Prevalence and risk factors of zygotic splitting after 937 848 single embryo transfer cycles.

STUDY QUESTION: What is the prevalence of multiple pregnancy with zygotic splitting after single embryo transfer (SET)? SUMMARY ANSWER: The prevalence of multiple pregnancy with zygotic splitting after SET was 1.36%. WHAT IS KNOWN ALREADY: In 2008, the Japan Society of Obstetrics and Gynaecology (JSOG) recommended the adoption of SET to reduce multiple births. Since then, to improve the clinical pregnancy rate, elective SET using blastocyst transfer and frozen-warmed ET has increased. Blastocyst culture and zona pellucida manipulation, including ICSI and AH, have been widely reported as risk factors for monozygotic twinning. However, all these studies may have included cases with dizygotic pregnancies produced by a transferred embryo and a spontaneous conception. STUDY DESIGN, SIZE, DURATION: A retrospective observational study was performed, based on 937 848 SET cycles in registered ART data from the JSOG between 2007 and 2014. The study was approved by the Registration and Research Subcommittee of the JSOG and Juntendo University Ethics Committee. PARTICIPANTS/MATERIALS, SETTING, METHODS: To identify possible factors affecting the prevalence of zygotic splitting, we identified pregnancies, in which the number of foetuses exceeded the number of gestational sacs (GSs), to restrict our analysis to 'true' zygotic splitting. Multiple logistic regression analysis was performed using singleton pregnancy after SET, as control. P < 0.05 was considered statistically significant. MAIN RESULTS AND THE ROLE OF CHANCE: Fresh and frozen-warmed SET produced 276 934 clinical pregnancies (29.5%/SET), including 4310 twins (1.56% of pregnancies) and 109 triplets (0.04% of pregnancies). Based on sex analysis of dichorionic twins after SET, the prevalence of multiple pregnancy with zygotic splitting was 1.36%. Statistical analysis revealed that compared to singleton pregnancies zygotic splitting pregnancies were associated with frozen-warmed ET cycles (odds ratio [OR] = 1.34; 95% CI: 1.16-1.55), blastocyst culture (OR = 1.79; 95% CI: 1.54-2.09) or AH (OR = 1.21; 95% CI: 1.08-1.35). In fresh ET cycles, the prevalence rate of zygotic splitting pregnancy after single blastocyst transfer was significantly higher than that after SET cycles with cleavage embryos (OR = 2.20; 95% CI: 1.83-2.66). However, no significant difference in ovarian stimulation and fertilization methods was recognized. LIMITATIONS, REASONS FOR CAUTION: In the current Japanese ART registry system, data regarding frozen-warmed ET do not include information about ovarian stimulation and fertilization methods. Registration for AH only began in 2010. There is no way of validating if data submitted by clinics is correct. WIDER IMPLICATIONS OF THE FINDINGS: Clinicians should consider whether to counsel couples about the small increase in the risk of zygotic splitting associated with some embryo manipulations. STUDY FUNDING/COMPETING INTEREST(S): No external funds were used for the study. The authors have no competing interests to declare. TRIAL REGISTRATION NUMBER: None.

Crystallization and vitrification of electrons in a glass-forming charge liquid.

Charge ordering (CO) is a phenomenon in which electrons in solids crystallize into a periodic pattern of charge-rich and charge-poor sites owing to strong electron correlations. This usually results in long-range order. In geometrically frustrated systems, however, a glassy electronic state without long-range CO has been observed. We found that a charge-ordered organic material with an isosceles triangular lattice shows charge dynamics associated with crystallization and vitrification of electrons, which can be understood in the context of an energy landscape arising from the degeneracy of various CO patterns. The dynamics suggest that the same nucleation and growth processes that characterize conventional glass-forming liquids guide the crystallization of electrons. These similarities may provide insight into our understanding of the liquid-glass transition.

Bonding and electronic states of boron in silicon nanowires characterized by an infrared synchrotron radiation beam.

