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ObjectiveThe goal of this study is to provide an ethical framework for clinicians and companies providing noninvasive prenatal testing using cell-free fetal DNA or whole fetal cells.MethodIn collaboration with a National Institutes of Health-supported research ethics consultation committee together with feedback from an interdisciplinary group of clinicians, members of industry, legal experts, and genetic counselors, we developed a set of best practices for the provision of noninvasive prenatal genetic testing.ResultsPrincipal recommendations include the amendment of current informed consent procedures to include attention to the noninvasive nature of new testing and the potential for a broader range of results earlier in the pregnancy. We strongly recommend that tests should only be provided through licensed medical providers and not directly to consumers.ConclusionPrenatal tests, including new methods using cell-free fetal DNA, are not currently regulated by government agencies, and limited professional guidance is available. In the absence of regulation, companies and clinicians should cooperate to adopt responsible best ethical practices in the provision of these tests.

Background The aim of this study was to investigate if there was any serological evidence of Neospora caninum in alpaca populations in south-eastern Australia. Methods and Results Serum samples from 100 alpacas were collected from four farms. All serum samples were screened for N. caninum antibodies using a commercially available competitive ELISA. Of the 100 alpacas sampled, 3 were suspect seropositive for N. caninum. Conclusion There is natural N. caninum seroprevalence in alpacas in south-eastern Australia; however, it remains undetermined whether or not this infection is currently contributing to reproductive failure in alpacas in Australia. [ABSTRACT FROM AUTHOR]

Aging predisposes individuals to reduced bone mass and fragility fractures, which are costly and linked to high mortality. Understanding how aging affects fracture healing is essential for developing therapies to enhance bone regeneration in older adults. During the inflammatory phase of fracture healing, immune cells are recruited to the injury site as periosteal skeletal stem/progenitor cells (pSSPCs) rapidly proliferate and differentiate into osteochondral lineages, allowing for fibrocartilaginous callus formation and complete bone healing. Irrespective of age, how periosteal mesenchymal and immune cells interact during early fracture healing is incompletely understood, limiting our ability to potentially modulate these processes. To address this, we directly analyzed, in parallel, at a single-cell level, isolated murine CD45(+) and CD45(-) periosteal cells dissected from intact and fractured bones, collected three days after injury. Through comprehensive analysis, corroborated by bulk RNA-sequencing, flow cytometry, and histology, we found aging decreases pSSPCs proliferative, marked by a reduced expression of genes required for callus formation and an increased senescence signature. We found that the chemokine Cxcl9 was highly upregulated in aged intact Prrx1+ pSSPCs, predicted to interact with other pSSPCs directly, and associated with increased recruitment of CD8+ T cells at the fracture site three days after injury. Cell-to-cell communication analysis provided insight into the complexity of interactions among the many cell types regulating fracture healing and the impact of aging on these processes. Together, these results provide insight into age-induced alterations in fracture healing, informing the development of improved therapeutic approaches for fragility fractures.

Fracture management largely relies on the bone's inherent healing capabilities and, when necessary, surgical intervention. Currently, there are limited osteoinductive therapies to promote healing, making targeting skeletal stem/progenitor cells (SSPCs) a promising avenue for therapeutic development. A limiting factor for this approach is our incomplete understanding of the molecular mechanisms governing SSPCs' behavior. We have recently identified that the Leucine-rich repeat-containing G-protein coupled receptor 6 (Lgr6) is expressed in sub-populations of SSPCs, and is required for maintaining bone volume during adulthood and for proper fracture healing. Lgr family members (Lgr4-6) are markers of stem cell niches and play a role in tissue regeneration primarily by binding R-Spondin (Rspo1-4). This interaction promotes canonical Wnt (cWnt) signaling by stabilizing Frizzled receptors. Interestingly, our findings here indicate that Lgr6 may also influence cWnt-independent pathways. Remarkably, Lgr6 expression was enhanced during Bmp-mediated osteogenesis of both human and murine cells. Using biochemical approaches, RNA sequencing, and bioinformatic analysis of published single-cell data, we found that elements of BMP signaling, including its target gene, pSMAD, and gene ontology pathways, are downregulated in the absence of Lgr6. Our findings uncover a molecular interdependency between the Bmp pathway and Lgr6, offering new insights into osteogenesis and potential targets for enhancing fracture healing., Competing Interests: Declaration of competing interest The authors declare that the research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024. Published by Elsevier Inc.)

