Developmental ability of trophoblast stem cells in uniparental mouse embryos

Neither parthenogenetic (PG) nor androgenetic (AG) mouse embryos survive after day 9.5 of pregnancy, owing to the inadequate growth of extraembryonic tissues, including the placenta. At day 9.5 of pregnancy, the placental structures are poorly developed in PG embryos, while trophoblast giant cells are abundant at the implantation site in AG embryos. These findings suggest that both parental genomes are required for placental development. To gain further insight into the trophoblast lineage in PG and AG embryos, we attempted to derive trophoblast stem (TS)-like cell lines from uniparental embryos. Furthermore, we sought to assess their ability to differentiate into cells of the trophoblast lineage by using gene expression analysis. Three cell lines that expressed marker genes for undifferentiated TS cells (Cdx2 and Errbeta) were derived from AG embryos. Under differentiation conditions, these cells expressed the trophoblast giant cell-specific genes, but did not express the spongiotrophoblast-specific genes. In contrast, none of the four cell lines from PG embryos expressed marker genes for undifferentiated TS cells, but they expressed Oct3/4, a marker gene for embryonic stem cells. Immunohistochemical analysis indicated that PG blastocysts expressed Oct3/4 and Cdx2 specifically in inner cell mass and the trophectoderm respectively. These results suggest that PG embryos do not possess TS cells, because of the lack of the developmental ability of trophoblast cells.

Phase-sensitive observation of a spin-orbital Mott state in Sr2IrO4

Measurement of the quantum-mechanical phase in quantum matter provides the most direct manifestation of the underlying abstract physics. We used resonant x-ray scattering to probe the relative phases of constituent atomic orbitals in an electronic wave function, which uncovers the unconventional Mott insulating state induced by relativistic spin-orbit coupling in the layered 5d transition metal oxide Sr2IrO4. A selection rule based on intra-atomic interference effects establishes a complex spin-orbital state represented by an effective total angular momentum = 1/2 quantum number, the phase of which can lead to a quantum topological state of matter.

Insulator-metal phase transition of Pr(0.6)Ca(0.4)MnO(3) studied by x-ray absorption spectroscopy in pulsed magnetic fields

Evolution of the Mn K-edge x-ray absorption near edge structure (XANES) in Pr(0.6)Ca(0.4)MnO(3) at pulsed magnetic fields has been investigated. A small enhancement of XANES spectra is detected across the magnetic-field-induced transition from the charge- and orbital-ordered (COO) insulator to ferromagnetic metal at 20 K. It is found that the magnetic-field dependence of the enhancement shows clear hysteresis, as seen in the magnetization with metamagnetic transition, suggesting a significant correlation between the change in the XANES and the field-induced collapse of the COO state. The enhancement of the absorption can be explained by an increase of the 4p density of states due to a reduction of hybridization between the 4p state of the central Mn ion with the core hole and the neighboring Mn 3d state. Local structural change around Mn ions is expected to modify the strength of the hybridization.

Control of the magnetoelectric domain-wall stability by a magnetic field in a multiferroic MnWO4

The relation between the orientation of the magnetic field and the flopped ferroelectric polarization has been investigated for multiferroic MnWO4. The ferroelectric single-domain state is retained across the polarization flop process when the direction of the applied magnetic field slightly deviates from the b axis within the ab plane. Furthermore, the electric polarization in the high-field P parallela phase is reversed when the P parallelb-to-P parallela transition takes place while decreasing and increasing the magnetic fields oppositely canted from the b axis. These results indicate that the symmetry breaking induced by a canted magnetic field determines the direction of the polarization flop, which corresponds to the direction of the vector spin chirality. The stability of the magnetoelectric domain walls in a canted magnetic field play a key role in the directional control of the electric polarization flop phenomenon.

Evidence for an electric-dipole active continuum band of spin excitations in multiferroic TbMnO3

The wide range optical spectra on a multiferroic prototype TbMnO3 have been investigated to clarify the origin of spin excitations observed in the far-infrared region. We elucidate the full band structure, whose high energy edge (133 cm;{-1}) exactly corresponds to twice of the highest-lying magnon energy. Thus the origin of this absorption band is clearly assigned to two-magnon excitation driven by the electric field of light. There is an overlap between the two-magnon and phonon energy ranges, where the strong coupling between them is manifested by the frequency shift and transfer of oscillator strength of the phonon mode.

