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Biomedical subjects

Y Yoshimura

Publications and source records attributed to Y Yoshimura.

At least 181 records · Page 10Linked to original sources
PubMed1998

Developmental profiles of phosphorylated and unphosphorylated CREBs in murine calvarial MC3T3-E1 cells.

The cAMP-responsive element (CRE) binding protein/activating transcription factor (CREB/ATF) family plays a major role in the expression of skeletal-specific genes and skeletal tissue development. We analyzed the changes of the amount, degree of phosphorylation and binding activity of the CREB/ATF family in the course of development of the murine calvarial osteoblastic cell line MC3T3-E1 as an in vitro model system of bone formation. The amount of CREB in the whole-cell extract detectable by Western blot analysis was high through all stages of development and maximal in the proliferation stage. The degree of phosphorylation estimated with anti-phosphorylated CREB antibody changed greatly and reached high levels in the proliferation stage and early mineralization stage. The ratio of phosphorylated CREB to total CREB in the CREB-CRE complex was also examined by gel shift assay. Although the binding to the consensus/CRE probe reached almost equally high levels in the proliferation stage and early mineralization stage, the relative level of phosphorylated CREB in the CREB-CRE complex was different in these two stages. In the early mineralization stage, most CREB bound to consensus/CRE was phosphorylated, while both phosphorylated and unphosphorylated CREB were bound to consensus/CRE in the proliferation stage. ATF-1 was also detected as a minor component bound to the consensus/CRE probe. The alteration of the binding of CREB to consensus/CRE over the course of osteoblast development supports the hypothesis that CREB may regulate the expression of genes defining the developmental sequence of MC3T3-E1 cells.

Alkaline Phosphatase↗
PubMed1998

Localization of macrophages in the ovarian follicles during the follicular growth and postovulatory regression in chicken, Gallus domesticus.

Macrophages may be a potential regulator of ovarian functions. The goal of this study was to determine the changes in the macrophage frequency (number of cells per unit square of tissue) during follicular growth, ovulation, and postovulatory follicular regression in chickens. Cryostat sections of ovarian stroma containing primary follicles, small white follicles, and preovulatory and postovulatory follicles of laying hens were immunostained for macrophage using mouse anti-chicken macrophage monoclonal antibody. Macrophages were observed under a light microscope and counted by a computer assisted image analyzer. The frequency of macrophages in the theca layer was significantly greater in the small white follicles than in the primary follicles (P < 0.01) and also greater in the preovulatory follicles than in the small white follicles (P < 0.01). No significant differences were observed in the macrophage frequency between the third largest and largest preovulatory follicles. In the theca layer of postovulatory follicles, macrophage frequency was significantly greater than in that layer in the preovulatory follicles (P < 0.01); however, the frequency of macrophages decreased significantly in the Day 3 postovulatory follicles as compared with Day 1 postovulatory follicle (P < 0.05). These results suggest that macrophages may play an important role in the follicular development and regression of postovulatory follicles.

Animals↗
PubMed1998

The transepidermal absorption of prostaglandin E1 as a topical ointment: an experimental study of application over a rat skin flap.

Prostaglandin E1 (PGE1) ointment has been shown to improve the survival of skin grafts. However, the mechanism of the effects of PGE1 through topical application is unknown. A rat skin flap model was used to determine whether PGE1 is absorbed through the intact skin. The prostaglandin concentrations in the flaps in the study group were greater than those in the controls. It is suggested that PGE1 is absorbed through the skin.

Administration, Cutaneous↗
PubMed1998

Insulin-like growth factors and ovarian physiology.

