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Biomedical subjects

Yuji Murata

Publications and source records attributed to Yuji Murata.

At least 73 records · Page 4Linked to original sources
PubMed2004

Effects of 4-hydroxy-2-nonenal, a marker of oxidative stress, on the cyclooxygenase-2 of human placenta in chorioamnionitis.

Chorioamnionitis (CAM) is one of the causes of preterm labour. A recent study has indicated that NADPH oxidase, a reactive oxygen species (ROS)-producing enzyme, is activated in CAM. CAM is thought to be closely associated with oxidative stress. We have hypothesized that oxidative stress in CAM may induce preterm labour. The purpose of this study is to examine the effect of 4-hydroxy-2-nonenal (HNE), which is a marker of oxidative stress, on human placenta during preterm labour. We initially examined the HNE-modified proteins in human placentas by immunoblotting and immunohistochemistry using anti-HNE antibody. To examine the effect of HNE on human placenta, we stimulated human placental tissue with HNE. The expressions of cyclooxygenase-2 (COX-2) mRNA and protein were observed by RT-PCR and western blot analysis respectively. Furthermore, we measured the peroxidase activity of COX-2 by COX activity assay kit. Prostaglandin E(2) (PGE(2)) in the supernatants of placental tissue was also determined by enzyme-linked immunosorbent assay. Immunoblotting and immunohistochemistry showed that the levels of HNE-modified proteins were increased in the placentas with CAM, compared to the normal placenta. HNE induced the expression of COX-2 mRNA, protein and activity in the placental tissue culture stimulated with HNE. In addition, PGE(2) was also released into the medium in a time-dependent fashion. These findings suggest that HNE-modified proteins, which were increased in the placenta with CAM, play an important role in preterm labour.

Aldehydes↗
PubMed2004

Detection of erythropoietin in human seminal plasma.

OBJECTIVE: To examine the presence of erythropoietin (EPO) in ejaculates and the association between EPO levels in seminal plasma and semen parameters. DESIGN: Retrospective analysis. SETTING: University hospital in Japan. PATIENT(S): Eighty-three infertile males and 16 volunteers with proven fertility. INTERVENTION(S): Semen was obtained by masturbation after 5 days of abstinence. Blood sample and split ejaculates of 16 volunteers with proven fertility were collected. MAIN OUTCOME MEASURE(S): Western blot analysis and enzyme-linked immunoassay in the seminal plasma and sperm parameters. RESULT(S): Western blot analysis showed that EPO protein was present in the seminal plasma. The EPO titers in the seminal plasma ranged from 1.5 mIU/mL to 45.0 mIU/mL by enzyme-linked immunoassay. There was no significant association between EPO levels and semen parameters. The first fraction of samples obtained by split ejaculation contained almost the same amount of EPO as the second fraction. CONCLUSION(S): Erythropoietin protein was constitutively present in seminal plasma. The seminal EPO originated from the prostate and seminal vesicle. No association between EPO levels in seminal plasma and sperm parameters was found in the present study.

Blotting, Western↗
PubMed2004

NF-kappaB activation at implantation window of the mouse uterus.

PROBLEM: Nuclear factor kappa B (NF-kappaB) is one candidate transcriptional modulator, which might regulate many kinds of molecules that play sequential roles at implantation in the endometrium. However, temporal and spatial activation of NF-kappaB at implantation window is unknown. METHODS: Activation of NF-kappaB in the mouse uterus was determined by electrophoretic mobility shift assays. Localization of p50 and p65, components of NF-kappaB, was analyzed by immunohistochemistry. RESULTS: NF-kappaB was activated in the proestrus and estrus phases in non-pregnant uterus. In the pregnant uterus, NF-kappaB was activated after day 1.5 post-coitum, and the activation continued during implantation period. The immunoreactivities of p50 and p65 were mainly localized in endometrial epithelium, and were weaker in endometrial stroma cells. CONCLUSION: NF-kappaB activity is dynamically regulated during the sexual cycle as well as during the implantation period in the endometrium, where the biochemical interaction between mother and conceptus first occurs.

Animals↗
PubMed2004

Expression of fractalkine in the Fallopian tube and of CX3CR1 in sperm.

