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Biomedical subjects

M Yamaguchi

Publications and source records attributed to M Yamaguchi.

At least 955 records · Page 53Linked to original sources
PubMed1994

Effects of DNA polymerase beta gene over-expressed in transgenic Drosophila on DNA repair and recombination.

DNA polymerase beta (pol beta) cDNA of rat fused to an enhancer-promoter region plus a poly(A) signal sequence of actin 5C gene of Drosophila (abbreviated pol beta) was transferred to the Drosophila genome. Three of four constructed transgenic strains possessing transgene pol beta on different chromosomes were studied. Levels of the pol beta transcript and those of the polymerization activity of pol beta were markedly elevated in cultured cells transfected with pol beta-bearing vectors as well as in embryos of the transgenic strains. The popular idea that DNA polymerase beta participates in DNA repair was not supported by the observation that a pair of a normal and a pol beta strain, and the other pair of a mei-9 mei-41 (DNA-repair deficient double mutations) strain and a pol beta mei-9 mei-41 strain, showed no difference in survival within each pair after treatment with ultraviolet light, methylmethane sulfonate and mitomycin C. The other idea that DNA polymerase beta participates in recombination was supported by the findings that spontaneous frequency of recombination, either meiotic or mitotic, is significantly higher in a transgenic pol beta strain than in a non-transgenic strain. The enhanced recombination frequency in the pol beta strain may, however, reflect an indirect effect of over-produced pol beta proteins on chromosomal stability. Whatever the direct effect of rat pol beta is, the transgenic pol beta flies will be useful for study of the physiological role of pol beta and the mechanism of recombination.

Animals↗
PubMed1994

Malonylated anthocyanins from bulbs of red onion, Allium cepa L.

Four cyanidin-based anthocyanins (1-4) were isolated from the red onion, Allium cepa L. Pigments 1 and 3 were identified as cyanidin 3-glucoside (Cy 3-Glc) and 3-malonylglucoside (Cy 3-MaGlc), respectively, by cochromatography with standard pigments. Anthocyanins 2 and 4 were respectively determined as cyanidin 3-laminaribioside (Cy 3-Lam) and 3-malonyllaminaribioside (Cy 3-MaLam), a new anthocyanin, mainly by NMR techniques. Malonylated anthocyanins 3 and 4 were found for the first time in red onions.

Allium↗
PubMed1994

Serum immunoreactive inhibin levels in polycystic ovarian disease (PCOD) and hypogonadotropic amenorrhea.

To evaluate the physiological significance of inhibin in various types of amenorrhea, serum immunoreactive (IR)-inhibin levels were measured and compared with those in normal cycling women. Amenorrheic women were as follows: (1) 23 women with PCOD, 11 women with hypogonadotropic amenorrhea (HA, n = 23) and 11 women with regular menstrual cycles. Women with HA were further divided into 2 groups according to the presence or absence of withdrawal bleeding (WDB) after progesterone administration. HA with WDB was categorized as HA1, while HA without as HA 2. Serum IR-inhibin levels in women with PCOD were significantly higher than those in HA 2 and normal women at days 2 to 5 from the onset of menstruation and significantly lower than those in normal women in the mid-luteal phase. A significant positive correlation was obtained between IR-inhibin and FSH in HA 2 (r = 0.681) and HA 1 (r = 0.658), but no significant correlation between these two hormones in PCOD and normal women. These results indicated that basal IR-inhibin levels vary with types of amenorrhea. High IR-inhibin levels in PCOD patients suggest that inhibin plays a part in the discordant gonadotropin secretion in these patients.

Adult↗
PubMed1994

Changes in serum immunoreactive inhibin during ovulation induction in women with amenorrhea.

Changes in serum immunoreactive (IR)-inhibin were measured by RIA in two studies, in order to elucidate, firstly whether the pattern of IR-inhibin secretion is similar to that of estradiol (E2), and secondly, whether inhibin suppresses endogenous FSH release. Study 1: Purified urinary FSH (pFSH) or human menopausal gonadotropin (hMG) were daily injected intramuscularly into women with hypogonadotropic amenorrhea at 12 to 14 week intervals. PFSH and hMG stimulated IR-inhibin release in a similar fashion in the ovulatory cycles, but the increase in estradiol (E2) during pFSH administration was delayed and lower than that during the hMG cycles. This suggests that E2 and IR-inhibin are secreted independently from the granulosa cells. Study 2: Ovulation induction was performed in 18 cycles of 9 women with polycystic ovarian disease (PCOD) by the step-down administration of pFSH. The serum FSH concentration in cycles with premature LH release increased even after the dose of pFSH was reduced, and were significantly higher than those of cycles without premature LH release. It was also found that the serum IR-inhibin concentration in cycles with the premature LH release was 2 to 4 times as high as in cycles without premature LH release. This suggests that IR-inhibin does not suppress endogenous FSH release associated with premature LH release.

