Biomedical subjects

Yuji Murata

Publications and source records attributed to Yuji Murata.

At least 109 records · Page 6Linked to original sources

PubMed2003

Monoclonal expansion with integration of high-risk type human papillomaviruses is an initial step for cervical carcinogenesis: association of clonal status and human papillomavirus infection with clinical outcome in cervical intraepithelial neoplasia.

To define the natural history of cervical intraepithelial neoplasia (CIN) as related to clonal status, we evaluated 20 cases of CIN1 and 18 cases of CIN2 that had been clinically followed for 7 to 48 months at Osaka University Hospital. These included 10 cases that progressed, 15 cases that persisted, and 13 cases that regressed. We analyzed the clonal status of each case by analysis of the pattern of X-chromosomal inactivation. Human papillomavirus (HPV) infection was detected by PCR-RFLP analysis. CINs that are monoclonal or infected by high-risk HPVs are more likely to progress or persist than cases that are polyclonal or negative for high-risk HPVs (p = 0.009 for monoclonal vs polyclonal, p = 0.024 for high-risk HPV positive vs negative p = 0.024). Eighteen (90%) of 20 monoclonal, high-risk HPV-associated CINs progressed or persisted, whereas 9 (60%) of 15 polyclonal or high-risk HPV-negative CINs regressed. Therefore, the combination of clonality status and high-risk type HPV infection was significantly correlated with clinical outcome (p = 0.003). The physical status of the HPV genome was evaluated in 17 cases of HPV-16 positive CINs by real-time PCR. Of those, the HPV viral genome was present in both episomal and integrated forms in 14 CINs (84%), and 12 of these cases (86%) were monoclonal in composition. By contrast, all three CINs in which the HPV genome was present in episomal form were polyclonal. In one CIN1 that was polyclonal, HPV-16 was originally present in episomal form but after 24 months, the patient developed a monoclonal CIN3 in which the HPV-16 genome was present in mixed form. These results may imply that HPV viral integration into the host genomic DNA is associated with progression from polyclonal to monoclonal status in CIN. These events may play a fundamental role in the progression from low-grade to higher grade dysplasia of the cervical mucosa.

Clone Cells↗

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

Long-term neuroprotective effects of hypothermia on neonatal hypoxic-ischemic brain injury in rats, assessed by auditory brainstem response.

A method to assess long-term neurofunctional outcome of hypothermia on immature brains has not yet been clearly established. To investigate the effects of hypothermia on long-term neurofunctional outcome, we studied brainstem function using auditory brainstem response in adult rats after neonatal hypoxic-ischemic brain injury. Seven-day-old rats underwent a combination of left common carotid artery ligation and subsequent exposure to 8% O(2) for 1 h (n = 17). The rats were divided into three groups: hypothermia group (n = 6), normothermia group (n = 6), and sham control group (n = 5). During recovery from the hypoxic-ischemic insult, body temperature was reduced to 30 degrees C for 24 h in the hypothermia group, but was kept at 37 degrees C in the normothermia and sham control group. Three months later the rats were assessed by auditory brainstem response, then killed. The normothermia group showed increased III-V latencies and wave V abnormalities. Hypothermia significantly ameliorated wave V abnormalities. Injury to the ipsilateral inferior colliculus was also reduced in the hypothermia group compared with that in the normothermia group, and the degree of damage assessed histologically correlated well with auditory brainstem response findings. The current study demonstrates that postischemic hypothermia may provide effective and long-lasting neurofunctional as well as histopathologic protection to the immature brain.

Animals↗

PubMed2003

Epidermal growth factor enhances invasive activity of BeWo choriocarcinoma cells by inducing alpha2 integrin expression.

