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The AKT-mTOR pathway is a central regulator of cell growth and metabolism. Upon sustained mTOR activity, AKT activity is attenuated by a feedback loop that restrains upstream signaling. However, how cells control the signals that limit AKT activity is not fully understood. Here, we show that MASTL/Greatwall, a cell cycle kinase that supports mitosis by phosphorylating the PP2A/B55 inhibitors ENSA/ARPP19, inhibits PI3K-AKT activity by sustaining mTORC1- and S6K1-dependent phosphorylation of IRS1 and GRB10. Genetic depletion of MASTL results in an inefficient feedback loop and AKT hyperactivity. These defects are rescued by the expression of phosphomimetic ENSA/ARPP19 or inhibition of PP2A/B55 phosphatases. MASTL is directly phosphorylated by mTORC1, thereby limiting the PP2A/B55-dependent dephosphorylation of IRS1 and GRB10 downstream of mTORC1. Downregulation of MASTL results in increased glucose uptake in vitro and increased glucose tolerance in adult mice, suggesting the relevance of the MASTL-PP2A/B55 kinase-phosphatase module in controlling AKT and maintaining metabolic homeostasis.
Assuntos
Alvo Mecanístico do Complexo 1 de Rapamicina , Proteína Fosfatase 2 , Proteínas Serina-Treonina Quinases , Animais , Camundongos , Ciclo Celular/genética , Glucose/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Mitose , Fosfatidilinositol 3-Quinases/genética , Fosforilação , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismoRESUMO
Influenza virus RNA polymerase (FluPol), a heterotrimer composed of PB1, PB2, and PA subunits (P3 in influenza C), performs both transcription and replication of the viral RNA genome. For transcription, FluPol interacts with the C-terminal domain (CTD) of RNA polymerase II (Pol II), which enables FluPol to snatch capped RNA primers from nascent host RNAs. Here, we describe the co-crystal structure of influenza C virus polymerase (FluPolC) bound to a Ser5-phosphorylated CTD (pS5-CTD) peptide. The position of the CTD-binding site at the interface of PB1, P3, and the flexible PB2 C-terminal domains suggests that CTD binding stabilizes the transcription-competent conformation of FluPol. In agreement, both cap snatching and capped primer-dependent transcription initiation by FluPolC are enhanced in the presence of pS5-CTD. Mutations of amino acids in the CTD-binding site reduce viral mRNA synthesis. We propose a model for the activation of the influenza virus transcriptase through its association with pS5-CTD of Pol II.
Assuntos
RNA Polimerases Dirigidas por DNA/genética , Gammainfluenzavirus/genética , Gammainfluenzavirus/ultraestrutura , RNA Polimerases Dirigidas por DNA/fisiologia , Humanos , Ligação Proteica , Domínios Proteicos/fisiologia , Capuzes de RNA/genética , RNA Polimerase II/metabolismo , RNA Polimerase II/fisiologia , RNA Viral/metabolismo , RNA Polimerase Dependente de RNA/genética , Transcrição Gênica , Proteínas Virais/genética , Replicação ViralRESUMO
Two novel cyclometallated iridium(III) complexes have been prepared with one bidentate or two monodentate imidazole-based ligands, 1 and 2, respectively. The complexes showed intense emission with long lifetimes of the excited state. Femtosecond transient absorption experiments established the nature of the lowest excited state as 3IL state. Singlet oxygen generation with good yields (40% for 1 and 82% for 2) was established by detecting 1O2 directly, through its emission at 1270 nm. Photostability studies were also performed to assess the viability of the complexes as photosensitizers (PS) for photodynamic therapy (PDT). Complex 1 was selected as a good candidate to investigate light-activated killing of cells, whilst complex 2 was found to be toxic in the dark and unstable under light. Complex 1 demonstrated high phototoxicity indexes (PI) in the visible region, PI > 250 after irradiation at 405 nm and PI > 150 at 455 nm, in EJ bladder cancer cells.