The infrared synchrotron radiation (IR-SR) beamline of SPring-8 as an IR light source was applied to characterize boron (B) atoms in silicon nanowires (SiNWs). The use of an IR-SR beam with much higher brilliance than conventional IR light sources and a wide range of wavenumbers from visible to far IR regions made it possible to detect a local vibrational mode of B in SiNWs. The use of this technique has also made it possible to detect other IR peaks related to transitions of a bound hole from the ground state of a B acceptor atom to excited states, clarifying the electronic state of B acceptors in SiNWs.

Comparing normal walking and compensated walking: their stability and perturbation resistance. A simulation study.

People usually develop different kinds of compensated gait in response to local function deficits, such as muscle weakness, spasticity in specific muscle groups, or joint stiffness, in order to overcome the falling risk factors. Compensated walking has been analysed empirically in the impaired gait analysis area. However, the compensation could be identified spatially and temporally. The stability and perturbation resistance of compensated walking have not been analysed quantitatively. In this research, a biomimetic human walking simulator was employed to model one individual paraplegic subject with plantarflexor spasticity. The pes equinus was expressed by biasing the outputs of plantarflexor neurons corresponding to the spastic muscles. Then, the compensatory mechanism was explored by adjusting the outputs of the other muscles. It was shown that this approach can be used for quantitative analysis of the spastic gait and compensated walking. Thus, this research can improve the understanding of the behaviour of compensated walking, bringing insights not only for building useful walking assist systems with high safety but also for designing effective rehabilitation interventions.

Optical probe of carrier doping by X-ray irradiation in the organic dimer Mott insulator kappa-(BEDT-TTF)_{2}Cu[N(CN)_{2}]Cl.

We investigated the infrared optical spectra of an organic dimer Mott insulator kappa-(BEDT-TTF)_{2}Cu[N(CN)_{2}]Cl, which was irradiated with x rays. We observed that the irradiation caused a large spectral weight transfer from the midinfrared region, where interband transitions in the dimer and Mott-Hubbard bands take place, to a Drude part in a low-energy region; this caused the Mott gap to collapse. The increase of the Drude part indicates a carrier doping into the Mott insulator due to irradiation defects. The strong redistribution of the spectral weight demonstrates that the organic Mott insulator is very close to the phase border of the bandwidth-controlled Mott-insulator-metal transition.

Prevalence of enteric bacteria that inhibit growth of enterohaemorrhagic Escherichia coli O157 in humans.

Enterohaemorrhagic Escherichia coli O157 (O157) is infectious to humans, particularly children, at very low doses and causes not only haemorrhagic colitis but also other serious symptoms. To investigate an association between intestinal bacterial flora and resistance to such infections, we screened faecal samples for the presence of enteric bacteria that are able to suppress the growth of O157. Samples from 303 individuals, 35 children (aged < or =6 years) and 268 adults (aged 20-59 years), were examined. Colonies with different appearances on sorbitol MacConkey agar medium were screened for the production of bacteriocins inhibitory for O157 in an overlay agar plate assay. O157-inhibiting strains were isolated from 52 individuals. The prevalence of these bacteria tended to rise with age, and was significantly higher among 40- to 59-year-old adults (23/101, 22.8%) than among children (3/35, 8.6%; P<0.05). To test the hypothesis that these bacteriocin-producing strains contribute to resistance against O157 in human adults, we examined faecal samples of 25 healthy O157 carriers. Inhibitory bacteria were more prevalent among the latter (9/25, 36.0%) than among age-matched subjects who did not carry O157 (49/268, 18.3%). It appears, therefore, that inhibitory bacteria in the human gut may play a role in inhibiting propagation of O157 and/or suppressing expression of virulence factors by this pathogen.

Comparison of force-time parameters and EMG in static explosive gripping by various exertion conditions: muscle fatigue state and submaximal exertion.

