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Biomedical subjects

Yuji Murata

Publications and source records attributed to Yuji Murata.

At least 19 recordsLinked to original sources
PubMed2007

Involvement of nuclear factor-kB activation through RhoA/Rho-kinase pathway in LPS-induced IL-8 production in human cervical stromal cells.

Interleukin-8 (IL-8) is a chemokine that recruits and activates neutrophils in stromal tissue and plays an essential role in cervical ripening. Nuclear factor-kB (NF-kB) is known to be important for the up-regulation of IL-8 gene expression. We examined the molecular mechanisms responsible for NF-kB activation in IL-8 production in cervical stromal cells. Lipopolysaccharide (LPS) and IL-1beta stimulated IL-8 production by cervical stromal cells in a dose-dependent manner. Pretreatment of cervical stromal cells with inhibitors of RhoA (C3 transferase exoenzyme), Rho-kinase (Y-27632) or NF-kB (BAY11-7082) effectively blocked LPS-induced IL-8 release. In contrast, IL-1beta-induced IL-8 production was significantly blocked by BAY11-7082, but not by C3 transferase exoenzyme or Y-27632. Pull-down assays showed that LPS activated RhoA, but IL-1beta caused only a lower level of activation. Transfection of the cervical stromal cells with RhoA small interfering RNA (siRNA) inhibited LPS-stimulated IL-8 production, whereas IL-1beta-induced IL-8 production was not significantly inhibited by knockdown of RhoA with siRNA. Using an NF-kB transcription reporter vector, luciferase assays demonstrated that incubation with LPS or IL-1beta induced the activation of NF-kB in cervical stromal cells. Activation of NF-kB by LPS was inhibited by treatment with C3 exoenzyme, Y-27632 or RhoA siRNA. However, inhibition of the RhoA/Rho-kinase pathway did not attenuate the activation of NF-kB by IL-1beta. These results suggest that LPS-induced IL-8 production is accompanied by enhanced NF-kB activation through the RhoA/Rho-kinase pathway in human cervical cells.

ADP Ribose Transferases↗
PubMed2007

A clinicoanatomical study of the novel nerve fibers linked to stress urinary incontinence: the first morphological description of a nerve descending properly along the anterior vaginal wall.

When performing anterior colporrhaphy for cystocele, most pelvic surgeons have not considered the neuroanatomy that contributes to urethral function. The aim of the study was to anatomically identify nerve fibers located in the anterior vagina associated with the pathogenesis of incontinence and pelvic organ prolapse. Anterior vaginal specimens were obtained from 17 female cadavers and 33 cases of clinical cystocele by anterior vaginal resection. The specimens were step-sectioned and stained with hematoxylin-eosin, S100 antibody, and tyrosine hydroxylase antibody. As a result, descending nerves 50-200 microm in thickness were identified between the urethra and vagina. They were located more than 10 mm medially from a cluster of nerves found almost along the lateral edge of the vagina and stained with S100 and tyrosine hydroxylase antibody, originated from the cranial part of the pelvic plexus, and appeared to terminate at the urethral smooth muscles. The authors classified the density of S100 positive nerve fibers in the anterior vaginal wall obtained from clinically operated cases of cystocele into three grades (Grade 1, nothing or a few thin nerves less than 20 microm in diameter; Grade 2, thick nerves more than 50 microm in diameter and thin nerves; Grade 3, more than 3 thick nerves in one field at an objective magnification of 40x). Mean urethral mobility (Q-tip) values (28.1 degrees +/-+/- 19.6 degrees ) observed in the Grade 3 cases was significantly lower than those (50.0 degrees +/-+/- 27.4 degrees and 59.4 degrees +/-+/- 19.9 degrees ) in Grade 2 and Grade 1, respectively. In addition, the presence of preoperative or postoperative stress urinary incontinence in the cases of Grade 1 was significantly higher than those of the cases with S100 positive stained nerves. In conclusion, the novel nerve fibers immunohistochemically identified in the anterior vaginal wall are different from those of the common nervous system or the pelvic floor and are associated with the pathogenesis of urethral hypermobility.

