[Show abstract][Hide abstract] ABSTRACT: We employ observations obtained from a meteor wind radar to derive ambipolar diffusion coefficients, neutral temperatures, temperature gradients and, subsequently, Brunt-Väisälä frequencies at an altitude of 90 km over Svalbard (78°N, 16°E). The derived values showed a good agreement with independent measurements at each step of the analysis. Current atmospheric models are based on sparse data obtained at such high latitude, so these results represent a viable alternative for incorporating in subsequent studies of atmospheric dynamics, particularly if the derived monthly variabilities are included. The Brunt-Väisälä frequencies are then combined with wind shear measurements to estimate horizontally averaged gradient Richardson Numbers (Ri). We find Ri to be consistently larger in summer than winter due to wind shears being similarly larger in winter and augmented by the inverse seasonal variation in Brunt-Väisälä frequency. These seasonal variations result in Ri indicative of dynamic stability in summer and instability in winter. The variabilities in wind shear and Brunt-Väisälä frequency are then included to - albeit more qualitatively - illustrate the distribution between stability and static and dynamic instabilities as a function of season, using a novel portrayal pioneered by Zink and Vincent (J. Geophys. Res., 109, doi:10.1029/2003JD003992, 2004). The resulting picture is discussed in the framework of current conceptions of distribution of turbulent energy dissipation with height and season and of current opinion of the mesopause structure at 78°N.
Preview · Article · Mar 2007 · Earth Planets and Space
[Show abstract][Hide abstract] ABSTRACT: l-Arginine is the common substrate for arginase and nitric oxide synthase (NOS). Arginase converts l-arginine to urea and ornithine, which is the principal precursor for production of polyamines required for cell proliferation. Human placenta expresses endothelial NOS (eNOS) in syncytiotrophoblasts, but the expression of arginase has not been fully elucidated. Our aim was to investigate the expression and distribution patterns of arginase-I (A-I) and arginase-II (A-II) in human placental villi in the first trimester and at term using immunohistochemistry, RT-PCR and Western blot analysis. The arginase enzyme activity in placental villi was also measured. Immunohistochemistry showed different distribution patterns of the arginase isoforms during gestation: A-I was observed only in cytotrophoblasts, while A-II was observed in both cytotrophoblasts and syncytiotrophoblasts. RT-PCR and Western blot analysis showed expression of A-I and A-II in the first trimester and at term in human placental villi. Expression of A-II and arginase activity was greater in the first trimester than at term. Differentiation of cytotrophoblasts into syncytiotrophoblasts may be associated with l-arginine metabolism through modulation of l-arginine availability for eNOS and A-I. And elevated arginase activity in the early gestational period may be responsible for proliferation of trophoblasts by increasing polyamines production. These results suggest that the l-arginine-ornithine-polyamine and l-arginine-nitric oxide pathways play a role in placental growth and development.
[Show abstract][Hide abstract] ABSTRACT: Abstract The aim of the present study was to investigate changes in emotional state and the relationship between emotional state and demographic/clinical factors and coping style among gynecologic patients undergoing surgery. Using the Japanese version of the Profile of Mood States (POMS), 90 patients (benign disease: 32, malignancy: 58) were examined on three occasions: before surgery, before discharge, and 3 months after discharge. They were also examined using the Coping Inventory for Stressful Situations (CISS) on one occasion before discharge. The scores for the subscales depression, anger, and confusion were the highest after discharge while those for anxiety were the highest before surgery. The average scores of the POMS subscales for all subjects were within the normal range. With regard to the relationship between these emotional states and other factors, multiple regressions showed that the principal determinants of anxiety before surgery were religious belief, psychological symptoms during hospitalization and emotion-oriented (E) coping style; further, it was found that depression after discharge could be explained by chemotherapy, duration of hospitalization, and E coping style. The principal determinants of anger after discharge and vigor before surgery were length of education and E coping style, and severity of disease, chemotherapy, E coping style and task-oriented coping style, respectively. Those of post-discharge fatigue and confusion were length of education, psychological symptoms, and E coping style. In summary it is suggested that the following should be taken into account in patients undergoing gynecologic surgery: anxiety before surgery, depression, anger, and confusion after surgery, including coping styles.