OBJECTIVE: To review the available information regarding the roles of insulin-like growth factor (IGF)-IGF binding protein (IGFBP) system in ovarian physiology. DESIGN: Studies that specifically relate to the roles of ovarian folliculogenesis, oocyte maturation, and ovulation were identified through the literature and Medline searches. RESULTS: Numerous actions of the IGFs have been demonstrated in the ovary, including an enhancement of cell proliferation, aromatase activity, and progesterone biosynthesis. The ovarian IGF system, comprised of IGF-I and IGF-II peptides, IGFBPs and IGF receptors, plays a significant role in the process of follicular development. In addition, IGF-I stimulates the meiotic maturation of follicle-enclosed oocytes in vitro via the IGF-I receptors. IGFBP-3 significantly inhibit gonadotropin-induced ovulation and oocyte maturation by neutralizing endogenously produced IGF-I. Thus, the intraovarian IGF-IGFBP system play a significant role in the processes of follicular development, oocyte maturation, and ovulation. CONCLUSION: IGF-IGFBP systems have autocrine/paracrine regulatory actions in ovarian physiology. The disturbance of the IGF-IGFBP system in human ovaries may lead to an ovulation, disorders of androgen excess, and infertility.

Animals↗
PubMed1998

Role of beta 1 integrins in human endometrium and decidua during implantation.

The present study was undertaken to investigate the expression and function of beta 1 integrins in human endometrium and decidua. Fluorescence-activated flow cytometry demonstrated the greater expression of the beta 1, alpha 1, alpha 2, and alpha 5 subunits of the beta 1 integrin family in cultured stromal cells from the midsecretory phase than in those of the early proliferative phase. The addition of estradiol (E2) and progesterone (P) to cultured stromal cells in the early proliferative phase increased the expression of beta 1 integrins in vitro. The immunohistochemical distribution of beta 1 integrins demonstrated predominantly glandular epithelial staining in the proliferative phase, and stromal and glandular staining in the midsecretory phase. Flow cytometry also demonstrated the expression of beta 1, alpha 1, alpha 2, alpha 3, alpha 5, and alpha 6 subunits of beta 1 integrin family in cultured decidual cells. Immunohistochemistry confirmed the beta 1 integrin cell surface phenotypes in cultured decidual cells observed by flow cytometry. In the subsequent experiment, the effects of antibodies against specific beta 1 integrin heterodimers on mouse embryo attachment and spreading were tested to identify the role of beta 1 integrins in early implantation. We developed assays for the attachment of mouse embryos and for trophoblastic spreading on cultured human decidual cells. The addition of antibodies directed against beta 1 and alpha integrin subunits to cultured decidual cells did not affect the rates of hatching or attachment of the blastocysts, whereas the outgrowth of embryos on the decidual cells was inhibited by their antibodies in a dose-dependent manner. Thus, beta 1 integrin in human endometrium and decidua may be important in mediating the organization of extracelllar matrix proteins derived from embryos during the early stage of implantation.

Adult↗
PubMed1998

Generation of immortalized murine forebrain cell lines expressing an alpha isoform of Ca2+/calmodulin-dependent protein kinase II.

Immortalized hybrid cells were generated by the somatic fusion of the cells from the forebrain of embryonic mouse with N18TG2 neuroblastoma cells. Three monoclonal hybrid cell lines, designated NF26, NF81, and NF83 (neuroblastoma forebrain hybrid cells), expressing an alpha isoform of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) were isolated, and their expression was demonstrated by immunoblotting and immunocytochemistry using a monoclonal antibody specific to the a isoform of the enzyme. The kinase activity of the hybrid cells was 2- to 3-fold higher than that of the parent neuroblastoma line N18TG2 cells. The neuronal origin of these lines was shown by their immunoreactivity to neurofilament protein, a neuron specific marker. Lines NF26, NF81, and NF83 are the first cell lines to express the gene of the alpha isoform of CaM kinase II in the brain.

Animals↗
PubMed1998

Effects of ageing and oestrogen on the localization of immunoglobulin-containing cells in the chicken ovary.

