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A cesarean section (C-section) is common practice in complicated deliveries that otherwise carry risk of severe complications. However, C-sections themselves carry risks, as do all major surgical procedures. In this paper, I examine the causal effects of C-sections on child and maternal outcomes in a population of high-risk deliveries, namely breech births. To capture the causal effect of C-sections, I exploit an information shock to the medical community on the effectiveness of the procedure. Using Swedish administrative data, I find that C-sections improve the health of children at birth and during childhood. I find no significant impacts on maternal morbidity or labor market outcomes.

Objectives Frontline workers have been a bulwark in the fight against COVID-19, while being subject to major unexpected stressors. These include conflicting news, evolving guidelines, perceived inadequate personal protective equipment, overflow of patients with rising death counts, absence of disaster training, and limitations in the implementation of social distancing. This study investigates the incidence and associated factors of depression, suicidal thoughts, and burnout among physicians during the COVID-19 pandemic. Methods In a cross-sectional survey-based study of resident, fellow, and attending physicians from a tertiary university hospital during the height of the COVID-19 pandemic in New York from April 24 to May 15, 2020, demographics and practice specialty, attending vs. resident/fellow status, call frequency, emotional exhaustion, depersonalization, and depression severity were examined. Results Two hundred twenty-five subjects completed the survey (response rate of 16.3%), with rates of 6.2% depression, 6.6% suicidal ideation, and 19.6% burnout. Depression, suicidal ideation, and burnout were all associated with history of prior depression/anxiety and frequency of on call. Suicidal ideation and burnout were also associated with younger age. There was no difference in rates of depression, suicidal ideation, or burnout between attending and resident physicians. Female physicians reported less work-life balance and more burnout. Conclusions These findings highlight the importance of considering physician mental health during times of peak stress, such as natural or man-made disasters. The prominence of premorbid depression/anxiety as a relevant factor underscores the need to further understand physician mental health and provide early screening and treatment.

Introduction: This study compares rates of depression, suicidal ideation, and burnout among resident/fellow and attending physicians in orthopaedic surgery to other specialties during height/end of the first wave of the coronavirus disease 2019 (COVID-19) pandemic at our institution. Main outcomes and measures included suicidal ideation, Patient Health Questionnaire for Depression (PHQ-9) scores for depression, and 2 single-item measures for emotional exhaustion and depersonalization. This study provides valuable information regarding orthopaedic surgeon mental health during world crises. Methods: This is a cross-sectional survey-based study of resident, fellow, and attending physicians from 26 specialties during and after the first wave of the COVID-19 pandemic at our institution from April 24, 2020 to May 15, 2020. The survey contained 22 items. This includes consent, demographics and general data, 2 single-item questions of emotional exhaustion and depersonalization, and the PHQ-9. Subjects were eligible if they were a resident/fellow or attending physician at our institution. Results: The response rate for the study was 16.31%. Across all specialties rates were 6.2% depression, 19.6% burnout, and 6.6% suicidal ideation. The results for orthopaedic surgeons are as follows: 0% tentative diagnosis of depression, 3.8% suicidal ideation, and 4% burnout. Anesthesiology had the highest rate of depression (14.3%). Internal medicine and other non-surgical specialties had the highest rate of suicidal ideation (10.2%). Orthopaedic surgeons were significantly more likely to achieve work–life balance and experience less burnout than anesthesiologists and pediatricians. Discussion: Depression, suicidal ideation, and burnout continue to affect physicians across all specialties. These issues are amplified in light of crisis. Job satisfaction and rigorous training may be protective factors that allow orthopaedic surgeons to adapt to novel clinical settings under stress when compared to anesthesiologists and pediatricians. Resilience training and stress management strategies should continue to be investigated to better prepare physicians for world crises.

Significance We analyzed data from saliva-based COVID-19 screening deployed on the University of Colorado Boulder campus. Our dataset is unique in that all SARS-CoV-2−positive individuals reported no symptoms at the time of saliva collection, and therefore were infected but asymptomatic or presymptomatic. We found that 1) the distribution of viral loads observed in our asymptomatic college population was indistinguishable from what has been reported in hospitalized populations; 2) regardless of symptomatic status, approximately 50% of individuals who test positive for SARS-CoV-2 seem to be in noninfectious phases of the infection; and 3) just 2% of infected individuals carry 90% of the virions circulating within communities, serving as viral “supercarriers” and likely also superspreaders., We analyze data from the fall 2020 pandemic response efforts at the University of Colorado Boulder, where more than 72,500 saliva samples were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using qRT-PCR. All samples were collected from individuals who reported no symptoms associated with COVID-19 on the day of collection. From these, 1,405 positive cases were identified. The distribution of viral loads within these asymptomatic individuals was indistinguishable from what has been previously observed in symptomatic individuals. Regardless of symptomatic status, ∼50% of individuals who test positive for SARS-CoV-2 seem to be in noninfectious phases of the disease, based on having low viral loads in a range from which live virus has rarely been isolated. We find that, at any given time, just 2% of individuals carry 90% of the virions circulating within communities, serving as viral “supercarriers” and possibly also superspreaders.