Full-text · Article · Jan 2007 · Psychiatry and Clinical Neurosciences
[Show abstract][Hide abstract] ABSTRACT: 1] A function that approximates atmospheric tidal behavior in the polar regions is described. This function is fitted to multistation radar measurements of wind in the mesosphere and lower thermosphere with the aim of obtaining a latitude-longitude-height description of the variation of tides over the whole Antarctic continent. Archival wind data sets are combined with present-day ones to fill the spatial distribution of the observations and to reduce the potential effects of spatial aliasing. Multiple years are combined through the compilation of monthly station composite days, yielding results for each month of the year. Despite potential problems associated with year-to-year variations in the tidal phase, a useful climatology of Antarctic zonal and meridional tidal wind components is compiled. The results of the fits reproduce the major features of the high-latitude tidal wind field: the dominance of the semidiurnal migrating mode in the winter months and the presence of a semidiurnal zonal wave number one component in the summer months. It is also found that the summer semidiurnal tide contains a zonal wave number zero component.
Full-text · Article · Dec 2006 · Journal of Geophysical Research Atmospheres
[Show abstract][Hide abstract] ABSTRACT: Dysembryoplastic neuroepithelial tumor is a rare, low-grade brain tumor that is characterized by intractable, partial seizures of juvenile onset.
A 36-year-old pregnant woman with dichorionic, diamniotic twins temporarily lost consciousness at 27 weeks of gestation. Magnetic resonance imaging evaluation showed a 3-cm multicystic nodule in her right temporal lobe that was diagnosed, together with her history of recurrent anxiety attacks, as dysembryoplastic neuroepithelial tumor. The lesion did not enlarge during pregnancy, and healthy male infants were delivered by cesarean at 36 weeks. The tumor was successfully removed 2 months postpartum, and the patient has experienced no further seizures.
Dysembryoplastic neuroepithelial tumor was conservatively managed during pregnancy without neurosurgical intervention.
No preview · Article · Oct 2006 · Obstetrics and Gynecology
[Show abstract][Hide abstract] ABSTRACT: To clarify the role of GATA transcription factors in ovarian carcinogenesis, we analyzed the expression and methylation states of GATA-4/-5/-6 in eight human ovarian cancer cell lines. GATA-4/-5 were methylated in three and two cell lines without their expression, respectively. Methylation of GATA-4/-5 was also detected in nine and five of 15 primary ovarian cancers, respectively. GATA-6 was not methylated in any cases. We transiently over-expressed GATA-5 in the JHOC-5 cell line using an adenovirus system, resulting in that apoptosis was induced and apoptosis-related genes, such as Apaf-1, were up-regulated. These data suggest that GATA-4/-5 may be involved in ovarian carcinogenesis.
[Show abstract][Hide abstract] ABSTRACT: This study was designed to investigate the role of arginase in regulating myometrial contractions during gestation in the rat. Arginase activity in the myometrium was significantly decreased during the 7th-21st day of gestation, with the lowest value on the 14th day. However, the enzyme activity became significantly higher at term gestation (22nd day) than that in the non-pregnant myometrium. Arginase I protein was undetectable in the non-pregnant myometrium, at 7th and 14th day of gestation and after delivery. A slight positive signal for arginase I was detectable at 21st day of gestation. However, the protein was clearly up-regulated at term gestation (22nd day), although arginase II protein was down-regulated during gestation, with the lowest value on the 14th day. Gestational changes in arginase activity negatively correlated with those in cyclic GMP production, whereas the changes positively correlated with those in endogenous nitric oxide synthase (NOS) inhibitors and endothelin-1 (ET-1) contents. Myometrial arginase activity was inhibited by N(G)-hydroxy-L-arginine as an intermediate of NO production from L-arginine in a concentration-dependent manner. Both basal and stimulated guanylyl cyclase activities were enhanced at mid- and reduced at term gestation and after delivery, thereby partly increasing cyclic GMP production at mid- and partly decreasing the nucleotide production at term gestation and after delivery. These results suggest that the decreased arginase activity at mid-gestation possibly results from the down-regulation of arginase II protein. Whereas, the enhanced overall arginase activity at term gestation seems to be because of the induced functional arginase I in concert with the attenuated arginase II expression. The enhanced arginase activity at term gestation would be implicated in increasing myometrial contractions mediated by the increased ET-1. The increased peptide production at term gestation is possibly because of the reduced cyclic GMP production resulting from enhanced arginase activity, accumulated endogenous NOS inhibitors and attenuated guanylyl cyclase activity.
