Biomedical subjects

N Kanayama

Publications and source records attributed to N Kanayama.

At least 19 recordsLinked to original sources

PubMed2006

Expression of Golf in the rat placenta: Possible implication in olfactory receptor transduction.

Olfactory receptors are G-protein coupled receptors and are encoded by an extremely large and diverse family of genes in mammals. There is increasing evidence that olfactory receptors are widely distributed in many organs, suggesting that olfactory receptors do not only recognize airborne odorants but also play important roles in chemotaxis or organ construction in embryo. In this study, we investigated whether olfactory receptors and their transduction molecule, Golf are expressed in the rat placenta. By RT-PCR, we identified 11 different olfactory receptor genes, which are all members of class II, in the rat placenta cDNAs, and our results suggested that particular members of the olfactory receptor gene family might be preferentially expressed in the placenta. By western blot analysis, we demonstrated that Golf protein is expressed in the placenta and its expression levels are developmentally regulated. We found that Golf immunoreactivity is exclusively localized to giant cell trophoblasts and spongiotrophoblast cells. These findings raised a possibility that a particular subset of olfactory receptors might be coupled with Golf and function in giant cell trophoblasts and spongiotrophoblast cells.

Animals↗

PubMed2005

Dendritic cell differentiation and maturation in embryonic rat liver: immunohistochemistry and electron microscopy with reference to dendritic cell contacts.

This study investigated the dendritic cell (DC) differentiation in embryonic rat liver utilizing in situ ultrastructural characterization and immunohistochemistry. The study revealed the existence of DCs early in hepatic ontogeny with positive immune staining to the OX-62 monoclonal antibody. DCs existed in three differentiating stages: immature, mature and transitional forms in between. At 14 and 16 days of gestation, immature and transitional forms of DCs dominated. Mature cells increased significantly in number through late gestational days (18 days onwards). DCs (particularly mature and moderate mature forms) revealed signs of active phagocytosis manifested by the existence of cytoplasmic phagosomes and heterophagosomes. At 18 days of gestation as well as newborn liver mature DCs displayed two distinct morphological phenotypes according to the degree of development of either the smooth endoplasmic reticulum or the lysosomal compartment. Mature DCs delineated close appositions to other DCs, hepatocytes, and clustering with lymphocytes especially through their cellular processes. The features of phagocytosis and DC-T-cell contacts may signify a role of DCs in immune surveillance in the embryonic liver.

Animals↗

PubMed2005

Role of prostaglandin E2 receptor subtypes in ovarian follicle growth in the rat in vivo. Correlation with interleukin-8 and neutrophils.

UNLABELLED: This study was conducted to elucidate the role of three of prostaglandin E2 (PGE2) receptor subtype (EP2, EP3, and EP4) agonists in the process of follicular growth. The influence of these agonists on ovarian expression of intimately related factors to follicle development (neutrophils and interleukin-8 (IL-8)) was also investigated. Immature female Wistar rats were injected once with these agonists and killed 48 hours later. Another group of rats were injected pregnant mare serum gonadotrophin. For evaluation of follicle growth, morphometric assessment of antral and ovulatory follicles was performed in serial ovarian sections. The study demonstrated that, EP2 and EP4 agonists showed the maximum follicle counts and diameters versus the control. EP2 and EP4 agonists mimicked PMSG induced follicle growth. Injection of the three agonists induced neutrophil infiltration into theca layer. EP4 agonist showed the most intense ovarian neutrophil accumulation. In addition, dense ovarian IL-8 expression was observed only after EP4 agonist injection. CONCLUSIONS: Our data suggests that: 1) EP2 and EP4 receptors are the key PGE2 receptors engaged in follicle growth. 2) Ovarian IL-8 expression and neutrophil infiltration are chiefly mediated via the EP4 receptor. EP2 and EP4 receptor agonists may be candidates for promising reagents that induce follicle maturation in clinical or agricultural fields. This knowledge could provide numerous targets for manipulation of fertility.

