Biomedical subjects

M Yamaguchi

Publications and source records attributed to M Yamaguchi.

At least 793 records · Page 44Linked to original sources

PubMed1995

Inhibitory effect of zinc-chelating dipeptide on parathyroid hormone-stimulated osteoclast-like cell formation in mouse marrow cultures: involvement of calcium signaling.

A possible mechanism of zinc action inhibiting the PTH-induced osteoclast-like cell formation in mouse marrow culture system in vitro was investigated. Bone marrow cells were cultured for 7 days in alpha-minimal essential medium containing a well-known bone-resorbing agent parathyroid hormone (1-34) (PTH). Osteoclast-like cell formation was estimated with staining for tartrate-resistant acid phosphatase (TRACP), a marker enzyme of osteoclasts. The effect of zinc sulfate (10(-6) M) or beta-alanyl-L-histidinato zinc (AHZ; 10(-6) M) inhibiting the PTH (10(-8) M)-induced osteoclast-like cell formation was clearly seen in the absence or presence of theophylline (10(-4) M). However, zinc compounds did not inhibit the stimulatory effect of dibutyryladenosine 3',5'-cyclic monophosphate (DBcAMP; 10(-4) M) on osteoclast-like cell formation. The stimulating effect of PTH (10(-8) M) on osteoclast-like cell formation was clearly weakened (about 50%) in the presence of EGTA (1.0 mM) or dibucaine (10(-5) M). Phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator (10(-8) to 10(-6) M), clearly stimulated osteoclast-like cell formation. PMA effect was inhibited by the presence of AHZ (10(-6) M) or zinc sulfate (10(-8) M). However, the inhibitory effect of zinc compounds was not seen in the presence of both PTH (10(-8) M) and PMA (10(-6) M). The present findings suggest that zinc compounds inhibit PTH-stimulated osteoclast-like cell formation mediated through the Ca(2+)-dependent activation of protein kinase C.

Animals↗

PubMed1995

Zinc modulation of insulin-like growth factor's effect in osteoblastic MC3T3-E1 cells.

Whether the anabolic effect of insulin-like growth factor-I (IGF-I) in osteoblastic MC3T3-E1 cells is modulated by zinc, an activator of bone formation, was investigated in vitro. After subculture for 3 days, the cells were cultured for 72 h with IGF-I (10(-8) M). The peptide produced a significant increase of protein concentration, deoxyribonucleic acid (DNA) content, and cell number in the cells. These increases were markedly enhanced by the presence of zinc sulfate (10(-5) M), but not zinc-chelating dipeptide (beta-alanyl-L-histidinato zinc; 10(-5) M). Also, the cellular alkaline phosphatase activity was synergistically increased by the presence of both IGF-I and zinc sulfate. Thus, effect was not seen in the presence of both insulin (10(-8) M) and zinc sulfate (10(-5) M). The effect of zinc sulfate to enhance the IGF-I-increased alkaline phosphatase activity and protein concentration in the cells was clearly prevented by the presence of cycloheximide (10(-6) M), staurosporin (10(-8) M), or okadaic acid (10(-7) M) with an effective concentration. However, staurosporin had a partial inhibiting effect on the IGF-I or the IGF-I plus zinc-induced increases in cellular protein, although okadaic acid entirely blocked the IGF-I or the IGF-I plus zinc effect. The present study demonstrates that the anabolic effect of IGF-I in osteoblastic cells is enhanced by zinc ion. The enhancement by zinc may be mediated through the signaling pathway of protein kinase C and protein phosphatase in the cells.

3T3 Cells↗

PubMed1995

Differential effects of transforming growth factor-beta on osteoclast-like cell formation in mouse marrow culture: relation to the effect of zinc-chelating dipeptides.