Magnetic control of crystal chirality and the existence of a large magneto-optical dichroism effect in CuB2O4

The possibility of a magnetic field controlling the chirality of matter has been debated for a long time. Here, we report the successful induction of chirality in the noncentrosymmetric canted antiferromagnet, CuB2O4, by application of a low intensity static magnetic field. The chirality is reversed by a 90 degrees rotation of the direction of the magnetic field. The induction of chirality by a magnetic field gives rise to a gigantic enhancement of magnetochiral dichroism in this material. The ability to switch handedness in combination with this large magnetochiral optical effect allows us to design new optical devices such as a magnetically controllable isolator.

Cycloidal spin order in the a-axis polarized ferroelectric phase of orthorhombic perovskite manganite

The ferroelectric state in an orthorhombic perovskite RMnO3 (R=Gd0.7Tb0.3) was proved by neutron scattering studies to show the cycloidal spin state with the ab-spiral plane and the spin-helicity dependent polarization vector along the a axis, sharing the microscopic origin (inverse Dzyaloshinskii-Moriya interaction) with the more widely observed P||c state (e.g., for R=Tb and Dy) with the bc-spiral plane. The magnetic-field induced polarization flop from P||c to P||a as well known for RMnO3 is thus assigned to the orthogonal flop of the spin spiral plane from bc to ab.

Magnetic-field-induced ferroelectric state in DyFeO3

Versatile and gigantic magnetoelectric (ME) phenomena have been found for a single crystal of DyFeO3. Below the antiferromagnetic ordering temperature of Dy moments, a linear-ME tensor component as large as alphazz approximately 2.4 x 10(-2) esu is observed. It is also revealed that application of magnetic field along the c axis induces a multiferroic (weakly ferromagnetic and ferroelectric) phase with magnetization [> or =0.5 microB/formula unit (f.u.)] and electric polarization (> or =0.2 microC/cm2) both along the c axis. Exchange striction working between adjacent Fe3+ and Dy3+ layers with the respective layered antiferromagnetic components is proposed as the origin of the ferroelectric polarization in the multiferroic phase.

Polarization reversal in multiferroic TbMnO3 with a rotating magnetic field direction

For the memory application of magnetoelectric multiferroics, not only bistability (i.e., ferroelectricity) but also the switching of the polarization direction with some noneverlasting stimulus is necessary. Here, we report a novel method for the electric polarization reversal in TbMnO3 without the application of an electric field or heat. The direction of the magnetic-field-induced polarization along the a axis (Pa) is memorized even in the zero field where Pa is absent. The polarization direction can be reversed by rotating the magnetic-field direction in the ab plane.

Magnetic field switching between the two orbital-ordered states in DyVO3

The critical phase competition between different spin-orbital-ordered states has been investigated for the DyVO3 single crystal. As temperature is lowered, the compound exhibits a reentrant spin and orbital ordering (SO and OO) transition: C-->G-->C type for SO and G-->C-->G type for OO. It was found that a magnetic field also drives the phase transition from C to G for OO and concomitantly from G to C for SO, the latter of which is coupled with the metamagnetic transition of the Dy 4f moments. The mechanism of this novel magnetic-field-induced orbital switching is discussed.

Optical magnetoelectric effect of patterned oxide superlattices with ferromagnetic interfaces

Nonreciprocal directional dichroism, termed the optical magnetoelectric (OME) effect, has been observed in patterned superlattice (SL) composed of perovskite oxides, LaMnO3, SrMnO3, and LaAlO3. Such a tricolor SL with ferromagnetic interfaces is expected to artificially break both space-inversion and time-reversal symmetries and hence to show the OME effect. The Bragg diffraction from the grating structure with a period of 4 microm fabricated on the SL was employed to sensitively detect the OME effect, yielding the relative change of the diffracted light intensity (~0.2%-0.5%) upon a reversal of either the in-plane magnetization or the propagation vector of the diffracted light.

