Distinct predictive performance of Rac1 and Cdc42 in cell migration.

We propose a new computation-based approach for elucidating how signaling molecules are decoded in cell migration. In this approach, we performed FRET time-lapse imaging of Rac1 and Cdc42, members of Rho GTPases which are responsible for cell motility, and quantitatively identified the response functions that describe the conversion from the molecular activities to the morphological changes. Based on the identified response functions, we clarified the profiles of how the morphology spatiotemporally changes in response to local and transient activation of Rac1 and Cdc42, and found that Rac1 and Cdc42 activation triggers laterally propagating membrane protrusion. The response functions were also endowed with property of differentiator, which is beneficial for maintaining sensitivity under adaptation to the mean level of input. Using the response function, we could predict the morphological change from molecular activity, and its predictive performance provides a new quantitative measure of how much the Rho GTPases participate in the cell migration. Interestingly, we discovered distinct predictive performance of Rac1 and Cdc42 depending on the migration modes, indicating that Rac1 and Cdc42 contribute to persistent and random migration, respectively. Thus, our proposed predictive approach enabled us to uncover the hidden information processing rules of Rho GTPases in the cell migration

Electrical cardiometry for hemodynamics

Few reports have focused on hemodynamics around delivery in pregnant women because of the difficulty of continuous and noninvasive measurement. Electrical cardiometry allows noninvasive continuous monitoring of hemodynamics and has recently been used in non-pregnant subjects. We compared the use of electrical cardiometry versus transthoracic echocardiography in healthy pregnant women and evaluated hemodynamics immediately after vaginal delivery. In Study 1, electrical cardiometry and transthoracic echocardiography were used to measure cardiac output in 20 pregnant women with threatened premature delivery. A significant correlation was found between the two methods, with electrical cardiometry showing the higher cardiac output. In Study 2, heart rate, stroke volume, and cardiac output were continuously measured in 15 women during vaginal delivery up to 2 h postpartum. Cardiac output increased markedly because of an increased heart rate and stroke volume at the time of newborn delivery. The heart rate then immediately returned to baseline, while cardiac output remained elevated for at least 2 h after delivery because of a sustained high stroke volume. Electrical cardiometry was as readily available as transthoracic echocardiography for evaluating hemodynamics and allowed for continuous measurement during labor. High intrapartum cardiac output was sustained for at least 2 h after vaginal delivery

更新された左室拡張機能評価勧告と心不全入院患者における心血管イベント

Background: Evaluation of diastolic dysfunction is crucial in determining elevated left atrial pressure. However, a validation of the long-term prognostic value of the newly proposed algorithm updated in 2016 has not been performed. The aim of the present study was to investigate the relative value of the updated 2016 diastolic dysfunction grading system for the incidence of readmission in patients with heart failure (HF) with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). Methods: Two hundred thirty-two patients hospitalized with HF were retrospectively evaluated. Subjects were divided into two subgroups: those with HFrEF (n = 127) and those with HFpEF (n = 105). Readmission risk scores were calculated using the Yale Center for Outcomes Research and Evaluation HF, LACE index, and HOSPITAL scores. The primary end point was readmission following HF and cardiac death. Results: Over a period of 24 months, 86 patients were either readmitted or died. Multivariate Cox analysis was performed on both the HFrEF and HFpEF groups. In the HFrEF group, both the 2009 and 2016 algorithms had superior incremental value for the association of the primary end point to several readmission risk scores. In the HFpEF group, only the 2016 algorithm led to significant improvement in association with the primary end point. The 2016 algorithm had incremental value over several readmission risk scores alone. Conclusions: The recommendations of the 2016 algorithm can be useful for readmission and cardiac mortality risk assessment in patients with HFrEF and HFpEF. The use of echocardiography to estimate elevated left atrial pressure appears to identify a higher risk group and may allow a more tailored approach to therapy

Multi-Cellular Logistics of Collective Cell Migration

During development, the formation of biological networks (such as organs and neuronal networks) is controlled by multicellular transportation phenomena based on cell migration. In multi-cellular systems, cellular locomotion is restricted by physical interactions with other cells in a crowded space, similar to passengers pushing others out of their way on a packed train. The motion of individual cells is intrinsically stochastic and may be viewed as a type of random walk. However, this walk takes place in a noisy environment because the cell interacts with its randomly moving neighbors. Despite this randomness and complexity, development is highly orchestrated and precisely regulated, following genetic (and even epigenetic) blueprints. Although individual cell migration has long been studied, the manner in which stochasticity affects multi-cellular transportation within the precisely controlled process of development remains largely unknown. To explore the general principles underlying multicellular migration, we focus on the migration of neural crest cells, which migrate collectively and form streams. We introduce a mechanical model of multi-cellular migration. Simulations based on the model show that the migration mode depends on the relative strengths of the noise from migratory and non-migratory cells. Strong noise from migratory cells and weak noise from surrounding cells causes “collective migration,” whereas strong noise from non-migratory cells causes “dispersive migration.” Moreover, our theoretical analyses reveal that migratory cells attract each other over long distances, even without direct mechanical contacts. This effective interaction depends on the stochasticity of the migratory and non-migratory cells. On the basis of these findings, we propose that stochastic behavior at the single-cell level works effectively and precisely to achieve collective migration in multi-cellular systems