The effect of transforming growth factor-beta (TGF-beta) on osteoclast-like cell formation in mouse marrow culture in vitro was investigated. The bone marrow cells were cultured for 7 days in alpha-minimal essential medium containing a well-known bone resorbing agent. Osteoclast-like cell formation was estimated with staining for tartrate-resistant acid phosphatase (TRACP), a marker enzyme of osteoclasts. The presence of TGF-beta (10(-13)-10(-11) M) caused a significant increase in the number of osteoclast-like multinucleated cells (MNCs); the maximum effect was seen with 10(-12) MTGF-beta. With a higher concentration (10(-10) M) of TGF-beta, the growth factor dramatically inhibited the 1,25-dihydroxyvitamin D5 [1,25(OH)2D3; 10(-8) M]-induced formation of osteoclast-like MNCs. This inhibitory effect was also seen in the formation of osteoclast-like MNCs stimulated by parathyroid hormone (10(-8) M), prostaglandine E2 (10(-6) M), and interleukin-1 alpha (50 U/ml). The stimulatory effect of TGF-beta (10(-12) M) on osteoclast-like MNCs formation was inhibited by zinc sulfate (10(-6) M) or zinc-chelating dipeptide [beta-alanyl-L-histidinato zinc (AHZ), 10(-6) M]. The stimulating effect of TGF-beta was markedly weakened by the presence of EGTA (0.5 mM), a chelator of Ca2+. The inhibitory effect of zinc compounds was not seen in the presence of EGTA. Moreover, the inhibitory effect of TGF-beta (10(-10) M), zinc sulfate (10(-6) M), or AHZ (10(-6) M) on osteoclast-like MNCs formation was not demonstrated in mature osteoclastic cells, although calcitonin (3 x 10(-8) M) significantly inhibited the osteoclastic formation. The present study demonstrates that TGF-beta has a stimulating and an inhibiting effect on osteoclast-like cell formation in mouse marrow culture, and that zinc can inhibit the stimulatory effect of TGF-beta.

Animals↗

PubMed1995

Expression patterns of DNA replication enzymes and the regulatory factor DREF during Drosophila development analyzed with specific antibodies.

Specific antibodies were prepared against Drosophila DNA polymerase epsilon and DREF, a regulatory factor for DNA replication-related genes. Using these antibodies together with those for DNA polymerase alpha and proliferating cell nuclear antigen (PCNA), we examined expression patterns and sub-cellular distributions of these proteins during Drosophila development. DNA polymerase alpha, epsilon and PCNA proteins were maternally stored in unfertilized eggs and maintained at high levels during embryogenesis. With distinct nuclear localization, proteins were observed in embryos at interphase stages throughout the 13 nuclear division cycles, suggesting that they all participate in rapid nuclear DNA replication during these cycles. In contrast, maternal storage of a DREF protein was relatively low and its level increased throughout embryogenesis. Strong nuclear staining with the anti-DREF antibody was not observed until the nuclear division cycle 8. Immunostaining of various larval tissues from transgenic flies carrying the PCNA gene promoter-lacZ fusion gene revealed co-expression of DREF, PCNA and lacZ, suggesting that DREF regulates the expression of PCNA gene in these tissues. In addition, we detected a relatively high level of DREF in adult males as well as females. Since DNA polymerase alpha, epsilon and PCNA are hardly detectable in adult males, DREF very likely regulates genes other than those closely linked to DNA replication in adult males.

Animals↗

PubMed1995

beta-Alanyl-L-histidinato zinc and bone resorption.

1. beta-Alanyl-L-histidinato zinc (AHZ), in which zinc is chelated to beta-alanyl-L-histidine, is a new zinc compound. beta-Alanyl-L-histidine can uniquely chelated zinc ion in various essential trace metals. More recently, it has been demonstrated that this compound has more intensive effect than zinc sulfate on bone metabolism, suggesting a role as pharmacological tool in osteoporosis. This review describes mainly the action of AHZ on bone resorption as summarized in the following. 2. The prolonged oral administration of AHZ (10-100 mg/kg/day) can completely prevent bone loss in the femur of ovariectomized rats, indicating the preventive effect of AHZ on bone resorption in vivo. 3. The decrease in bone calcium content induced by various bone resorbing factors was completely inhibited by the presence of AHZ (10(-6)-10(-4) M) in bone tissue culture system in vitro. 4. Many bone resorbing agents can stimulate the formation (differentiation) of osteoclasts from marrow cells. AHZ (10(-6)-10(-4) M) clearly inhibited osteoclast-like cell formation in mouse marrow culture in vitro. 5. AHZ may act on the process of parathyroid hormone-induced protein kinase C activation which is involved in Ca(2+)-signaling in osteoclastic cells.

