re Demographic science aids in understanding the spread and fatality rates of COVID-19 [Social Sciences] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Governments around the world must rapidly mobilize and make difficult policy decisions to mitigate the coronavirus disease 2019 (COVID-19) pandemic. Because deaths have been concentrated at older ages, we highlight the important role of demography, particularly, how the age structure of a population may help explain differences in fatality rates... Full Article
re Asking young children to “do science” instead of “be scientists” increases science engagement in a randomized field experiment [Psychological and Cognitive Sciences] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Subtle features of common language can imply to young children that scientists are a special and distinct kind of person—a way of thinking that can interfere with the development of children’s own engagement with science. We conducted a large field experiment (involving 45 prekindergarten schools, 130 teachers, and over 1,100... Full Article
re Reduced perceptual narrowing in synesthesia [Psychological and Cognitive Sciences] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Synesthesia is a neurologic trait in which specific inducers, such as sounds, automatically elicit additional idiosyncratic percepts, such as color (thus “colored hearing”). One explanation for this trait—and the one tested here—is that synesthesia results from unusually weak pruning of cortical synaptic hyperconnectivity during early perceptual development. We tested the... Full Article
re Intertwined signatures of desiccation and drought tolerance in grasses [Plant Biology] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Grasses are among the most resilient plants, and some can survive prolonged desiccation in semiarid regions with seasonal rainfall. However, the genetic elements that distinguish grasses that are sensitive versus tolerant to extreme drying are largely unknown. Here, we leveraged comparative genomic approaches with the desiccation-tolerant grass Eragrostis nindensis and... Full Article
re Single-cell O2 exchange imaging shows that cytoplasmic diffusion is a dominant barrier to efficient gas transport in red blood cells [Physiology] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Disorders of oxygen transport are commonly attributed to inadequate carrying capacity (anemia) but may also relate to inefficient gas exchange by red blood cells (RBCs), a process that is poorly characterized yet assumed to be rapid. Without direct measurements of gas exchange at the single-cell level, the barriers to O2... Full Article
re Extent of Fermi-surface reconstruction in the high-temperature superconductor HgBa2CuO4+{delta} [Physics] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 High magnetic fields have revealed a surprisingly small Fermi surface in underdoped cuprates, possibly resulting from Fermi-surface reconstruction due to an order parameter that breaks translational symmetry of the crystal lattice. A crucial issue concerns the doping extent of such a state and its relationship to the principal pseudogap and... Full Article
re Detecting electronic coherences by time-domain high-harmonic spectroscopy [Physics] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Ultrafast spectroscopy is capable of monitoring electronic and vibrational states. For electronic states a few eV apart, an X-ray laser source is required. We propose an alternative method based on the time-domain high-order harmonic spectroscopy where a coherent superposition of the electronic states is first prepared by the strong optical... Full Article
re Reversal of hyperactive subthalamic circuits differentially mitigates pain hypersensitivity phenotypes in parkinsonian mice [Neuroscience] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Although pain is a prevalent nonmotor symptom in Parkinson’s disease (PD), it is undertreated, in part because of our limited understanding of the underlying mechanisms. Considering that the basal ganglia are implicated in pain sensation, and that their synaptic outputs are controlled by the subthalamic nucleus (STN), we hypothesized that... Full Article
re Covert sleep-related biological processes are revealed by probabilistic analysis in Drosophila [Neuroscience] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Sleep pressure and sleep depth are key regulators of wake and sleep. Current methods of measuring these parameters in Drosophila melanogaster have low temporal resolution and/or require disrupting sleep. Here we report analysis tools for high-resolution, noninvasive measurement of sleep pressure and depth from movement data. Probability of initiating activity,... Full Article