Supplemental Material, sj-pdf-1-gos-10.1177_21514593211035230 for Orthopaedic Surgeon Mental Health During the COVID-19 Pandemic by Samer M. Al-Humadi, Ricardo Cáceda, Brian Bronson, Megan Paulus, Houlin Hong and Samantha Muhlrad in Geriatric Orthopaedic Surgery & Rehabilitation

Here, we develop a simple molecular test for SARS-CoV-2 in saliva based on reverse transcription loop-mediated isothermal amplification (RT-LAMP). The test has two steps: 1) heat saliva with a stabilization solution, and 2) detect virus by incubating with a primer/enzyme mix. After incubation, saliva samples containing the SARS-CoV-2 genome turn bright yellow. Because this test is pH dependent, it can react falsely to some naturally acidic saliva samples. We report unique saliva stabilization protocols that rendered 295 healthy saliva samples compatible with the test, producing zero false positives. We also evaluated the test on 278 saliva samples from individuals who were infected with SARS-CoV-2 but had no symptoms at the time of saliva collection, and from 54 matched pairs of saliva and anterior nasal samples from infected individuals. The Saliva TwoStep test described herein identified infections with 94% sensitivity and >99% specificity in individuals with sub-clinical (asymptomatic or pre-symptomatic) infections.

P bodies are archetypal biomolecular condensates that concentrate proteins and RNA without a surrounding membrane. While dozens of P body proteins are known, the concentrations of components in the compartment have not been measured. We used live cell imaging to generate a quantitative inventory of the major proteins in yeast P bodies. Only 7 proteins are highly concentrated in P bodies (5.1-15 μM); the 24 others examined are appreciably lower (most ≤ 2.4 μM). P body concentration correlates inversely with cytoplasmic exchange rate. Sequence elements driving Dcp2 concentration into P bodies are distributed across the protein and act cooperatively. Strong correlation between interaction valency of components and P body concentration suggests how the composition of other condensates may be estimated from known interaction data. Our data indicate that P bodies, and probably other condensates, are biochemically simpler than suggested by proteomic analyses, with implications for specificity, reconstitution and evolution.

Histones are located in the cell nucleus. They are positively charged small proteins which became extracellular upon apoptosis, necrosis, and infection – induced cell death. The mixture of extracellular Histones was shown to bundle Actin filaments and digested by bacterial proteases, which was inhibited by DNA and Actin. Here we studied the interaction of five major family of Histones, H2A, H2B, H3.1, H1 and H4, with DNA and Actin filaments. We found that all the Histones studied bound to DNA, increased the viscosity of Actin containing solutions and bundled Actin filaments in various degrees. The bundling of Actin filaments by Histones was inhibited by DNA, NaCl and DNase1. DNA and Actin filaments also inhibited the proteolysis of the five Histones by Subtilisin, Fusolisin and Pseudomonas Aeruginosa bacterial proteases. Both the degree of the proteolysis and its inhibition was different with various Histones. The results indicate that all the Histones studied bind strongly to the negatively charged DNA and to the Actin filaments.

PARN loss-of-function mutations cause a severe form of the hereditary disease dyskeratosis congenita (DC). PARN deficiency affects the stability of non-coding RNAs such as human telomerase RNA (hTR), but these effects do not explain the severe disease in patients. We demonstrate that PARN deficiency affects the levels of numerous miRNAs in human cells. PARN regulates miRNA levels by stabilizing either mature or precursor miRNAs by removing oligo(A) tails added by the poly(A) polymerase PAPD5, which if remaining recruit the exonuclease DIS3L or DIS3L2 to degrade the miRNA. PARN knockdown destabilizes multiple miRNAs that repress p53 translation, which leads to an increase in p53 accumulation in a Dicer-dependent manner, thus explaining why PARN-defective patients show p53 accumulation. This work also reveals that DIS3L and DIS3L2 are critical 3' to 5' exonucleases that regulate miRNA stability, with the addition and removal of 3' end extensions controlling miRNA levels in the cell.