BACKGROUND: Fractalkine is a CX(3)C chemokine that has chemoattractant activity for T cells, monocytes and natural killer (NK) cells. The objective of this study was 2-fold: to evaluate (i) the presence of fractalkine in the Fallopian tube and (ii) the existence of CX(3)CR1 (fractalkine receptor) in ejaculated sperm. METHODS AND RESULTS: Western blot analysis revealed that fractalkine protein was detected as a 95 kDa band in the isthmus, the ampulla and the infundibulum of the Fallopian tube. Immunohistochemistry revealed positive staining of epithelial cells in the Fallopian tube. RT-PCR demonstrated that fractalkine transcripts were expressed in all parts of the Fallopian tube. RT-PCR also revealed that CX(3)CR1-positive cells were present in the Fallopian tube. CX(3)CR1-positive cells were present in the stroma of the Fallopian tube. The villi of the ciliated cells were positively stained. To determine the function of fractalkine in the Fallopian tube, we examined whether CX(3)CR1 was present in ejaculated sperm. RT-PCR demonstrated that CX(3)CR1 transcripts were expressed in the ejaculated sperm. Immunohistochemistry demonstrated positive staining of the tail of the spermatozoa. CONCLUSIONS: The present findings suggest that fractalkine in the Fallopian tube contributes to the immunodefence mechanism during fertilization and to the sperm motion in the oviduct.

Adult↗
PubMed2004

Uterine rupture of cesarean scar related to spontaneous abortion in the first trimester.

We report the case of a 31-year-old Japanese female diagnosed by transvaginal ultrasonography to have a spontaneous uterine rupture in the first trimester. Her condition was complicated by diabetes mellitus type 1. Her previous pregnancy had resulted in an emergency cesarean section by transverse incision of the lower uterine segment with single-layer suture at 37(+4) weeks of gestation. Transvaginal ultrasonography displayed both a gestational sac located in the anterior lower uterine segment and a defect in the uterine wall located at the site of the previous cesarean delivery scar. Pelvic magnetic resonance imaging showed that the uterine muscle layer was discontinuous and the gestational sac was almost outside the uterine cavity, accompanied by mild hemorrhaging within the endometrial cavity. The defect in the lower uterine wall was round in shape and was 3 cm in diameter. Since uterine ruptures can occur during all gestational periods, it is important to pay attention to the uterine wall where any cesarean incision was previously made.

Abortion, Spontaneous↗
PubMed2004

Changes of lipocalin-type prostaglandin D synthase level during pregnancy.

AIM: Prostaglandin D (PGD), synthesized by lipocalin-type prostaglandin D synthase (L-PGDS), has marked effects on a number of biological processes, including the prevention of platelet aggregation and the relaxation of vascular smooth muscle. The aim of the study presented here was to examine the significance of L-PGDS in human pregnancy. METHODS: We measured the concentration of plasma L-PGDS in pregnant and non-pregnant women, and the concentration of L-PGDS in the umbilical cord blood, amniotic fluid and urine of newborns by enzyme-linked immunoabsorbent assay. To determine the localization of L-PGDS, we performed immunohistochemical analysis. To evaluate the usefulness of diagnosis of rupture of membranes (ROM), we determined the concentration of L-PGDS in cervicovaginal secretions. RESULTS: Pregnant women and non-pregnant women had similar L-PGDS concentrations (0.57 +/- 0.13 microg/mL vs 0.53 +/- 0.07 microg/mL). Umbilical cord blood, amniotic fluid and newborn urine contained higher L-PGDS concentrations (1.87 +/- 0.73 microg/mL, 2.62 +/- 0.86 microg/mL, 6.31 +/- 4.62 microg/mL, respectively) than maternal blood. The concentration of L-PGDS in amniotic fluid from 19 weeks onward was significantly greater than that at 15-18 weeks (3.201 +/- 0.384 microg/mL, n = 6 vs 1.735 +/- 0.477 microg/mL, n = 4; P < 0.05). Immunohistochemistry revealed that the amniotic cells of the placenta expressed L-PGDS. The sources of L-PGDS in amniotic fluid are fetus urine and amniotic cells. The concentration of L-PGDS in cervicovaginal secretions with rupture of membrane (ROM) were significantly higher than those without ROM. CONCLUSION: The measurement of L-PGDS in cervicovaginal fluid was useful in the detection of ROM during pregnancy.

Adult↗
PubMed2004

Sinusoidal heart rate pattern: Reappraisal of its definition and clinical significance.

