Explore the vast range of titles available.

Key Points In the past 10 years, there has been great progress in the development of fluorescent proteins (FPs) to study protein movement and protein interactions. Green FP (GFP)-like proteins have been mutated to be monomers as useful tags for analysing protein movement. FPs have been used to study bulk protein movement, primarily through photobleaching or photoactivation techniques, which allow the determination of protein diffusion and protein binding kinetics. FPs have also been used to track single proteins within the cell. The technique may vary depending on properties of the protein; for example, whether it is soluble. By studying movement, insights have been obtained on protein–protein interactions. Fluorescence cross-correlation spectroscopy (FCCS) has been used to detect the synchronous movement of two proteins fused to different FPs. Bimolecular fluorescence resonance energy transfer (FRET) and bimolecular fluorescence complementation (BiFC) have both been used to study protein proximity, an indicator of protein interactions. In the past 10 years, great progress has been made in the development of fluorescent proteins, including green fluorescent protein (GFP) and GFP-like proteins. Using these proteins together with a range of techniques has furthered our understanding of protein movement and protein–protein interactions. Proteins are always on the move, and this may occur through diffusion or active transport. The realization that the regulation of signal transduction is highly dynamic in space and time has stimulated intense interest in the movement of proteins. Over the past decade, numerous new technologies using fluorescent proteins have been developed, allowing us to observe the spatiotemporal dynamics of proteins in living cells. These technologies have greatly advanced our understanding of protein dynamics, including protein movement and protein interactions.

BackgroundResearch suggests that preventive measures are critical to reducing the spread of coronavirus disease 2019 (COVID-19), but evidence regarding the association between trust in government and the practice of preventive measures is limited.ObjectiveTo examine whether the practice of preventive measures against COVID-19 differs by one’s level of trust in government.DesignA cross-sectional analysis using the Japan COVID-19 and Society Internet Survey (JACSIS) conducted in August and September 2020.ParticipantsA nationally representative sample of Japanese individuals aged 15 through 79 years.Main MeasuresThe primary outcome was the composite score for COVID-19 preventive measures, defined as the percentage of preventive measures an individual reported to be practicing (out of nine measures: social distancing, wearing masks, avoiding closed spaces, avoiding crowded spaces, avoiding close contact settings, hand washing, avoiding touching one’s face, respiratory hygiene, and surface disinfection). The secondary outcomes were (1) support for stay-at-home requests, (2) use of a contact-tracing app, and (3) receipt of the influenza vaccine in the previous season.Key ResultsOur analysis included a total of 25,482 individuals. After adjusting for potential confounders, we found that individuals with high trust in government were likely to practice preventive measures more frequently compared to those with low trust (adjusted composite scores, 83.8% for high- vs. 79.5% for low-trust individuals; adjusted difference, +4.3 percentage points [pp]; 95% CI, +2.4 to +6.2pp; P<0.001). We also found that high trust in government was associated with higher likelihoods of support for stay-at-home requests, use of a contact-tracing app, and receipt of the influenza vaccine in the previous season.ConclusionsHigh trust in government was associated with a higher intensity of practicing COVID-19 preventive measures among Japanese individuals at the national level. Our findings may provide useful information to develop and design effective public health interventions.

Bioluminescence imaging is a tremendous asset to medical research, providing a way to monitor living cells noninvasively within their natural environments. Advances in imaging methods allow researchers to measure tumor growth, visualize developmental processes, and track cell-cell interactions. Yet technical limitations exist, and it is difficult to image deep tissues or detect low cell numbers in vivo. Iwano et al. designed a bioluminescence imaging system that produces brighter emission by up to a factor of 1000 compared with conventional technology (see the Perspective by Nasu and Campbell). Individual tumor cells were successfully visualized in the lungs of mice. Small numbers of striatal neurons were detected in the brains of naturally behaving marmosets. The ability of the substrate to cross the blood-brain barrier should provide important opportunities for neuroscience research. Science , this issue p. 935 ; see also p. 868 A bioengineered light source allows in vivo imaging of individual cells. Bioluminescence is a natural light source based on luciferase catalysis of its substrate luciferin. We performed directed evolution on firefly luciferase using a red-shifted and highly deliverable luciferin analog to establish AkaBLI, an all-engineered bioluminescence in vivo imaging system. AkaBLI produced emissions in vivo that were brighter by a factor of 100 to 1000 than conventional systems, allowing noninvasive visualization of single cells deep inside freely moving animals. Single tumorigenic cells trapped in the mouse lung vasculature could be visualized. In the mouse brain, genetic labeling with neural activity sensors allowed tracking of small clusters of hippocampal neurons activated by novel environments. In a marmoset, we recorded video-rate bioluminescence from neurons in the striatum, a deep brain area, for more than 1 year. AkaBLI is therefore a bioengineered light source to spur unprecedented scientific, medical, and industrial applications.