The trophoblast, an important component of the mammalian placenta, has several essential biological roles in the maintenance of pregnancy. First, trophoblast cells must attach to the uterine endometrium, and then they must invade to a depth at which the vascular network exists. Here, we investigated the effects of epidermal growth factor (EGF) on alpha2 integrin expression, adhesiveness to collagen, and invasive activity using human BeWo choriocarcinoma cells. EGF induced the expression of alpha2 integrin mRNA and protein, as shown by Northern blotting, Western blotting, and flow cytometry. Human chorionic gonadotropin (hCG) secretion was enhanced by the addition of EGF, which suggests that the BeWo cells functionally differentiated similarly to normal trophoblasts. EGF also dose-dependently stimulated the invasiveness of BeWo cells. Antibody against alpha2 integrin inhibited this effect, suggesting that it may be mediated by an increase of cell surface integrin. EGF had no effect on the adhesiveness of BeWo cells to collagen, whereas it stimulated the chemokinetic activity in a dose-dependent manner. The increase of chemokinetic activity was suppressed by antibody against alpha2 integrin. These results suggest that EGF may induce alpha2 integrin expression in trophoblast cells, thereby enhancing their invasiveness into the endometrium via an increase of their chemokinetic activity.

Cell Adhesion↗

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↗

PubMed2003

[Phase III additional clinical study of 111In-pentetreotide (MP-1727): diagnosis of gastrointestinal hormone producing tumors based on the presence of somatostatin receptors].

Additional phase III multicenter clinical study was performed to investigate the efficacy, safety, and usefulness of somatostatin receptor scintigraphy using 111In-pentetreotide (MP-1727), which binds to somatostatin receptors. Forty patients were included in the study; Group A: 18 patients, gastrointestinal hormone producing tumors had been detected with conventional imaging modalities, Group B: 22 patients, no tumors had been detected with conventional imaging modalities in spite of high serum hormone levels. By comparing the results of the octreotide suppression test, 12/16 cases (75.0%) of Group A and 11/19 cases (57.9%) of Group B were assessed as "effective." By comparing the results of immunohistological examination, 5/9 cases (55.6%) of Group A and 2/4 cases (50.0%) of Group B were assessed as "effective." Severe adverse events were not observed in any of the evaluable 35 cases. MP-1727 was judged as clinically useful in 11/16 cases (68.8%) of Group A and 5/19 cases (26.3%) of group B. These results suggest that MP-1727 scintigraphy is very useful for the diagnosis and decision of the therapeutic strategy of gastrointestinal hormone producing tumors.

Aged↗

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

Alendronate inhibits lysophosphatidic acid-induced migration of human ovarian cancer cells by attenuating the activation of rho.

Alendronate, a nitrogen-containing bisphosphonate, is a potent inhibitor of bone resorption used for the treatment and prevention of osteoporosis. Recent findings suggest that alendronate and other nitrogen-containing bisphosphonates inhibit the mevalonate pathway and thereby inhibit the synthesis of products derived from this metabolite. This, in turn, prevents the prenylation of a number of small GTPases, which regulate cell growth, motility, and invasion. We studied the effect of alendronate on in vitro migration of human ovarian cancer cells. Lysophosphatidic acid (LPA) induced a dose-dependent increase of migration of cancer cells by promoting Rho/Rho-associated kinase signaling. The induction of cancer cell migration by LPA was inhibited by the addition of alendronate in a dose-dependent manner. Treatment of ovarian cancer cells with alendronate resulted in inactivation of Rho, changes of cell morphology, loss of stress fiber formation, and focal adhesion assembly, and the suppression of phosphorylation of myosin light chain and tyrosine phosphorylation of focal adhesion proteins, which are essential processes for cell migration. The effects of alendronate on cancer cells were prevented by the addition of geranylgeranyol, which is the metabolic intermediate of the mevalonate pathway. These results suggest that alendronate inhibits Rho activation by preventing geranylgeranylation, which results in inhibition of LPA-induced migration of human ovarian cancer cells.

Alendronate↗

PubMed2002

Etidronate and hormone replacement therapy (HRT) for postmenopausal women with osteoporosis despite HRT.

Hormone replacement therapy (HRT) is effective treatment for postmenopausal bone loss and osteoporosis. However, postmenopausal women with low bone mass fail to respond after a few years of HRT and some postmenopausal women show no bone response to HRT. In these cases, additive therapy is necessary. Bisphosphonates are highly effective in postmenopausal osteoporosis. We investigated the effects of adding etidronate, a bisphosphonate, to HRT. The addition of etidronate to HRT improved bone density (4.40+/-1.12% increase per year) in patients showing no increase or even a decrease after at least 1 year of HRT (5.39+/-2.40% decrease per year).