Assuntos
Benzimidazóis , Neoplasias , Fotoquimioterapia , Ligantes , Linhagem Celular Tumoral , Fármacos Fotossensibilizantes/química , Morte Celular , Irídio/farmacologia , Irídio/químicaRESUMO
Salinity and excess zinc are two main problems that have limited agriculture in recent years. Aquaporins are crucial in regulating the passage of water and solutes through cells and may be essential for mitigating abiotic stresses. In the present study, the adaptive response to moderate salinity (60 mM NaCl) and excess Zn (1 mM ZnSO4 ) were compared alone and in combination in Cucumis sativus L. and Solanum lycopersicum L. Water relations, gas exchange and the differential expression of all aquaporins were analysed. The results showed that cucumber plants under salinity maintained the internal movement of water through osmotic adjustment and the overexpression of specific PIPs aquaporins, following a "conservation strategy". As tomato has a high tolerance to salinity, the physiological parameters and the expression of most aquaporins remained unchanged. ZnSO4 was shown to be stressful for both plant species. While cucumber upregulated 7 aquaporin isoforms, the expression of aquaporins increased in a generalized manner in tomato. Despite the differences, water relations and transpiration were adjusted in both plants, allowing the RWC in the shoot to be maintained. The aquaporin regulation in cucumber plants facing NaCl+ZnSO4 stress was similar in the two treatments containing NaCl, evidencing the predominance of salt in stress. However, in tomato, the induced expression of specific isoforms to deal with the combined stress differed from independent stresses. The results clarify the key role of aquaporin regulation in facing abiotic stresses and their possible use as markers of tolerance to salinity and heavy metals in plants.
Assuntos
Aquaporinas , Cucumis sativus , Solanum lycopersicum , Aquaporinas/genética , Aquaporinas/metabolismo , Cucumis sativus/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Isoformas de Proteínas/metabolismo , Salinidade , Cloreto de Sódio/farmacologia , Cloreto de Sódio/metabolismo , Solanum lycopersicum/genética , Estresse Fisiológico , Água/metabolismo , Zinco/metabolismo , Sulfato de Zinco/química , Sulfato de Zinco/metabolismoRESUMO
A novel Ru(II) cyclometalated photosensitizer (PS), Ru-NH2 , for photodynamic therapy (PDT) of formula [Ru(appy)(bphen)2 ]PF6 (where appy=4-amino-2-phenylpyridine and bphen=bathophenanthroline) and its cetuximab (CTX) bioconjugates, Ru-Mal-CTX and Ru-BAA-CTX (where Mal=maleimide and BAA=benzoylacrylic acid) were synthesised and characterised. The photophysical properties of Ru-NH2 revealed absorption maxima around 580â nm with an absorption up to 725â nm. The generation of singlet oxygen (1 O2 ) upon light irradiation was confirmed with a 1 O2 quantum yield of 0.19 in acetonitrile. Preliminary inâ vitro experiments revealed the Ru-NH2 was nontoxic in the dark in CT-26 and SQ20B cell lines but showed outstanding phototoxicity when irradiated, reaching interesting phototoxicity indexes (PI) >370 at 670â nm, and >150 at 740â nm for CT-26 cells and >50 with NIR light in SQ20B cells. The antibody CTX was successfully attached to the complexes in view of the selective delivery of the PS to cancer cells. Up to four ruthenium fragments were anchored to the antibody (Ab), as confirmed by MALDI-TOF mass spectrometry. Nonetheless, the bioconjugates were not as photoactive as the Ru-NH2 complex.
Assuntos
Complexos de Coordenação , Fotoquimioterapia , Rutênio , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Cetuximab/farmacologia , Rutênio/química , Complexos de Coordenação/químicaRESUMO
Transient cerebral ischemia induces neuronal degeneration, followed in time by secondary delayed neuronal death that is strongly correlated with a permanent inhibition of protein synthesis in vulnerable brain regions, while protein translational rates are recovered in resistant areas. In the translation-regulation initiation step, the eukaryotic initiation factor (eIF) 4E is a key player regulated by its association with eIF4E-binding proteins (4E-BPs), mostly 4E-BP2 in brain tissue. In a previous work, we identified dihydropyrimidinase-related protein 2 (DRP2) as a 4E-BP2-interacting protein. Here, using a proteomic approach in a model of transient cerebral ischemia, a detailed study of DRP2 was performed in order to address the challenge of translation restoration in vulnerable regions. In this report, several DRP2 isoforms that have a specific interaction with both 4E-BP2 and eIF4E were identified, showing significant and opposite differences in this association, and being differentially detected in resistant and vulnerable regions in response to ischemia reperfusion. Our results provide the first evidence of DRP2 isoforms as potential regulators of the 4E-BP2-eIF4E association that would have consequences in the delayed neuronal death under ischemic-reperfusion stress. The new knowledge reported here identifies DRP2 as a new target to promote neuronal survival after cerebral ischemia.
