84 research outputs found

    Anti-TNF-α antibody allows healing of joint damage in polyarthritic transgenic mice

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    Anti-tumor-necrosis-factor-α (TNF-α) monoclonal antibody was used to treat Tg197 transgenic mice, which constitutively produce human TNF-α (hTNF-α) and develop a progressive polyarthritic disease. Treatment of both young (7- or 8-week-old) and aged (27- or 28-week-old) mice commenced when at least two limbs showed signs of moderate to severe arthritis. The therapeutic efficacy of anti-TNF-α antibody was assessed using various pathological indicators of disease progression. The clinical severity of arthritis in Tg197 mice was significantly reduced after anti-TNF-α treatment in comparison with saline-treated mice and in comparison with baseline assessments in both young and aged mice. The treatment with anti-TNF-α prevented loss of body weight. Inflammatory pathways as reflected by elevated circulating hTNF-α and local expression of various proinflammatory mediators were all diminished by anti-TNF-α treatment, confirming a critical role of hTNF-α in this model of progressive polyarthritis. More importantly, the amelioration of the disease was associated with reversal of existing structural damage, including synovitis and periosteal bone erosions evident on histology. Repair of cartilage was age dependent: reversal of cartilage degradation after anti-TNF-α treatment was observed in young mice but not in aged mice

    Mechanically Ventilated COVID-19 Patients Admitted to the Intensive Care Unit in the United States With or Without Respiratory Failure Secondary to COVID-19 Pneumonia: A Retrospective Comparison of Characteristics and Outcomes

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    BACKGROUND: There is increasing heterogeneity in the clinical phenotype of patients admitted to the intensive care unit (ICU) with coronavirus disease 2019 (COVID-19,) and reasons for mechanical ventilation are not limited to COVID pneumonia. We aimed to compare the characteristics and outcomes of intubated patients admitted to the ICU with the primary diagnosis of acute hypoxemic respiratory failure (AHRF) from COVID-19 pneumonia to those patients admitted for an alternative diagnosis. METHODS: Retrospective cohort study of adults with confirmed SARS-CoV-2 infection admitted to nine ICUs between March 18, 2020, and April 30, 2021, at an urban university institution. We compared characteristics between the two groups using appropriate statistics. We performed logistic regression to identify risk factors for death in the mechanically ventilated COVID-19 population. RESULTS: After exclusions, the final sample consisted of 319 patients with respiratory failure secondary to COVID pneumonia and 150 patients intubated for alternative diagnoses. The former group had higher ICU and hospital mortality rates (57.7% vs. 36.7%, P CONCLUSIONS: Mechanically ventilated COVID-19 patients admitted to the ICU with COVID-19-associated respiratory failure are at higher risk of hospital death and have worse ICU utilization outcomes than those whose reason for admission is unrelated to COVID pneumonia

    Mechanically ventilated COVID-19 patients admitted to the intensive care unit in the United States with or without respiratory failure secondary to COVID-19 pneumonia: a retrospective comparison of characteristics and outcomes

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    Background There is increasing heterogeneity in the clinical phenotype of patients admitted to the intensive care unit (ICU) with coronavirus disease 2019 (COVID-19,) and reasons for mechanical ventilation are not limited to COVID pneumonia. We aimed to compare the characteristics and outcomes of intubated patients admitted to the ICU with the primary diagnosis of acute hypoxemic respiratory failure (AHRF) from COVID-19 pneumonia to those patients admitted for an alternative diagnosis. Methods Retrospective cohort study of adults with confirmed SARS-CoV-2 infection admitted to nine ICUs between March 18, 2020, and April 30, 2021, at an urban university institution. We compared characteristics between the two groups using appropriate statistics. We performed logistic regression to identify risk factors for death in the mechanically ventilated COVID-19 population. Results After exclusions, the final sample consisted of 319 patients with respiratory failure secondary to COVID pneumonia and 150 patients intubated for alternative diagnoses. The former group had higher ICU and hospital mortality rates (57.7% vs. 36.7%, P<0.001 and 58.9% vs. 39.3%, P<0.001, respectively). Patients with AHRF secondary to COVID-19 pneumonia also had longer ICU and hospital lengths-of-stay (12 vs. 6 days, P<0.001 and 20 vs. 13.5 days, P=0.001). After risk-adjustment, these patients had 2.25 times higher odds of death (95% confidence interval, 1.42–3.56; P=0.001). Conclusions Mechanically ventilated COVID-19 patients admitted to the ICU with COVID-19-associated respiratory failure are at higher risk of hospital death and have worse ICU utilization outcomes than those whose reason for admission is unrelated to COVID pneumonia

