Biomedical subjects

Koichiro Shimoya

Publications and source records attributed to Koichiro Shimoya.

At least 37 records · Page 2Linked 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

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↗

PubMed2003

Fetal hemorrhage associated with congenital intestinal atresia.

We encountered two cases of severe intrauterine hemorrhage associated with congenital intestinal atresia. In both cases, the first sign that necessitated immediate clinical management was the abnormal fetal heart rate patterns, represented by prolonged bradycardias and late decelerations. This occurred immediately after the onset of labor. An emergency cesarean section was performed on both patients and, despite being born with severe anemia, the condition of the infants was excellent. We found that continuous fetal heart rate monitoring should be performed if polyhydramniosis suspected, when the fetus is diagnosed with congenital intestinal atresia and when changes in intrauterine pressure are clinically expected, such as at the onset of labor or after amniocentesis.

Adult↗

PubMed2003

Fractalkine (FRK) levels in amniotic fluid and its production during pregnancy.

Fractalkine is a new CX(3)C chemokine that has chemoattractant activity for T cells, monocytes and natural killer (NK) cells. Western blot analysis revealed that fractalkine protein was detected as a 95 kDa band in both the amniotic fluid and the amnion during the second and third trimesters. Immunohistochemistry using an anti-fractalkine polyclonal antibody revealed positive staining of epithelial cells in amnion and trophoblasts in both the second and third trimesters. Neonatal urine also contained detectable amounts of fractalkine. RT-PCR detected fractalkine mRNA transcripts in the amnion. To determine whether fractalkine receptor (CX(3)CR1)-positive cells were present in amniotic fluid and amnion, we performed RT-PCR using specific primers for CX(3)CR1. CX(3)CR1-positive cells had migrated into the amniotic fluid and the amnion. The present findings suggest that fractalkine found in amniotic fluid may contribute to the immunodefence mechanism during pregnancy.

Amnion↗

PubMed2003

Highly efficient and minimally invasive in-vivo gene transfer to the mouse uterus using haemagglutinating virus of Japan (HVJ) envelope vector.

The uterus is obviously critical in implantation, development of the fetus and parturition. Endometrial cancer derived from endometrial epithelium is one of the common malignancies in the female reproductive tract. In order to clarify the local mechanisms of reproductive physiology and establish a non-systemic therapeutic strategy for reproductive failure as well as for endometrial cancer, we applied haemagglutinating virus of Japan envelope (HVJ-E) vector to in-vivo gene transfer into the uterine cavity of IVCS mice. Injection of HVJ-E vector into mouse uterine cavity on day 1.5 post coitum (p.c.) introduced a reporter gene approximately 120-fold more efficiently than introduction using the cationic liposome method. The expression of the introduced gene continued for at least 3 days. The plasmid vector was localized in the endometrial epithelium, whereas oligo deoxynucleotides were distributed throughout the epithelium, stromal cells and myometrium. HVJ-E vector did not affect the pregnancy rate, course of pregnancy, litter size, fetal growth in utero or parturition, and did not transfect the exogenous gene to the fetus. These results indicate that gene transfer into the uterus using HVJ-E vector is highly efficient and safe during pregnancy, and results in a well controlled distribution of the exogenous DNA. We believe that this procedure should be widely applicable for investigations of reproductive physiology as well as for methods of local gene therapy in the uterus.

Animals↗

PubMed2003

Postischemic hyperthermia induced caspase-3 activation in the newborn rat brain after hypoxia-ischemia and exacerbated the brain damage.

The effects of postischemic hyperthermia were investigated in the newborn rat brain after hypoxia-ischemia (HI). Seven-day-old rats were subjected to left carotid artery ligation followed by 8% oxygen for 30 min, and divided into a hyperthermia group (rectal temperature at 39 degrees C for 6 h) and a normothermia group. Hyperthermia resulted in an approximately 5-fold increase in activated caspase-3 24 h after HI when compared with the normothermia group, and gross loss of brain tissue was observed only in the hyperthermia group at 7 and 30 days after HI. Our results show that postischemic hyperthermia exacerbates HI injury in immature brains, and that the mechanism is strongly associated with activation of an apoptotic pathway.

Animals↗

PubMed2003

Serial transvaginal sonography of a case of complete hydatidiform mole.

Sonography has achieved a position of preeminence in the diagnostic evaluation of molar gestation. However, little information is available about the serial change of the transvaginal sonographic features of molar pregnancy. We describe a case of complete hydatidiform mole, and present serial transvaginal views taken during the early gestational period.

Adult↗

PubMed2003

Pregnancy outcome of embryonic/fetal pleural effusion in the first trimester.

OBJECTIVE: To investigate the incidence of embryonic/fetal pleural effusion in the first trimester and its pregnancy outcome. METHODS: A total of 965 viable singleton pregnancies confirmed by sonography between 7 and 10 weeks were examined to estimate the incidence of embryonic/fetal pleural effusion. When initial transvaginal sonography showed pleural effusion, serial ultrasound examinations were performed. RESULTS: Pleural effusion was detected in 12 pregnancies (incidence, 1.2%; 95% confidence interval, 0.7-2.2), which involved bilateral thoracic cavities in all cases. The pregnancy outcome was assessed among 14 cases of pleural effusion, including 2 previously reported cases from the same institution. Among these, 12 pregnancies (86%) miscarried by 14 weeks' gestation. Karyotype was abnormal in 9 (82%) of 11 cases in which chromosomal analysis was successfully performed. Of these, 6 (67%) were 45,X. CONCLUSIONS: The results suggested that embryonic/fetal pleural effusion in early pregnancy was associated with poor pregnancy outcome such as spontaneous abortion and chromosomal abnormality.