AIM: The purpose of this study was to compare the exertion and electromyography (EMG) properties during the developmental phase (DFmax) in static explosive grip (SEG), rapid submaximal exertion grip, namely fake SEG exertion (FAKE), and SEG in a muscle fatigue state. METHODS: Thirty healthy males and females performed the SEG and FAKE exertions (50% and 75% of peak value as a target value). Then, they performed sustained repeated rhythmic grip for 6 min (30 times x min(-1)), and SEG after 1-min, 4-min, and 7-min (SEG after the exertion). EMG was measured concurrently to compare with the muscle activation property during each grip exertion. Eight force-time parameters evaluating the DFmax in addition to the peak value were selected. RESULTS: The peak value significantly decreased, and the mean power spectrum density shifted to the low-wave in SEG after the exertion as compared with before. Therefore, SEG after the exertion was judged to be a muscle fatigue state. In addition, because the frequency properties in each exertion differed, the muscle activation properties during their DFmaxs were considered to differ. From the comparison between SEG before and after the exertion and FAKE, it is suggested that the time of reaching the peak value and the relative muscle strength when reaching an inflection point are not useful as parameters to evaluate the explosive muscle function during SEG. CONCLUSIONS: The maximal increasing volume during the DFmax and integrated area until 0.25 and 0.5 s could discriminate a difference of the DFmaxs according to each exertion and they are useful parameters.

The characteristics of simple muscle power by gripping: gender differences and reliability of parameters using various loads.

AIM: There are few studies on muscle power during local muscle contractions with a small range of motion such as in gripping. The purposes of this study were to clarify the properties of the developmental phase based on time series of muscle power output, the reliability of the parameters, their relationships and the load intensity derived peak power by gender differences, and to examine the possibility of evaluating muscle power using gripping. METHODS: Fifteen young males and 15 females participated in this study. Based on a crossover experimental design, each subject carried out 2 explosive grips at 20%, 30%, 40% and 50% loads of maximal using a voluntary grip contraction (MVC). The grip contraction velocities, sampled at 100 Hz, were measured accurately using a power instrument with an accelerometer. Muscle power curves were drawn from the product of the velocity and the set-up load. RESULTS: The cross-correlation coefficients between the trials for the average curve of the time-series moving distance, the velocity, and the power in any load were very high (over 0.95) in both genders. The reliability of each parameter was mostly good in both genders (intraclass correlation coefficient, ICC>0.75). The peak power curve differed between genders, and the curve around the peak value in females was irregular. CONCLUSIONS: A gender difference was found in the maximal power and the properties of the power curve. The maximal muscle power appeared at 30-50% MVC in males, and at 20-40% MVC in females. The peak power during the whole contraction, and the time to peak may reflect the conditions throughout the whole of the contraction. The new device used in this study to evaluate local regional muscle power (grip) is a very reliable and useful tool.

Evaluation of preclinical atherosclerosis by flow-mediated dilatation of the brachial artery and carotid artery analysis in patients with a history of Kawasaki disease.

Cardiac sequelae of Kawasaki disease are an important cause of ischemic heart disease in young adults. The possibility of early progression of atherosclerosis following Kawasaki disease is therefore of great concern. We examined whether preclinical atherosclerotic changes are seen in patients with a history of Kawasaki disease, and whether these changes appear in all or in only a proportion of patients. Sixty-five patients with a history of Kawasaki disease, aged 13.1 +/- 2.1 years, and 20 aged-matched controls participated in the study. All subjects underwent flow-mediated dilatation (FMD) of the brachial artery and analysis of carotid artery size and pulse-wave transmission. Patients were classified into four groups depending on the severity of the maximum coronary artery lesion: group 0 (normal), group 1 (mild), group 2 (moderate), and group 3 (severe). There was no statistical difference in the carotid artery analyses between the four groups. FMD (mean +/- SD) was significantly lower in groups 2 and 3 than in groups 0 and 1 and the control group (group 0, 19.4 +/- 3.9%; group 1, 19.5 +/-4.1%; group 2, 8.9 +/- 2.8%; group 3, 4.2 +/- 1.5%; control group, 18.8 +/- 2.8%; p < 0.0001). There was a significantly negative correlation between the severity of the coronary artery lesion and FMD (p < 0.0001 for both). Endothelial dysfunction was revealed by FMD in patients with persistent coronary artery lesions subsequent to Kawasaki disease. Preclinical atherosclerosis may be present only in patients with coronary aneurysms.

A case of Kawasaki disease associated with syndrome of inappropriate secretion of antidiuretic hormone.