re Loss of nucleus accumbens low-frequency fluctuations is a signature of chronic pain [Neuroscience] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Chronic pain is a highly prevalent disease with poorly understood pathophysiology. In particular, the brain mechanisms mediating the transition from acute to chronic pain remain largely unknown. Here, we identify a subcortical signature of back pain. Specifically, subacute back pain patients who are at risk for developing chronic pain exhibit... Full Article
re A viral toolkit for recording transcription factor-DNA interactions in live mouse tissues [Neuroscience] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Transcription factors (TFs) enact precise regulation of gene expression through site-specific, genome-wide binding. Common methods for TF-occupancy profiling, such as chromatin immunoprecipitation, are limited by requirement of TF-specific antibodies and provide only end-point snapshots of TF binding. Alternatively, TF-tagging techniques, in which a TF is fused to a DNA-modifying enzyme... Full Article
re Cannabinoid exposure in rat adolescence reprograms the initial behavioral, molecular, and epigenetic response to cocaine [Neuroscience] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 The initial response to an addictive substance can facilitate repeated use: That is, individuals experiencing more positive effects are more likely to use that drug again. Increasing evidence suggests that psychoactive cannabinoid use in adolescence enhances the behavioral effects of cocaine. However, despite the behavioral data, there is no neurobiological... Full Article
re A minor population of macrophage-tropic HIV-1 variants is identified in recrudescing viremia following analytic treatment interruption [Microbiology] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 HIV-1 persists in cellular reservoirs that can reignite viremia if antiretroviral therapy (ART) is interrupted. Therefore, insight into the nature of those reservoirs may be revealed from the composition of recrudescing viremia following treatment cessation. A minor population of macrophage-tropic (M-tropic) viruses was identified in a library of recombinant viruses... Full Article
re Transposon mobilization in the human fungal pathogen Cryptococcus is mutagenic during infection and promotes drug resistance in vitro [Microbiology] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 When transitioning from the environment, pathogenic microorganisms must adapt rapidly to survive in hostile host conditions. This is especially true for environmental fungi that cause opportunistic infections in immunocompromised patients since these microbes are not well adapted human pathogens. Cryptococcus species are yeastlike fungi that cause lethal infections, especially in... Full Article
re Triptolide suppresses IDH1-mutated malignancy via Nrf2-driven glutathione metabolism [Medical Sciences] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Isocitrate dehydrogenase (IDH) mutation is a common genetic abnormality in human malignancies characterized by remarkable metabolic reprogramming. Our present study demonstrated that IDH1-mutated cells showed elevated levels of reactive oxygen species and higher demands on Nrf2-guided glutathione de novo synthesis. Our findings showed that triptolide, a diterpenoid epoxide from Tripterygium... Full Article
re Starvation and antimetabolic therapy promote cytokine release and recruitment of immune cells [Immunology and Inflammation] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Cellular starvation is typically a consequence of tissue injury that disrupts the local blood supply but can also occur where cell populations outgrow the local vasculature, as observed in solid tumors. Cells react to nutrient deprivation by adapting their metabolism, or, if starvation is prolonged, it can result in cell... Full Article
re Landscape analysis of adȷacent gene rearrangements reveals BCL2L14-ETV6 gene fusions in more aggressive triple-negative breast cancer [Genetics] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Triple-negative breast cancer (TNBC) accounts for 10 to 20% of breast cancer, with chemotherapy as its mainstay of treatment due to lack of well-defined targets, and recent genomic sequencing studies have revealed a paucity of TNBC-specific mutations. Recurrent gene fusions comprise a class of viable genetic targets in solid tumors;... Full Article
re Ammonia emission abatement does not fully control reduced forms of nitrogen deposition [Environmental Sciences] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Human activities and population growth have increased the natural burden of reactive nitrogen (N) in the environment. Excessive N deposition on Earth’s surface leads to adverse feedbacks on ecosystems and humans. Similar to that of air pollution, emission control is recognized as an efficient means to control acid deposition. Control... Full Article