Adult↗

PubMed2002

Detection of oxidative stress in seminal plasma and fractionated sperm from subfertile male patients.

OBJECTIVES: Oxidative stress in the reproductive system is thought to affect the fertilizing ability of sperm. Since 8-hydroxydeoxyguanosine (8-OHdG) and lipid peroxides are widely used as markers to quantify oxidative stress, we compared 8-OHdG and lipid peroxide concentrations in seminal plasma and spermatozoa from subfertile and fertile men. STUDY DESIGN: Semen obtained from 37 men of subfertile couples (21 men with normozoospermia and 16 with asthenozoospermia) and from eight fertile volunteers were examined. Seminal plasma and spermatozoa were fractionated by four-step discontinuous Percoll gradient centrifugation. 8-OHdG in seminal plasma was measured by ELISA, and lipid peroxides in seminal plasma and spermatozoa were determined using a thiobarbituric acid (TBA) assay. RESULTS: The concentrations of 8-OHdG and lipid peroxides in the seminal plasma of the subfertile group were significantly higher than those of the fertile group. There were no significant differences in these values between patients with normozoospermia and asthenozoospermia. In all four fractions obtained by Percoll gradient fractionation, the lipid peroxide levels in spermatozoa recovered from subfertile males were significantly higher than those of fertile controls. CONCLUSIONS: Seminal plasma and spermatozoa from subfertile males showed elevated levels of oxidative stress that were detectable in ejaculated semen specimens by ELISA or TBA assay. Even the spermatozoa fraction considered to be mature and normal showed elevated oxidative stress in the subfertile group. Our results confirm the importance of oxidative stress in male reproductive function, and could be applied for the selection of patients for antioxidant therapy.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2002

The expression of secretory leukocyte protease inhibitor (SLPI) in the fallopian tube: SLPI protects the acrosome reaction of sperm from inhibitory effects of elastase.

BACKGROUND: Secretory leukocyte protease inhibitor (SLPI) is a protein found in various fluids, including parotid secretions, cervical mucus, seminal plasma and ascites, and is a potent inhibitor of human leukocyte elastase activity. The objective of the study was 2-fold, to evaluate (i) the presence of SLPI in the Fallopian tube, and (ii) the effect of SLPI on the acrosome reaction of sperm. METHODS AND RESULTS: Western blot analysis revealed that SLPI protein was detected as a 12 kDa band in the isthmus, ampulla and infundibulum of the Fallopian tube. Immunohistochemistry using an anti-SLPI polyclonal antibody revealed positive staining of epithelial cells in the Fallopian tube. RT-PCR demonstrated that SLPI transcripts were expressed in the Fallopian tube. To determine the function of SLPI in the Fallopian tube, the effects of SLPI and elastase on the sperm acrosome reaction were examined. SLPI prevented the reduction of the acrosome reaction by elastase in a dose-dependent manner. CONCLUSION: The present findings suggest that SLPI in the Fallopian tube contributes to sperm-oocyte interaction.

Acrosome Reaction↗

PubMed2002

Detection of fractalkine in human seminal plasma and its role in infertile patients.

BACKGROUND: Fractalkine is a relatively newly discovered CX(3)C chemokine, which is a chemoattractant for T cells, monocytes and natural killer cells. Several reports have demonstrated the association between chemokine levels in seminal plasma and semen quality. The fractalkine levels in ejaculates from normal donors and infertile male patients with or without asthenozoospermia, were examined and correlated with sperm motility and morphology. METHODS AND RESULTS: Western blot analysis showed fractalkine protein to be present in the seminal plasma. Fractalkine titres in the seminal plasma of infertile men with asthenozoospermia (0.64 +/- 0.04 microg/ml; n = 58) were lower than those in patients without asthenozoospermia (0.94 +/- 0.10 microg/ml; n = 22, P < 0.01) and fertile donors (1.04 +/- 0.07 microg/ml; n = 10, P < 0.001). There was no significant difference between fractalkine levels in patients with and without leukospermia. No significant correlation was found between fractalkine and interleukin-8 levels in seminal plasma. Sperm motility was positively correlated (R(2) = 0.14, P < 0.001) with fractalkine concentration. The existence of CX(3)CR-positive leukocytes in semen was confirmed using specific primers for CX(3)CR. CONCLUSIONS: These results suggest that fractalkine is a chemokine associated with sperm motility and the migration of CX(3)CR-positive leukocytes into semen.

Base Sequence↗

PubMed2002

Diagnosis of ureterocele with transvaginal sonography.

We report here the case of a 49-year-old Japanese woman who presented to the clinic for uterine cervical cancer screening and who had a history of repeated cystitis. Normal imaging demonstrated no abnormalities of the genital organs; however, transvaginal ultrasound revealed ureterocele. Given the lack of ureterocele-related symptoms and the absence of hydronephrosis, the patient was followed up using repeat sonographic studies and intravenous pyelography. In conclusion, transvaginal sonography is a useful tool in the diagnosis of urinary diseases. In patients with recurring urological symptoms, it is important to check for gynecological diseases as well as urologic diseases. This can be provided well with transvaginal sonography.

Female↗