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Search Results: 1 - 10 of 683 matches for " Maki Nakata "
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Pelvic floor function and advanced maternal age at first vaginal delivery  [PDF]
Mikako Yoshida, Ryoko Murayama, Maki Nakata, Megumi Haruna, Masayo Matsuzaki, Mie Shiraishi, Hiromi Sanada
Open Journal of Obstetrics and Gynecology (OJOG) , 2013, DOI: 10.4236/ojog.2013.34A005
Abstract:

Purpose: The study aimed to show differences in temporal recovery of pelvic floor function within 6 months postpartum between women having their first delivery at an advanced age and those having their first delivery at a younger age. Methods: Seventeen women (age: 35.5 ± 3.5, BMI: 21.1 ± 3.2) were studied at about 6 weeks, 3 months, and 6 months after vaginal delivery. Urinary incontinence was assessed by the International Consultation on Incontinence Questionnaire-Short Form. Pelvic floor function was assessed by the anteroposterior diameter of the levator hiatus using transperineal ultrasound. Women who delivered for the first time at 35 years and/or older were defined as being of advanced maternal age. Results: Nine of 17 women (52.9%) were of advanced maternal age and 5 experienced postpartum stress urinary incontinence. Four of these 5 women (80.0%) were of advanced maternal age. The anteroposterior diameter of the levator hiatus at rest was significantly greater in the advanced maternal age women than in the younger maternal age women at 3 and 6 months postpartum (p < 0.01). Among the continent women, the anteroposterior diameter of the levator hiatus at rest was significantly greater in the advanced maternal age women than in the younger maternal age women at 6 months postpartum (p = 0.004). However, among the advanced maternal age women, all parameters of the anteroposterior diameter of the levator hiatus were not significantly different between the women with and without stress urinary continence. Conclusion: Recovery of pelvic floor function following delivery may be delayed in women of advanced maternal age at first delivery because of the damage to the pelvic floor during pregnancy and vaginal delivery, resulting in increase in the incidence of stress urinary incontinence.

In Vivo Analysis of Aicda Gene Regulation: A Critical Balance between Upstream Enhancers and Intronic Silencers Governs Appropriate Expression
Le Thi Huong, Maki Kobayashi, Mikiyo Nakata, Go Shioi, Hitoshi Miyachi, Tasuku Honjo, Hitoshi Nagaoka
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0061433
Abstract: The Aicda gene encodes activation-induced cytidine deaminase (AID). Aicda is strongly transcribed in activated B cells to diversify immunoglobulin genes, but expressed at low levels in various other cells in response to physiological or pathological stimuli. AID’s mutagenic nature has been shown to be involved in tumor development. Here, we used a transgenic strategy with bacterial artificial chromosomes (BACs) to examine the in vivo functions of Aicda regulatory elements, which cluster in two regions: in the first intron (region 2), and approximately 8-kb upstream of the transcription start site (region 4). Deleting either of these regions completely abolished the expression of Aicda-BAC reporters, demonstrating these elements’ critical roles. Furthermore, we found that selectively deleting two C/EBP-binding sites in region 4 inactivated the enhancer activity of the region despite the presence of intact NF-κB-, STAT6- and Smad-binding sites. On the other hand, selectively deleting E2F- and c-Myb-binding sites in region 2 increased the frequency of germinal-center B cells in which the Aicda promoter was active, indicating that E2F and c-Myb act as silencers in vivo. Interestingly, the silencer deletion did not cause ectopic activation of the Aicda promoter, indicating that Aicda activation requires enhancer-specific stimulation. In summary, precise regulation of the Aicda promoter appears to depend on a coordinated balance of activities between enhancer and silencer elements.