Direct observation of the bandwidth-disorder induced variation of charge/orbital ordering structure in RE(0.5)(Ca(1-y)Sr(y))(1.5)MnO(4)

Changes in the charge/orbital ordering (CO/OO) structure with the bandwidth of the e(g) band and quenched disorder were investigated in doped manganites RE(0.5)(Ca(1-y)Sr(y))(1.5)MnO(4)(RE = Pr,Eu) with a single-layer perovskite structure. A systematic study of the modulation structure associated with the CO/OO phase demonstrated that the long-range commensurate structure changes to a short-range incommensurate structure with increasing Sr content through the enhancement of the bandwidth and quenched disorder in these systems. At the same time, the transition temperature of CO/OO (T(CO/OO)) decreases. Changes in structure and T(CO/OO) with different A-site combinations reveal that the CO/OO phase is strongly suppressed by the widening of the e(g) band and the stronger quenched disorder in these layered manganites.

Electric control of spin helicity in a magnetic ferroelectric

Magnetic ferroelectrics or multiferroics, which are currently extensively explored, may provide a good arena to realize a novel magnetoelectric function. Here we demonstrate the genuine electric control of the spiral magnetic structure in one such magnetic ferroelectric, TbMnO3. A spin-polarized neutron scattering experiment clearly shows that the spin helicity, clockwise or counterclockwise, is controlled by the direction of spontaneous polarization and hence by the polarity of the small electric field applied on cooling.

Orbital ordering and magnetic field effect in MnV2O4

We studied the structural properties of an orbital-spin-coupled spinel oxide, MnV2O4, mainly by single-crystal x-ray diffraction measurement. It was found that a structural phase transition from cubic to tetragonal and ferrimagnetic ordering occur at the same temperature (Ts,TN=57 K). The structural phase transition was induced also by magnetic field above Ts. In addition, magnetic-field-induced alignment of tetragonal domains results in large magnetostriction below Ts. We also found that the structural phase transition is caused by the antiferro-type ordering of the V t2g orbitals.

Ferroelectric polarization flop in a frustrated magnet MnWO4 induced by a magnetic field

The relationship between magnetic order and ferroelectric properties has been investigated for MnWO4 with a long-wavelength magnetic structure. Spontaneous electric polarization is observed in an elliptical spiral spin phase. The magnetic-field dependence of electric polarization indicates that the noncollinear spin configuration plays a key role for the appearance of the ferroelectric phase. An electric polarization flop from the b direction to the a direction has been observed when a magnetic field above 10 T is applied along the b axis. This result demonstrates that an electric polarization flop can be induced by a magnetic field in a simple system without rare-earth 4f moments.

Aberrant DNA methylation of imprinted loci in superovulated oocytes

BACKGROUND

There is an increased incidence of rare imprinting disorders associated with assisted reproduction technologies (ARTs). The sex-specific epigenetic modifications that are imposed during gametogenesis act as a primary imprint to distinguish maternal and paternal alleles. The most likely candidate for the gametic mark is DNA methylation. However, the timing of DNA methylation acquisition in adult oocytogenesis and the effects of superovulation are unknown.

METHODS

We examined the maternal methylation of PEG1(MEST), LIT1(KCNQ1OT1) and ZAC(PLAGL1) and the paternal methylation of H19 in adult growing oocytes of humans and mice and compared them with the methylation status of mouse neonatal growing oocytes by using bisulphite sequencing. Furthermore, we examined the effects of superovulation in the human and mouse.

RESULTS

Maternal methylation of these genes has already been initiated to some extent in adult human and mouse non-growing oocytes but not in mouse neonates. In addition, the methylation dynamics during adult human and mouse oocyte development changed more gradually than those during neonatal oocyte development. Furthermore, we found the demethylation of PEG1 in growing oocytes from some ART-treated infertile women and a gain in the methylation of H19. We also detected methylation changes in superovulated mice.

CONCLUSION

Our studies in the human and mouse suggest that superovulation can lead to the production of oocytes without their correct primary imprint and highlight the need for more research into ARTs.