re A nonlinear beam model of photomotile structures [Engineering] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Actuation remains a significant challenge in soft robotics. Actuation by light has important advantages: Objects can be actuated from a distance, distinct frequencies can be used to actuate and control distinct modes with minimal interference, and significant power can be transmitted over long distances through corrosion-free, lightweight fiber optic cables.... Full Article
re Reconciling global priorities for conserving biodiversity habitat [Ecology] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Degradation and loss of natural habitat is the major driver of the current global biodiversity crisis. Most habitat conservation efforts to date have targeted small areas of highly threatened habitat, but emerging debate suggests that retaining large intact natural systems may be just as important. We reconcile these perspectives by... Full Article
re Aerosol-photolysis interaction reduces particulate matter during wintertime haze events [Earth, Atmospheric, and Planetary Sciences] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Aerosol–radiation interaction (ARI) plays a significant role in the accumulation of fine particulate matter (PM2.5) by stabilizing the planetary boundary layer and thus deteriorating air quality during haze events. However, modification of photolysis by aerosol scattering or absorbing solar radiation (aerosol–photolysis interaction or API) alters the atmospheric oxidizing capacity, decreases... Full Article
re Metal ions confinement defines the architecture of G-quartet, G-quadruplex fibrils and their assembly into nematic tactoids [Chemistry] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 G-quadruplex, assembled from a square array of guanine (G) molecules, is an important structure with crucial biological roles in vivo but also a versatile template for ordered functional materials. Although the understanding of G-quadruplex structures is the focus of numerous studies, little is known regarding the control of G-quartet stacking... Full Article
re Direct kinetic measurements and theoretical predictions of an isoprene-derived Criegee intermediate [Chemistry] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Isoprene has the highest emission into Earth’s atmosphere of any nonmethane hydrocarbon. Atmospheric processing of alkenes, including isoprene, via ozonolysis leads to the formation of zwitterionic reactive intermediates, known as Criegee intermediates (CIs). Direct studies have revealed that reactions involving simple CIs can significantly impact the tropospheric oxidizing capacity, enhance... Full Article
re Matrix mechanotransduction mediated by thrombospondin-1/integrin/YAP in the vascular remodeling [Cell Biology] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 The extracellular matrix (ECM) initiates mechanical cues that activate intracellular signaling through matrix–cell interactions. In blood vessels, additional mechanical cues derived from the pulsatile blood flow and pressure play a pivotal role in homeostasis and disease development. Currently, the nature of the cues from the ECM and their interaction with... Full Article
re Cryo-EM structure of C9ORF72-SMCR8-WDR41 reveals the role as a GAP for Rab8a and Rab11a [Biochemistry] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 A massive intronic hexanucleotide repeat (GGGGCC) expansion in C9ORF72 is a genetic origin of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Recently, C9ORF72, together with SMCR8 and WDR41, has been shown to regulate autophagy and function as Rab GEF. However, the precise function of C9ORF72 remains unclear. Here, we... Full Article
re Structural basis for Zika envelope domain III recognition by a germline version of a recurrent neutralizing antibody [Biochemistry] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Recent epidemics demonstrate the global threat of Zika virus (ZIKV), a flavivirus transmitted by mosquitoes. Although infection is usually asymptomatic or mild, newborns of infected mothers can display severe symptoms, including neurodevelopmental abnormalities and microcephaly. Given the large-scale spread, symptom severity, and lack of treatment or prophylaxis, a safe and... Full Article
re Regulatory mechanism for the transmembrane receptor that mediates bidirectional vitamin A transport [Biochemistry] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Vitamin A has diverse biological functions and is essential for human survival at every point from embryogenesis to adulthood. Vitamin A and its derivatives have been used to treat human diseases including vision diseases, skin diseases, and cancer. Both insufficient and excessive vitamin A uptake are detrimental, but how its... Full Article