Assuntos
Isquemia Encefálica , Ataque Isquêmico Transitório , Isquemia Encefálica/metabolismo , Infarto Cerebral , Fator de Iniciação 4E em Eucariotos/genética , Fatores de Iniciação em Eucariotos/metabolismo , Fosfoproteínas/metabolismo , Fosforilação , Ligação Proteica , Biossíntese de Proteínas , Isoformas de Proteínas/metabolismo , Proteômica , Animais , RatosRESUMO
Agricultural washing wastewater (AWW) is an important source of pesticides that, given its intrinsic characteristics, has a high potential to be treated by fungal bioremediation using white rot fungi. In the present study, two AWW treatment strategies were compared: a fluidized-bed reactor (FBR) with T. versicolor pellets and a rotating drum bioreactor (RDB) with T. versicolor immobilized on wood. The RDB effluent showed better results in all studied parameters compared to those of the FBR, including pesticide removal (87%), toxicity, laccase activity, COD, absorbance and microbial communities. Additionally, the fungal assemblage showed that T. versicolor was successfully immobilized in the RDB, which triggered a major shift in the initial community. Afterwards, solid by-products were treated in a fungal biopile-like system reaching high biodegradation rates. Therefore, this study validates the fungal RDB as a viable alternative for AWW treatment, opening up the possibility of a further in-situ and full-scale application.
Assuntos
Praguicidas , Águas Residuárias , Agricultura , Reatores Biológicos , Biodegradação AmbientalRESUMO
Proper progression throughout the cell division cycle depends on the expression level of a family of proteins known as cyclins, and the subsequent activation of cyclin-dependent kinases (Cdks). Among the numerous members of the mammalian cyclin family, only a few of them, cyclins A, B, C, D and E, are known to display critical roles in the cell cycle. These functions will be reviewed here with a special focus on their relevance in different cell types in vivo and their implications in human disease.
Assuntos
Ciclo Celular , Ciclinas/metabolismo , Mamíferos/metabolismo , Animais , Ciclo Celular/genética , Segregação de Cromossomos/genética , Replicação do DNA/genética , Humanos , Transcrição GênicaRESUMO
The effect of elastic strains on the catalytic activity for the hydrogen evolution reaction (HER) and the oxygen reduction reaction (ORR) was analyzed on thirteen late transition metals: eight (111) surfaces of fcc metals (Ni, Cu, Pd, Ag, Pt, Au, Rh, Ir) and five (0001) surfaces of hcp metals (Co, Zn, Cd, Ru, and Os). The corresponding adsorption energies for the different intermediate reactions up to strains dictated by the mechanical stability limits were previously obtained by means of density functional theory calculations. It was found that the elastic strains can be used to tune the catalytic activity of different metals by reducing the energy barrier of the rate limiting step and even to reach the cusp of the volcano plot. The largest changes in catalytic activity with strain for the HER were found in Pt, Au, and Ir while Co and Ni were very insensitive to this strategy. In the case of the ORR, the catalytic activity of Au could be enhanced by the application of tensile strains while that of Cu, Ni, Pt, Pd, Rh, Co, Ru, and Os was improved by the application of compressive strains. However, the catalytic activity of Ir was rather insensitive to mechanical deformations. Elastic strains were able to modify the rate limiting reaction in Au, Pt, Ag, and Os and it was possible to achieve the cusp of the volcano plot in these metals. Final, mechanical instabilities were attained at small strains in Zn and Cd, which did not lead to significant changes in the catalytic activity for the HER and the ORR. These results provide a framework to systematically investigate the application of elastic strains in the design of new catalysts.
