Biomedical subjects

Yuji Murata

Publications and source records attributed to Yuji Murata.

123 records · Page 7Linked to original sources

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

Decreased thyroid uptake of Tc-99m pertechnetate in patients with advanced-stage Sjögren syndrome: evaluation using salivary gland scintigraphy.

PURPOSE: The authors assessed the uptake of Tc-99m pertechnetate in the thyroid using salivary gland scintigraphy in patients with Sjögren syndrome and in healthy controls. MATERIALS AND METHODS: Salivary gland scintigraphy and a labial biopsy were performed in 73 patients with Sjögren syndrome. Based on the labial biopsy findings, 32 patients with a histopathologic grade of 1 or 2 were regarded as having early-stage Sjögren syndrome and 41 patients with a grade of 3 or 4 were regarded as having an advanced stage. After the administration of 370 MBq (10 mCi) Tc-99m pertechnetate, dynamic salivary gland scintigraphy was performed for 50 minutes. Lemon juice was used to stimulate the salivary glands, and the thyroid gland was included in the imaging area. Scintigraphy was also performed in an age- and sex-matched control group of 25 healthy persons. The thyroid uptake ratio was calculated for the scintigraphic images and compared among the three groups: healthy controls, patients with early-stage Sjögren syndrome, and those with advanced-stage Sjögren syndrome. RESULTS: When compared with the control group, the thyroid uptake ratio of the early-stage Sjögren syndrome group was not significantly different, whereas that of the advanced-stage group was significantly lower. CONCLUSIONS: Thyroid uptake of Tc-99m pertechnetate was less in patients with advanced-stage Sjögren syndrome than in patients with early-stage Sjögren syndrome or in healthy controls. Measuring the thyroid uptake of Tc-99m pertechnetate using salivary gland scintigraphy is an easy and useful method for assessing thyroid disorders in Sjögren syndrome and thus should be performed routinely.

Adolescent↗

PubMed2002

Clonal analysis and mutations in the PTEN and the K-ras genes in endometrial hyperplasia.

The patterns of X chromosome inactivation and mutations of PTEN and K-ras were evaluated in cases of endometrial hyperplasia to determine the presence of potentially premalignant neoplastic versus polyclonal benign cell populations. Endometrial glandular epithelial cells were collected by laser capture microdissection, and genomic DNAs were extracted. Following treatment with the methylation sensitive restriction endonuclease Hha I, polymerase chain reaction amplification was performed targeting a highly polymorphic short tandem repeat of the human androgen receptor gene (HUMARA). PTEN and K-ras gene mutations were evaluated by analysis of single-strand conformation polymorphism. Two pathologists performed histologic diagnosis of the lesions independently. Monoclonal composition was demonstrated in 13 of 15 (87%) endometrial hyperplasias with atypia and 17 of 31 (55%) complex hyperplasias without atypia. Cytological atypia is significantly associated with the clonal status of the endometrial hyperplasia (13/15 vs 17/31, P = 0.049). In contrast, all 14 normal endometrial tissue samples were polyclonal. PTEN gene mutations were detected in 4 of 13 (30%) monoclonal endometrial hyperplasias with atypia and 2 of 17 (12%) monoclonal endometrial hyperplasias without atypia but were not detected in polyclonal endometrial hyperplasias, with or without atypia. K-ras gene mutations were present in 3 of 13 (23%) monoclonal endometrial hyperplasias with atypia but not in 2 cases of polyclonal endometrial hyperplasia with atypia or in 26 cases of endometrial hyperplasia without atypia. K-ras mutation is thus significantly more frequently found in endometrial hyperplasias with atypia than those without atypia (3/15 vs 0/31, P = 0.030). This study indicates that most cases of endometrial hyperplasia with atypia and a high proportion of cases of endometrial hyperplasias without atypia originate from a single progenitor cell, possibly as a result of genetic alterations, rather than as a result of benign reactive processes.

Cell Transformation, Neoplastic↗

PubMed2002

Expression and regulation of 4F2hc and hLAT1 in human trophoblasts.

