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BACKGROUND: Anti-inflammatory effects of tranexamic acid (TXA) in reducing trauma endotheliopathy may protect from acute lung injury. Clinical data showing this benefit in trauma patients is lacking. We hypothesized that TXA administration mitigates pulmonary complications in penetrating trauma patients. MATERIALS AND METHODS: This is a post-hoc analysis of a multicenter, prospective, observational study of adults (18+ years) with penetrating torso and/or proximal extremity injury presenting at 25 urban trauma centers. Tranexamic acid administration in the prehospital setting or within three hours of admission was examined. Participants were propensity matched to compare similarly injured patients. The primary outcome was development of pulmonary complication (ARDS and/or pneumonia). RESULTS: A total of 2382 patients were included, and 206 (8.6%) received TXA. Of the 206, 93 (45%) received TXA prehospital and 113 (55%) received it within three hours of hospital admission. Age, sex, and incidence of massive transfusion did not differ. The TXA group was more severely injured, more frequently presented in shock (SBP < 90 mmHg), developed more pulmonary complications, and had lower survival (P < 0.01 for all). After propensity matching, 410 patients remained (205 in each cohort) with no difference in age, sex, or rate of shock. On logistic regression, increased emergency department heart rate was associated with pulmonary complications. Tranexamic acid was not associated with different rate of pulmonary complications or survival on logistic regression. Survival was not different between the groups on logistic regression or propensity score-matched analysis. CONCLUSIONS: Tranexamic acid administration is not protective against pulmonary complications in penetrating trauma patients.
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BACKGROUND: Mild cognitive impairment (MCI) is a pre-clinical stage of Alzheimer's disease (AD). Understanding the transition probabilities across the disease continuum of AD, ranging from MCI to AD to Mortality is crucial for the economic modeling of AD and effective planning of future interventions and healthcare resource allocation decisions. This study uses the Multi-state Markov model to quantify the transition probabilities along the disease progression and specifically investigates medications as modifiable risk factors of AD associated with accelerated or decelerated transition times from MCI to AD, MCI to mortality, and AD to mortality. METHODS: Individuals with MCI were identified from the National Alzheimer's Coordinating Center between September 2005 and May 2021. A three-state Markov model was postulated to model the disease progression among three states: MCI, AD, and mortality with adjustment for demographics, genetic characteristics, comorbidities and medications. Transition probabilities, the total length of stay in each state, and the hazard ratios of the use of medications for diabetes, hypertension, and hypercholesterolemia (the known modifiable risk factors of AD) were evaluated for these transitions. RESULTS: 3,324 individuals with MCI were identified. The probability of developing AD after one year since the initial diagnosis of MCI is 14.9%. After approximately 6 years from the initial diagnosis of MCI, the probability of transitioning to AD increases to nearly 41.7% before experiencing a subsequent decline. The expected total lengths of stay were 5.38 (95% CI: 0.002-6.03) years at MCI state and 7.61 (95%CI: 0.002-8.88) years at AD state. Patients with active use of lipid-lowering agents were associated with significantly lower hazards of transitioning from MCI to AD (HR: 0.83, 95%CI:0.71-0.96), MCI to mortality (HR: 0.51, 95%CI:0.34-0.77), and AD to mortality (HR: 0.81, 95%CI:0.66-0.99). CONCLUSIONS: Results suggest that lipid-lowering agents may confer a protective effect, delaying the onset of AD. Additionally, lipid-lowering agents indicate a favorable association with a longer survival time.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Progresión de la Enfermedad , Humanos , Enfermedad de Alzheimer/epidemiología , Enfermedad de Alzheimer/tratamiento farmacológico , Disfunción Cognitiva/epidemiología , Masculino , Femenino , Anciano , Factores de Riesgo , Anciano de 80 o más Años , Cadenas de MarkovRESUMEN
Biomolecular condensates can influence cellular function in a number of ways, including by changing the structural dynamics and conformational equilibria of the molecules partitioned within them. Here we use methyl transverse relaxation optimized spectroscopy (methyl-TROSY) NMR in conjunction with 2'-O-methyl labeling of RNA to characterize the thermodynamics and kinetics of RNA-RNA base pairing in condensates formed by the C-terminal intrinsically disordered region of CAPRIN1, an RNA-binding protein involved in RNA transport, translation, and stability. CAPRIN1 condensates destabilize RNA-RNA base pairing, resulting from a â¼270-fold decrease and a concomitant â¼15-fold increase in the on- and off-rates for duplex formation, respectively. The â¼30-fold slower diffusion of RNA single strands within the condensed phase partially accounts for the reduced on-rate, but the further â¼9-fold reduction likely reflects shedding of CAPRIN1 chains that are interacting with the RNA prior to hybridization. Our study emphasizes the important role of protein solvation in modulating nucleic acid recognition processes inside condensates.
