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1.
bioRxiv ; 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38328097

RESUMO

Allosteric HIV-1 integrase (IN) inhibitors (ALLINIs) are investigational antiretroviral agents which potently impair virion maturation by inducing hyper-multimerization of IN and inhibiting its interaction with viral genomic RNA. The pyrrolopyridine-based ALLINI pirmitegravir (PIR) has recently advanced into Phase 2a clinical trials. Previous cell culture based viral breakthrough assays identified the HIV-1(Y99H/A128T IN) variant that confers substantial resistance to this inhibitor. Here, we have elucidated the unexpected mechanism of viral resistance to PIR. While both Tyr99 and Ala128 are positioned within the inhibitor binding V-shaped cavity at the IN catalytic core domain (CCD) dimer interface, the Y99H/A128T IN mutations did not substantially affect direct binding of PIR to the CCD dimer or functional oligomerization of full-length IN. Instead, the drug-resistant mutations introduced a steric hindrance at the inhibitor mediated interface between CCD and C-terminal domain (CTD) and compromised CTD binding to the CCDY99H/A128T + PIR complex. Consequently, full-length INY99H/A128T was substantially less susceptible to the PIR induced hyper-multimerization than the WT protein, and HIV-1(Y99H/A128T IN) conferred >150-fold resistance to the inhibitor compared to the WT virus. By rationally modifying PIR we have developed its analog EKC110, which readily induced hyper-multimerization of INY99H/A128T in vitro and was ~14-fold more potent against HIV-1(Y99H/A128T IN) than the parent inhibitor. These findings suggest a path for developing improved PIR chemotypes with a higher barrier to resistance for their potential clinical use.

2.
Inorg Chem ; 62(42): 17136-17149, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37824401

RESUMO

Two 1D coordination polymers (CPs) with general formula [M(L)(H2O)(AcO)]n, (M = Co (1) or Cd (2), AcO = acetate anion and L denotes l-phenylalanine based ligand), were synthesized and fully characterized by various spectroscopies (UV-vis, FTIR, and NMR), thermal techniques, magnetic measurements (for 1), and single-crystal and powder X-ray diffraction studies. They can be described as "ribbon-like" 1D polymers constructed through a zigzag arrangement. The polymeric structure is developed due to the coordination mode adopted by the amino acid ligand, classified as µ3-N1O1:O1:O2, which simultaneously links three metal centers. This moiety also plays an important role as a magnetic coupler between metal centers in the cobalt system, which shows a weak antiferromagnetic interaction. Both CPs have also been used in the catalytic oxidation of cyclohexene with molecular oxygen (O2) as an oxidant. Under mild conditions, both compounds demonstrated remarkable catalytic activity, with the cobalt system being more efficient than the cadmium analogue (conversion: 73 and 58% and selectivity for the major product, 2-cyclohexanone: 63 and 55%, for 1 and 2, respectively). Leaching experiments and the results obtained using a radical quencher are consistent with a radical-mediated mechanism for the Co compound. The presence of the superoxide radical was also confirmed using EPR spectroscopy and DMPO as a spin trap, which was further validated by DFT calculations. The activity observed for the Cd analogue is attributed to the organic scaffold assisted by the templating effect of the metal ion.

3.
Rev. colomb. psiquiatr ; 52(3)sept. 2023.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1536141

RESUMO

Objetivo: El objetivo de este estudio es analizar la coexistencia de varios síndromes de falsos reconocimientos delirantes en una muestra clínica. Métodos: A lo largo de 1 ano, se seleccionó una muestra de 6 pacientes con 2 o más tipos de falsos reconocimientos delirantes durante el mismo episodio. Todos ellos se encontraban hospitalizados en la unidad de hospitalización psiquiátrica en un hospital de España. Resultados: A pesar de los distintos diagnósticos, los pacientes incluidos presentaban diferentes tipos de falsos reconocimientos delirantes, tanto de hiperidentificación como de hipoidentificación. El tratamiento antipsicótico fue escasamente eficaz contra estos síndromes de falsos reconocimientos delirantes. Conclusiones: La coexistencia de varios síndromes de falsos reconocimientos delirantes indica que la etiopatogenia de los distintos tipos es similar. Se trata de un campo con importantes implicaciones tanto clínicas, por la baja respuesta al tratamiento, como las posibles médico-legales.