Two New FRET Imaging Measures: Linearly Proportional to and Highly Contrasting the Fraction of Active Molecules.

We developed two new FRET imaging measures for intramolecular FRET biosensors, called linearly proportional (LP) and highly contrasting (HC) measures, which can be easily calculated by the fluorescence intensities of donor and acceptor as a ratio between their weighted sums. As an alternative to the conventional ratiometric measure, which non-linearly depends on the fraction of active molecule, we first developed the LP measure, which is linearly proportional to the fraction of active molecules. The LP measure inherently unmixes bleed-through signals and is robust against fluorescence noise. By extending the LP measure, we furthermore designed the HC measure, which provides highly contrasting images of the molecular activity, more than the ratiometric measure. In addition to their advantages, these measures are insensitive to the biosensor expression level, which is a fundamental property of the ratiometric measure. Using artificial data and FRET imaging data, we showed that the LP measure effectively represents the fraction of active molecules and that the HC measure improves visual interpretability by providing high contrast images of molecular activity. Therefore, the LP and HC measures allow us to gain more quantitative and qualitative insights from FRET imaging than the ratiometric measure

Reconstruction of spatial thermal gradient encoded in thermosensory neuron AFD in Caenorhabditis elegans

During navigation, animals process temporal sequences of sensory inputs to evaluate the surrounding environment. Thermotaxis of Caenorhabditis elegans is a favorable sensory behavior to elucidate how navigating animals process sensory signals from the environment. Sensation and storage of temperature information by a bilaterally symmetric pair of thermosensory neurons, AFD, is essential for the animals to migrate toward the memorized temperature on a thermal gradient. However, the encoding mechanisms of the spatial environment with the temporal AFD activity during navigation remain to be elucidated. Here, we show how the AFD neuron encodes sequences of sensory inputs to perceive spatial thermal environment. We used simultaneous calcium imaging and tracking system for a freely moving animal and characterized the response property of AFD to the thermal stimulus during thermotaxis. We show that AFD neurons respond to shallow temperature increases with intermittent calcium pulses and detect temperature differences with a critical time window of 20 s, which is similar to the timescale of behavioral elements of C. elegans, such as turning. Convolution of a thermal stimulus and the identified response property successfully reconstructs AFD activity. Conversely, deconvolution of the identified response kernel and AFD activity reconstructs the shallow thermal gradient with migration trajectory, indicating that AFD activity and the migration trajectory are sufficient as the encoded signals for thermal environment. Our study demonstrates bidirectional transformation between environmental thermal information and encoded neural activity

Echocardiographic screening for congenital heart disease in 8819 children: A report from local community events for children's healthcare

AbstractBackgroundWe had the opportunity to perform echocardiographic screening of children at local community events for children's healthcare sponsored by the prefectural government. The aim of this study was to assess the utility of echocardiographic screening by measuring the prevalence of congenital heart disease (CHD) and abnormal findings in children without history of diagnosed CHD.MethodsSubjects consisted of 8819 infants and preschool children (1 month to 6 years) who underwent echocardiographic examination at public events from 2001 to 2013. Children with known CHD were excluded.ResultsWe performed echocardiographic screening on 752 (range: 464–993) children at each event. At a total of 12 events, subjects consisted of 3175 infants less than one year (36%), 2292 one-year-olds (26%), 1058 two-year-olds (12%), 794 three-year-olds (9%), and other children up to age six years. We identified echocardiographic abnormalities in 137 children (15.5/1000 subjects), and 89 children (10.1/1000 subjects) were diagnosed with CHD. The prevalence of an echocardiographic abnormality did not change over the 12-year period (Kendall's tau=−0.272, p=0.19).ConclusionsCHD which could not be identified by prenatal echocardiography and neonatal auscultation could be detected in a substantial number of young children by echocardiographic screening. Echocardiographic screening may be useful for early diagnosis of CHD. However, our study is based on cross-sectional data without follow-up. Larger prospective studies are needed to verify the utility of echocardiographic screening with follow-up data in this cohort