Animals↗

PubMed1995

Efficacy of intraportal injection of anti-ICAM-1 monoclonal antibody against liver cell injury following warm ischemia in the rat.

BACKGROUND: Increased expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte-function-associated antigen-1 (LFA-1) has been reported to play a major role in reperfusion injury after ischemia. In the present study we tested the effects of anti-rat-ICAM-1 monoclonal antibody (1A29) on partial-liver warm ischemia in rats. METHODS: Histological changes and expression of ICAM-1 and LFA-1 were investigated in rat partial-liver warm ischemia, performed by clamping hepatic hilar vessels distributing to the right lateral lobe for 30, 45, and 60 minutes. In a second study, the effects of intraportal 1A29 injection after 60 minutes of warm ischemia in the rat were examined histologically. In both studies, the liver tissue was removed for analysis 48 hours after clamping. RESULTS: Reperfusion after 60 minutes of warm ischemia induced histological liver injury and strong expression of ICAM-1 and LFA-1, although 30 and 45 minutes of ischemia did not provoke either histological damages or the expression of ICAM-1 and LFA-1. Intraportal injection of 1A29 after 60 minutes of warm ischemia clearly suppressed liver cell injury histologically. CONCLUSION: Intraportal injection of 1A29 prevented the histological inflammation of an ischemic liver and may be useful in liver surgery or liver transplantation, because high concentrations can reach the target organ and nonspecific immunosuppression in other tissues and organs can be decreased.

Animals↗

PubMed1995

Prevention of recurrent bleeding from gastric ulcer with a nonbleeding visible vessel by endoscopic injection of absolute ethanol: a prospective, controlled trial.

We performed a prospective, randomized trial to assess the efficacy of endoscopic injection therapy with absolute ethanol in preventing recurrent bleeding in patients with nonbleeding visible vessels in gastric ulcers. During the period of 1990 to 1993, 62 patients who bled were found to have gastric ulcers with nonbleeding visible vessels; all of them were enrolled for this trial. The 62 patients were randomly divided into two groups, which were comparable at entry. In group I (33 patients), we performed endoscopic injection therapy with absolute ethanol. In group II (29 patients), we sprayed the ulcers with 0.1% epinephrine and thrombin. Endoscopic injection therapy with ethanol was performed at the second endoscopy in the patients in both groups who had recurrent bleeding. Among the 33 patients in group I, 4 patients (12.1%) rebled after the initial ethanol injection therapy, whereas 10 of 29 patients (34.5%) rebled in the control group (p < .05). No patients in group I required surgical intervention, and ultimate hemostasis was achieved in all 33 group I patients (100%), indicating that endoscopic ethanol injection therapy achieves ultimate hemostasis and prevents recurrent bleeding in patients with gastric ulcers and nonbleeding visible vessels.

Epinephrine↗

PubMed1995

Development of a novel luminol-related compound, 3-propyl-7,8-dihydropyridazino-[4,5-g]quinoxaline-2,6,9(1H)- trione, and its application to hydrogen peroxide and serum glucose assays.

Manual and flow injection methods with chemiluminescence detection were developed for the determination of hydrogen peroxide (H2O2) using a novel luminol-related compound, 3-propyl-7,8-dihydropyridazino[4,5-g]quinoxaline-2,6,9(1H)-trione (PDIQ), having a higher efficiency than luminol. The methods are based on the chemiluminescence produced by the reaction of H2O2 with PDIQ in the presence of microperoxidase in alkaline media. Detection limits for manual and flow injection methods are 13 pmol per 100 microliter of test solution and 1.3 pmol per 100 microliter injection volume, respectively, at a ratio of chemiluminescence intensities (or peak heights) of test to blank of 2. The manual method was applied to the determination of glucose in human serum. The method correlated well with the conventional spectrophotometric method (4 = 0.998).

Blood Glucose↗

PubMed1995

Time course of hypertrophic adaptations of the anterior latissimus dorsi muscle to stretch overload in aged Japanese quail.