Immunoglobulins in the chicken ovary are important for transfer of immunity to chicks through the egg and for protection of the ovary from infection. The aim of this study was to examine the effects of ageing and oestrogen on the population of Ig-containing cells in the chicken ovary. The ovarian tissue of immature, young laying and old laying hens and that of immature birds treated with diethylstilboestrol (DES), progesterone or sesame oil (vehicle) was processed for paraffin wax sections. The sections were stained for IgG, IgM and IgA by an indirect immunostaining method and the population of cells positive for each Ig was analysed under a light microscope. The number of cells positive for IgG, IgM and IgA was significantly greater in the ovarian stromal tissue of young laying hens than in immature or old laying hens (P < 0.01). The number of IgG- and IgM-positive cells in the thecal layer of primary follicles of young laying hens was significantly greater than that in immature and old laying hens (P < 0.01) and there were significantly more (P < 0.05) IgA-positive cells in young laying hens than in immature birds. The number of IgG-, IgM- and IgA-positive cells was significantly (P < 0.01) greater in both the stromal tissue and the thecal layer of DES-treated birds than in the vehicle-treated birds. Progesterone had no significant effect (P < 0.05) on the population of Ig-positive cells. These results indicate that the number of Ig-positive cells increases as chickens mature and decreases with ageing, and that oestrogen may be involved in this process.

Aging↗
PubMed1998

Effects of age and gonadal steroids on the localization of antigen-presenting cells, and T and B cells in the chicken oviduct.

The effects of age and gonadal steroids on the localization of immunocompetent cells, including antigen-presenting cells that contain the major histocompatibility complex (MHC) class II antigen, and T and B cells in the chicken oviduct were studied. Oviductal tissues were collected from laying and immature hens treated with diethylstilboestrol (an analogue of oestrogen) or progesterone. Cryostat sections of the tissues were immunostained for MHC class II, CD3 (T-cell antigen) and Bu-1 (immature B-cell antigen), and examined under a light microscope and an image analysis system. MHC class II+, CD3+ and Bu-1+ cells were observed in the mucosal epithelium and stromal connective tissue of both the laying and immature hens. MHC class II+ cells in the oviductal stroma appeared in association with oviductal development during sexual maturation and increased with ageing thereafter. The infiltration of CD3+ and Bu-1+ cells into the oviductal tissues increased in young laying hens compared with immature hens and decreased in old laying hens compared with young laying hens. Diethylstilboestrol increased the population of MHC class II+ and CD3+ cells in the stroma of the infundibulum and vagina, but had no significant effect on the population of Bu-1+ cells in the oviduct of immature hens. Progesterone increased the population of CD3+ cells in the stromal tissue of oviductal segments from all hens, and of Bu-1+ cells in the mucosal epithelium of the infundibulum and magnum, but had little effect on the frequency of MHC class II+ cells in the oviduct of immature hens. There were typically more immunocompetent cells in the infundibulum and vagina than in the other oviductal segments in laying hens and immature hens treated with sex steroids. These results suggest that local immunity in the chicken oviduct is enhanced during sexual maturation and possibly decreases during ageing. Gonadal steroids may play a significant role in the regulation of local immunity in the oviduct. The effects of oestrogen and progesterone on the influx of these immunocompetent cells into the oviduct differs among cell types and oviductal segments.

Aging↗
PubMed1998

The effects of age and sex steroids on the macrophage population in the ovary of the chicken, Gallus domesticus.

The role of macrophages in the function of the hen ovary has not yet been described, although these cells may be an important regulator of ovarian function in mammals. The aim of this study was to determine the changes in the frequency of macrophages during ageing and follicular atresia, and the effects of sex steroids on the macrophage population in the hen ovary. Cryostat sections of ovarian tissues of immature, young laying and old laying hens and those of immature hens treated with or without diethylstilboestrol (DES) or progesterone were immunostained for macrophage cells using mouse anti-chicken macrophage monoclonal antibody. Macrophages were observed under a light microscope and counted using a computer assisted image analyser. The frequency of macrophages in both the stroma and theca of primary follicles was significantly greater in young laying hens than in immature and old laying hens and these cells were more frequent in old laying hens than in immature hens (P < 0.01). Macrophages were more frequent in atretic follicles than in normal follicles (P < 0.01). The number of macrophages in both the stroma and theca of primary follicles of DES-treated birds was significantly greater than in those of progesterone-treated and control birds (P < 0.01). Progesterone had no significant effect on the population of macrophages. These results suggest that macrophages in the ovary increase in association with sexual maturation of birds and atresia of follicles and decrease during ageing. Oestrogen may be one of the factors that affect the population of macrophages in the hen ovary.