Objective: The objective of this study is to analyze the coexistence of several delusional misidentification syndromes in a clinical sample. Methods: Over one year, a sample of six patients presenting two or more types of delusional misidentification syndromes was selected. All these patients were admitted to the psychiatric inpatient unit of a Spanish hospital. Results: Despite the different diagnoses, the patients included presented different types of delusional misidentification syndromes, both hyperidentification and hypoidentification. Antipsychotic treatment was not very effective against these delusional misidentification syndromes Conclusions: The coexistence of several delusional misidentification syndromes indicates that the aetiopathogenesis of the different types is similar. It is a field with important clinical implications, due to the poor response to treatment, as well as the possible medico-legal implications.

4.
Nat Commun ; 14(1): 5149, 2023 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-37620323

RESUMO

The human endogenous retrovirus K (HERV-K) is the most recently acquired endogenous retrovirus in the human genome and is activated and expressed in many cancers and amyotrophic lateral sclerosis. We present the immature HERV-K capsid structure at 3.2 Å resolution determined from native virus-like particles using cryo-electron tomography and subtomogram averaging. The structure shows a hexamer unit oligomerized through a 6-helix bundle, which is stabilized by a small molecule analogous to IP6 in immature HIV-1 capsid. The HERV-K immature lattice is assembled via highly conserved dimer and trimer interfaces, as detailed through all-atom molecular dynamics simulations and supported by mutational studies. A large conformational change mediated by the linker between the N-terminal and the C-terminal domains of CA occurs during HERV-K maturation. Comparison between HERV-K and other retroviral immature capsid structures reveals a highly conserved mechanism for the assembly and maturation of retroviruses across genera and evolutionary time.


Assuntos
Esclerose Lateral Amiotrófica , Retrovirus Endógenos , Humanos , Retrovirus Endógenos/genética , Evolução Biológica , Capsídeo , Proteínas do Capsídeo/genética
5.
bioRxiv ; 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37333227

RESUMO

A significant part of the human genome consists of endogenous retroviruses sequences. Human endogenous retrovirus K (HERV-K) is the most recently acquired endogenous retrovirus, is activated and expressed in many cancers and amyotrophic lateral sclerosis and possibly contributes to the aging process. To understand the molecular architecture of endogenous retroviruses, we determined the structure of immature HERV-K from native virus-like particles (VLPs) using cryo-electron tomography and subtomogram averaging (cryoET STA). The HERV-K VLPs show a greater distance between the viral membrane and immature capsid lattice, correlating with the presence of additional peptides, SP1 and p15, between the capsid (CA) and matrix (MA) proteins compared to the other retroviruses. The resulting cryoET STA map of the immature HERV-K capsid at 3.2 Å resolution shows a hexamer unit oligomerized through a 6-helix bundle which is further stabilized by a small molecule in the same way as the IP6 in immature HIV-1 capsid. The HERV-K immature CA hexamer assembles into the immature lattice via highly conserved dimmer and trimer interfaces, whose interactions were further detailed through all-atom molecular dynamics simulations and supported by mutational studies. A large conformational change mediated by the flexible linker between the N-terminal and the C-terminal domains of CA occurs between the immature and the mature HERV-K capsid protein, analogous to HIV-1. Comparison between HERV-K and other retroviral immature capsid structures reveals a highly conserved mechanism for the assembly and maturation of retroviruses across genera and evolutionary time.