The purpose of this study was to determine if aged Japanese quail demonstrated an altered time course of change in the morphology of the anterior latissimus dorsi (ALD) muscle during the first two weeks of hypertrophy induced by stretch overload. The left wing of adult (12 weeks of age) and aged (90 weeks of age) birds were weighted with 10% of their body weight; the right wing served as the intra-animal control. Thirteen to sixteen birds from each age group were killed after 7 and 14 days of stretch overload. Total fiber number was quantified by counting all the fibers in a transverse section from the mid-belly of the ALD muscle. The aged ALD retained the ability to increase the mass and total fiber number of the stretched ALD after 7 (82%, 16%) and 14 (102%, 19%) days of stretch overload. However, there was a main effect of age on the capacity to increase muscle mass and total fiber number after stretch overload. These results suggest that aging diminishes the increase and alters the time course of adaptation in fiber number and myofibrillar mass of the stretch overloaded ALD during the first two weeks of stretch overload.

Adaptation, Physiological↗

PubMed1995

An X-ray diffraction study on a single frog skinned muscle fiber in the presence of vanadate.

Using a technique to obtain a detailed X-ray diffraction pattern from a single frog skinned muscle fiber with synchrotron radiation and an imaging plate, we studied the arrangement of myosin heads to which ADP and vanadate are bound. The presence of 1 mM vanadate during contraction caused trapping of ADP and vanadate on the myosin head. Both in the presence and absence of Ca2+, the intensities of the equatorial reflections indicated that most of the heads with ADP and vanadate were located close to the backbone of the thick filament. The presence of the first myosin layer-line at 43 nm-1 also suggested that the heads formed a helix around the shaft of the thick filament. Weak intensity of actin layer-lines suggested that the myosin heads were detached from the thin filament. The results suggest that the myosin-ADP-vanadate complex has a weak affinity toward actin regardless of the state of the regulatory system on the thin filament.

Adenosine Diphosphate↗

PubMed1995

Determination of various cytokines and type III procollagen aminopeptide levels in bronchoalveolar lavage fluid of the patients with pulmonary fibrosis: inverse correlation between type III procollagen aminopeptide and interferon-gamma in progressive patients.

We measured levels of cytokines and type III procollagen aminopeptides (procollagen III peptides) in bronchoalveolar lavage fluid obtained from 20 patients with stable pulmonary fibrosis (PF) and seven patients with progressive PF, and nine control subjects to determine the role of cytokines in the development of PF. Procollagen III peptide levels were markedly increased in progressive PF patients. Tumour necrosis factor-alpha, interleukin-6, transforming growth factor-beta and interferon-gamma (IFN-gamma) levels were elevated in both PF patients as compared with controls, with a tendency of higher levels in progressive patients, whereas interleukin-1 beta (IL-1 beta) level was decreased in both PF patients. When the correlation between procollagen III peptide and various cytokine levels was analysed the only significant correlation was inversely between procollagen III peptide and IFN-gamma in progressive PF patients. These results indicated that although multiple cytokines may be involved in the development of PF, the negative role of IFN-gamma in active collagen synthesis could be also important.

Adult↗

PubMed1995

Changes in epidermal growth factor receptor and the levels of its ligands during menstrual cycle in human endometrium.

We examined menstrual cycle-dependent changes in the expression of human endometrial epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), and epidermal growth factor receptor (EGFR) and their mRNA using immunoblot analysis, 125I-EGF binding, and competitive reverse transcription and polymerase chain reaction (RT-PCR). We also studied their localization in the endometrial tissue by immunohistochemistry. Endometrial samples were obtained at three stages of menstruation: the early follicular stage, which exhibits low serum estradiol (E2) and progesterone (P) levels; the late follicular stage, which exhibits high E2 and low P levels; and the luteal stage, which exhibits high E2 and P levels. Immunohistochemical examination showed that EGF, TGF alpha, and EGFR were localized to the endometrial epithelium. Immunoblot analysis revealed that endometrial EGF, TGF alpha, and EGFR levels were significantly (p < 0.01) increased at the late follicular and luteal stages compared to the early follicular stage. 125I-EGF-specific binding levels at the late follicular and luteal stages were significantly (p < 0.01) higher than at the early follicular stage, consistent with the results of immunoblot analysis. Competitive RT-PCR revealed that EGF, TGF alpha, and EGFR mRNA levels were significantly (p < 0.01) higher at the late follicular and luteal stages than at the early follicular stage. Changes in EGF, TGF alpha, and EGFR mRNA levels were consistent with changes in protein levels. These findings suggest that synthesis and expression of human endometrial EGF, TGF alpha, and EGFR vary with the stage of the menstrual cycle and that their expression in the human endometrium is associated with the increase in the serum E2 but not with the increase in P levels.