The neutral amino acid transport system L is a sodium-independent transport system in human placenta and choriocarcinoma cells. Recently, it was found that the heterodimer composed of hLAT1 (a light-chain protein) and 4F2 heavy chain (4F2hc), a type II transmembrane glycoprotein, is responsible for system L amino acid transport. We found that the mRNAs of 4F2hc and hLAT1 were expressed in the human placenta and a human choriocarcinoma cell line. The levels of the 4F2hc and hLAT1 proteins in the human placenta increased at full term compared with those at midtrimester. Immunohistochemical data showed that these proteins were localized mainly in the placental apical membrane. Data from leucine uptake experiments, Northern blot analysis, and immunoblot analysis showed that this transport system was partially regulated by protein kinase C and calcium ionophore in the human choriocarcinoma cell line. Our results suggest that the heterodimer of 4F2hc and hLAT1 may play an important role in placental amino acid transport system L.

Calcium↗

PubMed2002

Hyperreactio luteinalis associated with severe twin-to-twin transfusion syndrome.

Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies, with high perinatal loss and significant morbidity. The etiology of this syndrome remains unclear. Hyperreactio luteinalis is a rare benign condition characterized by maternal ovarian enlargement due to theca lutein cysts. We present 4 cases of hyperreactio luteinalis associated with severe TTTS. We detected maternal ovarian enlargement by prenatal ultrasonography in 2 cases, at the cesarean section in 1 case, and postpartum in 1 case. Three cases showed hydrops fetalis and all cases showed congestive cardiac failure. Serial amnioreduction was performed in all cases, and regression of hydrops fetalis and maternal ovarian enlargement occurred in 1 case. These cases suggest that the pathophysiology of TTTS is closely related to the etiology of hyperreactio luteinalis.

Adult↗

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↗

PubMed2002

Effectiveness of hormonal tourniquet by vasopressin during myomectomy through vasopressin V1a receptor ubiquitously expressed in myometrium.

To elucidate the mechanism by which myometrial vasopressin injection promotes hemostasis during myomectomy, we examined the expression of vasopressin V1a receptor transcripts in the myometrium. Vasopressin V1a receptor expression was ubiquitous, and the transcripts were detected in the myometrium not only of cycling and pregnant patients, but also of postmenopausal or GnRH agonist-treated patients. Based on these observations, we applied intraoperative myometrial vasopressin injection during myomectomy in a non-randomized study in a total of 84 patients. Vasopressin injection significantly reduced the intraoperative blood loss and postoperative hemoglobin fall in patients without and with GnRH agonist pretreatment. No serious complications occurred on account of the vasopressin injection. We conclude that intraoperative vasopressin injection is effective as a hormonal tourniquet even in GnRH agonist-pretreated myomectomy.

Adult↗

PubMed2002

Regulation of the PRL promoter by Akt through cAMP response element binding protein.

Regulation of the PI3K-protein kinase B/Akt (serine/threonine kinase) cascade by PRL-releasing peptide (PrRP) and insulin in GH3 rat pituitary tumor cells was investigated. PrRP and insulin rapidly and transiently stimulated the activation of Akt, and the PI3K inhibitor wortmannin blocked the PrRP- or insulin-induced activation of Akt. Both pertussis toxin (10 ng/ml), which inactivates Gi/Go proteins, and expression of a peptide derived from the carboxyl terminus of the beta-adrenergic receptor kinase I, which specifically blocks signaling mediated by the betagamma subunits of G proteins, completely blocked the PrRP-induced Akt activation, suggesting that Gi/Go proteins are involved in PrRP-induced Akt activation, as they are in the activation of ERK by PrRP. Moreover, to determine whether a PI3K-Akt cascade regulates rat PRL (rPRL) promoter activity, we transfected the intact rPRL promoter ligated to the firefly luciferase reporter gene into GH3 cells. PrRP and insulin activated the rPRL promoter activity. Pretreatment with wortmannin or cotransfection with a dominant-negative Akt partially but significantly inhibited the induction of the rPRL promoter by PrRP or insulin. Cotransfection with a constitutively active Akt induced the rPRL promoter activity and cotransfection with a dominant-negative cAMP response element-binding protein (CREB) completely abolished the response of the rPRL promoter to the constitutively active Akt. Furthermore, either treatment with PrRP and insulin or transfection with the constitutively active Akt induced the phosphorylation of CREB. These results suggest that PrRP and insulin activate a PI3K-Akt cascade that is necessary to elicit rPRL promoter activity via a CREB-dependent mechanism.