RESUMO
Ischemic strokes are caused by a reduction in cerebral blood flow and both the ischemic period and subsequent reperfusion induce brain injury, with different tissue damage depending on the severity of the ischemic insult, its duration, and the particular areas of the brain affected. In those areas vulnerable to cerebral ischemia, the inhibition of protein translation is an essential process of the cellular response leading to delayed neuronal death. In particular, translation initiation is rate-limiting for protein synthesis and the eukaryotic initiation factor (eIF) 4F complex is indispensable for cap-dependent protein translation. In the eIF4F complex, eIF4G is a scaffolding protein that provides docking sites for the assembly of eIF4A and eIF4E, binding to the cap structure of the mRNA and stabilizing all proteins of the complex. The eIF4F complex constituents, eIF4A, eIF4E, and eIF4G, participate in translation regulation by their phosphorylation at specific sites under cellular stress conditions, modulating the activity of the cap-binding complex and protein translation. This work investigates the phosphorylation of eIF4G1 involved in the eIF4E/eIF4G1 association complex, and their regulation in ischemia-reperfusion (IR) as a stress-inducing condition. IR was induced in an animal model of transient cerebral ischemia and the results were studied in the resistant cortical region and in the vulnerable hippocampal CA1 region. The presented data demonstrate the phosphorylation of eIF4G1 at Ser1147, Ser1185, and Ser1231 in both brain regions and in control and ischemic conditions, being the phosphorylation of eIF4G1 at Ser1147 the only one found in the eIF4E/eIF4G association complex from the cap-containing matrix (m7GTP-Sepharose). In addition, our work reveals the specific modulation of the phosphorylation of eIF4G1 at Ser1147 in the vulnerable region, with increased levels and colocalization with eIF4E in response to IR. These findings contribute to elucidate the molecular mechanism of protein translation regulation that underlies in the balance of cell survival/death during pathophysiological stress, such as cerebral ischemia.
Assuntos
Isquemia Encefálica/metabolismo , Fator de Iniciação 4E em Eucariotos/metabolismo , Fator de Iniciação Eucariótico 4G/metabolismo , Serina/metabolismo , Animais , Sítios de Ligação , Isquemia Encefálica/etiologia , Região CA1 Hipocampal/metabolismo , Modelos Animais de Doenças , Humanos , Masculino , Fosforilação , RatosRESUMO
Brain stroke is a highly prevalent pathology and a main cause of disability among older adults. If not promptly treated with recanalization therapies, primary and secondary mechanisms of injury contribute to an increase in the lesion, enhancing neurological deficits. Targeting excitotoxicity and oxidative stress are very promising approaches, but only a few compounds have reached the clinic with relatively good positive outcomes. The exploration of novel targets might overcome the lack of clinical translation of previous efficient preclinical neuroprotective treatments. In this study, we examined the neuroprotective properties of 2-aminoethoxydiphenyl borate (2-APB), a molecule that interferes with intracellular calcium dynamics by the antagonization of several channels and receptors. In a permanent model of cerebral ischemia, we showed that 2-APB reduces the extent of the damage and preserves the functionality of the cortical territory, as evaluated by somatosensory evoked potentials (SSEPs). While in this permanent ischemia model, the neuroprotective effect exerted by the antioxidant scavenger cholesteronitrone F2 was associated with a reduction in reactive oxygen species (ROS) and better neuronal survival in the penumbra, 2-APB did not modify the inflammatory response or decrease the content of ROS and was mostly associated with a shortening of peri-infarct depolarizations, which translated into better cerebral blood perfusion in the penumbra. Our study highlights the potential of 2-APB to target spreading depolarization events and their associated inverse hemodynamic changes, which mainly contribute to extension of the area of lesion in cerebrovascular pathologies.
Assuntos
Isquemia Encefálica , Depressão Alastrante da Atividade Elétrica Cortical , Idoso , Boratos/farmacologia , Isquemia Encefálica/patologia , Circulação Cerebrovascular/fisiologia , Humanos , Infarto , Neuroproteção , Espécies Reativas de OxigênioRESUMO
The influence of elastic strains on the adsorption of H, O, and OH on the (111) surfaces of 8 fcc (Ni, Cu, Pd, Ag, Pt, Au, Rh, Ir) and on the (0001) surfaces of 3 hcp (Co, Zn, Cd) transition metals was analyzed by means of density functional theory calculations. To this end, surface slabs were subjected to different strain states (uniaxial, biaxial, shear, and a combination of them) up to strains dictated by the mechanical stability limits indicated by phonon calculations. It was found that the adsorption energy followed the predictions of the d-band theory but - surprisingly - the variations in the adsorption energy only depended on the area of the adsorption hole and not on the particular elastic strain tensor applied to achieve this area. The analysis of the electronic structure showed that the applied strains did not modify the shape of the Projected Density of States (PDOS) of the d-orbitals of the transition metals but only led to a shift in the energy levels. Moreover, the presence of the adsorbates on the surfaces led to negligible changes in the PDOS. Thus, the adsorption energies were a function of the Fermi energy which in turn was associated with the change of the area of the adsorption through a general linear law that was valid for all metals. The information in this paper allows the immediate and accurate estimation of the effect of any elastic strain on the adsorption energies of H, O, and OH in 11 transition metals with more than half-filled d-orbitals.