Binding, Competitive↗

PubMed1995

Mouse growth hormone-releasing factor secretion is activated by inhibin and inhibited by activin in placenta.

We investigated the effects of activin and inhibin on the regulation of mouse growth hormone-releasing factor (mGHRF) secretion by primary placental cells harvested at Day 12 of pregnancy. Activin-A, an activator of FSH secretion, inhibited mGHRF secretion. In contrast, inhibin, an inhibitor of FSH secretion, activated mGHRF secretion. The lowest concentrations of activin-A and inhibin that significantly affected mGHRF secretion were 2 nM. Follistatin, a binding protein of activin, completely eliminated the ability of activin to inhibit mGHRF secretion. The steady-state level of mGHRF mRNA, as assessed by Northern analysis, was reduced by incubation of placental cells with activin-A. All activin and inhibin subunit mRNAs were expressed in mouse placenta, and their expressions increased during gestation. These findings suggest that activin and inhibin have opposite effects on mGHRF secretion as compared with FSH secretion and that they regulate mGHRF secretion in an autocrine or paracrine manner in the mouse placenta in vivo.

Activins↗

PubMed1995

Posttranscriptional inhibition of mouse placental lactogen-II secretion by transforming growth factor beta 1: synergistic effects with epidermal growth factor and interleukin-6.

We studied the effect of transforming growth factor beta 1 (TGF beta 1) on mouse placental lactogen (mPL)-I and mPL-II secretion by primary cultures of placental cells from Days 7, 9, and 12 of pregnancy. We also studied the effects of co-incubation of epidermal growth factor (EGF) or interleukin-6 (IL-6) with TGF beta 1 on mPL-I and mPL-II secretion. TGF beta 1 at 10 ng/ml did not affect mPL-I secretion by cells from Days 7 or 9 of pregnancy or mPL-II secretion by cells from Day 7 of pregnancy but significantly inhibited mPL-II secretion by cells from Days 9 or 12 of pregnancy. The lowest concentration of TGF beta 1 that significantly inhibited mPL-II secretion by cells from Days 9 or 12 of pregnancy was 1 ng/ml. Immunocytochemistry for mPL-II indicated that treatment of placental cells from Day 12 of pregnancy with 10 ng/ml TGF beta 1 significantly reduced the number of mPL-II-containing cells. Inhibition of mPL-II secretion by TGF beta 1 was eliminated completely by addition of an anti-TGF beta 1 antibody. Northern analysis showed that steady state levels of mPL-II mRNA were not reduced by incubation of placental cells from Day 12 of pregnancy with 10 ng/ml TGF beta 1 for 5 days. EGF at 10 ng/ml significantly inhibited mPL-II secretion by cells from Day 7 of pregnancy, and addition of 10 ng/ml TGF beta 1, which did not itself inhibit mPL-II secretion by those cells, enhanced the inhibition by EGF of mPL-II secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Cytokines that use gp130 as a signal transducer stimulate mouse placental lactogen-I (mPL-I) but inhibit mPL-II production in vitro.