Adult↗
PubMed1994

Monoamine oxidase activity in rat organs during pregnancy.

To elucidate the involvement of MAO activity in rat pregnancy, female rats exhibiting at least 3 consecutive 4-day estrous cycles were used. The day of sperm-positive smears was designated as day 0 of pregnancy. The rats were sacrificed on day 2 of diestrus (diestrus-2) and days 7, 14 and 21 of gestation. The organs were collected and weighted, and mitochondrial fractions were prepared for MAO analysis with kynuramine dihydrobromide as substrate. Specific activity (pmol/mg of protein/min) in the ovary is significantly lower in rats on diestrus-2 (792 +/- 127) (mean +/- S.D.) than on day 14 (1,038 +/- 140) and day 21 (1,580 +/- 61) of pregnancy. However, the levels of MAO activity in the uterus of rats on diestrus-2 (899 +/- 266) is higher than on day 21 (570 +/- 80) of pregnancy. The MAO activity in the placenta on day 21 (644 +/- 82) was higher than day 14 (356 +/- 88) of pregnancy. Total MAO activity per organ (nmol/min) of ovary on day 21 (27.2 +/- 5.2) is higher than on diestrus-2 (8.7 +/- 3.0) and on day 14 (14.2 +/- 3.6). Our results suggest that MAO activity in rat reproductive organs such as uterus, ovary, and placenta might fluctuate significantly near term, in correlation with steroid levels, tissue catecholamine contents and so on, in order to maintain pregnancy.

Animals↗
PubMed1994

Expression of growth hormone-binding protein with a hydrophilic carboxyl terminus by the mouse placenta: studies in vivo and in vitro.

GH-binding protein (GHBP) or GH receptor is present in numerous extrahepatic tissues in the rodent. From mid- to late gestation in the mouse, the maternal serum concentration of GHBP increases 30- to 50-fold. We have investigated whether the placenta might synthesize GHBP and potentially contribute to this increase. RNA was isolated from placentas and subjected to Northern analysis using a cDNA probe to the shared region of GHBP and GH receptor-encoding mRNAs. From day 8 to day 18 of gestation, the GHBP-encoding mRNA (1.4 kb) increased 45-fold in quantity. The GH receptor-encoding mRNA (4.2 kb) increased sixfold by day 14 and then remained steady until day 18. These changes which were not co-ordinated parallel reported changes in the steady-state concentrations of 1.4 and 4.2 kb mRNAs in maternal liver, suggesting shared regulatory factors. Extracts of freshly isolated trophoblasts were assayed for GHBP with a radioimmunoassay specific for GHBP with a hydrophilic carboxyl terminus. The cytosolic content of immunoreactive GHBP increased fourfold from mid- to late gestation. Trophoblasts were isolated from placentas and cultured for 2 days on collagen gels in defined medium. Cultured cells were at least 90% viable and secreted mouse placental lactogen-II (mPL-II). Immunocytochemistry was carried out simultaneously on cells cultured from day 7 to day 17 of gestation using a monoclonal antibody (MAb 4.3), which recognizes the hydrophilic C-terminus of GHBP. Cell-localized GHBP was present in trophoblasts cultured for 2 days, but GHBP was not detectable by radioimmunoassay or by immunoprecipitation in concentrated culture media from cultures treated with 100 ng mouse GH/ml or 100 ng mPL-II/ml or from untreated cultures. RNA was isolated from cells cultured in an identical manner to those analysed by immunocytochemistry. Three GH receptor/GHBP mRNA species of 8, 4.2 and 1.4 kb were observed. The quantity of 4.2 and 1.4 kb mRNAs did not change significantly in cultures from day 7 to day 15 of gestation but, in cultures from day 17 of gestation, the amount of 1.4 kb mRNA dropped significantly, while that of the 4.2 kb mRNA remained unchanged. GHBP- and GH receptor-encoding mRNAs are not co-ordinately regulated in vivo or in vitro. Although mPL-II was secreted into the medium by cultured trophoblasts, secretion of GHBP could not be detected. The culture medium may not contain the specific factors required for secretion of placental GHBP, or placental GHBP may not be destined for secretion.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

Selective inhibition of mouse placental lactogen II secretion by tumour necrosis factor-alpha.