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Hibridación de Ácido Nucleico , ARN , Termodinámica , ARN/química , Cinética , Conformación de Ácido Nucleico , Emparejamiento Base , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/metabolismo , Separación de FasesRESUMEN
NMR spectroscopy is an important tool for the measurement of the electrostatic properties of biomolecules. To this point, paramagnetic relaxation enhancements (PREs) of 1H nuclei arising from nitroxide cosolutes in biomolecular solutions have been used to measure effective near-surface electrostatic potentials (ÏENS) of proteins and nucleic acids. Here, we present a gadolinium (Gd)-based NMR method, exploiting Gd chelates with different net charges, for measuring ÏENS values and demonstrate its utility through applications to a number of biomolecular systems. The use of Gd-based cosolutes offers several advantages over nitroxides for ÏENS measurements. First, unlike nitroxide compounds, Gd chelates enable electrostatic potential measurements on oxidation-sensitive proteins that require reducing agents. Second, the large electron spin quantum number of Gd (7/2) results in notably larger PREs for Gd chelates when used at the same concentrations as nitroxide radicals. Thus, it is possible to measure ÏENS values exclusively from + and - charged compounds even for highly charged biomolecules, avoiding the use of neutral cosolutes that, as we further establish here, limits the accuracy of the measured electrostatic potentials. In addition, the smaller concentrations of cosolutes required minimize potential binding to sites on macromolecules. Fourth, the closer proximity of the paramagnetic center and charged groups within Gd chelates, in comparison to the corresponding nitroxide compounds, enables more accurate predictions of ÏENS potentials for cross-validation of the experimental results. The Gd-based method described here, thus, broadens the applicability of studies of biomolecular electrostatics using solution NMR spectroscopy.
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Gadolinio , Electricidad Estática , Gadolinio/química , Proteínas/química , Propiedades de Superficie , Resonancia Magnética Nuclear Biomolecular , Quelantes/química , Espectroscopía de Resonancia Magnética/métodosRESUMEN
The determination of a protein's structure is often a first step towards the development of a mechanistic understanding of its function. Considerable advances in computational protein structure prediction have been made in recent years, with AlphaFold2 (AF2) emerging as the primary tool used by researchers for this purpose. While AF2 generally predicts accurate structures of folded proteins, we present here a case where AF2 incorrectly predicts the structure of a small, folded and compact protein with high confidence. This protein, pro-interleukin-18 (pro-IL-18), is the precursor of the cytokine IL-18. Interestingly, the structure of pro-IL-18 predicted by AF2 matches that of the mature cytokine, and not the corresponding experimentally determined structure of the pro-form of the protein. Thus, while computational structure prediction holds immense promise for addressing problems in protein biophysics, there is still a need for experimental structure determination, even in the context of small well-folded, globular proteins.
