RESUMO
BACKGROUND: The best use of perioperative cardiac biomarkers assessment is still under discussion. Massive postoperative troponin surveillance can result in untenably high workloads and costs for health care systems and potentially harmful interventions for patients. In a cohort of patients at risk for major adverse cardiovascular and cerebrovascular events (MACCEs), we aimed to (1) determine whether preoperative biomarkers can identify patients at major risk for acute myocardial injury in noncardiac surgery, (2) develop a risk model for acute myocardial injury prediction, and (3) propose an algorithm to optimize postoperative troponin surveillance. METHODS: Prospective, single-center cohort study enrolling consecutive adult patients (≥45 years) at risk for MACCE scheduled for intermediate-to-high-risk noncardiac surgery. Baseline high-sensitivity troponin T (hsTnT) and N-terminal fragment of pro-B-type natriuretic peptide (NT-proBNP), as well as hsTnT on the first 3 postoperative days were obtained. The main outcome was the occurrence of acute myocardial injury. Candidate predictors of acute myocardial injury were baseline concentrations of hsTnT ≥14 ng/L and NT-proBNP ≥300 pg/mL and preoperative and intraoperative variables. A multivariable risk model and a decision curve were constructed. RESULTS: Of 732 patients, 42.1% had elevated hsTnT and 37.3% had elevated NT-proBNP levels at baseline. Acute myocardial injury occurred in 161 patients (22%). Elevated baseline hsTnT, found in 84% of patients with acute myocardial injury, was strongly associated with this outcome: odds ratio (OR), 12.08 (95% confidence interval [CI], 7.78-19.42). Logistic regression identified 6 other independent predictors for acute myocardial injury: age, sex, estimated glomerular filtration rate (eGFR) <45 mL·min -1 ·1.73 m -2 , functional capacity <4 METs or unknown, NT-proBNP ≥300 pg/mL, and estimated intraoperative blood loss. The c -statistic for the risk model was 77% (95% CI, 0.73-0.81). The net benefit of the model began at a risk threshold of 7%. CONCLUSIONS: Baseline determination of cardiac biomarkers in patients at risk for MACCE shortly before intermediate- or high-risk noncardiac surgery helps identify those with the highest risk for acute myocardial injury. A baseline hsTnT ≥14 ng/L indicates the need for postoperative troponin surveillance. In patients with baseline hsTnT <14 ng/L, our 6-predictor model will identify additional patients at risk for acute myocardial injury who may also benefit from postoperative surveillance.
Assuntos
Sistema Cardiovascular , Adulto , Humanos , Estudos de Coortes , Estudos Prospectivos , Biomarcadores , Troponina TRESUMO
African swine fever is a highly contagious viral disease of mandatory declaration to the World Organization for Animal Health (OIE). The lack of available vaccines makes its control difficult; thus, African swine fever virus (ASFV) represents a major threat to the swine industry. Inactivated vaccines do not confer solid protection against ASFV. Conversely, live attenuated viruses (LAV), either naturally isolated or obtained by genetic manipulation, have demonstrated reliable protection against homologous ASFV strains, although little or no protection has been demonstrated against heterologous viruses. Safety concerns are a major issue for the use of ASFV attenuated vaccine candidates and have hampered their implementation in the field so far. While trying to develop safer and efficient ASFV vaccines, we found that the deletion of the viral CD2v (EP402R) gene highly attenuated the virulent BA71 strain in vivo Inoculation of pigs with the deletion mutant virus BA71ΔCD2 conferred protection not only against lethal challenge with the parental BA71 but also against the heterologous E75 (both genotype I strains). The protection induced was dose dependent, and the cross-protection observed in vivo correlated with the ability of BA71ΔCD2 to induce specific CD8+ T cells capable of recognizing both BA71 and E75 viruses in vitro Interestingly, 100% of the pigs immunized with BA71ΔCD2 also survived lethal challenge with Georgia 2007/1, the genotype II strain of ASFV currently circulating in continental Europe. These results open new avenues to design ASFV cross-protective vaccines, essential to fight ASFV in areas where the virus is endemic and where multiple viruses are circulating.IMPORTANCE African swine fever virus (ASFV) remains enzootic in most countries of Sub-Saharan Africa, today representing a major threat for the development of their swine industry. The uncontrolled presence of ASFV has favored its periodic exportation to other countries, the last event being in Georgia in 2007. Since then, ASFV has spread toward neighboring countries, reaching the European Union's east border in 2014. The lack of available vaccines against ASFV makes its control difficult; so far, only live attenuated viruses have demonstrated solid protection against homologous experimental challenges, but they have failed at inducing solid cross-protective immunity against heterologous viruses. Here we describe a new LAV candidate with unique cross-protective abilities: BA71ΔCD2. Inoculation of BA71ΔCD2 protected pigs not only against experimental challenge with BA71, the virulent parental strain, but also against heterologous viruses, including Georgia 2007/1, the genotype II strain of ASFV currently circulating in Eastern Europe.