RESUMO
Parkinson's disease (PD) is the second most frequent neurodegenerative disease. It is characterized by the loss of dopaminergic neurons in the substantia nigra and the formation of large aggregates in the survival neurons called Lewy bodies, which mainly contain α-synuclein (α-syn). The cause of cell death is not known but could be due to mitochondrial dysfunction, protein homeostasis failure, and alterations in the secretory/endolysosomal/autophagic pathways. Survival nigral neurons overexpress the small GTPase Rab1. This protein is considered a housekeeping Rab that is necessary to support the secretory pathway, the maintenance of the Golgi complex structure, and the regulation of macroautophagy from yeast to humans. It is also involved in signaling, carcinogenesis, and infection for some pathogens. It has been shown that it is directly linked to the pathogenesis of PD and other neurodegenerative diseases. It has a protective effect against α-σψν toxicity and has recently been shown to be a substrate of LRRK2, which is the most common cause of familial PD and the risk of sporadic disease. In this review, we analyze the key aspects of Rab1 function in dopamine neurons and its implications in PD neurodegeneration/restauration. The results of the current and former research support the notion that this GTPase is a good candidate for therapeutic strategies.
Assuntos
Doença de Parkinson/patologia , Proteínas rab1 de Ligação ao GTP/metabolismo , Animais , Humanos , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Proteínas rab1 de Ligação ao GTP/genéticaRESUMO
Cerebral ischemia induces an inhibition of protein synthesis and causes cell death and neuronal deficits. These deleterious effects do not occur in resilient areas of the brain, where protein synthesis is restored. In cellular stress conditions, as brain ischemia, translational repressors named eukaryotic initiation factor (eIF) 4E-binding proteins (4E-BPs) specifically bind to eIF4E and are critical in the translational control. We previously described that 4E-BP2 protein, highly expressed in brain, can be a molecular target for the control of cell death or survival in the reperfusion after ischemia in an animal model of transient cerebral ischemia. Since these previous studies showed that phosphorylation would not be the regulation that controls the binding of 4E-BP2 to eIF4E under ischemic stress, we decided to investigate the differential detection of 4E-BP2-interacting proteins in two brain regions with different vulnerability to ischemia-reperfusion (IR) in this animal model, to discover new potential 4E-BP2 modulators and biomarkers of cerebral ischemia. For this purpose, 4E-BP2 immunoprecipitates from the resistant cortical region and the vulnerable hippocampal cornu ammonis 1 (CA1) region were analyzed by two-dimensional (2-D) fluorescence difference in gel electrophoresis (DIGE), and after a biological variation analysis, 4E-BP2-interacting proteins were identified by matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry. Interestingly, among the 4E-BP2-interacting proteins identified, heat shock 70 kDa protein-8 (HSC70), dihydropyrimidinase-related protein-2 (DRP2), enolase-1, ubiquitin carboxyl-terminal hydrolase isozyme-L1 (UCHL1), adenylate kinase isoenzyme-1 (ADK1), nucleoside diphosphate kinase-A (NDKA), and Rho GDP-dissociation inhibitor-1 (Rho-GDI), were of notable interest, showing significant differences in their association with 4E-BP2 between resistant and vulnerable regions to ischemic stress. Our data contributes to the first characterization of the 4E-BP2 interactome, increasing the knowledge in the molecular basis of the protection and vulnerability of the ischemic regions and opens the way to detect new biomarkers and therapeutic targets for diagnosis and treatment of cerebral ischemia.