Medium chain fatty acids are commonly consumed as part of diets for endurance sports and as medical treatment in ketogenic diets where these diets regulate energy metabolism and increase adenosine levels. However, the role of the equilibrative nucleoside transporter 1 (ENT1), which is responsible for adenosine transport across membranes in this process, is not well understood. Here, we investigate ENT1 activity in controlling the effects of two dietary medium chain fatty acids (decanoic and octanoic acid), employing the tractable model system Dictyostelium. We show that genetic ablation of three ENT1 orthologues unexpectedly improves cell proliferation specifically following decanoic acid treatment. This effect is not caused by increased adenosine levels triggered by both fatty acids in the presence of ENT1 activity. Instead, we show that decanoic acid increases expression of energy-related genes relevant for fatty acid β-oxidation, and that pharmacological inhibition of ENT1 activity leads to an enhanced effect of decanoic acid to increase expression of tricarboxylicacid cycle and oxidative phosphorylation components. Importantly, similar transcriptional changes have been shown in the rat hippocampus during ketogenic diet treatment. We validated these changes by showing enhanced mitochondria load and reduced lipid droplets. Thus, our data show that ENT1 regulates the medium chain fatty acid-induced increase in cellular adenosine levels and the decanoic acid-induced expression of important metabolic enzymes in energy provision, identifying a key role for ENT1 proteins in metabolic effects of medium chain fatty acids., Competing Interests: Competing interests statement:R.S.B.W. is an executive board member for the International Neurological Ketogenic society. R.S.B.W. has related, partially attributed intellectual property. E.P. was supported through an industry-funded studentship.

Macropinocytosis is a broadly conserved endocytic process discovered nearly 100 years ago, yet still poorly understood. It is prominent in cancer cell feeding, immune surveillance, uptake of RNA vaccines and as an invasion route for pathogens. Macropinocytic cells extend large cups or flaps from their plasma membrane to engulf droplets of medium and trap them in micron-sized vesicles. Here they are digested and the products absorbed. A major problem - discussed here - is to understand how cups are shaped and closed. Recently, lattice light-sheet microscopy has given a detailed description of this process in Dictyostelium amoebae, leading to the 'stalled-wave' model for cup formation and closure. This is based on membrane domains of PIP3 and active Ras and Rac that occupy the inner face of macropinocytic cups and are readily visible with suitable reporters. These domains attract activators of dendritic actin polymerization to their periphery, creating a ring of protrusive F-actin around themselves, thus shaping the walls of the cup. As domains grow, they drive a wave of actin polymerization across the plasma membrane that expands the cup. When domains stall, continued actin polymerization under the membrane, combined with increasing membrane tension in the cup, drives closure at lip or base. Modelling supports the feasibility of this scheme. No specialist coat proteins or contractile activities are required to shape and close cups: rings of actin polymerization formed around PIP3 domains that expand and stall seem sufficient. This scheme may be widely applicable and begs many biochemical questions., (© 2024 The Author(s).)

Brown adipose tissue (BAT) is mammals' primary non-shivering thermogenesis organ, and the molecular mechanisms regulating BAT growth and adipogenesis are largely unknown. The Hippo-YAP pathway has been well-known for controlling organ size, and Vestigial like 4 (VGLL4) is a transcriptional regulator that modulates the Hippo-YAP pathway by competing against YAP for binding to TEAD proteins. In this study, we dissected the function of VGLL4 in regulating BAT development. We generated a conventional Vgll4 mutant mouse line, in which the two Tondu (TDU) domains of VGLL4 were disrupted. We found that deletion of the TDU domains of VGLL4 resulted in perinatal lethality and paucity of the interscapular BAT. Histological and magnetic resonance imaging studies confirmed that the adipogenesis of BAT was impaired in Vgll4 mutants. Adeno-associated virus (AAV) mediated, brown adipocyte-specific overexpression of VGLL4 increased BAT volume and protected the adult male mice from acute cold stress. Genomic studies suggest that VGLL4/TEAD1 complex directly regulates the myogenic and adipogenic gene expression programs of BAT. In conclusion, our data identify VGLL4 as a previously unrecognized adipogenesis factor that regulates classical BAT development.

