the phosphorylated subunit demonstrated that serine residue was the major amino acid labeled under any condition. These results suggest that CaM kinase II undergoes phosphorylation in response to various stimuli that can increase the free Ca2+ concentration in the cytoplasm of quiescent fibroblast cells and therefore probably mediates at least some of the biological actions of growth factors.

Animals↗
PubMed1988

Modification of lethal, hypothermic and hyperphagic effects of sodium selenite by reduced glutathione in mice.

The effects of co-administration of reduced glutathione (GSH) on the lethality of sodium selenite (SS) and on SS-induced hypothermia and hyperphagia were examined in adult male ICR mice. Tissue GSH levels after s.c. injection were also determined. In the plasma, GSH concentration was significantly elevated up to 2 h after injection of 2 mmol/kg of GSH. Little change was observed in liver, and erythrocyte levels, the lethality of SS was enhanced by a similar dose of GSH. This enhancement, however, was observed only when SS was injected during the period when plasma GSH was elevated. These results suggest that the interaction between GSH and SS in plasma was the major contributor to the enhancement of SS toxicity. Hypothermia induced by SS was also enhanced by a 60-fold dose of GSH but not by a 6-fold dose of GSH. With respect to hyperphagia, GSH suppressed the effect of SS, probably because of depressing effect of co-administration of SS an GSH.

Animals↗
PubMed1988

Minerals and vitamin-A status in relation to gustatory functions for salt in healthy female college students.

Twenty-five healthy female college students were studied for the gustatory function tests for salt (NaCl) and some selected biochemical parameters including plasma retinol and plasma retinol-binding protein (PRBP). Plasma zinc (PZn) and retinol levels were comparable with those of good responders in tests of discrimination between two levels of NaCl in the previous report, but PRBP was lower in the present subjects. From the results of correlation analysis and stepwise multiple regression analysis, the individual student's discriminability of NaCl concentrations was related to the parameters regarding metabolic status of calcium (Ca), magnesium (Mg), sodium (Na), and selenium (Se). The detection threshold of NaCl concentration ranged from 1 to 60 mmol/liter and was related to PRBP. Plasma Zn was significantly positively correlated with both plasma retinol and PRBP, but significantly negatively correlated only for the detection threshold of NaCl concentration. On the basis of these results, the importance of vitamin-A nutrition and the relation of minerals such as Na, Ca, Mg, and Zn to the gustatory functions of NaCl was confirmed and a possible participation of Se to the functions was suggested.

Adult↗
PubMed1988

Adult T-cell leukemia/lymphoma in pregnancy.

Adult T-cell leukemia/lymphoma, a lymphocytic leukemia caused by human T-cell lymphoma virus-I (HTLV-I), is prevalent in southwestern Japan. A Japanese woman with adult T-cell leukemia/lymphoma in the third trimester of pregnancy was delivered of an infant by cesarean section. She did not breast-feed the child, who has remained free from HTLV-I infection.

Adult↗
PubMed1987

Transient hyperphagia after sodium selenite injection in mice.

Injection (s.c.) of Na2SeO3 (SS, 20-30 mumol/kg) into male mice initiated eating, which began about 20 min after injection and continued for about 3 h. This initiation effect was observed for mice of different ages and at different times of the day. Other findings of this study were: (1) early morning injection (30 mumol/kg) caused increased food intake, as examined by gastric content 3 h after injection, compared to daytime injection; and (2) SS-induced transient hyperphagia was observed at ambient temperatures of 10 and 22 degrees C, but not at 37 degrees C. This paper discusses these results in relation to SS-induced hypothermia.

Animals↗