Preview · Article · Sep 2006 · Molecular Human Reproduction
[Show abstract][Hide abstract] ABSTRACT: A brief ischemia causes delayed neuronal death (DND) in some areas vulnerable to ischemia. Additionally, it causes a transient reduction in the apparent diffusion coefficients (ADCs) obtained from diffusion-weighted magnetic resonance imaging (DWI), which is a powerful tool to detect ischemic changes in the brain at a very early stage. The present study examined long-term histopathological changes in the hippocampal neurons up to 30 days after a very mild hypoxic-ischemic (HI) insult in immature rats. Three-week-old male rats were subjected to 15- and 30-min HI insults (15-min HI and 30-min HI) and serial DWI was performed. Only animals whose ADC reduction pattern was transient were examined histopathologically. ADCs decreased significantly during the insult, and the ADC values of 30-min HI group were significantly lower than those of 15-min HI group. Ischemic neuronal changes were observed up to 30 days after the insult in 30-min HI group, although ADCs in the chronic stage were within the normal range. In addition, neuron density in 30-min HI group was significantly lower in the chronic stage (on days 14 and 30) than in 15-min HI group. A very mild hypoxia-ischemia followed by a transient ADC reduction causes persistent neuronal death, which can be predicted by measuring ADCs during the acute insult.
[Show abstract][Hide abstract] ABSTRACT: Meteor radars are employed to determine neutral air temperatures at 90 km altitude above Adventdalen, Spitsbergen (78°N, 16°E) and Ramfjordmoen, mainland Norway (70°N, 19°E). The philosophy underlying the temperature derivation including choice of appropriate pressure model and calibration against independent observations is discussed. Average annual variations at each of the two geographic locations are presented, indicating that current models overestimate the summer temperatures by as much as 20 K. The seasonal variation of variability of these temperatures, indicative of corresponding variation in planetary wave activity, is investigated, and in particular, we see that wave activity at 78°N is largely suppressed during summer and is otherwise characterized by a quasi 27-day oscillation during late autumn and winter. The monthly average temperatures for 78°N presented here are proposed as a viable alternative to current semiempirical models.
Full-text · Article · Jul 2006 · Journal of Geophysical Research Atmospheres
[Show abstract][Hide abstract] ABSTRACT: The present study investigated the activity of the autonomic nervous system (ANS), a major influence in normal physiological function, and its association with unfavorable postmenopausal states in body composition, lipid and/or glucose metabolism, or cardiovascular profiles. Body composition, blood pressure, and blood profiles of lipid and glucose of 175 postmenopausal women were measured. Resting ANS activity was assessed by heart rate variability (HRV) power spectral analysis. To scrutinize the influence of ANS activity levels on postmenopausal obesity-related factors, we divided the subjects into a low group ( < 220 ms(2)) and a high group ( > 220 ms(2)), based on the total power of HRV. Low-frequency (P < 0.01) and high-frequency power (P < 0.01) were both significantly lower in the low group. No significant difference was found in age, age at menopause, or years after menopause between the two groups. In contrast, body mass index (P < 0.05), percentages of body fat (P < 0.01), and systolic (P < 0.01) and diastolic (P < 0.01) blood pressure were significantly greater in the low group. As to blood lipid profiles, triglycerides (P < 0.05), total cholesterol (P < 0.05), and low-density lipoprotein cholesterol (P < 0.05) were significantly higher in the low group. Our findings indicate that reduced sympatho-vagal activity is associated with higher postmenopausal body fat content, blood pressure, and blood lipid concentrations. This study further implies that such autonomic depression could be a crucial risk factor in undermining the health and, ultimately, the quality of life, of postmenopausal women.