Objective: To examine the impact of "cross-market" hospital mergers on prices and quality and the extent to which serial acquisitions contribute to any measured effects., Data Sources: 2009-2017 commercial claims from the Health Care Cost Institute (HCCI) and quality measures from Hospital Compare., Study Design: Event study models in which the treated group consisted of hospitals that acquired hospitals further than 50 miles, and the control group was hospitals that were not part of any merger activity (as a target or acquirer) during the study period., Data Extraction Methods: We extracted data for 214 treated hospitals and 955 control hospitals., Principal Findings: Six years after acquisition, cross-market hospital mergers had increased acquirer prices by 12.9% (CI: 0.6%-26.6%) relative to control hospitals, but had no discernible impact on mortality and readmission rates for heart failure, heart attacks and pneumonia. For serial acquirers, the price effect increased to 16.3% (CI: 4.8%-29.1%). For all acquisitions, the price effect was 21.8% (CI: 4.6%-41.7%) when the target's market share was greater than the acquirer's market share versus 9.7% (CI: -0.5% to 20.9%) when the opposite was true. The magnitude of the price effect was similar for out-of-state and in-state cross-market mergers., Conclusions: Additional evidence on the price and quality effects of cross-market mergers is needed at a time when over half of recent hospital mergers have been cross-market. To date, no hospital mergers have been challenged by the Federal Trade Commission on cross-market grounds. Our study is the third to find a positive price effect associated with cross-market mergers and the first to show no quality effect and how serial acquisitions contribute to the price effect. More research is needed to identify the mechanism behind the price effects we observe and analyze price effect heterogeneity., (© 2024 The Authors. Health Services Research published by Wiley Periodicals LLC on behalf of Health Research and Educational Trust.)

Neurons relay information via specialized presynaptic compartments for neurotransmission. Unlike conventional organelles, the specialized apparatus characterizing the neuronal presynapse must form de novo. How the components for presynaptic neurotransmission are transported and assembled is poorly understood. Our results show that the rare late endosomal signaling lipid phosphatidylinositol 3,5-bisphosphate [PI(3,5)P 2 ] directs the axonal cotransport of synaptic vesicle and active zone proteins in precursor vesicles in human neurons. Precursor vesicles are distinct from conventional secretory organelles, endosomes, and degradative lysosomes and are transported by coincident detection of PI(3,5)P 2 and active ARL8 via kinesin KIF1A to the presynaptic compartment. Our findings identify a crucial mechanism that mediates the delivery of synaptic vesicle and active zone proteins to developing synapses.

Phosphoinositide signaling lipids (PIPs) are key regulators of membrane identity and trafficking. Of these, PI(3,5)P2 is one of the least well-understood, despite key roles in many endocytic pathways including phagocytosis and macropinocytosis. PI(3,5)P2 is generated by the phosphoinositide 5-kinase PIKfyve, which is critical for phagosomal digestion and antimicrobial activity. However PI(3,5)P2 dynamics and regulation remain unclear due to lack of reliable reporters. Using the amoeba Dictyostelium discoideum, we identify SnxA as a highly selective PI(3,5)P2-binding protein and characterize its use as a reporter for PI(3,5)P2 in both Dictyostelium and mammalian cells. Using GFP-SnxA, we demonstrate that Dictyostelium phagosomes and macropinosomes accumulate PI(3,5)P2 3 min after engulfment but are then retained differently, indicating pathway-specific regulation. We further find that PIKfyve recruitment and activity are separable and that PIKfyve activation stimulates its own dissociation. SnxA is therefore a new tool for reporting PI(3,5)P2 in live cells that reveals key mechanistic details of the role and regulation of PIKfyve/PI(3,5)P2., (© 2023 Vines et al.)

The widespread consolidation of health systems, hospitals, and physicians has contributed to the high price of healthcare across the United States. While federal antitrust enforcers continue to play an important role in overseeing large mergers, acquisitions, and other consolidating transactions of major healthcare providers, state oversight over healthcare markets is essential to slow consolidation more broadly and address market failures across the country. State laws govern the scope of authority held by state attorneys general and other state agencies to receive notice of, review, and approve, conditionally approve, or block healthcare provider transactions, which can significantly impact the breadth and content of oversight. While blocking potentially anticompetitive transactions can help states maintain any competitive forces that remain in the market, in some situations, approving a transaction with conditions may be the best path forward. Applying conditions to transactions may allow state officials to oversee and govern the behavior of providers post-transaction while states pursue other legislative fixes. Although the use of conditions is a relatively common practice at the state level, little research has been done to explore their use among states. Following a search in all 50 states, this paper examines decisions from state officials imposing conditions intended to address the impacts of transactions on healthcare price, access, and quality and provides recommendations for the effective use of conditions moving forward., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Montague, Davison, Gudiksen and King.)

