PubMed Health⌕ Search

Biomedical subjects

Y Kamei

Publications and source records attributed to Y Kamei.

At least 19 recordsLinked to original sources
PubMed1997

The transcriptional co-activator p/CIP binds CBP and mediates nuclear-receptor function.

The functionally conserved proteins CBP and p300 act in conjunction with other factors to activate transcription of DNA. A new factor, p/CIP, has been discovered that is present in the cell as a complex with CBP and is required for transcriptional activity of nuclear receptors and other CBP/p300-dependent transcription factors. The highly related nuclear-receptor co-activator protein NCoA-1 is also specifically required for ligand-dependent activation of genes by nuclear receptors. p/CIP, NCoA-1 and CBP all contain related leucine-rich charged helical interaction motifs that are required for receptor-specific mechanisms of gene activation, and allow the selective inhibition of distinct signal-transduction pathways.

Amino Acid Sequence↗
PubMed1997

Selective antitumor activity in vitro from marine algae from Japan coasts.

In vitro selective antitumor activity was tested as a general screening parameter for biologically active substances from a wide range of species of seaweed, 1446 samples of 306 species of marine algae from Japan's coasts. The algae extracts were prepared successively first by phosphate buffered saline (PBS) and then by methanol, and then tested for in vitro selective antitumor activity against murine lymphoid leukemia L1210 cells and for low cytotoxic activity against NIH-3T3 normal cells. Strong cytotoxic activity against L1210 cells was found in 47 species of algae, also showing similar cytotoxicity to mouse NIH-3T3 normal cells. However, four species of green algae showed strong activity specifically against L1210 cells, with low cytotoxicity to normal cells. Such selective activity was conspicuous in two brown and two green algae extracts. In particular, methanol extracts from the green alga, Cladophoropsis vaucheriaeformis, exhibited high viability (86%) to normal cells, showing selective cytotoxicity to tumor cells. This alga extract was no cytocidalic, but cytostatic against L1210 cells. Furthermore, the results of a cytotoxic spectrum test with 9 cell lines including those of L1210 and NIH-3T3 demonstrated that this extract acted strongly only against leukemic cell lines L1210 and P388.

Animals↗
PubMed1996

A CBP integrator complex mediates transcriptional activation and AP-1 inhibition by nuclear receptors.

Nuclear receptors regulate gene expression by direct activation of target genes and inhibition of AP-1. Here we report that, unexpectedly, activation by nuclear receptors requires the actions of CREB-binding protein (CBP) and that inhibition of AP-1 activity is the apparent result of competition for limiting amounts of CBP/p300 in cells. Utilizing distinct domains, CBP directly interacts with the ligand-binding domain of multiple nuclear receptors and with the p160 nuclear receptor coactivators, which upon cloning have proven to be variants of the SRC-1 protein. Because CBP represents a common factor, required in addition to distinct coactivators for function of nuclear receptors, CREB, and AP-1, we suggest that CBP/p300 serves as an integrator of multiple signal transduction pathways within the nucleus.

Animals↗
PubMed1996

Visualization of protein kinase activities in single cells by antibodies against phosphorylated vimentin and GFAP.

Vimentin and glial fibrillary acidic protein (GFAP) are intermediate filament proteins expressed in the cytoplasm of various types of cells. The head domains of these proteins are phosphorylated by various protein kinases. Site- and phosphorylation-specific antibodies which recognize a phosphorylated serine/threonine residue in the head domains and its flanking sequence provide a useful tool to monitor and visualize protein kinase activities in single cells.

Amino Acid Sequence↗
PubMed1996

Immunosuppression by anti-ICAM-1 and anti-LFA-1 monoclonal antibodies of free and vascularized skin allograft rejection.