In-plane anisotropy of the electronic structure for the charge- and orbital-ordered state in half-doped manganite with layered structure

We report on the in-plane anisotropy of the electronic response in the spin-, charge-, and orbital-ordered phase of a half-doped layered-structure manganite. The optical conductivity spectra for a single domain of Eu1/2Ca3/2MnO4 unambiguously show the anisotropic charge dynamics which well corresponds to the theoretical calculation: the optical conductivity with the polarization along the zigzag ferromagnetic chain direction exhibits a smaller gap and a larger intensity at lower energies than that of the perpendicular polarization mostly due to the charge and orbital ordering and the associated quantum interference effect.

Magnetic reversal of the ferroelectric polarization in a multiferroic spinel oxide

Ferroelectric transition has been detected in a ferrimagnetic spinel oxide of CoCr2O4 upon the transition to the conical spin order below 25 K. The direction [110] of the spontaneous polarization is normal to both the magnetization easy axis [001] and to the propagation axis [110] of the transverse spiral component, in accord with the prediction based on the spin-current model. The reversal of the spontaneous magnetization by a small magnetic field (approximately 0.1 T) induces the reversal of the spontaneous polarization, indicating the clamping of the ferromagnetic and ferroelectric domain walls.

Enhanced optical magnetoelectric effect in a patterned polar ferrimagnet

A simple method to dramatically enhance the optical magnetoelectric (ME) effect, i.e., nonreciprocal directional birefringence, is proposed and demonstrated for a polar ferrimagnet GaFeO3 as a typical example. We patterned a simple grating with a period of 4 microm on a surface of GaFeO3 crystal and used the diffracted light as a probe. The optical ME modulation signal for the Bragg spot of the order n=1 becomes gigantic in the photon energy 1-4 eV and reaches 1-2% of the bare diffracted light intensity in a magnetic field of 500 Oe. This is amplified by more than 3 orders of magnitude compared to that for the reflection of bulk GaFeO3. Fabricating a photonic crystal will make it possible to lead the way for the practical use of the optical ME effect.

Establishment of the primary imprint of the HYMAI/PLAGL1 imprint control region during oogenesis

Imprinting within domains occurs through epigenetic alterations to imprinting centers (ICs) that result in the establishment of parental-specific differences in gene expression. One candidate IC lies within the imprinted domain on human chromosome region 6q24. This domain contains two paternally expressed genes, the zinc finger protein gene PLAGL1 (ZAC/LOT1) and an untranslated mRNAcalled HYMAI. The putative IC overlaps exon 1 of HYMAI and is differentially methylated in somatic tissues. In humans, loss of methylation within this region is seen in some patients with transient neonatal diabetes mellitus, and hypermethylation of this region is found in ovarian cancer and is associated with changes in expression of PLAGL1, suggesting that it plays a key role in regulating gene expression. Differential methylation within this region is conserved in the homologous region on mouse chromosome 10A and is present on the maternal allele. In this paper, we report that DNA methylation is established during the growth phase of oogenesis and that this coincides with the establishment of monoallelic expression from this region lending further support to the hypothesis that this region functions as an IC.

Collinear to spiral spin transformation without changing the modulation wavelength upon ferroelectric transition in Tb1-xDyxMnO3

Lattice modulation and magnetic structures in magnetoelectric compounds Tb1-xDyxMnO3 have been studied around the ferroelectric (FE) Curie temperature TC by x-ray and neutron diffraction. Temperature-independent modulation vectors through TC are observed for the compounds with 0.50 <or=x<or=0.68. This indicates that ferroelectricity with a polarization (P) along the c axis in the RMnO3 series cannot be ascribed to such an incommensurate-commensurate transition of an antiferromagnetic order as was previously anticipated. A neutron diffraction study with x=0.59 shows that the FE transition is accompanied by the transformation of the Mn-spin alignment from sinusoidal (collinear) antiferromagnetism into a transverse-spiral structure. The observed spiral structure below TC is expected to produce P along the c axis with the "inverse" Dzialoshinski-Moriya interaction, which is consistent with observation.