No preview · Article · Jul 2006 · Arbeitsphysiologie
[Show abstract][Hide abstract] ABSTRACT: Present experiments were designed to investigate the effects of ovariectomy (OVX) and estrogen replacement (ER) on neointimal formation after balloon injury of the rat carotid artery. Young adult female rats were divided into 3 groups of sham operation (control), ovariectomy, and ovariectomy plus estrogen replacement. Estrogen replacement was initiated by implanting a sustained release pellet containing water-soluble 17beta-estradiol 1 week after the ovariectomy. Carotid arteries were harvested 2 weeks after the balloon injury for determinations. The balloon injury caused intimal hyperplasia, which was accompanied by the impaired endothelium-dependent relaxation and cyclic GMP production, and accumulation of asymmetric dimethylarginine (ADMA) as an endogenous NOS inhibitor. Bilateral ovariectomy accelerated the intimal hyperplasia. The acceleration was accompanied by the enhanced impairment of NO production, attenuated reendothelialization, and enhanced accumulation of ADMA. The estrogen replacement improved the accelerated intimal hyperplasia with concomitant improvement of the impaired NO production and accumulated asymmetric dimethylarginine, and facilitated reendothelialization. These results suggests that the enhanced impairment of NO production, which possibly results from the accumulated asymmetric dimethylarginine and lack of reendothelialization, may contribute to the acceleration of intimal hyperplasia by ovariectomy and that estrogen replacement effectively improves the intimal hyperplasia by restoring the impaired NO production through reducing endogenous NOS inhibitor and facilitating reendothelialization.
No preview · Article · Feb 2006 · Journal of Cardiovascular Pharmacology
[Show abstract][Hide abstract] ABSTRACT: Kinetic energy dissipation rates for the auroral MLT have been obtained from the Tromsø middle frequency radar (MFR) and compared with simultaneous measurements of neutral wind-shears obtained from the Nippon/Norway Tromsø meteor radar (NTMR). Since wind-shears can drive dynamic instabilities which in turn result in turbulent dissipation of kinetic energy, we would expect these parameters to be correlated, and this is indeed the case. Having established this correlation we quantitatively combine the results from each radar to estimate the turbulent diffusion coefficient for momentum; considering the tentative nature of this approach, we find the agreement with previous estimates to be surprisingly good.
No preview · Article · Feb 2006 · Journal of Atmospheric and Solar-Terrestrial Physics
[Show abstract][Hide abstract] ABSTRACT: A few topics from recent developments of radio meteor observation
techniques are presented The Nippon Norway Tromsoe Meteor Radar NTMR has
been in continuous operation since November 2003 in Tromsoe 69N One of
the major advantages of the present meteor radar is its high echo rate
6000-20000 echoes a day despite the relatively small transmitting power
7 5kW peak From ambipolar diffusion coefficients we have successfully
extracted atmospheric temperature fluctuations due to gravity waves
assuming the Boussinesq approximation The time and height resolutions of
horizontal winds and temperature fluctuations at the altitude of 90 km
are 1 hour and 2km high enough for the study of gravity waves with a
period longer than a few hours Horizontal propagation characteristics of
gravity waves are further studied using a theoretical phase relation
between the wind and temperature fluctuations MST radars in the VHF band
have a great potential in meteor echo observations due to their high
transmitting power The meteor measurement can be conducted throughout a
day and complement the turbulent echo measurement in the mesosphere
which is limited to daylight hours only The MU radar of Kyoto University
is one of those radars and has been successfully applied to meteor
studies by utilizing its very high versatility The MU radar was recently
renewed Its signal processing unit is up-graded from a 4 analog receiver
system to a 25 digital receiver system In the present study we try to
improve the MU radar meteor measurement
[Show abstract][Hide abstract] ABSTRACT: Most preterm deliveries are associated with infection and inflammation. Prostaglandin E2 (PGE2) is one of the most important mediators in the processes of inflammation, and is converted from PGH2 by various kinds of PGE synthases (PGESs). Among PGESs, microsomal PGES-1 (mPGES-1) is known to be the most important subtype in the processes of inflammation. To evaluate the role of PGESs in preterm delivery, we used mPGES-1 knockout mice in a lipopolysaccharide (LPS)-induced preterm labor model. Unexpectedly, the duration of labor after LPS treatment was not statistically different between C57BL6 wild-type mice and mPGES-1 knockout mice. In wild-type mice, mPGES-1 mRNA and protein expression increased in the myometrium and fetal membrane after LPS treatment. In contrast, the expression of mPGES-2 or cytosolic PGES was not changed by LPS treatment. On mPGES-1 knockout mice, mPGES-2 increased by LPS treatment in myometrium. The present data indicate that mPGES-1 may be involved in LPS-induced preterm labor, but inhibition of mPGES-1 alone may not prevent preterm delivery, because mPGES-2 might compensate for the role of mPGES-1.