re High-throughput antibody screening from complex matrices using intact protein electrospray mass spectrometry [Biochemistry] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Toward the goal of increasing the throughput of high-resolution mass characterization of intact antibodies, we developed a RapidFire–mass spectrometry (MS) assay using electrospray ionization. We achieved unprecedented screening throughput as fast as 15 s/sample, which is an order of magnitude improvement over conventional liquid chromatography (LC)-MS approaches. The screening enabled... Full Article
re Moderation of mitochondrial respiration mitigates metabolic syndrome of aging [Biochemistry] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Deregulation of mitochondrial dynamics leads to the accumulation of oxidative stress and unhealthy mitochondria; consequently, this accumulation contributes to premature aging and alterations in mitochondria linked to metabolic complications. We postulate that restrained mitochondrial ATP synthesis might alleviate age-associated disorders and extend healthspan in mammals. Herein, we prepared a previously... Full Article
re New HST data and modeling reveal a massive planetesimal collision around Fomalhaut [Astronomy] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 The apparent detection of an exoplanet orbiting Fomalhaut was announced in 2008. However, subsequent observations of Fomalhaut b raised questions about its status: Unlike other exoplanets, it is bright in the optical and nondetected in the infrared, and its orbit appears to cross the debris ring around the star without... Full Article
re Infant behavioral inhibition predicts personality and social outcomes three decades later [Anthropology] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Does infant temperament predict adult personality and life-course patterns? To date, there is scant evidence examining relations between child temperament and adult outcomes, and extant research has relied on limited methods for measuring temperament such as maternal report. This prospective longitudinal study followed a cohort of infants (n = 165)... Full Article
re Molecular and isotopic evidence for milk, meat, and plants in prehistoric eastern African herder food systems [Anthropology] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 The development of pastoralism transformed human diets and societies in grasslands worldwide. The long-term success of cattle herding in Africa has been sustained by dynamic food systems, consumption of a broad range of primary and secondary livestock products, and the evolution of lactase persistence (LP), which allows digestion of lactose... Full Article
re Optimizing Rhizobium-legume symbioses by simultaneous measurement of rhizobial competitiveness and N2 fixation in nodules [Agricultural Sciences] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Legumes tend to be nodulated by competitive rhizobia that do not maximize nitrogen (N2) fixation, resulting in suboptimal yields. Rhizobial nodulation competitiveness and effectiveness at N2 fixation are independent traits, making their measurement extremely time-consuming with low experimental throughput. To transform the experimental assessment of rhizobial competitiveness and effectiveness, we... Full Article
re Loss of the neural-specific BAF subunit ACTL6B relieves repression of early response genes and causes recessive autism [Neuroscience] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Synaptic activity in neurons leads to the rapid activation of genes involved in mammalian behavior. ATP-dependent chromatin remodelers such as the BAF complex contribute to these responses and are generally thought to activate transcription. However, the mechanisms keeping such “early activation” genes silent have been a mystery. In the course... Full Article
re PCARE and WASF3 regulate ciliary F-actin assembly that is required for the initiation of photoreceptor outer segment disk formation [Genetics] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 The outer segments (OS) of rod and cone photoreceptor cells are specialized sensory cilia that contain hundreds of opsin-loaded stacked membrane disks that enable phototransduction. The biogenesis of these disks is initiated at the OS base, but the driving force has been debated. Here, we studied the function of the... Full Article
re Reply to Bowling: How specific emotions are primary in subjective experience [Social Sciences] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Our study in PNAS (1) applies a mathematically based framework to the study of reported emotional experience evoked by music in the United States and China. Germane to theoretical debate, our methods reveal how specific emotions such as “triumph” are more primary across cultures than valence and arousal, a finding... Full Article