Optical magnetoelectric effect in a submicron patterned magnet

The optical magnetoelectric effect, which is a nonreciprocal directional dichroic response, has been demonstrated in a submicron patterned magnet by monitoring the diffracted visible or near-infrared light intensity. An artificial magnetic superstructure is composed of chevron shaped ">" islands made of the ferromagnetic permalloy Ni(80)Fe(20) with a pitch of 1 microm on silicon substrate, in which both space inversion and time reversal symmetry are broken simultaneously. On the basis of the light-polarization angle and magnetic field H dependence, and also comparing the results with the those of the submicron square patterns, we show that the optical magnetoelectric effect emerges as the finite change (approximately 10(-3) at room temperature in H of 500 Oe) of the diffracted intensity.

Is the posterior belly of the digastric muscle palpable? A qualitative systematic review of the literature

Palpation of the posterior belly of the digastric muscle in the postmandibular region is included in many study protocols and examination schemes of the masticatory system. The aim of the present investigation was to systematically search the dental/medical literature to find evidence for the palpability of this muscle. In August 2004, a systematic search was carried out using different electronic databases (PubMed, Cochrane Library, Web of Science, Japana Centra Revuo Medicina, MedPilot, Latin American and Caribbean Health Sciences, and three on-line databases of dental journals not listed currently in Medline), supplemented by manual search in the Austrian journal Stomatologie. Additional manual searches were carried out in the Journal of Orofacial Pain and Journal of Dental Research to identify pertinent abstracts of scientific congresses. One relevant hit was found in the Japanese database. The manual search showed one pertinent congress abstract. In both publications, the authors concluded that due to anatomical reasons the posterior belly of the digastric muscle was not palpable. Hence, evidence is lacking that the posterior digastric muscle is accessible to palpation. Because the postmandibular region is usually tender upon palpation, a high incidence of positive findings can be expected even among healthy subjects. This may lead to wrong clinical judgments, possibly provoking unnecessary diagnostic and therapeutic measures.

Direct imaging of temperature-dependent layered antiferromagnetism of a magnetic oxide

With the use of a newly developed spin-polarized scanning electron microscope, we have succeeded in obtaining the real-space images of the layered-antiferromagnetic state concurrent with 1-nm-stepped atomic terraces in layered-structure manganite La1.4Sr1.6Mn2O7. The three-dimensional analysis of spin alignment could further reveal the temperature-dependent spin reorientation and the anfiferromagnetic domain walls on the atomic terraces. These ensure the use of the present microscopy for quantitative analysis of local magnetic structures in a broader range of materials, including magnetic oxides and nanomaterials.

Optical magnetoelectric effect in the polar GaFeO3 ferrimagnet

The optical magnetoelectric (ME) effect, i.e., the change of optical absorption upon the reversal of the light propagation direction, has been investigated for a polar ferrimagnet GaFeO3. For dipole- and spin-forbidden d-d transition bands located at 1.2-2.3 eV, a clear signal of the optical ME effect (Deltaalphat approximately 3x10(-3)) is observed with an applied magnetic field as low as 500 Oe and a sample thickness (t) of 50 microm. The observation of a large ME effect in the present compound suggests a possible route to magnification of this novel phenomenon for application.

Commensurate-incommensurate crossover of charge stripe in La2-xSrxNiO4 (x approximately 1/3)

The temperature (T) dependence of the charge-stripe order in La2-xSrxNiO4 has been investigated in the vicinity of x approximately 1/3 by synchrotron radiation x-ray diffraction measurements. With decreasing T, a prominent commensurate-incommensurate (C-IC) crossover is observed in the x<1/3 region, while for the x>1/3 region the IC order is dominant over the whole T range. Such a C-IC crossover is interpreted as the entropy-driven self-doping of the charge stripes, and its x dependence indicates the clear electron-hole asymmetry with the x=1/3 compound as the Mott insulator.

X-ray directional dichroism of a polar ferrimagnet

In a polar ferrimagnet GaFeO3, we have found a novel magneto-optical effect, termed x-ray nonreciprocal directional dichroism (XNDD), that the x-ray absorption at around the K edge of an Fe ion depends on whether the x-ray propagation vector is parallel or antiparallel to the outer product of the magnetization and electric-polarization vectors. The XNDD spectroscopy as demonstrated here can be a useful tool to probe the local magnetism in noncentrosymmetric systems such as magnetic interfaces and nanostructures.