Properties of Time-Varying Causality Tests in the Presence of Multivariate Stochastic Volatility  [PDF]
Daiki Maki
Open Journal of Statistics (OJS) , 2016, DOI: 10.4236/ojs.2016.65064
Abstract: This paper compares the statistical properties of time-varying causality tests when errors of variables have multivariate stochastic volatility (SV). The time-varying causal-ity tests in this paper are based on a logistic smooth transition autoregressive model. The compared time-varying causality tests include asymptotic tests, heteroskedasticity-robust tests, and tests using wild bootstrap. Our simulation results show that asymptotic tests and heteroskedasticity-robust counterparts have size distortions under multivariate SV, whereas tests using wild bootstrap have better size properties regardless of type of error. In particular, the time-varying causality test with first-order Taylor approximation using wild bootstrap has better statistical properties.
Probing the evolution of early-type galaxies using multi-colour number counts and redshift distributions
Fumiaki Nakata,Kazuhiro Shimasaku,Mamoru Doi,Nobunari Kashikawa,Wataru Kawasaki,Yutaka Komiyama,Sadanori Okamura,Maki Sekiguchi,Masafumi Yagi,Naoki Yasuda
Physics , 1999, DOI: 10.1046/j.1365-8711.1999.03051.x
Abstract: We investigate pure luminosity evolution models for early-type (elliptical and S0) galaxies (i.e., no number density change or morphology transition), and examine whether these models are consistent with observed number counts in the B, I and K bands and redshift distributions of two samples of faint galaxies selected in the I and K bands. The models are characterized by the star formation time scale $\tau_{SF}$ and the time $t_{gw}$ when galactic wind blows in addition to several other conventional parameters. We find the single-burst model ($\tau_{SF}$=0.1 Gyr and $t_{gw}$=0.353 Gyr), which is known to reproduce the photometric properties of early-type galaxies in clusters, is inconsistent with redshift distributions of early-type galaxies in the field environment due to overpredictions of galaxies at $z\gsim1.4$ even with strong extinction which is at work until $t_{gw}$. In order for dust extinction to be more effective, we change $\tau_{SF}$ and $t_{gw}$ as free parameters, and find that models with $\tau_{SF}\gsim0.5$ Gyr and $t_{gw}>1.0$ Gyr can be made consistent with both the observed redshift distributions and number counts, if we introduce strong extinction $(E(B-V)\geq1$ as a peak value). These results suggest that early-type galaxies in the field environment do not have the same evolutionary history as described by the single-burst model.
Behaviors of Crystallization for Osmotic Pressure under Microwave Irradiation  [PDF]
Ryosuke Nakata, Yusuke Asakuma
Journal of Crystallization Process and Technology (JCPT) , 2015, DOI: 10.4236/jcpt.2015.51002
Abstract: We studied chemical garden in order to investigate precipitation behavior for osmotic pressure under microwave irradiation. The salt concentration and microwave irradiation power were varied. Microwave irradiation induced release of osmotic pressure and change of precipitation pattern because polar molecules vibrate and rotate in an electromagnetic field. For example, the width of precipitation increased and the number of rapture of the membrane decreased due to the release of osmotic pressure by the irradiation. Accordingly, microwave irradiation accelerated the diffusion of ionic molecules through the membrane.