Animals↗

PubMed2002

Production of cartilage link protein by human granulosa-lutein cells.

Link protein (LP), an extracellular matrix protein in cartilage, stabilizes aggregates of hyaluronic acid (HA) and proteoglycans, including aggrecan and inter-alpha-trypsin inhibitor (ITI). We have shown previously that cartilage LP is present in the maturing rat and mouse ovary. In the present study, we have employed immunohistochemistry to examine the anatomical distribution of cartilage LP in the human ovary. The expression of cartilage LP was selectively detected in the cells within the granulosa compartment of the preovulatory dominant follicle. The HA-positive granulosa-lutein cells were found to be a cartilage LP-positive subpopulation. We subsequently studied the in vitro expression of cartilage LP in cultured human granulosa-lutein cells obtained at oocyte retrieval for in vitro fertilization. Analysis of cultured cells by enzyme-linked immunoaffinity assay, Western blotting and immunofluorescence microscopy revealed that gonadotropin stimulates cartilage LP production. Time-course studies indicated that the cartilage LP production was induced as early as with gonadotropin stimulation for 2 h, and the effect was sustained up to 8 h. Western blot analysis further revealed the presence of the macroaggregates composed of HA, ITI and cartilage LP in the gonadotropin-stimulated granulosa-lutein cell extracts. Collectively, the present results raise the possibility that cartilage LP forms extracellular structures that may have a regulatory function in the developing follicle in the human ovary.

Adult↗

PubMed2001

Developmental changes in PSD-95 and Narp mRNAs in the rat olfactory bulb.

Glutamate is the main neurotransmitter in the olfactory bulb. Recently, postsynaptic-density 95 (PSD-95) and neuronal activity-regulated pentraxin (Narp) have been reported to be pivotal for targeting and clustering of NMDA receptors and AMPA receptors, respectively. We thus investigated the expressions of PSD-95 and Narp mRNAs in the rat developing olfactory bulb. PSD-95 mRNA was already expressed in most neurons on the first postnatal day (P1). On the other hand, Narp mRNA expression was weakly seen only in mitral cells on P1. Thereafter, we found initial expression of Narp mRNA on P7 in periglomerular cells, and on P14 in granular cells, indicating that in the developing olfactory bulb PSD-95 mRNA expression precedes Narp mRNA expression, and that the expression pattern of Narp mRNA seems to be well correlated with the maturation of the neurons. These results indicate that PSD-95 and Narp play important roles in making efficient excitatory synapses in the developing rat olfactory bulb, and suggest that olfactory neurons might first express PSD-95 for making efficient NMDA receptors and thereafter express Narp for efficient AMPA receptors.

Animals↗

PubMed2001

Use of secondarily revised VH genes in IgE antibodies produced in mice infected with the nematode Nippostrongylus brasiliensis.

Although a high level of IgE is produced after primary infection with Nippostrongylus brasiliensis (Nb), most of the IgE antibodies (Abs) are not specific to the worm. Analyses with Western blotting and enzyme-linked immunosorbent assay (ELISA) revealed that the IgE Abs from Nb-infected BALB/c mice did not show reactivity with Nb-derived excretory-secretory proteins (NES) and antigens present in the cell-free extracts of the worm. Monoclonal IgE Abs obtained from the Nb-infected mice were not reactive with these Nb antigen either. To characterize Nb-induced IgE response, we used (QM x C57BL/6)F1 (QBF1) mice that bear the knock-in 17.2.25 VHDJH segment (VHT) encoding a VH region specific to 4-hydroxy-3-nitrophenylacetyl hapten, and express VHT-encoded antigen receptors on 80-85% of their B cells. Consistent with the frequency of VHT-positive B cells, more than 80% of IgE Abs induced in QBF1 B cells that were cultured with LPS plus IL-4 were found to bear VHT-encoded H chains. In contrast, when QBF1 mice were infected with Nb, less than 10% of Nb-induced IgE Abs were found to use VHT. The QBF1-derived IgE did not react with Nb antigens either. Taken together, data suggest that Nb-induced IgE response in mice is not merely the result of polyclonal activation of B cells, but may involve a mechanism that revises Ig genes secondarily.