Aging↗
PubMed1998

[A case of polyorchidism with embryonal carcinoma].

Polyorchidism is a rare anomaly with approximately 70 cases reported in the literature. We reported a case of polyorchidism with embryonal carcinoma, the first case, in one of 4 testes. Polyorchidism with malignancy had been reported in 5 cases and bilateral polyorchidism in 3 cases. Authors have not been clarified whether the incidence of malignancy in polyorchidism is high or low. But we have to treat the patients with polyorchidism carefully, because polyorchidism is highly associated with cryptorchidism.

Adult↗
PubMed1998

Effect of danazol on the pregnancy rate in patients with unsuccessful in vitro fertilization-embryo transfer.

OBJECTIVE: To determine the effect of danazol on in vitro fertilization-embryo transfer (IVF-ET) patients who failed to conceive in previous attempts despite having embryos with optimal morphology, whether endometriosis is present or not. STUDY DESIGN: In this prospective, randomized, controlled study, of 81 patients who experienced unexplained failures of IVF-ET despite having good-morphology embryos, 40 received danazol (400 mg/d orally for 12 weeks) following the unsuccessful IVF-ET cycle. The next IVF-ET was performed within three months of the first spontaneous ovulation after danazol administration. The remaining 41 patients constituted the control group, and in them the next IVF-ET was performed within six months after the previous failed cycle. RESULTS: Conception occurred in 16 of 40 (40%) danazol-treated patients at the subsequent cycle and showed a significant increase when compared with 8 of 41 (19.5%) control subjects (P < .05), though the number of embryos with optimal morphology decreased after danazol treatment. CONCLUSION: Danazol may be used for patients who have had repeated failures of IVF-ET despite having morphologically optimal embryos and may be useful for increasing receptivity of the endometrium in these patients.

Autoantibodies↗
PubMed1998

Disposition of the new antirheumatic agent ethyl 4-(3,4-dimethoxyphenyl)- 6,7-dimethoxy-2-(1,2,4-triazol-1-ylmethyl)quinoline-3-carboxylate (TAK-603) in rats and dogs.

The disposition of ethyl 4-(3,4-dimethoxyphenyl)-6,7-dimethoxy-2-(1,2,4- triazol-1-ylmethyl) quinoline-3-carboxylate (CAS 158146-85-1, TAK-603) after single oral dosing of 14C-labeled TAK-603 ([14C]TAK-603) at 10 mg/kg to rats and dogs was studied. In rats, the concentration of unchanged drug in plasma reached a peak (Cmax, 0.31 microgram/ml) 2 h (Tmax) after dosing of TAK-603 and declined biphasically with apparent half-lives (t 1/2 alpha, t 1/2 beta) of 1.5 and 3.6 h. In dogs, Tmax, Cmax, T 1/2 alpha, and t 1/2 beta were 1.7 h, 0.36 microgram/ml, 1.2, and 10.8 h, respectively. [14C]TAK-603 dosed orally was absorbed quantitatively in rats, while the extent of absorption in dogs was 54%. The bioavailability of TAK-603 was 53% and 42% in rats and dogs, respectively. In rats, 14C was distributed widely in various tissues, with relatively high concentrations in the liver, adrenal gland, and gut. The elimination of 14C from the thyroid was slower than that from other tissues. Unchanged TAK-603 and its pharmacologically active metabolite, M-I, which has the same potency as TAK-603, were distributed in articular soft tissues and synovial fluids, as target tissues, in rats and dogs, respectively. After oral administration of [14C]TAK-603, most of the 14C dosed was excreted within 48 h in rats and within 96 h in dogs. In both animals, a greater amount of the 14C dosed was excreted in feces than in urine. In biliary duct cannulated rats given [14C]TAK-603 intraduodenally, 69% of the dose was excreted in bile, and biliary 14C in part underwent enterohepatic circulation.

Administration, Oral↗
PubMed1998

[Successful removal of a left ventricular fibroma in a 10-year-old patient].

