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Resumen: Introducción: La neumonía grave por SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) ocasiona hipoxemia severa, por lo anterior, las guías para el manejo de pacientes adultos críticamente enfermos con COVID-19 recomiendan el uso de la posición decúbito prono para mejorar la oxigenación. Material y métodos: Estudio de cohorte, prospectivo, descriptivo y analítico. Pacientes ingresados a la unidad de cuidados intensivos en el periodo comprendido entre el 18 de abril de 2020 y el 18 de agosto de 2021 con ventilación mecánica invasiva (VMI) secundaria a neumonía grave por SARS-CoV-2 confirmados. Resultados: En el periodo comprendido se incluyeron 110 pacientes que cumplieron con los criterios de inclusión. Del total, 88 pacientes se incluyeron en el grupo de mejoría sostenida al retiro del prono y 22 en el grupo de mejoría no sostenida al retiro del prono. Se observó que la disminución del porcentaje de la PaO2/FiO2 al retiro del prono es útil para predecir mortalidad con ABC de 0.740 con IC95% de (0.646-0.834) y p = 0.001. Conclusión: La disminución > 50% de la PaO2/FiO2 al retiro de la posición decúbito prono prolongado o mejoría no sostenida es un predictor de mortalidad en los pacientes con neumonía grave por SARS-CoV-2.
Abstract: Introduction: Severe pneumonia due to SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) causes severe hypoxemia, therefore, the guidelines for the management of critically ill adult patients with COVID-19 recommend the use of the prone position to improve oxygenation. Material and methods: A prospective, descriptive and analytical cohort study. Patients admitted to the intensive care unit in the period from April 18, 2020 to August 18, 2021 with confirmed IMV secondary to severe SARS-CoV-2 pneumonia. Results: In the period covered, 110 patients who met the inclusion criteria were included. Of the total, 88 patients were included in the group with sustained improvement at prone withdrawal and 22 in the group with non-sustained improvement at prone withdrawal. It was observed that the% Decrease in PaO2/FiO2 upon prone removal is useful to predict mortality with AUC of 0.740 with 95% CI of (0.646-0.834) and p = 0.001. Conclusion: A > 50% decrease in PaO2/FiO2 upon removal from prolonged prone position or unsustained improvement is a predictor of mortality in patients with severe SARS-CoV-2 pneumonia.
Resumo: Introdução: A pneumonia grave por SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) causa hipoxemia grave, portanto, as diretrizes para o manejo de pacientes adultos criticamente doentes com COVID-19 recomendam o uso da posição prona para melhorar a oxigenação. Material e métodos: Estudo de coorte, prospectivo, descritivo e analítico. Pacientes admitidos na unidade de terapia intensiva no período entre 18 de abril de 2020 e 18 de agosto de 2021 com VMI secundária a pneumonia grave por SARS-CoV-2 confirmadas. Resultados: No período abrangido, incluíram-se 110 pacientes que atenderam aos critérios de inclusão. Do total, 88 pacientes foram incluídos no grupo melhora sustentada na retirada da posição prona e 22 no grupo melhora não sustentada na retirada da posição prona. Observou-se que a % de diminuição da PaO2/FiO2 na retirada da pronação é útil para predizer mortalidade com ABC de 0.740 com IC de 95% de (0.646-0.834) e p = 0.001. Conclusão: Uma diminuição > 50% na PaO2/FiO2 após a retirada da posição prona prolongada ou melhora não sustentada é um preditor de mortalidade em pacientes com pneumonia grave por SARS-CoV-2.
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Mitogenic signals that regulate cell division often proceed through multienzyme assemblies within defined intracellular compartments. The anchoring protein Gravin restricts the action of mitotic kinases and cell-cycle effectors to defined mitotic structures. In this report we discover that genetic deletion of Gravin disrupts proper accumulation and asymmetric distribution of γ-tubulin during mitosis. We utilize a new precision pharmacology tool, Local Kinase Inhibition, to inhibit the Gravin binding partner polo-like kinase 1 at spindle poles. Using a combination of gene-editing approaches, quantitative imaging, and biochemical assays, we provide evidence that disruption of local polo-like kinase 1 signaling underlies the γ-tubulin distribution defects observed with Gravin loss. Our study uncovers a new role for Gravin in coordinating γ-tubulin recruitment during mitosis and illuminates the mechanism by which signaling enzymes regulate this process at a distinct subcellular location.