re Claims of categorical primacy for musical affect are confounded by using language as a measure [Social Sciences] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Cowen et al. (1) leverage modern gains in data science to describe impressive cross-cultural similarities in the perception of musical affect and do so in unprecedented detail. Their approach is innovative and fundamentally empirical. As such, it should have important applications for prediction in the field of affective computing, which... Full Article
re Reply to Schild et al.: Antisocial personality moderates the causal influence of costly punishment on trust and trustworthiness [Social Sciences] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 A growing literature at the intersection of personality psychology and behavioral economics investigates the interplay between personality and decision making in social dilemmas (1, 2). Engelmann et al. (3) extend prior research in this area by investigating the role of antisocial personality in the context of a trust game with... Full Article
re NRF3-POMP-20S Proteasome Assembly Axis Promotes Cancer Development via Ubiquitin-Independent Proteolysis of p53 and Retinoblastoma Protein [Research Article] By mcb.asm.org Published On :: 2020-04-28T08:00:17-07:00 Proteasomes are essential protease complexes that maintain cellular homeostasis, and aberrant proteasomal activity supports cancer development. The regulatory mechanisms and biological function of the ubiquitin-26S proteasome have been studied extensively, while those of the ubiquitin-independent 20S proteasome system remain obscure. Here, we show that the cap ’n’ collar (CNC) family transcription factor NRF3 specifically enhances 20S proteasome assembly in cancer cells and that 20S proteasomes contribute to colorectal cancer development through ubiquitin-independent proteolysis of the tumor suppressor p53 and retinoblastoma (Rb) proteins. The NRF3 gene is highly expressed in many cancer tissues and cell lines and is important for cancer cell growth. In cancer cells, NRF3 upregulates the assembly of the 20S proteasome by directly inducing the gene expression of the 20S proteasome maturation protein POMP. Interestingly, NRF3 knockdown not only increases p53 and Rb protein levels but also increases p53 activities for tumor suppression, including cell cycle arrest and induction of apoptosis. Furthermore, protein stability and cell viability assays using two distinct proteasome inhibitor anticancer drugs, the 20S proteasome inhibitor bortezomib and the ubiquitin-activating enzyme E1 inhibitor TAK-243, show that the upregulation of the NRF3-POMP axis leads to ubiquitin-independent proteolysis of p53 and Rb and to impaired sensitivity to bortezomib but not TAK-243. More importantly, the NRF3-POMP axis supports tumorigenesis and metastasis, with higher NRF3/POMP expression levels correlating with poor prognoses in patients with colorectal or rectal adenocarcinoma. These results suggest that the NRF3-POMP-20S proteasome assembly axis is significant for cancer development via ubiquitin-independent proteolysis of tumor suppressor proteins. Full Article
re Requirement of the Cep57-Cep63 Interaction for Proper Cep152 Recruitment and Centriole Duplication [Research Article] By mcb.asm.org Published On :: 2020-04-28T08:00:17-07:00 Cep57 has been characterized as a component of a pericentriolar complex containing Cep63 and Cep152. Interestingly, Cep63 and Cep152 self-assemble into a pericentriolar cylindrical architecture, and this event is critical for the orderly recruitment of Plk4, a key regulator of centriole duplication. However, the way in which Cep57 interacts with the Cep63-Cep152 complex and contributes to the structure and function of Cep63-Cep152 self-assembly remains unknown. We demonstrate that Cep57 interacts with Cep63 through N-terminal motifs and associates with Cep152 via Cep63. Three-dimensional structured illumination microscopy (3D-SIM) analyses suggested that the Cep57-Cep63-Cep152 complex is concentrically arranged around a centriole in a Cep57-in and Cep152-out manner. Cep57 mutant cells defective in Cep63 binding exhibited improper Cep63 and Cep152 localization and impaired Sas6 recruitment for procentriole assembly, proving the significance of the Cep57-Cep63 interaction. Intriguingly, Cep63 fused to a microtubule (MT)-binding domain of Cep57 functioned in concert with Cep152 to assemble around stabilized MTs in vitro. Thus, Cep57 plays a key role in architecting the Cep63-Cep152 assembly around centriolar MTs and promoting centriole biogenesis. This study may offer a platform to investigate how the organization and function of the pericentriolar architecture are altered by disease-associated mutations found in the Cep57-Cep63-Cep152 complex. Full Article