Stress granules and P-bodies are conserved assemblies of nontranslating mRNAs in eukaryotic cells that can be related to RNA–protein aggregates found in some neurodegenerative diseases. Herein, we examine how the Hsp70/Hsp40 protein chaperones affected the assembly and disassembly of stress granules and P-bodies in yeast. We observed that Hsp70 and the Ydj1 and Sis1 Hsp40 proteins accumulated in stress granules and defects in these proteins led to decreases in the disassembly and/or clearance of stress granules. We observed that individual Hsp40 proteins have different effects on stress granules with defects in Ydj1 leading to accumulation of stress granules in the vacuole and limited recovery of translation following stress, which suggests that Ydj1 promotes disassembly of stress granules to promote translation. In contrast, defects in Sis1 did not affect recovery of translation, accumulated cytoplasmic stress granules, and showed reductions in the targeting of stress granules to the vacuole. This demonstrates a new principle whereby alternative disassembly machineries lead to different fates of components within stress granules, thereby providing additional avenues for regulation of their assembly, composition, and function. Moreover, a role for Hsp70 and Hsp40 proteins in stress granule disassembly couples the assembly of these stress responsive structures to the proteostatic state of the cell.

Host defense peptides are effector molecules of the innate immunity that possess antimicrobial and health-promoting properties. Due to their potential therapeutic activities, host defense peptides are being explored as alternatives for antibiotics. The human LL-37 and its shorter, cost-effective, bactericidal core peptide derivates have been suggested for their therapeutic potential. Bacteria evade host defense peptides by proteolytic inactivation. Actin released from necrotized cells and abundant in infected sites was shown to bind and protect LL-37 from microbial proteolytic degradation, and to enable the peptide’s antimicrobial action despite the presence of the proteases. Here, we characterized the interactions of the 10–13 residues long LL-37 core peptides with actin. We show that the LL-37 core peptides associate with actin with a lower affinity than that of LL-37. Their association with actin, which is very ionic strength sensitive, is mainly based on electrostatic interactions. Likewise, the antimicrobial activity against Escherichia coli of the minimal antimicrobial peptide KR-12 but not FK-13 nor LL-37 is also very sensitive to salts. In addition, the antimicrobial activity of the FK-13 core peptide is protected by actin against the tested bacterial proteases in a similar manner to that of LL-37, supporting its potential for therapeutic use.

Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones. We showed that both histone mixture (histone type III) and the recombinant H2A histone bundles F-actin, increases the viscosity of the F-actin containing solution and polymerizes G-actin. The histone-actin bundles are relatively insensitive to increase of ionic strength, unlike other polycation, histatin, lysozyme, spermine and LL-37 induced F-actin bundles. The histone-actin bundles dissociate completely only in the presence of 300-400 mM NaCl. DNA, which competes with F-actin for histones, disassembles histone induced actin bundles. DNase1, which depolymerizes F- to G-actin, actively unbundles the H2A histone induced but slightly affects the histone mixture induced actin bundles. Cofilin decreases the amount of F-actin sedimented by low speed centrifugation, increases light scattering and viscosity of F-actin-histone mixture containing solutions and forms star like superstructures by copolymerizing G-actin with H2A histone. The results indicate that histones are tightly attached to F-actin by strong electrostatic and hydrophobic forces. Since both histones and F-actin are present in the sputum of patients with cystic fibrosis, therefore, the formation of the stable histone-actin bundles can contribute to the pathology of this disease by increasing the viscosity of the sputum. The actin-histone interaction in the nucleus might affect gene expression.

The evolutionarily conserved Lsm1-7-Pat1 complex is the most critical activator of mRNA decapping in eukaryotic cells and plays many roles in normal decay, AU-rich element-mediated decay, and miRNA silencing, yet how Pat1 interacts with the Lsm1-7 complex is unknown. Here, we show that Lsm2 and Lsm3 bridge the interaction between the C-terminus of Pat1 (Pat1C) and the Lsm1-7 complex. The Lsm2-3-Pat1C complex and the Lsm1-7-Pat1C complex stimulate decapping in vitro to a similar extent and exhibit similar RNA-binding preference. The crystal structure of the Lsm2-3-Pat1C complex shows that Pat1C binds to Lsm2-3 to form an asymmetric complex with three Pat1C molecules surrounding a heptameric ring formed by Lsm2-3. Structure-based mutagenesis revealed the importance of Lsm2-3-Pat1C interactions in decapping activation in vivo. Based on the structure of Lsm2-3-Pat1C, a model of Lsm1-7-Pat1 complex is constructed and how RNA binds to this complex is discussed.