Assuntos
Proteínas de Ancoragem à Quinase A/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais , Fuso Acromático/metabolismo , Tubulina (Proteína)/metabolismo , Proteínas de Ancoragem à Quinase A/genética , Proteínas de Ciclo Celular/genética , Células HEK293 , Células HeLa , Humanos , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Fuso Acromático/genética , Tubulina (Proteína)/genética , Quinase 1 Polo-LikeRESUMO
Deciphering how signaling enzymes operate within discrete microenvironments is fundamental to understanding biological processes. A-kinase anchoring proteins (AKAPs) restrict the range of action of protein kinases within intracellular compartments. We exploited the AKAP targeting concept to create genetically encoded platforms that restrain kinase inhibitor drugs at distinct subcellular locations. Local Kinase Inhibition (LoKI) allows us to ascribe organelle-specific functions to broad specificity kinases. Using chemical genetics, super resolution microscopy, and live-cell imaging we discover that centrosomal delivery of Polo-like kinase 1 (Plk1) and Aurora A (AurA) inhibitors attenuates kinase activity, produces spindle defects, and prolongs mitosis. Targeted inhibition of Plk1 in zebrafish embryos illustrates how centrosomal Plk1 underlies mitotic spindle assembly. Inhibition of kinetochore-associated pools of AurA blocks phosphorylation of microtubule-kinetochore components. This versatile precision pharmacology tool enhances investigation of local kinase biology.
Assuntos
Proteínas de Ancoragem à Quinase A/genética , Aurora Quinase A/genética , Proteínas de Ciclo Celular/genética , Mitose/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Animais , Aurora Quinase A/química , Proteínas de Ciclo Celular/química , Centrossomo/química , Centrossomo/ultraestrutura , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Cinetocoros/química , Microtúbulos/genética , Fosforilação/genética , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/química , Proteínas Proto-Oncogênicas/química , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento , Quinase 1 Polo-LikeRESUMO
Fibrolamellar carcinoma (FLC) is a rare liver cancer. FLCs uniquely produce DNAJ-PKAc, a chimeric enzyme consisting of a chaperonin-binding domain fused to the Cα subunit of protein kinase A. Biochemical analyses of clinical samples reveal that a unique property of this fusion enzyme is the ability to recruit heat shock protein 70 (Hsp70). This cellular chaperonin is frequently up-regulated in cancers. Gene-editing of mouse hepatocytes generated disease-relevant AML12DNAJ-PKAc cell lines. Further analyses indicate that the proto-oncogene A-kinase anchoring protein-Lbc is up-regulated in FLC and functions to cluster DNAJ-PKAc/Hsp70 sub-complexes with a RAF-MEK-ERK kinase module. Drug screening reveals Hsp70 and MEK inhibitor combinations that selectively block proliferation of AML12DNAJ-PKAc cells. Phosphoproteomic profiling demonstrates that DNAJ-PKAc biases the signaling landscape toward ERK activation and engages downstream kinase cascades. Thus, the oncogenic action of DNAJ-PKAc involves an acquired scaffolding function that permits recruitment of Hsp70 and mobilization of local ERK signaling.
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Carcinoma Hepatocelular/fisiopatologia , Subunidades Catalíticas da Proteína Quinase Dependente de AMP Cíclico/metabolismo , Proteínas Fetais/metabolismo , Neoplasias Hepáticas/fisiopatologia , Chaperonas Moleculares/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Proteínas de Ancoragem à Quinase A/metabolismo , Animais , Linhagem Celular , Proliferação de Células , Subunidades Catalíticas da Proteína Quinase Dependente de AMP Cíclico/genética , Proteínas Fetais/genética , Proteínas de Choque Térmico HSP70/metabolismo , Hepatócitos/patologia , Humanos , Camundongos , Modelos Teóricos , Chaperonas Moleculares/genética , Ligação Proteica , Proto-Oncogene Mas , Proteínas Recombinantes de Fusão/genética , Transdução de SinaisRESUMO
The diffusion and distribution coefficients are important parameters in the design of barrier systems used in radioactive repositories. These coefficients can be determined using a two-reservoir configuration, where a saturated porous medium is allocated between two reservoirs filled by stagnant water. One of the reservoirs contains a high concentration of radioisotopes. The goal of this work is to obtain an analytical solution for the concentration of all radioisotopes in the decay chain of a two-reservoir configuration. The analytical solution must be obtained by taking into account the diffusion and sorption processes. Concepts such as overvalued concentration, diffusion and decay factors are employed to this end. It is analytically proven that a factor of the solution is identical for all chains (considering a time scaling factor), if certain parameters do not change. In addition, it is proven that the concentration sensitivity, due to the distribution coefficient variation, depends of the porous medium thickness, which is practically insensitive for small porous medium thicknesses. The analytical solution for the radioisotope concentration is compared with experimental and numerical results available in literature.