Aged↗
PubMed2006

Hypoxia represses the differentiation of Rcho-1 rat trophoblast giant cells.

BACKGROUND: A hypoxic environment is known to be essential for early placentation. A low oxygen tension induces hypoxia-inducible factor-1 (HIF-1alpha) which may play an important role as a transcription factor in maintaining the proliferative and undifferentiated phenotype in human trophoblasts. METHODS: We analyzed the effect of a low oxygen tension on the rat trophoblast giant cell differentiation pathway using Rcho-1 cells which were derived from rat choriocarcinomas and consist of trophoblast stem cells. RESULTS: We found that a low oxygen tension suppressed the morphological changes and steroidogenesis during differentiation. The anticipated downregulation of the Id-1 transcription factor, a negative regulator of trophoblast giant cell differentiation, was not observed in the hypoxic environment. On the other hand, deferoxamine, which mimics hypoxia and induces HIF-1alpha, caused downregulation of Id-1 transcription factor and trophoblast giant cell differentiation. CONCLUSION: These results indicate that hypoxia represses rat trophoblast giant cell differentiation via an HIF-1alpha-independent pathway.

Animals↗
PubMed2006

Post-ischemic hypothermia reduced IL-18 expression and suppressed microglial activation in the immature brain.

Inflammation is an important factor for hypoxia-ischemia (HI) brain injury. Interleukin (IL)-18 is a proinflammatory cytokine which may be a contributor to injury in the immature brain after HI. To investigate the effects of post-HI hypothermia on IL-18 in the developing brain, 7-day-old rats were subjected to left carotid artery ligation followed by 8% oxygen for 60 min and divided into a hypothermia group (rectal temperature 32 degrees C for 24 h) and a normothermia group (36 degrees C for 24 h). The IL-18 mRNA was analyzed with real-time RT-PCR, and the protein level was analyzed by Western blot, and the location and source of IL-18 were assessed by immunohistochemistry. The significant increase of the IL-18 mRNA was observed in the ipsilateral hemispheres of the normothermia group at 24 h and 72 h after HI compared with controls, but the level in the ipsilateral hemispheres of the hypothermia group was significantly reduced at both time points, compared with the normothermia group, respectively. The IL-18 protein level in the ipsilateral hemispheres of the normothermia group significantly increased at 72 h after HI compared with controls, however, the protein level of the hypothermia group was significantly decreased, compared with the normothermia group. IL-18-positive cells were observed throughout the entire cortex, corpus callosum (CC) and striatum in the ipsilateral hemispheres of normothermia group at 72 h after HI, however, little positive cells were observed in the hypothermia group. Double labeling immunostaining found that most of the IL-18-positive cells were colocalized with lectin, which is a marker of microglia. The number of ameboid microglia (AM) in the normothermia group was significantly increased in cortex and CC, compared with the number in controls, but there were very few ramified microglia (RM) in these areas. In contrast, the number of AM in the hypothermia group was significantly decreased in cortex and CC, compared with the number in the normothermia group, and there were no significant differences in the number of AM and RM between the hypothermia group and controls. In conclusion, we found that IL-18 mRNA and the protein level were attenuated by post-HI hypothermia and that post-HI hypothermia may decrease microglia activation in the developing brain.

Animals↗
PubMed2006

Peripheral quantitative computed tomography (pQCT) is useful for monitoring bone mineral density of the patients who receive hormone replacement therapy.