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Resonancia Magnética Nuclear Biomolecular , Pliegue de Proteína , Resonancia Magnética Nuclear Biomolecular/métodos , Conformación Proteica , Modelos Moleculares , Proteínas/química , Algoritmos , Interleucina-18/química , Programas InformáticosRESUMEN
In 2015, the VIRTUS helmet was introduced to UK Armed Forces and will ultimately replace the Mark 7 combat helmet. The VIRTUS helmet has a reduced trimline compared to the Mark 7 helmet and can incorporate attachments such as a visor, mandible guard and nape protection. An anonymous questionnaire was provided to 200 UK Armed Forces personnel deployed to four locations on Operation TORAL in Afghanistan between September and October 2019. This is the first User feedback survey assessing the VIRTUS helmet in an operational environment. Users were measured to ascertain the fit of their helmet and asked to rate perceived helmet mass and comfort using a 5-point Likert scale. Users were also asked whether the VIRTUS helmet was better than previous helmets and about their use of the nape protection. The VIRTUS helmet was perceived to be an improvement over previously issued UK combat helmets in terms of both comfort and mass.
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Dispositivos de Protección de la Cabeza , Personal Militar , Humanos , Reino Unido , Personal Militar/psicología , Encuestas y Cuestionarios , Masculino , Adulto , Diseño de Equipo , Campaña Afgana 2001- , Femenino , Afganistán , Adulto Joven , Comportamiento del Consumidor , RetroalimentaciónRESUMEN
OBJECTIVES: To identify personal, clinical, and environmental factors associated with 4 previously identified distinct multidimensional participation profiles of individuals following traumatic brain injury (TBI). SETTING: Community. PARTICIPANTS: Participants (n = 408) enrolled in the TBI Model Systems (TBIMS) Participation Module, all 1 year or more postinjury. DESIGN: Secondary data analysis of cross-sectional data from participants in a multicenter TBIMS module study on participation conducted between May 2006 and September 2007. Participants provided responses to questionnaires via a telephone interview at their study follow-up (1, 2, 5, 10, or 15 years postinjury). MAIN MEASURES: Participants provided responses to personal (eg, demographic), clinical (eg, function), environmental (eg, neighborhood type), and participation measures to create multidimensional participation profiles. Data from measures collected at the time of injury (preinjury questionnaire, injury characteristics) were also included. The primary outcome was assignment to one of 4 multidimensional participation profile groups based on participation frequency, importance, satisfaction, and enfranchisement. The measures used to develop the profiles were: Participation Assessment with Recombined Tools-Objective, Importance, and Satisfaction scores, each across 3 domains (Productivity, Social Relationships, Out and About in the Community) and the Enfranchisement Scale (contributing to one's community, feeling valued by the community, choice and control). RESULTS: Results of the multinomial regression analysis, with 4 distinct participation profile groups as the outcome, indicated that education, current employment, current illicit drug use, current driving status, community type, and Functional Independence Measure Cognitive at follow-up significantly distinguished participation profile groups. Findings suggest a trend toward differences in participation profile groups by race/Hispanic ethnicity. CONCLUSIONS: Understanding personal, clinical, and environmental factors associated with distinct participation outcome profiles following TBI may provide more personalized and nuanced guidance to inform rehabilitation intervention planning and/or ongoing clinical monitoring.
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Burn survivors can experience social participation challenges throughout their recovery. The aim of this study was to develop a novel Australian English translation of the Life Impact Burn Recovery Evaluation (LIBRE) Profile, the Aus-LIBRE Profile. This study consisted of three stages: 1) translation of the LIBRE Profile from American to Australian English by Australian researchers/burns clinicians; 2) piloting and cognitive evaluation of the Aus-LIBRE Profile with burn survivors to assess the clarity and consistency of the interpretation of each individual item, and 3) review of the Aus-LIBRE Profile by colleagues who identify as Aboriginal Australians for cross-cultural validation. In stage 2, investigators administered the translated questionnaire to 20 Australian patients with burn injuries in the outpatient clinic (10 patients from xx and 10 patients from yy). Face validity of the Aus-LIBRE Profile was tested in 20 burns survivors (11 females) ranging from 21 to 74 years (median age 43 years). The total body surface area (TBSA) burned ranged from 1% to 50% (median 10%). Twelve language changes were made based on the feedback from the burn clinicians/researchers, study participants and colleagues who identify as Aboriginal Australians. Using a formal translation process, the Aus-LIBRE Profile was adapted for use in the Australian burn population. The Aus-LIBRE Profile will require psychometric validation and testing in the Australian burn patient population before broader application of the scale.