Immunosuppression by anti-adhesion molecule antibody of free or vascularized skin allograft rejection was investigated in rats. Lewis (LEW, RT11) rats were used as donors and Fisher (F344, RT11v1) rats as the recipients. When F344 rats were treated intraperitoneally (i.p.) with anti-intercellular adhesion molecule-1 (ICAM-1) mAb (1A29) (3 mg/kg/day) and anti-leukocyte function-associated antigen-1 (LFA-1) mAb (WT.1) (3 mg/kg/day) one day prior to grafting and daily after grafting for nine days, free skin graft survival was prolonged only slightly compared with that in control rats which were injected i.p. with a daily dose of 6 mg/kg of anti-TNP mAbs (H1-6-2) one day prior to grafting and daily after grafting for nine days. (Mean survival time [MST] of the free skin graft was 11.2 +/- 0.6 days in the control group and 13.4 +/- 0.3 days in the 1A29 + WT-1 treated group [p < 0.01], respectively.) On the other hand, the vascularized graft survival was prolonged significantly in anti-ICAM-1/LFA-1 mAbs-treated F344 rats as compared with that in control rats. (The mean vascularized graft survival time was 14.2 +/- 0.7 days in the control group and 21.5 +/- 1.9 days in 1A29 + WT-1 treated group [p < 0.002]). Our results suggest that interaction with ICAM-1 and LFA-1 is more important in the rejection of vascularized skin allografts than that of free skin allografts.

Animals↗
PubMed1996

The possibility of active form of vitamins A and D as suppressors on adipocyte development via ligand-dependent transcriptional regulators.

The study aimed to systematically examine the effects of fat soluble vitamins and their analogs on terminal differentiation of adipocytes on the cellular and molecular aspects. It is well known that fat soluble vitamins especially vitamins A and D inhibit the differentiation of adipocytes in cultured cells. Furthermore, it has been revealed that the low level of dietary fat soluble vitamins, especially vitamin A and carotenoid actively stimulate the development of adipose tissue, namely bovine marbling in vivo. We have shown that the expression of retinoic acid receptor (RAR) alpha and gamma, retinoid X receptor (RXR) alpha and beta, and vitamin D receptor (VDR) mRNA were abundant in rat adipose tissue and 3T3-L1 cells. The autoregulated amplification and reduction of RAR, RXR and VDR mRNA by their own ligands, were observed in 3T3-L1 cells. Finally, we proposed the model of vitamins A and D as suppressors on adipocyte development through retinoid/thyroid/vitamin D/fatty acid-activated/peroxisomal proliferator-activated receptor's subfamily.

3T3 Cells↗
PubMed1996

[Gynecological management of climacteric syndrome with psychiatric disorders].

PURPOSE: To discriminate patients with severe mental disorders from those complaining of menopausal symptoms, psychological tests were performed on patients who visited the menopausal clinic. The effectiveness of hormone replacement therapy (HRT) in patients with slight mental disorders was also evaluated. SUBJECTS AND METHODS: Patients with menopausal symptoms (n = 150, 41-59 yr. old) were interviewed by a psychiatrist (according to DSM-III-R) and classified as the climacteric syndrome group (C) and the mental disorder group (P). The patients were also evaluated by the Menopausal index (MI), Maudsley Personality Inventory (MPI) and Self-rating depression Scale (SDS). The patients with severe mental disorders were eliminated and the remaining patients with menopausal symptoms were treated with conjugated equine estrogen (0.625 mg/day) and medroxyprogesterone acetate (2.5mg/day) for 24 weeks. RESULTS: 1) Thirty six patients were diagnosed as P (24%) and seven of them were diagnosed as having major depression (4.7% of the all patients). 2) MPI-N (neurosis scale) in C was 16.2 +/- 10, and in P was 30.5 +/- 9.0, and SDS in C and P were 39.0 +/- 8.0, and 51.4 +/- 8.9, respectively. In both psychological test, P shows a significantly higher value than C (p < 0.01). 3) Ninety point six % of the patients responded. HRT was not effective in 63.2% of P, but when psychotropic drugs were combined, significant improvement (p < 0.05) was observed. CONCLUSION: One fourth of the patients were suspected of having mental disorders in the menopausal clinic, and 5% of the patients needed the care of the psychiatrist. And the application of MPI and SDS was useful in helping the gynecologist to differentiate and classify the mental disorders to some extent. The applicability and effectiveness of HRT for patients with mild mental disorders were suggested.