Background: Fungal-bacterial cocolonization and coinfections pose an emerging challenge among patients suspected of having pulmonary tuberculosis (PTB); however, the underlying pathogenic mechanisms and microbiome interactions are poorly understood. Understanding how environmental microbes, such as fungi and bacteria, coevolve and develop traits to evade host immune responses and resist treatment is critical to controlling opportunistic pulmonary fungal coinfections. In this project, we propose to study the coexistence of fungal and bacterial microbial communities during chronic pulmonary diseases, with a keen interest in underpinning fungal etiological evolution and the predominating interactions that may exist between fungi and bacteria., Objective: This is a protocol for a study aimed at investigating the metabolic and molecular ecological evolution of opportunistic pulmonary fungal coinfections through determining and characterizing the burden, etiological profiles, microbial communities, and interactions established between fungi and bacteria as implicated among patients with presumptive PTB., Methods: This will be a laboratory-based cross-sectional study, with a sample size of 406 participants. From each participant, 2 sputa samples (one on-spot and one early morning) will be collected. These samples will then be analyzed for both fungal and bacterial etiology using conventional metabolic and molecular (intergenic transcribed spacer and 16S ribosomal DNA-based polymerase chain reaction) approaches. We will also attempt to design a genome-scale metabolic model for pulmonary microbial communities to analyze the composition of the entire microbiome (ie, fungi and bacteria) and investigate host-microbial interactions under different patient conditions. This analysis will be based on the interplays of genes (identified by metagenomics) and inferred from amplicon data and metabolites (identified by metabolomics) by analyzing the full data set and using specific computational tools. We will also collect baseline data, including demographic and clinical history, using a patient-reported questionnaire. Altogether, this approach will contribute to a diagnostic-based observational study. The primary outcome will be the overall fungal and bacterial diagnostic profile of the study participants. Other diagnostic factors associated with the etiological profile, such as incidence and prevalence, will also be analyzed using univariate and multivariate schemes. Odds ratios with 95% CIs will be presented with a statistical significance set at P<.05., Results: The study has been approved by the Mbarara University Research Ethic Committee (MUREC1/7-07/09/20) and the Uganda National Council of Science and Technology (HS1233ES). Following careful scrutiny, the protocol was designed to enable patient enrollment, which began in March 2022 at Mbarara University Teaching Hospital. Data collection is ongoing and is expected to be completed by August 2023, and manuscripts will be submitted for publication thereafter., Conclusions: Through this protocol, we will explore the metabolic and molecular ecological evolution of opportunistic pulmonary fungal coinfections among patients with presumptive PTB. Establishing key fungal-bacterial cross-kingdom synergistic relationships is crucial for instituting fungal bacterial coinfecting etiology., Trial Registration: ISRCTN Registry ISRCTN33572982; https://tinyurl.com/caa2nw69., International Registered Report Identifier (irrid): DERR1-10.2196/48014., (©Israel Kiiza Njovu, Pauline Petra Nalumaga, Lucas Ampaire, Edwin Nuwagira, James Mwesigye, Benson Musinguzi, Kennedy Kassaza, Kabanda Taseera, James Kiguli Mukasa, Joel Bazira, Jacob Stanley Iramiot, Andrew Baguma, Felix Bongomin, Richard Kwizera, Beatrice Achan, Michael J Cox, Jason S King, Robin May, Elizabeth R Ballou, Herbert Itabangi. Originally published in JMIR Research Protocols (https://www.researchprotocols.org), 15.08.2023.)