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Several interleukin-1 (IL-1) family members, including IL-1ß and IL-18, require processing by inflammasome-associated caspases to unleash their activities. Here, we unveil, by cryoelectron microscopy (cryo-EM), two major conformations of the complex between caspase-1 and pro-IL-18. One conformation is similar to the complex of caspase-4 and pro-IL-18, with interactions at both the active site and an exosite (closed conformation), and the other only contains interactions at the active site (open conformation). Thus, pro-IL-18 recruitment and processing by caspase-1 is less dependent on the exosite than the active site, unlike caspase-4. Structure determination by nuclear magnetic resonance uncovers a compact fold of apo pro-IL-18, which is similar to caspase-1-bound pro-IL-18 but distinct from cleaved IL-18. Binding sites for IL-18 receptor and IL-18 binding protein are only formed upon conformational changes after pro-IL-18 cleavage. These studies show how pro-IL-18 is selected as a caspase-1 substrate, and why cleavage is necessary for its inflammatory activity.
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Caspasa 1 , Microscopía por Crioelectrón , Interleucina-18 , Transducción de Señal , Interleucina-18/metabolismo , Caspasa 1/metabolismo , Humanos , Inflamasomas/metabolismo , Animales , Conformación Proteica , Unión Proteica , Sitios de Unión , Ratones , Receptores de Interleucina-18/metabolismo , Modelos Moleculares , Péptidos y Proteínas de Señalización IntercelularRESUMEN
OBJECTIVE: To examine the moderation effects of daily behavior on the associations between symptoms and social participation outcomes after burn injury. DESIGN: A 6-month prospective cohort study. SETTING: Community. PARTICIPANTS: Twenty-four adult burn survivors. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Symptoms and social participation outcomes were assessed weekly using smartphone surveys, including symptoms of pain (Patient-Reported Outcomes Measurement Information System [PROMIS] Pain Intensity and Pain Interference), anxiety (PROMIS Anxiety), and depression (Patient Health Questionnaire), as well as outcomes of social interactions and social activities (Life Impact Burn Recovery Evaluation [LIBRE] Social Interactions and Social Activities). Daily behaviors were automatically recorded by a smartphone application and smartphone logs, including physical activity (steps, travel miles, and activity minutes), sleep (sleep hours), and social contact (number of phone calls and message contacts). RESULTS: Multilevel models controlling for demographic and burn injury variables examined the associations between symptoms and social participation outcomes and the moderation effects of daily behaviors. Lower (worse) LIBRE Social Interactions and LIBRE Social Activities scores were significantly associated with higher (worse) PROMIS Pain Intensity, PROMIS Pain Interference, PROMIS Anxiety, and Patient Health Questionnaire-8 scores (P<.05). Additionally, daily steps and activity minutes were associated with LIBRE Social Interactions and LIBRE Social Activities (P<.05), and significantly moderated the association between PROMIS Anxiety and LIBRE Social Activities (P<.001). CONCLUSIONS: Social participation outcomes are associated with pain, anxiety, and depression symptoms after burn injury, and are buffered by daily physical activity. Future intervention studies should examine physical activity promotion to improve social recovery after burns.