OBJECTIVES: To address the clinical significance of sinusoidal heart rate (SHR) pattern and review its occurrence, define its characteristics, and explain its physiopathology. BACKGROUND: In 1972, Manseau et al. and Kubli et al. described an undulating wave form alternating with a flat or smooth baseline fetal heart rate (FHR) in severely affected, Rh-sensitized and dying fetuses. This FHR pattern was called 'sinusoidal' because of its sine waveform. Subsequently, Modanlou et al. described SHR pattern associated with fetal to maternal hemorrhage causing severe fetal anemia and hydrops fetalis. Both Manseau et al. and Kubli et al. stated that this particular FHR pattern, whatever its pathogenesis, was an extremely significant finding that implied severe fetal jeopardy and impending fetal death. UNDULATING FHR PATTERN: Undulating FHR pattern may be due to the following: (1) true SHR pattern; (2) drugs; (3) pre-mortem FHR pattern; (4) pseudo-SHR pattern; and (5) equivocal FHR patterns. FETAL CONDITIONS ASSOCIATED WITH SHR PATTERN: SHR pattern has been reported with the following fetal conditions: (1) severe fetal anemia of several etiologies; (2) effects of drugs, particularly narcotics; (3) fetal asphyxia/hypoxia; (4) fetal infection; (5) fetal cardiac anomalies; (6) fetal sleep cycles; and (7) sucking and rhythmic movements of fetal mouth. DEFINITION OF TRUE SHR PATTERN: Modanlou and Freeman proposed the following definition for the interpretation of true SHR pattern: (a) stable baseline FHR of 120-160 bpm; (b) amplitude of 5-15 bpm, rarely greater; (c) frequency of 2-5 cycles per minute; (d) fixed or flat short-term variability; (e) oscillation of the sinusoidal wave from above and below a baseline; and (f) no areas of normal FHR variability or reactivity. PHYSIOPATHOLOGY: Since its early recognition, the physiopathology of SHR became a matter of debate. Murata et al. noted a rise of arginine vasopressin levels in the blood of posthemorrhagic/anemic fetal lamb. Further works by the same authors revealed that with chemical or surgical vagotomy, arginine vasopressin infusion produced SHR pattern, thus providing the role of autonomic nervous system dysfunction combined with the increase in arginine vasopressin as the etiology. CONCLUSION: SHR is a rare occurrence. A true SHR is an ominous sign of fetal jeopardy needing immediate intervention. The correct diagnosis of true SHR pattern should also include fetal biophysical profile and the absence of drugs such as narcotics.

Arrhythmias, Cardiac↗
PubMed2004

Differential expression and localization of decorin in human choriodecidual membrane during preterm and term pregnancy.

PROBLEM: This study was aimed to isolate cDNAs for genes whose expression levels are dynamically regulated at the feto-maternal interface around parturition. METHOD: The suppression subtractive hybridization (SSH) method was used to compare the gene expression patterns of human choriodecidual membranes from term elective Caesarian delivery before labor (BL) and term vaginal delivery (VD). Northern blotting, quantitative real-time RT-PCR and in situ hybridization were performed to determine temporal and spatial expression of candidate clones. RESULT: After SSH procedure, we selected decorin from the cDNA library of BL for further investigation. The mean level of decorin transcription tended to be higher in BL samples than in VD or preterm samples. Decorin mRNA was mainly expressed in the decidual cells. Decorin gene expression was also upregulated in the term myometrium. CONCLUSION: These results suggest that dynamically increased expression of decorin in the choriodecidual membrane during parturition may be a part of the uterine preparation for labor.

Cloning, Molecular↗
PubMed2004

Effect of proteasome pathway on initiation of mouse labor induced by antiprogesterone.

PROBLEM: Various kinds of contraction-associated molecules are up-regulated at the initiation of labor. However, expression profiling has revealed that many molecules are also down-regulated. The effect of down-regulation of molecules by protein degradation on parturition is not known. METHODS OF STUDY: We administered lactacystin, a specific proteasome inhibitor, to mouse preterm birth model induced by antiprogesterone RU486 on day 16.0 post-coitus. NF-kappaB activity, and the levels of transcripts for oxytocin receptor, prostaglandin F(2alpha) receptor (FP), cyclooxygenase-1, -2, and interleukin-1beta in the uterus were examined by electrophoretic mobility shift assay and semi-quantitative reverse transcriptase-polymerase chain reaction, respectively. RESULTS: Administration of lactacystin significantly prolonged the time until the delivery of the first pup. FP mRNA level was solely elevated by RU486 treatment, and lactacystin significantly suppressed this up-regulation. CONCLUSIONS: Proteolysis by proteasomes in the uterus regulates the initiation of labor, at least in part, via control of contraction-associated molecules such as FP.