6.
Heart Rhythm ; 20(6): 822-830, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37245897

RESUMO

BACKGROUND: Pharmacological options for rate control in atrial fibrillation are scarce. Ivabradine was postulated to reduce the ventricular rate in this setting. OBJECTIVES: The objectives of this study were to evaluate the mechanism of inhibition of atrioventricular conduction produced by ivabradine and to determine its efficacy and safety in atrial fibrillation. METHODS: The effects of ivabradine on atrioventricular node and ventricular cells were studied by in vitro whole-cell patch-clamp experiments and mathematical simulation of human action potentials. In parallel, a multicenter, randomized, open-label, phase III clinical trial compared ivabradine with digoxin for uncontrolled permanent atrial fibrillation despite ß-blocker or calcium channel blocker treatment. RESULTS: Ivabradine 1 µM inhibited "funny" current and rapidly activating delayed rectifier potassium channel current by 28.9% and 22.8%, respectively (P < .05). The sodium channel current and L-type calcium channel current were reduced only at 10 µM. Ivabradine slowed the firing frequency of a modeled human atrioventricular node action potential by 10.6% and induced a minimal prolongation of ventricular action potential. Thirty-five (51.5%) patients were randomized to ivabradine and 33 (49.5%) to digoxin. The mean daytime heart rate decreased by 11.6 beats/min (-11.5%) in the ivabradine arm (P = .02) vs 19.6 (-20.6%) in the digoxin arm (P < .001), although the noninferiority margin of efficacy was not met (Z = -1.95; P = .97). The primary safety end point occurred in 3 patients (8.6%) on ivabradine and in 8 (24.2%) on digoxin (P = .10). CONCLUSION: Ivabradine produced a moderate rate reduction in patients with permanent atrial fibrillation. The inhibition of funny current in the atrioventricular node seems to be the main mechanism responsible for this reduction. Compared with digoxin, ivabradine was less effective, was better tolerated, and had a similar rate of serious adverse events.


Assuntos
Fibrilação Atrial , Humanos , Ivabradina/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Frequência Cardíaca/fisiologia , Digoxina/uso terapêutico , Antagonistas Adrenérgicos beta/uso terapêutico
7.
Nat Commun ; 14(1): 2014, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37037809

RESUMO

Dimensionality reduction via coarse grain modeling is a valuable tool in biomolecular research. For large assemblies, ultra coarse models are often knowledge-based, relying on a priori information to parameterize models thus hindering general predictive capability. Here, we present substantial advances to the shape based coarse graining (SBCG) method, which we refer to as SBCG2. SBCG2 utilizes a revitalized formulation of the topology representing network which makes high-granularity modeling possible, preserving atomistic details that maintain assembly characteristics. Further, we present a method of granularity selection based on charge density Fourier Shell Correlation and have additionally developed a refinement method to optimize, adjust and validate high-granularity models. We demonstrate our approach with the conical HIV-1 capsid and heteromultimeric cofilin-2 bound actin filaments. Our approach is available in the Visual Molecular Dynamics (VMD) software suite, and employs a CHARMM-compatible Hamiltonian that enables high-performance simulation in the GPU-resident NAMD3 molecular dynamics engine.

8.
Pathogens ; 12(2)2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36839549

RESUMO

The fungus Fusarium oxysporum f. sp. cubense tropical race 4 (syn. Fusarium odoratissimum) (Foc TR4) causes vascular wilt in Musaceae plants and is considered the most lethal for these crops. In Latin America and the Caribbean (LAC), it was reported for the first time in Colombia (2019), later in Peru (2021), and recently declared in Venezuela (2023). This work aimed to analyze the evolution of Foc TR4 in Musaceae in LAC between 2018 and 2022. This perspective contains a selection of topics related to Foc TR4 in LAC that address and describe (i) the threat of Foc TR4 in LAC, (ii) a bibliometric analysis of the scientific production of Foc TR4 in LAC, (iii) the current situation of Foc TR4 in Colombia, Peru, and Venezuela, (iv) medium-term prospects in LAC member countries, and (v) export trade and local food security. In this study, the presence of Foc TR4 in Venezuela and the possible consequences of the production of Musaceae in the long term were reported for the first time. In conclusion, TR4 is a major threat to banana production in Latin America and the world, and it is important to take measures to control the spread of the fungus and minimize its impact on the banana industry. It is important to keep working on the control of Foc TR4, which requires the participation of the local and international industry, researchers, and consumers, among others, to prevent the disappearance of bananas.