Assuntos
Isquemia Encefálica/metabolismo , Morte Celular/fisiologia , Fatores de Iniciação em Eucariotos/metabolismo , Neurônios/metabolismo , Traumatismo por Reperfusão/metabolismo , Animais , Isquemia Encefálica/patologia , Região CA1 Hipocampal/metabolismo , Região CA1 Hipocampal/patologia , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Masculino , Neurônios/patologia , Fosfoproteínas/metabolismo , Fosforilação/fisiologia , Ligação Proteica/fisiologia , Biossíntese de Proteínas/fisiologia , Ratos , Ratos Wistar , Traumatismo por Reperfusão/patologiaRESUMO
Our aim was to investigate the subset distribution and function of circulating monocytes, proinflammatory cytokine levels, gut barrier damage, and bacterial translocation in chronic spinal cord injury (SCI) patients. Thus, 56 SCI patients and 28 healthy donors were studied. The levels of circulating CD14+highCD16-, CD14+highCD16+, and CD14+lowCD16+ monocytes, membrane TLR2, TLR4, and TLR9, phagocytic activity, ROS generation, and intracytoplasmic TNF-α, IL-1, IL-6, and IL-10 after lipopolysaccharide (LPS) stimulation were analyzed by polychromatic flow cytometry. Serum TNF-α, IL-1, IL-6 and IL-10 levels were measured by Luminex and LPS-binding protein (LBP), intestinal fatty acid-binding protein (I-FABP) and zonulin by ELISA. SCI patients had normal monocyte counts and subset distribution. CD14+highCD16- and CD14+highCD16+ monocytes exhibited decreased TLR4, normal TLR2 and increased TLR9 expression. CD14+highCD16- monocytes had increased LPS-induced TNF-α but normal IL-1, IL-6, and IL-10 production. Monocytes exhibited defective phagocytosis but normal ROS production. Patients had enhanced serum TNF-α and IL-6 levels, normal IL-1 and IL-10 levels, and increased circulating LBP, I-FABP, and zonulin levels. Chronic SCI patients displayed impaired circulating monocyte function. These patients exhibited a systemic proinflammatory state characterized by enhanced serum TNF-α and IL-6 levels. These patients also had increased bacterial translocation and gut barrier damage.
Assuntos
Suscetibilidade a Doenças , Inflamação/complicações , Enteropatias/complicações , Traumatismos da Medula Espinal/etiologia , Traumatismos da Medula Espinal/metabolismo , Adulto , Biomarcadores , Estudos de Casos e Controles , Doença Crônica , Citocinas/metabolismo , Feminino , Homeostase , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Monócitos/imunologia , Monócitos/metabolismo , Fagócitos/imunologia , Fagócitos/metabolismo , Fagocitose , Índice de Gravidade de Doença , Traumatismos da Medula Espinal/patologia , Fator de Necrose Tumoral alfa/metabolismo , Adulto JovemRESUMO
The synthesis and characterization of two half-sandwich complexes of Ru(II) and Ir(III) with thiabendazole as ancillary ligand and their DNA binding ability were investigated using experimental and computational methods. 1H NMR and acid-base studies have shown that aquo-complexes are the reactive species. Kinetic studies show that both complexes bind covalently to DNA through the metal site and non covalently through the ancillary ligand. Thermal stability studies, viscosity, circular dichroism measurements and quantum chemical calculations have shown that the covalent binding causes breaking of the H-bonding between base pairs, bringing about DNA denaturation and compaction. Additionally, molecular dynamics (MD) simulations and quantum mechanics/molecular mechanics (QM/MM) calculations shed light into the binding features of the Ru(II) and Ir(III) complexes and their respective enantiomers toward double-helical DNA, highlighting the important role played by the NËN ancillary ligand once the complexes are covalently linked to DNA. Moreover, metal quantification in the nucleus of SW480 colon adenocarcinoma cells were carried out by inductively coupled plasma-mass spectrometry (ICP-MS), both complexes are more internalized than cisplatin after 4 h of exposition. However, in spite of the dramatic changes in the helicity of the DNA secondary structure induced by these complexes and their nuclear localization, antiproliferative studies have revealed that both, Ru(II) and Ir(III) complexes, cannot be considered cytotoxic. This unexpected behavior can be justified by the fast formation of aquo-complexes, which may react with components of the cell culture medium or the cytoplasm compartment in such a way that they may become deactivated before reaching DNA.