OBJECTIVE: A forearm fracture (Colles' fracture) is often the first sign of osteoporosis and should alert the patient and physician to the possibility of underlying skeletal fragility. Therefore, the establishment of a more accurate and reliable method for the measurement of bone mineral density (BMD) at the distal radius would be beneficial for the patients who suffer from osteoporosis. The objective of the present study was to evaluate the usefulness of peripheral quantitative computed tomography (pQCT) to assess the change of BMD at the distal radius in early postmenopausal women who receive hormone replacement therapy (HRT). METHODS: Twenty healthy early postmenopausal women who were diagnosed as osteoporosis or osteopenia were randomized to either HRT or placebo treatment. We analyzed BMD of the distal radius by pQCT, lumbar spine by dual-energy X-ray absorptiometry (DXA) and the biochemical markers of bone turn over (osteocalcin, deoxypyridinoline) every 6 months. RESULTS: The placebo group showed a significant decrease from the baseline in the trabecular BMD of the radius at 12 months (7.4+/-2.5%) (p<0.05), whereas the HRT group showed a slight increase (0.7+/-2.2%). The changes in the trabecular BMD of the radius between the HRT and placebo groups were statistically different at 12 months (p<0.05). On the other hand, in the cortical BMD of the radius, no significant differences were seen between the changes of bone densities in the HRT and control groups after 1 year of treatment. pQCT could detect a significant loss of BMD of the radius in early postmenopausal women after 1 year and HRT prevented its loss. CONCLUSION: Our preliminary clinical trial showed that pQCT might be useful for the early detection of bone loss in early postmenopausal women and for the monitoring BMD of the patients who receive HRT.

Absorptiometry, Photon↗
PubMed2006

A decrease of cell proliferation by hypothermia in the hippocampus of the neonatal rat.

Hypothermia is a potential therapy for cerebral hypoxic ischemic injury of not only adults but also neonates. However, the side effects of hypothermia in the developing brain, where a massive amount of neurogenesis occurs, remain unclear. We investigated the proliferation of neural progenitor cells by systemic application of the thymidine analog 5-bromodeoxyuridine (BrdU) in neonatal rats in a severe hypothermic environment. The rat pups were divided into two groups, a hypothermia group (30 degrees C: n=10) and a normothermia group (37 degrees C: n=10). After the pups were placed for 21 h in each environment, 100 mg/kg/day of BrdU was injected intraperitoneally to label dividing cells, and then the pups were sacrificed at 24 h. We examined the number of BrdU-labeled cells in the subventricular zone of the periventricle and the subgranular zone of the dentate gyrus. In the hypothermic environment, BrdU-labeled cells significantly decreased in number in the dentate gyrus, but not in the periventricular region. Thus, the severe hypothermic environment induced a decrease of neurogenesis in the neonatal rat. These observations are noteworthy regarding clinical hypothermia therapy following cerebral hypoxic ischemic injury during the perinatal period.

Aging↗
PubMed2006

Long-term neuroprotective effects of carbon dioxide on neonatal rat hypoxic-ischemic brain injury: an experimental study of skilled motor tasks.

OBJECTIVE: This study was undertaken to investigate the long-term effect of hypercapnia on neonatal hypoxic-ischemic brain injury, we tested its effect in a neonatal rat hypoxia-ischemia model. STUDY DESIGN: The rats were subjected to unilateral carotid artery ligation and exposure to 8% oxygen for 30 minutes. Six percent carbon dioxide was administered to the neonatal rats during unilateral hypoxia-ischemia, and the motor function and neurologic outcomes were determined 3 months later. RESULTS: Significant motor functional improvement was observed in the hypercapnic animals, as judged by the Montoya staircase test. The unilateral brain injury was significantly ameliorated in the hypercapnic animals, and this amelioration was well correlated with the motor functional performance. Cerebral blood flow during hypoxia-ischemia, monitored by laser Doppler flowmetry, was better preserved in the hypercapnic animals. CONCLUSION: Our results suggest that mild hypercapnia during hypoxia-ischemia may provide long-lasting motor functional as well as neurologic protection for immature brains, possibly by increasing cerebral blood flow during hypoxia.

Animals↗
PubMed2006

Mouse model of human infertility: transient and local inhibition of endometrial STAT-3 activation results in implantation failure.

Embryo implantation involves a series of biochemical reactions and its failure is an important therapeutic target of infertility treatment. We established an infertile mouse model using transient and local suppression of signal transducer and activator of transcription-3 (STAT-3) activity by STAT-3 decoy transfer into the uterine cavity during implantation, resulting in <30% implantation. This infertility is caused by suppression of decidualization, which is indispensable for implantation, and independent of progesterone. These conditions may mimic clinically unexplained infertility. Our results suggest that STAT-3 could be a useful target for diagnosis and therapy of human implantation failure.

Animals↗
PubMed2006

Simple and highly efficient method for transient in vivo gene transfer to mid-late pregnant mouse uterus.