9.
mBio ; 14(1): e0356022, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36744954

RESUMO

Allosteric HIV-1 integrase (IN) inhibitors (ALLINIs) are an emerging class of small molecules that disrupt viral maturation by inducing the aberrant multimerization of IN. Here, we present cocrystal structures of HIV-1 IN with two potent ALLINIs, namely, BI-D and the drug candidate Pirmitegravir. The structures reveal atomistic details of the ALLINI-induced interface between the HIV-1 IN catalytic core and carboxyl-terminal domains (CCD and CTD). Projecting from their principal binding pocket on the IN CCD dimer, the compounds act as molecular glue by engaging a triad of invariant HIV-1 IN CTD residues, namely, Tyr226, Trp235, and Lys266, to nucleate the CTD-CCD interaction. The drug-induced interface involves the CTD SH3-like fold and extends to the beginning of the IN carboxyl-terminal tail region. We show that mutations of HIV-1 IN CTD residues that participate in the interface with the CCD greatly reduce the IN-aggregation properties of Pirmitegravir. Our results explain the mechanism of the ALLINI-induced condensation of HIV-1 IN and provide a reliable template for the rational development of this series of antiretrovirals through the optimization of their key contacts with the viral target. IMPORTANCE Despite the remarkable success of combination antiretroviral therapy, HIV-1 remains among the major causes of human suffering and loss of life in poor and developing nations. To prevail in this drawn-out battle with the pandemic, it is essential to continue developing advanced antiviral agents to fight drug resistant HIV-1 variants. Allosteric integrase inhibitors (ALLINIs) are an emerging class of HIV-1 antagonists that are orthogonal to the current antiretroviral drugs. These small molecules act as highly specific molecular glue, which triggers the aggregation of HIV-1 integrase. In this work, we present high-resolution crystal structures that reveal the crucial interactions made by two potent ALLINIs, namely, BI-D and Pirmitegravir, with HIV-1 integrase. Our results explain the mechanism of drug action and will inform the development of this promising class of small molecules for future use in antiretroviral regimens.


Assuntos
Infecções por HIV , Inibidores de Integrase de HIV , Humanos , Regulação Alostérica , Inibidores de Integrase de HIV/farmacologia , Antivirais/uso terapêutico , Infecções por HIV/tratamento farmacológico
10.
Materials (Basel) ; 15(17)2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-36079202

RESUMO

This article describes a model based on concepts of Fracture Mechanics to evaluate the flexural strength of fiber-reinforced concrete (FRC) sections. The model covers the need by structural engineers to have tools that allow, in a simple way, the designing of FRC sections and avoiding complex calculations through finite elements. It consists of an analytical method that models FRC post-cracking behavior with a cohesive linear softening law (σ - w). We use a compatibility equation based on the planar crack hypothesis, i.e., the assumption that the crack surfaces remain plane throughout the fracture process, which was recently proven true using digital image correlation. Non-cracked concrete bulk follows a stress-strain law (σ - ε) combined with the Bernoulli-Navier assumption. We define a brittleness number derived from non-dimensional analyses, which includes the beam size and the softening characteristics. We show that this parameter is key to determining the FRC flexural strength, characterizing fiber-reinforced concrete, and reproducing the size-effect of sections in flexure. Moreover, we propose an expression to calculate the flexural strength of FRC as a function of the cited brittleness number. The model also gives the ratio between the residual strength in service conditions and the flexural strength. Model results show a good agreement with tests in the scientific literature. Finally, we also analyze the brittle-ductile transition in FRC sections.

12.
Plants (Basel) ; 11(15)2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35956549

RESUMO

Over the last few decades, a growing incidence of Banana Wilt (BW) has been detected in the banana-producing areas of the central zone of Venezuela. This disease is thought to be caused by a fungal−bacterial complex, coupled with the influence of specific soil properties. However, until now, there was no consensus on the soil characteristics associated with a high incidence of BW. The objective of this study was to identify the soil properties potentially associated with BW incidence, using supervised methods. The soil samples associated with banana plant lots in Venezuela, showing low (n = 29) and high (n = 49) incidence of BW, were collected during two consecutive years (2016 and 2017). On those soils, sixteen soil variables, including the percentage of sand, silt and clay, pH, electrical conductivity, organic matter, available contents of K, Na, Mg, Ca, Mn, Fe, Zn, Cu, S and P, were determined. The Wilcoxon test identified the occurrence of significant differences in the soil variables between the two groups of BW incidence. In addition, Orthogonal Least Squares Discriminant Analysis (OPLS-DA) and the Random Forest (RF) algorithm was applied to find soil variables capable of distinguishing banana lots showing high or low BW incidence. The OPLS-DA model showed a proper fitting of the data (R2Y: 0.61, p value < 0.01), and exhibited good predictive power (Q2: 0.50, p value < 0.01). The analysis of the Receiver Operating Characteristics (ROC) curves by RF revealed that the combination of Zn, Fe, Ca, K, Mn and Clay was able to accurately differentiate 84.1% of the banana lots with a sensitivity of 89.80% and a specificity of 72.40%. So far, this is the first study that identifies these six soil variables as possible new indicators associated with BW incidence in soils of lacustrine origin in Venezuela.