Assuntos
Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , DNA/química , Irídio/química , Simulação de Dinâmica Molecular , Rutênio/química , Tiabendazol/química , Complexos de Coordenação/metabolismo , DNA/metabolismo , Conformação de Ácido NucleicoRESUMO
BACKGROUND: Cellulitis, a frequent cause of admission of adult patients to medical wards, occasionally evolves to sepsis. In this study we analyze the factors related to sepsis development. METHODS: Prospective and observational study of 606 adult patients with cellulitis admitted to several Spanish hospitals. Comorbidities, microbiological, clinical, lab, diagnostic, and treatment data were analyzed. Sepsis was diagnosed according to the criteria of the 2016 International Sepsis Definitions Conference. Multiple logistic regression modelling was performed to determine the variables independently associated with sepsis development. RESULTS: Mean age was 63.4 years and 51.8% were men. Overall 65 (10.7%) patients developed sepsis, 7 (10.8%) of whom died, but only 4 (6.2%) due to cellulitis. Drawing of blood (P < 0.0001) or any (P < 0.0001) culture, and identification of the agent (P = 0.005) were more likely among patients with sepsis. These patients had also a longer duration of symptoms (P = 0.04), higher temperature (P = 0.03), more extensive cellulitis (P = 0.02), higher leukocyte (P < 0.0001) and neutrophil (P < 0.0001) counts, serum creatinine (P = 0.001), and CRP (P = 0.008) than patients without sepsis. Regarding therapy, patients with sepsis were more likely to undergo changes in the initial antimicrobial regimen (P < 0.0001), received more antimicrobials (P < 0.0001), received longer intravenous treatment (P = 0.03), and underwent surgery more commonly (P = 0.01) than patients without sepsis. Leukocyte counts (P = 0.002), serum creatinine (P = 0.003), drawing of blood cultures (P = 0.004), change of the initial antimicrobial regimen (P = 0.007) and length of cellulitis (P = 0.009) were independently associated with sepsis development in the multivariate analysis. CONCLUSIONS: Increased blood leukocytes and serum creatinine, blood culture drawn, modification of the initial antimicrobial regimen, and maximum length of cellulitis were associated with sepsis in these patients.
Assuntos
Celulite (Flegmão)/complicações , Sepse/etiologia , Administração Intravenosa , Idoso , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Hemocultura , Creatinina/sangue , Feminino , Febre/tratamento farmacológico , Humanos , Contagem de Leucócitos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Sepse/tratamento farmacológicoRESUMO
AIMS: To evaluate a prevention strategy implemented to reduce incidence and severity of positioning related pressure injuries affecting pediatric patients in a pediatric critical care unit. Secondary objective was to evaluate compliance with preventive recommendations. BACKGROUND: The skin in infants or children has important physiological and anatomical differences compared with adults. Further, factors such as the immaturity of the skin and limited activity and mobility in pediatric critical care unit, along with the pressure exerted by medical devices, increases the risk of pressure ulcers in infants and children. The most effective preventive measures specific to this intensive care population need to be evaluated. MATERIAL AND METHODS: Quasi-experimental before-after study with consecutive sampling. The effectiveness of the care bundle implementation was evaluated based on the latest evidence (intervention group) versus the application of non-standardized care (control group). Pediatric patients up to 14 years old at risk of suffering from pressure injuries and who were admitted more than 48 h in a pediatric intensive care unit (level III) participated. For the collection of data, two computer programs and the hospital clinical records of each participant were consulted. The data collection period was 6 months per group (pre and post intervention). RESULTS: A sample of 110 patients was obtained (50 control group and 60 intervention group). The cumulative incidence in pediatric patients exposed to the risk of pressure injuries was reduced from 16% to 13.3%; and in the subgroup of patients with prolonged stay (≥28 days), the incidence was reduced from 55.55% to 20%. In the intervention group, category III and IV pressure ulcers were completely reduced. In addition, the total number of pressure injuries decreased by 21.43%. The care bandle recommendations with the highest level of adhesion recorded were: skin inspection, application of hyperoxygenated fatty acids and use of a special support surface. The main risk factor found during the study was the prone position (p < 0.05). CONCLUSIONS: The application of a care bundle for prevention can be an effective solution to reduce the number and severity of LPPs in an intensive care unit. The most vulnerable subgroup of patients may benefit from the application of these resources.