Abortifacient Agents, Steroidal↗
PubMed2004

[Effects of nutrient solution concentration on inorganic and glycyrrhizin contents of Glycyrrhiza glabra Linn].

Licorice, Glycyrrhiza glabra Linn., is one of herbal medicines widely used for various purposes, including as a sweetener and for gastric ulcer treatment. However, environmental destruction due to the harvesting of wild licorice is becoming a serious problem. We cultured licorice in a hydroponic system to examine the relation between the concentration of nutritional solution applied and glycyrrhizin content to determine the optimal nutrient solution concentration for commercial licorice production. Licorice growth and glycyrrhizin content in the root reached the highest values when the plants received nutrient solution approximately equivalent to a quarter unit of Hoagland solution. The results also indicated that the glycyrrhizin content does not correlate with the concentration of nutrient solution applied and/or inorganic contents absorbed, i.e., licorice may absorb large amounts of nutrient solution but the glycyrrhizin content may not increase.

Culture Media↗
PubMed2004

Analysis of clonality and HPV infection in benign, hyperplastic, premalignant, and malignant lesions of the vulvar mucosa.

To elucidate the pathogenesis of vulvar carcinomas, we studied clonality and human papillomavirus (HPV) infection in vulvar epithelial diseases. Monoclonal composition was demonstrated in all 9 invasive tumors (squamous cell carcinoma [SCC], 6; basal cell carcinoma, 1; malignant melanoma, 2), 15 of 20 cases of vulvar intraepithelial neoplasia (VIN), 7 of 9 cases of Paget disease, 2 of 6 cases of lichen sclerosus (LS), and 2 of 3 cases of squamous cell hyperplasia (SCH); high-risk type HPV was revealed in 5 of 6 SCCs and 17 of 20 VINs. These observations might imply that a subset of cases of LS and SCH result from a neoplastic proliferation, similar to VINs but not related to infection with high-risk type HPV. In 1 case of SCC with concurrent VIN 3 in an adjacent lesion, both lesions showed the same pattern of X chromosome inactivation and the presence of HPV-16 in episomal and integrated forms, suggesting that monoclonal expansion triggered by high-risk type HPV integration is an early event for carcinogenesis of HPV-associated SCC.

Carcinoma in Situ↗
PubMed2004

Human milk induces fetal small intestinal cell proliferation - involvement of a different tyrosine kinase signaling pathway from epidermal growth factor receptor.

Breast milk has non-nutritional protective effects on recipient infants. It has been speculated that bioactive substances present in human milk have important roles in protecting infants. However, the mechanisms by which such substances protect newborns are unclear. Therefore, we analyzed the growth-promoting activity of human milk and the intracellular signaling mechanism thereof using human fetal small intestinal (FHS 74 Int) cells. Epidermal growth factor (EGF) stimulated the proliferation of these cells. However, this stimulation was less effective than that of aqueous milk (5% vol/vol). The bioactivity of human milk was heat stable but protease sensitive. EGF receptor tyrosine kinase inhibitor did not repress the milk-induced growth-promoting effect on fetal small intestinal cells. Regarding the intracellular signaling pathway, the milk-induced cell proliferation pathway was tyrosine kinase dependent but was neither mitogen-activated protein (MAP) kinase nor phosphatidylinositol-3 (PI-3) kinase dependent. On the other hand, EGF-induced cell proliferation was tyrosine kinase, MAP kinase, and PI-3 kinase dependent. Rapid tyrosine phosphorylation of several intracellular proteins was detected after milk stimulation. Furthermore, the time course of phosphorylation induced by milk was different from that induced by EGF. The sizes of the proteins phosphorylated in response to milk were different from those of the Shc proteins phosphorylated in response to EGF. These results suggest that human milk induces fetal intestinal cell proliferation through a unique tyrosine kinase pathway different from the EGF receptor signaling pathway.

Cell Division↗
PubMed2004

Induction of glucose transporter 1 expression through hypoxia-inducible factor 1alpha under hypoxic conditions in trophoblast-derived cells.