Animals↗

PubMed2002

RhoA/Rho-kinase cascade is involved in oxytocin-induced rat uterine contraction.

The RhoA/Rho-kinase cascade is involved in various cellular functions, including migration, proliferation, and smooth muscle contraction. We examined the potential role of this pathway in oxytocin-induced uterine contraction. The specific Rho-kinase inhibitor Y-27632 inhibited oxytocin-induced rat uterine contraction on d 21 of pregnancy in a concentration-dependent manner, whereas the extent of this inhibition was reduced in the nonpregnant uterus. Y-27632 had no effect on oxytocin-induced intracellular Ca(2+) mobilization in myometrial cells. Immunoblot analysis showed that oxytocin increased the level of myosin light chain phosphorylation, and this increase was attenuated by Y-27632. Oxytocin increased the phosphorylation of myosin-binding subunit of myosin phosphatase, one of the major substrates of Rho-kinase, and this increase was reduced by Y-27632. The expression of Rho-kinase protein was shown to increase in the uterus during pregnancy compared with the nonpregnant uterus, whereas the expression of RhoA protein remained at the same level during pregnancy. RT-PCR and Northern blot analysis showed that the expression of Rho-kinase was up-regulated at the transcriptional level during pregnancy. These results suggest that the RhoA/Rho-kinase pathway may have an important role in oxytocin-induced uterine contraction, and that up-regulation of Rho-kinase is involved in the mechanism underlying the increased contractility of the pregnant myometrium.

Amides↗

PubMed2002

Sweet elements of Siraitia grosvenori inhibit oxidative modification of low-density lipoprotein.

This study examined the ability of sweet elements extracted from Siraitia grosvenori (SG) to inhibit the oxidation of LDL. We monitored the formation of conjugated diene during copper-mediated LDL oxidation in the presence or absence of sweet elements of whole extract of SG (SG extract) or cucurbitane glycosides (CGs) purified from SG extract as sweet elements. CGs consist of Mogroside IV (Mog.IV), Mogroside V (Mog.V), 11-Oxo-mogroside V (11-Oxo-mog.V), and Siamenoside I (Sia.I). In addition, the effect of these elements on human umbilical vein endothelial cell (HUVEC)- mediated LDL oxidation was tested by measuring production of lipid peroxides. SG extract inhibited copper-mediated LDL oxidation in a dose-dependent fashion, but neither glucose nor erythritol suppressed the oxidation. Among CGs, 11-Oxo-mog.V significantly inhibited LDL oxidation, and prolongation of the lag time during LDL oxidation by 11-Oxo-mog.V was dose-dependent. The lag time (119.7 +/- 8.9 min) in the presence of 200 microM 11-Oxo-mog.V was significantly longer than that (76.8 +/- 5.5 min) of control (p < 0.01). In addition, SG extract and 11-Oxo-mog.V inhibited HUVEC-mediated LDL oxidation in a dose-dependent manner. These results demonstrate that SG extract can inhibit LDL oxidation and that 11-Oxo-mog.V, a sweet element of SG extract, provides the anti-oxidative property of SG which might reduce the atherogenic potential of LDL.

Cells, Cultured↗

PubMed2002

Expression of platelet-derived endothelial cell growth factor/thymidine phosphorylase in cervical intraepithelial neoplasia.

Angiogenesis contributes to the growth and secondary spreading of solid tumors. Platelet-derived endothelial cell growth factor (PD-ECGF)/thymidine phosphorylase (TP) has been identified as such an angiogenic factor. In this study, the expression of PD-ECGF/TP and VEGF was evaluated by immunohistochemical staining of tumor specimens from 40 patients with cervical intraepithelial neoplasia (10 with moderate dysplasia; 10 with severe dysplasia; 10 with carcinoma in situ; 10 with invasive carcinoma). The microvessel density was assessed by immunostaining for factor VIII-related antigen in the most highly neovascularized area. In both the nucleus and cytoplasm, the intensity of PD-ECGF/TP expression in carcinoma in situ and invasive carcinoma was significantly stronger than that in moderate dysplasia. However, the intensity of VEGF expression was not significantly different in the various specimens. The microvessel density in mild dysplasia was significantly different from that in carcinoma in situ (p<0.05), and that in invasive carcinoma (p<0.05). There was no significant relationship between the microvessel density and the expression of PD-ECGF/TP or that of VEGF. These results show that the expression of PD-ECGF/TP appears to be involved in the promotion of angiogenesis in cervical intraepithelial neoplasia.