    Mutation of von Hippel–Lindau Tumour Suppressor and Human Cardiopulmonary Physiology

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    BACKGROUND: The von Hippel–Lindau tumour suppressor protein–hypoxia-inducible factor (VHL–HIF) pathway has attracted widespread medical interest as a transcriptional system controlling cellular responses to hypoxia, yet insights into its role in systemic human physiology remain limited. Chuvash polycythaemia has recently been defined as a new form of VHL-associated disease, distinct from the classical VHL-associated inherited cancer syndrome, in which germline homozygosity for a hypomorphic VHL allele causes a generalised abnormality in VHL–HIF signalling. Affected individuals thus provide a unique opportunity to explore the integrative physiology of this signalling pathway. This study investigated patients with Chuvash polycythaemia in order to analyse the role of the VHL–HIF pathway in systemic human cardiopulmonary physiology. METHODS AND FINDINGS: Twelve participants, three with Chuvash polycythaemia and nine controls, were studied at baseline and during hypoxia. Participants breathed through a mouthpiece, and pulmonary ventilation was measured while pulmonary vascular tone was assessed echocardiographically. Individuals with Chuvash polycythaemia were found to have striking abnormalities in respiratory and pulmonary vascular regulation. Basal ventilation and pulmonary vascular tone were elevated, and ventilatory, pulmonary vasoconstrictive, and heart rate responses to acute hypoxia were greatly increased. CONCLUSIONS: The features observed in this small group of patients with Chuvash polycythaemia are highly characteristic of those associated with acclimatisation to the hypoxia of high altitude. More generally, the phenotype associated with Chuvash polycythaemia demonstrates that VHL plays a major role in the underlying calibration and homeostasis of the respiratory and cardiovascular systems, most likely through its central role in the regulation of HIF

    Graphene and related materials in hierarchical fiber composites: Production techniques and key industrial benefits

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    Fiber-reinforced composites (FRC) are nowadays one of the most widely used class of high-tech materials. In particular, sporting goods, cars and the wings and fuselages of airplanes are made of carbon fiber reinforced composites (CFRC). CFRC are mature commercial products, but are still challenging materials. Their mechanical and electrical properties are very good along the fiber axis, but can be very poor perpendicular to it; interfacial interactions have to be tailored for specific applications to avoid crack propagation– and delamination; fiber production includes high-temperature treatments of adverse environmental impact, leading to high costs. Recent research work shows that the performance of CFRC can be improved by addition of graphene or related 2-dimensional materials (GRM). Graphene is a promising additive for CFRC because: 1) Its all-carbon aromatic structure is similar to the one of carbon fiber (CF). 2) Its 2-dimensional shape, high aspect ratio, high flexibility and mechanical strength allow it to be used as a coating on the surface of fiber, or as a mechanical/electrical connection between different fiber layers. 3) Its tunable surface chemistry allows its interaction to be enhanced with either the fiber or the polymer matrix used in the composite and 4) in contrast to carbon fibers or nanotubes, it is easily produced on a large scale at room temperature, without metal catalysts. Here, we summarize the key strategic advantages that could be obtained in this way, and some of the recent results that have been obtained in this field within the Graphene Flagship project and worldwide

    Clinical and Economic Evaluation of a Proteomic Biomarker Preterm Birth Risk Predictor: Cost-Effectiveness Modeling of Prenatal Interventions Applied to Predicted Higher-Risk Pregnancies Within a Large and Diverse Cohort