Glucose transporter 1 (GLUT1) plays an important role in the transport of glucose in the placenta. During early pregnancy, placentation occurs in a relatively hypoxic environment that is essential for appropriate embryonic development, and GLUT1 expression is enhanced in response to oxygen deficiency in the placenta. Hypoxia-inducible factor-1 (HIF-1)alpha is involved in the induction of GLUT1 expression in other cells. The present study was designed to test whether HIF-1alpha is involved in hypoxia-induced activation of GLUT1 expression using trophoblast-derived human BeWo and rat Rcho-1 cells as models. GLUT1 mRNA and protein expression were elevated under 5% O2 or in the presence of cobalt chloride, which has been shown to mimic hypoxia. Using rat GLUT1 (rGLUT1) promoter-luciferase constructs, we showed that this up-regulation was mediated at the transcriptional level. Deletion mutant analysis of the rGLUT1 promoter indicated that a 184 bp hypoxia-responsive element (HRE) of the promoter was essential to increase GLUT1 reporter gene expression in response to low-oxygen conditions. BeWo and Rcho-1 cells cultured under 5% O2 or with CoCl2 showed increased expression of HIF-1alpha protein compared with those cultured under 20% O2. To test whether this factor is directly involved in hypoxia-induced GLUT1 promoter activation, BeWo and Rcho-1 cells were transiently transfected with an HIF-1alpha expression vector. Exogeneous HIF-1alpha markedly increased the GLUT1 promoter activity from constructs containing the HRE site, while the GLUT1 promoter constructs lacking the HRE site were not activated by exogenous HIF-1alpha These data demonstrate that GLUT1 is up-regulated under 5% O2 or in the presence of CoCl2 in the placental cell lines through HIF-1alpha interaction with a consensus HRE site of the GLUT1 promoter.

Blotting, Northern↗
PubMed2004

Cisplatin enhances the p53-independent apoptosis induced by a topoisomerase I inhibitor (CPT-11) in the lens epithelial tumors in transgenic mice.

We reported that CPT-11 could induce apoptosis in mouse lens epithelial tumors when it was administered to pregnant alphaT3 mice which developed epithelial cell carcinoma in situ in the lens in the perinatal period. p53-deficient alphaT3 mice were generated to analyze the influence of p53 status on tumor cells under combined chemotherapy. On the 16-18th gestational day, alphaT3 received a single i.p. administration of both CPT-11 and Cisplatin, and fetal lens epithelial tumors were examined two days later. Apoptosis in the p53-wild-type alphaT3 tumors was observed in a Cisplatin dose-dependent manner. In addition, it was found that Cisplatin augmented CPT-11-induced p53-independent apoptosis in p53-deficient alphaT3 mice.

Animals↗
PubMed2003

Inhibition of phosphorylation of a forkhead transcription factor sensitizes human ovarian cancer cells to cisplatin.

The Forkhead family transcription factor FKHRL1 is an inducer of apoptosis in its unphosphorylated form and was recently reported to be a substrate of Akt kinase. We studied the roles of FKHRL1 in both cisplatin-resistant Caov-3 (a papillary adenocarcinoma cell line) and cisplatin-sensitive A2780 human ovarian cancer cell lines. Treatment of Caov-3 cells but not A2780 cells with cisplatin transiently stimulated the phosphorylation of FKHRL1. Transfection experiments revealed that a kinase inactive-mutant of Akt or a triple mutant (TM) of FKHRL1, in which all three of the putative Akt phosphorylation sites were converted to alanine, was unable to phosphorylate the FKHRL1 protein in cells treated with cisplatin. Because the phosphorylated form of FKHRL1 is known to be localized in the cytoplasm, we examined whether cisplatin-induced phosphorylation of FKHRL1 might have an effect on the subcellular distribution of FKHRL1. Cisplatin induced the localization of FKHRL1 in the cytoplasm in Caov-3 cells but not in A2790 cells. Moreover, cisplatin induced the association of 14-3-3 protein with phosphorylated-FKHRL1 in Caov-3 cells but not in A2790 cells. Because the unphosphorylated form of FKHRL1 binds the Fas ligand promoter, thereby inducing apoptosis, we further examined the effect of the phosphorylation status of FKHRL1 on the activity of the Fas ligand promoter in the presence of cisplatin. Transfection with the kinase-inactive mutant of Akt or TM of FKHRL1 induced the activity of the Fas ligand promoter in Caov-3 cells. Moreover, exogenous expression of TM of FKHRL1 in Caov-3 cells decreased the cell viability after treatment with cisplatin. Our findings suggest that cisplatin causes the phosphorylation of FKHRL1 via a phosphatidylinositol 3-kinase/Akt cascade, and inhibition of this cascade sensitizes ovarian cancer cells to cisplatin.

14-3-3 Proteins↗