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Single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST) are two emerging research technologies that uniquely characterize gene expression microenvironments on a cellular or subcellular level. The skin, a clinically accessible tissue composed of diverse, essential cell populations, serves as an ideal target for these high-resolution investigative approaches. Using these tools, researchers are assembling a compendium of data and discoveries in healthy skin as well as a range of dermatologic pathophysiologies, including atopic dermatitis, psoriasis, and cutaneous malignancies. The ongoing advancement of single-cell approaches, coupled with anticipated decreases in cost with increased adoption, will reshape dermatologic research, profoundly influencing disease characterization, prognosis, and ultimately clinical practice.
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Limited data exist in large, representative populations about whether the risk of thromboembolic events varies after receiving four-factor human prothrombin complex concentrate (4F-PCC) versus treatment with human plasma for urgent reversal of oral vitamin K antagonist therapy. We conducted a multicenter observational study to compare the 45-day risk of thromboembolic events in adults with warfarin-associated major bleeding after treatment with 4F-PCC (Kcentra®) or plasma. Hospitalized patients in two large integrated healthcare delivery systems who received 4F-PCC or plasma for reversal of warfarin due to major bleeding from January 1, 2008 to March 31, 2020 were identified and were matched 1:1 on potential confounders and a high-dimensional propensity score. Arterial and venous thromboembolic events were identified up to 45 days after receiving 4F-PCC or plasma from electronic health records and adjudicated by physician review. Among 1119 patients receiving 4F-PCC and a matched historical cohort of 1119 patients receiving plasma without a recent history of thromboembolism, mean (SD) age was 76.7 (10.5) years, 45.6% were women, and 9.4% Black, 14.6% Asian/Pacific Islander, and 15.7% Hispanic. The 45-day risk of thromboembolic events was 3.4% in those receiving 4F-PCC and 4.1% in those receiving plasma (P = 0.26; adjusted hazard ratio 0.76; 95% confidence interval 0.49-1.16). The adjusted risk of all-cause death at 45 days post-treatment was lower in those receiving 4F-PCC compared with plasma. Among a large, ethnically diverse cohort of adults treated for reversal of warfarin-associated bleeding, receipt of 4F-PCC was not associated with an excess risk of thromboembolic events at 45 days compared with plasma therapy.
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Tromboembolia Venosa , Varfarina , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/efeitos adversos , Fatores de Coagulação Sanguínea , Fator IX , Feminino , Hemorragia/induzido quimicamente , Humanos , Coeficiente Internacional Normatizado , Masculino , Estudos Retrospectivos , Tromboembolia Venosa/induzido quimicamente , Tromboembolia Venosa/tratamento farmacológico , Vitamina K , Varfarina/efeitos adversosRESUMO
This review of current literature demonstrates the psychological implications of skin conditions. Skin conditions of varying severity can impact the quality of patients' lives and have psychiatric consequences. This impact provides a need for healthcare providers to consider the psychological implications of one's skin conditions and their effect on quality of life. The psychological challenges that arise from varying skin conditions show the potential need for both dermatological and psychiatric interventions. The following literature review details the psychiatric consequences of skin conditions under various conditions. It first looks at literature highlighting the psychiatric consequences experienced through various age ranges, from adults to adolescents and children. The paper then explores multiple skin conditions and their psychological effect before highlighting some of the interactions that stress has on the skin that could further exacerbate one's condition. Finally, it examines how patients characterize their experience with their skin condition and goes into some clinical case studies of patients with psychological implications as a result of their skin disorder. The paper also highlights the magnitude of dermatologic patients experiencing psychological conditions in conjunction with their skin conditions.