Interleukin-11 (IL-11), leukemia inhibitory factor (LIF), and oncostatin M (OM), all of which use gp130 as a signal transducer, significantly inhibited mouse placental lactogen-II (mPL-II) secretion by cultured placental cells from Days 7, 9, and 12 of pregnancy. These cytokines significantly stimulated mPL-I secretion by cells from Day 9, but not Day 7, of pregnancy. An antibody to LIF completely blocked the stimulatory and inhibitory effects of LIF on mPL-I and mPL-II secretion, respectively. LIF and OM decreased the abundance of mPL-II mRNA in placental cells. Double immunocytochemistry for mPL-I and mPL-II indicated that LIF, OM, and IL-11 significantly increased the number of giant cells containing only mPL-I or both mPL-I and mPL-II but decreased the number of giant cells containing only mPL-II. IL-6, which also uses gp130 as a signal transducer, inhibits mPL-II secretion only after midpregnancy; however, addition of soluble IL-6 receptor (sIL-6R) together with IL-6 resulted in a significant inhibition of mPL-II secretion before midpregnancy. Treatment of cells from Day 12 of pregnancy with IL-6 during the first 2 days of culture resulted in significant inhibition of mPL-II secretion by the third day of culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Expression of interleukin-5 receptors on acute myeloid leukaemia cells: association with immunophenotype and karyotype.

Eosinophilia sometimes occurs in acute myeloid leukaemia (AML) and several laboratories have reported that cells with the t(8;21) or structural abnormalities of chromosome 16 can proliferate and differentiate to eosinophils in the presence of IL-5 in vitro. However, cases without these chromosomal abnormalities can also have eosinophilia. We investigated the association between the expression of IL-5 receptor (IL-5R) gene, karyotype and phenotype in 35 patients with AML. All cases expressed the IL-3R but the IL-5R gene was expressed predominantly in leukaemic cells with either t(8;21) or CD4-positive immunophenotype and was associated with the presence of eosinophilia.

Acute Disease↗

PubMed1995

Multilocular lymphoepithelial cyst in the thyroid accompanied with a minute thyroid carcinoma.

An aggregate (17 x 13 mm) of a few small cysts was incidentally found in the left lobe of the thyroid of a 42 year old man. The inner surface of the cysts was lined by stratified cuboidal to columnar epithelium, which showed occasional ciliation and keratinization. The cysts were densely surrounded by follicular lymphoid tissue. The lesion was designated as a multilocular lymphoepithelial cyst. Directly adjacent to the cyst-aggregate a minute focus of papillary thyroid carcinoma (6 x 6 mm) existed. Tubular or papillary clusters of cancer cells were occasionally contiguous to the lining epithelium, which had penetrated through the lymphoid mantle of the cysts. Histological features of the lesion in the thyroid suggested an origin of the cysts from the developmental rest of the branchial pouch; probably from the ultimobranchial body remnant.

Adult↗

PubMed1995

Proliferation and differentiation of myelodysplastic CD34+ cells in serum-free medium: II. Response to combined colony-stimulating factors.

To investigate the role of colony stimulating factors (CSFs) in the proliferation and differentiation of progenitor cells from myelodysplastic syndromes (MDS), marrow progenitor cells from 18 MDS patients were highly purified using CD34 monoclonal antibody and immunomagnetic microspheres (MDS CD34+ cells). These cells were cultured in serum-free medium with various combinations of five colony stimulating factors (CSFs): recombinant human interleukin-3 (rIL-3), granulocyte/macrophage-CSF (rGM-CSF), granulocyte-CSF (rG-CSF), macrophage-CSF (rM-CSF), and erythropoietin (rEP). Among the tested CSFs, such as rM-CSF, rG-CSF, rGM-CSF and rIL-3, a combination of the first three CSFs was the most effective stimulus for the proliferation of non-erythroid MDS progenitor cells. An increase of undifferentiated "blast" cell colonies in 5/18 MDS patients occurred and these 5 patients belonged to the high-risk group. In the presence of these three CSFs, rIL-3 had no effect on the proliferation and differentiation of MDS CD34+ cells; however, IL-3 was efficient for the proliferation of MDS CD34+ cells to the erythroid lineage. rGM-CSF or rIL-3 alone did not efficiently support proliferation and differentiation of CD34+ cells. M-CSF is present in normal human serum at a concentration of 550 +/- 110 U/ml, a concentration exceeding that used in this study (100 U/ml). Therefore, in vivo administration of G-CSF combined with GM-CSF to MDS patients may be one of the most effective CSF combinations for proliferation of MDS progenitor cells to the non-erythroid lineage. However, the effect on the capacity for differentiation was minimal, especially in patients belonging to the high-risk group.

Adult↗