Absorptiometry, Photon↗

PubMed2002

Inhibition of phosphorylation of BAD and Raf-1 by Akt sensitizes human ovarian cancer cells to paclitaxel.

We studied the roles of the phosphatidylinositol 3-kinase (PI-3K)-Akt-BAD cascade, ERK-BAD cascade, and Akt-Raf-1 cascade in the paclitaxel-resistant SW626 human ovarian cancer cell line, which lacks functional p53. Treatment of SW626 cells with paclitaxel activates Akt and ERK with different time frames. Interference with the Akt cascade either by treatment with PI-3K inhibitor (wortmannin or LY294002) or by exogenous expression of a dominant negative Akt in SW626 cells caused decreased cell viability following treatment with paclitaxel. Interference with the ERK cascade by treatment with an MEK inhibitor, PD98059, in SW626 cells also caused decreased cell viability following treatment with paclitaxel. Treatment of cells with paclitaxel also stimulated the phosphorylation of BAD at both the Ser-112 and Ser-136 sites. The phosphorylation of BAD at Ser-136 was blocked by treatment with wortmannin or cotransfection with the dominant negative Akt. On the other hand, the phosphorylation of BAD at Ser-112 was blocked by PD98059. We further examined the role of BAD in the viability following paclitaxel treatment using BAD mutants. Exogenous expression of doubly substituted BAD2SA in SW626 cells caused decreased viability following treatment with paclitaxel. Moreover, because paclitaxel-induced apoptosis is mediated by activated Raf-1 and the region surrounding Ser-259 in Raf-1 conforms to a consensus sequence for phosphorylation by Akt, the regulation of Raf-1 by Akt was examined. We demonstrated an association between Akt and Raf-1 and showed that the phosphorylation of Raf-1 on Ser-259 induced by paclitaxel was blocked by treatment with wortmannin or LY294002. Furthermore, interference with the Akt cascade induced by paclitaxel up-regulated Raf-1 activity, and expression of constitutively active Akt inhibited Raf-1 activity, suggesting that Akt negatively regulates Raf-1. Our findings suggest that paclitaxel induces the phosphorylation of BAD Ser-112 via the ERK cascade, and the phosphorylation of both BAD Ser-136 and Raf-1 Ser-259 via the PI-3K-Akt cascade, and that inhibition of either of these cascades sensitizes ovarian cancer cells to paclitaxel.

Antineoplastic Agents, Phytogenic↗

PubMed2002

Loss of one allele of the p53 gene in the lens epithelial tumor in transgenic mice suppresses apoptosis induced by a topoisomerase I inhibitor (CPT-11).

To examine whether CPT-11 can induce apoptosis in the mouse lens tumor, it was administered to pregnant alphaT3 mice, which developed epithelial tumors in the lens during the perinatal stage. Three different p53 genotypes were generated to analyze the influence of p53 status on tumor cells under chemotherapy. On day 16--17 of gestation, alphaT3 mice received an i.p. injection of CPT-11, and fetal lens tumors were examined 2 days later. Apoptosis in the tumors was observed in both a CPT-11 dose- and p53 gene copy-dependent manner. In addition, it was found that CPT-11 could also induce apoptosis via a p53-independent pathway.

Animals↗

PubMed2002

Apoptosis and related proteins during parturition in prostaglandin F receptor-deficient mice.

This study investigated whether apoptosis and related proteins are involved in parturition by comparative observation of FP-deficient mice without labor and wild type mice with vaginal delivery. We examined the expression of apoptosis, Fas, FasL, active caspase-3 and bcl-2 proteins in the amnion, placenta and decidua. DNA laddering in the amnion, placenta and decidua tissue did not significantly differ between FP-deficient and wild type mice on day 18 of pregnancy. Similar TUNEL staining results were found in all tissues of FP-deficient mice compared with those of wild type mice. A higher intensity of apoptotic cells was found in the decidua basalis. The index of TUNEL-positive cells were not significantly different in the amnion, placenta and decidua of FP-deficient mice compared with that of wild type mice on day 18 of pregnancy. Specific bands for Fas were clearly observed in the amnion, placenta and decidua tissue. FasL specific bands were observed in the placenta and decidua, but a few in amnion tissue. A great number of active caspase-3 specific bands were detected in decidua, while a few such bands were detected in the placenta and few bands in the amniotic tissue. Bands for bcl-2 were detected in the amnion, placenta and decidua tissue. The weakest band was in decidual tissue. Fas, FasL, active caspase-3, and bcl-2 specific bands did not show any significant differences between the two groups. These findings demonstrate that apoptosis, Fas, FasL, caspase-3, and Bcl-2 occur in mouse term placenta that is not involved in parturition.