Assuntos
Vírus da Febre Suína Africana/genética , Febre Suína Africana/prevenção & controle , Vacinas Atenuadas/administração & dosagem , Vacinas Virais/administração & dosagem , Febre Suína Africana/imunologia , Febre Suína Africana/virologia , Vírus da Febre Suína Africana/patogenicidade , Animais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Células Cultivadas , Imunização , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/virologia , Suínos , Proteínas Virais/genéticaRESUMO
BACKGROUND: Recommendations on the diagnosis and management of myocardial injury in noncardiac surgery (MINS) show remarkable variability. Mortality reports also vary. We aimed to describe mortality and major adverse cardiovascular and cerebrovascular event (MACCE) rates in patients with silent MINS treated with postoperative aspirin-statin therapy and with cardiology follow-up. METHODS: Prospective descriptive cohort study of patients aged 45 years or older scheduled for noncardiac surgery with high risk for cardiovascular complications from May 2017 to April 2019. Aspirin-statin therapy and cardiology follow-up were prescribed for patients with silent (asymptomatic) MINS. The primary outcome was one-year mortality in patients with silent MINS, diagnosed by troponin concentration. Secondary outcomes were mortality in MINS patients with perioperative myocardial infarction (PMI) or chronic myocardial injury (CMI) and MACCE. RESULTS: We identified 766 eligible patients and enrolled 747. MINS occurred in 166 patients (22.2%); 151 (91%) had silent MINS and 15 (9%) had PMI. Thirty-one patients (4.1%) had CMI. One-year mortality was higher in patients with silent MINS (22.5%) than in patients with no MINS (7.8%) (P<0.001). One-year mortality rates in MINS patients with PMI or CMI were 27 and 19%, respectively. MACCE were more frequent in patients with silent MINS at 30 days and one year (18 and 25%) than in patients with no MINS (6 and 12%, respectively). CONCLUSIONS: Rates of mortality and MACCE in patients with silent MINS were high despite aspirin-statin therapy and cardiology follow-up. Further prospective research is needed to assess new postoperative care protocols that might effectively improve outcomes.
Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases , Infarto do Miocárdio , Humanos , Aspirina/efeitos adversos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Estudos de Coortes , Complicações Pós-Operatórias/etiologia , Incidência , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/etiologia , Fatores de RiscoRESUMO
BACKGROUND AND AIMS: Human epididymal protein 4 (HE4) may be a useful tool in the differential diagnosis of malignant ascites. The aim of this study was to evaluate the diagnostic utility of HE4 for detecting malignant ascites, taking into account the possible false positives identified with adenosine deaminase (ADA), C-reactive protein (CRP), % polynuclear cells (%PMN) and glomerular filtration rate (eGFR). METHODS: Concentrations of HE4, ADA, %PMN and CRP were determined in 114 samples of peritoneal fluid and creatinine in serum in order to calculate eGFR. RESULTS: Concentrations of HE4 presented significant differences (P = 0.028) in benign [median (interquartile range)] [582(372)] pmol/L) and malignant ascites ([8241(367)] pmol/L. Sensitivity was 21.2% and specificity 100%. Significant differences were also observed for HE4 between tumors of gynecological origin ([3165(8769)] pmol/L) and others ([665(663)] pmol/L), with a sensitivity of 67% and a specificity of 100%. Classifying according to possible false positives (ADA > 45U/L, CRP > 50 mg/L, %PMN > 90 and eGFR < 30 mL/min/1.73 m2) at maximum specificity, a sensitivity of 33.3% was obtained for HE4, with a cut-off point of 2660 pmol/L. Without possible false positives (ADA < 45U/L, CRP < 50 mg/L, %PMN < 90 and eGFR ≥ 30 mL/min/1.73 m2), a sensitivity of 37.7% was obtained at 100% specificity for a cut-off point of 1041 pmol/L. Applying these criteria to the entire group, a sensitivity of 36.4% was obtained at maximum specificity. CONCLUSIONS: HE4 allows the identification of malignant ascites with moderate sensitivity at maximum specificity. HE4 levels can differentiate between tumors of gynecological origin and others. Classification according to possible false positives increases sensitivity without losing specificity.
RESUMO
The newly synthesized 11-cis-7-methylretinal can form an artificial visual pigment with kinetic and spectroscopic properties similar to the native pigment in the dark-state. However, its photobleaching behavior is altered, showing a Meta I-like photoproduct. This behavior reflects a steric constraint imposed by the 7-methyl group that affects the conformational change in the binding pocket as a result of retinal photoisomerization. Transducin activation is reduced, when compared to the native pigment with 11-cis-retinal. Molecular dynamics simulations suggest coupling of the C7 methyl group and the beta-ionone ring with Met207 in transmembrane helix 5 in agreement with recent experimental results.
Assuntos
Retinaldeído/análogos & derivados , Rodopsina/metabolismo , Segmento Externo da Célula Bastonete/metabolismo , Transducina/metabolismo , Animais , Células COS , Chlorocebus aethiops , Simulação por Computador , Adaptação à Escuridão , Diterpenos , Proteínas de Ligação ao GTP/metabolismo , Humanos , Modelos Moleculares , Ligação Proteica , Retinaldeído/química , Retinaldeído/metabolismo , Estereoisomerismo , Relação Estrutura-Atividade , Visão Ocular/fisiologiaRESUMO
Detergent-solubilized bovine rhodopsin produces mixed detergent/lipid/protein micelles. The effect of dodecyl maltoside detergent on the thermal stability of dark-state rhodopsin, and upon formation of the different intermediates after rhodopsin photobleaching (metarhodopsin II and metarhodopsin III), and upon transducin activation has been studied. No significant effect is observed for the thermal stability of dark-state rhodopsin in the range of detergent concentrations studied, but a decrease in the stability of metarhodopsin II and an increase in metarhodopsin III formation is observed with decreasing detergent concentrations. The transducin activation process is also affected by the presence of detergent indicating that this process is dependent on the lipid micro-environment and membrane fluidity, and this stresses the importance of the native lipid environment in rhodopsin normal function.