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BACKGROUND: Despite the high incidence of blunt trauma in older adults, there is a lack of evidence-based guidance for computed tomography (CT) imaging in this population. We aimed to identify an algorithm to guide use of a Pan-Scan (Head/C-spine/Torso) or a Selective Scan (Head/C-spine ± Torso). We hypothesized that a patient's initial history and exam could be used to guide imaging. METHODS: We prospectively studied blunt trauma patients aged 65+ at 18 Level I/II trauma centers. Patients presenting >24 h after injury or who died upon arrival were excluded. We collected history and physical elements and final injury diagnoses. Injury diagnoses were categorized into CT body regions of Head/C-spine or Torso (chest, abdomen/pelvis, and T/L spine). Using machine learning and regression modeling as well as a priori clinical algorithms based, we tested various decision rules against our dataset. Our priority was to identify a simple rule which could be applied at the bedside, maximizing sensitivity (Sens) and negative predictive value (NPV) to minimize missed injuries. RESULTS: We enrolled 5,498 patients with 3,082 injuries. Nearly half (47.1%, n = 2,587) had an injury within the defined CT body regions. No rule to guide a Pan-Scan could be identified with suitable Sens/NPV for clinical use. A clinical algorithm to identify patients for Pan-Scan, using a combination of physical exam findings and specific high-risk criteria, was identified and had a Sens of 0.94 and NPV of 0.86 This rule would have identified injuries in all but 90 patients (1.6%) and would theoretically spare 11.9% (655) of blunt trauma patients a torso CT. CONCLUSIONS: Our findings advocate for Head/Cspine CT in all geriatric patients with the addition of torso CT in the setting of positive clinical findings and high-risk criteria. Prospective validation of this rule could lead to streamlined diagnostic care of this growing trauma population. LEVEL OF EVIDENCE: Level 2, Diagnostic Tests or Criteria.
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ABSTRACT: Trauma centers demonstrate an impressive ability to save lives, as reflected by inpatient survival rates of over 95% in the United States. Nevertheless, we fail to allocate sufficient effort and resources to ensure that survivors and their families receive the necessary care and support after leaving the trauma center. The objective of this scoping review is to systematically map the research on collaborative care models (CCM) that have been put forward to improve trauma survivorship. Of 833 articles screened, we included 16 studies evaluating eight collaborative care programs, predominantly in the U.S. The majority of the programs offered care coordination and averaged 9-months in duration. Three-fourths of the programs incorporated a mental health provider within their primary team. Observed outcomes were diverse: some models showed increased engagement (e.g., Center for Trauma Survivorship, trauma quality-of-life follow-up clinic), while others presented mixed mental health outcomes and varied results on pain and healthcare utilization. The findings of this study indicate that collaborative interventions may be effective in mental health screening, PTSD and depression management, effective referrals, and improving patient satisfaction with care. A consensus on core elements and cost-effectiveness of CCMs is necessary to set the standard for comprehensive care in post-trauma recovery.
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BACKGROUND: In patients with severe traumatic brain injury (TBI), clinicians must balance preventing venous thromboembolism (VTE) with the risk of intracranial hemorrhagic expansion (ICHE). We hypothesized that low molecular weight heparin (LMWH) would not increase risk of ICHE or VTE as compared to unfractionated heparin (UH) in patients with severe TBI. METHODS: Patients ≥ 18 years of age with isolated severe TBI (AIS ≥ 3), admitted to 24 level I and II trauma centers between January 1, 2014 to December 31, 2020 and who received subcutaneous UH and LMWH injections for chemical venous thromboembolism prophylaxis (VTEP) were included. Primary outcomes were VTE and ICHE after VTEP initiation. Secondary outcomes were mortality and neurosurgical interventions. Entropy balancing (EBAL) weighted competing risk or logistic regression models were estimated for all outcomes with chemical VTEP agent as the predictor of interest. RESULTS: 984 patients received chemical VTEP, 482 UH and 502 LMWH. Patients on LMWH more often had pre-existing conditions such as liver disease (UH vs LMWH 1.7 % vs. 4.4 %, p = 0.01), and coagulopathy (UH vs LMWH 0.4 % vs. 4.2 %, p < 0.001). There were no differences in VTE or ICHE after VTEP initiation. There were no differences in neurosurgical interventions performed. There were a total of 29 VTE events (3 %) in the cohort who received VTEP. A Cox proportional hazards model with a random effect for facility demonstrated no statistically significant differences in time to VTE across the two agents (p = 0.44). The LMWH group had a 43 % lower risk of overall ICHE compared to the UH group (HR = 0.57: 95 % CI = 0.32-1.03, p = 0.062), however was not statistically significant. CONCLUSION: In this multi-center analysis, patients who received LMWH had a decreased risk of ICHE, with no differences in VTE, ICHE after VTEP initiation and neurosurgical interventions compared to those who received UH. There were no safety concerns when using LMWH compared to UH. LEVEL OF EVIDENCE: Level III, Therapeutic Care Management.