The placental members of the prolactin-GH-placental lactogen (PL) gene family of the mouse include mPL-I, mPL-II, proliferin (PLF) and proliferin-related protein (PRP). The aim of the present study was to assess the effects of tumour necrosis factor-alpha (TNF-alpha) on the secretion of these proteins in primary cultures of placental cells from days 7, 9 and 12 of pregnancy. The effects of epidermal growth factor (EGF) on the secretion of PLF and PRP were also determined. EGF has previously been shown to stimulate mPL-I and inhibit mPL-II secretion. Incubation of placental cells from day 7 of pregnancy for 5 days with 10 nmol human (h)TNF-alpha/l did not affect the mPL-II concentration of the medium, but similar treatment of cells from days 9 or 12 of pregnancy resulted in a significant reduction in the mPL-II concentration of the medium by the second or third day of culture. The intracellular concentration of mPL-II, the number of cells that released mPL-II as assessed by reverse haemolytic plaque assay, and steady-state levels of mPL-II mRNA as assessed by Northern analysis were also reduced by hTNF-alpha treatment. The lowest concentration of hTNF-alpha that significantly inhibited mPL-II secretion by cells from day 12 of pregnancy was 0.01 nmol/l. hTNF-alpha treatment did not affect the secretion of mPL-I, PLF or PRP, as assessed by the concentrations of these proteins in the medium during a 5-day incubation. Incubation of the cells with 20 ng EGF/ml also did not affect the PLF or PRP concentration of the medium during 5 days of culture. To determine whether the effect of hTNF-alpha on mPL-II secretion was mediated by interleukin-6 (IL-6), the IL-6 concentration of the medium of control and hTNF-alpha-treated cells was determined. Bioactive and immunoreactive IL-6 could not be detected in medium from either treatment group. The presence of binding sites for hTNF-alpha was assessed in cells from day 12 of pregnancy. Scatchard analysis detected a single class of binding sites having a Kd of 1.61 +/- 0.34 nmol/l, with about 1350 sites per cell. The results of this study demonstrate that hTNF-alpha inhibits the secretion of mPL-II by placental cells from days 9 and 12 of pregnancy, suggesting that TNF-alpha may be one of the factors that regulate the production of this hormone in vivo.

Animals↗
PubMed1994

Inhibition of collagen production by traditional Chinese herbal medicine in scleroderma fibroblast cultures.

The in vitro effect of one traditional Chinese herbal medicine (Japanese name: "Keishi-bukuryo-gan"), which has been empirically used in scleroderma patients in China and Japan, on collagen production in fibroblast cultures was studied. Fibroblasts from 3 scleroderma patients and 2 normal controls were incubated with various concentrations of "Keishi-bukuryo-gan" and collagen production was then determined by a radiochemical method. "Keishi-bukuryo-gan" significantly and selectively inhibited collagen synthesis in a dose-dependent manner, with a tendency of a stronger effect on scleroderma fibroblasts than control cells. The results may explain the clinical usefulness of this medicine, and it may become a promising new agent for the treatment of scleroderma.

Adult↗
PubMed1994

A human T-cell lymphotropic virus type I carrier with temporal arteritis terminating in acute myelogenous leukemia.

A human T-cell lymphotropic virus type I (HTLV-I) carrier with temporal arteritis (TA) in whom acute myelogenous leukemia (AML) developed 1 year after successful treatment of the autoimmune disease is described. This case suggested that the induction of immunodeficiency by infection with HTLV-I may be related to the development of the autoimmune disease and malignancy.

Aged↗
PubMed1994

Trilineage response to rhG-CSF with subsequent clonal hematopoiesis in a patient with severe bone marrow aplasia.

We treated a patient with severe aplastic anemia with long-term administration of recombinant human granulocyte-colony stimulating factor (rhG-CSF). When a trilineage response of hematopoiesis was obtained after the first treatment, a chromosomal change [45XX, -7] was observed in 20 of the 20 metaphases examined. Later, we were able to show a monoclonal X inactivation pattern in the phosphoglycerate kinase (PGK) gene in the peripheral blood polymorphonuclear leukocytes and mononuclear cells, indicating the presence of clonal hematopoiesis regardless of the disappearance of the karyotype abnormality. We suggest that it is important to pay close attention to the appearance of clonal hematopoiesis during the administration of G-CSF to patients with idiopathic severe bone marrow aplasia.

Adult↗
PubMed1994

[Endocrine chemotherapy for prostatic cancer].