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Transtornos Mentais , Dermatopatias , Adolescente , Adulto , Criança , Humanos , Qualidade de Vida , Dermatopatias/psicologiaRESUMO
Enhanced darkfield microscopy (EDFM) and hyperspectral imaging (HSI) are being evaluated as a potential rapid screening modality to reduce the time-to-knowledge for direct visualisation and analysis of filter media used to sample nanoparticulate from work environments, as compared to the current analytical gold standard of transmission electron microscopy (TEM). Here, we compare accuracy, specificity, and sensitivity of several hyperspectral classification models and data preprocessing techniques to determine how to most effectively identify multiwalled carbon nanotubes (MWCNTs) in hyperspectral images. Several classification schemes were identified that are capable of classifying pixels as MWCNT(+) or MWCNT(-) in hyperspectral images with specificity and sensitivity over 99% on the test dataset. Functional principal component analysis (FPCA) was identified as an appropriate data preprocessing technique, testing optimally when coupled with a quadratic discriminant analysis (QDA) model with forward stepwise variable selection and with a support vector machines (SVM) model. The success of these methods suggests that EDFM-HSI may be reliably employed to assess filter media exposed to MWCNTs. Future work will evaluate the ability of EDFM-HSI to quantify MWCNTs collected on filter media using this classification algorithm framework using the best-performing model identified here - quadratic discriminant analysis with forward stepwise selection on functional principal component data - on an expanded sample set.
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Celulose/química , Nanotubos de Carbono , Ésteres , Microscopia , Máquina de Vetores de SuporteRESUMO
This occupational exposure assessment study characterized potential inhalation exposures of workers to engineered nanomaterials associated with chemical mechanical planarization wafer polishing processes in a semiconductor research and development facility. Air sampling methodology was designed to capture airborne metal oxide nanoparticles for characterization. The research team obtained air samples in the fab and subfab areas using a combination of filter-based capture methods to determine particle morphology and elemental composition and real-time direct-reading instruments to determine airborne particle counts. Filter-based samples were analyzed by electron microscopy and energy-dispersive x-ray spectroscopy while real-time particle counting data underwent statistical analysis. Sampling was conducted during worker tasks associated with preventive maintenance and quality control that were identified as having medium to high potential for inhalation exposure based on qualitative assessments. For each sampling event, data was collected for comparison between the background, task area, and personal breathing zone. Sampling conducted over nine months included five discrete sampling series events in coordination with on-site employees under real working conditions. The number of filter-based samples captured was: eight from worker personal breathing zones; seven from task areas; and five from backgrounds. A complementary suite of direct-reading instruments collected data for seven sample collection periods in the task area and six in the background. Engineered nanomaterials of interest (Si, Al, Ce) were identified in filter-based samples from all areas of collection, existing as agglomerates (>500 nm) and nanoparticles (100-500 nm). Particle counts showed an increase in number concentration above background during a subset of the job tasks, but particle counts in the task areas were otherwise not significantly higher than background. Additional data is needed to support further statistical analysis and determine trends; however, this initial investigation suggests that nanoparticles used or generated by the wafer polishing process become aerosolized and may be accessible for inhalation exposures by workers performing tasks in the subfab and fab. Additional research is needed to further quantify the degree of exposure and link these findings to related hazard research.
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Poluentes Ocupacionais do Ar/análise , Nanopartículas Metálicas/análise , Exposição Ocupacional/análise , Semicondutores , Monitoramento Ambiental/métodos , Humanos , Exposição por Inalação/análise , Nanopartículas Metálicas/química , Óxidos/análise , Óxidos/química , Tamanho da Partícula , Local de TrabalhoRESUMO
The ubiquitous use of engineered nanomaterials-particulate materials measuring approximately 1-100 nanometers (nm) on their smallest axis, intentionally engineered to express novel properties-in semiconductor fabrication poses unique issues for protecting worker health and safety. Use of new substances or substances in a new form may present hazards that have yet to be characterized for their acute or chronic health effects. Uncharacterized or emerging occupational health hazards may exist when there is insufficient validated hazard data available to make a decision on potential hazard and risk to exposed workers under condition of use. To advance the knowledge of potential worker exposure to engineered nanomaterials, the National Institute for Occupational Safety and Health Nanotechnology Field Studies Team conducted an on-site field evaluation in collaboration with on-site researchers at a semiconductor research and development facility on April 18-21, 2011. The Nanomaterial Exposure Assessment Technique (2.0) was used to perform a complete exposure assessment. A combination of filter-based sampling and direct-reading instruments was used to identify, characterize, and quantify the potential for worker inhalation exposure to airborne alumina and amorphous silica nanoparticles associated with th e chemical mechanical planarization wafer polishing process. Engineering controls and work practices were evaluated to characterize tasks that might contribute to potential exposures and to assess existing engineering controls. Metal oxide structures were identified in all sampling areas, as individual nanoparticles and agglomerates ranging in size from 60 nm to >1,000 nm, with varying structure morphology, from long and narrow to compact. Filter-based samples indicated very little aerosolized material in task areas or worker breathing zone. Direct-reading instrument data indicated increased particle counts relative to background in the wastewater treatment area; however, particle counts were very low overall, indicating a well-controlled working environment. Recommendations for employees handling or potentially exposed to engineered nanomaterials include hazard communication, standard operating procedures, conservative ventilation systems, and prevention through design in locations where engineered nanomaterials are used or stored, and routine air sampling for occupational exposure assessment and analysis.