Animals↗

PubMed2001

Calcium-induced changes in chondroitin sulfate chains of urinary trypsin inhibitor.

Urinary trypsin inhibitor (UTI) has several roles other than protease inhibition. It is suggested that UTI inhibits calcium influx in cultured cells and that the chondroitin sulfate chain of UTI may play an important role. In order to clarify the mechanistic features of this phenomenon, the chondroitin sulfate chain of UTI was analyzed by (1)H-NMR. The samples were highly purified UTI dissolved in D(2)O in the presence or absence of Ca(2+), Mg(2+) and Na(+). 1D-spectra were obtained and T(1) values of detected signals were estimated from the inversion-recovery method. The addition of Ca(2+) to UTI caused a chemical shift to downfield, line broadening and a reduction of T(1) values at several signals from chondroitin sulfate moiety (especially at axial H-2 of GalNAc), whereas Mg(2+) and Na(+) had no significant effect. Some of the signals in the linkage region of chondroitin sulfate chain showed marked line broadening by Ca(2+). The reduction of T(1) values implies formation of a complex. It is suggested that Ca(2+) generates the sulfate salt and interacts with other polar groups in the chondroitin sulfate chain, thereby causing bridging between UTI molecules. Several properties of UTI may be related to this interaction of Ca(2+) with chondroitin sulfate chains.

Calcium↗

PubMed2001

Characterization of binding properties of urinary trypsin inhibitor to cell-associated binding sites on human chondrosarcoma cell line HCS-2/8.

Urinary trypsin inhibitor (UTI) forms membrane complexes with UTI-binding proteins (UTI-BPs) and initiates modulation of urokinase-type plasminogen activator (uPA) expression, which results in UTI-mediated suppression of cell invasiveness. It has been established that suppression of uPA expression and invasiveness by UTI is mediated through inhibition of protein kinase C-dependent signaling pathways and that human chondrosarcoma cell line HCS-2/8 expresses two types of UTI-BPs; a 40-kDa UTI-BP (UTI-BP(40)), which is identical to link protein (LP), and a 45-kDa UTI-BP (UTI-BP(45)). Here we characterize binding properties of UTI-BPs.UTI complexes in the cells. In vitro ligand blot, cell binding and competition assays, and Scatchard analyses demonstrate that both UTI-BP(40) and UTI-BP(45) bind (125)I-UTI. A deglycosylated form of UTI (NG-UTI), from which the chondroitin-sulfate side chain has been removed, binds only to UTI-BP(40). Additional experiments, using various reagents to block binding of (125)I-UTI and NG-UTI to the UTI-BP(40) and UTI-BP(45) confirm that the chondroitin sulfate side chain of UTI is required for its binding to UTI-BP(45). Analysis of binding of (125)I-UTI and NG-UTI to the cells suggests that low affinity binding sites are the UTI-BP(40) (which can bind NG-UTI), and the high affinity sites are the UTI-BP(45). In addition, UTI-induced suppression of phorbol ester stimulated up-regulation of uPA is inhibited by reagents that were shown to prevent binding of UTI to the 40- and 45-kDa proteins. We conclude that UTI must bind to both of the UTI-BPs to suppress uPA up-regulation.

Binding Sites↗

PubMed2001

Variation of des-gamma-carboxyprothrombin (PIVKA-II) levels in cord blood throughout gestation.