BackgroundAs the U.S. homeless population grows, so has the challenge of providing effective care to homeless individuals. Understanding hospitals that achieve better outcomes after hospital discharge for homeless patients has important implications for making our health system more sustainable and equitable.ObjectiveTo determine whether homeless patients experience higher rates of readmissions and emergency department (ED) visits after hospital discharge than non-homeless patients, and whether the homeless patients exhibit lower rates of readmissions and ED visits after hospital discharge when they were admitted to hospitals experienced with the treatment of the homeless patients (“homeless-serving” hospitals—defined as hospitals in the top decile of the proportion of homeless patients).DesignA population-based longitudinal study, using the data including all hospital admissions and ED visits in FL, MA, MD, and NY in 2014.ParticipantsParticipants were 3,527,383 patients (median age [IQR]: 63 [49–77] years; 1,876,466 [53%] women; 134,755 [4%] homeless patients) discharged from 474 hospitals.Main MeasuresRisk-adjusted rates of 30-day all-cause readmissions and ED visits after hospital discharge.Key ResultsAfter adjusting for potential confounders, homeless patients had higher rates of readmissions (adjusted rate, 27.3% vs. 17.5%; adjusted odds ratio [aOR], 1.93; 95% CI, 1.69–2.21; p < 0.001) and ED visits after hospital discharge (37.1% vs. 23.6%; aOR, 1.98; 95% CI, 1.74–2.25; p < 0.001) compared with non-homeless patients. Homeless patients treated at homeless-serving hospitals exhibited lower rates of readmissions (23.9% vs. 33.4%; p < 0.001) and ED visits (31.4% vs. 45.4%; p < 0.001) after hospital discharge than homeless patients treated at non-homeless-serving hospitals.ConclusionsHomeless patients were more likely to be readmitted or return to ED within 30 days after hospital discharge, especially when they were treated at hospitals that treat a small proportion of homeless patients. These findings suggest that homeless patients may receive better discharge planning and care coordination when treated at hospitals experienced with caring for homeless people.

The low photostability of fluorescent proteins is a limiting factor in many applications of fluorescence microscopy. Here we present StayGold, a green fluorescent protein (GFP) derived from the jellyfish Cytaeis uchidae . StayGold is over one order of magnitude more photostable than any currently available fluorescent protein and has a cellular brightness similar to mNeonGreen. We used StayGold to image the dynamics of the endoplasmic reticulum (ER) with high spatiotemporal resolution over several minutes using structured illumination microscopy (SIM) and observed substantially less photobleaching than with a GFP variant optimized for stability in the ER. Using StayGold fusions and SIM, we also imaged the dynamics of mitochondrial fusion and fission and mapped the viral spike proteins in fixed cells infected with severe acute respiratory syndrome coronavirus 2. As StayGold is a dimer, we created a tandem dimer version that allowed us to observe the dynamics of microtubules and the excitatory post-synaptic density in neurons. StayGold will substantially reduce the limitations imposed by photobleaching, especially in live cell or volumetric imaging. StayGold is over one order of magnitude more photostable than current fluorescent proteins

There is an emerging interest in brain-mapping projects in countries across the world, including the USA, Europe, Australia and China. In 2014, Japan started a brain-mapping project called Brain Mapping by Integrated Neurotechnologies for Disease Studies (Brain/MINDS). Brain/MINDS aims to map the structure and function of neuronal circuits to ultimately understand the vast complexity of the human brain, and takes advantage of a unique non-human primate animal model, the common marmoset (Callithrix jacchus). In Brain/MINDS, the RIKEN Brain Science Institute acts as a central institute. The objectives of Brain/MINDS can be categorized into the following three major subject areas: (i) structure and functional mapping of a non-human primate brain (the marmoset brain); (ii) development of innovative neurotechnologies for brain mapping; and (iii) human brain mapping; and clinical research. Brain/MINDS researchers are highly motivated to identify the neuronal circuits responsible for the phenotype of neurological and psychiatric disorders, and to understand the development of these devastating disorders through the integration of these three subject areas.

Although StayGold is a bright and highly photostable fluorescent protein, its propensity for obligate dimer formation may hinder applications in molecular fusion and membrane targeting. To attain monovalent as well as bright and photostable labeling, we engineered tandem dimers of StayGold to promote dispersibility. On the basis of the crystal structure of this fluorescent protein, we disrupted the dimerization to generate a monomeric variant that offers improved photostability and brightness compared to StayGold. We applied the new monovalent StayGold tools to live-cell imaging experiments using spinning-disk laser-scanning confocal microscopy or structured illumination microscopy. We achieved cell-wide, high-spatiotemporal resolution and sustained imaging of dynamic subcellular events, including the targeting of endogenous condensin I to mitotic chromosomes, the movement of the Golgi apparatus and its membranous derivatives along microtubule networks, the distribution of cortical filamentous actin and the remolding of cristae membranes within mobile mitochondria. Monomeric and tandem dimer derivatives of the bright and photostable green fluorescent protein StayGold offer versatile tools for tagging target proteins and membranes in extended live-cell imaging.