re E2F6-Mediated Downregulation of MIR22HG Facilitates the Progression of Laryngocarcinoma by Targeting the miR-5000-3p/FBXW7 Axis [Research Article] By mcb.asm.org Published On :: 2020-04-28T08:00:17-07:00 Recently, abundant evidence has clarified that long noncoding RNAs (lncRNAs) play an oncogenic or anticancer role in the tumorigenesis and development of diverse human cancers. Described as a crucial regulator in some cancers, MIR22HG has not yet been studied in laryngocarcinoma and therefore the underlying regulatory role of MIR22HG in laryngocarcinoma is worth detecting. In this study, MIR22HG expression in laryngocarcinoma cells was confirmed to be downregulated, and upregulated MIR22HG expression led to suppressive effects on laryngocarcinoma cell proliferation and migration. Molecular mechanism assays revealed that MIR22HG sponges miR-5000-3p in laryngocarcinoma cells. Besides, decreased expression of miR-5000-3p suppressed laryngocarcinoma cell proliferation and migration. Moreover, the FBXW7 gene was reported to be a downstream target gene of miR-5000-3p in laryngocarcinoma cells. More importantly, rescue assays verified that FBXW7 depletion or miR-5000-3p upregulation countervailed the repressive effects of MIR22HG overexpression on laryngocarcinoma progression. In addition, E2F6 was proved to be capable of inhibiting MIR22HG transcription in laryngocarcinoma cells. To sum up, E2F6-induced downregulation of MIR22HG promotes laryngocarcinoma progression through the miR-5000-3p/FBXW7 axis. Full Article
re AKT Regulates Mitotic Progression of Mammalian Cells by Phosphorylating MASTL, Leading to Protein Phosphatase 2A Inactivation [Research Article] By mcb.asm.org Published On :: 2020-04-28T08:00:17-07:00 Microtubule-associated serine/threonine kinase like (MASTL), also known as Greatwall (Gwl) kinase, has an important role in the regulation of mitosis. By inhibiting protein phosphatase 2A (PP2A), it plays a crucial role in activating one of the most important mitotic kinases, known as cyclin-dependent kinase 1 (CDK1). MASTL has been seen to be upregulated in various types of cancers and is also involved in tumor recurrence. It is activated by CDK1 through phosphorylations in the activation/T-loop, but the complete mechanism of its activation is still unclear. Here, we report that AKT phosphorylates MASTL at residue T299, which plays a critical role in its activation. Our results suggest that AKT increases CDK1-mediated phosphorylation and hence the activity of MASTL, which, in turn, promotes mitotic progression through PP2A inhibition. We also show that the oncogenic potential of AKT is augmented by MASTL activation, since AKT-mediated proliferation in colorectal cell lines can be attenuated by inhibiting and/or silencing MASTL. In brief, we report that AKT plays an important role in the progression of mitosis in mammalian cells and that it does so through the phosphorylation and activation of MASTL. Full Article
re Articles of Significant Interest in This Issue [Spotlight] By mcb.asm.org Published On :: 2020-04-28T08:00:17-07:00 Full Article
re Determining the Bioenergetic Capacity for Fatty Acid Oxidation in the Mammalian Nervous System [Research Article] By mcb.asm.org Published On :: 2020-04-28T08:00:17-07:00 The metabolic state of the brain can greatly impact neurologic function. Evidence of this includes the therapeutic benefit of a ketogenic diet in neurologic diseases, including epilepsy. However, brain lipid bioenergetics remain largely uncharacterized. The existence, capacity, and relevance of mitochondrial fatty acid β-oxidation (FAO) in the brain are highly controversial, with few genetic tools available to evaluate the question. We have provided evidence for the capacity of brain FAO using a pan-brain-specific conditional knockout (KO) mouse incapable of FAO due to the loss of carnitine palmitoyltransferase 2, the product of an obligate gene for FAO (CPT2B–/–). Loss of central nervous system (CNS) FAO did not result in gross neuroanatomical changes or systemic differences in metabolism. Loss of CPT2 in the brain did not result in robustly impaired behavior. We demonstrate by unbiased and targeted metabolomics that the mammalian brain oxidizes a substantial quantity of long-chain fatty acids in vitro and in vivo. Loss of CNS FAO results in robust accumulation of long-chain acylcarnitines in the brain, suggesting that the mammalian brain mobilizes fatty acids for their oxidation, irrespective of diet or metabolic state. Together, these data demonstrate that the mammalian brain oxidizes fatty acids under normal circumstances with little influence from or on peripheral tissues. Full Article
re Correction for Dietz et al., "2019 Novel Coronavirus (COVID-19) Pandemic: Built Environment Considerations To Reduce Transmission" By msystems.asm.org Published On :: 2020-05-05T07:30:12-07:00 Full Article