Up- and down-regulation of various genes in the placenta, decidua and amnion has been reported during the mid-late period of pregnancy and in pregnancy-related complications, such as preeclampsia and preterm labor. However, whether this gene regulation at the feto-maternal interface directly influences the physiology/pathophysiology of disease remains unknown. In order to study this problem, transient gene transfer into the pregnant uterus at mid-late term would be a useful tool. We injected exogenous plasmid entrapped using a commercially available Hemagglutinating Virus of Japan Envelope (HVJ-E) vector system (GenomONE Neo, Ishihara Sangyo) into the extra-amniotic space of the upper part of the pregnant mouse uterus on day 14.5 post-coitus (p.c.). Luciferase activity driven by the cytomegalovirus promoter was detectable for 3 days after transfection in the upper, middle and lower part of the uterus. beta-Galactsidase activity was localized in the basal lamina of the placenta, the decidual membrane and the fetal membrane. Exogenous plasmid was not transmitted to the fetus. The course of pregnancy was not disturbed by this procedure; rupture of membranes, intrauterine fetal growth restriction and preterm birth were not observed. Thus, we demonstrated that this transient gene transfer method is highly efficient and minimally invasive, and expect that this procedure will be a useful tool to analyze the pathophysiology of pregnancy-related disorders.

Animals↗
PubMed2006

Prognostic significance of p53 mutation in suboptimally resected advanced ovarian carcinoma treated with the combination chemotherapy of paclitaxel and carboplatin.

The prognostic significance of p53 mutation, microsattelite instability and DNA mismatch protein hMLH1 expression in suboptimally resected advanced ovarian carcinoma treated with the combination chemotherapy of paclitaxel and carboplatin was evaluated. The overall combination chemotherapy response rate and the complete remission rate were significantly higher among patients with mutant p53 tumors than those with wild-type p53 tumors (35/42 (83%) vs. 32/58 (55%); P=0.003 and 18/42 (43%) vs. 16/58 (28%); P=0.03, respectively). This tendency apparently existed in non-serous carcinoma, but not in serous carcinoma. Univariate analysis showed that the risk of death due to disease and risk of progression was significantly lower among patients with p53 mutation (P=0.0357 and 0.0281, respectively). However, the presence of microsattelite instability or loss of hMLH1 expression was not associated with either the clinical response or prognosis. Determining p53 mutational status can be useful in predicting therapeutic response to drugs in ovarian carcinoma, especially in non-serous tumors.

Adenocarcinoma, Clear Cell↗
PubMed2006

The effects of repeated corticosteroid administration on the neurogenesis in the neonatal rat.

OBJECTIVE: The purpose of this study is to clarify the effects on the brain including neurogenesis pretreated with repeated doses of dexamethasone in the neonatal rat. STUDY DESIGN: The 4-day-old Sprague Dawley rats were pretreated with 4 different regimens, namely, single administration of dexamethasone, 2-dose administration, 3-dose administration, and saline administration as a control. Concurrently, bromodeoxyuridine (BrdU), which was incorporated into the dividing cells, was administered. We examined body weight, brain weight, and the number of BrdU-labeled cells in the subventricular zone (SVZ), the subgranular zone (SGZ), and the cortex. RESULTS: Both the body and brain weight of the rats pretreated with dexamethasone were significantly decreased compared with those given saline. Quantitative analysis of BrdU-labeled cells revealed the significant dose-dependent decreases in the SVZ, the SGZ, and the cortex with the dexamethasone treatment. CONCLUSION: We concluded that the decreases in neurogenesis caused by repeated antenatal corticosteroid therapy might result in the adverse effects on the size of the head at birth.

Aging↗
PubMed2006

Correlations between 18F-FDG uptake by bone marrow and hematological parameters: measurements by PET/CT.