Carcinoma in Situ↗

PubMed2002

Cervical fluid oncofetal fibronectin as a predictor of early ectopic pregnancy. Is it affected by blood contamination?

OBJECTIVE: To evaluate (1) the diagnostic usefulness of oncofetal fibronectin (fFN) in the cervical fluid in unruptured ectopic pregnancy, and (2) the contribution of maternal blood contamination of the specimen to the test results. STUDY DESIGN: A total of 111 cases in the first trimester of pregnancy, including 12 cases of ectopic pregnancy, 26 of spontaneous abortion and 73 of viable intrauterine pregnancy, were studied. fFN was determined with a commercial enzyme-linked immunosorbent assay kit with a threshold of 50 ng/mL in cervical fluid. To determine the effect of blood contamination on the fFN assay, the positive rate of the fFN test was examined when maternal blood in the first trimester was mixed with the dilution buffer. RESULTS: Eighty-three percent (10/12), 38% (10/26) and 12% (9/73) of cases with ectopic pregnancy, miscarriage and normal pregnancy, respectively, were positive for fFN. The positive rate in ectopic pregnancy was significantly higher than in normal pregnancy and spontaneous abortion. The test was positive for fFN in 8% with 0.5% of blood contamination, 67% with 1% contamination and 100% with 10% contamination.

Adult↗

PubMed2002

Maintained salivary function after brachytherapy in patients with head and neck carcinomas--evaluation using quantitative salivary gland scintigraphy.

The purpose of this study was to determine whether or not salivary gland dysfunction occurs within the first three months after brachytherapy in patients with head and neck carcinoma. Of the 20 patients with head and neck squamous cell carcinoma included in this study, 11 were treated with brachytherapy and the remaining 9 patients received external irradiation. All the patients underwent a salivary gland scintigraphy before and after radiotherapy. The scintigraphic parameters of each major salivary gland were then compared before and after the radiotherapy. In the brachytherapy group, none of the scintigraphic functional parameters showed a significant change before and after the radiotherapy. In contrast, all of the parameters with the exception of the uptake ratio (UR) of the submandibular glands significantly decreased after external irradiation. This observation was to be expected owing to the different irradiation doses administered by the two techniques. The scintigraphic technique used to evaluate salivary gland function should be used in future intensity-modulated radiation therapy salivary-gland-sparing studies in order to evaluate both the acute and chronic effects of irradiation in head and neck cancer patients.

Adult↗

PubMedDate not supplied

Estrogen and raloxifene inhibit the monocytic chemoattractant protein-1-induced migration of human monocytic cells via nongenomic estrogen receptor alpha.

OBJECTIVE: To investigate the effects of estradiol (E2) and raloxifene on the migration of human monocytic THP-1 cells to endothelium. DESIGN: A prospective comparative study. THP-1 cells, a human acute monocytic leukemia cell line, were used for the study. Migration assays were performed using transwell inserts. THP-1 cells were exposed to E2 or raloxifene in the presence of monocytic chemoattractant protein-1 (MCP-1), a major chemoattractant for monocytes. The cells were transfected with small interfering RNA (siRNA) against estrogen receptor (ER) alpha and ERbeta for gene silencing. ER expression was evaluated by Western blot analysis. RESULTS: MCP-1 induced the migration of the cells for 90 minutes. The addition of E2 or raloxifene significantly inhibited the MCP-1-induced migration for 90 minutes. Preincubation of THP-1 cells with an ER antagonist, ICI 182780, significantly attenuated the inhibitory effects of E2 and raloxifene. Whereas transfection with siRNA of ERalpha significantly attenuated the inhibition by E2 of MCP-1-induced monocyte migration, transfection with control siRNA or siRNA of ERbeta had no effect on the rapid inhibitory action of E2. Moreover, preincubation of THP-1 cells with a transcriptional inhibitor, actinomycin D, had no effect on the rapid inhibitory action of E2. CONCLUSIONS: Our findings suggest that both E2 and raloxifene inhibited the MCP-1-induced monocyte migration through nongenomic ERalpha. This result may explain one of the antiatherosclerotic effects of E2 and raloxifene on vasculature.

Atherosclerosis↗