The variation of des-gamma-carboxyprothrombin (PIVKA-II, protein induced by vitamin K absence) levels in umbilical cord blood throughout gestation was examined using a highly sensitive method, electrochemiluminescence immunoassay (ECLIA). PIVKA-II levels in infants without any complications were low, but modestly high, exceeding the normal range of healthy adults during the preterm period, followed by a remarkable increase after the 37th week of gestation. Among infants complicated with severe preeclampsia a marked increase of PIVKA-II levels was observed in preterm infants, showing a good correlation with the existence ofinfarctions on the placenta. On the other hand, among infants complicated with preterm premature rupture of the membranes (PROM) in which antibiotics were administered during the prenatal period, a moderate elevation of PIVKA-II levels was observed. These data suggest that the normal range of PIVKA-II in fetuses is modestly high compared with adults and any deficient status of vitamin K would not exist throughout the preterm period. Nevertheless, the vitamin K status might readily fall into a deficient condition in term infants. Furthermore, it is notable that vitamin K deficiency would be induced in complicated gestation with severe preeclampsia and medication with antibiotics.

Biomarkers↗

PubMed2001

Activated protein C prevents development of phosphatidylserine-induced intrauterine growth restriction in mice.

We examined the effect of activated protein C (APC) on the development of intrauterine growth restriction (IUGR) in an experimental animal model we established. The IUGR in mice was induced by artificial phosphatidylserine (PS)/phosphatidylcholine (PC) microvesicles that represent procoagulant phospholipids derived from activated platelets. This model represents the placental insufficiency associated with the phospholipid-induced hypercoagulable state in placental circulation. APC prolonged the activated partial thromboplastin time (aPTT) using mouse plasma and dose dependently inhibited thrombin generation in a chromogenic assay in defibrinated plasma of mice. Administration of exogenous APC at concentrations that maximally inhibited thrombin generation in defibrinated plasma prevented a significant reduction in fetal body weight and induced marked histological changes including congestion and fibrin depositions in IUGR mouse placentas. These results suggest that the inhibition of thrombin generation in the placental circulation by APC prevents the development of IUGR that is dependent on coagulation associated with PS/PC from activated platelets.

Animals↗

PubMed2001

Intraplacental coagulation in intrauterine growth restriction: cause or result?

Growth-restricted fetuses with complications of pregnancy exhibit significantly increased perinatal morbidity and mortality compared with normal growth fetuses. Coagulation-related lesions such as uteroplacental vessel thrombosis and perivillous coagulation in the placentas with intrauterine growth restriction (IUGR) are reported in complicated pregnancy, while fibrin depositions and intervillous thrombi are observed in half of the placentas of full-term uncomplicated pregnancy. These observations raise the question whether coagulation in the placental circulation is a cause for the development of IUGR. Recently published IUGR models in animals demonstrate that antiphospholipid antibodies and procoagulant platelet-derived phospholipids induce IUGR with histopathological changes of coagulation-related lesions in the placenta. These experiments suggest that enhanced coagulation in the placental circulation can induce IUGR and that hypercoagulable states remain one of the important factors in the development of IUGR.

Animals↗

PubMed2001

Is factor XII deficiency related to recurrent miscarriage?

Factor XII (FXII) is an important protease that plays a major role in the initiation of the intrinsic pathway of blood coagulation. Although congenital FXII deficiency is not associated with a clinical bleeding tendency, it can be identified on a routine coagulation test, such as a prolonged activated partial thromboplastin time. This deficiency is a rare autosomal recessive disorder. It is still unclear whether FXII deficiency causes any disorders during pregnancy. Recurrent miscarriages and placental abruption were reported in cases with FXII deficiency. We successfully treated a woman whose pregnancy was complicated by congenital FXII deficiency. We report her clinical courses of gestation, delivery, and puerperium and discuss the role of maternal FXII associated with pregnancy. In our case, courses of gestation and delivery were normal. Postpartum uterine bleeding was, however, prolonged due to a subinvolution of the puerperal uterus. Our results indicate that, except for postpartum uterine contraction, FXII does not play a major role in gestation and delivery. We suggest that FXII deficiency is not associated with recurrent miscarriage and that normal gestation and vaginal delivery are possible even in cases with congenital FXII deficiency. We assert that the possible correlation of FXII deficiency with recurrent miscarriage merits reevaluation.