Clustering Properties of Galaxies at z~4 in the Subaru/XMM Deep Survey Field
Masami Ouchi,Kazuhiro Shimasaku,Sadanori Okamura,Mamoru Doi,Hisanori Furusawa,Masaru Hamabe,Masahiko Kimura,Yutaka Komiyama,Masayuki Miyazaki,Satoshi Miyazaki,Fumiaki Nakata,Maki Sekiguchi,Masafumi Yagi,Naoki Yasuda
Physics , 2001, DOI: 10.1086/323598
Abstract: We study the clustering properties of about 1200 z~4 Lyman Break Galaxy (LBG) candidates with i'<26 which are selected by color from deep BRi' imaging data of a 618 arcmin^2 area in the Subaru/XMM-Newton Deep Field taken with Subaru Prime Focus Camera. The contamination and completeness of our LBG sample are evaluated, on the basis of the Hubble Deep Field North (HDFN) objects, to be 17% and 45%, respectively. We derive the angular correlation function over theta = 2''-1000'', and find that it is fitted fairly well by a power law, omega(theta)=A_omega theta^{-0.8}, with A_omega = 0.71 +/- 0.26. We then calculate the correlation length r0 (in comoving units) of the two-point spatial correlation function xi(r) = (r/r0)^{-1.8} from A_omega using the redshift distribution of LBGs derived from the HDFN, and find r0=2.7 (+0.5/-0.6) h^{-1} Mpc in a Lambda-dominated universe (Omega_m=0.3 and Omega_Lambda=0.7). This is twice larger than the correlation length of the dark matter at z~4 predicted from an analytic model by Peacock & Dodds but about twice smaller than that of bright galaxies predicted by a semi-analytic model of Baugh et al. We find an excess of omega(theta) on small scales (theta < 5'') departing from the power law fit over 3 sigma significance levels. Interpreting this as due to galaxy mergers, we estimate the fraction of galaxies undergoing mergers in our LBG sample to be 3.0 +/- 0.9%, which is significantly smaller than those of galaxies at intermediate redshifts.
Statistical Properties of Lyman Break Galaxies at z~4
Masami Ouchi,Kazuhiro Shimasaku,Sadanori Okamura,Mamoru Doi,Hisanori Furusawa,Masaru Hamabe,Masahiko Kimura,Yutaka Komiyama,Masayuki Miyazaki,Satoshi Miyazaki,Fumiaki Nakata,Maki Sekiguchi,Masafumi Yagi,Naoki Yasuda
Physics , 2001,
Abstract: We study the luminosity function and the correlation function of about 1200 z~4 Lyman break galaxies (LBGs) with i'<26 that are photometrically selected from deep BRi' imaging data of a 618 arcmin^2 area in the Subaru/XMM-Newton Deep Field taken with Subaru Prime Focus Camera. The contamination and completeness of our LBG sample are evaluated, on the basis of the Hubble Deep Field-North (HDF-N) objects, to be 17% and 45%, respectively. We derive the UV (rest 1700A) luminosity functions (LFs) and find a large population of UV-luminous galaxies at z~4. The LFs of the red and blue subsamples imply that the bright LBGs are redder in the UV continuum than the average color of the LBGs. Then we calculate the correlation function over theta = 2''-1000'' and find that it is fitted fairly well by a power law, omega(theta)=A_omega theta^(-0.8), with A_omega=0.71 +/- 0.26. We estimate the correlation length r_0 (in comoving units) of the two-point spatial correlation function xi(r) = (r/r_0)^(-1.8) to be r_0=2.7 +0.5/-0.6 h^(-1) Mpc (Omega_m=0.3 and Omega_Lambda=0.7). The correlation function shows an excess of omega (theta) on small scales (theta < 5''), departing from the power-law fit at > 3 sigma significance level. Interpreting this as being due to galaxy mergers, we evaluate the fraction of galaxies undergoing mergers to be 3.0 +/- 0.9%, which is significantly smaller than those of galaxies at intermediate redshifts.
Angiotensinogen Expression Is Enhanced in the Progression of Glomerular Disease  [PDF]
Maki Urushihara, Hiroyuki Kobori
International Journal of Clinical Medicine (IJCM) , 2011, DOI: 10.4236/ijcm.2011.24064
Abstract: Intrarenal renin-angiotensin system (RAS) activation plays a critical role in the development and progression of renal injury. In the kidney, all of the RAS components are present and intrarenal angiotensin II (Ang II) is formed by multiple independent mechanisms. Angiotensinogen (AGT) is the only known substrate for renin that is a rate-limiting enzyme of the RAS. Recently, enhanced intrarenal AGT levels have been shown to reflect the intrarenal RAS status in hypertension, chronic glomerular disease and diabetic nephropathy. In this review, we focus on AGT expression of the diseased glomeruli in the progression of glomerular disease. An anti-glomerular basement membrane nephritis rat model developed progressive proteinuria and glomerular crescent formation, accompanied by increased macrophage infiltration and glomerular expression of AGT and Ang II. The addition of Ang II type 1 receptor blocker to CC-chemokine recaptor 2 antagonist markedly attenuated the induction of macrophage infiltration, AGT and Ang II, and reduced glomerular crescent formation. Next, the levels of glomerular AGT expression and marker of reactive oxygen species in Zucker diabetic fatty (ZDF) obese rats were higher than those in ZDF lean rats. Hydrogen peroxide (H2O2) induced an increase in the AGT expression in primary rat mesangial cells. Furthermore, the H2O2-induced upregulation of AGT was inhibited by a mitogen-activated protein kinase kinase and a c-Jun N-terminal kinase inhibitor. These data suggest the potential contribution of enhanced AGT expression in glomeruli to the intrarenal RAS activation for the development of glomerular disease.