We carried out a randomized joint study on endocrine therapy and endocrine chemotherapy for prostatic cancer at our department and 17 affiliated institutions. Of 80 patients entered, 39 patients were treated with chlormadinone acetate alone (group A) and 41 patients were treated with chlormadinone acetate in combination with UFT (group B). After excluding 10 inappropriate patients, Stage C was observed in 14 patients in group A and 13 in group B, and stage D in 20 patients in group A and 23 in group B. Side effects were observed in 8.8% (3/34) in group A and 22.2% (8/30) in group B without a significant difference. The anti-tumor effects (response rate) and clinical effects with respect to each item did not significantly differ between the two groups. The non-recurrence rate and survival rate were significantly higher in group B than in group A. These findings suggest the usefulness of endocrine chemotherapy using UFT.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Transitional changes in immunophenotypic subpopulations of human peripheral blood CD34+ cells expanded in vitro.

We determined the appropriate incubation period to expand human peripheral blood (PB) CD34+ cells for clinical application and the role of recombinant human (rh) interleukin-3 (rhIL-3) in the expansion and differentiation of these cells. The cells were purified up to 40 +/- 16% and transitional changes in immunophenotypic subpopulations in suspension culture were examined following stimulation with three different combinations of rh colony-stimulating factors (rhCSFs): 1) rhIL-3 alone, 2) rhIL-6, rhSCF, rhG-CSF, plus rhGM-CSF, and 3) the four CSFs plus rhIL-3. With all three CSF combinations, the total cells increased continuously after day 5 until day 14, and a combination of the five CSFs always gave rise to the highest number of total cells. Immunophenotypic analysis of the expanded cells showed that with all three CSF combinations CD34+ cells reached a maximal rate on day 5 and then decreased in an inverse correlation between the logarithm of CD34 positive rate and the duration of suspension culture. The maximum expansion of CD34+ cells and PB progenitor cells (PBPC) with rhIL-3 alone, the four CSFs, or the five CSFs was observed on day 5, 10, or 7, respectively. The combination of the five CSFs was identified as the most potent stimulus for expansion of PBPC and CD34+ cells, as it increased non-erythroid PBPC 89 +/- 69-fold, with a range of 24 to 204-fold on day 7. However, differences in the expansion rate of these cells on days 5, 7, and 10 were not statistically significant. The majority of purified CD34+ cells coexpressed CD38 (91 +/- 3%) but were negative for CD33 (85 +/- 4%), and one-half coexpressed CD13. With all three combinations of CSFs, the mature CD34+ cells that coexpressed CD38, CD33, or CD13 expanded in parallel with the total CD34+ cells, while an increase in relatively immature CD34+ cells, which do not express CD38, CD33, or CD13, was only statistically significant with the five CSFs. Thus, rhIL-3 played a critical role when combined with the four CSFs by increasing both mature and immature CD34+ cells.

Adult↗
PubMed1994

[Capsaicin-induced cough. Tachyphylaxis and the effect of anaesthesia on the pharynx].

We examined the reproducibility of capsaicin-induced cough thresholds and the influence of pharynx anaesthesia used to treat the cough. We performed cough threshold tests on ten patients with bronchial asthma and ten patients with chronic cough. The lowest level of capsaicin-induced cough threshold was defined as ten coughs. Tachyphylaxis in cough thresholds was examined three times at intervals of 30 minutes and 120 minutes after the initial test. We measured cough thresholds before and after pharynx anaesthesia with xylocainbiscus. There was no change in cough thresholds among the three times; nor was them any change in the thresholds before and after pharynx anaesthesia. But in five patients with acute pharyngitis, the cough thresholds after pharynx anaesthesia were greater than before. It was suggested that cough threshold tests had reproducibility 30 minutes and 120 minutes after indicating that tachyphylaxis did not exist. Furthermore it was suggested that pharynx anaesthesia influenced the cough threshold in patients with acute inflammation of the pharynx, but anesthesia had no influence on cough thresholds in patients without acute inflammation of the pharynx.

Adult↗
PubMed1994

Dynamics of hepatitis B virus core antigen in a transformed yeast cell: analysis with an inducible system.

Transformed yeast cells expressing hepatitis B virus core antigen (HBcAg) were found to accumulate abundant core particles in the same way as human hepatocytes infected with hepatitis B virus (HBV) by the present authors. We, therefore, offer a good model system for studying the dynamics of assembly of HBcAg into core particles. To investigate this problem, we have developed a transformed yeast cell in which expression of HBcAg is highly inducible by deprivation of phosphate in the culture medium. At regular intervals after induction, cells were cryo-fixed and processed for transmission electron microscopy by ultrathin sectioning. After induction, HBcAg activity rapidly increased, becoming several hundred times higher than the initial level after 25 h. The core particles first appeared in the nucleus, then in the cytoplasm, and finally in the vacuole. Core particles passing through nuclear pores from the nucleus to the cytoplasm could be seen. Core particles were either incorporated directly in the vacuole or indirectly by first forming an autophagosome. The core particles were then released into the vacuolar sap, and were digested there. Together with the previous studies, our results suggest that, in human hepatocytes, HBcAg polypeptides are synthesized in the cytoplasm, but are assembled into core particles in the nucleus. The assembled core particles are then transported from the nucleus to the cytoplasm through nuclear pores.