Magnetization-induced second harmonic generation in a polar ferromagnet

Second harmonic generation (SHG) induced by spontaneous magnetization has been investigated for a polar ferromagnetic crystal of GaFeO3. The Kerr rotation of the second harmonic light becomes gigantic with decreasing temperature below the magnetic transition temperature (approximately =205 K), e.g., as large as 73 degrees at 100 K. The magnetic domains can be visualized by using that large nonlinear Kerr rotation. The spectrum of the magnetization-induced SHG as measured indicates the two-photon resonant electronic process on a Fe3+ ion in the crystal.

Magnetic control of ferroelectric polarization

The magnetoelectric effect--the induction of magnetization by means of an electric field and induction of polarization by means of a magnetic field--was first presumed to exist by Pierre Curie, and subsequently attracted a great deal of interest in the 1960s and 1970s (refs 2-4). More recently, related studies on magnetic ferroelectrics have signalled a revival of interest in this phenomenon. From a technological point of view, the mutual control of electric and magnetic properties is an attractive possibility, but the number of candidate materials is limited and the effects are typically too small to be useful in applications. Here we report the discovery of ferroelectricity in a perovskite manganite, TbMnO3, where the effect of spin frustration causes sinusoidal antiferromagnetic ordering. The modulated magnetic structure is accompanied by a magnetoelastically induced lattice modulation, and with the emergence of a spontaneous polarization. In the magnetic ferroelectric TbMnO3, we found gigantic magnetoelectric and magnetocapacitance effects, which can be attributed to switching of the electric polarization induced by magnetic fields. Frustrated spin systems therefore provide a new area to search for magnetoelectric media.

Nonlinear magneto-optical kerr rotation of an oxide superlattice with artificially broken symmetry

Simultaneously broken time-reversal and spatial-inversion symmetries can be realized in the epitaxially grown oxide "tricolor" superlattices composed of three sequential kinds of perovskite layers including a ferromagnetic one (manganese oxide). As a generic feature of such a system, the magnetic-field-induced second-harmonic generation and the resultant Kerr rotation of second-harmonic light were demonstrated. The signal intensity probes the interface magnetization of the superlattice, where temperature variation is shown to be distinct from the bulk feature.

Random potential effect near the bicritical region in perovskite manganites as revealed by comparison with the ordered perovskite analogs

The orbital-charge-spin ordering phase diagram for half-doped perovskites Ln(1/2)Ba(1/2)MnO3 (Ln = rare earth) with ordered Ln/Ba cations has been investigated comparatively with that of the Ln/Ba solid-solution analogs. A large modification of the phase diagram is observed upon the A-site disordering near the original bicritical point between the charge-orbital ordering and ferromagnetic metallic phases. The random potential by quenched disorder inherent in the A-site solid solution is found to suppress the respective long-range orders and gives rise to the colossal magnetoresistive state.

Growth-associated gene expression profiles by microarray analysis of trophoblast of molar pregnancies and normal villi

We used microarray analysis to investigate expression profiles of 589 known genes committed to cell growth control to characterize regulatory circuitry for cell proliferation in complete moles (CMs). CMs are characterized by hyperplastic trophoblast and have a high propensity to give rise to choriocarcinoma. Characteristic alterations in gene expression profiles were observed when compared with normal villi. Fifty-seven genes were significantly up-regulated in CMs and involved the Ras-Map kinase 3, Jak-STAT5, and Wnt signal pathways, implicating growth factor or cytokine-mediated signal pathways in the trophoblastic hyperplasia of CMs. Several genes associated with anti-apoptosis, cell structuring, and/or cell attachment were also up-regulated in CMs. In contrast, relatively fewer genes were down-regulated and these involved IGFBPs, versican, interleukin-1, tumor necrosis factor receptor, CD44, and RAD52. Genes identified in this study may elucidate regulation mechanisms of trophoblastic proliferation and mechanisms causing a pathological phenotype in CMs.