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Exposição por Inalação/análise , Nanopartículas Metálicas/análise , Exposição Ocupacional/análise , Semicondutores , Poluentes Ocupacionais do Ar/análise , Monitoramento Ambiental/métodos , Humanos , Nanotecnologia , National Institute for Occupational Safety and Health, U.S. , Tamanho da Partícula , Estados Unidos , Local de TrabalhoRESUMO
Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with generally poor prognosis and no available targeted therapies, highlighting a critical unmet need to identify and characterize novel therapeutic targets. We previously demonstrated that CIB1 is necessary for cancer cell survival and proliferation via regulation of two oncogenic signaling pathways, RAF-MEK-ERK and PI3K-AKT. Because these pathways are often upregulated in TNBC, we hypothesized that CIB1 may play a broader role in TNBC cell survival and tumor growth. Methods utilized include inducible RNAi depletion of CIB1 in vitro and in vivo, immunoblotting, clonogenic assay, flow cytometry, RNA-sequencing, bioinformatics analysis, and Kaplan-Meier survival analysis. CIB1 depletion resulted in significant cell death in 8 of 11 TNBC cell lines tested. Analysis of components related to PI3K-AKT and RAF-MEK-ERK signaling revealed that elevated AKT activation status and low PTEN expression were key predictors of sensitivity to CIB1 depletion. Furthermore, CIB1 knockdown caused dramatic shrinkage of MDA-MB-468 xenograft tumors in vivo. RNA sequence analysis also showed that CIB1 depletion in TNBC cells activates gene programs associated with decreased proliferation and increased cell death. CIB1 expression levels per se did not predict TNBC susceptibility to CIB1 depletion, and CIB1 mRNA expression levels did not associate with TNBC patient survival. Our data are consistent with the emerging concept of non-oncogene addiction, where a large subset of TNBCs depend on CIB1 for cell survival and tumor growth, independent of CIB1 expression levels. Our data establish CIB1 as a novel therapeutic target for TNBC.
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Proteínas de Ligação ao Cálcio/genética , Sobrevivência Celular/genética , Neoplasias de Mama Triplo Negativas/genética , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Análise por Conglomerados , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Xenoenxertos , Humanos , Camundongos , Prognóstico , Interferência de RNA , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/mortalidade , Neoplasias de Mama Triplo Negativas/patologia , Carga Tumoral , Quinases Ativadas por p21/metabolismoRESUMO
BACKGROUND: the objective of the study was to estimate and compare the incidence rates of ischaemic and haemorrhagic stroke and seizure among cohorts with and without Alzheimer's disease (AD) dementia. METHODS: we conducted a retrospective cohort study using electronic medical records (EMRs) from primary care practices that participated in The Health Improvement Network (THIN) in the United Kingdom from 1 January 1990 to 31 July 2009. For each AD-dementia patient, we selected one general population control patient without AD-dementia matched to one AD-dementia patient on year of birth, sex and physician practice. FINDINGS: the AD-dementia cohorts were 68% female and averaged 80 years of age at the start of follow-up. Populations for analysis included 19,902 AD-dementia and matched non-AD-dementia patients with no history of stroke at baseline in which 790 incident cases of stroke occurred, and similarly, 22,084 AD-dementia and matched patients with no history of seizure at baseline in which 286 cases of seizure occurred. After adjusting for risk factors for each outcome, hazard ratios comparing AD-dementia with non-AD-dementia patients indicated higher rates among AD-dementia patients for stroke (HR = 1.29, 95% CI 1.11, 1.50) and seizure (HR = 5.31, 95% CI 3.97, 7.10). For stroke and seizure, the incidence rate ratios comparing AD-dementia patients with non-AD-dementia controls were greatest for the younger age groups. AD-dementia was observed to be a risk factor for both haemorrhagic stroke and seizures. Increasing age was associated with a decrease in relative risk and an increase in absolute risk.