Trends in age distribution of participants in a self-covered and a public expense-covered health check-up programs in Japan  [PDF]
Maki Ogawa, Atsushi Imai
Health (Health) , 2012, DOI: 10.4236/health.2012.49088
Abstract: Objective: In Japan, there are unique facilities (namely Ningen Dock) of health check-up, where asymptomatic participants undergo a medical examination at their own expense. The earlier occurrence of cervical cancer and the concern on screening prompted us compare to the age distribution in the self-covered system with that of free physical check-up programs at public expense. Methods: We analyzed medical records of Japanese women, who underwent gynecological examinations at self-covered expense and at public expense between for the periods 2002-2011 and 2005-2009, respectively, restricting examinee’s age group. Results: For self-covered system, approximately 80% of the overall examinee population was occupied with three age groups 30-39, 40-49 and 50-59. The participants was extremely fewer in the over 60 years age group accounting for 10%, compared to those for the public expense-covered system, the over 60 years age group being 25%. Participant under the age of 30 years seemed to increase in chronological order in both systems. Conclusion: The level of knowledge on sexually transmitted infections may contribute to screening promotion for the younger women, while the elderly over 60 years’ attitudes toward screening may be mainly related to social-economic status and/or public expense support.
Comparative Interactions of Anesthetic Alkylphenols with Lipid Membranes  [PDF]
Hironori Tsuchiya, Maki Mizogami
Open Journal of Anesthesiology (OJAnes) , 2014, DOI: 10.4236/ojanes.2014.412044
Abstract: Objective: While substituted phenols have a variety of pharmacological activity, the mechanism underlying their anesthetic effects remains uncertain especially about the critical target. We characterized the lipid membrane-interacting properties of different phenols by comparing with general anesthetic propofol and local anesthetics. Based on the results, we also studied the pharmacological effects possibly associated with their membrane interactivities. Methods: 1,6-Diphenyl-1,3,5-hexatriene-labeled lipid bilayer membranes were prepared with 1,2-dipalmitoyl-phosphatidylcholine as model membranes and with different phospholipids and cholesterol to mimic neuronal membranes. These membrane preparations were treated with phenols and anesthetics at 1 - 200 μM, followed by measuring the fluorescence polarization to determine the membrane interactivities to change membrane fluidity. Antioxidant effects were fluorometrically determined using diphenyl-1-pyrenylphosphine-incorporated liposomes which were treated with 10 - 100 μM phenols, and then peroxidized with 10 μM peroxynitrite. Results: Several phenols interacted with the model membranes and the neuronal mimetic membranes to increase their fluidity at 1 - 10 μM as well as lidocaine and bupivacaine did at 50 - 200 μM. Their comparative potencies were propofol > thymol > isothymol > guaiacol > phenol > eugenol, and bupivacaine > lidocaine, consistent with the rank order of neuro-activity. These phenols inhibited membrane lipid peroxidation at 10 and 100 μM with the potencies correlating to their membrane interactivities. Conclusion: The structure-specific membrane interaction is at least in part responsible for the pharmacology of anesthetic alkylphenols. Membrane-interacting antioxidant alkylphenols may be protective against the peroxynitrite-relating ischemia/reperfusion injury.
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