Abortion, Habitual↗

PubMed2001

Vasospasms are characteristic in cases with eclampsia/preeclampsia and HELLP syndrome: proposal of an angiospastic syndrome of pregnancy.

We attempted to prove the occurrence of generalized vasospasms in cases with eclampsia/preeclampsia and HELLP syndrome and to suggest the existence of an angiospastic syndrome of pregnancy. Sixteen cases with severe preeclampsia were evaluated. Among them, three cases were complicated by eclampsia and one case with HELLP syndrome. Cranial magnetic resonance angiography (MRA) was performed in 15 cases, and celiac angiography was performed in one case. Vasospasms were observed in 12 cases (75.0%), including all cases involving eclampsia and HELLP syndrome, and cerebral infarction was observed in one case. Typical vasospasms were found by MRA in the middle and posterior cerebral arteries with peripheral ischemic changes in cases with severe preeclampsia and eclampsia. Vasospasms of the hepatic arteries were observed by celiac angiography in a case with HELLP syndrome. Vasospasms are characteristic for patients with eclampsia/preeclampsia and HELLP syndrome, and the existence of an angiospastic syndrome of pregnancy is proposed.

Adult↗

PubMed2001

Predictive values of coagulation/fibrinolysis parameters for the termination of pregnancy complicated by severe preeclampsia.

We investigated coagulation/fibrinolysis parameters for significant differences between patients with early-onset severe preeclampsia (< 32 weeks gestation, wG) and those with late-onset severe preeclampsia (> or = 32 wG). A decrease in antithrombin (AT), protein C (PC), and free protein S (PS) activities and an increase in plasmin-alpha2-plasmin inhibitor complex (PIC), thrombin-antithrombin complex (TAT), and FDP D-dimer (D-dimer) were observed. However, there were no statistical differences between the two groups. Once preeclampsia occurred and it developed severe, the changes in coagulation/fibrinolysis parameters became more severe in spite of early-onset preeclampsia or late-onset preeclampsia. We also investigated coagulation/fibrinolysis abnormalities in 101 patients with severe preeclampsia. A significant increase in WBC, RBC, Hb, Ht, TAT, PIC, and D-dimer and a significant decrease in platelet (Plt) counts and AT activity were observed. deltaPlt (the difference between platelet counts in early gestation and before delivery) was -5.0 x 10(4)/microL in cases with severe preeclampsia. Among patients with severe preeclampsia, coagulation/fibrinolysis changes before delivery were typical for patients with cesarean section compared with those with successful vaginal delivery. These facts suggest that an excessive hypercoagulable state is associated with the termination of pregnancy resulting from the aggravation of preeclampsia. From the viewpoint of coagulation/fibrinolysis changes, the termination of pregnancy could be recommended when the levels of parameters exceed the following values; deltaPlt > -6.0 x 10(4) microL, D-dimer > 4 microg/mL, AT activity < 79%, TAT > 26 ng/mL, and PIC > 1.2 microg/mL. Particularly, deltaPlt and D-dimer are useful bedside predictive markers in order to decide the optimal time for the termination of pregnancy in patients with severe preeclampsia.

Abortion, Therapeutic↗

PubMed2001

DNA sequence analysis of protein S deficiency--identification of four point mutations in twelve Japanese subjects.

The molecular basis for the hereditary type I protein S (PS) deficiency was investigated. DNA sequence analysis of 12 patients with PS deficiency in Japan identified four point mutations and three of them were novel. Nonsense mutations found in two unrelated patients resulted in termination of the PS polypeptide chains at Gln 238 and Lys 392, respectively. Two novel missense mutations were also found in two other patients substituting Asp 202 for Asn and Leu 298 for Pro, respectively. Comparison of the PS amino acid sequences from several mammalians indicated that Asp 202 and Leu 298 were preserved and thus appeared to be responsible for the pathogenesis of PS deficiency.