UNLABELLED: Kawasaki disease (KD) is an acute vasculitis of unknown aetiology with varied clinical manifestations. Although coronary arteritis is common in the course of KD, central nervous system involvement is rare. We report a case of KD in an infant who developed convulsions and apnoea during his illness associated with syndrome of inappropriate secretion of antidiuretic hormone (SIADH). CONCLUSION: The possibility of severe hyponatraemia should be anticipated in children with KD. Infants with KD are at risk of SIADH and should be monitored closely for its development.

Imaging phase separation near the Mott boundary of the correlated organic superconductors kappa-(BEDT-TTF)2X.

Electronic phase separation consisting of the metallic and insulating domains with 50-100 microm in diameter is found in the organic Mott system kappa-[(h8-BEDT-TTF)(1-x)(d8-BEDT-TTF)x]2Cu[N(CN)2]Br by means of scanning microregion infrared spectroscopy using the synchrotron radiation. The phase separation appears below the critical end temperature 35-40 K of the first-order Mott transition. The observation of the macroscopic size of the domains indicates a different class of the intrinsic electronic inhomogeneity from the nanoscale one reported in the inorganic Mott systems such as high-Tc copper and manganese oxides.

[Report on the ECR2003 (European Congress of Radiology): comparison of apparent diffusion coefficient (ADC) between different MRI scanners].

PURPOSE: To analyze reproducibility of ADC measurements on different MRI scanners. METHODS AND MATERIALS: Diffusion-weighted imaging (DWI) of a home-made phantom (gelatine of different concentration was enclosed in case of circle pillar shape) was performed with the following protocol; spin-echo type echo planar imaging; TR=7000 msec, TE=minimal, matrix=128 x 128, FOV=220 mm, slice thickness=5mm, NEX=1, b-factor=0, 500, and 1000 sec/mm(2) on four different 1.5T MR scanners [GE Signa Horizon (two of them), GE Signa Horizon Lx, and Siemens Magnetom Symphony]. Image analysis were performed on a workstation (GE Medical Systems) or on an operators console of Symphony (for data of Symphony). We used two-point method. Regions of interest (ROIs) were set on every part of ADC map of home-made phantom and ADCs were measured. A linear approximation graphs were also made with every MRI scanner and b-factor. RESULTS: A linear approximation was performed, formulas were y=-0.08x+2.32, r(2)=0.84(Lx), y=-0.09x+2.58, r(2)=0.89(Horizon-1) y=-0.11x+2.67, r(2)=0.95(Horizon-2), y=-0.08x+2.42, r(2)=0.97(Symphony) at b-factor of 500sec/mm(2). y=-0.08x+2.33, r(2)=0.91(Lx), y=-0.09x+2.43, r(2)=0.93(Horizon-1), y=-0.08x +2.48, r(2)=0.92(Horizon-2), y=-0.07x+2.39, r(2)=0.96(Symphony) at b-factor of 1000 sec/mm(2). CONCLUSIONS: ADC values measured at two MRI scanners (same model and older than the other scanners) are higher than other scanners on b-factor=500 sec/mm(2), but at b-factor=1000 sec/mm(2), a good relationship between every scanners was obtained. This result seems to depend on generation of the MRI scanners; newly scanners have good relations b-factor 500 and 1000 sec/mm(2). Pulse sequence design may be improved and optimized in newly scanners. When ADCs were used as quantitative value, a proper b-factor must be used.

Effect of linear polarized near-infrared light irradiation on flexibility of shoulder and ankle joints.