Fine structure of the human cochlear aqueduct: a light and transmission electron microscopic study of decalcified temporal bones

The morphologic features of the human cochlear aqueduct were examined using both light and electron microscopy. The lumen of the cochlear aqueduct was observed to be filled with dense, irregular connective tissue corresponding to dura mater. At the entrance to the cerebrospinal fluid space, the dense connective tissue in the ductal lumen was covered with a thin layer of a few flattened cells, which was contiguous with the arachnoid membrane of the brain. A simple low cuboidal epithelium also separated the perilymphatic space from the lumen of the duct. Our observations confirm the presence of a barrier membrane at the opening to the perilymphatic space, and suggest that no transport occurs in the human cochlear aqueduct.

Ultrastructure of guinea pig stria vascularis processed by rapid freezing and freeze substitution

The rapid-freezing and freeze-substitution method fixes a specimen as if it were prepared before excision. We used this method to study the stria vascularis of guinea pigs using electron microscopy. Findings were essentially the same as those obtained with conventional chemical fixation, although freeze substitution made it possible to observe the membrane structures in a smoother and more linear manner. This method seems to be the procedure of choice for studying the instantaneous movement and behavior of cells.

Charge/orbital ordering structure of Pr(1-x)Ca(x)MnO(3)(x = 3/8) examined by low-temperature transmission electron microscopy

The structural phase transition of Pr(1-x)Ca(x)MnO(3)(x = 3/8) was investigated by means of low-temperature transmission electron microscopy. Superlattice reflection spots with a modulation wave vector q(1) = (0,1/2,0) appeared below 230 K, indicating formation of the d(3x(2-r(2))/d(3y(2)-r(2)) type of charge/orbital ordering. Below 150 K, a new series of superlattice reflection spots with a modulation wave vector q(2) = (1/4,1/4,1/2) appeared, suggesting an additional ordering of excess 1/8 Mn(3+), necessary due to the deviation of x from 1/2, with the occupation of the d(3z(2-r(2)) type of e(g) orbital.

[Collateral blood flow showing dissection-like filling defect on coronary arteriography: a case report]

A 51-year-old man presented under a diagnosis of angina pectoris manifesting as exertional chest pain. First coronary angiography showed severe stenosis with ulceration and spontaneous dissection at the proximal right coronary artery and linear dissection-like filling defects extending to the distal right coronary artery. After about 3 months, repeat coronary angiography showed the previously observed stenosis with unclear dissection, and better developed collaterals from the left coronary artery to the right coronary artery showing the linear dissection-like filling defects. The bilateral coronary angiography did not clearly show filling defects. This phenomenon suggested that the collateral flows were related to filling of the defects. Intravascular ultrasonic imaging demonstrated severe atherosclerotic lesions at the proximal right coronary artery, but no dissection in the distal right coronary artery. Percutaneous transluminal coronary angioplasty for the stenosis was performed successfully with a stent. Coronary angiography after the angioplasty showed no collaterals, and the right ventricular branch appeared, suggesting that the linear dissection-like filling defects extending to the distal right coronary artery were due to the collateral flows. Filling defects extending distal to a severe stenosis must be distinguished carefully from coronary dissection.

Vitamin E inhibits proliferation of primary cultured human mesangial and endothelial cells

BACKGROUND

Vitamin E (VE) has been used as an antioxidant and has been suggested to inhibit the proliferation of mesangial cells in rat and vascular endothelial cells. The direct effect of VE on primary cultures of mesangial cells (MC) and endothelial cells (EC) from the human glomerulus was studied.

METHODS

(1) MC (in 17 or 2.5% FCS DMEM) or EC (in 10 or 5% FCS CSC) at 5,000 cells/well was incubated with serial concentrations of VE from 0.05 to 50 microg/ml (0.06 to 60 IU/l). (2) MC was cocultured with 160, 80, 40 or 20 microg/ml of low-density lipoprotein (LDL) or oxidized LDL (ox-LDL) in 17 or 2.5% FCS DMEM with or without VE. After 3 days of incubation at 37 degrees C in 5% CO(2), cell proliferation was measured by the Premix WST-1 Assay System.