The aim of this study was to investigate the correlations between (18)F-FDG uptake by bone marrow and various hematological parameters. Forty-eight patients who underwent FDG-PET/CT studies and also received hematological examinations within 5 days before or after the PET study were included in this study. All patients had not received chemotherapy. FDG uptake by bone marrow was measured as a standardized uptake value (SUV) on three-dimensional PET/CT fusion images, and the uptake ratio (UR) of the SUV of bone marrow to the SUV of longitudinal dorsal muscle was calculated. The correlations between the SUV and the UR of bone marrow and various hematological parameters were evaluated. Bone marrow FDG uptake was strongly correlated with the white blood cell counts but was not significantly correlated with the red blood cell and platelet counts. The neutrophil count was significantly correlated with bone marrow FDG uptake but the lymphocyte count was not. FDG uptake by bone marrow was specifically correlated with the neutrophil count, suggesting that the FDG uptake by bone marrow reflects marrow metabolism that is mainly regulated by granulocyte progenitors and stimulated by endogenous hematopoietic growth factors. They may also be helpful in interpreting PET images, especially for diagnosing bone marrow involvement by malignancy.

Adult↗
PubMed2006

In-vivo visualization of radiation-induced apoptosis using (125)I-annexin V.

BACKGROUND: As apoptosis occurs in tumors within a short time after irradiation, the detection of the frequency of apoptosis may be useful as an indicator of the effect of treatment. For the evaluation of apoptosis under these conditions, tissue extraction from patients is indispensable. AIM: To develop a noninvasive imaging technique to measure and monitor apoptosis in tumor cells caused by X-irradiation using (125)I-radiolabeled annexin V. METHODS: The tumors used were human ependymoblastomas, which were transplanted into nude mice. The tumors were irradiated at 2, 5 or 10 Gy. (125)I-annexin V was administered intravenously 6 h after irradiation. In the 5 Gy irradiation group, the isotope was injected at various time intervals (3, 6 and 12 h) after irradiation. Three hours after the injection, the mice were sacrificed, the tumors were quickly removed and frozen sections were prepared at 6 and 40 microm thickness using a cryomicrotome. In autoradiographic imaging, the tumor-to-muscle ratios were compared in the respective irradiated groups. In addition, apoptosis detection by the in-situ end-labeling (Klenow) assay was conducted on the same sections. The number of Klenow-positive cells was counted in 100 x fields for each section. RESULTS: Both autoradiography and immunohistochemical staining showed a significantly higher frequency of apoptosis in the neoplasms in all irradiated groups than in the control group (P<0.05). Although immunohistochemical staining revealed a peak apoptosis frequency in the 5 Gy irradiated group, autoradiography revealed a peak in the group receiving a lower dose than 5 Gy. When the time from irradiation to annexin injection was varied, both imaging methods showed a peak apoptosis frequency in the group receiving the injection 6 h after irradiation. CONCLUSION: It is possible to predict the effect of treatment in cancer in a noninvasive manner by apoptosis imaging in vivo after radiotherapy.

Animals↗
PubMed2006

Sporadic fetal heart rate decelerations associated with electrocortical changes in fetal lambs.

AIM: The purpose of this study was to determine a relationship between sporadic fetal heart rate (FHR) decelerations and fetal electrocortical changes in physiologically normal sheep fetuses. MATERIALS AND METHODS: A total of 20 experimental observations were conducted on eight chronically instrumented fetal lambs. For electrocorticogram (ECoG) recording, two stainless steel electrodes were implanted bilaterally on the fetal parietal skull. Classifications of ECoG tracings were visually divided into periods of low, high, intermediate and transitional voltage. During day and night observations, sporadic FHR decelerations related to fetal ECoG changes were counted. RESULTS: We found that 65% of the total sporadic FHR decelerations occurred in relation to fetal ECoG changes. The largest number of sporadic FHR decelerations was associated with a switch from low voltage to high voltage ECoG (37%). However, the greatest frequency of sporadic FHR decelerations occurred during intermediate ECoG periods (34%). CONCLUSION: The majority of sporadic FHR decelerations observed in physiologically normal sheep fetuses were associated with fetal ECoG changes.

Animals↗
PubMed2006

Prospective study of non-closure or closure of the peritoneum at cesarean delivery in 124 women: Impact of prior peritoneal closure at primary cesarean on the interval time between first cesarean section and the next pregnancy and significant adhesion at second cesarean.