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Anticoagulantes , Lesiones Traumáticas del Encéfalo , Heparina de Bajo-Peso-Molecular , Puntaje de Propensión , Tromboembolia Venosa , Humanos , Tromboembolia Venosa/prevención & control , Lesiones Traumáticas del Encéfalo/complicaciones , Masculino , Femenino , Persona de Mediana Edad , Anticoagulantes/uso terapéutico , Heparina de Bajo-Peso-Molecular/uso terapéutico , Adulto , Heparina/uso terapéutico , Estudios Retrospectivos , Anciano , Hemorragias IntracranealesRESUMEN
Solution NMR spectroscopy has tremendous potential for providing atomic resolution insights into the interactions between proteins and nucleic acids partitioned into condensed phases of phase-separated systems. However, the highly viscous nature of the condensed phase challenges applications, and in particular, the extraction of quantitative, site-specific information. Here, we present a delayed decoupling-based HMQC pulse sequence for methyl-TROSY studies of 'client' proteins and nucleic acids partitioned into 'scaffold' proteinaceous phase-separated solvents. High sensitivity and excellent quality spectra are recorded of a nascent form of superoxide dismutase and of a small RNA fragment partitioned into CAPRIN1 condensates.
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Resonancia Magnética Nuclear Biomolecular , ARN , ARN/química , Resonancia Magnética Nuclear Biomolecular/métodos , Pliegue de Proteína , Proteínas/química , Superóxido Dismutasa/química , Condensados Biomoleculares/química , AlgoritmosRESUMEN
The objective of this investigation was to evaluate the influence of micro- and nanoplastic particles composed of polyethylene terephthalate (PET), a significant contributor to plastic pollution, on human brain vascular pericytes. Specifically, we delved into their impact on mitochondrial functionality, oxidative stress, and the expression of genes associated with oxidative stress, ferroptosis and mitochondrial functions. Our findings demonstrate that the exposure of a monoculture of human brain vascular pericytes to PET particles in vitro at a concentration of 50 µg/ml for a duration of 3, 6 and 10 days did not elicit oxidative stress. Notably, we observed a reduction in various aspects of mitochondrial respiration, including maximal respiration, spare respiratory capacity, and ATP production in pericytes subjected to PET particles for 3 days, with a mitochondrial function recovery at 6 and 10 days. Furthermore, there were no statistically significant alterations in mitochondrial DNA copy number, or in the expression of genes linked to oxidative stress and ferroptosis, but an increase of the expression of the gene mitochondrial transcription factor A (TFAM) was noted at 3 days exposure. These outcomes suggest that, at a concentration of 50 µg/ml, PET particles do not induce oxidative stress in human brain vascular pericytes. Instead, at 3 days exposure, PET exposure impairs mitochondrial functions, but this is recovered at 6-day exposure. This seems to indicate a potential mitochondrial hormesis response (mitohormesis) is incited, involving the gene TFAM. Further investigations are warranted to explore the stages of mitohormesis and the potential consequences of plastics on the integrity of the blood-brain barrier and intercellular interactions. This research contributes to our comprehension of the potential repercussions of nanoplastic pollution on human health and underscores the imperative need for ongoing examinations into the exposure to plastic particles.