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Doença de Alzheimer/complicações , Avaliação Geriátrica/métodos , Vigilância da População/métodos , Convulsões/epidemiologia , Acidente Vascular Cerebral/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Registros Eletrônicos de Saúde , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Convulsões/etiologia , Acidente Vascular Cerebral/etiologia , Reino Unido/epidemiologiaRESUMO
This study characterized potential inhalation exposures of workers to nanometal oxides associated with industrial wastewater treatment processes in a semiconductor research and development facility. Exposure assessment methodology was designed to capture aerosolized engineered nanomaterials associated with the chemical mechanical planarization wafer polishing process that were accessible for worker contact via inhalation in the on-site wastewater treatment facility. The research team conducted air sampling using a combination of filter-based capture methods for particle identification and characterization and real-time direct-reading instruments for semi-quantitation of particle number concentration. Filter-based samples were analyzed using electron microscopy and energy-dispersive x-ray spectroscopy while real-time particle counting data underwent statistical analysis. Sampling conducted over 14 months included 5 discrete sampling series events for 7 job tasks in coordination with on-site employees. The number of filter-based samples captured for analysis by electron microscopy was: 5 from personal breathing zone, 4 from task areas, and 3 from the background. Direct-reading instruments collected data for 5 sample collection periods in the task area and the background, and 2 extended background collection periods. Engineered nanomaterials of interest (Si, Al, Ce) were identified by electron microscopy in filter-based samples from all areas of collection, existing as agglomerates (>500 nm) and nanoparticles (100 nm-500 nm). Particle counts showed an increase in number concentration during and after selected tasks above background. While additional data is needed to support further statistical analysis and determine trends, this initial investigation suggests that nanoparticles used or generated by chemical mechanical planarization become aerosolized and may be accessible for inhalation exposures by workers in wastewater treatment facilities. Additional research is needed to further quantify the level of exposure and determine the potential human health impacts.
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Poluentes Ocupacionais do Ar/análise , Nanoestruturas/análise , Exposição Ocupacional/análise , Semicondutores , Monitoramento Ambiental/métodos , Humanos , Exposição por Inalação/análise , Nanopartículas Metálicas/análise , Nanopartículas Metálicas/química , Nanoestruturas/química , Óxidos/análise , Óxidos/química , Material Particulado/análise , Eliminação de Resíduos Líquidos/métodos , Águas ResiduáriasRESUMO
BACKGROUND: Procarbazine is an anticancer agent that also inhibits monoamine oxidase, an enzyme responsible for the metabolism of various catecholamines, including serotonin. METHODS: A retrospective chart review of lymphoma patients who were treated with both procarbazine and an antidepressant, as well as procarbazine alone, was performed to determine if signs and symptoms of serotonin toxicity were present. RESULTS: A total of 65 patients received procarbazine between 2004 and 2010 and were eligible to be included in the study. Twenty-six of these patients received an antidepressant in combination with procarbazine, with selective serotonin reuptake inhibitors being the most common type of antidepressant. No patients in the study were diagnosed with serotonin toxicity, nor did any meet Hunter's diagnostic criteria for serotonin toxicity. Diarrhea, tremor, and shivering were the symptoms from Sternbach's criteria that were further analyzed, with diarrhea occurring 8.54% of the time, tremor occurring 5.53% of the time, and shivering occurring 2.51% of the time in patients who received an antidepressant with their procarbazine. Despite these symptoms, the diagnosis of serotonin toxicity according to Sternbach's criteria was determined to be unlikely. CONCLUSIONS: In this small sample of patients treated with procarbazine plus an antidepressant (most typically SSRIs), there were no reports of serotonin toxicity, nor did any patients demonstrate symptoms consistent with serotonin toxicity. The authors urge clinicians to ensure depression is adequately managed in cancer patients who are undergoing procarbazine therapy, starting with typical first-line antidepressant agents.