Developmentally programmed polyploidy (whole-genome duplication) of cardiomyocytes is common across evolution. Functions of such polyploidy are essentially unknown. Here, in both Drosophila larvae and human organ donors, we reveal distinct polyploidy levels in cardiac organ chambers. In Drosophila, differential growth and cell cycle signal sensitivity leads the heart chamber to reach a higher ploidy/cell size relative to the aorta chamber. Cardiac ploidy-reduced animals exhibit reduced heart chamber size, stroke volume and cardiac output, and acceleration of circulating hemocytes. These Drosophila phenotypes mimic human cardiomyopathies. Our results identify productive and likely conserved roles for polyploidy in cardiac chambers and suggest that precise ploidy levels sculpt many developing tissues. These findings of productive cardiomyocyte polyploidy impact efforts to block developmental polyploidy to improve heart injury recovery., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)

Macropinocytosis is a conserved endocytic process by which cells engulf droplets of medium into micron-sized vesicles. We use light-sheet microscopy to define an underlying set of principles by which macropinocytic cups are shaped and closed in Dictyostelium amoebae. Cups form around domains of PIP3 stretching almost to their lip and are supported by a specialized F-actin scaffold from lip to base. They are shaped by a ring of actin polymerization created by recruiting Scar/WAVE and Arp2/3 around PIP3 domains, but how cups evolve over time to close and form a vesicle is unknown. Custom 3D analysis shows that PIP3 domains expand from small origins, capturing new membrane into the cup, and crucially, that cups close when domain expansion stalls. We show that cups can close in two ways: either at the lip, by inwardly directed actin polymerization, or the base, by stretching and delamination of the membrane. This provides the basis for a conceptual mechanism whereby closure is brought about by a combination of stalled cup expansion, continued actin polymerization at the lip, and membrane tension. We test this through the use of a biophysical model, which can recapitulate both forms of cup closure and explain how 3D cup structures evolve over time to mediate engulfment., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Remote monitoring rehabilitation programs are new technologies growing in popularity for patients undergoing lower extremity total joint arthroplasty. The purpose of this study was to assess the patients' perceptions of these technologies., Methods: Patients who underwent total hip arthroplasty (THA), total knee arthroplasty arthroplasty (TKA), and unicompartmental knee arthroplasty (UKA) from September 2020 to February 2022, and participated in a clinical study utilizing remote monitoring and an app-based rehabilitation program were given a questionnaire 3 months postoperatively to assess their perceptions of these technologies. There were 166 patients who completed the survey (42 THA; 106 TKA; 18 UKA)., Results: There were 92% of patients who found the technology easy to use. A majority of patients felt the technologies motivated them. The TKA/UKA patients felt more strongly that these technologies allowed the surgeon to monitor their recovery closely (81.9% versus 65.9%; P = .009). There were 85% of THA patients and 94.5% of TKA/UKA patients recommended these technologies. The THA patients felt more strongly that digital rehabilitation could completely replace in-person physical therapy compared to TKA/UKA patients (85.4% versus 41.3%; P < .001). A majority (83%) of patients recommended a combination of inpatient and technology-assisted rehabilitation (THA 90.2%; 84.4% TKA/UKA)., Conclusion: The THA and TKA/UKA patients found remote monitoring rehabilitation easy to use, increased motivation, and recommend it to other patients undergoing lower extremity arthroplasty. They recommend a combination of technology and in-person rehabilitation postoperatively. The THA patients felt these technologies could replace in-person rehabilitation programs., Level of Evidence: IV., (Published by Elsevier Inc.)