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Encéfalo , Mitocondrias , Estrés Oxidativo , Pericitos , Tereftalatos Polietilenos , Humanos , Estrés Oxidativo/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Pericitos/efectos de los fármacos , Pericitos/metabolismo , Encéfalo/metabolismo , Encéfalo/irrigación sanguínea , Encéfalo/efectos de los fármacos , Nanopartículas , Microplásticos/toxicidad , Células CultivadasRESUMEN
A critical feature of the cellular antioxidant response is the induction of gene expression by redox-sensitive transcription factors. In many cells, activating these transcription factors is a dynamic process involving multiple redox steps, but it is unclear how these dynamics should be measured. Here, we show how the dynamic profile of the Schizosaccharomyces pombe Pap1 transcription factor is quantifiable by three parameters: signal amplitude, signal time and signal duration. In response to increasing hydrogen peroxide concentrations, the Pap1 amplitude decreased while the signal time and duration showed saturable increases. In co-response plots, these parameters showed a complex, non-linear relationship to the mRNA levels of four Pap1-regulated genes. We also demonstrate that hydrogen peroxide and tert-butyl hydroperoxide trigger quantifiably distinct Pap1 activation profiles and transcriptional responses. Based on these findings, we propose that different oxidants and oxidant concentrations modulate the Pap1 dynamic profile, leading to specific transcriptional responses. We further show how the effect of combination and pre-exposure stresses on Pap1 activation dynamics can be quantified using this approach. This method is therefore a valuable addition to the redox signalling toolbox that may illuminate the role of dynamics in determining appropriate responses to oxidative stress.
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Peróxido de Hidrógeno , Oxidación-Reducción , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Transducción de Señal , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Schizosaccharomyces/metabolismo , Schizosaccharomyces/genética , Peróxido de Hidrógeno/metabolismo , terc-Butilhidroperóxido/farmacología , Proteínas Asociadas a Pancreatitis/metabolismo , Proteínas Asociadas a Pancreatitis/genética , Regulación Fúngica de la Expresión Génica , Estrés Oxidativo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Oxidantes/farmacología , Oxidantes/metabolismoRESUMEN
BACKGROUND: Andexanet Alfa (AA) is the only FDA approved reversal agent for apixaban and rivaroxaban (DOAC). There are no studies comparing its efficacy with 4-Factor Prothrombin Complex Concentrate (PCC). This study aimed to compare PCC to AA for DOAC reversal, hypothesizing non-inferiority of PCC. METHODS: We performed a retrospective, non-inferiority multicenter study of adult patients admitted from July 1, 2018 to December 31, 2019 who had taken a DOAC within 12 hours of injury, were transfused red blood cells (RBCs) or had traumatic brain injury, and received AA or PCC. Primary outcome was PRBC unit transfusion. Secondary outcome with ICU length of stay. MICE imputation was used to account for missing data and zero-inflated poisson regression was used to account for an excess of zero units of RBC transfused. 2 Units difference in RBC transfusion was selected as non-inferior. RESULTS: Results: From 263 patients at 10 centers, 77 (29%) received PCC and 186 (71%) AA. Patients had similar transfusion rates across reversal treatment groups (23.7% AA vs 19.5% PCC) with median transfusion in both groups of 0 RBC. According to the Poisson component, PCC increases the amount of RBC transfusion by 1.02 times (95% CI: 0.79-1.33) compared to AA after adjusting for other covariates. The averaged amount of RBC transfusion (non-zero group) is 6.13. Multiplying this number by the estimated rate ratio, PCC is estimated to have an increase RBC transfusion by 0.123 (95% CI: 0.53-2.02) units compared to AA. CONCLUSION: PCC appears non-inferior to AA for reversal of DOACs for RBC transfusion in traumatically injured patients. Additional prospective, randomized trials are necessary to compare PCC and AA for the treatment of hemorrhage in injured patients on DOACs. LEVEL OF EVIDENCE: Therapeutic/Care Management, Level III.