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Antidepressivos/uso terapêutico , Antineoplásicos/efeitos adversos , Procarbazina/efeitos adversos , Serotonina/toxicidade , Antidepressivos/efeitos adversos , Antineoplásicos/uso terapêutico , Interações Medicamentosas , Feminino , Humanos , Linfoma/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Procarbazina/uso terapêutico , Estudos Retrospectivos , Inibidores Seletivos de Recaptação de Serotonina/efeitos adversos , Inibidores Seletivos de Recaptação de Serotonina/uso terapêuticoRESUMO
A benefit-risk assessment of NVX-CoV2373, a vaccine to prevent COVID-19, was conducted to determine if the benefits of vaccination outweigh the risks of myocarditis/pericarditis. This analysis used data on myocarditis/pericarditis cases observed in the NVX-CoV2373 clinical studies, real-world data of mRNA COVID vaccine effectiveness against predominant SARS-CoV-2 strains in early 2023, and recent COVID-19 burden of disease data from the United States. The benefits of NVX-CoV2373 vaccination were estimated as the number of COVID-19 cases, hospitalizations, and deaths prevented. The risks of myocarditis/pericarditis cases and related hospitalizations and deaths occurring within 7 days of vaccination were also estimated. In our analysis, vaccination with NVX-CoV2373, per 100,000 vaccinated, resulted in an estimated 1805 COVID-19 cases prevented compared with an estimated 5.3 excess myocarditis/pericarditis cases. The number of COVID-19 hospitalizations and deaths prevented were also greater than vaccine-associated myocarditis/pericarditis hospitalizations and deaths. Our analysis indicates a positive benefit-risk balance for NVX-CoV2373.
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COVID-19 , Miocardite , Pericardite , Humanos , Vacinas contra COVID-19/efeitos adversos , COVID-19/prevenção & controle , SARS-CoV-2 , Vacinação , Vacinas de mRNA , Medição de RiscoRESUMO
Myogenic differentiation is integral for the regeneration of skeletal muscle following tissue damage. Though high-energy post-mitotic muscle relies predominantly on mitochondrial respiration, the importance of mitochondrial remodeling in enabling muscle differentiation and the players involved are not fully known. Here we show that the mitochondrial fusion protein OPA1 is essential for muscle differentiation. Our study demonstrates that OPA1 loss or inhibition, through genetic and pharmacological means, abolishes in vivo muscle regeneration and in vitro myotube formation. We show that both the inhibition and genetic deletion of OPA1 prevent the early onset metabolic switch required to drive myoblast differentiation. In addition, we observe an OPA1-dependent upregulation of the supercomplex assembly factor, SCAF1, at the onset of differentiation. Importantly, preventing the upregulation of SCAF1, through OPA1 loss or siRNA-mediated SCAF1 knockdown, impairs metabolic reprogramming and muscle differentiation. These findings reveal the integral role of OPA1 and mitochondrial reprogramming at the onset of myogenic differentiation.
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Vaccine Benefit-Risk (B-R) assessment consists of evaluating the benefits and risks of a vaccine and making a judgment whether the expected key benefits outweigh the potential key risks associated with its expected use. B-R supports regulatory and public health decision-making throughout the vaccine's lifecycle. In August 2021, the Brighton Collaboration's Benefit-Risk Assessment of VAccines by TechnolOgy (BRAVATO) Benefit-Risk Assessment Module working group was established to develop a standard module to support the planning, conduct and evaluation of structured B-R assessments for vaccines from different platforms, based on data from clinical trials, post-marketing studies and real-world evidence. It enables sharing of relevant information via value trees, effects tables and graphical depictions of B-R trade-offs. It is intended to support vaccine developers, funders, regulators and policy makers in high-, middle- or low-income countries to help inform decision-making and facilitate transparent communication concerning development, licensure, deployment and other lifecycle decisions.