Despite the remarkable regenerative capacity of skeletal tissues, nonunion of bone and failure of fractures to heal properly presents a significant clinical concern. Stem and progenitor cells are present in bone and become activated following injury; thus, elucidating mechanisms that promote adult stem cell-mediated healing is important. Wnt-associated adult stem marker Lgr6 is implicated in the regeneration of tissues with well-defined stem cell niches in stem cell-reliant organs. Here, we demonstrate that Lgr6 is dynamically expressed in osteoprogenitors in response to fracture injury. We used an Lgr6-null mouse model and found that Lgr6 expression is necessary for maintaining bone volume and efficient postnatal bone regeneration in adult mice. Skeletal progenitors isolated from Lgr6-null mice have reduced colony-forming potential and reduced osteogenic differentiation capacity due to attenuated cWnt signaling. Lgr6-null mice consist of a lower proportion of self-renewing stem cells. In response to fracture injury, Lgr6-null mice have a deficiency in the proliferation of periosteal progenitors and reduced ALP activity. Further, analysis of the bone regeneration phase and remodeling phase of fracture healing in Lgr6-null mice showed impaired endochondral ossification and decreased mineralization. We propose that in contrast to not being required for successful skeletal development, Lgr6-positive cells have a direct role in endochondral bone repair., Competing Interests: Conflict of interest The authors report no conflict of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The efficient delivery of lysosomes is essential for many cell functions, such as the degradation of unwanted intracellular components by autophagy and the killing and digestion of extracellular microbes within phagosomes. Using the amoeba Dictyostelium discoideum , we find that cells lacking Katnip (Katanin interacting protein) have a general defect in lysosomal delivery and although they make autophagosomes and phagosomes correctly, cells are then unable to digest them. Katnip is largely unstudied yet highly conserved across evolution. Previously studies found that Katnip mutations in animals cause defects in cilia structure. Here we show that Katnip plays a more general role in maintaining microtubule function. We find that loss of Katnip has no overall effect on microtubule dynamics or organization, but is important for the transport and degradation of endocytic cargos. Strikingly, Katnip mutants become highly sensitive to GFP-tubulin expression, which leads to microtubule tangles, defective anaphase extension, and slow cell growth. Our findings establish a general role for Katnip in regulating microtubule function, beyond the roles previously described in cilia. We speculate this is via a key function in microtubule repair, needed to maintain endosomal trafficking and lysosomal degradation.

Climate change exacts a devastating toll on health that is rarely incorporated into the economic calculus of climate action. By aligning health and environmental policy and collaborating across borders, governments and industries can develop powerful initiatives to promote both environmental and human health.

Although hospital consolidation within markets has been well documented, consolidation across markets has not, even though economic theory predicts-and evidence is emerging-that cross-market hospital systems raise prices by exerting market power across markets when negotiating with common customers (primarily insurers). This study analyzes hospital systems using the American Hospital Association Annual Survey Database and defines hospital geographic markets as commuting zones that link workers to places of employment. The share of community hospitals in the US that were part of hospital systems increased from 10 percent in 1970 to 67 percent in 2019, resulting in 3,436 hospitals within 368 systems in 2019. Of these systems, 216 (59 percent) owned hospitals in multiple commuting zones, in part because 55 percent of the 1,500 hospitals targeted for a merger or acquisition between 2010 and 2019 were located in a different commuting zone than the acquirer. Based on market-power differences among hospitals in systems, the number of systems in urban commuting zones that could potentially exert enhanced cross-market power increased from thirty-seven systems in 2009 to fifty-seven systems in 2019, an increase of 54 percent. The increase in cross-market hospital systems warrants concern and scrutiny because of the potential anticompetitive impact of hospital systems exerting market power across markets in negotiations with common customers.

Objective: Fragments of fibrillin-1 and fibrillin-2 will be detectable in the plasma of patients with aortic dissections and aneurysms. We sought to determine whether the plasma fibrillin fragment levels (PFFLs) differ between patients with thoracic aortic pathology and those presenting with nonaortic chest pain., Methods: PFFLs were measured in patients with thoracic aortic aneurysm (n = 27) or dissection (n = 28). For comparison, patients without aortic pathology who had presented to the emergency department with acute chest pain (n = 281) were categorized into three groups according to the cause of the chest pain: ischemic cardiac chest pain; nonischemic cardiac chest pain; and noncardiac chest pain. The PFFLs were measured using a sandwich enzyme-linked immunosorbent assay., Results: Fibrillin-1 fragments were detectable in all patients and were lowest in the ischemic cardiac chest pain group. Age, sex, and the presence of hypertension were associated with differences in fibrillin-1 fragment levels. Fibrillin-2 fragments were detected more often in the thoracic aneurysm and dissection groups than in the emergency department chest pain group ( P  < .0001). Patients with aortic dissection demonstrated a trend toward increased detectability ( P  = .051) and concentrations ( P  = .06) of fibrillin-2 fragments compared with patients with aortic aneurysms. Analysis of specific antibody pairs identified fibrillin-1 B15-HRP26 and fibrillin-2 B205-HRP143 as the most informative in distinguishing between the emergency department and aortic pathology groups., Conclusions: Patients with thoracic aortic dissections demonstrated elevated plasma fibrillin-2 fragment levels (B205-HRP143) compared with patients presenting with ischemic or nonischemic cardiac chest pain and increased fibrillin-1 levels (B15-HRP26) compared with patients with ischemic cardiac chest pain. Investigation of fibrillin-1 and fibrillin-2 fragment generation might lead to diagnostic, therapeutic, and prognostic advances for patients with thoracic aortic dissection.