RESULTS

The concentration of VE that significantly inhibited the proliferation of MC cultured in 17 or 2.5% FCS DMEM was 50 or 2.5 microg/ml (60 or 3.0 IU/l), respectively, and that of EC in 10 or 5% FCS medium was 50 or 25 microg/ml (60 or 30 IU/l). VE at 25 microg/ml (30 IU/l) inhibited the LDL proliferative effect on MC cultured in 2.5 FCS DMEM by 21.79-93.21% in a LDL concentration-dependent manner. There was little difference between the effects of LDL and ox-LDL on the VE inhibitory effect on MC under our experimental conditions.

CONCLUSION

VE at low concentrations had no effect on the proliferation of both MC and EC, but at high concentrations, it showed an inhibitory effect on both cells.

Effect of jaw muscle pain and soreness evoked by capsaicin before sleep on orofacial motor activity during sleep

AIMS

Sleep bruxism, which is a form of orofacial motor activity (OMA), and jaw muscle pain and soreness have for a long time been thought to be mutually linked. The aim of this study was to investigate the effect of clinical and experimental jaw muscle pain and soreness on sleep OMA.

METHODS

Twelve healthy subjects aged 21 to 31 years old participated in this study. All of them were aware of signs or symptoms of sleep OMA and were subdivided into a group with clinical pain complaints (n = 5) and a group without pain (n = 7). All subjects slept in the laboratory for 3 consecutive nights, including a habituation night, a baseline night, and an experimental night. Electroencephalographic (EEG) activity and electromyographic (EMG) activity from the masseter muscles were recorded during sleep. On the experimental night, before sleep, all subjects received an injection of capsaicin (0.1 mL, 100 micrograms/mL) into the masseter muscle that had demonstrated the most EMG activity during the previous recordings. The OMA events and episodes were quantified and were compared between the baseline night and the experimental night. Every evening and morning during the study period, pain intensity, unpleasantness, and soreness were scored by the subjects on a visual analog scale (VAS), and pain detection thresholds (PDTs) in the masseter muscles and maximal voluntary occlusal force (MVOF) were also measured.

RESULTS

Pre-sleep injection of capsaicin did not cause significant differences between groups in peak pain intensity on the VAS. The PDT and MVOF did not show any significant differences between groups, injection and non-injection sides, or baseline and experimental nights and mornings. The number of EMG episodes/hour sleep, the number of bursts/hour sleep, and total area of all bursts and episodes during the baseline night were significantly higher in the subjects without pain than in the subjects with pain. However, the capsaicin injection did not cause any significant changes in these parameters.

CONCLUSION

This study suggests that an acute pre-sleep painful stimulus does not have any effect on OMA during sleep, but the study extends previous findings that clinical jaw muscle pain and soreness are associated with less EMG activity in the masticatory muscles.

Prognostic significance of multidrug resistance protein in adult T-cell leukemia

The response of adult T-cell leukemia (ATL) to chemotherapy is poor, and a major obstacle to successful treatment is intrinsic or acquired drug resistance. To determine the clinical significance of multidrug resistance protein (MRP) 1 in ATL, we studied MRP1 expression and its association with clinical outcome. The expression of MRP1 mRNA in leukemia cells from 48 ATL patients was studied by slot blot analysis. The expression level of MRP1 mRNA in chronic-type ATL was significantly higher than that in lymphoma-type ATL (P = 0.033). There was no correlation between MRP1 expression and age, gender, WBC count, LDH, hypercalcemia, blood urea nitrogen, or performance status. However, the expression of MRP1 mRNA correlated only with peripheral blood abnormal lymphocyte counts (P = 0.008). The transporting activity of MRP1 was assessed using membrane vesicles. Membrane vesicles prepared from ATL cells with high expression of MRP1 mRNA showed a higher ATP-dependent leukotriene C(4) uptake than did those with low expression of MRP1 mRNA. This uptake was almost completely inhibited by LTD(4) antagonists ONO-1078 and MK571. In acute- and lymphoma-type ATL, high expression of MRP1 mRNA at diagnosis correlated with shorter survival, and Cox regression analysis revealed that MRP1 expression was an independent prognostic factor. These findings suggest that functionally active MRP1 is expressed in some ATL cells and that it is involved in drug resistance and has a possible causal relationship with poor prognosis in ATL. Multidrug resistance-reversing agents, such as ONO-1078 and MK571, that directly interact and inhibit the transporting activity of MRP1 may be useful for treating ATL patients.