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Vacinas , Medição de Risco , Vacinas/efeitos adversos , HumanosRESUMO
The DNA gyrase negative supercoiling mechanism involves the assembly of a large gyrase/DNA complex and conformational rearrangements coupled to ATP hydrolysis. To establish the complex arrangement that directs the reaction towards negative supercoiling, bacterial gyrase complexes bound to 137- or 217-bp DNA fragments representing the starting conformational state of the catalytic cycle were characterized by sedimentation velocity and small-angle X-ray scattering (SAXS) experiments. The experiments revealed elongated complexes with hydrodynamic radii of 70-80 Å. Molecular envelopes calculated from these SAXS data show 2-fold symmetric molecules with the C-terminal domain (CTD) of the A subunit and the ATPase domain of the B subunit at opposite ends of the complexes. The proposed gyrase model, with the DNA binding along the sides of the molecule and wrapping around the CTDs located near the exit gate of the protein, adds new information on the mechanism of DNA negative supercoiling.
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DNA Girase/química , DNA/química , Biocatálise , Modelos Moleculares , Conformação de Ácido Nucleico , Espalhamento a Baixo Ângulo , Difração de Raios XRESUMO
Since changes in mitochondrial morphology regulate key functions of stem cells, it is important to assess their structure under physiological and pathophysiological conditions. Here, we present techniques optimized in rare adult muscle stem cells (MuSCs). For evaluating mitochondrial length and volume within a compact cytoplasmic area in MuSCs on intact myofibers, we describe steps for mitochondrial staining, imaging, and quantification. For evaluating mitochondrial ultrastructure in small cell numbers, we describe steps for agarose embedding and quantification by TEM. For complete details on generation and use of this protocol, please refer to Baker et al. (2022).1.
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Células-Tronco Adultas , Mitocôndrias , Animais , Camundongos , Membranas Mitocondriais , Citoplasma , Células-TroncoRESUMO
The American Academy of Pediatrics recommends premedication for all nonemergent neonatal intubations, yet there remains significant variation in this practice nationally. We aimed to standardize our unit's premedication practices for improved intubation success and reduced adverse events. Methods: The study workgroup developed educational material and protocol content. Process measures included premedication use, education, and audit form completion. Primary (success on first intubation attempt and adverse event rates) and secondary (trainee success) study outcomes are displayed using statistical process control charts and pre-post cohort comparisons. Results: Forty-seven percent (97/206) of nurses completed educational intervention before protocol release, with an additional 20% (42/206) following a staff reminder. Two hundred sixteen (216) patients were intubated per protocol with 81% (174/216) audit completion. Compared with baseline (n = 158), intubation attempts decreased from 2 (IQR, 1-2) to 1 (IQR, 1-2) (P = 0.03), and success on the first attempt increased from 40% (63/158) to 57% (124/216) (P < 0.01), with a notable improvement in trainee success from less than 1% (1/40) to 43% (31/72) (P < 0.01). The rate of severe and rare adverse events remained stable; however, there was a rise in nonsevere events from 30% (48/158) to 45% (98/216). The tachycardia rate increased with atropine use. There was no change in chest wall rigidity, number of infants unable to extubate following surfactant, or decompensation awaiting medications. Conclusions: Standardizing procedural care delivery reduced intubation attempts and increased the attempt success rate. However, this was accompanied by an increase in the rate of nonsevere adverse events.
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B cell survival has a central role in maintaining immune responses to foreign organisms while curbing autoimmunity. In this study, we show that mature B cell survival is impaired and B cell turnover is accelerated in the spleen of mice lacking secreted IgM. Although in vitro responses to BCR cross-linking were normal, there was a marked reduction in basal ERK and global tyrosine phosphorylation in splenic B cells from serum IgM-deficient mice, suggesting diminished interaction with cognate Ag in vivo. The provision of BAFF either in vitro or in vivo reversed the increase in B cell apoptosis, demonstrating that other survival signals can compensate for the loss of secreted IgM in the spleen. In striking contrast to the splenic compartment, peritoneal B cell survival was enhanced in secreted IgM-deficient mice, despite a similar reduction in basal BCR signaling compared with wild type mice. These results suggest that secreted IgM acts as an adjuvant, boosting BCR signals to maintain survival and maintenance of mature splenic B cells while increasing B cell apoptosis in the peritoneum. BAFF administration mitigated the consequences of secreted IgM deficiency on B cell survival in the spleen but not in the peritoneum. This work provides new insight into the regulation of B cell signaling and homeostasis in different peripheral compartments by secreted IgM.