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    Objectives: Preterm birth occurs in more than 10% of U.S. births and is the leading cause of U.S. neonatal deaths, with estimated annual costs exceeding $25 billion USD. Using real-world data, we modeled the potential clinical and economic utility of a prematurity-reduction program comprising screening in a racially and ethnically diverse population with a validated proteomic biomarker risk predictor, followed by case management with or without pharmacological treatment. Methods: The ACCORDANT microsimulation model used individual patient data from a prespecified, randomly selected sub-cohort (N = 847) of a multicenter, observational study of U.S. subjects receiving standard obstetric care with masked risk predictor assessment (TREETOP; NCT02787213). All subjects were included in three arms across 500 simulated trials: standard of care (SoC, control); risk predictor/case management comprising increased outreach, education and specialist care (RP-CM, active); and multimodal management (risk predictor/case management with pharmacological treatment) (RP-MM, active). In the active arms, only subjects stratified as higher risk by the predictor were modeled as receiving the intervention, whereas lower-risk subjects received standard care. Higher-risk subjects\u27 gestational ages at birth were shifted based on published efficacies, and dependent outcomes, calibrated using national datasets, were changed accordingly. Subjects otherwise retained their original TREETOP outcomes. Arms were compared using survival analysis for neonatal and maternal hospital length of stay, bootstrap intervals for neonatal cost, and Fisher\u27s exact test for neonatal morbidity/mortality (significance, p \u3c .05). Results: The model predicted improvements for all outcomes. RP-CM decreased neonatal and maternal hospital stay by 19% (p = .029) and 8.5% (p = .001), respectively; neonatal costs\u27 point estimate by 16% (p = .098); and moderate-to-severe neonatal morbidity/mortality by 29% (p = .025). RP-MM strengthened observed reductions and significance. Point estimates of benefit did not differ by race/ethnicity. Conclusions: Modeled evaluation of a biomarker-based test-and-treat strategy in a diverse population predicts clinically and economically meaningful improvements in neonatal and maternal outcomes

    Origin of Axial and Radial Expansions in Carbon Nanotubes Revealed by Ultrafast Diffraction and Spectroscopy

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    The coupling between electronic and nuclear degrees of freedom in low-dimensional, nanoscale systems plays a fundamental role in shaping many of their properties. Here, we report the disentanglement of axial and radial expansions of carbon nanotubes, and the direct role of electronic and vibrational excitations in determining such expansions. With subpicosecond and subpicometer resolutions, structural dynamics were explored by monitoring changes of the electron diffraction following an ultrafast optical excitation, whereas the transient behavior of the charge distribution was probed by time-resolved, electron-energy-loss spectroscopy. Our experimental results, and supporting density functional theory calculations, indicate that a population of the excited carriers in the antibonding orbitals of the nanotube walls drives a transient axial deformation in ∼1 ps; this deformation relaxes on a much longer time scale, 17 ps, by nonradiative decay. The electron-driven expansion is distinct from the phonon-driven dynamics observed along the radial direction, using the characteristic Bragg reflections; it occurs in 5 ps. These findings reveal the nonequilibrium distortion of the unit cell at early times and the role of the electron(phonon)-induced stress in the lattice dynamics of one-dimensional nanostructures

    Hyaluronidase for Dermal Filler Complications: Review of Applications and Dosage Recommendations

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    BackgroundHyaluronidase (Hyal) can reverse complications of hyaluronic acid (HA) fillers, which has contributed substantially to the popularity of such procedures. Still, there are differing opinions regarding Hyal treatment, including dosage recommendations in filler complication management. ObjectiveWe aimed to address unanswered questions regarding Hyal treatment for HA filler complications, including timing and dosage, skin pretesting, properties of various Hyals and interactions with HA gels, and pitfalls of the treatment. MethodsPubMed and Google Scholar databases were searched from inception for articles on Hyal therapy for filler complications. Articles were evaluated regarding their contribution to the field. The extensive literature review includes international leaders’ suggestions and expert panels’ recommendations. ResultsThere are limited controlled data but increasing clinical experience with Hyal treatment. The currently used Hyals provide good results and have an acceptable safety profile. Nonemergent complications such as the Tyndall effect, noninflamed nodules, and allergic or hypersensitivity reactions should be treated with low or moderate Hyal doses. Hyal should be considered with prior or simultaneous oral antibiotic treatment in managing inflammatory nodules. Hyal may be tried for granulomas that have not responded to intralesional steroids. Emergent complications such as vascular occlusion and blindness require immediate, high-dose Hyal treatment. Regarding blindness, the injection technique, retrobulbar versus supraorbital, remains controversial. Ultrasound guidance can increase the efficacy of the above interventions. ConclusionsHyal is essential in aesthetic practice because it can safely treat most HA filler complications. Immediate Hyal treatment is required for emergent complications. Aesthetic practitioners should be versed in using Hyal and effective dosage protocols
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