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Segments of proteins with high ß-strand propensity can self-associate to form amyloid fibrils implicated in many diseases. We describe a general approach to bind such segments in ß-strand and ß-hairpin conformations using de novo designed scaffolds that contain deep peptide-binding clefts. The designs bind their cognate peptides in vitro with nanomolar affinities. The crystal structure of a designed protein-peptide complex is close to the design model, and NMR characterization reveals how the peptide-binding cleft is protected in the apo state. We use the approach to design binders to the amyloid-forming proteins transthyretin, tau, serum amyloid A1 and amyloid ß1-42 (Aß42). The Aß binders block the assembly of Aß fibrils as effectively as the most potent of the clinically tested antibodies to date and protect cells from toxic Aß42 species.
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Péptidos beta-Amiloides , Humanos , Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/metabolismo , Unión Proteica , Péptidos/química , Péptidos/farmacología , Amiloide/química , Amiloide/metabolismo , Modelos Moleculares , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Diseño de Fármacos , Proteínas Amiloidogénicas/química , Proteínas Amiloidogénicas/metabolismo , Proteínas tau/metabolismo , Proteínas tau/química , Prealbúmina/química , Prealbúmina/metabolismo , Secuencia de AminoácidosRESUMEN
The DegP protease-chaperone operates within the periplasm of Gram-negative bacteria, where it assists in the regulation of protein homeostasis, promotes virulence, and is essential to survival under stress. To carry out these tasks, DegP forms a network of preorganized apo oligomers that facilitate the capture of substrates within distributions of cage-like complexes which expand to encapsulate clients of various sizes. Although the architectures of DegP cage complexes are well understood, little is known about the structures, dynamics, and interactions of client proteins within DegP cages and the relationship between client structural dynamics and function. Here, we probe host-guest interactions within a 600 kDa DegP cage complex throughout the DegP activation cycle using a model α-helical client protein through a combination of hydrodynamics measurements, methyl-transverse relaxation optimized spectroscopy-based solution nuclear magnetic resonance studies, and proteolytic activity assays. We find that in the presence of the client, DegP cages assemble cooperatively with few intermediates. Our data further show that the N-terminal half of the bound client, which projects into the interior of the cages, is predominantly unfolded and flexible, and exchanges between multiple conformational states over a wide range of time scales. Finally, we show that a concerted structural transition of the protease domains of DegP occurs upon client engagement, leading to activation. Together, our findings support a model of DegP as a highly cooperative and dynamic molecular machine that stabilizes unfolded states of clients, primarily via interactions with their C-termini, giving rise to efficient cleavage.
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Proteínas de Choque Térmico , Hidrodinámica , Proteínas Periplasmáticas , Serina Endopeptidasas , Humanos , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/metabolismo , Chaperonas Moleculares/metabolismo , Espectroscopía de Resonancia MagnéticaRESUMEN
Objectives: There is little evidence guiding the management of grade I-II traumatic splenic injuries with contrast blush (CB). We aimed to analyze the failure rate of nonoperative management (NOM) of grade I-II splenic injuries with CB in hemodynamically stable patients. Methods: A multicenter, retrospective cohort study examining all grade I-II splenic injuries with CB was performed at 21 institutions from January 1, 2014, to October 31, 2019. Patients >18 years old with grade I or II splenic injury due to blunt trauma with CB on CT were included. The primary outcome was the failure of NOM requiring angioembolization/operation. We determined the failure rate of NOM for grade I versus grade II splenic injuries. We then performed bivariate comparisons of patients who failed NOM with those who did not. Results: A total of 145 patients were included. Median Injury Severity Score was 17. The combined rate of failure for grade I-II injuries was 20.0%. There was no statistical difference in failure of NOM between grade I and II injuries with CB (18.2% vs 21.1%, p>0.05). Patients who failed NOM had an increased median hospital length of stay (p=0.024) and increased need for blood transfusion (p=0.004) and massive transfusion (p=0.030). Five patients (3.4%) died and 96 (66.2%) were discharged home, with no differences between those who failed and those who did not fail NOM (both p>0.05). Conclusion: NOM of grade I-II splenic injuries with CB fails in 20% of patients. Level of evidence: IV.