Amnion↗

PubMed2002

Effects of neonatal hypoxic-ischemic brain injury on skilled motor tasks and brainstem function in adult rats.

In an attempt to establish more sensitive long-term neurofunctional measurements for neonatal hypoxic-ischemic brain injury, we examined skilled motor task and brainstem functions in adult rats after neonatal cerebral hypoxia-ischemia (H-I), using a staircase test and auditory brainstem response (ABR), respectively. Seven-day-old rats underwent a combination of left common carotid artery ligation and exposure to 8% O(2) for 1 h (n=16). The control animals only received sham operation (n=16). At 3 months of age, the staircase test and ABR were performed. In the staircase test, H-I animals showed marked impairment of skilled forelimb use in the side contralateral to the occluded artery, and the degree of brain damage correlated significantly to skilled forelimb use. In the ABR, H-I animals showed brainstem dysfunction assessed by measuring interpeak latencies for waves III-V and I-V. We also examined the brainstem with antibodies specific for activated caspase-3, a protein involved in initiation of apoptosis, and observed that caspase-3 was activated in the ipsilateral inferior colliculus at 24 h after H-I. The present study shows that both the staircase test and ABR are sensitive and objective long-term neurofunctional measurements that can be used in future studies to assess therapeutic intervention in this neonatal cerebral H-I model.

Age Factors↗

PubMed2002

Lysophosphatidic acid induces focal adhesion assembly through Rho/Rho-associated kinase pathway in human ovarian cancer cells.

OBJECTIVE: The level of lysophosphatidic acid (LPA) is elevated in patients with ovarian cancer, and LPA has been reported to have a pivotal role in cancer dissemination. In the current study, the effect of LPA on the motility of ovarian cancer cells was investigated. METHODS: We analyzed the effects of LPA on the migration activity, the focal adhesion formation, and the tyrosine phosphorylation of focal adhesion proteins in human ovarian cancer cell lines Caov-3 and OVCAR-3. Inhibitors of the small GTPase Rho, one of its downstream effectors (Rho-associated kinase (ROCK)), myosin light chain kinase (MLCK), and myosin light chain (MLC) phosphatase were used to examine the mechanism of LPA-induced cellular effects. RESULTS: LPA enhanced the migration of ovarian cancer cells and facilitated their invasion. Rho and ROCK played essential roles in the migratory process, as evidenced by the inhibition of migration and focal adhesion formation of cancer cells by Clostridium botulinum C3 exoenzyme (C3), an inhibitor of Rho, or Y-27632, an inhibitor of ROCK. LPA also evoked the formation of focal adhesions and tyrosine phosphorylation of focal adhesion kinase and paxillin, all of which were inhibited by C3 or Y-27632. CONCLUSION: These results suggest that LPA induced the migration of ovarian cancer cells, at least in part, through accelerated formation of focal adhesions mediated by Rho/ROCK-induced actomyosin contractility. This study may provide the basis for new therapies to control the metastasis of ovarian cancer.

Cell Movement↗

PubMed2002

Fetal gene transfer by intrauterine injection with microbubble-enhanced ultrasound.

Intrauterine injection of naked DNA expressing luciferase, green fluorescent protein (GFP), or beta-galactosidase (beta-gal) and fluorescein isothiocyanate-labeled oligodeoxynucleotide (FITC-ODN), in combination with microbubble-enhanced ultrasound (US), referred to as the "shotgun method" (SGM), produced high-level protein expression in fetal mice. With the SGM, luciferase expression increased approximately 10(3)-fold in comparison with expression after injection of naked DNA alone. Electron microscopic analysis demonstrated transient formation of pores on the skin surface after intraamniotic (i.a.) injection with the SGM. Widespread expression of GFP and beta-gal and delivery of FITC-ODN were observed in multiple fetal tissues adjacent to the injection points. PCR analysis indicated that germline transfection was only transient following intraperitoneal (i.p) injection, and there was no evidence of transfer of the reporter gene to the offspring. Thus, SGM might provide a useful means to clarify the molecular mechanisms of genetic diseases in utero, as well as a tool to develop gene therapies in utero.