BACKGROUND: There is a possibility that heat stimulus by linear polarized near-infrared light irradiation (PL: Super Lizer HA-30, Tokyo Medical Laboratory) improves the range of joint motion, because the flexibility of soft-part tissues, such as a muscle or a tendon, is improved by increasing the muscle temperature. The purpose of this study was to examine the influence of PL-irradiation on the ranges of shoulder and ankle motions. EXPERIMENTAL DESIGN: 30 healthy young adults (15 males: mean+/-SD, age 19.1+/-0.8 yrs, height 173.3+/-4.6 cm, body mass 68.5+/-8.0 kg and 15 females: mean+/-SD, age 19.2+/-0.7 yrs, height 162.3+/-4.5 cm, body mass 58.1+/-6.6 kg) participated in the experiment under PL-irradiation and no-irradiation (placebo) conditions. MEASURES: the angles of shoulder and ankle joint motions were measured twice, before and after the PL- and placebo-irradiations. The angle of a motion was defined as the angle connecting 3 points at linearity as follows: for the shoulder, the greater trochanter, acromion, and caput ulnare, and for the ankle, the knee joint, fassa of lateral malleolus and metacarpal bone. Each angle was measured when a subject extended or flexed maximally without support. RESULTS: The trial-to-trial reliability of each range of joint motion was very high. All parameters in PL-irradiation were significantly larger in postirradiation than pre-irradiation, and the value of postirradiation in PL-irradiation was significantly greater than that for placebo. The ranges of shoulder and ankle motions in placebo-irradiation were also significantly greater in postirradiation than pre-irradiation. Moreover, the change rate for each range of joint motion between pre- and postirradiations was significantly greater in PL-irradiation in both joints. In PL-irradiation, most subject's motions were greater in postirradiation than pre-irradiation, but not in the placebo-irradiation. The effect of PL-irradiation tended to be greater on subjects with a small range of a joint motion. CONCLUSIONS: It is considered from the present results that the ranges of shoulder and ankle motions became greater with PL-irradiation, and is effective as a warming-up method.

Plasma levels of nitrate in congenital heart disease: comparison with healthy children.

Nitric oxide (NO) is an endothelium- derived relaxing factor, and plasma nitrate is the stable end product of NO production. The aim of this study was to investigate the change in levels of plasma nitrate according to age and to elucidate the effect of pulmonary hypertension (PH) associated with congenital heart disease on NO production. We measured plasma levels of nitrate in 48 healthy children aged 5 days to 12 years to establish the normal range. Forty-six preoperative patients aged 4 months to 12 years with congenital heart disease were studied by cardiac catheterization. Plasma nitrate in healthy children decreased with age, from 1 month to 1 year, and then remained almost constant until the age of 12 years. Plasma nitrate was significantly increased in 22 preoperative patients with PH (mean pulmonary arterial pressure >25 mmHg) compared with age-matched normal controls: (mean 56.9 vs 33.5 micromol/L, p<0.05) and was significantly correlated with pulmonary to systemic pressure ratio (r= 0.83, p < 0.0001). There was no significant difference between plasma nitrate levels in 24 preoperative patients without PH and those in the age-matched normal control (mean 25.6 vs 24.9 micromol/L). In 10 patients with preoperative PH who were examined before and after surgery, plasma nitrate levels remained high in the cases with residual PH but decreased to the normal range in the cases without residual PH. Plasma nitrate level is useful for evaluating PH both before and after operation in patients more than 4 months of age, and it is important to note differences in normal plasma nitrate levels according to age.

Modulation of miniature inhibitory postsynaptic currents by isoflurane in rat dissociated neurons with glycinergic synaptic boutons.

The effects of a volatile anesthetic, isoflurane, on glycinergic miniature inhibitory postsynaptic currents (IPSCs) were investigated in mechanically dissociated rat trigeminal nucleus neurons with intact glycinergic interneuronal presynaptic nerve terminals. The nystatin-perforated patch recording configuration was used to record the miniature IPSCs under voltage-clamp conditions. Isoflurane shifted in a parallel fashion the glycine (Gly) concentration-response curve of enzymatically dissociated neurons to the left without changing the maximum response. Isoflurane reversibly increased the frequency of the miniature IPSCs and prolonged the decay time constant without affecting the mean amplitude. The increase in the frequency of miniature IPSCs in the presence of isoflurane was also observed in Ca(2+)-free external solution. Thapsigargin prohibited the facilitatory effect of isoflurane on the miniature IPSC frequency. It is concluded that isoflurane increases the Ca(2+) concentration in the glycinergic presynaptic nerve terminal by enhancing the release and/or suppressing the uptake of Ca(2+) into stores.

Force developmental phase and reliability in explosive and voluntary grip exertions.