Carbon (C) allocation and nonstructural carbon (NSC) dynamics play essential roles in plant growth and survival under stress and disturbance. However, quantitative understanding of these processes remains limited. Here we propose a framework where we connect commonly measured carbon cycle components (eddy covariance fluxes of canopy CO 2 exchange, soil CO 2 efflux, and allometry-based biomass and net primary production) by a simple mass balance model to derive ecosystem-level NSC dynamics (NSC i ), C translocation (dC i ), and the biomass production efficiency (BPE i ) in above- and belowground plant (i = agp and bgp) compartments. We applied this framework to two long-term monitored loblolly pine (Pinus taeda) plantations of different ages in North Carolina and characterized the variations of NSC and allocation in years under normal and drought conditions. The results indicated that the young stand did not have net NSC flux at the annual scale, whereas the mature stand stored a near-constant proportion of new assimilates as NSC every year under normal conditions, which was comparable in magnitude to new structural growth. Roots consumed NSC in drought and stored a significant amount of NSC post drought. The above- and belowground dC i and BPE i varied more from year to year in the young stand and approached a relatively stable pattern in the mature stand. The belowground BPE bgp differed the most between the young and mature stands and was most responsive to drought. With the internal C dynamics quantified, this framework may also improve biomass production estimation, which reveals the variations resulting from droughts. Overall, these quantified ecosystem-scale dynamics were consistent with existing evidence from tree-based manipulative experiments and measurements and demonstrated that combining the continuous fluxes as proposed here can provide additional information about plant internal C dynamics. Given that it is based on broadly available flux data, the proposed framework is promising to improve the allocation algorithms in ecosystem C cycle models and offers new insights into observed variability in soil-plant-climate interactions., (© 2022 The Ecological Society of America.)

Policy Points Looking for a way to curtail market power abuses in health care and rein in prices, 20 states have restricted most-favored-nation (MFN) clauses in some health care contracts. Little is known as to whether restrictions on MFN clauses slow health care price growth. Banning MFN clauses between insurers and hospitals in highly concentrated insurer markets seems to improve competition and lead to lower hospital prices., Context: Most-favored-nation (MFN) contract clauses have recently garnered attention from both Congress and state legislatures looking for ways to curtail market power abuses in health care and rein in prices. In health care, a typical MFN contract clause is stipulated by the insurer and requires a health care provider to grant the insurer the lowest (i.e., the most-favored) price among the insurers it contracts with. As of August 2020, 20 states restrict the use of MFN clauses in health care contracts (19 states ban their use in at least some health care contracts), with 8 states prohibiting their use between 2010 and 2016., Methods: Using event study and difference-in-differences research designs, we compared prices for a standardized hospital admission in states that banned MFN clauses between 2010 and 2016 with standardized hospital admission prices in states without MFN bans., Findings: Our results show that bans on MFN clauses reduced hospital price growth in metropolitan statistical areas (MSAs) with highly concentrated insurer markets. Specifically, we found that mean hospital prices in MSAs with highly concentrated insurer markets would have been $472 (2.8%) lower in 2016 had the MSAs been in states that banned MFN clauses in 2010. In 2016, the population in our sample that resided in MSAs with highly concentrated insurer markets was just under 75 million (23% of the US population). Hence, banning MFN clauses in all MSAs in our sample with highly concentrated insurer markets in 2010 would have generated savings on hospital expenditures in the range of $2.4 billion per year., Conclusions: Our empirical findings suggest banning MFN clauses between insurers and providers in highly concentrated insurer markets would improve competition and lead to lower prices and expenditures., (© 2022 Milbank Memorial Fund.)