14.
Rev Port Cardiol ; 41(10): 823-830, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35784098

RESUMO

Background: Chronic use of Angiotensin-converting enzyme (ACE) inhibitors (ACEi) and aldosterone-receptor blockers (ARB) is not associated with worse outcomes in patients with COVID-19. However, evidence on the impact of their discontinuation during hospital admission is scarce. Our aim was to determine whether withdrawal of ACEi, ARB and mineralocorticoid receptor antagonists (MRA) is associated with all-cause mortality in a real-life large cohort of patients with SARS-CoV-2 infection. Methods: Observational cohort study from a large referral center from 1 March 2020 to 20 April 2020. Withdrawal of renin-angiotensin-aldosterone system inhibitors was defined as the absence of any received dose during hospital admission in patients receiving chronic treatment. Prescriptions during admission were confirmed by data from the central pharmacy computerized system. Results: A total of 2042 patients (mean age 68.4±17.6, 57.1% male) with confirmed COVID-19 were included. During a median follow-up of 57 (21-55) days, 583 (28.6%) died. Prior to hospital admission 468 (22.9%), 343 (16.8%) and 83 (4.1%) patients were receiving ACEi, ARB and MRA respectively. During the study period, 216 (46.2%), 193 (56.3%) and 41 (49.4%) were withdrawn from the corresponding drug. After adjusting for age, cardiovascular risk factors, baseline comorbidities and in-hospital COVID-19 dedicated treatment, withdrawal of ACE inhibitors (hazard ration [HR] 1.48 [95% confidence interval -CI- 1.16-1.89]) and MRA (HR 2.01 [95% CI 1.30-3.10]) were shown to be independent predictors of all-cause mortality. No independent relationship between ARB withdrawal and mortality was observed. Conclusion: ACEi and MRA withdrawal were associated with higher mortality. Strong consideration should be given to not discontinuing these medications during hospital admission.


Introdução: O uso crónico de inibidores da ECA (IECA) e de antagonistas dos recetores de aldosterona (ARA) não está associado a resultados piores em doentes com Covid-19. No entanto, a evidência relativa ao impacto da sua retirada durante a admissão hospitalar é escassa. O nosso objetivo foi determinar se a retirada do IECA, ARA e antagonistas dos recetores dos mineralocorticóides (ARM) está associada à mortalidade por todas as causas numa grande coorte real de doentes com infeção por SRA-CoV-2. Métodos: Estudo coorte observacional a partir de um grande centro de referência de 1 de março de 2020 a 20 de abril de 2020. A retirada dos inibidores do sistema RAAS foi definida como a ausência de qualquer dose recebida durante a admissão hospitalar em doentes que recebem tratamento prolongado. As prescrições durante a admissão foram confirmadas por dados do sistema informático da farmácia central. Resultados: Um total de 2042 doentes (idade média de 68,4 ±17,6, 57,1% do sexo masculino) com COVID-19 confirmado foram incluídos. Durante um acompanhamento médio de 57 (21-55) dias, 583 (28,6%) morreram. Conclusão: A retirada do IECA e do ARM foi associada a uma mortalidade mais elevada. Deve ser dada grande atenção para não interromper estes medicamentos durante a admissão hospitalar.


Assuntos
Tratamento Farmacológico da COVID-19 , Idoso , Idoso de 80 Anos ou mais , Aldosterona , Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Angiotensinas , Anti-Hipertensivos/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Renina , Estudos Retrospectivos , SARS-CoV-2
15.
Med Clin (Engl Ed) ; 158(12): 586-595, 2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35693916