Preview · Article · Jan 2006 · Journal of Endocrinology
[Show abstract][Hide abstract] ABSTRACT: In order to examine the dynamics of Antarctic ozone hole dissipation processes an intensive observation was performed using ozonesondes at Syowa Station 39 6 degree E 69 0 degree S in June 2003 through January 2004 when the ozone hole was developed into the second largest in the past Ninety two vertical profiles of ozone were successfully obtained Observed ozone partial pressure increased earlier at higher altitudes in the dissipation phase of the ozone hole which is marked contrast with the developing phase when it decreased almost simultaneously in the ozone layer at altitudes of 14--21 km The earlier ozone recovery at higher altitudes started already in late August indicating the importance of downward transport by diabatic circulation Thus our analysis is focused on the descent rate of a level of a particular ozone mixing ratio 1 0 ppmv around 20 km for a time period of late September through late October before the polar vortex was broken Using satellite data by ILAS-II distributed at many longitudes in the Antarctic it is shown that the descent rate of ozone is not constant zonally in the polar vortex but modified significantly by a dominant quasi-stationary planetary wave This result suggests that downward transport across the isentropes is faster in particular regions with warm anomaly where the radiative cooling acts effectively An analysis is extended to the ILAS-II data of N 2 O as a long-lived species The mean descent rate around 20 km N 2 O mixing ratio of 60 ppbv is 1 6 km month -1 which is only half that of ozone 2 3 km
[Show abstract][Hide abstract] ABSTRACT: The first results of long-term meteor observations made with Syowa MF radar (69°S, 39°E), Antarctica, are presented. In winter, meteor wind measurements can be conducted throughout the day without being severely affected by group retardation or total reflection, while in summer the observations are confined within several hours around 0000 local time (LT). Daily meteor echo rates (roughly 300–1000) are clearly anticorrelated with local K indices, indicating that the observations mostly represent geomagnetically quiet conditions. Echoes are distributed from around 80 km to 120 km, with the peak altitude at around 100 km. The maximum height is set by the relatively slow sampling frequency employed (5 Hz) and is expected to be extended by using a higher frequency. Meteor and full correlation analysis (FCA) winds in winter months are compared. They agree well at around 90 km, while the FCA winds tend to underestimate the meteor winds at upper altitudes. A notable finding is that the directions of wind velocities can also be different. The FCA winds show less height variations above about 90 km and it appears as though the FCA heights are overestimated. A case study of angles of arrival estimated from MF echoes suggests a possibility that meteor echoes contaminate ionospheric echoes down to as low as 80 km. However, quantitative evaluation of meteor contamination effects, if any, on FCA wind velocities has not been done yet and remains a future topic to be studied. Other sources which cause the differences should also be sought. The remarkably wide height coverage of the present MF radar observations (from around 60 to nearly 120 km) using both FCA and meteor techniques simultaneously will greatly contribute to polar mesosphere and lower thermosphere study.