A 10-year-old girl with negative T wave in leads I, II, III, aVF, and V2-6 in the ECG was examined. The two-dimensional echocardiogram and the MRI revealed that she had a tumor in the free wall near the apex of the left ventricle. We removed the intramural fibroma (50 x 35 x 30 mm) of the left ventricle under cardiopulmonary bypass very carefully not to perforate the left ventricular cavity. After the removal, the defect was repaired by the sutures of the myocardial layers so that the volume inside the left ventricle could be kept and its shape could be maintained. She has been doing well without any trouble for 5 months after the operation.

Cardiac Surgical Procedures↗
PubMed1997

Determination of melanin in human hair by photoacoustic spectroscopy.

A highly sensitive photoacoustic spectroscopy for the determination of melanin in human hair has been developed. Both synthetic melanin and human hair were treated with 50% sulfuric acid. The melanin suspension was passed through the membrane filter to collect melanin, and the filter was transferred into a homemade photoacoustic cell, followed by measurement of the photoacoustic signals produced by 10 mW He-Ne laser beam. The good correlation between the method described in this paper and absorption spectrophotometry was confirmed quantitatively. The linearity observed between the photoacoustic signal and the weight of samples was in the range of 0.1-20 micrograms for synthetic melanin and 10-800 micrograms for human hair, with detection limits of 5 ng and 0.38 microgram, respectively.

Electron Spin Resonance Spectroscopy↗
PubMed1997

Phosphorylation-dependent reversible association of Ca2+/calmodulin-dependent protein kinase II with the postsynaptic densities.

The association of soluble Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) with postsynaptic densities (PSDs) was determined by activity assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunoblotting of the enzyme. Soluble CaM kinase II was autophosphorylated with ATP in the presence of Ca2+ and calmodulin, and then it was incubated with PSDs. Autophosphorylated CaM kinase II was precipitated with PSDs by centrifugation. The kinase that was not autophosphorylated did not precipitate with PSDs. These results indicate that the soluble previously autophosphorylated CaM kinase II associates with PSDs and forms PSD-CaM kinase II complex. A maximum of about 60 microg of soluble CaM kinase II bound to 1 mg of PSD protein under the experimental conditions. Ca2+-independent activity generated by autophosphorylation of the kinase was retained in the PSD-CaM kinase II complex. The CaM kinase II thus associated with PSDs phosphorylated a number of PSD proteins in both the absence and presence of Ca2+. When the CaM kinase II-PSD complex was incubated at 30 degrees C, its Ca2+-independent activity was gradually decreased. This decrease was correlated with dephosphorylation of the kinase and its release from PSD-CaM kinase II complex. These results indicate that CaM kinase II reversibly translocates to PSDs in a phosphorylation-dependent manner.

Animals↗
PubMed1997

Overexpression of alpha and beta isoforms of Ca2+/calmodulin-dependent protein kinase II in neuroblastoma cells -- H-7 promotes neurite outgrowth.

Since the alpha and beta isoforms of CaM kinase II are known to be expressed almost exclusively in the brain, we compared the effect of overexpression of the beta isoform of CaM kinase II with that of the alpha isoform. The subcellular distribution of the alpha isoform was different from that of the beta isoform, although the catalytic properties of the alpha and beta isoforms expressed in transfected cells were similar to those of brain CaM kinase II. The alpha isoform was found in the soluble fraction more than in the particulate fraction, whereas most of the beta isoform bound to subcellular structures. In the cell overexpressing alpha and beta isoforms of CaM kinase II, neurite extension was promoted when compared with the morphology of neo transfectants. Neurite outgrowth of cells overexpressing CaM kinase II was further stimulated by the treatment of 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7), a selective but not absolutely specific inhibitor of protein kinase C. The morphological change was rapid and observed within 1 h followed by H-7 treatment. Morphological changes, such as the number of cells with neurites and length of neurites were greater in the beta cells than in the alpha cells. Chelerythrine, a specific inhibitor of protein kinase C, also stimulated the neurite outgrowth of these cells. Some substrates of CaM kinase II related to neurite outgrowth were detected in cells overexpressing CaM kinase II stimulated with H-7. These results suggest that CaM kinase H and protein kinase C play an important role in the control of cell change, and that the subcellular distribution of CaM kinase II is important for regulating cellular functions efficiently.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