Amnion↗

PubMed2002

Mass treatment with nevirapine to prevent mother-to-child transmission of HIV/AIDS in sub-Saharan African countries.

OBJECTIVE: In 2001, an estimated 800000 children were newly infected with HIV, almost all through mother-to-child transmission (MCTC), and 90% of these children were born in Africa. In such resource-poor settings, cheaper and more easily administered antiretroviral drugs should be available for use. Mass treatment of an intrapartum and neonatal single dose of nevirapine regimen has been suggested as an effective strategy to prevent MCTC, yet this strategy has never been conducted in clinical trials. By discussing the advantages and disadvantages of it, we analyze the possibility of implementing this regimen. METHODS: We reviewed public health strategies to prevent MCTC in resource-poor settings, and discuss whether or not mass treatment of an intrapartum and neonatal single dose of nevirapine regimen can be recommended as one therapy in sub-Saharan Africa due to its simplicity of distribution and use, long-term efficacy, and cost-effectiveness. RESULT: Recent studies in Uganda showed the high efficacy and cost-effectiveness of a single dose of nevirapine only to HIV/AIDS-positive pregnant women. The characteristics of nevirapine also meet the requirements of mass treatment. Mass treatment of nevirapine would increase access to antiretroviral drugs among pregnant women because they can access nevirapine without volunteer counseling and testing, which 31% of pregnant women in developing countries refused to accept due to the fear of stigmatization. No serious adverse effects or drug resistance to this regimen were reported through the studies in Uganda. CONCLUSION: Mass treatment of a single-dose nevirapine can be recommended as one alternative therapy, and further research is recommended to obtain more information about the efficacy, side-effects, drug resistance, and compliance of this strategy.

Adult↗

PubMed2002

Investigation of intraplacental villous arteries by Doppler flow imaging in growth-restricted fetuses.

OBJECTIVE: The purposes of our study were to assess the ability of color and power Doppler sonography to depict the blood flow in the intraplacental villous arteries and to evaluate whether the blood flow of intraplacental villous arteries in a normal pregnancy is different from that in a pregnancy that is associated with intrauterine growth restriction. STUDY DESIGN: Eighty-five women with uncomplicated pregnancy and 16 women with intrauterine growth-restricted fetuses between 27 and 38 weeks of gestation were examined by color and power Doppler imaging. The blood flow of intraplacental villous arteries was analyzed comparatively. The pulsatility index and peak systolic velocity were measured. RESULTS: A unit of 1 intraplacental villous artery-1 and its branches were seen as 1 cotyledon by color and power Doppler imaging. The cotyledon was easily identified and counted. Each cotyledon contained only 1 intraplacental villous artery-1. This method can visualize the intraplacental villous artery-1 to intraplacental villous artery-4 in normal pregnancies. The terminal villous arteries beyond intraplacental villous artery-4 were not imaged. The number of detectable intraplacental villous artery-1 in 1 placenta in intrauterine growth restriction was significantly lower than that in normal pregnancy. The number of detectable branches in intrauterine growth restriction was also significantly lower than in normal pregnancy. No intraplacental villous artery-4 blood flow was found in women with intrauterine growth restriction. In examined arteries, pulsatility index decreased and peak systolic velocity increased significantly with advancing gestational age (P <.02). At any given gestational age, pulsatility index and peak systolic velocity in the peripheral arteries were significantly lower than those in the upstream arteries in normal pregnancy (P <.001). The pulsatility index value of each intraplacental villous artery was also lower than that of the umbilical artery in the women with intrauterine growth restriction (P <.05). There were no differences in pulsatility index in each artery between the groups, although there were a few high pulsatility index values in intrauterine growth restriction. CONCLUSION: Color Doppler and power flow sonography are valuable tools for the detection of the blood flow of intraplacental villous arteries. The decrease in the number of detectable intraplacental villous artery-1 and branches was associated with intrauterine growth retardation.

Adult↗