re Isolation and Characterization of the Novel Phage JD032 and Global Transcriptomic Response during JD032 Infection of Clostridioides difficile Ribotype 078 By msystems.asm.org Published On :: 2020-05-05T07:30:12-07:00 ABSTRACT Insights into the interaction between phages and their bacterial hosts are crucial for the development of phage therapy. However, only one study has investigated global gene expression of Clostridioides (formerly Clostridium) difficile carrying prophage, and transcriptional reprogramming during lytic infection has not been studied. Here, we presented the isolation, propagation, and characterization of a newly discovered 35,109-bp phage, JD032, and investigated the global transcriptomes of both JD032 and C. difficile ribotype 078 (RT078) strain TW11 during JD032 infection. Transcriptome sequencing (RNA-seq) revealed the progressive replacement of bacterial host mRNA with phage transcripts. The expressed genes of JD032 were clustered into early, middle, and late temporal categories that were functionally similar. Specifically, a gene (JD032_orf016) involved in the lysis-lysogeny decision was identified as an early expression gene. Only 17.7% (668/3,781) of the host genes were differentially expressed, and more genes were downregulated than upregulated. The expression of genes involved in host macromolecular synthesis (DNA/RNA/proteins) was altered by JD032 at the level of transcription. In particular, the expression of the ropA operon was downregulated. Most noteworthy is that the gene expression of some antiphage systems, including CRISPR-Cas, restriction-modification, and toxin-antitoxin systems, was suppressed by JD032 during infection. In addition, bacterial sporulation, adhesion, and virulence factor genes were significantly downregulated. This study provides the first description of the interaction between anaerobic spore-forming bacteria and phages during lytic infection and highlights new aspects of C. difficile phage-host interactions. IMPORTANCE C. difficile is one of the most clinically significant intestinal pathogens. Although phages have been shown to effectively control C. difficile infection, the host responses to phage predation have not been fully studied. In this study, we reported the isolation and characterization of a new phage, JD032, and analyzed the global transcriptomic changes in the hypervirulent RT078 C. difficile strain, TW11, during phage JD032 infection. We found that bacterial host mRNA was progressively replaced with phage transcripts, three temporal categories of JD032 gene expression, the extensive interplay between phage-bacterium, antiphage-like responses of the host and phage evasion, and decreased expression of sporulation- and virulence-related genes of the host after phage infection. These findings confirmed the complexity of interactions between C. difficile and phages and suggest that phages undergoing a lytic cycle may also cause different phenotypes in hosts, similar to prophages, which may inspire phage therapy for the control of C. difficile. Full Article
re Re: Primary Care Practices Implementation of Patient-Team Partnership: Findings from EvidenceNOW Southwest By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Full Article
re Re: Abnormally Low Hemoglobin A1c as Harbinger of Hemoglobinopathy By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Full Article
re Crashing Out of a Career By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 This article is meant as a personal reflection on my unexpected retirement, and includes memories and thoughts about my career with the Indian Health Service near the border with Mexico, serving the Tohono O’odham tribe. Full Article
re Prognostic Indices for Advance Care Planning in Primary Care: A Scoping Review By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Background: Patient identification is an important step for advance care planning (ACP) discussions. Objectives: We conducted a scoping review to identify prognostic indices potentially useful for initiating ACP. Methods: We included studies that developed and/or validated a multivariable prognostic index for all-cause mortality between 6 months and 5 years in community-dwelling adults. PubMed was searched in October 2018 for articles meeting our search criteria. If a systematic review was identified from the search, we checked for additional eligible articles in its references. We abstracted data on population studied, discrimination, calibration, where to find the index, and variables included. Each index was further assessed for clinical usability. Results: We identified 18 articles with a total of 17 unique prognostic indices after screening 9154 titles. The majority of indices (88%) had c-statistics greater than or equal to 0.70. Only 1 index was externally validated. Ten indices, 8 developed in the United States and 2 in the United Kingdom, were considered clinically usable. Conclusion: Of the 17 unique prognostic indices, 10 may be useful for implementation in the primary care setting to identify patients who may benefit from ACP discussions. An index classified as "clinically usable" may not be easy to use because of a large number of variables that are not routinely collected and the need to program the index into the electronic medical record. Full Article