Adult↗
PubMed1996

Plasma levels of interleukin-1 receptor antagonist (IL-1ra) and severity of illness in patients with burns.

The present study was conducted to determine whether a plasma interleukin-1 receptor antagonist (IL-1ra) would reflect the severity of burn injury and to examine the relation between IL-1ra and the cytokines. We studied 24 burn patients in whom the total burn surface area (TBSA) accounted for at least 20% of the body surface, and in whom serial blood samples could be obtained beginning immediately after the burn injury. Plasma levels of IL-1ra were determined by enzyme-linked immunosorbent assay (ELISA). Plasma levels of tumor necrosis factor-alpha (TNF-alpha), IL-6, and IL-8 were also determined by ELISA. Endotoxin was measured by an endotoxin-specific synthetic substrate method. There was a significant correlation between the plasma levels of IL-1ra and TBSA during the first week following burn injury. The IL-1ra level was the highest immediately after the burn injury. The level decreased markedly thereafter, and again rose when infection occurred. The IL-1ra level was extraordinarily elevated in patients who developed concomitant sepsis, septic shock or the septic multiple organ dysfunction syndrome. The IL-1ra level on admission and the maximum IL-1ra level during the observation period were significantly higher in the patients who eventually died than in the survivors. There was a significant correlation between the level of IL-1ra and that of TNF-alpha, IL-6 or IL-8 during the observation period. No correlation was found between IL-1ra and endotoxin. The plasma IL-1ra level was closely correlated with the severity of inflammation and the clinical status of the burn patients, regardless of the infection. Results suggest that IL-1ra can serve as an index of the systemic inflammatory response syndrome (SIRS).

Adult↗
PubMed1995

Ligand-independent repression by the thyroid hormone receptor mediated by a nuclear receptor co-repressor.

Thyroid-hormone and retinoic-acid receptors exert their regulatory functions by acting as both activators and repressors of gene expression. A nuclear receptor co-repressor (N-CoR) of relative molecular mass 270K has been identified which mediates ligand-independent inhibition of gene transcription by these receptors, suggesting that the molecular mechanisms of repression by thyroid-hormone and retinoic-acid receptors are analogous to the co-repressor-dependent transcriptional inhibitory mechanisms of yeast and Drosophila.

Amino Acid Sequence↗
PubMed1995

Cloning and sequencing of the gene encoding the mouse vitamin D receptor.

The mouse vitamin D receptor (VDR)-encoding cDNA was cloned and the coding regions were sequenced. Comparison of the amino-acid sequence to that of humans and rats revealed high homology in the DNA- and ligand-binding domains. Divergence appeared in the internal region between the two domains.

Amino Acid Sequence↗
PubMed1995

Tractional elevation of Henle's fiber layer in idiopathic macular holes.

PURPOSE: We sought to clarify the morphologic features of macular hole development. METHODS: Using scanning laser ophthalmoscopy, we examined 47 eyes with macular holes before and after vitrectomy. Cases included three eyes with stage 1B disease (foveal detachment), 14 with stage 2 (break at the fovea), 21 with stage 3 (full-thickness macular hole), and nine with stage 4 (detached operculum), according to Gass's classification. Ten eyes with central serous chorioretinopathy served as controls. RESULTS: Radiating striae of Henle's fibers were seen around the elevated rim of the macular cyst or hole when the intraretinal structures were illuminated by helium-neon laser. Granularity was observed on the macular hole floor. A granular reflex corresponding to the macular break or hole, but no radiating striae were seen by argon blue laser. In 40 eyes in which macular holes were successfully closed by vitrectomy, radiating striae of Henle's fiber layer disappeared, and the normal foveal depression was restored. The ten eyes with central serous chorioretinopathy had a normal foveolar depression and no detectable radiating striae of Henle's fiber layer, despite full-thickness retinal detachment in the macular area. CONCLUSIONS: Tractional elevation of Henle's fiber layer with intraretinal foveolar cyst formation is the initial feature of macular hole development. A macular hole is formed when the anterior cyst wall containing Henle's fiber layer is operculated. Remnants of the photoreceptor cell layer remain on the hole floor in the early stage of macular hole development and subsequently degenerate.