Hibernating mammals actively lower their body temperature to reduce energy expenditure when facing food scarcity 1 . This ability to induce a hypometabolic state has evoked great interest owing to its potential medical benefits 2 , 3 . Here we show that a hypothalamic neuronal circuit in rodents induces a long-lasting hypothermic and hypometabolic state similar to hibernation. In this state, although body temperature and levels of oxygen consumption are kept very low, the ability to regulate metabolism still remains functional, as in hibernation 4 . There was no obvious damage to tissues and organs or abnormalities in behaviour after recovery from this state. Our findings could enable the development of a method to induce a hibernation-like state, which would have potential applications in non-hibernating mammalian species including humans. In rodents, activation of a population of neurons characterized by the expression of the neuropeptide QRFP induces a hibernation-like state of long-lasting hypothermia and hypometabolism.

Individual cellular activities fluctuate but are constantly coordinated at the population level via cell–cell coupling. A notable example is the somite segmentation clock, in which the expression of clock genes (such as Hes7 ) oscillates in synchrony between the cells that comprise the presomitic mesoderm (PSM) 1 , 2 . This synchronization depends on the Notch signalling pathway; inhibiting this pathway desynchronizes oscillations, leading to somite fusion 3 – 7 . However, how Notch signalling regulates the synchronicity of HES7 oscillations is unknown. Here we establish a live-imaging system using a new fluorescent reporter (Achilles), which we fuse with HES7 to monitor synchronous oscillations in HES7 expression in the mouse PSM at a single-cell resolution. Wild-type cells can rapidly correct for phase fluctuations in HES7 oscillations, whereas the absence of the Notch modulator gene lunatic fringe ( Lfng ) leads to a loss of synchrony between PSM cells. Furthermore, HES7 oscillations are severely dampened in individual cells of Lfng -null PSM. However, when Lfng -null PSM cells were completely dissociated, the amplitude and periodicity of HES7 oscillations were almost normal, which suggests that LFNG is involved mostly in cell–cell coupling. Mixed cultures of control and Lfng -null PSM cells, and an optogenetic Notch signalling reporter assay, revealed that LFNG delays the signal-sending process of intercellular Notch signalling transmission. These results—together with mathematical modelling—raised the possibility that Lfng -null PSM cells shorten the coupling delay, thereby approaching a condition known as the oscillation or amplitude death of coupled oscillators 8 . Indeed, a small compound that lengthens the coupling delay partially rescues the amplitude and synchrony of HES7 oscillations in Lfng -null PSM cells. Our study reveals a delay control mechanism of the oscillatory networks involved in somite segmentation, and indicates that intercellular coupling with the correct delay is essential for synchronized oscillation. Monitoring cells of the mouse presomitic mesoderm using the Achilles reporter fused to HES7 sheds light on the mechanisms that underpin synchronous oscillations in the expression of clock genes between neighbouring cells.

Background: The use of telemedicine outpatient visits has increased dramatically during the COVID-19 pandemic in many countries. Although disparities in access to telemedicine by age and socioeconomic status (SES) have been well-documented, evidence is limited as to how these disparities changed during the COVID-19 pandemic. Moreover, the equity of patient access to telemedicine has been scarcely reported in Japan, despite the huge potential for telemedicine expansion. Objective: We aimed to investigate changes due to age and SES disparities in telemedicine use during the COVID-19 pandemic in Japan. Methods: Using data from a large internet survey conducted between August 25 and September 30, 2020, in Japan, we examined the associations of participant age and SES (educational attainment, urbanicity of residence, and income level) with their telemedicine use in the following two time periods during the pandemic: April 2020 and August-September 2020. Results: Of the 24,526 participants aged 18 to 79 years (50.8% [n=12,446] women), the proportion of individuals who reported using telemedicine increased from 2.0% (n=497) in April 2020 to 4.7% (n=1159) in August-September 2020. After adjusting for potential confounders, younger individuals were more likely to use telemedicine than older individuals in April 2020. Although this pattern persisted in August-September 2020, we also observed a substantial increase in telemedicine use among individuals aged 70 to 79 years (adjusted rates, 0.2% in April 2020 vs 3.8% in August-September 2020; P<.001 after multiple comparisons). We found disparities in telemedicine use by SES in August-September 2020 that did not exist in April 2020. In August-September 2020, individuals with a university degree were more likely to use telemedicine than those with a high school diploma or less (adjusted rates, 6.6% vs 3.5%; P<.001). Individuals living in urban areas exhibited higher rates of telemedicine use than those living in rural areas only in August-September 2020 (adjusted rates, 5.2% vs 3.8%; P<.001). Disparities in telemedicine use by income level were not observed in either time period. Conclusions: In general, younger individuals increased their use of telemedicine compared to older individuals during the pandemic, although individuals in their 70s also increased their use of telemedicine. Disparities in telemedicine use by educational attainment and urbanicity of residence widened during the COVID-19 pandemic.