Cell Line, Transformed↗
PubMed1994

A serine protease in soybean seeds that acts specifically on the native alpha subunit of beta-conglycinin.

A proteolytic activity directed against the alpha subunit of beta-conglycinin was detected in resting mature seeds of the soybean [Glycine max (L.) Merrill] cultivar Keburi. The relationship between pH and activity and the effect of protease inhibitors revealed that the enzyme was a neutral/alkaline serine protease. The proteolysis of the alpha subunit of beta-conglycinin yielded a specific product with a molecular weight of about 47,000, as determined by SDS-PAGE, but the enzyme had no activity against the beta subunit. The amino acid composition, the molecular weight and the amino-terminal amino acid sequence of the proteolytic product revealed that the action of the enzyme on the alpha subunit was specific, with cleavage occurring only at the R126-R127 peptide bond of the alpha subunit. These characteristics of the protease indicate that the enzyme is a novel protease that has not previously been recognized in soybean seeds.

Amino Acid Sequence↗
PubMed1994

[Effect of combination therapy with disodium cromoglycate (DSCG) and Ozagrel on non-atopic asthmatics].

Ozagrel (OKY-046), a selective inhibitor of thromboxane biosynthesis has been reported to reduce airway hyperresponsiveness in asthmatics. DSCG has been widely used for atopic, but not for non-atopic asthmatics. We evaluated the additive effect of combination therapy with DSCG and Ozagrel on nonatopic asthmatics. Fourteen asthmatics were divided into two groups. The patients in the O-D group were initially treated with Ozagrel (400 mg/day) for 4 weeks, and then DSCG (8 mg/day) was added for another 4 weeks. The patients in D-O group were initially treated with DSCG (8 mg/day), and then Ozagrel (400 mg/day) was added for 4 more weeks. TXB2, PGF2 alpha, PGE2, 6-keto-PGF1 alpha in sputum and 11-dehydro TXB2 in urine were measured before and after 4th and 8th weeks of therapy. Ozagrel decreased the metabolites of thromboxane and PGF2 alpha in sputum and urine. PGE2 in sputum tended to be increased by Ozagrel. DSCG did not affect mediators in sputum. Combination therapy with Ozagrel and DSCG showed the additive effect to single use on attack score and PF in non-atopic asthmatics.

Adult↗
PubMed1994

Chronic pharmacological activities of the novel anxiolytic beta-carboline abecarnil in rats.

Abecarnil, a novel beta-carboline anxiolytic, has been shown to possess potent anxiolytic and anticonvulsant activities with weak or no sedative and ataxic effects in relevant animal models. In the present study, anxiolytic, anticonvulsant and amnesic effects of abecarnil after single and repeated treatments in rats were compared with those of diazepam. Both abecarnil (0.52-10 mg/kg, p.o.) and diazepam (20 and 50 mg/kg, p.o.) exhibited significant anticonflict effects in the water-lick test. Neither abecarnil (5 mg/kg, p.o.) nor diazepam (50 mg/kg, p.o.) produced any tolerance to anticonflict effects after 14 days of repeated treatment. Both abecarnil (5-50 mg/kg, p.o.) and diazepam (20 and 50 mg/kg, p.o.) exhibited significant anticonvulsant effects against pentylenetetrazol-induced seizure. The anticonvulsant effects of abecarnil (5 mg/kg, p.o.) were not attenuated during 14 days of repeated treatment, but diazepam (20 and 50 mg/kg, p.o.) produced tolerance to anticonvulsant effects after 5 days of repeated treatment. In the three-panel runway task, abecarnil at 5 mg/kg, p.o. impaired only working memory, but diazepam at 20 mg/kg, p.o. impaired working memory and at 50 mg/kg, p.o. markedly impaired reference and working memories. The amnesic effects of abecarnil disappeared rapidly within 2 to 3 days of repeated treatment, whereas that of diazepam decreased rapidly but persisted during 14 days of repeated treatment. Thus, chronic abecarnil was found to exhibit persistent anxiolytic and anticonvulsant effects without any amnesic effects, in contrast to chronic diazepam.

Animals↗