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Linfócitos B/imunologia , Imunoglobulina M/imunologia , Peritônio/imunologia , Receptores de Antígenos de Linfócitos B/imunologia , Transdução de Sinais/imunologia , Baço/imunologia , Animais , Fator Ativador de Células B , Linfócitos B/citologia , Separação Celular , Sobrevivência Celular , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Immunoblotting , Imunoglobulina M/deficiência , Camundongos , Camundongos Transgênicos , Peritônio/citologia , Baço/citologiaRESUMO
In collaboration with RTI International, the U.S. National Institute for Occupational Safety and Health (NIOSH) administered a survey to North American companies working with nanomaterials to assess health and safety practices. The results would contribute to understanding the impact of the efforts made by the NIOSH Nanotechnology Research Center (NTRC) in communicating occupational health and safety (OHS) considerations for workers when handling these materials. The survey, developed by RAND Corporation, was conducted online from September 2019-December 2019. Forty-five companies or organizations in the U.S. and Canada that fabricate, manufacture, handle, dispose, or otherwise use nanomaterials completed the survey. The survey was designed to answer research questions regarding the nanomaterials in use, which resources the companies have consulted for OHS guidance, and the overall OHS culture at the companies. Other questions specifically addressed whether the companies interacted with NIOSH or NIOSH resources to inform OHS policies and practices. Among participating companies, 57.8% had a maximum of 50 employees. Gold nanoparticles and polymers were most common (n = 20; 45.5% each), followed by graphene (36.4%), carbon nanotubes and nanofibers (34.1%), and zinc oxide nanoparticles (31.8%). Environmental monitoring was performed by 31.8% of the companies. While 88.9% of the companies had laminar flow cabinets, only 67.5% required it to be used with ENMs. Information and training programs were indicated by 90% of the sample, and only 29.6% performed specific health surveillance for ENM workers. Personal protective equipment primarily included gloves (100%) and eye/face protection (97.7%). More than a third (37.8%) of the respondents reported using at least one NIOSH resource to acquire information about safe handling of ENMs. The small number of companies that responded to and completed the survey is a considerable limitation to this study. However, the survey data are valuable for gauging the reach and influence of the NIOSH NTRC on nano OHS and for informing future outreach, particularly to small businesses.
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Nanopartículas Metálicas , Nanoestruturas , Nanotubos de Carbono , Exposição Ocupacional , Saúde Ocupacional , Ouro , Humanos , Exposição Ocupacional/análise , Exposição Ocupacional/prevenção & controle , Inquéritos e Questionários , Estados UnidosRESUMO
Quiescence regulation is essential for adult stem cell maintenance and sustained regeneration. Our studies uncovered that physiological changes in mitochondrial shape regulate the quiescent state of adult muscle stem cells (MuSCs). We show that MuSC mitochondria rapidly fragment upon an activation stimulus, via systemic HGF/mTOR, to drive the exit from deep quiescence. Deletion of the mitochondrial fusion protein OPA1 and mitochondrial fragmentation transitions MuSCs into G-alert quiescence, causing premature activation and depletion upon a stimulus. OPA1 loss activates a glutathione (GSH)-redox signaling pathway promoting cell-cycle progression, myogenic gene expression, and commitment. MuSCs with chronic OPA1 loss, leading to mitochondrial dysfunction, continue to reside in G-alert but acquire severe cell-cycle defects. Additionally, we provide evidence that OPA1 decline and impaired mitochondrial dynamics contribute to age-related MuSC dysfunction. These findings reveal a fundamental role for OPA1 and mitochondrial dynamics in establishing the quiescent state and activation potential of adult stem cells.