RESUMO

Aims and objectives: Statins have been proposed as potentially useful agents for modulating the host response in COVID-19. However, solid evidence-based recommendations are still lacking. Our aim was to study the association between statin use and clinical outcomes in a large cohort of hospitalized patients with SARS-CoV-2 infection, as well as the specific consequences of chronic treatment withdrawal during hospital admission. Material and methods: Retrospective observational study including 2191 hospitalized patients with confirmed SARS-CoV-2 infection. Results: Mean age was 68.0±17.8 years and 597 (27.3%) patients died during follow-up. A total of 827 patients (37.7% of the whole sample), received chronic treatment with statins. Even though they underwent more frequent admissions in critical care units, chronic treatment with statins was not independently associated with all-cause mortality [HR 0.95 (0.72-1.25)]. During the whole hospital admission, 371 patients (16.9%) received at least one dose of statin. Although these patients had a significantly worse clinical profile, both treatment with statins during admission [HR 1.03 (0.78-1.35)] and withdrawal of chronic statin treatment [HR 1.01 (0.78-1.30)] showed a neutral effect in mortality. However, patients treated with statins presented more frequently hepatic cytolysis, rhabdomyolysis and thrombotic/hemorrhagic events. Conclusions: In this large cohort of hospitalized COVID-19 patients, statins were not independently associated with all-cause mortality during follow-up. Clinically relevant statin-associated adverse effects should be carefully monitored during hospital admission.


Antecedentes y objetivos: Se ha especulado que las estatinas pueden ser de utilidad en el tratamiento de pacientes con COVID-19, pero no existen evidencias clínicas sólidas. El objetivo de este trabajo es conocer su utilidad en una cohorte de gran tamaño de pacientes hospitalizados por COVID-19, así como si su retirada se asocia con un peor pronóstico. Material y métodos: Estudio retrospectivo observacional. Se incluyeron 2.191 pacientes hospitalizados con infección confirmada con SARS-CoV-2. Resultados: La edad media fue de 68,0 ± 17,8 años y fallecieron un total de 597 (27,3%) pacientes. Un total de 827 pacientes (37,7% de la muestra) estaban tratados previamente con estatinas. Aunque precisaron con mayor frecuencia de ingreso en camas de críticos, dicho grupo terapéutico no resultó un factor predictor independiente de muerte en el seguimiento [HR 0,95 (0,72-1,25)]. Un total de 371 pacientes (16,9%) recibió al menos una dosis de estatina durante el ingreso. A pesar de ser una población con un perfil clínico más desfavorable, tanto su uso [HR 1,03 (0,78-1,35)] como la suspensión durante el ingreso en pacientes que las recibían crónicamente [HR 1,01 (0,78-1,30)] presentaron un efecto neutro en la mortalidad. No obstante, el grupo con estatinas desarrolló con mayor frecuencia datos de citolisis hepática, rabdomiolisis y más eventos trombóticos y hemorrágicos. Conclusiones: En nuestra muestra, las estatinas no se asociaron de forma independiente a una menor mortalidad en pacientes con COVID-19. En aquellos pacientes que tengan indicación de recibirlas por su patología previa es necesario monitorizar estrechamente sus potenciales efectos adversos durante el ingreso hospitalario.

16.
Acta Crystallogr B Struct Sci Cryst Eng Mater ; 78(Pt 3 Pt 2): 520-536, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35702969

RESUMO

Metalloproteins involved in oxidation-reduction processes in metabolism are fundamental for the wellbeing of every organism. The use of amino-acid-based compounds as ligands for the construction of biomimetic coordination systems represents a promising alternative for the development of new catalysts. Herein is presented a new family of copper, zinc and nickel coordination compounds, which show four-, five- and six- coordination geometries, synthesized using Schiff base ligands obtained from the amino acids L-alanine and L-phenylalanine. Structural analysis and property studies were performed using single-crystal X-ray diffraction data, spectroscopic and electrochemical experiments and DFT calculations. The analysis of the molecular and supramolecular architectures showed that the non-covalent interactions developed in the systems, together with the identity of the metal and the amino acid backbone, are determinants for the formation of the complexes and the stabilization of the resultant geometries. The CuII complexes were tested as candidates for the electrochemical conversion reduction of nitrite to NO, finding that the five-coordinate L-phenylalanine complex is the most suitable. Finally, some insights into the rational design of ligands for the construction of biomimetic complexes are suggested.