Adult↗
PubMed1995

Infrared angiography of the anterior ocular segment.

We performed angiography with indocyanine green (ICG) and fluorescein using a scanning laser ophthalmoscope (SLO) in the anterior segments of seven normal and 35 diseased eyes. ICG angiography revealed the radical stromal vessels and minor arterial circle in brown irides, which were not detected by fluorescein angiography. High penetration of infrared fluorescence through the pigmented tissue and absence of extravasation of ICG facilitated demonstration of the fine structure of iris rubeosis and its origins from stromal vessels. In 11 diabetic eyes, the iris rubeosis showed three basic patterns of location: along the pupillary margin; originating from the iris root; and arising from stromal radial vessels near the collarette. ICG gonioangiography with SLO showed fine structure of angle rubeosis because of its high resolution and greater depth in focus. Rubeotic vessels in the chamber angle were perfused by neovascular trunks which arose from the iris root in all 12 rubeotic eyes. Rubeosis in the iris and the angle consistently showed no extravasation of the ICG dye, while fluorescein quickly leaked out. ICG angiography with SLO in the anterior ocular segment proved to be a useful means to study the structure and the hemodynamics of normal and newly formed vessels.

Adult↗
PubMed1995

Anterior cranial base reconstruction using a hydroxyapatite-tricalciumphosphate composite (Ceratite) as a bone substitute.

The craniofacial approach to cranial base tumors has widened the operability of tumors with intracranial invasion. However, the resulting skull base defect must be reconstructed adequately to prevent postoperative morbidity and mortality. We use hydroxyapatite-tricalciumphosphate ceramic (Ceratite) as a bone substitute material to reconstruct the skull base defect in combination with the pericranial flap, ensuring separation between the sinonasal cavity and epidural cavity. Although the nasal surface of the Ceratite block is left exposed directly to the sinonasal cavity, it was shown to be epithelialized within 6 months postoperatively. Our method is less invasive than any other conventional method and may offer more chance of curative resection of tumors with anterior skull base invasion.

Adenocarcinoma↗
PubMed1994

The prevention of adipose differentiation of 3T3-L1 cells caused by retinoic acid is elicited through retinoic acid receptor alpha.

Retinoids, especially all-trans retinoic acid (RA), have been shown to inhibit the differentiation of preadipose cells. It is important to human health, especially to obesity, that the regulatory system for the differentiation of adipocytes is well defined. Previously, we have shown that retinoic acid receptor (RAR) gamma 2 gene expression is up-regulated by RA in 3T3-L1 preadipose cells. In this study, the RAR system was dissected and the RA-regulated function in 3T3-L1 cells was assigned to one given receptor. We used three synthetic retinoids; (1) Ro 41-5253, a selective RAR alpha antagonist, (2) Ch 55, an RAR alpha, beta and gamma agonist, and (3) Am 80, an RAR alpha and beta agonist, which has less affinity to RAR gamma. Ro 41-5253 reverted RA-induced inhibition of the differentiation of 3T3-L1 cells. However, there was no significant reversion in RA-induced RAR gamma mRNA level by treatment with Ro 41-5253. In the case of RAR agonists, both Am 80 and Ch 55 strongly inhibited the differentiation of 3T3-L1 cells. However, Am 80 weakly increased RAR gamma mRNA content less than did Ch 55. These findings suggest, that RAR alpha is involved in the prevention of adipose differentiation by RA in 3T3-L1 cells. Moreover, there seems no causal relationship between the prevention of adipose differentiation by RA and the up-regulation of RAR gamma 2 gene expression by RA in 3T3-L1 cells. We have shown the functional heterogeneity of RA action through different RARs in 3T3-L1 cells.

3T3 Cells↗