AIM: The aim of this study was to evaluate the effect of non-closure of the peritoneum at cesarean delivery on postoperative complications and the interval time to the next pregnancy, and to investigate the incidence of adhesion following cesarean and the association between adhesion formation and peritoneal closure. METHODS: One hundred and twenty four women scheduled for cesarean section were randomized to either closure of both the visceral and parietal peritoneum (C-group, n = 70) or non-closure (NC-group, n = 54). At repeated cesarean, the levels and extent of adhesion, operating time, and any complications were examined. RESULTS: There was no difference in the incidence of postoperative complications at the first cesarean section. The operating time of the C-group was significantly longer than that of the NC-group. The frequency of analgesic use was significantly higher in the C-group. The time interval from cesarean section to the next pregnancy in the NC-group was significantly shorter than that in the C-group. There are no significant differences between the rates of complications in the C-group and the NC-group at repeated cesarean. The incidence of adhesion in the C-group was significantly higher than that in the NC-group (P < 0.05). The mean total operating time and the mean interval time for skin incision to delivery in the C-group were significantly longer than those in the NC-group (P < 0.05 and P < 0.001, respectively) at repeated cesarean section. CONCLUSIONS: Non-closure of the peritoneum at cesarean delivery appears to have no adverse effect on postoperative recovery, it also decreases the number of analgesic doses and shortens the operating time and may be more desirable in achieving a next pregnancy. The present study demonstrated that surgical peritoneal closure resulted in more advanced adhesion formation. The practice of non-closure of the peritoneum should be performed at cesarean.

Adult↗
PubMed2006

Reduction of aquaporin-8 on fetal membranes under oligohydramnios in mice lacking prostaglandin F2 alpha receptor.

AIM: To investigate the association between aquaporin-8 (AQP-8: a water channel protein) expression in fetal membranes and oligohydramnios during near-term and postdate pregnancy, we set up an oligohydramnios model using prostaglandin F2 alpha receptor (FP)-deficient mice. METHODS: Pregnant FP-deficient mice from 14 to 21 gestational days (GD) were killed to measure the amniotic fluid volume (AFV), and fetal membranes were collected for the analysis of aquaporin-8 expression. RESULTS: The AFV was highest at 14 GD, and was significantly decreased to 28% and 0% at 20 GD and 21 GD, respectively, compared with the volume at 14 GD. Immunohistochemistry and immunoblot analysis showed that aquaporin-8 was expressed in the basal component of fetal membranes, and that the protein level was significantly decreased to 60% at 20 GD compared with that at 14 GD. CONCLUSIONS: We demonstrated that AQP-8 expression in the fetal membrane was decreased at post term in FP-deficient mice. Our findings suggest that aquaporin-8 in fetal membranes may be involved in the regulation of AFV, especially when oligohydramnios occurs.

Amniotic Fluid↗
PubMed2006

Rapid detection of trisomy 21 by gene dosage analysis using quantitative real-time polymerase chain reaction.

AIM: Rapid detection of fetal aneuploidy helps inform a mother's choice about the course of her pregnancy. Obtaining results by fluorescent in situ hybridization (FISH) requires more than 24 h, and thus a more rapid method is needed. METHODS: Conventional G-banding and FISH for chromosome 21 were performed for cultured amniocytes. Genomic DNA was extracted from uncultured amniocytes obtained from 23 patients. TaqMan polymerase chain reaction (PCR) primers were designed to amplify the potassium voltage gated channel gene on chromosome 21q22.12 and the ribosomal phosphoprotein gene on 18q21.1. Quantitative real-time PCR was performed for these two gene fragments and the differences of the threshold cycle (Ct) of the two genes (Ct 18-Ct 21) were calculated for each sample. RESULTS: G-banding revealed that 19 patients had a normal karyotype and four had trisomy 21. FISH resulted in one case of a false positive. The Delta Ct values (Ct 18-Ct 21) of trisomy 21 patients were significantly higher than the values of individuals with normal karyotypes (P < 0.001) and there was no overlapping. CONCLUSIONS: Fetal trisomy 21 is rapidly detectable by gene dosage analysis from amniocytes using quantitative real-time PCR.

Amniotic Fluid↗