Assuntos
Detergentes/farmacologia , Proteínas de Ligação ao GTP/metabolismo , Glucosídeos/farmacologia , Rodopsina/análogos & derivados , Rodopsina/metabolismo , Relação Dose-Resposta a Droga , Fluorescência , Humanos , Micelas , Rodopsina/fisiologia , Transducina/metabolismoRESUMO
The cytoplasmic sides of transmembrane helices 3 and 6 of G-protein-coupled receptors are connected by a network of ionic interactions that play an important role in maintaining its inactive conformation. To investigate the role of such a network in rhodopsin structure and function, we have constructed single mutants at position 134 in helix 3 and at positions 247 and 251 in helix 6, as well as combinations of these to obtain double mutants involving the two helices. These mutants have been expressed in COS-1 cells, immunopurified using the rho-1D4 antibody, and studied by UV-visible spectrophotometry. Most of the single mutations did not affect chromophore formation, but double mutants, especially those involving the T251K mutant, resulted in low yield of protein and impaired 11-cis-retinal binding. Single mutants E134Q, E247Q, and E247A showed the ability to activate transducin in the dark, and E134Q and E247A enhanced activation upon illumination, with regard to wild-type rhodopsin. Mutations E247A and T251A (in E134Q/E247A and E134Q/T251A double mutants) resulted in enhanced activation compared with the single E134Q mutant in the dark. A role for Thr(251) in this network is proposed for the first time in rhodopsin. As a result of these mutations, alterations in the hydrogen bond interactions between the amino acid side chains at the cytoplasmic region of transmembrane helices 3 and 6 have been observed using molecular dynamics simulations. Our combined experimental and modeling results provide new insights into the details of the structural determinants of the conformational change ensuing photoactivation of rhodopsin.
Assuntos
Citoplasma/metabolismo , Conformação Proteica , Rodopsina/química , Rodopsina/metabolismo , Sequência de Aminoácidos , Animais , Bovinos , Simulação por Computador , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Mutação , Plasmídeos , Rodopsina/genética , Espectrofotometria Ultravioleta , Eletricidade Estática , Relação Estrutura-AtividadeRESUMO
No single molecular mechanism accounts for the effect of mutations in rhodopsin associated with retinitis pigmentosa. Here we report on the specific effect of a Ca2+/recoverin upon phosphorylation of the autosomal dominant retinitis pigmentosa R135L rhodopsin mutant. This mutant shows specific features like impaired G-protein signaling but enhanced phosphorylation in the shut-off process. We now report that R135L hyperphosphorylation by rhodopsin kinase is less efficiently inhibited by Ca2+/recoverin than wild-type rhodopsin. This suggests an involvement of Ca2+/recoverin into the molecular pathogenic effect of the mutation in retinitis pigmentosa which is the cause of rod photoreceptor cell degeneration. This new proposed role of Ca2+/recoverin may be one of the specific features of the proposed new Type III class or rhodopsin mutations associated with retinitis pigmentosa.
Assuntos
Cálcio/química , Mutação , Recoverina/química , Recoverina/genética , Retinose Pigmentar/metabolismo , Rodopsina/química , Rodopsina/genética , Animais , Células COS , Cálcio/metabolismo , Bovinos , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Receptor Quinase 1 Acoplada a Proteína G/metabolismo , Genes Dominantes , Fosforilação , Transducina/metabolismoRESUMO
The naturally occurring mutations G51A and G51V in transmembrane helix I and G89D in the transmembrane helix II of rhodopsin are associated with the retinal degenerative disease autosomal dominant retinitis pigmentosa. To probe the orientation and packing of helices I and II a number of replacements at positions 51 and 89 were prepared by using site-directed mutagenesis, and the corresponding proteins expressed in COS-1 cells were characterized. Mutations at position 51 (G51V and G51L) bound retinal like wild-type rhodopsin but had thermally destabilized structures in the dark, altered photobleaching behavior, destabilized metarhodopsin II active conformations, and were severely defective in signal transduction. The effects observed can be correlated with the size of the mutated side chains that would interfere with specific interhelical interaction with Val-300 in helix VII. Mutations at position 89 had sensitivity to charge, as in G89K and G89D mutants, which showed reduced transducin activation. G89K showed a second absorbing species in the UV region at 350 nm, suggesting a charge effect of the introduced lysine. Increased formation of non-active forms of rhodopsin, like metarhodopsin III, may have some influence in the molecular defect underlying retinitis pigmentosa in the mutants studied. At the structural level, the effect of the mutations analyzed can be rationalized assuming a very specific set of tertiary interactions in the interhelical packing of the transmembrane segments of rhodopsin.