Histones are small polycationic proteins located in the cell nucleus. Together, DNA and histones are integral constituents of the nucleosomes. Upon apoptosis, necrosis, and infection – induced cell death, histones are released from the cell. The extracellular histones have strong antimicrobial activity but are also cytotoxic and thought as mediators of cell death in sepsis. The antimicrobial activity of the cationic extracellular histones is inhibited by the polyanionic DNA and F-actin, which also become extracellular upon cell death. DNA and F-actin protect histones from degradation by the proteases of Pseudomonas aeruginosa and Porphyromonas gingivalis. However, though the integrity of the histones is protected, the activity of histones as antibacterial agents is lost. The inhibition of the histone’s antibacterial activity and their protection from proteolysis by DNA and F-actin indicate a tight electrostatic interaction between the positively charged histones and negatively charged DNA and F-actin, which may have physiological significance in maintaining the equilibrium between the beneficial antimicrobial activity of extracellular histones and their cytotoxic effects.

The objective of this paper is the analysis of road safety management in European countries and the identification of “good practice”. A road safety management investigation model was created, based on several “good practice” criteria. Road safety management systems have been thoroughly investigated in 14 European countries on 2010, by means of interviews with both governmental representatives and independent experts, who filled in an extensive questionnaire. A reliable and accurate picture (“profile”) was created for each country, allowing country comparisons. Then, statistical methods were used to make rankings of countries, and analyse the relationship between road safety management and road safety performance. The results of the analyses suggest that it is not possible to identify one single “good practice”. Nevertheless, there were several elements that emerged as “good practice” criteria. On the basis of the results, recommendations are proposed at national and European level.

The objective of this research is the assessment of current needs for evidence-based road safety decision making in Europe, through the consultation of a panel of road safety experts. The members of this Experts Panel have extensive knowledge of road safety management processes and needs in their country, being either directly involved in decision making, or working closely with decision makers. Two consultation methods were implemented: semi-directive interviews and written contributions. The synthesis of the results was carried out by means of a predefined matrix, in which the road safety management tasks were separated into their components, and were then cross-tabulated with distinct categories of needs. The results provide valuable information on the current and future needs for evidence-based road safety management in Europe. A number of key issues were brought forward with wide consensus among Experts, such as the need to make the consideration of scientific evidence in road safety decisions compulsory in all countries. The establishment of appropriate procedures was emphasized, including institutional arrangements for road safety management, with the necessary links and interactive procedures for local needs. The results also include useful recommendations, for the setting of targets, the use of cost-benefit analyses, the analysis of combined effects of measures, the collection of data on measures implementation, the collection of exposure and behavioural data, the estimation of injury under-reporting and the standardization of analysis methods.

Three polycations, polylysine, the polyamine spermine and the polycationic protein lysozyme were used to study the formation, structure, ionic strength sensitivity and dissociation of polycation-induced actin bundles. Bundles form fast, simultaneously with the polymerization of MgATP-G-actins, upon the addition of polycations to solutions of actins at low ionic strength conditions. This indicates that nuclei and/or nascent filaments bundle due to attractive, electrostatic effect of polycations and the neutralization of repulsive interactions of negative charges on actin. The attractive forces between the filaments are strong, as shown by the low (in nanomolar range) critical concentration of their bundling at low ionic strength. These bundles are sensitive to ionic strength and disassemble partially in 100 mM NaCl, but both the dissociation and ionic strength sensitivity can be countered by higher polycation concentrations. Cys374 residues of actin monomers residing on neighboring filaments in the bundles can be cross-linked by the short span (5.4 A) MTS-1 (1,1-Methanedyl Bismethanethiosulfonate) cross-linker, which indicates a tight packing of filaments in the bundles. The interfilament cross-links, which connect monomers located on oppositely oriented filaments, prevent disassembly of bundles at high ionic strength. Cofilin and the polysaccharide polyanion heparin disassemble lysozyme induced actin bundles more effectively than the polylysine-induced bundles. The actin-lysozyme bundles are pathologically significant as both proteins are found in the pulmonary airways of cystic fibrosis patients. Their bundles contribute to the formation of viscous mucus, which is the main cause of breathing difficulties and eventual death in this disorder.