Assuntos
Complexos de Coordenação , Aminoácidos , Complexos de Coordenação/química , Cristalografia por Raios X , Ligantes , Fenilalanina , Bases de Schiff/química
17.
Med. clín (Ed. impr.) ; 158(12): 586-595, junio 2022. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-204686

RESUMO

Antecedentes y objetivos:Se ha especulado que las estatinas pueden ser de utilidad en el tratamiento de pacientes con COVID-19, pero no existen evidencias clínicas sólidas. El objetivo de este trabajo es conocer su utilidad en una cohorte de gran tamaño de pacientes hospitalizados por COVID-19, así como si su retirada se asocia con un peor pronóstico.Material y métodos:Estudio retrospectivo observacional. Se incluyeron 2.191 pacientes hospitalizados con infección confirmada con SARS-CoV-2.Resultados:La edad media fue de 68,0 ± 17,8 años y fallecieron un total de 597 (27,3%) pacientes. Un total de 827 pacientes (37,7% de la muestra) estaban tratados previamente con estatinas. Aunque precisaron con mayor frecuencia de ingreso en camas de críticos, dicho grupo terapéutico no resultó un factor predictor independiente de muerte en el seguimiento [HR 0,95 (0,72-1,25)]. Un total de 371 pacientes (16,9%) recibió al menos una dosis de estatina durante el ingreso. A pesar de ser una población con un perfil clínico más desfavorable, tanto su uso [HR 1,03 (0,78-1,35)] como la suspensión durante el ingreso en pacientes que las recibían crónicamente [HR 1,01 (0,78-1,30)] presentaron un efecto neutro en la mortalidad. No obstante, el grupo con estatinas desarrolló con mayor frecuencia datos de citolisis hepática, rabdomiolisis y más eventos trombóticos y hemorrágicos.Conclusiones:En nuestra muestra, las estatinas no se asociaron de forma independiente a una menor mortalidad en pacientes con COVID-19. En aquellos pacientes que tengan indicación de recibirlas por su patología previa es necesario monitorizar estrechamente sus potenciales efectos adversos durante el ingreso hospitalario. (AU)


Aims and objectives:Statins have been proposed as potentially useful agents for modulating the host response in COVID-19. However, solid evidence-based recommendations are still lacking. Our aim was to study the association between statin use and clinical outcomes in a large cohort of hospitalized patients with SARS-CoV-2 infection, as well as the specific consequences of chronic treatment withdrawal during hospital admission.Material and methods:Retrospective observational study including 2191 hospitalized patients with confirmed SARS-CoV-2 infection.Results:Mean age was 68.0±17.8 years and 597 (27.3%) patients died during follow-up. A total of 827 patients (37.7% of the whole sample), received chronic treatment with statins. Even though they underwent more frequent admissions in critical care units, chronic treatment with statins was not independently associated with all-cause mortality [HR 0.95 (0.72-1.25)]. During the whole hospital admission, 371 patients (16.9%) received at least one dose of statin. Although these patients had a significantly worse clinical profile, both treatment with statins during admission [HR 1.03 (0.78-1.35)] and withdrawal of chronic statin treatment [HR 1.01 (0.78-1.30)] showed a neutral effect in mortality. However, patients treated with statins presented more frequently hepatic cytolysis, rhabdomyolysis and thrombotic/hemorrhagic events.Conclusions:In this large cohort of hospitalized COVID-19 patients, statins were not independently associated with all-cause mortality during follow-up. Clinically relevant statin-associated adverse effects should be carefully monitored during hospital admission. (AU)


Assuntos
Humanos , Idoso de 80 Anos ou mais , Coronavirus/efeitos dos fármacos , Hospitalização , Mortalidade , Inibidores de Hidroximetilglutaril-CoA Redutases , Morbidade
18.
Biomimetics (Basel) ; 7(1)2022 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-35225916

RESUMO

Architects throughout the ages have looked to nature for answers to complex questions about the most appropriate structural forms for their buildings. This is the case of Jørn Utzon and the design of roof shells of the Sydney Opera House, in which the search for natural references was constant, from the nautical references in the initial design phases to the final spherical solution based on the analogy with an orange. This paper analyzes the influence of nature as a source of inspiration in this World Heritage building, assessing through FEM calculation models the suitability of the different solutions proposed and weighing up the influence of certain factors such as scale in this type of process. Through the calculation models developed, it has been possible to verify the poor performance of the initial designs compared to the power of the final solution, which, after more than 5 years of research by the design team headed by Utzon, was able to solve the enormous problem with a "simple" typological and geometric change.