Humans↗

PubMed2001

Local cold stress to the soles induces retroplacental hemorrhage in rats.

The aim of this study was to investigate the effect of local cold stress to the soles on placental histology in rats. Pregnant rats were subjected to a cold provocation (0 degrees C, 12 degrees C) and room temperature (23 degrees C) for 15 and 30 minutes. During cold stimulation and at the control temperature, uterine blood flow and uterine contraction were measured simultaneously. Histological studies of the placentas of these rats were also performed. Cold stress at 0 degrees C and 12 degrees C significantly decreased uterine blood flow (P < .005, P < .02) compared with controls (23 degrees C). The decrease in uterine blood flow was greater at 0 degrees C than at 12 degrees C stress. Cold-induced stress (0 degrees C) also evoked an isometric tension with increased frequency and amplitude in the rat uterus (P < .003, P < .0002) compared with controls (23 degrees C). Stimulation at 12 degrees C did not induce any uterine contractions. Placental histology of rats stressed at 0 degreesC revealed hemorrhages into the decidua basalis. These findings suggest that local cold stress decreases uterine blood flow and increases uterine contraction, resulting in retroplacental hemorrhage in rats. This model may account for human abruptio placentae.

Animals↗

PubMed2001

Restoration of immunocyte functions by thymosin alpha1 in cyclophosphamide-induced immunodeficient mice.

Thymosin alpha1 (Talpha1) is an oligopeptide hormone originally isolated from the thymus gland, and has been reported to have stimulating effects on the differentiation of T cells and NK cells. These immunostimulating properties have been considered to be useful for improving immune disorders associated with various diseases including cancer, AIDS and hepatitis. Here, we characterized immunostimulating properties of Talpha1 in experimental immunodeficiency of mice that was induced by the administration of cyclophosphamide (CY). Repeated injection of 30-300 microg/kg/day of Talpha1 after CY-treatment significantly accelerated the restoration of the reduced number of CD4+CD8+ T cells in the thymus. Talpha1 administration was effective in restoring the suppressed activities of helper T cells and cytotoxic T cells in CY-treated mice. Talpha1 also had stimulating effects on reduced activity of lymphokine-activated killer cells in CY-treated mice. These results indicate that Talpha1 is stimulatory for both humoral and cellular immune responses, thus providing the immunological basis for the clinical benefit of this compound.

Animals↗

PubMed2001

A case of glassy cell carcinoma of the uterine cervix effectively responding to chemotherapy with paclitaxel and carboplatin.

Glassy cell carcinoma (GCC) of the uterine cervix is a highly malignant tumor and has a poor prognosis. As yet, no effective systemic chemotherapy to this tumor has been reported. Here we describe a case of recurrent GCC that responded to paclitaxel and carboplatin combination treatment. The patient, a 32-year-old woman, with clinical staging FIGO IB1 disease had a radical hysterectomy and postoperative radiotherapy. Three months after initial treatment, she had a relapse as peritoneal dissemination, which was confirmed in the second surgery (adnectomy) and which did not respond to platinum-based conventional chemotherapy (cisplatin, adriamycin, cyclophosphamide and carboplatin, etoposide). The recurrent peritoneal tumors responded well to paclitaxel and carboplatin combination treatment. An elevated serum concentration of carcinoembryonic antigen (672 ng/ml) was reduced to 14.4 ng/ml by six such courses. Peritoneal histopathology confirmed a complete response in the third surgery (ileostomy) for adhesive ileus by the radiotherapy. This is the first report of effective systemic chemotherapy with paclitaxel and carboplatin to recurrent GCC of the uterine cervix.

Adult↗