The purposes of this study were to clarify the reliability of two types of grip exertions, explosive grip exertion and voluntary grip exertion up to the maximal grip strength and to examine their force patterns using force-time parameters. Subjects were 100 healthy young male volunteers (age: 17.8+/-2.50 yr.) who had no upper limb injury. Grip strength was measured two times with voluntary grip and then two times with explosive grip. 11 parameters derived from the force-time curve were selected to measure the developmental phase of muscle contraction. The reliability of maximal grip strength in explosive and voluntary grip exertions was very high (intraclass correlation = .95, .93). The difference between two trials in explosive grip tended to be smaller than that for voluntary grip, and reliability of the exertion pattern was higher for explosive grip than voluntary grip. The times to reach 90% of the maximal grip strength and the maximal grip strength in explosive grip were shorter than those in voluntary grip. The other 8 force-time parameters had higher values in explosive grip than voluntary grip and higher reliabilities. The force-time parameters reflect the properties of explosive exertion. The results suggest the possibility that static explosive strength could be evaluated using these force-time parameters.

Mitral valve plasty using artificial chordae in a 1.5-year-old boy with congenital mitral stenosis and absent anterolateral chordae.

A 1.5-year-old boy with refractory heart failure due to congenital mitral stenosis exhibited fusion of the anterolateral leaflets associated with moderate mitral regurgitation due to absent anterolateral chordae. Fused leaflets were incised and the mitral valve opening improved. Mitral regurgitation increased due to the absence of chordae, so 2 pairs of artificial chordae of 5-0 expanded polytetrafluoroethylene suture were anchored to the hypoplastic anterolateral papillary muscle, then attached to the free margin of incised leaflets. Postoperative examination showed improved mitral opening without exacerbated mitral regurgitation.

Plasma nitric oxide products correlate with cardiac index of congenital heart disease.

We wished to determine the relationship between circulating levels of nitric oxide (NO) and cardiac index (CI) in children with congenital heart diseases. We measured the plasma levels of nitrate/nitrite (NO(x)), the stable end products of NO production as well as tumor necrosis factor-alpha (TNF-alpha), atrial natriuretic peptide (ANP), and brain natriuretic peptide in relation to various parameters determined simultaneously. The plasma NO(x) levels correlated negatively with CI (r = -0.541, p < 0.05). No correlation was observed between NO(x) and cardiac output. TNF-alpha correlated with NO(x) levels (r = 0.593, p < 0.005) but not with either CI or cardiac output. Plasma levels of ANP and TNF-alpha were higher in atrial septal defect than those in the control group (p < 0.001 and p < 0.05, respectively). Elevated plasma NO(x) could explain the increased basal release of endothelial NO due to high pulmonary blood flow. Plasma NO(x) correlate negatively with CI in young patients with left-to-right shunt congenital heart diseases.

Effects of isoflurane and hexafluorodiethyl ether on human recombinant GABA(A) receptors expressed in Sf9 cells.

Effects of volatile anesthetics and a volatile convulsant on human recombinant gamma-aminobutyric acid (GABA) type A receptor responses were studied using the whole cell configuration of the patch clamp technique. Sf9 cells were transfected with bacuroviruses carrying cDNAs of alpha1beta2, alpha1beta2gamma2s, alpha3beta2 and alpha3beta2gamma2s subunit combinations of the human GABA(A) receptor. Clinical concentrations of isoflurane (a volatile anesthetic) enhanced the GABA-induced current of the alpha1beta2gamma2s and alpha3beta2gamma2s GABA(A) subunit combinations. On the other hand, isoflurane suppressed the current of the alpha1beta2 and alpha3beta2 subunit combinations, indicating that the anesthetic effects depended upon the presence of gamma2s subunit. A high concentration (2 mM) of isoflurane generated a surge current following the washout of GABA and the anesthetic. Hexafluorodiethyl ether (a volatile convulsant) decreased the GABA-response of the both alpha3beta2gamma2s and alpha3beta2 constructs without generating a surge current. The results suggest that volatile agents affect the receptor-ionophore complex via direct interaction with proteins but not through a perturbation of the membrane lipid environment. A hypothetical sequential model for the anesthetic action is presented.