19.
Med Clin (Barc) ; 158(12): 586-595, 2022 06 24.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-34511251

RESUMO

AIMS AND OBJECTIVES: Statins have been proposed as potentially useful agents for modulating the host response in COVID-19. However, solid evidence-based recommendations are still lacking. Our aim was to study the association between statin use and clinical outcomes in a large cohort of hospitalized patients with SARS-CoV-2 infection, as well as the specific consequences of chronic treatment withdrawal during hospital admission. MATERIAL AND METHODS: Retrospective observational study including 2191 hospitalized patients with confirmed SARS-CoV-2 infection. RESULTS: Mean age was 68.0±17.8 years and 597 (27.3%) patients died during follow-up. A total of 827 patients (37.7% of the whole sample), received chronic treatment with statins. Even though they underwent more frequent admissions in critical care units, chronic treatment with statins was not independently associated with all-cause mortality [HR 0.95 (0.72-1.25)]. During the whole hospital admission, 371 patients (16.9%) received at least one dose of statin. Although these patients had a significantly worse clinical profile, both treatment with statins during admission [HR 1.03 (0.78-1.35)] and withdrawal of chronic statin treatment [HR 1.01 (0.78-1.30)] showed a neutral effect in mortality. However, patients treated with statins presented more frequently hepatic cytolysis, rhabdomyolysis and thrombotic/hemorrhagic events. CONCLUSIONS: In this large cohort of hospitalized COVID-19 patients, statins were not independently associated with all-cause mortality during follow-up. Clinically relevant statin-associated adverse effects should be carefully monitored during hospital admission.


Assuntos
Tratamento Farmacológico da COVID-19 , Inibidores de Hidroximetilglutaril-CoA Redutases , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Hospitalização , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Pessoa de Meia-Idade , SARS-CoV-2
20.
Cont Lens Anterior Eye ; 45(3): 101448, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-33975785

RESUMO

Myopia is a worldwide major public concern, aside from the visual disturbance needing optical correction, myopia may be associated with open angle glaucoma, retinal detachment and myopic maculopathy. The higher the myopia the higher the risk for retinal associated comorbidities, and the axial length is the more important measure to estimate risk of visual impairment. Recently a formula to predict axial length using spherical equivalent and keratometry was proposed, with the intention of categorizing the risk of visual impairment with Tideman et al. classification. PURPOSE: To evaluate the accuracy of an axial length prediction formula in a Colombian population 8-17 years old. METHODS: Children from MIOPUR study with optical biometer axial length measure (AL), manifest refraction and keratometry were included in the analysis. Predicted axial length (PAL) was calculated with the prediction formula. A Bland-Altman assessment was conducted, and the concordance correlation coefficient was measured. Proposed classification of AL to establish risk of visual loss was used with measured AL and with PAL. The percentage of eyes misclassified was then established. RESULTS: A total of 2129 eyes were included in the analysis. Mean difference of axial length (actual AL minus PAL) was -0.516 mm (-1.559 mm - 0.528 mm). Concordance correlation coefficient (CCC) of 0.656 (IC95 0.636-0.675) was found between the real AL and PAL. PAL differed from measured AL by 1 mm or more in 16.58 %, and by 2 mm or more, in 0.61 % of the eyes. In myopic eyes, PAL was in average 0.426 mm longer than the AL actually measured with CCC of 0.714 (IC95 0.666-0.761). PAL differed from measured AL by 1 mm or more in 21.92 %, and by 2 mm or more, in 0.45 % of the myopic eyes. The study revealed that 15.03 % of all eyes, and 29.81 % of myopic eyes, were misclassified when PAL was used. CONCLUSIONS: The proposed axial length prediction formula was not accurate, and it did not adequately classify risk of visual impairment in myopic eyes in a group of Colombian children. We consider that it is not possible to predict the axial length based only on optometric data, such as the corneal radius of curvature and the spherical equivalent. This is very possibly related to the variability of crystalline lens power within a population.


Assuntos
Glaucoma de Ângulo Aberto , Miopia , Adolescente , Comprimento Axial do Olho , Criança , Córnea , Glaucoma de Ângulo Aberto/complicações , Humanos , Miopia/complicações , Miopia/diagnóstico , Refração Ocular , Testes Visuais
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