Opportunistic infections by environmental fungi are a growing clinical problem, driven by an increasing population of people with immunocompromising conditions. Spores of the Mucorales order are ubiquitous in the environment but can also cause acute invasive infections in humans through germination and evasion of the mammalian host immune system. How they achieve this and the evolutionary drivers underlying the acquisition of virulence mechanisms are poorly understood. Here, we show that a clinical isolate of Rhizopus microsporus contains a Ralstonia pickettii bacterial endosymbiont required for virulence in both zebrafish and mice and that this endosymbiosis enables the secretion of factors that potently suppress growth of the soil amoeba Dictyostelium discoideum, as well as their ability to engulf and kill other microbes. As amoebas are natural environmental predators of both bacteria and fungi, we propose that this tri-kingdom interaction contributes to establishing endosymbiosis and the acquisition of anti-phagocyte activity. Importantly, we show that this activity also protects fungal spores from phagocytosis and clearance by human macrophages, and endosymbiont removal renders the fungal spores avirulent in vivo. Together, these findings describe a new role for a bacterial endosymbiont in Rhizopus microsporus pathogenesis in animals and suggest a mechanism of virulence acquisition through environmental interactions with amoebas., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Considering the temporal responses of carbon isotope discrimination (Δ13C) to local water availability in the spatial analysis of Δ13C is essential for evaluating the contribution of environmental and genetic facets of plant Δ13C. Using tree-ring Δ13C from years with contrasting water availability at 76 locations across the natural range of loblolly pine, we decomposed site-level Δ13C signals to maximum Δ13C in well-watered conditions (Δ13Cmax) and isotopic drought sensitivity (m) as a change in Δ13C per unit change of Palmer's Drought Severity Index (PDSI). Site water status, especially the tree lifetime average PDSI, was the primary factor affecting Δ13Cmax. The strong spatial correlation exhibited by m was related to both genetic and environmental factors. The long-term average water availability during the period relevant to trees as indicated by lifetime average PDSI correlated with Δ13Cmax, suggesting acclimation in tree gas-exchange traits, independent of incident water availability. The positive correlation between lifetime average PDSI and m indicated that loblolly pines were more sensitive to drought at mesic than xeric sites. The m was found to relate to a plant's stomatal control and may be employed as a genetic indicator of efficient water use strategies. Partitioning Δ13C to Δ13Cmax and m provided a new angle for understanding sources of variation in plant Δ13C, with several fundamental and applied implications., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Macropinocytosis is a relatively unexplored form of large-scale endocytosis driven by the actin cytoskeleton. Dictyostelium amoebae form macropinosomes from cups extended from the plasma membrane, then digest their contents and absorb the nutrients in the endo-lysosomal system. They use macropinocytosis for feeding, maintaining a high rate of fluid uptake that makes assay and experimentation easy. Mutants collected over the years identify cytoskeletal and signalling proteins required for macropinocytosis. Cups are organized around plasma membrane domains of intense PIP3, Ras and Rac signalling, proper formation of which also depends on the RasGAPs NF1 and RGBARG, PTEN, the PIP3-regulated protein kinases Akt and SGK and their activators PDK1 and TORC2, Rho proteins, plus other components yet to be identified. This PIP3 domain directs dendritic actin polymerization to the extending lip of macropinocytic cups by recruiting a ring of the SCAR/WAVE complex around itself and thus activating the Arp2/3 complex. The dynamics of PIP3 domains are proposed to shape macropinocytic cups from start to finish. The role of the Ras-PI3-kinase module in organizing feeding structures in unicellular organisms most likely predates its adoption into growth factor signalling, suggesting an evolutionary origin for growth factor signalling., (© 2022. The Author(s), under exclusive license to Springer Nature Switzerland AG.)

States can challenge proposed hospital mergers by using antitrust laws to prevent anticompetitive harms. This observational study examined additional state laws-principally charitable trust, nonprofit corporation, health and safety, and certificate-of-need laws-that can serve as complements and substitutes for antitrust laws by empowering states to be notified of, review, and challenge proposed hospital mergers through administrative processes. During the period 2010-19, 862 hospital mergers were proposed, but only forty-two (4.9 percent) were challenged by states, including thirty-five by states without federal involvement, of which twenty-five (71.4 percent) originated in the eight states with the most robust merger review authority. The twenty-five challenges resulted in two mergers being blocked; three being abandoned; and twenty being approved with conditions, including seven with competitive-impact conditions. Hospital market concentration and prices increased at similar rates in these eight states versus other states, potentially because most challenges allowed mergers to proceed with conditions that did not adequately address competitive concerns. Although these findings do not reveal an optimal state framework, elements of advanced state merger review authority may have the potential to improve poorly functioning hospital markets.