Preview · Article · Dec 2005 · Journal of Geophysical Research Atmospheres
[Show abstract][Hide abstract] ABSTRACT: Simultaneous European Incoherent Scatter (EISCAT) radar observations using two EISCAT radars, the Tromsø (69.6°N, 19.2°E) UHF radar and the EISCAT Svalbard radar (Longyearbyen, 78.2°N, 16.0°E), were conducted for 8 consecutive days, from 11 to 19 November 2003, to study the lower thermospheric wind dynamics in the polar region. Altitude profiles of the amplitudes of the diurnal and semidiurnal components at Tromsø and Longyearbyen are similar. The semidiurnal amplitudes in the meridional and zonal components exhibit maxima at 105–107 km, with values of ∼70–90 m s−1. The semidiurnal phases vary with roughly a 30 km vertical wavelength between 98 and 110 km. The quasi-2 day wave (Q2DW) was not detected in the lower thermosphere at either Tromsø or Longyearbyen during the period, while it was found between 70 and 82 km in the mesosphere with the colocated Tromsø MF radar. This observational result suggests that in general, the Q2DW attenuates in the mesosphere and cannot penetrate into the lower thermosphere in winter. Ion drag acceleration of the wind is generally negligible below 107 km at Tromsø and below 118 km at Longyearbyen, but significant ion drag acceleration is found above these heights. A comparison of mean wind and tidal amplitudes and phases with National Center for Atmospheric Research Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model predictions for the period shows some agreement.
No preview · Article · Dec 2005 · Journal of Geophysical Research Atmospheres
[Show abstract][Hide abstract] ABSTRACT: The Shinshu University Sodium lidar has conducted 3-year temperature observation in Antarctica from 2000 to 2002. Coupling with simultaneous wind observation with MF/meteor radar (1999-2004) in the mesopause region, we report the wind and temperature feature concerning the Antarctic sudden stratospheric warming event in 2002. The lidar temperature from July to September in 2002 showed as much as 20K higher than those of previous two years. In the corresponding period, eastward wind at 80 km (104 km) in 2002 was close to zero (+10 m/s) though the winds of previous years shows +20 m/s (2-3 m/s). Northward wind in 2002 showed +5 m/s at 80 km and -10 m/s at 104 km, though the corresponidng wind velocities were -5 m/s and +2-3 m/s in previous years. The downward propagation of temperature drop was observed in August with the velocity of 1 km/day.
[Show abstract][Hide abstract] ABSTRACT: We examined the involvement of nitric oxide (NO) and/or endothelium-derived hyperpolarizing factor (EDHF) in decreasing peripheral vascular resistance in the rat hind limb perfusion model and analyzed the identity of EDHF in this model. The potency of carbachol (CCh) to produce relaxation was quantitatively similar to sodium nitroprusside (SNP). CCh-induced relaxation was abolished after endothelial denudation, but resistant to nitroarginine and indomethacin. The relaxation was inhibited by tetraethylammonium, ouabain, charybdotoxin plus apamin, and under depolarization. SNP-induced relaxation was accompanied by increased cGMP production, which was inhibited by ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-l-one). Although CCh produced a similar extent of relaxation to SNP, the cGMP level was 24 times lower than that with SNP. Low KCl produced a definite relaxation, which was inhibited by ouabain, but independent of NO, prostacyclin, and endothelium. 1-EBIO (1-ethyl-2-benzimidazolinone) as an activator of IK(Ca) channel also produced a concentration-dependent relaxation, which was inhibited by charybdotoxin, ouabain, and depolarization, but independent of NO and prostacyclin. Clotrimazole and 17-octadecynoic acid as inhibitors of P(450) monooxygenase inhibited the CCh-induced relaxation. Meanwhile, catalase at a concentration sufficient to inhibit H(2)O(2)-induced relaxation did not exert definite inhibition of the CCh-induced relaxation. These results suggest that CCh produces an endothelium-dependent, EDHF-dependent, and NO-cGMP-independent relaxation and that K(+) and metabolite(s) of P(450) monooxygenase possibly play an important role for this relaxation.
No preview · Article · Aug 2005 · Journal of Pharmacological Sciences